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