Class Models

java.lang.Object

org.wpilib.math.system.Models

public final class Models
extends Object

Linear system factories.

Method Summary

Modifier and Type	Method	Description
static LinearSystem<N2,N2,N2>	differentialDriveFromPhysicalConstants(DCMotor motor, double mass, double r, double rb, double J, double gearing)	Creates a differential drive state-space model from physical constants.
static LinearSystem<N2,N2,N2>	differentialDriveFromSysId(double kVLinear, double kALinear, double kVAngular, double kAAngular)	Creates a differential drive state-space model from SysId constants kᵥ and kₐ in both linear {(V/(m/s), (V/(m/s²))} and angular {(V/(rad/s), (V/(rad/s²))} cases.
static LinearSystem<N2,N2,N2>	differentialDriveFromSysId(double kVLinear, double kALinear, double kVAngular, double kAAngular, double trackwidth)	Creates a differential drive state-space model from SysId constants kᵥ and kₐ in both linear {(V/(m/s), (V/(m/s²))} and angular {(V/(rad/s), (V/(rad/s²))} cases.
static LinearSystem<N2,N1,N2>	elevatorFromPhysicalConstants(DCMotor motor, double mass, double radius, double gearing)	Creates an elevator state-space model from physical constants.
static LinearSystem<N2,N1,N2>	elevatorFromSysId(double kV, double kA)	Creates an elevator state-space model from SysId constants kᵥ (V/(m/s)) and kₐ (V/(m/s²)) from the feedforward model u = kᵥv + kₐa.
static LinearSystem<N1,N1,N1>	flywheelFromPhysicalConstants(DCMotor motor, double J, double gearing)	Creates a flywheel state-space model from physical constants.
static LinearSystem<N1,N1,N1>	flywheelFromSysId(double kV, double kA)	Creates a flywheel state-space model from SysId constants kᵥ (V/(rad/s)) and kₐ (V/(rad/s²)) from the feedforward model u = kᵥv + kₐa.
static LinearSystem<N2,N1,N2>	singleJointedArmFromPhysicalConstants(DCMotor motor, double J, double gearing)	Create a single-jointed arm state-space model from physical constants.
static LinearSystem<N2,N1,N2>	singleJointedArmFromSysId(double kV, double kA)	Creates a single-jointed arm state-space model from SysId constants kᵥ (V/(rad/s)) and kₐ (V/(rad/s²)) from the feedforward model u = kᵥv + kₐa.

Methods inherited from class Object

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

Method Details

flywheelFromPhysicalConstants

public static LinearSystem<N1,N1,N1> flywheelFromPhysicalConstants(DCMotor motor,
 double J,
 double gearing)

Creates a flywheel state-space model from physical constants.

The states are [angular velocity], the inputs are [voltage], and the outputs are [angular velocity].

Parameters:

motor - The motor (or gearbox) attached to the flywheel.

J - The moment of inertia J of the flywheel.

gearing - Gear ratio from motor to flywheel (greater than 1 is a reduction).

Returns:

Flywheel state-space model.

Throws:

IllegalArgumentException - if J <= 0 or gearing <= 0.

flywheelFromSysId

public static LinearSystem<N1,N1,N1> flywheelFromSysId(double kV,
 double kA)

Creates a flywheel state-space model from SysId constants kᵥ (V/(rad/s)) and kₐ (V/(rad/s²)) from the feedforward model u = kᵥv + kₐa.

The states are [velocity], the inputs are [voltage], and the outputs are [velocity].

Parameters:

kV - The velocity gain, in V/(rad/s).

kA - The acceleration gain, in V/(rad/s²).

Returns:

Flywheel state-space model.

Throws:

IllegalArgumentException - if kV < 0 or kA <= 0.

See Also:

• https://github.com/wpilibsuite/allwpilib/tree/main/sysid

elevatorFromPhysicalConstants

public static LinearSystem<N2,N1,N2> elevatorFromPhysicalConstants(DCMotor motor,
 double mass,
 double radius,
 double gearing)

Creates an elevator state-space model from physical constants.

The states are [position, velocity], the inputs are [voltage], and the outputs are [position, velocity].

Parameters:

motor - The motor (or gearbox) attached to the carriage.

mass - The mass of the elevator carriage, in kilograms.

radius - The radius of the elevator's driving drum, in meters.

gearing - Gear ratio from motor to carriage (greater than 1 is a reduction).

Returns:

Elevator state-space model.

Throws:

IllegalArgumentException - if mass <= 0, radius <= 0, or gearing <= 0.

elevatorFromSysId

public static LinearSystem<N2,N1,N2> elevatorFromSysId(double kV,
 double kA)

Creates an elevator state-space model from SysId constants kᵥ (V/(m/s)) and kₐ (V/(m/s²)) from the feedforward model u = kᵥv + kₐa.

The states are [position, velocity], the inputs are [voltage], and the outputs are [position, velocity].

Parameters:

kV - The velocity gain, in V/(m/s).

kA - The acceleration gain, in V/(m/s²).

Returns:

Elevator state-space model.

Throws:

IllegalArgumentException - if kV < 0 or kA <= 0.

See Also:

• https://github.com/wpilibsuite/allwpilib/tree/main/sysid

singleJointedArmFromPhysicalConstants

public static LinearSystem<N2,N1,N2> singleJointedArmFromPhysicalConstants(DCMotor motor,
 double J,
 double gearing)

Create a single-jointed arm state-space model from physical constants.

The states are [angle, angular velocity], the inputs are [voltage], and the outputs are [angle, angular velocity].

Parameters:

motor - The motor (or gearbox) attached to the arm.

J - The moment of inertia J of the arm.

gearing - Gear ratio from motor to arm (greater than 1 is a reduction).

Returns:

Single-jointed arm state-space model.

Throws:

IllegalArgumentException - if J <= 0 or gearing <= 0.

singleJointedArmFromSysId

public static LinearSystem<N2,N1,N2> singleJointedArmFromSysId(double kV,
 double kA)

Creates a single-jointed arm state-space model from SysId constants kᵥ (V/(rad/s)) and kₐ (V/(rad/s²)) from the feedforward model u = kᵥv + kₐa.

The states are [position, velocity], the inputs are [voltage], and the outputs are [position, velocity].

Parameters:

kV - The velocity gain, in volts/(unit/sec).

kA - The acceleration gain, in volts/(unit/sec²).

Returns:

Single-jointed arm state-space model.

Throws:

IllegalArgumentException - if kV < 0 or kA <= 0.

See Also:

• https://github.com/wpilibsuite/allwpilib/tree/main/sysid

differentialDriveFromPhysicalConstants

public static LinearSystem<N2,N2,N2> differentialDriveFromPhysicalConstants(DCMotor motor,
 double mass,
 double r,
 double rb,
 double J,
 double gearing)

Creates a differential drive state-space model from physical constants.

The states are [left velocity, right velocity], the inputs are [left voltage, right voltage], and the outputs are [left velocity, right velocity].

Parameters:

motor - The motor (or gearbox) driving the drivetrain.

mass - The mass of the robot in kilograms.

r - The radius of the wheels in meters.

rb - The radius of the base (half of the trackwidth), in meters.

J - The moment of inertia of the robot.

gearing - Gear ratio from motor to wheel (greater than 1 is a reduction).

Returns:

Differential drive state-space model.

Throws:

IllegalArgumentException - if mass <= 0, r <= 0, rb <= 0, J <= 0, or gearing <= 0.

differentialDriveFromSysId

public static LinearSystem<N2,N2,N2> differentialDriveFromSysId(double kVLinear,
 double kALinear,
 double kVAngular,
 double kAAngular)

Creates a differential drive state-space model from SysId constants kᵥ and kₐ in both linear {(V/(m/s), (V/(m/s²))} and angular {(V/(rad/s), (V/(rad/s²))} cases.

The states are [left velocity, right velocity], the inputs are [left voltage, right voltage], and the outputs are [left velocity, right velocity].

Parameters:

kVLinear - The linear velocity gain in volts per (meters per second).

kALinear - The linear acceleration gain in volts per (meters per second squared).

kVAngular - The angular velocity gain in volts per (meters per second).

kAAngular - The angular acceleration gain in volts per (meters per second squared).

Returns:

Differential drive state-space model.

Throws:

IllegalArgumentException - if kVLinear <= 0, kALinear <= 0, kVAngular <= 0, or kAAngular <= 0.

See Also:

• https://github.com/wpilibsuite/allwpilib/tree/main/sysid

differentialDriveFromSysId

public static LinearSystem<N2,N2,N2> differentialDriveFromSysId(double kVLinear,
 double kALinear,
 double kVAngular,
 double kAAngular,
 double trackwidth)

Creates a differential drive state-space model from SysId constants kᵥ and kₐ in both linear {(V/(m/s), (V/(m/s²))} and angular {(V/(rad/s), (V/(rad/s²))} cases.

The states are [left velocity, right velocity], the inputs are [left voltage, right voltage], and the outputs are [left velocity, right velocity].

Parameters:

kVLinear - The linear velocity gain in volts per (meters per second).

kALinear - The linear acceleration gain in volts per (meters per second squared).

kVAngular - The angular velocity gain in volts per (radians per second).

kAAngular - The angular acceleration gain in volts per (radians per second squared).

trackwidth - The distance between the differential drive's left and right wheels, in meters.

Returns:

Differential drive state-space model.

Throws:

IllegalArgumentException - if kVLinear <= 0, kALinear <= 0, kVAngular <= 0, kAAngular <= 0, or trackwidth <= 0.

See Also:

• https://github.com/wpilibsuite/allwpilib/tree/main/sysid