Implemented SK450 DeadCat frame support

Implemented the way to specify motor output scale which is required for SK450 DeadCat as it has asymetrical arms (front arms are longer than back ones)

src/modules/systemlib/mixer/mixer.h

@@ -441,7 +441,6 @@ private:
 	SimpleMixer operator=(const SimpleMixer&);
 };
 
-
 /**
  * Supported multirotor geometries.
  *
@@ -460,12 +459,14 @@ class __EXPORT MultirotorMixer : public Mixer
 {
 public:
 	/**
+
 	 * Precalculated rotor mix.
 	 */
 	struct Rotor {
 		float	roll_scale;	/**< scales roll for this rotor */
 		float	pitch_scale;	/**< scales pitch for this rotor */
 		float	yaw_scale;	/**< scales yaw for this rotor */
+		float	out_scale;	/**< scales total out for this rotor */
 	};
 
 	/**

src/modules/systemlib/mixer/mixer_multirotor.cpp

@@ -75,7 +75,8 @@ float constrain(float val, float min, float max)
 {
 	return (val < min) ? min : ((val > max) ? max : val);
 }
-}
+
+} // anonymous namespace
 
 MultirotorMixer::MultirotorMixer(ControlCallback control_cb,
 				 uintptr_t cb_handle,
@@ -89,6 +90,7 @@ MultirotorMixer::MultirotorMixer(ControlCallback control_cb,
 	_pitch_scale(pitch_scale),
 	_yaw_scale(yaw_scale),
 	_idle_speed(-1.0f + idle_speed * 2.0f),	/* shift to output range here to avoid runtime calculation */
+	_limits_pub(),
 	_rotor_count(_config_rotor_count[(MultirotorGeometryUnderlyingType)geometry]),
 	_rotors(_config_index[(MultirotorGeometryUnderlyingType)geometry])
 {
@@ -152,6 +154,9 @@ MultirotorMixer::from_text(Mixer::ControlCallback control_cb, uintptr_t cb_handl
 	} else if (!strcmp(geomname, "4w")) {
 		geometry = MultirotorGeometry::QUAD_WIDE;
 
+	} else if (!strcmp(geomname, "4dc")) {
+		geometry = MultirotorGeometry::QUAD_DEADCAT;
+
 	} else if (!strcmp(geomname, "6+")) {
 		geometry = MultirotorGeometry::HEX_PLUS;
 
@@ -212,6 +217,8 @@ MultirotorMixer::mix(float *outputs, unsigned space)
 			    pitch * _rotors[i].pitch_scale +
 			    thrust;
 
+		out *= _rotors[i].out_scale;
+
 		/* limit yaw if it causes outputs clipping */
 		if (out >= 0.0f && out < -yaw * _rotors[i].yaw_scale) {
 			yaw = -out / _rotors[i].yaw_scale;

src/modules/systemlib/mixer/multi_tables.py

@@ -69,6 +69,13 @@ quad_plus = [
     [ 180, CW],
 ]
 
+quad_deadcat = [
+    [  63, CCW, 1.0],
+    [-135, CCW, 0.964],
+    [ -63, CW, 1.0],
+    [ 135, CW, 0.964],
+]
+
 quad_v = [
     [  18.8, 0.4242],
     [ -18.8, 1.0],
@@ -148,13 +155,18 @@ twin_engine = [
     [-90, 0.0],
 ]
 
+
+tables = [quad_x, quad_plus, quad_v, quad_wide, quad_deadcat, hex_x, hex_plus, hex_cox, octa_x, octa_plus, octa_cox, twin_engine]
+
 def variableName(variable):
     for variableName, value in list(globals().items()):
         if value is variable:
             return variableName
 
-tables = [quad_x, quad_plus, quad_v, quad_wide, hex_x, hex_plus, hex_cox, octa_x, octa_plus, octa_cox, twin_engine]
-
+def unpackScales(scalesList):
+    if len(scalesList) == 2:
+        scalesList += [1.0] #Add thrust scale
+    return scalesList
 
 def printEnum():
     print("enum class MultirotorGeometry : MultirotorGeometryUnderlyingType {")
@@ -167,10 +179,11 @@ def printEnum():
 def printScaleTables():
     for table in tables:
         print("const MultirotorMixer::Rotor _config_{}[] = {{".format(variableName(table)))
-        for (angle, yawScale) in table:
+        for row in table:
+            angle, yawScale, thrustScale = unpackScales(row)
             rollScale = rcos(angle + 90)
             pitchScale = rcos(angle)
-            print("\t{{ {:9f}, {:9f}, {:9f} }},".format(rollScale, pitchScale, yawScale))
+            print("\t{{ {:9f}, {:9f}, {:9f}, {:9f} }},".format(rollScale, pitchScale, yawScale, thrustScale))
         print("};\n")
 
 def printScaleTablesIndex():