BATTERY TRADE-OFF UPDATE

By Brian Walton (Manufacturing Engineer)
Approved by Paul Oo (Project Manager)
Approved by Railly Mateo (Systems Engineer)

Item	Voltage	Amphours	Rating	Quantity	Price Per Qty
Dynamite LiPo Battery DYN 1419	7.4 V	2000 mAh	5C	1	$29.95
Lithium Ion Polymer Battery	3.7 V	2500 mAh	1C	2	$14.95
9V Battery	9V	120-1200mAh		1	$2+

The table above compares 3 possible batteries to use for the µBiPed project. The table compares supplied voltage, Amphours, rating, quantity, and price per quantity. The 3 batteries shown here on the table were chosen based off the updated mass and power reports.

Conclusion:
In the end we went with the Dynamite LiPo battery for multiple reasons:

1. The price per quantity was negligible between the 7.4 and the 2 3.7 V batteries.
2. While the 9V battery was cheaper short term, having rechargeable batteries are cheaper long term.
   1. Additionally this project being the feasibility demonstration of a toy, it’ll be better to have the toy already designed for rechargeable batteries.
3. Even though the Lithium Ion had better rating for Amphours, the Dynamite Pro can handle better surges.

BATTERY TRADE-OFF

By Michael Balagtas (Manufacturing Engineer)
Approved by Paul Oo (Project Manager)
Approved by Railly Mateo (Systems Engineer)

Picking a battery with our level one requirements (Toy, compact, cheap) brings many conflicts to our final decision, so a trade-off study will be done between a generic 9V battery, two 3.7 LiPo batteries, and a Powerex Imedion AA batteries.

Our overall mission is very simple: climb up a short incline and come back down in a figure eight. At worst, the mission will take no longer than 10 minutes, and that is assuming that the robot will shuffle due to lack of traction. However, we still need to compensate for our large current requirements. The eight servos to be used have a current draw of about 150mAh each and the Arduino Micro has about 100mAh, putting our overall current budget to about 1.4Ah. Considering the mission duration, we can take some liberties with this amount and set our goal to about 300-400mAh. The characteristic curves of the batteries will be ignored to simplify this process.

Manufacturer	Material	Voltage	Quantity	Current Rating	Dimensions	Volume	Price
Energizer	Alkaline	9V	2	230mAh	46.4mm x 24.5mm x 15.5mm	17620mm3	$12.00
Syma	Li-Po	3.7V	3	500mAh	42mm x 25mm x 9mm	9450mm3	$8.95
Imedion	Ni-MH	1.2V	4	2400mAh	N/A	N/A	$10.95

The table above compares 3 possible batteries to use for the µBiPed project. The table compares material, supplied voltage, quantity, current rating, dimension, volume, and price. After comparing the 3 batteries, we realized that the project needed to pushed further into manufacturing before we could decide which battery to choose.

Considering that the device is marketed as a toy, safety and choking hazards are a priority, therefore Lithium Ion is out of the picture, leaving us with the above options. At first glance, it looks as if the Imedion would be a landslide decision because of its current rating, but that’s too much for our mission parameters. To narrow down our decision, we will conduct a few studies: size, operational time, and price.

As a toy, cheap power sources is a requirement for easy access to power off the shelf. By and large, the Syma Li-Po wins over every other choice

We want the biped to be as small and as light as possible, so the smallest and lightest battery is the most desirable. However, the number of batteries is also taken into account. The Energizer only requires one battery to operate properly, whereas the Li-Po requires two and the Imedion requires four. The Syma Li-po would be comparable to that of a 9V battery once stacked together but they’re also light; the Imedion is tempting but there was no data for the batteries. As for right now, this study is a stalemate.

The last and most controversial of the above parameters is the current rating, because the current rating can change based on the current draw. Therefore, to streamline the process, it is assumed that these are ideal. The Imedion easily overpowers everyone else in this department because of its 2400mAh rating, but that is due to its unloaded nature. Nevertheless, we will assume that it takes the edge here

Conclusion: Either the Syam Li-Po or the Imedion will be utilized. The decision is heavily leaning towards the Syam because of the mass and given data.

MISSION PROFILE & PROJECT OBJECTIVE UPDATE

By Paul Oo (Project Manager)
Approved by Paul Oo (Project Manager)
Approved by Railly Mateo (Systems Engineer)

After presenting the Project Design Requirements, the team met up with the President and Vice President to analyze the current status of the project. Realizing that creating a fully-functioning toy (that has to be spec’d for strict governmental standards such as remote control safety requirements) is not feasible for our allotted time to complete the project, the President suggested we change our mission profile and project objective to a feasibility demonstration.

Current Mission Profile & Project Objective:

Fall 2015 MicroBiPed (μBiPed) is inspired by the BiPed designed by Jonathan Dowdall of Project BiPed. The profile for this semester’s project is to use the BiPed & μBiPed designs to create a toy robot. The chosen design for a BiPed toy is a Tyrannosaurus Rex. To push the profile towards a feasibility demonstration requires a large emphasis on performance and budget. The objective of this project is to complete an obstacle course whilst controlled and communicating with the Arxterra™ Android application.    

Previous Mission Objective:

Fall 2015 MicroBiPed (μBiPed) is inspired by the BiPed designed by Jonathan Dowdall of Project BiPed. The objective for this year’s project is to use the BiPed & μBiPed designs to prototype a toy robot that resembles a Velociraptor. To push the objective towards prototyping a toy requires a large emphasis on cost. Although the mission is yet to be determined, the μBiPed must be controlled and be able to communicate with the Arxterra™ Android application.    

 

WORK BREAKDOWN STRUCTURE 
(Team Members Schedule)

By Paul Oo (Project Manager)
Approved by Paul Oo (Project Manager)
Approved by Railly Mateo (Systems Engineer)

Table 1 – Project Manager

Operation	Duration	Start	Finish	Resource Name
Project μBiPed	162 days	8/31/15	12/10/15	Paul Oo
Project Management	155 days	9/10/15	12/10/15	Paul Oo
Mission Objective	21 days	9/10/15	10/1/15	Paul Oo
Program Req.	21 days	9/10/15	10/1/15	Paul Oo
Work Allocation	21 days	9/10/15	10/1/15	Paul Oo
PDD	8 days	9/23/15	10/1/15	Paul Oo
PDR	7 days	10/1/15	10/8/15	Paul Oo
CDD	21 days	10/8/15	10/29/15	Paul Oo
CDR	7 days	10/29/15	11/5/15	Paul Oo
Documentation	168 days	8/24/15	12/9/15	Paul Oo
Final Presentation	35 days	11/5/15	12/10/15	Paul Oo
Project Video	70 days	10/1/15	12/10/15	Paul Oo

The table above (Table 1) shows the schedule created for the Project Manager. This schedule has been made to fit Fall 2015’s 400 D timeline and milestones. Furthermore, the schedule has been broken down according to program tasks (Mission Objective, Work Allocation, & Documentation). To improve this schedule, along with other members’, project managers should view this document from the first day of being assigned to their position.

Table 2 – Systems Engineer

Operation	Duration	Start	Finish	Resource Name
Systems Engineering	155 days	9/10/15	12/10/15	Railly Mateo
Project & Level 2 Req	13 days	9/10/15	9/23/15	Railly Mateo
System Block Diag.	8 days	9/23/15	10/1/15	Railly Mateo
Instructions Pamphlet	8 days	10/8/15	10/15/15	Railly Mateo
Hardware	14 days	9/23/15	10/7/15	Railly Mateo
Fritzing – System	8 days	9/23/15	10/7/15	Railly Mateo
Interface Design	2 days	10/6/15	10/7/15	Railly Mateo
Software	34 days	9/17/15	10/21/15	Railly Mateo
Arduino IDE	14 days	9/17/15	10/1/15	Railly Mateo
Bluetooth	4 days	10/8/15	10/11/15	Railly Mateo
Arxterra App	10 days	10/11/15	10/21/15	Railly Mateo
Testing	70 days	10/1/15	12/9/15	Railly Mateo
Subsystem/Syst. TP	70 days	10/1/15	12/9/15	Railly Mateo

The table above (Table 2) shows the schedule created for the Systems Engineer. The schedule has been broken down according to project tasks (Project & Level 2 Requirements, Hardware, Software, & Testing). To improve this schedule, along with other members’, system engineers should view this document from the first day of being assigned to their position. Systems engineers must be able to provide startup/error support to any subsystem.

Table 3 – Manufacturing Engineer

Operation	Duration	Start	Finish	Resource Name
Manufacturing	155 days	9/10/15	12/10/15	Michael Balagtas
Subsystem & L 2 Req.	13 days	9/10/15	9/23/15	Michael Balagtas
Design	14 days	9/23/15	10/7/15	Michael Balagtas
AutoCAD 3D Model	21 days	9/23/15	10/15/15	Michael Balagtas
EagleCAD High Level	2 days	10/6/15	10/7/15	Michael Balagtas
Production	44 days	10/1/15	11/15/15	Michael Balagtas
Fast-Prototype	15 days	10/1/15	10/15/15	Michael Balagtas
CNC Structure	8 days	10/15/15	10/22/15	Michael Balagtas
PCB Circuit board	38 days	10/8/15	11/15/15	Michael Balagtas
Testing	70 days	10/1/15	12/9/15	Michael Balagtas
Structure	70 days	10/1/15	12/9/15	Michael Balagtas
Electronics	70 days	10/1/15	12/9/15	Michael Balagtas

The table above (Table 3) shows the schedule created for the Manufacturing Engineer. The schedule has been broken down according to project tasks (Subsystem & Level 2 Requirements, Design, Production, & Testing). To improve this schedule, along with other members’, manufacturing engineers should view this document from the first day of being assigned to their position. Systems engineers must be able to provide startup/error support to any subsystem. In return, the subsystem engineers must be able to effectively produce level 2 requirements that meets project requirements.

Table 4 – Controls Engineer

Operation	Duration	Start	Finish	Resource Name
Controls & Process	155 days	9/10/15	12/10/15	Brian Walton
Subsystem & L 2 Req.	13 days	9/10/15	9/23/15	Brian Walton
Performance	21 days	9/23/15	10/15/15	Brian Walton
Arduino IDE Code	21 days	9/23/15	10/15/15	Brian Walton
EagleCAD Low Level	2 days	10/6/15	10/7/15	Brian Walton
Troubleshoot	37 days	10/7/15	11/15/15	Brian Walton
LTSPICE Simulations	37 days	10/7/15	11/15/15	Brian Walton
PID Control	37 days	10/7/15	11/15/15	Brian Walton
Testing	70 days	10/1/15	12/9/15	Brian Walton
Structure	70 days	10/1/15	12/9/15	Brian Walton
Electronics	70 days	10/1/15	12/9/15	Brian Walton

The table above (Table 4) shows the schedule created for the Controls Engineer. The schedule has been broken down according to project tasks (Subsystem & Level 2 Requirements, Performance, Troubleshoot, & Testing). To improve this schedule, along with other members’, controls engineers should view this document from the first day of being assigned to their position. Systems engineers must be able to provide startup/error support to any subsystem. In return, the subsystem engineers must be able to effectively produce level 2 requirements that meets project requirements.

PRELIMINARY DESIGN DOCUMENTATION

Paul Oo (Project Manager)
Michael Balagtas (Manufacturing Engineer)
Railly Mateo (Systems Engineer)
Brian Walton (Controls Engineer)

Mission Objective
Fall 2015 MicroBiPed (μBiPed) is inspired by the BiPed designed by Jonathan Dowdall of Project BiPed. The objective for this year’s project is to use the BiPed & μBiPed designs to prototype a toy robot that resembles a Velociraptor. To push the objective towards prototyping a toy requires a large emphasis on cost. Although the mission is yet to be determined, the μBiPed must be controlled and be able to communicate with the Arxterra™ Android application.

Requirements & Verification
Level 1 – Program Requirements

1. According to the CSULB Fall 2014 Academic Calendar, the μBiPed robot shall be tested by December 10, 2015; the date of the last day of 400 D.
   1. Verification: https://web.csulb.edu/depts/enrollment/registration/final_exam/fall_chart.html
2. According to 2014-2015 ARXTERRA µBiPed’s parts list, the project shall cost no more than $400.00.
   1. Verification:
      http://arxterra.com/final-documentation-microbiped/
3. To push the objective of the μBiPed towards the remote control toy industry, the lifetime & playtime shall be constrained to the mental development of a child 7-12 years old.
   1. Verification:
      https://www.cpsc.gov//PageFiles/113962/adg.pdf

Level 1 – Project Requirements

4. In accordance with the project name, the μBiPed shall travel on 2 legs.
   1. Verification:
      https://en.wikipedia.org/wiki/Bipedalism#Bipedal_robots
5. To be considered a miniaturized BiPed robot, the μBiPed shall range between 0.6 (120mm) ± 10% of Rofi’s dimensions according to the ratio of an MG92B μservo to Rofi’s servo.
   1. Verification:
      1. http://web.csulb.edu/~hill/ee400d/Project%20Folder/Robots%20and%20Drones/BiPed%20Robot/RoFi%20Project/ROFI%20CDR.pdf
      2. http://www.headsuphobby.com/Towerpro-14g-MG92B-Digital-Metal-Gear-High-Torque-SubMicro-Servo-A-537.htm
   2. In accordance with the obstacle course, the μBiPed shall walk up an incline that starts initially at 8° and then decreases to a 6° slope in relation to level ground.
      1. Verification:
         http://www.discountramps.com/wheelchair-ramp-length/a/B20/
   3. In accordance with the obstacle course, the μBiPed must walk over or on an object at about a 45° angle and a height of 2 cm.
      1. Verification:
         The μBiPed will walk over an object of about 2cm ± 1cm. The 1 cm is for margin of error. This will be measured by a ruler.
   4. In accordance with the obstacle course, the μBiPed shall walk on surfaces of varying friction coefficients:
      1. Carpet: 1.0 static [1]
         1. Verification:
            http://www.sciencedirect.com/science/article/pii/S187770581000367X
      2. Linoleum: 0.5 static [2]
         1. Verification:
            http://www.sciencedirect.com/science/article/pii/S187770581000367X
      3. Rubber: 1.0 static [3]
         1. Verification:
            http://www.sciencedirect.com/science/article/pii/S187770581000367X
      4. In accordance with customer specifications, the μBiPed shall communicate on Bluetooth -to an Android phone app.
         1. Verification:
            https://www.arxterra.com/final-documentation-microbiped/
      5. In accordance with customer specifications, the μBiPed shall have a payload that outputs a toy-like behavior.
         1. Verification:
            The current proposal for a payload is to use a cheap sensor that can react to certain changes in the environment.
      6. To follow toy safety regulations, the μBiPed shall comply with the federal toy safety standard, ASTM F963-11.
         1. Verification:
            http://www.cpsc.gov/en/Business–Manufacturing/Business-Education/Toy-Safety

Level 2 – System Requirements

1. According to CSULB 2015 Fall Finals Schedule, all subsystems shall stay within the time phasing to complete project μBiPed (by the due date of 12/10/15) and thus meet Level 1, requirement 1.
   1. Verification:
      The current task in the project schedule is planning. Along with the remaining tasks, (manufacturing, software integration, testing, and project video) the schedule will determine the allotted time for each phase of the project.
2. To have a realizable budget, the chassis shall be manufactured directly at CSULB and thus meet Level 1, requirement 2.
   1. Verification:
      3D printers and CNC machines are available at the behest of their respective departments.

3. To create a toy built for the attention span of a child between the ages of 7-12 years old, the μBiPed shall last 7-15 minutes and meet Level 1 requirement 3.
   1. Verification:
      To incorporate the mission objective of building a toy, the 4 AA batteries must be able to maintain system operations regarding the loads of chassis and 6 servos.

4. To facilitate all the algorithmic functions of a walking BiPed, the Arduino MICRO with an ATmega 32u4 Microcontroller will be used to meet Level 1, requirement 4.
   1. Verification:
      With the reduced amount of servos, the amount of PWM pins required are also reduced. Therefore the Arduino MICRO is the better choice in comparison to the Arduino UNO.

5. To maintain balance (while retaining core features of a BiPed), installment of a head & tail will be incorporated to the chassis to adjust the center of balance and thus meet Level 1, requirement 4.
   1. Verification:
      The reduced freedom of movement also means less ways to balance while moving. To compensate, alternative appendages can be attached to maintain the center of balance while moving.

6. To reduce the dimensions of the BiPed, the μBiPed shall use a two-servo to one-leg system to eliminate bulkiness and meet Level 1, requirement 5.
   1. Verification:
      The previous semesters utilized 6 servos per leg to increase the articulation, but increased the bulk, weight, and the height. A more mechanical approach will be used to control the legs to imitate a velociraptor model.

7. For the μBiPed to detect and adapt to inclines, a gyroscope shall be used to preserve chassis balance and meet Level 1, requirements 6 & 7.
   1. Verification:
      Level 1, requirement 6 & 7 indicates that the BiPed shall move up and down inclines. To adapt to such scenarios, the μBiped must be able to keep the body balanced by adapting to its relative center of gravity.

8. In regards to bluetooth communication with the Arxterra app, an IGT-3200 wireless adapter will be used to meet Level 1, requirement 9.
   1. Verification:
      To be controlled by an Android app, the machine must have a wireless adapter to enable wireless communication.

9. To adapt to different friction coefficients due to varying surfaces, an interchangeable shoe system will be used should the course terrain be changed..Level 1, requirement 8.
   1. Verification:
      This requirement is for flexibility in case linoleum tiles and carpet are no longer the terrain.

10. To produce a toy that complies with remote control safety regulations, the μBiped must be designed for the ages of 7-12 years old and thus meets Level 1, requirement 11.
    1. Verification:
       To create a remote controlled toy, the μBiPed must comply with US Consumer Product Safety Commission for age determination guidelines.
11. The μBiPed must avoid walls at a distance of (TBD). Determined by the mission profile. The distance may be determined based off of the constraints of the parts used to determine distance, or the customer may indicate distance.
    1. Verification:
       Will have the μBiPed walk towards an object, i.e. a wall, and see if the μBiPed will stop or try and change path. The distance will be measured with a tape measure.

DESIGN INNOVATION
Paul Oo (Project Manager)

Balanced Walking
Due to previous BiPeds using higher amount of servos for better articulation, the project has shifted towards having large legs/feet and heavy/bulky design. This year’s μBiPed design will be pushed towards prototyping a toy (specifically TITRUS III). This objective shall be the reference for system and subsystem designs.

Step 1. Brainstorm

• Finalized Balancing Attributes:
  • Type of Legs – Velociraptor (reverse joint)
  • Head – Purely payload (sensor)
  • Tail – Oppose head movement
  • Feet – Multipurpose (shoes)

Step 2. Lateral Thinking

• Finalized Forced Relationship:
  • Rubberband – Head and tail in opposing directions
  • Top – Gyro detects chassis orientation

Step 3. Solution  

• Design Conclusion
  To produce a toy-like design, the listed attributes must remain simple. By considering the design innovations of TITRUS III, the μBiPed will base its attributes on the concept of minimalism. Furthermore, the addition of shoes (for different terrains) will give customers incentive to invest into the product’s future developments.

ELECTRONIC SYSTEM DESIGN

System Block Diagram
This block diagram explains the system architecture of the μBiPed in regards to its connections. The μBiPed can be broken down into three main subsystems: inputs, outputs, and microcontroller. The inputs consists of an ultrasonic sensor (HC-SR04™), a gyroscope (TBD), and a bluetooth system (HC-06™). The outputs consists of 6 servo motors (MG92B). Finally, the microcontroller board consists of a battery and the Arduino Micro (ATmega 32u4).

Interface Definitions

1. Ultrasonic Sensor (HC-SR04^TM) – LED EYES
   1. The ultrasonic sensor will connect to 4 pins on the microcontroller for 5V power, ground, triggering, and echoing. It will be used to detect obstacles in the way of the robot and prevent the µBiPed from hitting the object.
   2. The reason for using an ultrasonic sensor is to possibly add a transducer to the sensor. Addition of the transducer will reduce the ultrasonic frequencies to a level that humans can hear. This audible sound is a toy feature.
2. Gyroscope (ITG-3200) – ORIENTATION
   1. The gyroscope will be attached to the SDA and SCL pins on the microcontroller. It will be used to detect the orientation of the µBiPed to allow the microcontroller to make balance-based corrections.
   2. The reason for using a gyroscope, rather than an accelerometer, is due to the multiples degrees of movement the legs will have to resemble a hip-based leg.
3. Bluetooth Device (HC-06^TM) – COMMUNICATION
   1. This Bluetooth device will be a slave to the microcontroller. It will be attached to the RX and TX pins of the microcontroller. The HC-06^TM will be used to communicate to an Android phone and receive commands from the Arxterra™ application.
   2. The reason for using a bluetooth system is based on customer specifications.
4. Microcontroller Board (Arduino Micro – ATmega 32u4) – Control
   1. The microprocessor must be cost efficient, small, and be able to use Dowdall’s code for the Arduino IDE.
      1. Requirements of the microprocessor:
         1. Dynamic memory or SRAM: 4.7 KB
         2. Flash memory: 14 KB
      2. Meeting these requirements are imperative for the μBiPed group because the variable initialization does not take up the most dynamic memory (only about 17% of the dynamic memory is used by the global variables). Map() function requires the most dynamic memory.

Fritzing Diagram

Michael Balagtas (Manufacturing)

Trade off studies

Railly Mateo (Computer Systems)

Servo comparison

Servo	Price  (1unit)	Torque	Speed	Weight	Dimensions
MG90S	$4.35	4.8V = 1.8kg/cm6.0V = 2.2kg/cm	4.8V = 0.10sec/60deg6.0V = 0.08sec/60deg	13.4 g	22.8 x 12.2 x 28.5mm
MG92B	$7.00	4.8V = 3.1kg/cm6.0V = 3.5kg/cm	4.8V = 0.15sec/60deg6.0V = 0.11sec/60deg	13.8 g	22.0 x 12.0 x 31.0mm
SG90	$4.31	4.8V = 1.0kg/cm	4.8V = 0.12sec/60deg	9.0 g	22.0 x 11.5 x 22.5mm

The above chart compares 3 possible servos to use for the µBiPed project. The chart compares torque, speed, weight, rotation, and price.

1. Torque is important because if the servos do not have enough torque the µBiPed will not move.
   1. Heavier servos means larger batteries.
   2. Slower servos means larger batteries due to a larger operation time to complete the course.
2. Speed and weight are important for the sizing of batteries.
3. Rotation is needs to 180 degrees to complete the required range of motion.
4. Pricing is a desired to lower the cost of the total budget.

After comparing the servos, the group decided on using MG92B for the purpose of having a higher torque rating.

1. Although MG90S and SG90 have less weight and lower cost than MG90S, they don’t have as much torque to move the µBiPed.
2. The MG92B is also a U.S. products and thus can be delivered much faster than other servos not listed in the chart.

Microcontroller comparison

Microcontroller	PWM Digital I/O pins	AnalogInputpins	Input Volt.	Dimension	Flash & SRAM	Price
Arduino MicroATmega32u4	6	6	7 – 12V	68.6 x 53.4 mm	32 kB & 2 kB	$22.00
Arduino UnoATmega328	7	12	7 – 12V	48 x 18 mm	32 kB & 2.5 kB	$25.00

The above chart compares 2 possible microcontrollers to use for the µBiPed project. The chart compares pins, input voltage, dimension, memory, and price.

1. The amount of pins available for analog and digital I/O’s are important because of the amount of sensors and servos the microcontroller will be connected to.
   1. We will need to connect 6 servos to analog pins on the microcontroller.
   2. We will need to connect 2 PWM pins to the payload.
2. Input Voltage is used for understanding the amount of voltage the batteries must supply.
3. The dimensions are key to creating a transparent embedded system.
4. Pricing is desired to lower the cost of the total budget.

After comparing the microcontrollers, the group decided on using the Arduino Micro for the purpose of having a smaller and most cost efficient microcontroller.

1. Although the Uno has more pins, our BiPed will need no more than 8 PWM pins for the servos.
2. The microprocessors are also differentiated as either through-hole or surface mount. Considering that the 32u4 is a surface mount microprocessor, it has the advantage in compact design.
3. Lastly, while the Uno has low margins for cost differentiation, the Micro ranges from $8.00 to $22.00. The difference in price is the main determinant for why the Arduino Micro was chosen.

Payload comparison – LiDar vs Ultrasonic Sensor – HC

SENSOR	Sain SmartHC-SR04	LIDAR-Litev2
POWER SUPPLY	5V	6V
WORKING CURRENT	15Ma	2Ma
DIMENSION	45mm x 20mm x 15mm	20mm x 48mm x 40mm
RESOLUTION	0.3 cm	1 cm
PRICE	$10.00	$115.00

 The above chart compares 2 possible payloads to use for the µBiPed project. The chart compares power supply, working current, dimensions, resolution, and price.

1. Determining the amount of power and current needed is important because the microcontroller has a limit of 5V output.
2. The dimensions are key to creating a transparent embedded system.
3. Resolution is also considered to determine which sensor can provide a better user interface performance.
4. Pricing is desired to lower the cost of the total budget.

After comparing the two sensors, the group decided on using the Ultrasonic Sensor for the purpose of having a more cost efficient payload.

1. Although Lidar-Lite has better resolution than the HC-SR04, the cost to purchase a single LIDAR overweights its positive trade-offs.

Rapid Prototyping
In order to test the µBiPed, the code from Dr. Dowdall will be uploaded onto an ATmega microcontroller but will be modified to control only six servos. The choice of six servos is to allow for the manipulation of one leg. The purpose is to experiment with leg motion. As the µBiPed is required to step over an object of a certain height, it is important to track the default motion of the leg. This means that if the default movement of the legs does not rise of the 2 cm height a modification to the code will have to be made in order to allow for the ability to walk over an object of 2 cm.

Interface Matrix
Brian Walton (Control & Image Processing)

 

Task Assignments
(Michael)

Michael Nico Balagtas

1. Construct physical models of the μBiPed for fast prototyping and error analysis.
2. Computer Aided Design(CAD)
   1. Mechanical- Use Solidworks or DesignSpark to draft preliminary designs for critical review.
   2. Electronic – Use EAGLE software to draft final PCB design for fabrication through a third party
3. Acquire information on how to use CSULB CNC machines or 3D printers for either metal or plastic builds.
4. Manufacture parts for final mechanical product using either metal or plastic materials.
5. Assemble final product through soldering and occasional post processing.

Railey Mateo

1. Will learn C++ programming language to code algorithms using the Arduino IDE.
2. Will work with Controls division member to optimize servos and gyroscopes.
3. Will browse through datasheets of equipment to locate the appropriate registers of the peripheral equipment.
4. Learn how to use IGT-3200 Wireless adapter.
5. Algorithms
   1. Modify frame capture code from Mr. Dowdall to accompany a new two servo design.
   2. Create state diagrams for the walking frames and the transitions from each frame to the next.
   3. Code complex algorithms to determine behavior of μBiPed when on or approaching inclined surfaces.
   4. Code algorithms to calibrate and read input from gyroscopes using I2C communications.
   5. Develop code to process incoming images from LiDar sensor to make μBiPed respond according to specifications.

Brian Walton

1. Servos
   1. Conduct mechanical stress tests to specify the maximum torque allowed by servos.
   2. Conduct tests to determine the appropriate PWM signal to acquire proper servo rotations.
2. Gyroscope
   1. Will test gyros for tolerance values and resolution to develop mathematical formulas for the equations
   2. Will test for any changes to the chip
3. LiDar
   1. Will test and research LiDar sensor to determine optimal operation with algorithms.
   2. Will develop equations for operation of LiDar system.
4. Will work with Computer Systems and Software to optimize servos and gyroscopes.
5. Will constantly scrutinize design for noise or power issues.

PRELIMINARY PROJECT PLAN

Work Breakdown Structure
(Paul)

Project Schedule: Top Level Schedule
(Paul)

System/Subsystem Level Tasks
(Michael, Railly, Brian)

• What are the tasks for the Manufacturing Engineer?
  • Create rapid prototype to test code created by the Systems Engineer.
  • Create CAD designs of the final design.
  • Learn how to use CNC machines to fabricate the design.
  • Acquire more information on how to use CSULB CNC machines.
  • Will order the components in full for assembly

• What are the tasks for Systems Engineer?
  • Will learn C++ programming language to code algorithms using the Arduino IDE.
  • Will work with Controls division member to optimize servos and gyroscopes.
  • Learn how to use IGT-3200 Wireless adapter.
  • Will work with Controls division on adapting algorithms used in walking of bipedal robot

• What are the tasks for Electronics & Controls Engineer?
  
  • Servos
    • Conduct mechanical stress tests to specify the maximum torque allowed by servos.
    • Conduct tests to determine the appropriate PWM signal to acquire proper servo rotations.
  • Conduct tests to determine the appropriate PWM signal to acquire proper servo rotations.
    • Will test gyros for tolerance values and resolution to develop mathematical formulas for the equations
    • Will test for any changes to the chip
  • Ultrasonic
    • Will test and research ultrasonic sensor to determine optimal operation with algorithms
    • Will develop equations for operation of LiDar system.
  • Will work with Computer Systems and Software to optimize servos and gyroscopes.
  • Will constantly scrutinize design for noise or power issues.
  • Algorithms
    • Modify frame capture code from Mr. Dowdall to accompany a new two servo design.
    • Create state diagrams for the walking frames and the transitions from each frame to the next.
    • Code complex algorithms to determine behavior of μBiPed when on or approaching inclined surfaces.
    • Code algorithms to calibrate and read input from gyroscopes using I2C communications
    • Develop code to process incoming images from LiDar sensor to make μBiPed respond according to specifications.
      

Burn down & Project Percent Completion
(Paul)

System Resource Report
(Railly)

Power Budget

Device	Quantity	Operating DC Volts (V)	Min. Current (mA)	Max. Current (mA)	Avg. Current (mA)	TotalCurrent(mA)	Power(mW)	Margin of error
Ultrasonic sensor        (HC-SR04TM)	1	5	10	20	15	15	75	15%
Gyro          (ITG-3200)	1	3.6	6	10	8	8	28.8	15%
Bluetooth Device (HC-06TM)	1	3.3	10	40	25	25	82.5	15%
Micro Servos (MG92B)	6	5	200	480	340	2040	10200	15%
Arduino Micro (32u4)	1	5	40	50	45	45	225	15%
TOTAL						2133	10612

The table above is a power budget for the μBiped. The limiting factor is the amount of current available from the battery supply which is (14) A. Therefore, the system as a whole must draw less than (a) A. The total current draw is calculated to be (7) A. This results in a margin of 200% (14/7 x 100).

Project Cost Estimation
(Paul, Brian, Railly, Michael)

Parts	Quantity	Price	Uncertainty	High
Ultrasonic sensor(HC-SR04TM)	2	$6.00	300%	$12.00
Gyro(ITG-3200)	1	$25.00	25%	$31.00
Bluetooth Device (HC-06TM)	1	$6.00	25%	$7.50
Micro Servos (MG92B)	6	$45.00	15%	$51.75
Arduino Micro (32u4)	1	$15.00	100%	$30.00
Battery	2	$40.00	50%	$60.00
Battery Charger	1	$20.00	50%	$30.00
2 Layer PCB	3	$46.00	10%	$50.60
Epoxy	1	$6.50	100%	$13.00
3D Printed Frame Set	2	–	–	–
A26509-40-ND CONN HDR BRKWAY	2	–	–	–
CONN FEMALE 34POS	2	$3.06	100%	$6.12
S7004-ND CONN HEADER FEMALE 6POS	3	$2.04	100%	$4.08
S5520-ND CONN HEADER FEMALE 12POS	1	$1.53	100%	$3.06
Splitter Parallel Battery Connector	1	$6.00	75%	$10.50
Connector Adapter Plug Converter	1	$7.00	75%	$12.25
Shipping Costs & Tax	–	$45.00	100%	$90.00
Total w/ Margin		328.13
Budget		400.00
Contingency		71.87