PD control

by jason870509

HTML

<div id="info">PD Control
  <br>Press U or D to move dot<br>
  

KP<input type=range min=50 max=1000 id='kp'> <p id='kptext'>100</p>
<br>
KI<input type=range min=50 max=350 id='ki'> <p id='kitext'>20</p><br>
KD<input type=range min=0 max=100 id='kd'> <p id='kdtext'>100</p><br>
</div>
<script src="https://cdnjs.cloudflare.com/ajax/libs/three.js/84/three.min.js"></script>
<script src="https://jyunming-chen.github.io/tutsplus/js/KeyboardState.js"></script>
<script src="https://code.jquery.com/jquery-2.1.4.min.js"></script>

CSS

#info {
  position: absolute;
  top: 0px;
  width: 100%;
  padding: 10px;
  text-align: center;
  color: #ffff00
}

body {
  overflow: hidden;
}

JavaScript

var camera, scene, renderer;
var point;
var keyboard = new KeyboardState();
/////////////////////
var KP = 100;
var KD = 20;
var KI = 100
var yy, vv;
var gravity = true;
var yref = -2;
var integral = 0
$('#kp').change( function() {
	KP = $(this).val();
  $('#kptext').text(KP);
});
$('#kd').change( function() {
	KD = $(this).val();
  $('#kdtext').text(KD);
});
$('#ki').change( function() {
	KI = $(this).val();
  $('#kitext').text(KI);
});
init();
animate();

function init() {
  renderer = new THREE.WebGLRenderer({
    antialias: true
  });

  renderer.setSize(window.innerWidth, window.innerHeight);
  renderer.setClearColor(0x888888);
  document.body.appendChild(renderer.domElement);

  scene = new THREE.Scene();
  camera = new THREE.OrthographicCamera(-10, 10, 10, -10, -10, 1000);
 
	//////////////////////////////////////////////////
  var geometry = new THREE.Geometry();
  geometry.vertices.push(
    new THREE.Vector3(-4, 2, 0),
    new THREE.Vector3(4, 2, 0));

  var border = new THREE.Line(geometry, new THREE.LineBasicMaterial({
    color: 0x0000ff
  }));
  var border2 = border.clone();
  border2.position.y = -7;
  border.position.y = 3
  scene.add (border2)
  scene.add(border);

  point = new THREE.Mesh(new THREE.CircleGeometry(0.4, 10),
    new THREE.MeshBasicMaterial({
      color: 0xff0000,
    }));
  scene.add(point);

	yy = 0;
  vv = 0;
}

function feedbackForce (dt) {
  let error = yref - yy;
  integral += error*dt;
  

  let omega = KP*error + KI*integral + KD*(-vv);

	//omega = Math.clamp (omega, 0, 100);
	//console.log (error.toFixed(1) + ' + ' + omega.toFixed(1))
  
  return omega;
}

function animate() {
	let dt = 0.01;
	var f = feedbackForce(dt);
	if (gravity) 
  	f += (-70);
    
  // Euler's method  
  
  vv += f/7*dt;
  yy += vv*dt

	point.position.y = yy;
  
  keyboard.update();
  if (keyboard.down('U')) {
  	yref = 5;
  } else if (keyboard.down('D')) {
  	yref = -5
  }
	requestAnimationFrame(animate);
  render();
}

function render() {
 ...