Struct Actuator 

pub struct Actuator {
    pub name: String,
    pub joint_name: String,
    pub joint_idx: usize,
    pub gear: f64,
    pub ctrl_range: Option<[f64; 2]>,
    pub gain: f64,
    pub bias_q: f64,
    pub bias_v: f64,
    pub force_range: Option<[f64; 2]>,
}

An actuator attached to a joint.

Follows MuJoCo’s affine actuator model: the generalized force applied to the joint’s first DOF is

f = gear * (gain * ctrl + bias_q * q + bias_v * v)

which expresses <motor>, <position>, <velocity> and the affine subset of <general> with one parameter set, so downstream code never branches on actuator type. A plain motor is gain = 1, bias_q = bias_v = 0, for which this reduces to gear * clamp(ctrl).

Fields

name: String

Actuator name, as declared in the source model.

joint_name: String

Name of the joint this actuator drives.

joint_idx: usize

Index into Model::joints of the driven joint.

gear: f64

Gear ratio applied to the control signal to produce joint torque.

ctrl_range: Option<[f64; 2]>

Optional [lo, hi] clamp on the control signal, before gear.

gain: f64

Coefficient on ctrl. 1 for a motor, kp for a position servo.

bias_q: f64

Coefficient on joint position. -kp for a position servo, else 0.

bias_v: f64

Coefficient on joint velocity. -kv for a servo, else 0.

force_range: Option<[f64; 2]>

Force limits applied after the affine law, or None if unlimited.

Implementations

impl Actuator

pub fn clamp_ctrl(&self, ctrl: f64) -> f64

Clamp a raw control value to this actuator’s control range.

pub fn force(&self, ctrl: f64) -> f64

Generalized force produced by this actuator for a raw control value, ignoring any state feedback.

Correct for motors. Position and velocity servos additionally depend on q and v; use Self::force_at for those.

pub fn force_at(&self, ctrl: f64, q: f64, v: f64) -> f64

Evaluate the full affine actuator law at the joint’s current state.

pub fn motor(name: &str, joint_name: &str, joint_idx: usize, gear: f64) -> Self

A direct-torque motor: f = gear * ctrl.

pub fn position( name: &str, joint_name: &str, joint_idx: usize, gear: f64, kp: f64, kv: f64, ) -> Self

A position servo: f = gear * (kp * (ctrl - q) - kv * v).

pub fn velocity( name: &str, joint_name: &str, joint_idx: usize, gear: f64, kv: f64, ) -> Self

A velocity servo: f = gear * kv * (ctrl - v).

Trait Implementations

impl Clone for Actuator

fn clone(&self) -> Actuator

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl Debug for Actuator

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for Actuator

fn default() -> Self

Returns the “default value” for a type.