Drivetrain Idea - "Box Drive"

[pimathbrainiac]

That design uses pneumatic wheels, not traction wheels, though. Traction wheels might not actuate properly.

Also that design doesn't do diagonals or moving while rotating, which are key to be able to do for a field-centric system. I don't know of a non omni/mecanum/swerve/h drive that can do this, though.

That said, that drivetrain looks effective for Rebound Rumble, so it served its purpose well, and might serve another purpose later. It just won't serve my purpose currently.

[pimathbrainiac]

I redid the Drivetrain code to normalize the motor values. How is the code? (Just ctrl-A ctrl-V'd it)

// RobotBuilder Version: 1.0
//
// This file was generated by RobotBuilder. It contains sections of
// code that are automatically generated and assigned by robotbuilder.
// These sections will be updated in the future when you export to
// Java from RobotBuilder. Do not put any code or make any change in
// the blocks indicating autogenerated code or it will be lost on an
// update. Deleting the comments indicating the section will prevent
// it from being updated in the future.
package org.usfirst.frc1127.DevBot2014_2015.subsystems;
import org.usfirst.frc1127.DevBot2014_2015.RobotMap;
import org.usfirst.frc1127.DevBot2014_2015.commands.*;
import edu.wpi.first.wpilibj.*;
import edu.wpi.first.wpilibj.command.Subsystem;
/**
 *
 */
public class Drivetrain extends Subsystem
{
    //constants
    final double DISTANCE_X = 1.0;
    final double DISTANCE_Y = 1.0;
    
    //only needed for field-centric
    final double PI = 3.1415926;
    
    //wheel velocity values | positive x values are right | positive y values are forwards
    private double[] motorValues = {0.0, 0.0, 0.0, 0.0};
    
    //rotation is cw
    private double rotationX;
    private double rotationY;
    
    //field-centric stuff
    private double curr_gyro_angle_degrees = 0.0;
    private double curr_gyro_angle_radians = 0.0;
    private double cos;
    private double sin;
    private double temp;
    
    //for the for loop
    private int i;
    double maxValue = 1.0;
    
    // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DECLARATIONS
    CANJaguar cANJaguar1 = RobotMap.drivetrainCANJaguar1;
    CANJaguar cANJaguar2 = RobotMap.drivetrainCANJaguar2;
    RobotDrive robotDrive2X = RobotMap.drivetrainRobotDrive2X;
    CANJaguar cANJaguar3 = RobotMap.drivetrainCANJaguar3;
    CANJaguar cANJaguar4 = RobotMap.drivetrainCANJaguar4;
    RobotDrive robotDrive2Y = RobotMap.drivetrainRobotDrive2Y;
    Gyro gyro1 = RobotMap.drivetrainGyro1;
    // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DECLARATIONS
    
    // Put methods for controlling this subsystem
    // here. Call these from Commands.
    public void initDefaultCommand()
    {
        // BEGIN AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DEFAULT_COMMAND
        setDefaultCommand(new DriveWithJoysticks());
    // END AUTOGENERATED CODE, SOURCE=ROBOTBUILDER ID=DEFAULT_COMMAND
	
        // Set the default command for a subsystem here.
        //setDefaultCommand(new MySpecialCommand());
    }
    
    public void TakeJoystickInputsAndDrive(Joystick left, Joystick right)
    {
        calculatedDrive(left.getY(), left.getX(), right.getX());
    }
    
    void calculatedDrive(double y, double x, double rotation)
    {
        //Field-centric adjustments. Comment out for robot-centric.
        curr_gyro_angle_degrees = gyro1.getAngle();
        curr_gyro_angle_radians = curr_gyro_angle_degrees * (PI / 180);
        cos = Math.cos(curr_gyro_angle_radians);
        sin = Math.sin(curr_gyro_angle_radians);
        temp = y * cos - x * sin;
        x = y * sin + x * cos;
        y = temp;
        
        //This code is needed for both robot-centric and field-centric
        rotationX = rotation * DISTANCE_X;
        rotationY = rotation * DISTANCE_Y;
        motorValues[0] = y - rotationY;
        motorValues[1] = y + rotationY;
        motorValues[2] = x - rotationX;
        motorValues[3] = x + rotationX;
        
        maxValue = 1.0;
        for(i = 0; i < 4; i++)
        {
            if(motorValues[i] > maxValue)
                maxValue = motorValues[i];
        }
        
        if(maxValue > 1.0)
            for(i = 0; i < 4; i++)
                motorValues[i] = motorValues[i] / maxValue;
        
        drive(motorValues[0], motorValues[1], motorValues[2], motorValues[3]);
    }
    
    void drive(double y1, double y2, double x1, double x2)
    {
        //left, right
        robotDrive2Y.drive(y1, y2);
        //front, back
        robotDrive2X.drive(x1, x2);
    }
    
    public void stop()
    {
        robotDrive2Y.drive(0, 0);
        robotDrive2X.drive(0, 0);
    }
}