Spring 2018: BiPed System Schematics (EagleCAD)

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By: Jorge Hernandez (Electronics & Control Engineer)

Verified By: Miguel Gonzalez (Project Manager)

Approved By: Miguel Garcia (Quality Assurance)

Introduction

After the Fritzing design was completed, an EagleCAD schematic has to be designed to create a PCB in order to move the project forward. EagleCAD is a software program that allows the user to place components on the board, and wire all the connections properly. Pins such as I2C pins can be connected across the network

Here I explain the mistakes I have made and my final schematic for Micro FOBO which has been approved by Gary Hill and Fabian Suske.

Requirements

Level 1:

L1-18: Micro FOBO shall utilize a printable Circuit Board (PCB)

L1-7: Micro FOBO will utilize a 3DoT board (PCB will be mounted on 3DoT board)

Previous Schematics

Fig.1 Previous Schematics

 

 

For my first rough draft at Micro FOBO’s Eagle schematic, I did not implement the 3 DoT shield pin header which was a huge mistake. The reason this is a mistake is that if I did order this board, it would become a floating board which will require extra wires to connect my custom PCB to the 3DoT. As one can see, I also included the 12C TCA9548A Multiplexer, as the Micro FOBO will use 2 UV sensors which require different addresses to read values from each UV sensor. Using the TCA9548A was a mistake because it takes too much space, as it has the ability for 8 different I2C sensors and all we needed was 2. Another mistake which was making pinouts for the HC-SR04 ultrasonic, as that specific ultrasonic required 5V to operate which would have required a booster shield. A trade study for ultrasonics was done and found that the SEN136B5B ultrasonic sensor operates at 3.3V which eliminates a need for a booster shield as all the other components (UV, LED’s, Multiplexer, PCA  Servo Expander) run at 3.3V or less(limiter resistor required).

 

Fig.2 Another Schematic (not approved)

Final Schematic Ordered

 

Fig.3 Final Schematic

Instead of individual resistors that protect the PWM of the Servo Expander, Hill suggested a resistor package for routing simplicity and a cleaner look (SO16 package). Another major change was to simply ground all address (A0-A5) on the Servo Expander to use the default address on that chip. 3DoT pin headers were introduced which will make this PCB sit on the 3Dot and not have loose wiring connections between these two boards. Voltage declarations were updated as everything operates at 3.3V other than the 8 Micro Servos, which will operate together, require an outside power source and therefore are connected to VBATT. Changing our multiplexer to the PCA9540BDPN was critical, as it is a 2 channel multiplexer which will save space on the PCB, compared to the 8 channel multiplexer from the previous schematics.

Conclusion

The completed Fritzing diagram and the Eagle schematic move our project closer to mission success. We now have a concrete version of our schematic and how each component is connected to each other.  This is then sent to the Manufacturing Engineer and Project Manager to be approved. Once approved, the board layout (routing) will be completed.

References

  1. https://www.arxterra.com/fall-2016-velociraptor-eaglecad-schematic/
  2. https://www.arxterra.com/spring-2016-rofi-pcb-design-alternative-arduinos-and-custom-eagle-components/

 

Spring 2018: Biped Lessons Learned

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Written By: Miguel Gonzalez (PM and Manufacturing)

Approved By: Miguel Garcia (Quality Assurance)

Table of Contents

Introduction

EE 400D is a very fast pace class in which students are expected to learn new material on their own to succeed with their group project. At first, everything may become stressful with all the new information given to you about how the class structure is set up. Hopefully, you were instructed to look at previous student blog posts to get an understanding of what is expected of you. It is important you take the researching phase of the semester seriously. The success of your project is highly dependent on you and your team in understanding how to setup your semester schedule base on the work you need to do.

This blog post covers all the struggles my team and I had throughout the semester and provide advice on how to prevent your team from encountering issues with your own project. I urge the reader to look at other groups “lessons learned” blog post as some problems students encounter are not robot dependent and some may have other solutions/strategies on how they solved them or prevent them.

Hardships that faced the Micro FOBO group

  • Our group was small. Since the start of the semester, it became evident that our class had fewer students than other semesters. For this reason, our class had only two group projects each of which had three students working on them.  With only three members on the team, the PM had to do the Design and Manufactures job which doubled the workload.
  • We struggled to find the right project to work on. I suggest choosing something that you are passionate about. It wasn’t until I designed the Micro FOBO to emulate 1950s tin toys that I got passionate about the project. What I’m trying to say is that you need to make the project related to you and your teammates add some personal touches. Only then you will find yourself doing work on the project without thinking of it as work
  • 3DoT Board was never given to use to use. Professor Hill worked hard on version 6 of the board but unfortunately, the board encountered problems that delayed the manufacturing of the board.

Things I wish I did not do

  • Spend to much time on the PCB board that did not work
  • Start team meetings without having an agenda/plan made beforehand
  • Do not spend all semester without a single visit you the customer’s office hours. I recommend updating the customer on your project at least twice a month.
  • Do not miss any days of class and try to be on time. Pop quizzes often occur the days you are absent

Things I wish I did do

  • Talked to my teammates about their individual roles and make sure they know what tasks they are responsible for.
  • Set strict timelines for the group
  • Read the class lectures a week in advance and ask questions about any concerns I may have had about the lecture the professor as soon I saw him.
  • I wish I emailed the TA and the Professor more about questions I had. They typically respond quickly to your emails.
  • Update the Customer with your process as much as you can. The customer will always try to help you out with any issues or struggles your team may be having. It will also prevent your team from doing things that the customer does not want and can save you a lot of time in the future.
  • Become acquainted with the QA engineer and make sure he/she knows about any changes or updates your team has on the process of your project.

Things I wish I learned/knew

  • Task Matrix was initially hard to understand and its benefits were overlooked
  • Download and learn SolidWorks early in the semester
  • You can always get waivers/approval of things that violate the requirements if you ask the customer. The customer can be understanding of special situations if valid reasonings are provided.
  • Take a deep dive in the resources available in professor Hill’s class website. There are many hidden outlines and resources that provide great value to the success of your project. But be cautious of any outdated material as Professor Hill tends to change things from semester to semester. If you are not sure the material is relevant, just ask.

Advice for future generations

  • Choose your job positions wisely an understand what the job entails. Software engineers typically have a large workload, I advise them to start work early and to ask for help.
  • Make sure the team reads past blogs as they are very useful. You should do heavy research on Arxterra, Professor Hill’s class website, and other sites early in the semester but I suggest you constantly look back on past project blogs whenever you need clarification on task or need examples. Tip: look at the score the blog posts received to differentiate the good post from the bad.
  • Get a prototype working ASAP. You and your team need to be able to visualize the tasks needed to make your robot work by the end of the semester. You can simply try to get the pass semester’s robot to work and begin revisions from there.
  • Plan to make many versions of your robot. You will never be able to design your robot perfectly at the start. That’s okay, just try to 3D print the model and assemble it together. Then you can begin to understand what things you need to revise to make it work. Our group made 3 full 3D printed iterations of the Micro FOBO with some parts having 6 different versions.
  • Make the meeting minutes as soon as you finish having a team meeting. I highly suggest spending 20 minutes after each meeting writing down what your team did for that day. Make a spot on the meeting minutes for “Homework/Things to do before the next meeting section” and assign group members with the task that they should work on in their own time and before the next meeting. Make a Google Drive Folder with all meeting minutes and share them with all your group members and the customer so they can remain updated with any progress your team is making. Look at our group’s meeting minutes folder as an example of how you can make your own.
  • When doing your Preliminary Design Presentations make sure you follow the Outline provided on the class website. Memorize your sections in your presentation. Do not read from the slides and be prepared to answer questions from the customer.

References

  1. https://www.arxterra.com/spring-2018-micro-fobo-mechanical-drawings/#Part_8_Head
  2. https://drive.google.com/drive/folders/1bzvTSt94itM0pMu-n45xOdocnJpQBtAC

Spring 2018: Project BiPed: Verification and Validation Pass/Fail Matrix

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By: Jeffrey De La Cruz (Mission, Systems, and Test Engineer)

Verified By: Miguel Gonzalez (Project Manager)

Approved By: Miguel Garcia (Quality Assurance)

Table of Contents

Introduction

The Level 1 and Level 2 requirements verification pass/fail matrix will demonstrate if the BiPed functions properly. Each requirement state will be tested by a specific verification method. The verification methods consist of Test, Analysis, Demonstration, and Inspection. As project BiPed continues, the results tools, procedure, and results section will be filled depending on the level requirement. This will determine whether the level requirements pass or fail the verification. The Level 1 and Level 2 requirements are separated in order.

Purpose

The purpose of this document is to provide a comprehensive Verification and Validation (V&V) Test Plan of the Spring 2018 Micro FOBO, including the Project ConOps/Mission, Test Methodology, Verification and Validation Matrices, and Test Cases.

 

Project ConOps/Mission

The mission is to create a toy robot that can be controlled and navigate the toy robot through a 2D maze. The toy robot would then be capable to travel through the maze repeating the same route from its first walkthrough of the maze.

Document Overview

This document is organized as follows:

  • Section 2 contains links to relevant and applicable project reference documents and presentations for this Test Plan.
  • Section 3 contains a description of the Testing Methodology utilized in this Test Plan, including the Master Verification and Validation Matrix, a description of the 4 types of V&V testing performed, the Test Environment(s) description(s), and a Master Test Case List of all (number #) Test Cases for this project.

Applicable Documents

This section contains a table of all relevant and applicable project reference documents and presentations for the Micro FOBO Spring 2018 Verification and Validation Test Plan.

Document Name Document Description Document Link
Research for Micro FOBO Contains research for Micro FOBO. Links to documents helpful to work on Micro FOBO. Research
Project BiPed Website Contains information regarding Jonathon Dowdall’s FOBO FOBO
PDD Preliminary Design Document. Contains xxxxxx PDD
PDR Preliminary Design Review Presentation. Contains L1 and L2 Requirements, System Block Diagram, Resource Allocation Reports, trade studies,xxxxxx PDR
Final Project Summary Final Presentation of completed Project. Contains xxxxxx Currently not available
NASA Systems Engineering Handbook (2007) Document containing Test Methodologies in Section 3 http://www.acq.osd.mil/se/docs/NASA-SP-2007-6105-Rev-1-Final-31Dec2007.pdf

Testing Methodology

This section contains the Master Verification and Validation Matrix, as well as detailed descriptions of the various Test Methods and Test Cases utilized in this Test Plan.

Master Verification and Validation (V&V) Matrix

This matrix provides complete traceability of every requirement. Specifically, every requirement is mapped to its description, success criteria, V&V testing designation and method, and Test Case(s) where the requirement will be tested. Note that some overlap between Test Cases’ requirements V&V is okay.

Level One Requirements

Requirement Number Requirement Text Verification Success Criteria Verification Method (Test, Analysis, Demonstration, Inspection) Test Case #
L1-1 Micro FOBO will stand on its own without any physical help. Micro stands on its own without any assistance. Inspection 2
L1-2 Micro FOBO’s electronic components will be easily assembled and disassembled from the robot’s head. Micro FOBO’s electronic components are easily assembled and disassembled from the robot’s head Inspection 2
L1-3 Micro FOBO will have 2 legs Micro FOBO has two legs. Inspection 2
L1-4 Micro FOBO will be a toy robot based on the design of the FOBO from Jonathan Dowdall. Micro FOBO is a toy robot based on Jonathan Dowdall Inspection 1
L1-5 Micro FOBO will fit within the classroom cabinets. 28”x13”x14.5” Micro FOBO fits in the cabinet within those dimensions Inspection 5
L1-6 Micro FOBO will utilize a 3DoT board or Sparkfun Pro Micro 3.3V/8MHz. Micro FOBO utilizes a 3DoT board or Sparkfun Pro Micro 3.3V/8MHz Inspection 2
L1-7 Micro FOBO’s part components will be 3D printed using the material carbon fiber PLA Micro FOBO’s parts are 3D printed using carbon fiber PLA Inspection 1
L1-8 Micro FOBO will not exceed a print time of 7.80 hours. Upon approval of waiver Micro FOBO does not take longer than 7.80 hours to print. Inspection 1
L1-9 Micro FOBO shall not exceed a cost of $250.00 to construct. Cost does not exceed $250.00 Inspection 5
L1-10

 

 Micro FOBO shall be 63% of the overall size of Jonathan Dowdall’s FOBO. Micro FOBO is smaller than original FOBO by 63% or less

 

 Inspection/Analysis

 

 2
L1-11 Micro FOBO shall detect intersections of the maze. Micro FOBO detects intersections of the maze. Demonstration 3
L1-12 Micro FOBO shall be able to perform static walking Micro FOBO performs static walking Inspection 3
L1-13 Micro FOBO shall produce a 90-degree turn. Micro FOBO turns Demonstration 3
Requirement Number Requirement Text Verification Success Criteria Verification Method (Test, Analysis, Demonstration, Inspection) Test Case #
L1-14 The user shall guide the Micro FOBO through the maze with the use of the Arxterra application. The user guides the Micro FOBO through the maze using the Arxterra application Demonstration 3
L1-15 Micro FOBO shall record the path of the maze Micro FOBO records the path of the maze Demonstration 3
L1-16 Micro FOBO shall traverse the maze using the recorded path. Micro FOBO traverses the maze using the recorded path Demonstration 3
L1-17 Micro FOBO shall traverse cloth, paper, and linoleum. Micro FOBO walks on cloth, paper, and linoleum. Demonstration 4
L1-18 Micro FOBO will utilize a printable circuit board. Micro FOBO utilizes a printable circuit board. Inspection 2
L1-19 The final biped shall be physically completed by May 10, 2018 Micro FOBO is physically completed by May 10, 2018 Inspection 1
L1-20 Micro FOBO should step over a square rod 1cm tall by 1cm wide by 10 cm long Micro FOBO steps over a square rod of 1cm tall by 1cm wide by 10cm long. Demonstration 4
L1-21 Micro FOBO should be able to perform dynamic walking. Micro FOBO performs dynamic walking Demonstration 3

Level Two Requirements

Requirement Number Requirement Text Verification Success Criteria Verification Method (Test, Analysis, Demonstration, Inspection) Test Case #
L2-1 Micro FOBO will be connected via Bluetooth to the app on an android phone Micro FOBO connects via Bluetooth Demonstration 3
L2-2 Micro FOBO dimensions of robot will need to be small enough to fit in a 4in by 4in box for maze purposes. Micro FOBO fits in the 4in by 4in square of the maze. Inspection 5
L2-3 Micro FOBO will use eight micro servos. Micro FOBO has eight micro servos Inspection 2
L2-4 Micro FOBO will use UV sensors to detect the colors of the maze. Micro FOBO UV sensor detects the colors of the maze Demonstration 2
L2-5 By detecting the colors of the maze, the Micro FOBO shall determine if it is at an intersection. (intersection detection) Using the colors of the maze, Micro FOBO detects an intersection Test 3
L2-6 Micro FOBO shall use a battery that outputs 3.7V Test 2
L2-7 The user shall use the Arxterra application to move the robot forward, left, and right. Micro FOBO moves forward, left and right. Test 3
L2-8 Micro FOBO’s wiring shall be able to connect and reconnect in 10 min or less The wiring for Micro FOBO’s connects in 10 min or less. Inspection 1
Requirement Number Requirement Text Verification Success Criteria Verification Method (Test, Analysis, Demonstration, Inspection) Test Case #
L2-9 Micro FOBO wiring shall be nice and clean with the usage of terminal blocks, contact pins, 2.0mm PH series JST connectors, and barrel connectors Micro FOBO’s wiring is nice and clean using terminal blocks, contact pins, 2.0mm PH series JST connectors, and barrel connectors. Demonstration/inspection 1
L2-10 Micro FOBO shall play a musical tune when the maze is completed Micro FOBO plays a musical tun when the maze is completed. Inspection 4
L2-11 Micro FOBO shall have indicating LEDs to demonstrate if micro FOBO is on. Micro FOBO has LEDs and the LEDs turn on. These LEDs  indicate whether its on. 2
L2-12 Micro FOBO shall record the path of the maze the Micro FOBO traverses on the 3DoT board or the Sparkfun Pro Micro 3.3V/8MHz to navigate the robot through the maze. Micro FOBO records the path of the maze and navigates micro FOBO through the maze. Demonstration 3
L2-13 Micro FOBO shall use a 3D printed carbon fiber PLA head chassis and leg components. Micro FOBO’s head chassis and leg components are 3D printed using the carbon fiber PLA. Inspection 1
L2-14 Micro FOBO shall measure 4.5” x 3.25” x 7.25” (l x w x h) Micro FOBO measures 4.5” x 3.25” x 7.25” (l x w x h) Inspection/Analysis 2
L2-15 Micro FOBO shall weigh 460g Micro FOBO weighs at or near 460 grams. 2
L2-16 Micro FOBO shall detect objects 8 inches from it. Micro FOBO detects an object 8 inches from it Demonstration 3
L2-17 Micro FOBO should be able detect other robots and avoid collision. Micro FOBO should stop completely and wait for command Micro FOBO detects other robots in the maze and stops. It stops and awaits command. Demonstration 3
L2-18 Micro FOBO should take a bow at the end of the maze. Micro FOBO takes a bow at the end of the maze. Demonstration 4

Testing Types and Methods

This subsection contains the 4 types of Verification and Validation (V&V) testing, as derived from the NASA Systems Engineering Handbook referenced above in Section 2. The material is taken from Chapter 5 in the NASA Handbook and replicated below.

Verification proves that a realized product for any system model within the system structure conforms to the build-to requirements (for software elements) or realize-to specifications and design descriptive documents (for hardware elements, manual procedures, or composite products of hardware, software, and manual procedures). In other words, Verification is requirements driven; verification shows proof of compliance with requirements; that the product can meet each “shall” statement as proven through a performance of a test, analysis, inspection, or demonstration.

Validation is conducted under realistic conditions (or simulated conditions) on an end product for the purpose of determining the effectiveness and suitability of the product for use in mission operations by typical users; and the evaluation of the results of such tests. Testing is the detailed quantifying method of both verification and validation. However, testing is required to validate final end products to be produced and deployed. In other words, Validation is ConOps/Mission-driven; validation shows that the product accomplishes the intended purpose in the intended environment; that product meets the expectations of the customer and other stakeholders as shown through the performance of a test, analysis, inspection, or demonstration.

Verification by Analysis

The use of mathematical modeling and analytical techniques to predict the suitability of a design to stakeholder expectations based on calculated data or data derived from lower system structure end product verifications. Analysis is generally used when a prototype; engineering model; or fabricated, assembled, and integrated product is not available. Analysis includes the use of modeling and simulation as analytical tools. A model is a mathematical representation of reality. A simulation is the manipulation of a model.

Verification by Demonstration

Showing that the use of an end product achieves the individual specified requirement. It is generally a basic confirmation of performance capability, differentiated from testing by the lack of detailed data gathering. Demonstrations can involve the use of physical models or mockups; for example, a requirement that all controls shall be reachable by the pilot could be verified by having a pilot perform flight-related tasks in a cockpit mockup or simulator. A demonstration could also be the actual operation of the end product by highly qualified personnel, such as test pilots, who perform a one-time event that demonstrates a capability to operate at extreme limits of system performance, an operation not normally expected from a representative operational pilot.

Verification by Inspection

The visual examination of a realized end product. Inspection is generally used to verify physical design features or specific manufacturer identification. For example, if there is a requirement that the safety arming pin has a red flag with the words “Remove Before Flight” stenciled on the flag in black letters, a visual inspection of the arming pin flag can be used to determine if this requirement was met.

Verification by Test

The use of an end product to obtain detailed data needed to verify performance, or provide sufficient information to verify performance through further analysis. Testing can be conducted on final end products, breadboards, brass boards or prototypes. Testing produces data at discrete points for each specified requirement under controlled conditions and is the most resource-intensive verification/validation technique. As the saying goes, “Test as you fly, and fly as you test.” (See Subsection 5.3.2.5.).

Validation by Analysis

The use of mathematical modeling and analytical techniques to predict the suitability of a design to stakeholder expectations based on calculated data or data derived from lower system structure end product validations. It is generally used when a prototype; engineering model; or fabricated, assembled, and integrated product is not available. Analysis includes the use of both modeling and simulation.

Validation by Demonstration

The use of a realized end product to show that a set of stakeholder expectations can be achieved. It is generally used for a basic confirmation of performance capability and is differentiated from testing by the lack of detailed data gathering. Validation is done under realistic conditions for any end product within the system structure for the purpose of determining the effectiveness and suitability of the product for use in NASA missions or mission support by typical users and evaluating the results of such tests.

Validation by Inspection

The visual examination of a realized end product. It is generally used to validate physical design features or specific manufacturer identification.

Validation by Test

The use of a realized end product to obtain detailed data to validate performance or to provide sufficient information to validate performance through further analysis. Testing is the detailed quantifying method of both verification and validation but it is required in order to validate final end products to be produced and deployed.

Master Test Case List

A Test Case can be described as a scenario containing a sequence of detailed test steps, in order to perform verification/validation testing on multiple requirements that are similar in nature.

For example, if a group has multiple requirements regarding starting up their robot project, they can group all these requirements to be verified/validated in a single test case. Similarly, if a group has multiple requirements that can be verified/validated via inspection, they can group all of them together in a single test case.

The purpose of this subsection is to provide a High-Level overview of all Test Cases utilized in this Test Plan. Each item in this subsection will contain the following: Test Case Number and Name, High-Level Scenario Description, and Test Environment Description.

TC-01: Creation, Construction, and Completion of Micro FOBO

Description: Micro FOBO is a toy biped robot based on the design of Jonathon Dowdall’s FOBO. Micro FOBO will be 3D printed using the carbon fiber PLA and will not exceed a print time of 7.80 hours. The head chassis and leg components will be 3D printed using this material. Micro FOBO’s wiring connection does not take more than 10 min and it will contain the usage of terminal blocks, contact pins, 2.0mm PH series JST connectors and barrel connectors. The final physical rendition of micro FOBO shall be completed by May 10, 2018. This test case describes the creation, construction, and completion of micro FOBO. The design, the material used on the components, the print time and the date is described in this test case. These requirements are grouped together because of the conditions of the creation and completion of micro FOBO.

Test Environment: The test case takes place in a classroom.

TC-02: Physical Attributes of Micro FOBO

Description:  This test case consists of anything physical attributes of the micro FOBO. While the previous test case discusses the creation and completion of micro FOBO, this test case will include the requirements that micro FOBO has physically. Micro FOBO electronics components will be easily assembled and disassembled. It will contain two legs that will help it stands on its own without any physical help from the group. A total of 8 servos will be in the legs. Micro FOBO overall size is about 60% of the overall size of Jonathon Dowdall’s FOBO. The dimensions of micro FOBO are: 4.5”x3.25”x7.25”(l x w x h). On the left and right side of micro FOBO’s head, it will contain one LED on each side to indicate whether its turning left or right. Micro FOBO will include a UV sensor to detect colors, will include a custom PCB for sensors and servos, a battery that outputs 3.7 V, a 3DOT board or Pro Micro 3.3V/8MHz. Micro FOBO weight will not exceed 460g. These are grouped together because these are qualities of micro FOBO that are physical.

Test Environment: These test cases take place inside of a classroom.

TC-03: Functionality of Micro FOBO

Description: Functionality of micro FOBO test case consists anything micro FOBO will do to function properly and also the connection and utility of the Arxterra application. This consists of micro FOBO’s ability to detect intersections using the colors of the maze and determine whether to turn and make a 90-degree turn. Micro FOBO functionality to perform a static walk and/or dynamic walk. This test case also contains the user guide of micro FOBO through the maze by connecting the micro FOBO via Bluetooth to the Arxterra application, the recording of the path of the maze, and micro FOBO’s traversing the maze using the recorded path. The user can make the micro FOBO turn forward, turn left, and turn right. Lastly, the micro FOBO detects objects 8 inches from it and should be able to detect other robots and avoid collisions.

Test Environment: This test case will take place inside a classroom

TC-04: Micro FOBO’s Extra Functionality and Challenges

Description: This test case discusses extra functionality the micro FOBO performs whether it being on the maze or on the table and challenges and/or obstacles. For example, a challenge that micro FOBO can perform is walking on different terrain field like linoleum, cloth, and paper. Another challenge for micro FOBO will be to walk over a square rod that measure 1cm tall, 1 cm wide and 10 cm long. Micro FOBO playing a musical tune and taking a bow when it finishes the maze. These requirements were grouped together because these requirements are extra functionality and challenges for micro FOBO.

Test Environment: This test case will take place inside a classroom.

TC-05: Cost, Storage, Fitting in Maze Dimensions

Description: This test case consists of micro FOBO’s cost, being able to fit in ECS 316 cabinets for storage, and being able to fit the 4 in by 4 in maze squares. These requirements were grouped together because these requirements did not relate to any of the previous test cases.

Test Environment: This test case will take place inside a classroom.

Test Procedures

This section contains details of every Test Case utilized for V&V of project requirements. Each Test Case subsection within this section will contain the following: Test Case number and name, detailed scenario description, Test Case Traceability Matrix, detailed success criteria, detailed Test Environment description, Test Assumptions/Preconditions, Detailed Test Procedure Steps, and a Pass/Fail Matrix of success criteria per Test Case.

TC-01: Creation Construction, and Completion of Micro FOBO

Detailed Description

 

This is test case describes the creation, construction, and completion of micro FOBO. For each aspect of creation construction, and completion provides certain conditions of how micro FOBO is physically done. It is going from the step of being 3D printed to assembling it together to being completed. The goal of this test case to demonstrate this and the requirements grouped for this test case are essential for the micro FOBO to be created, constructed and completed.

Test Case Traceability and Pass/Fail Matrix

This matrix shall show all requirements that are being tested in this test case. The Pass/Fail Column is populated after the Test Case has been run via the Procedure Steps.

Requirement Number Requirement Text Verification Success Criteria Verification Method (Test, Analysis, Demonstration, Inspection) Pass/Fail
L1-4 Micro FOBO will be a toy robot based on the design of the FOBO from Jonathan Dowdall. Micro FOBO is a toy robot based on Jonathan Dowdall Inspection Pass
L1-7 Micro FOBO’s part components will be 3D printed using the material carbon fiber PLA Micro FOBO’s parts are 3D printed using carbon fiber PLA Inspection Pass
L1-8 Micro FOBO will not exceed a print time of 7.80 hours. Upon approval of waiver Micro FOBO does not take longer than 7.80 hours to print. Inspection Pass
L1-19 The final biped shall be physically completed by May 10, 2018 Micro FOBO is physically completed by May 10, 2018 Inspection Pass
L2-8 Micro FOBO’s wiring shall be able to connect and reconnect in 10 min or less The wiring for Micro FOBO’s connects in 10 min or less. Inspection Pass
L2-9 Micro FOBO wiring shall be nice and clean with the usage of terminal blocks, contact pins, 2.0mm PH series JST connectors, and barrel connectors Micro FOBO’s wiring contains these type of wires and it is nice and clean. Inspection Pass
L2-13 Micro FOBO shall use a 3D printed carbon fiber PLA head chassis and leg components. Micro FOBO’s head chassis and leg components are 3D printed using the carbon fiber PLA. Inspection Pass

Detailed Success Criteria

In order for this test case to be successful, each of the requirements needs to pass. The goal of this test case will demonstrate that micro FOBO is physically complete beginning from being 3D printed to being built piece by piece. Therefore, the title of this test case goes to explain micro FOBO’s creation, construction, and completion.

Test Environment

This test case will be taking place in the ECS building in room 316. This is where each step of the test case will be presented and show the physically complete micro FOBO.

Assumptions and Preconditions

  • 3D printer will function properly and print parts successfully

Procedure Steps

Step Number Step Description Pass Criteria Recorded Data Requirement(s) Tested Test Method
1 Inspect Jonathon Dowdall’s FOBO and compare it with micro FOBO Micro FOBO Is a toy robot based on Jonathon Dowdall’s FOBO L1-4 Inspection
2 Examine micro FOBO and determine and compare with different material used in 3D printed. Micro FOBO’s parts are 3D printed using the carbon fiber PLA. L1-7 Inspection
3 Examine the print time of the mini FOBO. The print time document is here. The total print time should not exceed a time of 7.80 hours L1-8 Inspection
4 Place a physically completed micro FOBO on the table The completed micro FOBO  is physically ready by May 10 2018. L1-19 Inspection
5 With none of the wires connected, the assembly of micro FOBO will be demonstrated. Once the it is assembled, micro FOBO will then be disassembled. The assembly and disassembly for micro FOBO will not exceed the time of 10 mins. L2-8 Demonstration
6 During assembly, the wires will be inspected and determined whether the correct The wiring of micro FOBO is nice and clean and uses 2.0mm PH series JST connectors and barrel connectors. L2-9 Inspection
7 Inspecting the micro FOBO’s head chassis and leg components, it will be determined if the material carbon fiber PLA is used. Micro FOBO’s head chassis and leg components are 3D printed using carbon fiber PLA L2-13 Inspection

TC-02: Physical Attributes of Micro FOBO

Detailed Description

The Physical Attributes of Micro FOBO test case discusses every components and equipment that the micro FOBO has or utilizes. For example, micro FOBO requires 8 servos in order to stand and to walk. Anything that describes that the micro FOBO needs physically in order to walk through the maze will be in this test case. The goal of this test case is to demonstrate the physical attributes that micro FOBO will need and utilize.

Test Case Traceability and Pass/Fail Matrix

This matrix shall show all requirements that are being tested in this test case. The Pass/Fail Column is populated after the Test Case has been run via the Procedure Steps.

Requirement Number Requirement Text Verification Success Criteria Verification Method (Test, Analysis, Demonstration, Inspection) Pass/Fail
L1-1 Micro FOBO will stand on its own without any physical help. Micro stands on its own without any assistance. Inspection Pass
L1-2 Micro FOBO’s electronic components will be easily assembled and disassembled. Micro FOBO’s electronic components are easily assembled and disassembled Inspection Pass
L1-3 Micro FOBO will have 2 legs Micro FOBO has two legs. Inspection Pass
L1-6 Micro FOBO will utilize a 3DoT board or Sparkfun Pro Micro 3.3V/8MHz. Micro FOBO utilizes a 3DoT board or Sparkfun Pro Micro 3.3V/8MHz Inspection Pass
L1-10 Micro FOBO shall be 63% of the overall size of Jonathan Dowdall’s FOBO. Micro FOBO is smaller than original FOBO by 63% or less

 

 Inspection Pass
L1-18 Micro FOBO will utilize a printable circuit board. Micro FOBO utilizes a printable circuit board. Inspection Pass
L2-3 Micro FOBO will use eight micro servos. Micro FOBO has eight micro servos Inspection Pass
L2-4 Micro FOBO will use UV sensors to detect the colors of the maze. Micro FOBO UV sensor detects the colors of the maze Inspection Pass
L2-6 Micro FOBO shall use a battery that outputs 3.7V A battery that outputs 3.7V is used. Inspection Pass
L2-11

 

 Micro FOBO shall have indicating LEDs to demonstrate if micro FOBO is on. Micro FOBO has LEDs and the LEDs turn on. These LEDs  indicate whether its making a left or right turn. Inspection

 

 Pass
L2-14 Micro FOBO shall measure 4.5” x 3.25” x 7.25” (l x w x h) Micro FOBO measures 4.5” x 3.25” x 7.25” (l x w x h) Demonstration Pass
L2-15 Micro FOBO shall weigh 460g Micro FOBO weighs at or near 460 grams. Inspection Pass

Detailed Success Criteria

In order for this test case to be successful, the physical components of the micro FOBO need to present. Each of the requirements of this test case are needed for the micro FOBO to even begin to navigate the maze. Without some of these requirements, micro FOBO would not be able to perform properly. For example, micro FOBO requires two legs and these two legs will help the micro FOBO to be able to stand without any assistance.

Test Environment

This test case will be taking place in the ECS building in room 316.

Assumptions and Preconditions

  • The 3D printed parts were printed properly
  • Micro FOBO was constructed properly

Procedure Steps

Step Number Step Description Pass Criteria Recorded Data Requirement(s) Tested Test Method
1 Micro FOBO will be placed on a flat surface. Once placed on a flat surface, micro FOBO stands without L1-1 Inspection
2 Micro FOBO assembly is demonstrated. The ease of the assembly and disassembly will be Micro FOBO is easily assembled and disassembled. L1-2 Inspection
3 A completed Micro FOBO will placed on a flat surface. By inspection, micro FOBO has two legs. L1-3 Inspection
4 Having a 3DOT board and/or Sparkfun Pro Micro 3.3v/8Mhz A 3DOT board and/or Sparkfun Pro Micro 3.3V/8MHz is present L1-6 Inspection
5 Place FOBO and micro FOBO side by side and take measurements Micro FOBO is smaller by 63% less  than original FOBO L1-10 Inspection/Analysis
6 A printable circuit is placed on the table counter. A printable circuit board is present L1-18 Inspection
7 A completely built micro FOBO is on the table. The micro servos on the FOBO are to be counted. Eight micro servos are present in the micro FOBO L2-3 Inspection
8 A UV sensor is placed on the counter table. Upon inspecting, there is UV sensor present. L2-4 Inspection
9 Measure the battery with a voltmeter and determine the volts of the battery. A battery that outputs 3.7V is present and helps function micro FOBO L2-6 Inspection/Analysis
10 Inspecting a completed micro FOBO, two LEDs will be on the head chassis. These LEDs will show that the micro FOBO is on. Two LEDs are on the head chassis turn on indicating that the micro FOBO is on. L2-11

 

 Inspection
11 A completed micro FOBO will be measured with a ruler. Measurements will be noted. Micro FOBO measurements are 4.5” x 3.25” x 7.25” (l x w x h) L2-14 Inspection/Analysis
12 A completed micro FOBO weight will be measured on a scale. And Micro FOBO does not exceed a total weight of 460 grams. L2-15 Inspection/Analysis

TC-03: Functionality of Micro FOBO

Detailed Description

The goal of this test case is to demonstrate the functionality of micro FOBO. this is test case describes the creation, construction, and completion of micro FOBO. For each aspect of creation construction, and completion provides certain conditions of how micro FOBO is physically done. It is going from the step of being 3D printed to assembling it together to being completed.

Test Case Traceability and Pass/Fail Matrix

This matrix shall show all requirements that are being tested in this test case. The Pass/Fail Column is populated after the Test Case has been run via the Procedure Steps.

Requirement Number Requirement Text Verification Success Criteria Verification Method (Test, Analysis, Demonstration, Inspection) Pass/Fail
L1-11 Micro FOBO shall detect intersections of the maze. Micro FOBO detects intersections of the maze. Inspection Fail
L1-12 Micro FOBO shall be able to perform static walking Micro FOBO performs static walking Inspection Fail
L1-13 Micro FOBO shall produce a 90-degree turn. Micro FOBO turns at 90-degree turn Inspection Fail
L1-14 The user shall guide the Micro FOBO through the maze with the use of the Arxterra application. The user guides the Micro FOBO through the maze using the Arxterra application Inspection Fail
L1-15 Micro FOBO shall record the path of the maze Micro FOBO records the path of the maze Inspection Fail
L1-16 Micro FOBO shall traverse the maze using the recorded path. Micro FOBO traverses the maze using the recorded path Inspection Fail
L1-21 Micro FOBO should be able to perform dynamic walking. Micro FOBO performs dynamic walking Inspection Fail
L2-1 Micro FOBO will be connected via Bluetooth to the app on an android phone Micro FOBO connects via Bluetooth using an android phone Inspection Fail
L2-5 By detecting the colors of the maze, the Micro FOBO shall determine if it is at an intersection. (intersection detection) Using the colors of the maze, Micro FOBO detects an intersection Inspection Fail
L2-7 The user shall use the Arxterra application to move the robot forward, left, and right. Micro FOBO moves forward, left and right. Inspection/Analysis

 

 Fail
L2-12 Micro FOBO shall record the path of the maze the Micro FOBO traverses on the 3DoT board or the Sparkfun Pro Micro 3.3V/8MHz to navigate the robot through the maze. Micro FOBO records the path of the maze and navigates micro FOBO through the maze. Demonstration Fail
L2-16 Micro FOBO shall detect objects 8 inches from it. Micro FOBO detects an object 8 inches from it Inspection Fail
L2-17 Micro FOBO should be able detect other robots and avoid collision. Micro FOBO should stop completely and wait for command Micro FOBO detects other robots in the maze and stops. It stops and awaits command. Demonstration Fail

Detailed Success Criteria

The success of this test case will show the functionality of micro FOBO. These functions of micro FOBO will help it traverse the maze. These are different than the ones from test case 4 as in these functions are required to walk the maze. These test cases are what is required for the group project.

Test Environment

This test case will be taking place in ECS 316.

Assumptions and Preconditions

  • Previous two test cases are completed.
  • The code is running properly.
  • Parts are functioning properly.

Procedure Steps

Step Number Step Description Pass Criteria Recorded Data Requirement(s) Tested Test Method
1 While micro FOBO is walking in the maze, it will use its UV sensor to Micro FOBO detects an intersection in the maze. A value is recorded L1-11 Demonstration
2 A functional micro FOBO will be placed on the table counter. The code for micro FOBO will be Micro FOBO is able to static walk L1-12 Demonstration
3 While the micro FOBO is running, the micro FOBO will attempt to turn. A 90-degree turn is produced while it is attempting to turn. L1-13 Demonstration
4 While the user is connected to the micro FOBO, the user should be able to guide micro FOBO through the maze. The user is able to guide micro through the maze. L1-14 Demonstration
5 While traversing the maze, micro FOBO records the maze. Micro FOBO records the path of the maze it took. L1-15 Demonstration
6 Using the recorded path of the maze, micro FOBO will traverse this path Micro FOBO traverses the record path. L1-16 Demonstration
7 While micro FOBO is walking, a dynamic can be inspected. Micro FOBO dynamic walks. L1-21 Demonstration
8 Using the Arxterra application, micro FOBO will be connected via Bluetooth. Micro FOBO is connected via Bluetooth L2-1 Demonstration
9 Micro FOBO will be on the maze, walking. While walking, micro FOBO will detect the colors of the lines. And it will determine whether if its at an intersection While on the maze, micro FOBO detects the colors on the maze. Based on the colors of the maze, it will determine if it is at an intersection. L2-5 Demonstration
10 Once micro FOBO is connected to the Arxterra app, the user will demonstrate the functions of walking forward, turning left and right. The user is able to make micro FOBO walk forward, turn left and right. L2-7 Demonstration
11 Micro FOBO will record the path it takes on the 3DOT board or the Sparkfun Pro Micro 3.3V/8MHz to navigate the robot through the maze. Micro FOBO records the path of the maze  on the 3DOT board or the Sparkfun Pro Micro 3.3V/8MHz and navigates it throught the maze. L2-12 Demonstration
12 Micro FOBO will be placed on the table. The program for micro FOBO will be running and the ultra sonic sensor will detect objects 8 inches away. Micro FOBO detects objects 8 inches from it. L2-16 Demonstration
13 While in the maze, micro FOBO will detect other robots on the maze and avoids collision. It will stop and await command. Micro FOBO detects other robots in the maze and stops to avoid collision. It then stops and awaits command. L2-17 Demonstration

TC-04: Micro FOBO’s Extra Functionality and Challenges

Detailed Description

This test case will demonstrate any extra functionality and challenges for micro FOBO. The requirements for this test case are should and shalls for micro FOBO. These extra things that are not required for the basic functionality of micro FOBO but the extra features and challenges that we wanted to demonstrate for micro FOBO. These extra functionalities include playing a musical tune and/or taking a bow at the end of maze. These are extra functions to demonstrate some creativity that micro FOBO can perform.

Test Case Traceability and Pass/Fail Matrix

This matrix shall show all requirements that are being tested in this test case. The Pass/Fail Column is populated after the Test Case has been run via the Procedure Steps.

Requirement Number Requirement Text Verification Success Criteria Verification Method (Test, Analysis, Demonstration, Inspection) Pass/Fail
L1-17 Micro FOBO shall traverse cloth, paper, and linoleum. Micro FOBO walks on cloth, paper, and linoleum. Inspection Fail
L1-20 Micro FOBO should step over a square rod 1cm tall by 1cm wide by 10 cm long Micro FOBO steps over a square rod of 1cm tall by 1cm wide by 10cm long. Inspection Fail
L2-10 Micro FOBO shall play a musical tune when the maze is completed Micro FOBO plays a musical tun when the maze is completed. Inspection Fail
L2-18 Micro FOBO should take a bow at the end of the maze. Micro FOBO takes a bow at the end of the maze. Inspection Fail

Detailed Success Criteria

This test is successful if micro FOBO performs any of the extra functions or challenges. These requirements were to demonstrate some creativity of micro FOBO.

Test Environment

This test case will be taking place in ECS 316.

Assumptions and Preconditions

  • Micro FOBO test case 1 through 4 functions properly.

Procedure Steps

Step Number Step Description Pass Criteria Recorded Data Requirement(s) Tested Test Method
1 Micro FOBO will placed in different terrain fields such as cloth, paper and linoleum and it will walk  on those terrain fields Micro FOBO is able to traverse cloth, paper, and linoleum. L1-17 Demonstration
2 The square rod measuring 1cm tall by 1cm wide by 10cm long is placed on the table. Micro FOBO will walk toward the square rod Micro FOBO steps over a square rod mearsuring 1cm tall by 1cm wide by 10cm long. L1-20 Demonstration
3 Micro FOBO  traverses a path of the maze. It will finish the maze. Once micro FOBO completes the maze, a musical tune plays to show that it finished maze. L2-10 Demonstration
4 Micro FOBO traverses a path of the maze and it will finish the maze. After the musical tune that is played when the micro FOBO finished the maze, micro FOBO takes a bow. L2-18 Demonstration

TC-05: Cost, Storage, Fitting in Maze Dimensions

Detailed Description

This test case describes the cost, the storage and the fitting in the maze for micro FOBO.

Test Case Traceability and Pass/Fail Matrix

This matrix shall show all requirements that are being tested in this test case. The Pass/Fail Column is populated after the Test Case has been run via the Procedure Steps.

Requirement Number Requirement Text Verification Success Criteria Verification Method (Test, Analysis, Demonstration, Inspection) Pass/Fail
L1-5 Micro FOBO will fit within the classroom cabinets. 28”x13”x14.5” Micro FOBO fits in the cabinet within those dimensions Inspection Pass
L1-9 Micro FOBO shall not exceed a cost of $250.00 to construct. Cost does not exceed $250.00 Inspection Pass
L2-2 Micro FOBO dimensions of robot will need to be small enough to fit in a 4in by 4in box for maze purposes. Micro FOBO fits in the 4in by 4in square of the maze. Inspection Pass

Detailed Success Criteria

This test case is successful if micro FOBO does not invalidate any of the requirements. Micro FOBO meets each of the requirements.

Test Environment

This test case will be taking place in ECS 316.

Assumptions and Preconditions

  • Micro FOBO is successfully built.

Procedure Steps

Step Number Step Description Pass Criteria Recorded Data Requirement(s) Tested Test Method
1 Carry micro FOBO to the cabinets and place it in one of the cabinets. Micro FOBO fits in the cabinet within those dimensions L1-5 Demonstration
2 View the cost report for micro FOBO and review the total cost. Micro FOBO’s cost does not exceed $250.00 L1-9 Inspection/Analysis.
3 Micro FOBO will be placed in one of maze squares. Micro fits inside of the 4in by 4in maze squares. L2-2 Inspection/Demonstration

Appendices

This section will contain any additional documentation needed to verify/validate requirements. For example, if a project has a cost constraint requirement, include the cost breakdown spreadsheet below as a subsection and reference the appendix subsection in the related Test Step in the Test Procedure. If another group needs to verify something by hand via calculation, include the calculations as a subsection below and reference the appendix subsection in the related Test Step in the Test Procedure.

  1. Print Time of FOBO
  2. Mass Report

Spring 2018: BiPed 3D Print Time

/in /by

Written By: Miguel Gonzalez (Project Manager and Manufacturing)

Approved By: Miguel Garcia (Quality Assurance)

Update: 3D Printing Time Waiver (Approved on 5/01/2018)

Introduction

In this blog post, we will cover the overall 3D print time for the complete assembly of the Mirco FOBO. The Micro FOBO’s design is based on the original FOBO which was created by Jonathan Dowdall but utilizes updated and revised components. The design of the components will not be mention in this post but can be found in our Mechanical Design blog post. This post will explore the time it takes to manufacture parts for the Micro FOBO using a 3D printer. To better calculate the amount of time, use for fabrication I have created a table listing all the parts that are needed to assemble our robot and listed the time it takes to make it. Micro FOBO uses a total of fifteen 3D printed pieces which takes seven hours and forty-eight minutes. It is important to note that our current printing time violates our customer’s program requirement of keeping the printing time under 6 hours total. Only the head of FOBO exceeds the 2-hour limit of 3D printing requirement per part. Due to this violation, we have decided to appeal this requirement with a waiver document. By getting the approval of the customer through this appeal we won’t need to make any changes to our design or 3D printing process.

Related Requirements

Level 1 Requirements:

L1-8: Micro FOBO’s part components will be 3D printed using the material carbon fiber PLA.

L1-9: Micro FOBO will not exceed a print time of 7.80 hours. Upon approval of the waiver.

Level 2 Requirements:

L2-2: Micro FOBO dimensions will need to be small enough to fit in a 4in by 4in box for maze purposes.

L2-15: Micro FOBO shall weigh no more than the allocated mass of 460g.

Fig.1 Printing Times on Simplify3D

Table Data:

The table above shows Micro FOBO’s parts listed with their own “Build Statistics” which is information about the part’s printing time, weight, and cost of materials. This information was gathered through the slicing software, Simplify3D. All parts were listed to have a layer height of 0.20mm and 25% infill when producing the printing time information.

Final Remarks

It is important to note that the printing time shown above has been completely processed via slicing software but has been verified to be correct when printing the first full prototype. All 3D printing is done through my own 3D printer but the material (Carbon Fiber PLA) bought will be processed for reimbursement. As mentioned before, we currently exceed the amount of time allocated by the customer for printing time. The main reason we cross the six-hour mark is due to the head of FOBO requiring large amounts of support material and thus requiring more time to print out. We hope that the customer accepts our printing time waiver to allow us to keep the same head design and printing process.

References

Spring 2018: Micro FOBO Mechanical Designs

Spring 2018: Testing Design Sketches

/in /by

Written By: Miguel Gonzalez (Project Manager and Manufacturing Engineer)

Approved By: Miguel Garcia (Quality Assurance)

Table of Contents

Related Requirements

Level 1 Requirements

L1-3: Micro FOBO will have 2 legs.

L1-4: Micro FOBO will be a toy robot based on the design of the FOBO by Jonathan Dowdall.

L1-8: Micro FOBO’s part components will be 3D printed using the material carbon fiber PLA.

L1-11: Micro FOBO shall be 60% or less of the overall size of Jonathan Dowdall’s FOBO

Level 2 Requirements

L2-2: Micro FOBO dimensions will need to be small enough to fit in a 4in by 4in box for maze purposes.

L2-3: Micro FOBO will use SG90 micro servos.

Customer Requirements

C-03: The robot will be designed to be a toy for people ages 8+.

C-04: In order to minimize manufacturing cost, and packaging cost the robot shall be able to be constructed from sub assemblies within 10 minutes.

Before CAD

One of the first things we did when verifying our sketches was produced a copy of the original FOBO from www.projectbiped.com this would help in determining correct aspect ratios for the creation of the Micro FOBO. Using parts from previous semesters we managed to get all the necessary components to produce the FOBO. We 3D printed the parts for FOBO and assembled it all within the first three weeks of the semester.

Fig.1 Original FOBO Source: projectbiped.com

Fig.2 Printed FOBO

 

 

 

 

 

 

 

 

 

 

 

By using the printed out FOBO I was able to measure the individual parts of the robot and produce a scaled down version of each part. It mainly relied on using ratios of the larger servos compared to the micro servos our group planned on using. Figure 2 is an image that was taken after the testing of the micro FOBO parts but is a good illustration of the size comparison between the original  FOBO (in blue) and the Micro FOBO (in black).

Creating the 3D Models

After creating the Initial Design Drawings on paper I made sure to 3D model the parts on Solid Works and test how the parts fitted together. Typically we can verify how the parts work together by using Solid Works Assembly and verifying the dimensions allow the parts to fit onto the micro servos and with one another. Of course, all parts first needed to be designed before we can verify part compatibility this also included designing the micro servos, ultrasonic sensor, and custom PCB. Below you will find 3D models of parts and components that were designed in Solid Works CAD.

Fig.3 3D Model of Micro Servos

Once all the parts were 3D modeled the first compatibility test on the parts was conducted by assembling all parts together using Solid Works. This process involved virtually assembling the Micro FOBO and verifying that all parts fit together properly and that all mounting holes aligned with each other.

Fig.4 Micro FOBO Exploded Assembly

Fig.5 Micro FOBO Full Assembly

 

 

 

 

 

 

Testing the 3D Models

The last thing to do was to 3D print a prototype of the Micro FOBO and verify the results obtained from the assembly. Most parts that were printed out needed no revisions. Only the servo band and servo bracket required revisions. These parts typically required revising the mounting holes for the micro servos and slightly increasing the holes where the wires fitted through. Once the changes were applied to the model the parts were 3D printed again and verified that the issues no longer remained. We tested all designed parts by assembling a full-scale working prototype as shown below.

Fig.6 Part Verification

Fig.7 Testing Servo Fitting

 

 

 

 

 

 

 

 

 

Fig. 8 Part Verification with Sketches

Fig.9 Assembly Process

Fig.10 Head Verification and Assembly

References

  1. www.projectbiped.com
  2. Initial Design Drawings

Spring 2018: BiPed Initial Design Sketches

/in /by

By: Miguel Gonzalez (Project Manager & Manufacturing)

Approved By: Miguel Garcia (Quality Assurance)

Related Requirements

Level One Requirements

L1-3: Micro FOBO will have 2 legs.

L1-4: Micro FOBO will be a toy robot based on the design of the FOBO by Jonathan Dowdall.

Level Two Requirements

L2-3: Micro FOBO will use SG90 micro servos.

L2-14: Micro FOBO shall measure within 4.5” x 3.25” x 7.25”.

Initial Sketches and Design

Since our robot was going to be based on the original FOBO created by Jonathan Dowdall we first needed to do some observation on his design. The original FOBO measured 24cm ( 9.5″) tall and 15.25cm ( 6″) wide. Because we are creating a miniature version of this design we can measure the servo size the original FOBO had with the micro servos we plan to use. As fig.1 shows, we can measure the two different servos and calculate their perspective ratio size with one another to give us an approximation of how small we can make our robot.

Fig.1 Calculating Ratio Sizes

Various ratios were calculated from the measurements of the two servos and we discovered that our micro version of FOBO will be approximately 60% scale of the original FOBO. This is quite a significant reduction. Now that we had our ratios and measurements of the servos we could begin by sketching some of the FOBO parts and incorporate them to suit our miniaturized robot. The servo band and servo bracket were one of the first parts to be sketched and design since these parts attached the servos onto the FOBO’s leg. Measurements from the servos and the servo horns make up the dimensions of these parts. Since the micro servos were designed to be pressure fitted onto some of the parts small tolerances where only acceptable. It was made sure to only use datasheet measurements with verified dimensions from caliper measurements.

Fig.2 Sketches of Bearing Frame and Servo Wrap

Fig.3 Body Riser Sketches

Many of the initial sketches have inaccuracies in their stated dimensions, this is due to the fact that testing and fast prototyping is needed to verify that the pieces would fit together. When designing the head of the robot it became evident that simply reducing its size by 60 percent of the original FOBO will not be sufficient. The head of micro FOBO is reliant on the size of the 3DoT board and the shield that will be mounted on it. Rough estimates on the dimension of the controller board were guessed in order to begin an initial sketching of the robot’s head. Once the head had been sketched it became evident that we can do some designs on its face to better meet the robot’s requirement of looking like a toy. This meant that we could use the ultrasonic sensors to look like eyes and thus we can design a nose and mouth to finish the face features. Antennas were also sketched on the head of the robot to simulate how toy robots looked like in the 1950s.

Fig.4 Head Sketches

Fig.5 Full Body Sketch

References

  1. http://www.projectbiped.com/prototypes/fobo
  2. 1950s Robot Toys

Spring 2018: BiPed Ultrasonic Sensor Board & Prototype Fritzing Diagram for BiPed

/in /by

By: Jorge Hernandez (Electronics & Control Engineer)

Verified By: Miguel Gonzalez (Project Manager)

Approved By: Miguel Garcia (Quality Assurance)

Table of Contents

Introduction

From the research performed, the number of ultrasonic sensors required to make a biped
robot is one sensor. We know one sensor will be used which will cause the robot to only
detect objects in a one-directional plane. According to our level 2 requirements, we are using
the ultrasonic HC-SR04 sensor to meet out level two requirements:
Shall be able to see other robots to avoid a collision. The robot will stop completely and wait for
a command. (Ultrasonic sensor). This expands farther:
1. If the sensors are too far from an object, the robot will move forward.
2. If the sensors are too close to an object, the robot should move backward.
3. If the sensors are within the range of an object, the robot will not move.

Types of Ultrasonic sensors

Ultrasonic sensors have a range of 2-450cm (0.78-177in) which will be suitable to track the
other robots from 20 inches away. The way ultrasonic sensors operate is through emitting
sound waves and detecting the sound reflected back from the object. From the reflected
sound, the sensor can provide a measurement of how far an object is away from it. The pros of
ultrasonic sensors are that they can detect objects from farther distances and they can detect
small objects accurately. Also, they can operate in harsh conditions such as dirt. However, they
have slower response times than other sensors, their measurements can be distorted by loud
noises, and surfaces that absorb sound can deter their measurements. The dual cylinder
HC-SR04 is powered up through a 5V source, which will be suitable for our application because
we are using a 5V source coming through the I2C pins of the 3DoT board. The single cylinder
MaxSonar EZ1 Sensor can be powered through a 3V source, which will not be compatible with
our project. This makes the HC-SR04 Sensor the ideal ultrasonic sensor to use in our application.

Prototype Fritzing Diagram for BiPed:

The Fritzing application allows a physical breadboard design to be created digitally. By designing
a digital version, the beginning PCB designs can begin. One difficulty with using the free
software is that the library does not have all the parts needed for many designs. Using Google,
many of the parts required were found with Github.
Here are links to the Fritzing libraries for FOBO:
(If using the Adafruit Servo Driver)
(For the Bluetooth Module HC-06 and Accelerometer/Gyroscope MPU-6050)

Fig.1 Electronic Fritzing Diagram

 

There was nothing to change at all as we are using the FOBO’s same hardware build. We decided
to go with 2 Lithium Ion batteries, 12 servos, and ultrasonic as well. The color sensor is being
discussed since we know Spiderbot wants to use UV sensors but will be added to fritz diagram
once we know the final maze descriptions.

References

Spring 2016 RoFi: Finalized Fritzing Diagram, PCB Design, Alternative Arduinos, and Custom Eagle Components

Tracking Sensors Trade Off Study

Updated Here: Blog Post

Spring 2018: BiPed Power Estimates of Components: Micro Servos

/in /by

By: Jorge Hernandez (Electronics & Control Engineer)

Verified By: Miguel Gonzalez (Project Manager)

Approved By: Miguel Garcia (Quality Assurance)

Table of Contents

Power Estimates 

For power estimates I calculated power and current on two types of servos; the Tower Pro SG90 and metal geared MG90s. To read the power and current from the servos on different loads, I used the INA219 current sensor. A 3-D pully was made and connected on top of the servos as Professor Hill suggested.

Fig.1 Testing Environment

Coding

I combined the Sweep Arduino code with an Arduino code to read the current and power from the INA219 current sensor. I used a function ‘read values’ to act as the INA219 sensor and embedded it within the for loop which had the servo turn back and forth 180 degrees which are known as the sweep code for servos. Here it will read the values every 5 degrees to get an accurate reading. 

/* Sweep

 by BARRAGAN <http://barraganstudio.com>

 This example code is in the public domain.

 modified 8 Nov 2013

 by Scott Fitzgerald

 http://www.arduino.cc/en/Tutorial/Sweep

*/

#include <Servo.h>

#include <Wire.h>

#include <Adafruit_INA219.h> // You will need to download this library

Adafruit_INA219 sensor219; // Declare and instance of INA219

Servo myservo;  // create servo object to control a servo

// twelve servo objects can be created on most boards

int pos = 0;    // variable to store the servo position




void setup() {

  myservo.attach(9);  // attaches the servo on pin 9 to the servo object

  Serial.begin(9600);    

  sensor219.begin();

}

void ReadValues ()

{

   float busVoltage = 0;

  float current = 0; // Measure in milli amps

  float power = 0;

  busVoltage = sensor219.getBusVoltage_V();

  current = sensor219.getCurrent_mA();

  power = busVoltage * (current/1000); // Calculate the Power

//  Serial.print("Bus Voltage:   "); 

//  Serial.print(busVoltage); 

//  Serial.println(" V");  

  Serial.print("Current:       "); 

  Serial.print(current); 

  Serial.println(" mA");

  Serial.print("Power:         "); 

  Serial.print(power); 

  Serial.println(" W");  

  Serial.println(""); 

  }

void loop() {

  for (pos = 0; pos <= 180; pos += 1) { // goes from 0 degrees to 180 degrees

    // in steps of 1 degree 

    if (pos%10==0)

    {

    ReadValues ();

    }

    myservo.write(pos);              // tell servo to go to position in variable 'pos'

    delay(15);                       // waits 15ms for the servo to reach the position

  }

  for (pos = 180; pos >= 0; pos -= 1) { // goes from 180 degrees to 0 degrees

    if (pos%10==0)

    {

    ReadValues ();

    }

    myservo.write(pos);              // tell servo to go to position in variable 'pos'

    delay(15);                       // waits 15ms for the servo to reach the position

  }

}

Results

Table 1: SG90(plastic Micro-servo) @ 3.3 V

Table 2: MG90 (metal Micro-servo) @ 3.3 V

Table 3: SG90(plastic Micro-servo) @ 5V

Table 4: MG90(metal Micro-servo) @ 5 V

Conclusion

SG90 Plastic Geared will be used for Micro Fobo as it satisfies more requirements than the MG90 metal geared micro servo. The SG90 also pulls less current at different loads.  Both micro servos operate at 3.3V (L2-7: Micro FOBO shall use a battery that outputs 3.7V) but as can be seen, the MG90 stalls with a load of 200 grams. Satisfies customer requirement as it is toy based and will have a cleaner look as they are small and fit well on the chassis.

References

  1. https://www.arxterra.com/spring-2016-velociraptor-servos/
  2. https://www.arxterra.com/servo-trade-off-study/

Spring 2018: BiPed Interface Matrix

/in /by

By: Jeffrey De La Cruz (Mission, Systems, and Test Engineer)

Verified By: Miguel Gonzalez (Project Manager)

Approved by: Miguel Garcia (Quality Assurance)

Fig.1 Interface Matrix

The current interface matrix for the prototype Micro FOBO uses the Arduino UNO. A CD4017BE IC was used in order to control the eight servos. The output of the CD4017BE IC was then connected to the Arduino UNO which will the Robot Poser control the movement of the servos so that the Micro FOBO can walk. The interface matrix will be updated once the 3DoT board or the Sparkfun Pro Micro 3.3V/MHz is acquired. This is currently for the prototype of the Micro FOBO.
The excel file containing the interface matrix for the prototype Micro FOBO can be found

Spring 2018: Interface and Cable Tree Blog Post

/in /by

By: Jorge Hernandez (Electronics & Control Engineer)

Verified By: Miguel Gonzalez (Project Manager)

Approved by: Miguel Garcia (Quality Assurance)

New and improved System Block Diagram for Micro Fobo which shows in a general diagram how many pins will be needed for each component and how they connect to each other. As seen we are using a total of 5 sensors, a custom PCB, Bluetooth module, external battery and of course a Pro Micro. This helps a lot for our E&C engineer when it comes to PCB designing as they need to plan accordingly.

Fig.1 Micro FOBO System Block Diagram

Wiring Management

No Exposed Wires;

Wiring for sensors, Pro Micro, and PCB will not be exposed and will all be within the head of Micro Fobo.

Exposed Wires:

1/8 Inch PET Expandable Braided Sleeving with quarter inch heat shrink tubing will be used on the wires that connect the micro servos to the header

  • Used to cover the wires of the SG90 micro servo
  • Ensures complete coverage and protection of wires
  • Clean design

The cables for the servos are routed out of the head encasement and directly to the servos through the back of Micro Fobo. Below is a photo of how clean Micro Fobo will look.

Fig.2 Micro FOBO full Assembly

References

  1. https://www.arxterra.com/spring-2017-spiderbot-cable-tree-design/