s_curve: A Rust repository from SungChiCHIANG

A library to compute S-Curve trajectories. It can be used to generate motion profiles for robotics.

What is an S-Curve?

An S-Curve is a trajectory which is constrained to maximum jerk, acceleration and velocity. An S-Curve consists of 7 phases:

constant maximum jerk until the desired acceleration is reached
constant maximum acceleration phase
constant minimum jerk until the desired velocity is reached with an acceleration of zero
constant velocity phase
constant minimum jerk until the minimum acceleration is reached
constant minimum acceleration phase
constant maximum jerk until the acceleration is zero and the desired position and end velocity is reached

In the picture below you can see an S-Curve Profile which goes from Position 0 to position 10 within 5.5 seconds with a start and end velocity of 0 , a maximum jerk of 3, a maximum acceleration of 2 and a maximum velocity of 3.

Example

use s_curve::*;
let constraints = SCurveConstraints {
            max_jerk: 3.,
            max_acceleration: 2.0,
            max_velocity: 3.};
let  start_conditions = SCurveStartConditions {
    q0: 0., // start position
    q1: 10., // end position
    v0: 0., // start velocity
    v1: 0. // end velocity
};
let input  =  SCurveInput{constraints, start_conditions};
let (params,s_curve) = s_curve_generator( & input,Derivative::Velocity);
for i in 0..101 {
    println!("{}", s_curve(i as f64 * params.time_intervals.total_duration() / 100.));
}

SungChiCHIANG/s_curve

What is an S-Curve?

Example

License