Chief Delphi - 4 Motor Drive

Chief Delphi (http://www.chiefdelphi.com/forums/index.php)

- Java (http://www.chiefdelphi.com/forums/forumdisplay.php?f=184)

- - 4 Motor Drive (http://www.chiefdelphi.com/forums/showthread.php?t=81998)

Hello, our team is having trouble, and we need help. We're using a 4 wheeled drive (w/Mecanum wheels), but we can't figure out how to program it as a tank drive. Can anyone out there help us?

Re: 4 Motor Drive

Start with the given Simple Robot Template and add the import "edu.wpi.first.wpilibj.*"

Then add

Code:

    RobotDrive drive = new RobotDrive(1,2,3,4);

    Joystick leftStick = new Joystick(1);

    Joystick rightStick = new Joystick(2);

under "public class RobotTemplate extends SimpleRobot"

Then add

Code:

drive.tankDrive(leftStick,rightStick);

under "public void operatorControl()".

This will give you a tank drive system for a four motor robot with front left motor in port 1, back left in port 2, front right in port 3, and rear right in port 4 using the left joystick in port 1 and the right joystick in port 2. Best of luck :)

Re: 4 Motor Drive

There is a specific function built for Mecanum wheel drive that you may find useful called holonomic drive. Now, it's not tank drive, but it does provide videogame-like controls for left-right strafing:

in the RobotTemplate() constructor, as before:

m_robotDrive = new RobotDrive(1, 3, 2, 4);
m_rightStick = new Joystick(1);
m_leftStick = new Joystick(2);

and in teleopPeriodic()
m_robotDrive.holonomicDrive( m_leftStick.getMagnitude(), m_leftStick.getDirectionDegrees() ,m_rightStick.getX());

We got this code to work, and plugged the PWM cables in as such:

Front of Robot
1 2

3 4
Rear of Robot

The only thing to note is, in this configuration motors 2 & 4 need to have their Jaguar M- and M+ motor power outputs reversed to the motors in order to work properly. Otherwise, you could fix this issue in your code by using the setInvertedMotor() function on 2 & 4. You can see our robot in action here. Hope this helps!

Re: 4 Motor Drive

what if were are using victors ? what does it need to be done on the code to use victors ?

Re: 4 Motor Drive

Victors more or less = jaguars