Scioly.org

NilaiVemula wrote:Our team's Electric Vehicle just got 5th in the Tennessee State Science Olympiad Division C Tournament, but our team overall got 1st. Our distance score was 29 cm and our time score was 4 sec with no bonus. (Our distance would have been more accurate, but the vehicle skid while braking.) For nationals, we want to improve our vehicle by allowing it to turn and get the bonus. Has anyone tried using a turning system in which they program their vehicle to make 90-degree turns to get off the center line at the beginning, turn right and travel for about 10-20 cm, turn left to be parallel with the center line, go forward through the cans, and then turn back onto the center line? We are currently debating whether that would be easier to program than having the car travel in an arc. The current set up of our vehicle has two motors, each driving its own front axle. This allows us to program different speeds for each motor.

NilaiVemula wrote:

Bazinga+ wrote:Here is my Electric Vehicle as well as the steering mechanism I used:

https://www.youtube.com/watch?v=pKC8MYR ... e=youtu.be

I highly recommend using the caliper steering method as it has worked very well for me and others that have used it, with the top 3 vehicles at MIT invitationals using this mechanism.

How did you attach the bearing block to the caliper?

NilaiVemula wrote:Our team's Electric Vehicle just got 5th in the Tennessee State Science Olympiad Division C Tournament, but our team overall got 1st. Our distance score was 29 cm and our time score was 4 sec with no bonus. (Our distance would have been more accurate, but the vehicle skid while braking.) For nationals, we want to improve our vehicle by allowing it to turn and get the bonus. Has anyone tried using a turning system in which they program their vehicle to make 90-degree turns to get off the center line at the beginning, turn right and travel for about 10-20 cm, turn left to be parallel with the center line, go forward through the cans, and then turn back onto the center line? We are currently debating whether that would be easier to program than having the car travel in an arc. The current set up of our vehicle has two motors, each driving its own front axle. This allows us to program different speeds for each motor.

cubes wrote:I am using a servo from an rc car for the steering of my EV but it seems that a change of just 1 degree in my Arduino program is enough to change the car from swerving to the left to the right. Are there any tips for controlling the direction of the EV using rc steering servos?

Bazinga+ wrote:

cubes wrote:I am using a servo from an rc car for the steering of my EV but it seems that a change of just 1 degree in my Arduino program is enough to change the car from swerving to the left to the right. Are there any tips for controlling the direction of the EV using rc steering servos?

Don't, servos are simply not precise enough for controlling steering.

windu34 wrote:

NilaiVemula wrote:Our team's Electric Vehicle just got 5th in the Tennessee State Science Olympiad Division C Tournament, but our team overall got 1st. Our distance score was 29 cm and our time score was 4 sec with no bonus. (Our distance would have been more accurate, but the vehicle skid while braking.) For nationals, we want to improve our vehicle by allowing it to turn and get the bonus. Has anyone tried using a turning system in which they program their vehicle to make 90-degree turns to get off the center line at the beginning, turn right and travel for about 10-20 cm, turn left to be parallel with the center line, go forward through the cans, and then turn back onto the center line? We are currently debating whether that would be easier to program than having the car travel in an arc. The current set up of our vehicle has two motors, each driving its own front axle. This allows us to program different speeds for each motor.

Bad idea. You will lose too much accuracy and it will slow you down and the programming will be a pain and you will likely hit a can. Do the arc with fixed steering

Bazinga+ wrote:

NilaiVemula wrote:

Bazinga+ wrote:Here is my Electric Vehicle as well as the steering mechanism I used:

https://www.youtube.com/watch?v=pKC8MYR ... e=youtu.be

I highly recommend using the caliper steering method as it has worked very well for me and others that have used it, with the top 3 vehicles at MIT invitationals using this mechanism.

How did you attach the bearing block to the caliper?

Epoxy and metal clips. There was no cleaner way to do it since you can't drill into a hardened steel caliper :'(

cubes wrote:I am using a servo from an rc car for the steering of my EV but it seems that a change of just 1 degree in my Arduino program is enough to change the car from swerving to the left to the right. Are there any tips for controlling the direction of the EV using rc steering servos?

Bazinga+ wrote:

NilaiVemula wrote:

Bazinga+ wrote:Here is my Electric Vehicle as well as the steering mechanism I used:

https://www.youtube.com/watch?v=pKC8MYR ... e=youtu.be

I highly recommend using the caliper steering method as it has worked very well for me and others that have used it, with the top 3 vehicles at MIT invitationals using this mechanism.

How did you attach the bearing block to the caliper?

Epoxy and metal clips. There was no cleaner way to do it since you can't drill into a hardened steel caliper :'(