node-pid-controller - npm Package Compare versions

Comparing version 0.0.3 to 0.1.1

lib/index.js

		/**
		* PID Controller.
		*/
		var Controller = function(k_p, k_i, k_d) {
		this.k_p = k_p \|\| 1;
		var Controller = function(k_p, k_i, k_d, dt) {
		// PID constants
		this.k_p = (typeof k_p === 'number') ? k_p : 1;
		this.k_i = k_i \|\| 0;
		this.k_d = k_d \|\| 0;

		// Interval of time between two updates
		// If not set, it will be automatically calculated
		this.dt = dt \|\| 0;

		this.sumError = 0;
		@@ -20,8 +25,23 @@ this.lastError = 0;

		Controller.prototype.update = function(current_value) {
		this.current_value = current_value;
		Controller.prototype.update = function(currentValue) {
		this.currentValue = currentValue;

		var error = (this.target - this.current_value);
		this.sumError = this.sumError + error;
		var dError = error - this.lastError;
		// Calculate dt
		var dt = this.dt;
		if (!dt) {
		var currentTime = Date.now();
		if (this.lastTime === 0) { // First time update() is called
		dt = 0;
		} else {
		dt = (currentTime - this.lastTime) / 1000; // in seconds
		}
		this.lastTime = currentTime;
		}
		if (typeof dt !== 'number' \|\| dt === 0) {
		dt = 1;
		}

		var error = (this.target - this.currentValue);
		this.sumError = this.sumError + error*dt;
		var dError = (error - this.lastError)/dt;
		this.lastError = error;
		@@ -32,2 +52,8 @@

		module.exports = Controller;
		Controller.prototype.reset = function() {
		this.sumError = 0;
		this.lastError = 0;
		this.lastTime = 0;
		};

		module.exports = Controller;

package.json

		{
		"name": "node-pid-controller",
		"version": "0.0.3",
		"version": "0.1.1",
		"description": "Node.js PID controller",
		@@ -5,0 +5,0 @@ "keywords": [

README.md

		@@ -15,5 +15,6 @@ # node-pid-controller
		### Create a Controller instance
		`k_p`, `k_i` and `k_d` are the proportional, integral and derivative terms. `dt` is the interval of time between two measures. If not set, it will be automatically calculated.
		```js
		var Controller = require('node-pid-controller');
		var ctr = new Controller(0.25, 0.01, 0.01); // k_p, k_i, k_d
		var ctr = new Controller(0.25, 0.01, 0.01, 1); // k_p, k_i, k_d, dt
		```
		@@ -50,2 +51,2 @@

		Philmod <philippe.modard@gmail.com>
		Philmod <philippe.modard@gmail.com>

test/index.js

		@@ -15,9 +15,9 @@ /**

		var k_p = 0.5
		, k_i = 0.1
		, k_d = 0.2
		;
		var k_p = 0.5,
		k_i = 0.1,
		k_d = 0.2,
		dt = 1;

		// Create the controller
		var ctr = new Controller(k_p, k_i, k_d);
		var ctr = new Controller(k_p, k_i, k_d, dt);

		@@ -41,3 +41,23 @@ it('should have set the coefficient', function() {
		});

		it('should reset the controller', function(){
		ctr.reset();
		ctr.sumError.should.equal(0);
		ctr.lastError.should.equal(0);
		ctr.lastTime.should.equal(0);
		});

		it('should return the correction for the given update interval', function(){
		ctr.dt = 2; // 2 seconds between updates
		var correction = ctr.update(115);
		correction.should.equal(4);
		});

		it('should return a null correction', function(){
		var ctr = new Controller(0, 0, 0);
		ctr.setTarget(120);
		var correction = ctr.update(110);
		correction.should.equal(0);
		});

		});

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