The main types of object detection we will be looking at are camera module, inductive, capacitive, ultrasonic, TOF (Time-of-Flight), and RFID sensors. We will be looking at the cost, dimensions, operating voltage, and measuring distance of the specific devices. Below is a table of the possible object detection device that we might be able to use.

Figure 1. Object Detection Devices

First, we will address specific requirements for our FuzzyBear robot. FuzzyBear is required to be able to detect an object within its path when it comes within 40 mm of the object. If the object detecting device fails to meet this requirement, we will have failed the functional requirement that determines our grade. Also, FuzzyBear has an operating voltage of 3.3 V internal battery and a, unregulated 5 V external battery. Our required cost for the device is $20 based on the allocated budget. Finally, the device should be able to fit in the head of our FuzzyBear skin. The maximum dimension that the device can be is 45 mm x 30 mm x 30 mm.

All the parts are well within our budget, but other factors will be looked at. Looking at the numbers we can already rule out the RC522 RFID Module and the LJ123-4/BY Inductive Sensor because the dimensions exceed that of our FuzzyBear head. Next, we will be looking at the operating voltage of all devices compared to what FuzzyBear can supply. Operating voltages for all components are in range of the project because we have an external battery supplying about 5V and a battery on the 3Dot supplying 3.3V. Lastly, we will look at the the measuring distance of the sensors. The only forms of object detection that will help us achieve our goal of at least 40 mm distance is the VL53L0X TOF Distance Sensor and the HC-SR04 Ultrasonic Sensor as they can measure distances of 30 mm to 1000 mm and 20 mm to 4000 mm, respectively.