Ecosyste.ms: Awesome
An open API service indexing awesome lists of open source software.
https://github.com/rawify/stewart.js
Inverse kinematics for Stewart Platforms written in JavaScript
https://github.com/rawify/stewart.js
animation javascript quaternion simulation stewart-platform
Last synced: 1 day ago
JSON representation
Inverse kinematics for Stewart Platforms written in JavaScript
- Host: GitHub
- URL: https://github.com/rawify/stewart.js
- Owner: rawify
- License: mit
- Created: 2019-02-16T20:09:30.000Z (almost 6 years ago)
- Default Branch: main
- Last Pushed: 2024-10-09T07:13:18.000Z (3 months ago)
- Last Synced: 2025-01-09T13:29:09.044Z (9 days ago)
- Topics: animation, javascript, quaternion, simulation, stewart-platform
- Language: JavaScript
- Homepage: https://raw.org/research/inverse-kinematics-of-a-stewart-platform/
- Size: 125 KB
- Stars: 35
- Watchers: 3
- Forks: 16
- Open Issues: 0
-
Metadata Files:
- Readme: README.md
- License: LICENSE
Awesome Lists containing this project
README
# Stewart Platform
[](https://npmjs.org/package/stewart "View this project on npm")
[](http://opensource.org/licenses/MIT)
[Stewart Platforms](https://raw.org/research/inverse-kinematics-of-a-stewart-platform/) are used for motion platforms with six dimensions of freedom. With this library you can simulate Stewart Platforms as well as use the calculated angles to drive a real platform.
## Visualization
The code can run headless, but to set up all parameters properly, a visualization of the platform can help a lot. To do so, we use p5.js and quaternion.js
```js
var sketch = function(p) {
p.setup = function() {
p.createCanvas(600, 600, p.WEBGL);
p.camera(100.0, -290.0, (p.height / 2.0) / Math.tan(Math.PI / 6),
0.0, 0.0, 0.0,
0.0, 1.0, 0.0);
platform = new Stewart;
platform.initHexagonal(/*{ options }*/);
};
p.draw = function() {
p.background(255);
p.push();
p.translate(50, -70, 200);
p.rotateX(Math.PI / 2); // Work in correct X-Y-Z plane
// Set correct position where to drive to
platform.update([0, 0, 0], Quaternion.ONE);
// Draw the updated platform
platform.draw(p);
// Send to servos
// platform.getServoAngles();
p.pop();
};
};
new p5(sketch, 'canvas');
```
## Examples
In the examples folder are use cases documented.
### Default
The default example can be controlled via key presses on letters from a-z on the keyboard. Not all letters have a function.
Here is a list:
- q: Skewed square
- w: wobble
- e: eight
- r: rotate
- t: tilt
- y: lissajous
- m: mouse control
- g: Gamepad control, using Gamepad Web API
- b: Simulation of breath
- h: Helical animation
### SVG Plotter
SVG paths are parsed and used for motion commads. This way SVG images can be plotted with a Stewart platform by attaching a pen:
### LeapMotion
The hand tracking device LeapMotion can be read via JavaScript using the leapjs package. The example uses the LeapMotion to use the hand position and orienttion as input for the platform.
## Options
The platform visualization is meant to draw a platform in milimeter. When you work headless, the unit does not matter. The following options are available:
### rodLength
The length of the rod attached to the servo horn and the platform. Default=130
### hornLength
The length of the servo horn attached to the motor shaft and the rod. Default=50
### hornDirection
The horn direction indicates if the servo horn is rotated to the left or to the right. 0=right, 1=left, Default=0
### servoRange
A valid range for the servo motors to rotate. A typical low-cost servo has 180° working space. The value is an array [minAngle, maxAngle]. Default=[-pi/2, pi/2]
### servoRangeVisible
A boolean if the servo range should be visible in the drawing. Default=false
### baseRadius + baseRadiusOuter
When a hexagonal stewart platform is used, the `baseRadiusOuter` is used to draw the base plate in accordance to the [description](https://raw.org/research/inverse-kinematics-of-a-stewart-platform/).
### platformRadius + platformRadiusOuter
When a hexagonal stewart platform is used, the `platformRadiusOuter` is used to draw the platform plate in accordance to the [description](https://raw.org/research/inverse-kinematics-of-a-stewart-platform/).
### shaftDistance + ankerDistance
For a circular platform this indicates the radial distance of pairs of rod ankers between the shafts on the base plate and the platform plate. For hexagonal platforms this indicates the distance from the middle of a side to attach the rod ankers. Default=20
### platformTurn
A boolean for hexagonal platforms to indicate if the platform shall look into the same direction as the base plate. Default=true
## Installation
Installing Stewart.js is as easy as cloning this repo or use one of the following command:
```
npm install stewart
```
## Building the library
After cloning the Git repository run:
```
npm install
npm run build
```
## Copyright and Licensing
Copyright (c) 2024, [Robert Eisele](https://raw.org/)
Licensed under the MIT license.