/**************************************************************************** * * Copyright (c) 2015 PX4 Development Team. All rights reserved. * * Redistribution and use in source and binary forms, with or without * modification, are permitted provided that the following conditions * are met: * * 1. Redistributions of source code must retain the above copyright * notice, this list of conditions and the following disclaimer. * 2. Redistributions in binary form must reproduce the above copyright * notice, this list of conditions and the following disclaimer in * the documentation and/or other materials provided with the * distribution. * 3. Neither the name PX4 nor the names of its contributors may be * used to endorse or promote products derived from this software * without specific prior written permission. * * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE * POSSIBILITY OF SUCH DAMAGE. * ****************************************************************************/ /** * @file standard.cpp * * @author Simon Wilks * @author Roman Bapst * @author Andreas Antener * @author Sander Smeets * */ #include "standard.h" #include "vtol_att_control_main.h" #include using matrix::wrap_pi; Standard::Standard(VtolAttitudeControl *attc) : VtolType(attc), _pusher_throttle(0.0f), _reverse_output(0.0f), _airspeed_trans_blend_margin(0.0f) { _vtol_schedule.flight_mode = MC_MODE; _vtol_schedule.transition_start = 0; _pusher_active = false; _mc_roll_weight = 1.0f; _mc_pitch_weight = 1.0f; _mc_yaw_weight = 1.0f; _mc_throttle_weight = 1.0f; _params_handles_standard.pusher_ramp_dt = param_find("VT_PSHER_RMP_DT"); _params_handles_standard.back_trans_ramp = param_find("VT_B_TRANS_RAMP"); _params_handles_standard.down_pitch_max = param_find("VT_DWN_PITCH_MAX"); _params_handles_standard.forward_thrust_scale = param_find("VT_FWD_THRUST_SC"); _params_handles_standard.pitch_setpoint_offset = param_find("FW_PSP_OFF"); _params_handles_standard.reverse_output = param_find("VT_B_REV_OUT"); _params_handles_standard.reverse_delay = param_find("VT_B_REV_DEL"); } void Standard::parameters_update() { float v; /* duration of a forwards transition to fw mode */ param_get(_params_handles_standard.pusher_ramp_dt, &v); _params_standard.pusher_ramp_dt = math::constrain(v, 0.0f, 20.0f); /* MC ramp up during back transition to mc mode */ param_get(_params_handles_standard.back_trans_ramp, &v); _params_standard.back_trans_ramp = math::constrain(v, 0.0f, _params->back_trans_duration); _airspeed_trans_blend_margin = _params->transition_airspeed - _params->airspeed_blend; /* maximum down pitch allowed */ param_get(_params_handles_standard.down_pitch_max, &v); _params_standard.down_pitch_max = math::radians(v); /* scale for fixed wing thrust used for forward acceleration in multirotor mode */ param_get(_params_handles_standard.forward_thrust_scale, &_params_standard.forward_thrust_scale); /* pitch setpoint offset */ param_get(_params_handles_standard.pitch_setpoint_offset, &v); _params_standard.pitch_setpoint_offset = math::radians(v); /* reverse output */ param_get(_params_handles_standard.reverse_output, &v); _params_standard.reverse_output = math::constrain(v, 0.0f, 1.0f); /* reverse output */ param_get(_params_handles_standard.reverse_delay, &v); _params_standard.reverse_delay = math::constrain(v, 0.0f, 10.0f); } void Standard::update_vtol_state() { /* After flipping the switch the vehicle will start the pusher (or tractor) motor, picking up * forward speed. After the vehicle has picked up enough speed the rotors shutdown. * For the back transition the pusher motor is immediately stopped and rotors reactivated. */ float mc_weight = _mc_roll_weight; float time_since_trans_start = (float)(hrt_absolute_time() - _vtol_schedule.transition_start) * 1e-6f; if (!_attc->is_fixed_wing_requested()) { // the transition to fw mode switch is off if (_vtol_schedule.flight_mode == MC_MODE) { // in mc mode _vtol_schedule.flight_mode = MC_MODE; mc_weight = 1.0f; _pusher_throttle = 0.0f; _reverse_output = 0.0f; } else if (_vtol_schedule.flight_mode == FW_MODE) { // transition to mc mode if (_vtol_vehicle_status->vtol_transition_failsafe == true) { // Failsafe event, engage mc motors immediately _vtol_schedule.flight_mode = MC_MODE; _pusher_throttle = 0.0f; _reverse_output = 0.0f; } else { // Regular backtransition _vtol_schedule.flight_mode = TRANSITION_TO_MC; _vtol_schedule.transition_start = hrt_absolute_time(); _reverse_output = _params_standard.reverse_output; } } else if (_vtol_schedule.flight_mode == TRANSITION_TO_FW) { // failsafe back to mc mode _vtol_schedule.flight_mode = MC_MODE; mc_weight = 1.0f; _pusher_throttle = 0.0f; _reverse_output = 0.0f; } else if (_vtol_schedule.flight_mode == TRANSITION_TO_MC) { // transition to MC mode if transition time has passed or forward velocity drops below MPC cruise speed const matrix::Dcmf R_to_body(matrix::Quatf(_v_att->q).inversed()); const matrix::Vector3f vel = R_to_body * matrix::Vector3f(_local_pos->vx, _local_pos->vy, _local_pos->vz); float x_vel = vel(0); if (time_since_trans_start > _params->back_trans_duration || (_local_pos->v_xy_valid && x_vel <= _params->mpc_xy_cruise)) { _vtol_schedule.flight_mode = MC_MODE; } } } else { // the transition to fw mode switch is on if (_vtol_schedule.flight_mode == MC_MODE || _vtol_schedule.flight_mode == TRANSITION_TO_MC) { // start transition to fw mode /* NOTE: The failsafe transition to fixed-wing was removed because it can result in an * unsafe flying state. */ _vtol_schedule.flight_mode = TRANSITION_TO_FW; _vtol_schedule.transition_start = hrt_absolute_time(); } else if (_vtol_schedule.flight_mode == FW_MODE) { // in fw mode _vtol_schedule.flight_mode = FW_MODE; mc_weight = 0.0f; } else if (_vtol_schedule.flight_mode == TRANSITION_TO_FW) { // continue the transition to fw mode while monitoring airspeed for a final switch to fw mode if (((_params->airspeed_disabled || _airspeed->indicated_airspeed_m_s >= _params->transition_airspeed) && time_since_trans_start > _params->front_trans_time_min) || can_transition_on_ground()) { _vtol_schedule.flight_mode = FW_MODE; // don't set pusher throttle here as it's being ramped up elsewhere _trans_finished_ts = hrt_absolute_time(); } } } _mc_roll_weight = mc_weight; _mc_pitch_weight = mc_weight; _mc_yaw_weight = mc_weight; _mc_throttle_weight = mc_weight; // map specific control phases to simple control modes switch (_vtol_schedule.flight_mode) { case MC_MODE: _vtol_mode = mode::ROTARY_WING; break; case FW_MODE: _vtol_mode = mode::FIXED_WING; break; case TRANSITION_TO_FW: _vtol_mode = mode::TRANSITION_TO_FW; break; case TRANSITION_TO_MC: _vtol_mode = mode::TRANSITION_TO_MC; break; } } void Standard::update_transition_state() { float mc_weight = 1.0f; float time_since_trans_start = (float)(hrt_absolute_time() - _vtol_schedule.transition_start) * 1e-6f; VtolType::update_transition_state(); // copy virtual attitude setpoint to real attitude setpoint memcpy(_v_att_sp, _mc_virtual_att_sp, sizeof(vehicle_attitude_setpoint_s)); if (_vtol_schedule.flight_mode == TRANSITION_TO_FW) { if (_params_standard.pusher_ramp_dt <= 0.0f) { // just set the final target throttle value _pusher_throttle = _params->front_trans_throttle; } else if (_pusher_throttle <= _params->front_trans_throttle) { // ramp up throttle to the target throttle value _pusher_throttle = _params->front_trans_throttle * time_since_trans_start / _params_standard.pusher_ramp_dt; } // do blending of mc and fw controls if a blending airspeed has been provided and the minimum transition time has passed if (_airspeed_trans_blend_margin > 0.0f && _airspeed->indicated_airspeed_m_s > 0.0f && _airspeed->indicated_airspeed_m_s >= _params->airspeed_blend && time_since_trans_start > _params->front_trans_time_min) { mc_weight = 1.0f - fabsf(_airspeed->indicated_airspeed_m_s - _params->airspeed_blend) / _airspeed_trans_blend_margin; // time based blending when no airspeed sensor is set } else if (_params->airspeed_disabled) { mc_weight = 1.0f - time_since_trans_start / _params->front_trans_time_min; mc_weight = math::constrain(2.0f * mc_weight, 0.0f, 1.0f); } // ramp up FW_PSP_OFF _v_att_sp->pitch_body = _params_standard.pitch_setpoint_offset * (1.0f - mc_weight); matrix::Quatf q_sp(matrix::Eulerf(_v_att_sp->roll_body, _v_att_sp->pitch_body, _v_att_sp->yaw_body)); q_sp.copyTo(_v_att_sp->q_d); _v_att_sp->q_d_valid = true; // check front transition timeout if (_params->front_trans_timeout > FLT_EPSILON) { if (time_since_trans_start > _params->front_trans_timeout) { // transition timeout occured, abort transition _attc->abort_front_transition("Transition timeout"); } } } else if (_vtol_schedule.flight_mode == TRANSITION_TO_MC) { // maintain FW_PSP_OFF _v_att_sp->pitch_body = _params_standard.pitch_setpoint_offset; matrix::Quatf q_sp(matrix::Eulerf(_v_att_sp->roll_body, _v_att_sp->pitch_body, _v_att_sp->yaw_body)); q_sp.copyTo(_v_att_sp->q_d); _v_att_sp->q_d_valid = true; _pusher_throttle = 0.0f; if (time_since_trans_start >= _params_standard.reverse_delay) { // Handle throttle reversal for active breaking float thrscale = (time_since_trans_start - _params_standard.reverse_delay) / (_params_standard.pusher_ramp_dt); thrscale = math::constrain(thrscale, 0.0f, 1.0f); _pusher_throttle = thrscale * _params->back_trans_throttle; } // continually increase mc attitude control as we transition back to mc mode if (_params_standard.back_trans_ramp > FLT_EPSILON) { mc_weight = time_since_trans_start / _params_standard.back_trans_ramp; } // in back transition we need to start the MC motors again if (_motor_state != ENABLED) { _motor_state = set_motor_state(_motor_state, ENABLED); } } mc_weight = math::constrain(mc_weight, 0.0f, 1.0f); _mc_roll_weight = mc_weight; _mc_pitch_weight = mc_weight; _mc_yaw_weight = mc_weight; _mc_throttle_weight = mc_weight; } void Standard::update_mc_state() { VtolType::update_mc_state(); // if the thrust scale param is zero or the drone is on manual mode, // then the pusher-for-pitch strategy is disabled and we can return if (_params_standard.forward_thrust_scale < FLT_EPSILON || !_v_control_mode->flag_control_position_enabled) { return; } // Do not engage pusher assist during a failsafe event // There could be a problem with the fixed wing drive if (_attc->get_vtol_vehicle_status()->vtol_transition_failsafe) { return; } // disable pusher assist during landing if (_attc->get_pos_sp_triplet()->current.valid && _attc->get_pos_sp_triplet()->current.type == position_setpoint_s::SETPOINT_TYPE_LAND) { return; } matrix::Dcmf R(matrix::Quatf(_v_att->q)); matrix::Dcmf R_sp(matrix::Quatf(_v_att_sp->q_d)); matrix::Eulerf euler(R); matrix::Eulerf euler_sp(R_sp); _pusher_throttle = 0.0f; // direction of desired body z axis represented in earth frame matrix::Vector3f body_z_sp(R_sp(0, 2), R_sp(1, 2), R_sp(2, 2)); // rotate desired body z axis into new frame which is rotated in z by the current // heading of the vehicle. we refer to this as the heading frame. matrix::Dcmf R_yaw = matrix::Eulerf(0.0f, 0.0f, -euler(2)); body_z_sp = R_yaw * body_z_sp; body_z_sp.normalize(); // calculate the desired pitch seen in the heading frame // this value corresponds to the amount the vehicle would try to pitch forward float pitch_forward = atan2f(body_z_sp(0), body_z_sp(2)); // only allow pitching forward up to threshold, the rest of the desired // forward acceleration will be compensated by the pusher if (pitch_forward < -_params_standard.down_pitch_max) { // desired roll angle in heading frame stays the same float roll_new = -asinf(body_z_sp(1)); _pusher_throttle = (sinf(-pitch_forward) - sinf(_params_standard.down_pitch_max)) * _params_standard.forward_thrust_scale; // return the vehicle to level position float pitch_new = 0.0f; // create corrected desired body z axis in heading frame matrix::Dcmf R_tmp = matrix::Eulerf(roll_new, pitch_new, 0.0f); matrix::Vector3f tilt_new(R_tmp(0, 2), R_tmp(1, 2), R_tmp(2, 2)); // rotate the vector into a new frame which is rotated in z by the desired heading // with respect to the earh frame. const float yaw_error = wrap_pi(euler_sp(2) - euler(2)); matrix::Dcmf R_yaw_correction = matrix::Eulerf(0.0f, 0.0f, -yaw_error); tilt_new = R_yaw_correction * tilt_new; // now extract roll and pitch setpoints _v_att_sp->pitch_body = atan2f(tilt_new(0), tilt_new(2)); _v_att_sp->roll_body = -asinf(tilt_new(1)); R_sp = matrix::Eulerf(_v_att_sp->roll_body, _v_att_sp->pitch_body, euler_sp(2)); matrix::Quatf q_sp(R_sp); q_sp.copyTo(_v_att_sp->q_d); } _pusher_throttle = _pusher_throttle < 0.0f ? 0.0f : _pusher_throttle; } void Standard::update_fw_state() { VtolType::update_fw_state(); } /** * Prepare message to acutators with data from mc and fw attitude controllers. An mc attitude weighting will determine * what proportion of control should be applied to each of the control groups (mc and fw). */ void Standard::fill_actuator_outputs() { // multirotor controls _actuators_out_0->timestamp = hrt_absolute_time(); _actuators_out_0->timestamp_sample = _actuators_mc_in->timestamp_sample; // roll _actuators_out_0->control[actuator_controls_s::INDEX_ROLL] = _actuators_mc_in->control[actuator_controls_s::INDEX_ROLL] * _mc_roll_weight; // pitch _actuators_out_0->control[actuator_controls_s::INDEX_PITCH] = _actuators_mc_in->control[actuator_controls_s::INDEX_PITCH] * _mc_pitch_weight; // yaw _actuators_out_0->control[actuator_controls_s::INDEX_YAW] = _actuators_mc_in->control[actuator_controls_s::INDEX_YAW] * _mc_yaw_weight; // throttle _actuators_out_0->control[actuator_controls_s::INDEX_THROTTLE] = _actuators_mc_in->control[actuator_controls_s::INDEX_THROTTLE] * _mc_throttle_weight; // fixed wing controls _actuators_out_1->timestamp = hrt_absolute_time(); _actuators_out_1->timestamp_sample = _actuators_fw_in->timestamp_sample; if (_vtol_schedule.flight_mode != MC_MODE) { // roll _actuators_out_1->control[actuator_controls_s::INDEX_ROLL] = -_actuators_fw_in->control[actuator_controls_s::INDEX_ROLL]; // pitch _actuators_out_1->control[actuator_controls_s::INDEX_PITCH] = _actuators_fw_in->control[actuator_controls_s::INDEX_PITCH]; // yaw _actuators_out_1->control[actuator_controls_s::INDEX_YAW] = _actuators_fw_in->control[actuator_controls_s::INDEX_YAW]; _actuators_out_1->control[actuator_controls_s::INDEX_AIRBRAKES] = _reverse_output; } else { if (_params->elevons_mc_lock) { // zero outputs when inactive _actuators_out_1->control[actuator_controls_s::INDEX_ROLL] = 0.0f; _actuators_out_1->control[actuator_controls_s::INDEX_PITCH] = 0.0f; _actuators_out_1->control[actuator_controls_s::INDEX_YAW] = 0.0f; _actuators_out_1->control[actuator_controls_s::INDEX_AIRBRAKES] = 0.0f; } else { // roll _actuators_out_1->control[actuator_controls_s::INDEX_ROLL] = -_actuators_fw_in->control[actuator_controls_s::INDEX_ROLL]; // pitch _actuators_out_1->control[actuator_controls_s::INDEX_PITCH] = _actuators_fw_in->control[actuator_controls_s::INDEX_PITCH]; _actuators_out_1->control[actuator_controls_s::INDEX_YAW] = 0.0f; _actuators_out_1->control[actuator_controls_s::INDEX_AIRBRAKES] = 0.0f; } } // set the fixed wing throttle control if (_vtol_schedule.flight_mode == FW_MODE) { // take the throttle value commanded by the fw controller _actuators_out_1->control[actuator_controls_s::INDEX_THROTTLE] = _actuators_fw_in->control[actuator_controls_s::INDEX_THROTTLE]; } else { // otherwise we may be ramping up the throttle during the transition to fw mode _actuators_out_1->control[actuator_controls_s::INDEX_THROTTLE] = _pusher_throttle; } } void Standard::waiting_on_tecs() { // keep thrust from transition _v_att_sp->thrust = _pusher_throttle; };