Struct RamseteController 

pub struct RamseteController { /* private fields */ }

RAMSETE controller configuration and calculation.

The RAMSETE controller is a nonlinear trajectory tracker that computes velocity commands to follow a reference trajectory while correcting for position and heading errors.

Parameters

• b: Convergence gain that determines how aggressively the controller corrects lateral and heading errors. Higher values = faster convergence but potentially more oscillation. Typical value: 2.0
• zeta: Damping ratio similar to a second-order system. Higher values reduce oscillation. Typical value: 0.7
• epsilon: Small-angle threshold for sinc function to avoid division by zero. Default: 1e-6

Implementations

impl RamseteController

pub fn new() -> Self

Creates a RAMSETE controller with zero gains.

Use set to configure the tuning parameters.

Example

let ramsete = RamseteController::new().set(2.0, 0.7);

pub fn set(self, b: f64, zeta: f64) -> Self

Sets the RAMSETE tuning parameters.

Arguments

• b - Convergence gain (typical: 2.0)
• zeta - Damping ratio (typical: 0.7)

Returns

A new controller with the specified gains.

pub fn with_epsilon(self, epsilon: f64) -> Self

Sets the small-angle epsilon for the sinc function.

When the heading error is smaller than epsilon, sinc(theta) returns 1.0 to avoid numerical instability from dividing by near-zero values.

Arguments

• epsilon - Small-angle threshold (default: 1e-6)

pub fn calculate( &self, current: Pose, reference: RamseteReference, ) -> (f64, f64)

Computes the linear and angular velocity commands.

Arguments

• current - The robot’s current pose
• reference - The desired trajectory reference point

Returns

A tuple (v, w) where:

• v is the commanded linear velocity in m/s
• w is the commanded angular velocity in rad/s

Algorithm

1. Computes errors in the robot frame (e_x, e_y, e_theta)
2. Calculates adaptive gain k based on reference velocities
3. Applies RAMSETE equations to compute corrected velocities

Trait Implementations

impl Clone for RamseteController

fn clone(&self) -> RamseteController

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Debug for RamseteController

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

Formats the value using the given formatter.

impl Copy for RamseteController