marcelxpfeifer / rover

Library for the simulation of a rover including a simple top-down visualization.

About The Project

Simple simulation for a program-driven vehicle with a top-down visualization.

Motivation

• Testing of simple navigation routines
• Preparation of IOT projects with autonomous vehicles
• JavaScript/Typescript only

Built With

The rover simulation uses the following 3rd party libraries:

• Geodesy
• P2

Special thanks to Chris Veness!

Installation

To use the simulation create a new web project including a bundler like Webpack and install the package from github.

with npm

npm install github:davidlinner/rover

Usage

Basic example:

import {Simulation} from 'rover';

// Create a simple control function which only tells the engines to go forward, left a bit slower, so we drive in a circle
// The control function will be called periodically in the control loop 
const loop = ({location, heading, clock}, {engines}) => {    
    return {
        engines: [0.5,0.8]
    }
}

// Create a new simulation
const simulation = new Simulation({
    // add above loop 
    loop,

    // define the origin offset of the rover on the planet,
    origin: {
        latitude:52.477050353132384,
        longitude:13.395281227289209
    },

    // select the DOM element the visualization canvas should be appended to as child
    element: document.querySelector('main'),

    // define a list of static points to be rendered in the visualization (nice for waypoints)
    locationsOfInterest: [{
        latitude: 52.47880703639255,
        longitude: 13.395281227289209,
        label: 'A'
    }],
  
    // set rending options like size and colors
    // consult the API docs for all switches and params 
    renderingOptions: {
        width: 500, // width of created canvas
        height: 500 // height of created canvas
    }
});

// as soon as the simulation is created the visualization is rendered,
// but have to explicitely start the control loop
simulation.start();

Additionally, you can configure a more realistic behavior for the simulation by setting the physicalContraints property. Two constraint collections, AUTHENTICITY_LEVEL0 and AUTHENTICITY_LEVEL1, are predefined, while the first means no error at all. AUTHENTICITY_LEVEL1, in contrast, adds random measurement errors to heading and location and a little, random unbalance to the two engines. Since the random seeds are different for each run of the simulation error correction has to be added to the control loop.

Example with some environmental error:

// Import main Simulation class and error factory function  
import {Simulation, AUTHENTICITY_LEVEL1} from 'rover';

// Create a simple control function which should make the vehicle move straight forward 
const loop = ({location, heading, clock}, {engines}) => {    
    return {
        engines: [0.8,0.8]
    }
}

// Create a new simulation
const simulation = new Simulation({
    // add above loop
    loop,

    // define the origin offset of the rover on the planet,
    origin: {
        latitude:52.477050353132384,
        longitude:13.395281227289209
    },

    // select the DOM element the visualization canvas should be appended to as child
    element: document.querySelector('main'),
  
    // Set the factory function for physical constraints
    // Predefined constraints are AUTHENTICITY_LEVEL0 and AUTHENTICITY_LEVEL1, while first means no error   
    physicalConstraints: AUTHENTICITY_LEVEL1
});

// as soon as the simulation is created the visualization is rendered,
// but have to explicitely start the control loop
simulation.start();

Please consult the API Docs for details.

• API Docs

License

Distributed under the MIT License.