AR_AttitudeControl: allow filter to be zero

Also increase default filter to 50hz

libraries/APM_Control/AR_AttitudeControl.cpp

@@ -59,7 +59,7 @@ const AP_Param::GroupInfo AR_AttitudeControl::var_info[] = {
     // @Param: _STR_RAT_FILT
     // @DisplayName: Steering control filter frequency
     // @Description: Steering control input filter.  Lower values reduce noise but add delay.
-    // @Range: 1.000 100.000
+    // @Range: 0.000 100.000
     // @Increment: 0.1
     // @Units: Hz
     // @User: Standard
@@ -102,7 +102,7 @@ const AP_Param::GroupInfo AR_AttitudeControl::var_info[] = {
     // @Param: _SPEED_FILT
     // @DisplayName: Speed control filter frequency
     // @Description: Speed control input filter.  Lower values reduce noise but add delay.
-    // @Range: 1.000 100.000
+    // @Range: 0.000 100.000
     // @Increment: 0.1
     // @Units: Hz
     // @User: Standard

libraries/APM_Control/AR_AttitudeControl.h

@@ -12,12 +12,12 @@
 #define AR_ATTCONTROL_STEER_RATE_I      0.50f
 #define AR_ATTCONTROL_STEER_RATE_IMAX   1.00f
 #define AR_ATTCONTROL_STEER_RATE_D      0.00f
-#define AR_ATTCONTROL_STEER_RATE_FILT   5.00f
+#define AR_ATTCONTROL_STEER_RATE_FILT   50.00f
 #define AR_ATTCONTROL_THR_SPEED_P       0.20f
 #define AR_ATTCONTROL_THR_SPEED_I       0.20f
 #define AR_ATTCONTROL_THR_SPEED_IMAX    1.00f
 #define AR_ATTCONTROL_THR_SPEED_D       0.00f
-#define AR_ATTCONTROL_THR_SPEED_FILT    5.00f
+#define AR_ATTCONTROL_THR_SPEED_FILT    50.00f
 #define AR_ATTCONTROL_DT                0.02f
 #define AR_ATTCONTROL_TIMEOUT_MS        200