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Bronco Bots

Drivetrain

Drivetrain Subsystem Overview

Section titled “Drivetrain Subsystem Overview”

The DriveTrain.java class provides a abstractoin layer upon the bare motors that power the drive train. It is built around a Mecanum drive and implement a full FDIR loop to detect motor failures.

Class Architecture

Section titled “Class Architecture”
Property Value
Package Path org.firstinspires.ftc.teamcode.systemsControls.DriveTrain
Type Utility / Subsystem

Constructor

Section titled “Constructor”
Argument Type Description
flName String name of the front-left drive motor
frName String name of the front-right drive motor
blName String name of the back-left drive motor
brName String name of the front-right drive motor
motorDirections Map directions of all the motors
maxMotorPower float Maximum power to supply to the motors
hardwareMap HardwareMap the opModes hardware map
follower Follower Reference to the follower used throughout TeleOp

Method Reference

Section titled “Method Reference”

1. moveWithFDIRPipeline

Section titled “1. moveWithFDIRPipeline”
public void moveWithFDIRPipeline(float x, float y, float rotation)

Commands drivetrain movement while running the Fault Detection, Isolation, and Recovery (FDIR) system.

The FDIR pipeline monitors drivetrain performance and attempts to detect failed or stalled motors. If a motor failure is detected, the drivetrain automatically changes behavior to maintain control when possible.

Parameters

Section titled “Parameters”
Name Type Description
x float Requested strafe movement.
y float Requested forward/backward movement.
rotation float Requested rotational movement.

Return Value

Section titled “Return Value”
Type Description
void Executes the drive command with fault monitoring enabled.

2. moveWithoutFDIR

Section titled “2. moveWithoutFDIR”
public void moveWithoutFDIR(float x, float y, float rotation)

Commands standard mecanum drivetrain movement without running fault detection.

This method should be used when motor failure detection is not required.

Parameters

Section titled “Parameters”
Name Type Description
x float Requested strafe movement.
y float Requested forward/backward movement.
rotation float Requested rotational movement.

Return Value

Section titled “Return Value”
Type Description
void Applies movement commands directly to the drivetrain.

3. setMotorPowerRaw

Section titled “3. setMotorPowerRaw”
public void setMotorPowerRaw(float fl, float fr, float bl, float br)

Directly sets power values for each individual drivetrain motor.

Power values are automatically clipped between -1 and 1.

Parameters

Section titled “Parameters”
Name Type Description
fl float Front-left motor power.
fr float Front-right motor power.
bl float Back-left motor power.
br float Back-right motor power.

Return Value

Section titled “Return Value”
Type Description
void Applies raw motor power values.

4. brake

Section titled “4. brake”
public void brake()

Stops all drivetrain motors.

Return Value

Section titled “Return Value”
Type Description
void Sets all motor powers to zero.

5. resetEncoders

Section titled “5. resetEncoders”
public void resetEncoders()

Resets all drivetrain motor encoders while restoring their previous run modes.

Return Value

Section titled “Return Value”
Type Description
void Resets drivetrain encoder positions.

6. resetSingleMotorEncoder

Section titled “6. resetSingleMotorEncoder”
public static void resetSingleMotorEncoder(DcMotorEx motor)

Resets the encoder of a single motor while preserving its previous run mode.

Parameters

Section titled “Parameters”
Name Type Description
motor DcMotorEx Motor whose encoder should be reset.

Return Value

Section titled “Return Value”
Type Description
void Resets the selected motor encoder.

7. devTelemetry

Section titled “7. devTelemetry”
public void devTelemetry(Telemetry tele, boolean verbose)

Displays drivetrain debugging telemetry including motor power and optional motor diagnostics.

Parameters

Section titled “Parameters”
Name Type Description
tele Telemetry Telemetry instance used to display data.
verbose boolean Whether additional diagnostic information should be displayed.

Return Value

Section titled “Return Value”
Type Description
void Adds drivetrain telemetry data.

8. devTelemetry

Section titled “8. devTelemetry”
public void devTelemetry(Telemetry tele, boolean verbose, float X, float Y, float rotation)

Displays drivetrain debugging telemetry with the requested drive inputs included.

Parameters

Section titled “Parameters”
Name Type Description
tele Telemetry Telemetry instance used to display data.
verbose boolean Whether additional diagnostic information should be displayed.
X float Requested strafe input.
Y float Requested forward/backward input.
rotation float Requested rotation input.

Return Value

Section titled “Return Value”
Type Description
void Adds drivetrain telemetry data.

9. normalizeDegrees

Section titled “9. normalizeDegrees”
public static double normalizeDegrees(double degrees)

Converts an angle into a normalized range between -180 and 180 degrees.

Parameters

Section titled “Parameters”
Name Type Description
degrees double Input angle in degrees.

Return Value

Section titled “Return Value”
Type Description
double Normalized angle.

FDIR Overview

Section titled “FDIR Overview”

FDIR stands for Fault Detection, Isolation, and Recovery.

The drivetrain uses multiple sensor inputs to identify possible motor failures:

  • Comparing commanded movement against actual robot movement using cosine similarity.
  • Monitoring motor current draw to detect stalled motors.
  • Checking the number of affected motors to avoid false positives caused by external forces or sensor failures.
  • Requiring failure conditions to persist before disabling a motor.

When possible, the drivetrain will continue operating with reduced capability after detecting a motor failure.