Week 19 - November 14-20

Software module

• Code adjustments produced more ideal results than Saturdays test of sensors, but the issue now is the cart wants to do two actions (back and strafe) when an object is seen in front. It was needed to change the order of the if-else statements.

• Fixed issue where directions were sideways on app, but PWM speed needs to be tuned when cart is on ground.

But for the most part the code shows the cart can react as needed to obstacles and signal strength change, the order of conditions needs to just to be fine tuned.

Mechanical module

It was needed to dismantle wheels and shaft and give to Victoria and see if she can find a solution to the wheel issue. The plate that is between each motor also needs to be cut in half so that way each pair of motors, front and back, has something in between them that will prevent them from wanting to slide when they turn the pulley and feel extreme torque from the wheel wanting to turn.

While still working with Victoria to find solutions for the mounting the proximity and transceiver sensors, zip ties were used to temporarily hold the sensors up around the cart for testing and verifying the obstacle avoidance procedures can work. This method of testing the sensor seems to work, because it gives a good idea of the distances and regions that each sensor can cover. The infrared transceivers are a lot more sensitive than anticipated so some adjusting of their proximity range needs to be done but the ultrasonic sensor and infrared sensors to its left and right seem to cover any spots on the front and back as expected. The cart's motors also react accordingly to the sensors, with if any of the sensors on the front detecting anything, the cart will strafe left or right depending on which side the front infrared sensors have detected something. Essentially if the left proximity sensor detects something the cart will want to strafe right as long as there are no obstacles on the right, and vice versa, while if both the front and the left detect something the cart will want to back up, else stop if any more obstacles are encountered. Figure 1 shows an IR proximity sensor on the cart.

Figure 1: IR proximity sensor on the cart, covers front and front right of the cart's area of operation.