## s_curve

Package to generate S-Curve trajectories for robotics and similar applications

### 7 releases

 new 0.1.6 May 1, 2021 Dec 10, 2020 Oct 12, 2020

#9 in Robotics

Used in cartesian_trajectories

MIT/Apache

26KB
508 lines

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.));
}
``````