[FTC]: [FTC]: Autonomous-run motor with encoders does not stop

[FRC Team CC]

We are trying write an autonomous program to drive the robot a specified distance. we have connected encoders to our 4 drive motors and here is the code we have so far :

public class CCAutonomous extends LinearOpMode {
    OpticalDistanceSensor opticalDistanceSensor;
    //Drive motors
    DcMotor motorFrontRight,motorFrontLeft, motorBackRight, motorBackLeft;

    @Override
    public void runOpMode() throws InterruptedException {

       // opticalDistanceSensor = hardwareMap.opticalDistanceSensor.get("sensor_ods");

        motorFrontRight = hardwareMap.dcMotor.get("front_right");
        motorFrontLeft = hardwareMap.dcMotor.get("front_left");
        motorBackRight = hardwareMap.dcMotor.get("back_right");
        motorBackLeft = hardwareMap.dcMotor.get("back_left");

        motorFrontLeft.setDirection(DcMotor.Direction.REVERSE);
        motorBackLeft.setDirection(DcMotor.Direction.REVERSE);
        motorFrontRight.setMode(DcMotorController.RunMode.RUN_USING_ENCODERS);
        motorFrontLeft.setMode(DcMotorController.RunMode.RUN_USING_ENCODERS);
        motorBackRight.setMode(DcMotorController.RunMode.RUN_USING_ENCODERS);
        motorBackLeft.setMode(DcMotorController.RunMode.RUN_USING_ENCODERS);
        waitForStart();
        // Reset enoders to zero
        motorFrontLeft.setMode(DcMotorController.RunMode.RESET_ENCODERS);
        motorFrontRight.setMode(DcMotorController.RunMode.RESET_ENCODERS);
        motorBackLeft.setMode(DcMotorController.RunMode.RESET_ENCODERS);
        motorBackRight.setMode(DcMotorController.RunMode.RESET_ENCODERS);
        waitOneFullHardwareCycle(); // We use these in attempt to gain stability.


        motorFrontLeft.setTargetPosition(2440);
        motorFrontRight.setTargetPosition(2440);
        motorBackLeft.setTargetPosition(2440);
        motorBackRight.setTargetPosition(2440);

        motorFrontRight.setMode(DcMotorController.RunMode.RUN_TO_POSITION);
        motorFrontLeft.setMode(DcMotorController.RunMode.RUN_TO_POSITION);
        motorBackRight.setMode(DcMotorController.RunMode.RUN_TO_POSITION);
        motorBackLeft.setMode(DcMotorController.RunMode.RUN_TO_POSITION);
        motorFrontLeft.setPower(-0.5);
        motorFrontRight.setPower(-0.5);
        motorBackLeft.setPower(-0.5);
        motorBackRight.setPower(-0.5);

        telemetry.addData("2 ", "motorFrontLeft:  " + String.format("%d", motorFrontLeft.getTargetPosition()));
        telemetry.addData("3 ", "motorFrontRight:  " + String.format("%d", motorFrontRight.getTargetPosition()));
        telemetry.addData("4 ", "motorBackLeft:  " + String.format("%d", motorBackLeft.getTargetPosition()));
        telemetry.addData("5 ", "motorBackRight:  " + String.format("%d", motorBackRight.getTargetPosition()));
    }
}

With the power set to -0.5, the robot keeps moving and does not stop. How do we stop the robot after moving specified distance.

thanks
Charging Champions
Team 8660

[whereisthemonke]

Hey, i would use the following code:

PHP Code:

public class CCAutonomous extends LinearOpMode {
        OpticalDistanceSensor opticalDistanceSensor;
        //Drive motors
        DcMotor motorFrontRight,motorFrontLeft, motorBackRight, motorBackLeft;
        int leftFrontPos, leftBackPos, rightFrontPos, rightBackPos;

        @Override
        public void runOpMode() throws InterruptedException {

            // opticalDistanceSensor = hardwareMap.opticalDistanceSensor.get("sensor_ods");

            motorFrontRight = hardwareMap.dcMotor.get("front_right");
            motorFrontLeft = hardwareMap.dcMotor.get("front_left");
            motorBackRight = hardwareMap.dcMotor.get("back_right");
            motorBackLeft = hardwareMap.dcMotor.get("back_left");

            motorFrontLeft.setDirection(DcMotor.Direction.REVERSE);
            motorBackLeft.setDirection(DcMotor.Direction.REVERSE);
            motorFrontRight.setMode(DcMotorController.RunMode.RUN_USING_ENCODERS);
            motorFrontLeft.setMode(DcMotorController.RunMode.RUN_USING_ENCODERS);
            motorBackRight.setMode(DcMotorController.RunMode.RUN_USING_ENCODERS);
            motorBackLeft.setMode(DcMotorController.RunMode.RUN_USING_ENCODERS);
            waitForStart();
            // Reset enoders to zero
            motorFrontLeft.setMode(DcMotorController.RunMode.RESET_ENCODERS);
            motorFrontRight.setMode(DcMotorController.RunMode.RESET_ENCODERS);
            motorBackLeft.setMode(DcMotorController.RunMode.RESET_ENCODERS);
            motorBackRight.setMode(DcMotorController.RunMode.RESET_ENCODERS);
            waitOneFullHardwareCycle(); // We use these in attempt to gain stability.


            motorFrontLeft.setTargetPosition(2440);
            motorFrontRight.setTargetPosition(2440);
            motorBackLeft.setTargetPosition(2440);
            motorBackRight.setTargetPosition(2440);

            leftFrontPos = motorLeftFront.getCurrentPosition();
            leftBackPos = motorLeftBack.getCurrentPosition();
            rightFrontPos = motorFrontRight.getCurrentPosition();
            rightBackPos = motorBackRight.getCurrentPosition();

            motorFrontRight.setMode(DcMotorController.RunMode.RUN_TO_POSITION);
            motorFrontLeft.setMode(DcMotorController.RunMode.RUN_TO_POSITION);
            motorBackRight.setMode(DcMotorController.RunMode.RUN_TO_POSITION);
            motorBackLeft.setMode(DcMotorController.RunMode.RUN_TO_POSITION);

            while(leftBackPos < 2440 && leftFrontPos < 2440 && rightBackPos < 2440 && rightFrontPos < 2440){
                motorFrontLeft.setPower(-0.5);
                motorFrontRight.setPower(-0.5);
                motorBackLeft.setPower(-0.5);
                motorBackRight.setPower(-0.5);

                leftFrontPos = motorLeftFront.getCurrentPosition();
                leftBackPos = motorLeftBack.getCurrentPosition();
                rightFrontPos = motorFrontRight.getCurrentPosition();
                rightBackPos = motorBackRight.getCurrentPosition();
            }

            telemetry.addData("2 ", "motorFrontLeft:  " + String.format("%d", motorFrontLeft.getTargetPosition()));
            telemetry.addData("3 ", "motorFrontRight:  " + String.format("%d", motorFrontRight.getTargetPosition()));
            telemetry.addData("4 ", "motorBackLeft:  " + String.format("%d", motorBackLeft.getTargetPosition()));
            telemetry.addData("5 ", "motorBackRight:  " + String.format("%d", motorBackRight.getTargetPosition()));
        }
    } 


Use this code instead and tell me if it worked, I will use this code too if you confirm that it worked

[FRC Team CC]

We got around the original issue by setting the motor power to 0 after the Targetposition is reached. We also had an another issue with the condition performing the "and" condition on all 4 motors to check if the target position is reached. Two of the motors where always at zero position so we modified the condition to just check of the front set of wheels (which were the ones with the encoders returning the right values)