Coasting vs Power Braking

Coasting Graphs:
Power vs. Time
Power vs. Distance
Power Braking Graphs:
Power vs. Time
Power vs. Distance
Analysis:
To stop the AEV, the team can let the AEV coast on the track or, the team will use power braking to make the AEV quickly stop. In power braking, after running the intended code, the motors will be reversed so that the vehicle will stop at a much earlier distance. This method is beneficial when on a time constraint or when needing to have greater control of the AEV. At the same time, using power breaking significantly increases power consumption. Coasting, on the other hand, is more efficient as it uses less power, but also takes more time for the vehicle to come to rest. To test the two methods, the team ran two sets of code as seen below.

//Coasting test

//Run all motors at 35% power for 4 seconds
motorSpeed(4,30);
goFor(4);

//Power Braking Test

//Run all motors at 35% power for 4 seconds
motorSpeed(4,30);
goFor(4);

//Reverse the direction of the motors
reverse(4);

//Run all motors at 30% power for 2 seconds
motorSpeed(4,30);
goFor(2);

The results of the test shows that power braking stops the AEV at 3.28 meters and takes a total of 11.31 watts whereas for coasting, the AEV stopped at 6.51 meters and used a total power of 7.94 watts. Comparing the data allowed the team to determine that power braking stops 3.32 meters earlier and uses 3.37 more watts. After running the tests, the team concluded that a servo motor used for the braking system would be the optimal way to stop the AEV. This will stop the vehicle quicker than letting it coast and will also use a smaller amount of power  braking. Using the servo motor will lead to braking quicker and having greater control over the vehicle which will reduce the overall time it takes the AEV to complete a run.