Diff: Actuators/Steering/Steering.h

Revision:

15:01fb4916a5cd

Parent:

2:fbc6e3cf3ed8

--- a/Actuators/Steering/Steering.h	Thu Nov 29 16:59:39 2018 +0000
+++ b/Actuators/Steering/Steering.h	Thu Nov 29 17:11:34 2018 +0000
@@ -2,6 +2,9 @@
 #define __STEERING_H
 
 #include "globals.h"
+#include "devices.h"
+#include "Servo.h"
+#include "Config.h"
 
 /** A class for managing steering angle calculations based on current and desired heading
  *  and specified intercept distance along the new path.  
@@ -11,19 +14,55 @@
 class Steering
 {
   public:
-    /** create a new steering calculator
+    /** create a new steering calculator */
+    Steering(PinName pin);
+
+    /** Initalize steering actuator (servo)
+     *
+     */
+    void initSteering(void);
+
+
+    /** Set the track width (left to right contact patch distance)
      *
-     * @param wheelbase vehicle wheelbase
-     * @param track vehicle track width
-     * @param intercept new course intercept distance
+     * @param track is the vehicle track width
      */
-    Steering(float wheelbase, float track);
+    void setTrack(float track);
+
+
+    /** Set the wheelbase (front to rear axle distance)
+     *
+     * @param wheelbase is the vehicle wheelbase
+     */
+    void setWheelbase(float wheelbase);
+
 
     /** set intercept distance
      * @param intercept distance along new course at which turn arc will intercept
      */
     void setIntercept(float intercept);
 
+
+    /** set steering scale factor to convert between steering angle and servo output
+     * @param scale is the scale factor
+     */
+    void setScale(float scale);
+
+
+    /** Convert steerAngle to servo value
+     *
+     * Testing determined near linear conversion between servo ms setting and steering angle
+     * up to ~20*.
+     *
+     * @param steerAngle is the steering angle, measured at front wheels, averaged
+     */
+    void setSteering(float steerAngle);
+
+
+    /**  Shorthand for the write function */
+    float operator= (float steerAngle);
+
+
     /** convert course change to average steering angle
      * assumes Ackerman steering, with track and wheelbase
      * and course intercept distance specified.
@@ -35,6 +74,7 @@
      */ 
     float calcSA(float theta);
 
+
     /** convert course change to average steering angle
      * assumes Ackerman steering, with track and wheelbase
      * and course intercept distance specified. Also, |radius| of turn is limited to limit
@@ -47,28 +87,42 @@
      */ 
     float calcSA(float theta, float limit);
 
+
     /** compute steering angle based on pure pursuit algorithm
      */
     float purePursuitSA(float hdg, float Bx, float By, float Ax, float Ay, float Cx, float Cy);
     
+
     /** compute steering angle based on a simpler path pursuit variant of pure pursuit
      */
     float pathPursuitSA(float hdg, float Bx, float By, float Ax, float Ay, float Cx, float Cy);
 
+
     /** Compute cross track error given last waypoint, next waypoint, and robot coordinates
      * @returns cross track error
      */
     float crossTrack(float Bx, float By, float Ax, float Ay, float Cx, float Cy);
-    
-  private:
+
 
-    inline static float angle_radians(float deg) {return (PI/180.0)*deg;}
+    /** Convert degrees to radians
+     * @param deg degrees to convert
+     * @return radians
+     */
+    inline static float toRadians(float deg) {return (PI/180.0)*deg;}
+
 
-    inline static float angle_degrees(float rad) {return (180/PI)*rad;}
+    /** Convert radians to degrees
+     * @param rad radians to convert
+     * @return degrees
+     */
+    inline static float toDegrees(float rad) {return (180/PI)*rad;}
 
-    float _wheelbase;
-    float _track;
-    float _intercept;
+  private:
+    Servo _steering;                // Steering Servo
+    float _scale;                   // Steering scale factor
+    float _track;                   // vehicle track used for steering intercept calc
+    float _wheelbase;               // vehicle wheelbase used for steering intercept calc
+    float _intercept;               // circle intercept distance
 };
 
-#endif
\ No newline at end of file
+#endif