Lab 4: Car #1

Mobile Base Description:

Our robot uses 3-wheel differential drive with a caster wheel in the front in order to move. We then implemented PD control on the two wheels in order to ensure that they moved at the same speed and kept the car moving in a straight line or turning in a controlled way.

The bottom layer of the base stores the circuit and has room to screw in a protoboard, and the top layer holds the batteries needed for the base. The bottom layer of the base was 5”x7” and all holes and attachments were based on attached parts.

Performance: 

Time Around the Track: 2:18 (Video below)

Improvements: One improvement we thought of implementing was including an axel controlled by a servo. This would likely need to be done with 4-wheels, however, it could be controlled with front-wheel drive. The front wheels turning would be controlled by the axel movement and their speeds would be controlled through PID. Additionally, a lighter battery pack would significantly improve the speed of the robot, and potentially a stronger battery than a 6V could be used to power the motors.

If we were to choose to stay with the 2-wheel differential drive and could be useful to source a better caster. The caster used was a little rough and adding some grease was able to help slightly however it still did not roll smoothly.

Extra Features: 

1. A (Literal) Driver

Something silly we added was a OLED screen with a 3D printed holder that is a robot with a cowboy hat. Originally, the screen was used to print various values to confirm our PID was functioning as intended when the car was connected to a battery. After we no longer needed that, it was something we used as a brain break- to make it “drive” our car and react happily to going forward and backward, surprised when it was turning, or inquisitively when stopped.

2. Soldered Protoboard

We soldered our circuit for a cleaner look.