diff options
-rw-r--r-- | src/modules/systemlib/mixer/mixer_multirotor.cpp | 89 |
1 files changed, 49 insertions, 40 deletions
diff --git a/src/modules/systemlib/mixer/mixer_multirotor.cpp b/src/modules/systemlib/mixer/mixer_multirotor.cpp index bf77795d5..8568f9e60 100644 --- a/src/modules/systemlib/mixer/mixer_multirotor.cpp +++ b/src/modules/systemlib/mixer/mixer_multirotor.cpp @@ -67,6 +67,11 @@ namespace { +float constrain(float val, float min, float max) +{ + return (val < min) ? min : ((val > max) ? max : val); +} + /* * These tables automatically generated by multi_tables - do not edit. */ @@ -276,62 +281,66 @@ MultirotorMixer::from_text(Mixer::ControlCallback control_cb, uintptr_t cb_handl unsigned MultirotorMixer::mix(float *outputs, unsigned space) { - float roll = get_control(0, 0) * _roll_scale; + float roll = constrain(get_control(0, 0) * _roll_scale, -1.0f, 1.0f); //lowsyslog("roll: %d, get_control0: %d, %d\n", (int)(roll), (int)(get_control(0, 0)), (int)(_roll_scale)); - float pitch = get_control(0, 1) * _pitch_scale; - float yaw = get_control(0, 2) * _yaw_scale; - float thrust = get_control(0, 3); + float pitch = constrain(get_control(0, 1) * _pitch_scale, -1.0f, 1.0f); + float yaw = constrain(get_control(0, 2) * _yaw_scale, -1.0f, 1.0f); + float thrust = constrain(get_control(0, 3), 0.0f, 1.0f); //lowsyslog("thrust: %d, get_control3: %d\n", (int)(thrust), (int)(get_control(0, 3))); - float max = 0.0f; - float fixup_scale; + float min_out = 0.0f; + float max_out = 0.0f; + float scale_yaw = 1.0f; - /* use an output factor to prevent too strong control signals at low throttle */ - float min_thrust = 0.05f; - float max_thrust = 1.0f; - float startpoint_full_control = 0.40f; - float output_factor; + /* perform initial mix pass yielding unbounded outputs, ignore yaw */ + for (unsigned i = 0; i < _rotor_count; i++) { + float out = roll * _rotors[i].roll_scale + + pitch * _rotors[i].pitch_scale + + thrust; - /* keep roll, pitch and yaw control to 0 below min thrust */ - if (thrust <= min_thrust) { - output_factor = 0.0f; - /* linearly increase the output factor from 0 to 1 between min_thrust and startpoint_full_control */ + /* limit yaw if it causes outputs clipping */ + if (out >= 0.0f && out < -yaw * _rotors[i].yaw_scale) { + yaw = -out / _rotors[i].yaw_scale; + } - } else if (thrust < startpoint_full_control && thrust > min_thrust) { - output_factor = (thrust / max_thrust) / (startpoint_full_control - min_thrust); - /* and then stay at full control */ + /* calculate min and max output values */ + if (out < min_out) { + min_out = out; + } + if (out > max_out) { + max_out = out; + } - } else { - output_factor = max_thrust; + outputs[i] = out; } - roll *= output_factor; - pitch *= output_factor; - yaw *= output_factor; - + /* scale down roll/pitch controls if some outputs are negative, don't add yaw, keep total thrust */ + if (min_out < 0.0) { + float scale_in = thrust / (thrust - min_out); - /* perform initial mix pass yielding un-bounded outputs */ - for (unsigned i = 0; i < _rotor_count; i++) { - float tmp = roll * _rotors[i].roll_scale + - pitch * _rotors[i].pitch_scale + - yaw * _rotors[i].yaw_scale + - thrust; - - if (tmp > max) - max = tmp; + /* mix again with adjusted controls */ + for (unsigned i = 0; i < _rotor_count; i++) { + outputs[i] = scale_in * (roll * _rotors[i].roll_scale + pitch * _rotors[i].pitch_scale) + thrust; + } - outputs[i] = tmp; + } else { + /* roll/pitch mixed without limiting, add yaw control */ + for (unsigned i = 0; i < _rotor_count; i++) { + outputs[i] += yaw * _rotors[i].yaw_scale; + } } - /* scale values into the -1.0 - 1.0 range */ - if (max > 1.0f) { - fixup_scale = 2.0f / max; + /* scale down all outputs if some outputs are too large, reduce total thrust */ + float scale_out; + if (max_out > 1.0f) { + scale_out = 1.0f / max_out; } else { - fixup_scale = 2.0f; + scale_out = 1.0f; } - for (unsigned i = 0; i < _rotor_count; i++) - outputs[i] = -1.0f + (outputs[i] * fixup_scale); + for (unsigned i = 0; i < _rotor_count; i++) { + outputs[i] = -1.0f + (outputs[i] * 2 * scale_out); + } /* ensure outputs are out of the deadband */ for (unsigned i = 0; i < _rotor_count; i++) |