Diff: PID.h

Revision:

0:7e5fe0bea780

Child:

5:43a44c2880a3

diff -r 000000000000 -r 7e5fe0bea780 PID.h
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/PID.h	Thu Jun 06 18:58:08 2013 +0000
@@ -0,0 +1,58 @@
+/** PID.h */
+
+#ifndef UWBQuad__PID__h
+#define UWBQuad__PID__h
+
+/**
+ * UWB Quadcopter project
+ *
+ * Implementation of the Proportional Integral Derivative
+ * control system for quadcopter stabilization.
+ * http://nicisdigital.wordpress.com/2011/06/27/proportional-integral-derivative-pid-controller/
+ *
+ * @author UWB Quadcopter group
+ */
+class PID
+{
+
+public:
+    /**
+     * Initialize the controller.
+     *
+     * @param proportionalGain Tuning value for adjusting the copter
+     *                          towards a target position.
+     * @param integralGain Tuning value for compensating for
+     *                      environment imperfections that provide
+                            resistance such as friction.
+     * @param derivativeGain Tuning value for compensating for
+     *                          environment imperfections that cause
+     *                          the system to overshoot the target,
+     *                          such as momentum.
+     * @param windupGainGuard Cap for the maximum error value.
+     */
+    PID(const float, const float, const float, const float);
+
+    /**
+     * Determine how to correct the system to the desired position.
+     *
+     * @param currentPosition The current vector of the system.
+     * @param targetPosition The desired vector of the system.
+     * @param dt The change in time since the last adjustment.
+     *              (time determined by caller,
+     *               eg. PID can be switched off for manual control)
+     * @return Adjustment to apply to the motors.
+     */
+    float correct(const float, const float, const float);
+
+private:
+    const float proportionalGain;
+    const float integralGain;
+    const float derivativeGain;
+    const float windupGainGuard;
+
+    float previousError;
+    float integralError;
+
+};
+
+#endif