org.firstinspires.ftc.teamcode.legacy.hardware.tankdrive

Class Drivetrain

java.lang.Object

org.firstinspires.ftc.teamcode.hardware.Mechanism

org.firstinspires.ftc.teamcode.legacy.hardware.tankdrive.Drivetrain

public class Drivetrain
extends Mechanism

Drivetrain is the class that is used to define all of the hardware for a robot's drivetrain. Drivetrain must be instantiated, then initialized using init() before being used. This class also contains autonomous actions involving the drivetrain. encoderInit() must be called before an autonomous action can be called. This class describes a tank drivetrain.

Field Summary

Fields

Modifier and Type	Field and Description
(package private) double	globalAngle
private com.qualcomm.hardware.bosch.BNO055IMU	imu
(package private) org.firstinspires.ftc.robotcore.external.navigation.Orientation	lastAngles
(package private) double	left
private com.qualcomm.robotcore.hardware.DcMotor	leftBack
private com.qualcomm.robotcore.hardware.DcMotor	leftFront
(package private) double	max
(package private) PIDController	pidDrive
(package private) PIDController	pidRotate
(package private) double	power
(package private) double	right
private com.qualcomm.robotcore.hardware.DcMotor	rightBack
private com.qualcomm.robotcore.hardware.DcMotor	rightFront

Fields inherited from class org.firstinspires.ftc.teamcode.hardware.Mechanism

opMode

Constructor Summary

Constructors

Constructor and Description
Drivetrain() Default constructor for Drivetrain.
Drivetrain(com.qualcomm.robotcore.eventloop.opmode.LinearOpMode opMode) Overloaded constructor for Drivetrain.

Method Summary

Modifier and Type	Method and Description
void	driveArcade(double y_value, double x_value) Set drivetrain motor power Arcade style based on input.
void	driveParametric(double v_y, double v_x, double v_rot)
void	driveStraightPID(double speed, double correction) Drive accurately using a PID loop.
void	driveTank(double left, double right) Set drivetrain motor power Tank style based on input.
void	driveToPos(double speed, double leftInches, double rightInches, double timeoutS) Drive to a relative position using encoders and an IMU.
void	encoderInit() Initializes motors for encoder driving.
private double	getAngle() Get current cumulative angle rotation from last reset.
private double	getError(double targetAngle)
double	getHeading()
double[]	getPositions()
void	init(com.qualcomm.robotcore.hardware.HardwareMap hwMap) Initializes drivetrain hardware.
void	resetAngle()
private void	rotate(int degrees, double power) Rotate left or right the number of degrees.
void	turn(double angle, double timeoutS) Turn to a specified angle using an IMU.
void	turnPID(int angle) Turn to a specified angle accurately using a PID loop.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

leftFront

private com.qualcomm.robotcore.hardware.DcMotor leftFront

leftBack

private com.qualcomm.robotcore.hardware.DcMotor leftBack

rightFront

private com.qualcomm.robotcore.hardware.DcMotor rightFront

rightBack

private com.qualcomm.robotcore.hardware.DcMotor rightBack

imu

private com.qualcomm.hardware.bosch.BNO055IMU imu

left

double left

right

double right

max

double max

lastAngles

org.firstinspires.ftc.robotcore.external.navigation.Orientation lastAngles

globalAngle

double globalAngle

power

double power

pidRotate

PIDController pidRotate

pidDrive

PIDController pidDrive

Constructor Detail

Drivetrain

public Drivetrain()

Default constructor for Drivetrain.

Drivetrain

public Drivetrain(com.qualcomm.robotcore.eventloop.opmode.LinearOpMode opMode)

Overloaded constructor for Drivetrain. Sets the OpMode context.

Parameters:

opMode - the LinearOpMode that is currently running

Method Detail

init

public void init(com.qualcomm.robotcore.hardware.HardwareMap hwMap)

Initializes drivetrain hardware.

Specified by:

init in class Mechanism

Parameters:

hwMap - robot's hardware map

encoderInit

public void encoderInit()

Initializes motors for encoder driving. Must be called before calling methods that use encoders.

driveArcade

public void driveArcade(double y_value,
                        double x_value)

Set drivetrain motor power Arcade style based on input.

Parameters:

y_value - power for left side of drivetrain (-1 to 1)

x_value - power for right side of drivetrain (-1 to 1)

driveTank

public void driveTank(double left,
                      double right)

Set drivetrain motor power Tank style based on input.

Parameters:

left - power for left side of drivetrain (-1 to 1)

right - power for right side of drivetrain (-1 to 1)

driveParametric

public void driveParametric(double v_y,
                            double v_x,
                            double v_rot)

driveToPos

public void driveToPos(double speed,
                       double leftInches,
                       double rightInches,
                       double timeoutS)

Drive to a relative position using encoders and an IMU. Robot will stop moving if any of three conditions occur:

• Move gets to the desired position
• Move runs out of time
• Driver stops the running OpMode

Parameters:

speed - maximum power of drivetrain motors when driving

leftInches - number of inches to move on the left side

rightInches - number of inches to move on the right side

timeoutS - amount of time before the move should stop

driveStraightPID

public void driveStraightPID(double speed,
                             double correction)

Drive accurately using a PID loop.

Parameters:

speed - speed at which the motor shall turn

correction - a placeholder value for PID output in case correction isnt given a new value

turnPID

public void turnPID(int angle)

Turn to a specified angle accurately using a PID loop.

Parameters:

angle - number of degrees to turn

turn

public void turn(double angle,
                 double timeoutS)

Turn to a specified angle using an IMU. Robot will stop moving if any of three conditions occur:

Move gets to the desired angle

Move runs out of time

Driver stops the running OpMode

Parameters:

angle - number of degrees to turn

timeoutS - amount of time before the move should stop

getHeading

public double getHeading()

getError

private double getError(double targetAngle)

getPositions

public double[] getPositions()

resetAngle

public void resetAngle()

getAngle

private double getAngle()

Get current cumulative angle rotation from last reset.

Returns:

Angle in degrees. + = left, - = right from zero point.

rotate

private void rotate(int degrees,
                    double power)

Rotate left or right the number of degrees. Does not support turning more than 180 degrees. Starts pid controller. PID controller will monitor the turn angle with respect to the target angle and reduce power as we approach the target angle with a minimum of 20%. This is to prevent the robots momentum from overshooting the turn after we turn off the power. The PID controller reports onTarget() = true when the difference between turn angle and target angle is within 2% of target (tolerance). This helps prevent overshoot. The minimum power is determined by testing and must enough to prevent motor stall and complete the turn. Note: if the gap between the starting power and the stall (minimum) power is small, overshoot may still occur. Overshoot is dependant on the motor and gearing configuration, starting power, weight of the robot and the on target tolerance.

Parameters:

degrees - Degrees to turn, + is left - is right