node-pid-controller
Simple Node.js PID controller.
Installation
``` $ npm install node-pid-controller ```Example
Let's take the example of a car cruise control. We want the car driving at 120km/h.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
let Controller = require('node-pid-controller');
let ctr = new Controller({
kp: 0.25,
ki: 0.01,
kd: 0.01,
dt: 1
});
```
You can also pass options as arguments:
```js
let ctr = new Controller(0.25, 0.01, 0.01, 1); // kp, ki, kd, dt
```
Set the target
```js ctr.setTarget(120); // 120km/h ```Get the correction
```js let correction = ctr.update(110); // 110km/h is the current speed ```Real example
Normally, you use the correction to a measure, in a closed loop. ```js let goalReached = false while (!goalReached) { let output = measureFromSomeSensor(); let input = ctr.update(output); applyInputToActuator(input); goalReached = (input === 0) ? true : false; // in the case of continuous control, you let this variable 'false' } ```Options
k_p,k_i,k_d: the PID's coefficients
dt: interval of time (in seconds) between two measures. If not provided, it will be automatically calculated.
i_max: the maximum absolute value of the integral term (optional)
