Split EPS_LIN and EPS_ALT

In order to have a different precision requirement
on altitude than on horizontal positioning.

lib/Controller.js

@@ -5,9 +5,10 @@ var PID     = require('./PID');
 var EKF     = require('./EKF');
 var Camera  = require('./Camera');
 
-EPS_LIN      = 0.05; // We are ok with 5 cm precision
-EPS_ANG      = 0.05; // We are ok with 0.05 rad precision (2.5 deg)
-STABLE_DELAY = 200;  // Time in ms to wait before declaring the drone on target
+EPS_LIN      = 0.1; // We are ok with 10 cm horizontal precision
+EPS_ALT      = 0.1; // We are ok with 10 cm altitude precision
+EPS_ANG      = 0.1; // We are ok with 0.1 rad precision (5 deg)
+STABLE_DELAY = 200; // Time in ms to wait before declaring the drone on target
 
 module.exports = Controller;
 util.inherits(Controller, EventEmitter);
@@ -216,7 +217,7 @@ Controller.prototype.go = function(goal, callback) {
     // disable the controller, just in case.
     this.disable();
 
-    // If no goal given, assume an empty goal (which means the current state as goal)
+    // If no goal given, assume an empty goal
     goal = goal || {};
 
     // Normalize the yaw, to make sure we don't spin 360deg for
@@ -295,7 +296,7 @@ Controller.prototype._control = function(d) {
       ;
 
     // Check if we are within the target area
-    if ((Math.abs(ex) < EPS_LIN) && (Math.abs(ey) < EPS_LIN) && (Math.abs(ez) < EPS_LIN) && (Math.abs(eyaw) < EPS_ANG)) {
+    if ((Math.abs(ex) < EPS_LIN) && (Math.abs(ey) < EPS_LIN) && (Math.abs(ez) < EPS_ALT) && (Math.abs(eyaw) < EPS_ANG)) {
         // Have we been here before ?
         if (!this._goal.reached && this._last_ok != 0) {
             // And for long enough ?