Struct WaypointFollower 

pub struct WaypointFollower { /* private fields */ }

Guides a robot from waypoint to waypoint by GPS-style coordinates (carrot following).

This is the “go to that point” primitive behind a patrol route, a return-to-base, or a field pass: given where the robot is, which way it faces, and the next waypoint, it produces the twist to get there. It turns toward the target in proportion to the heading error and slows the forward speed as that error grows (by the cosine of the error), so the robot pivots toward a target behind it before driving off, rather than swinging wide. The caller holds the list of waypoints and advances to the next once Guidance::arrived is set, which keeps this allocation-free.

Examples

use pamoja_kit::{Coordinate, WaypointFollower};

// Cruise 1.5 m/s, arrive within 3 m, turn at 1.5 rad per rad of error, cap 1 rad/s.
let follower = WaypointFollower::new(1.5, 3.0, 1.5, 1.0);

// At the equator/prime meridian facing east (90 deg), with the target due east.
let here = Coordinate::new(0.0, 0.0);
let target = Coordinate::new(0.0, 0.01);
let g = follower.guide(here, 90.0, target);
assert!(g.heading_error_deg.abs() < 1e-3); // already pointed at it
assert!((g.twist.vx - 1.5).abs() < 1e-3); // so drive at cruise
assert!(!g.arrived);

Implementations

impl WaypointFollower

pub fn new( cruise: f32, arrival_m: f64, heading_gain: f32, max_angular: f32, ) -> Self

Creates a follower with the given speeds and tolerances.

Arguments

• cruise - the forward speed when pointed at the target; its magnitude is used.
• arrival_m - how close, in metres, counts as arrived; its magnitude is used.
• heading_gain - yaw rate commanded per radian of heading error; its magnitude is used.
• max_angular - the largest yaw rate to command; its magnitude is used.

Returns

The follower.

pub fn guide( &self, here: Coordinate, heading_deg: f32, target: Coordinate, ) -> Guidance

Produces the steering command from the robot’s position and heading to a target.

Arguments

• here - the robot’s current coordinate.
• heading_deg - the robot’s heading in degrees clockwise from north (a compass course).
• target - the waypoint to head toward.

Returns

The Guidance; once within the arrival radius the twist is zero and arrived is set.

Trait Implementations

impl Clone for WaypointFollower

fn clone(&self) -> WaypointFollower

Returns a duplicate of the value.

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

Performs copy-assignment from source.

impl Copy for WaypointFollower

impl Debug for WaypointFollower

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

Formats the value using the given formatter.