APM_Control: move reliance from IMU to INS

libraries/APM_Control/AP_YawController.cpp

@@ -27,7 +27,7 @@ int32_t AP_YawController::get_servo_out(float scaler, bool stick_movement)
 	}
 	_last_t = tnow;
 	
-	if(_imu == NULL) { // can't control without a reference
+	if(_ins == NULL) { // can't control without a reference
 		return 0; 
 	}
 	
@@ -44,7 +44,7 @@ int32_t AP_YawController::get_servo_out(float scaler, bool stick_movement)
 	}
 	_stick_movement = stick_movement;
 
-	Vector3f accels = _imu->get_accel();
+	Vector3f accels = _ins->get_accel();
 	
 	// I didn't pull 512 out of a hat - it is a (very) loose approximation of 100*ToDeg(asin(-accels.y/9.81))
 	// which, with a P of 1.0, would mean that your rudder angle would be equal to your roll angle when

libraries/APM_Control/AP_YawController.h

@@ -12,7 +12,7 @@ class AP_YawController {
 public:                      
 	void set_ahrs(AP_AHRS *ahrs) { 
 		_ahrs = ahrs; 
-		_imu = _ahrs->get_imu();
+		_ins = _ahrs->get_ins();
 	}
 
 	int32_t get_servo_out(float scaler = 1.0, bool stick_movement = false);
@@ -34,7 +34,7 @@ private:
 	uint32_t _freeze_start_time;
 
 	AP_AHRS *_ahrs;
-	IMU *_imu;
+	AP_InertialSensor *_ins;
 
 	// Low pass filter cut frequency for derivative calculation.
 	// FCUT macro computes a frequency cut based on an acceptable delay.