/**************************************************************************** * * Copyright (c) 2013-2016 Estimation and Control Library (ECL). 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 ECL 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 ecl_yaw_controller.cpp * Implementation of a simple orthogonal coordinated turn yaw PID controller. * * Authors and acknowledgements in header. */ #include "ecl_yaw_controller.h" #include #include #include #include #include #include #include ECL_YawController::ECL_YawController() : ECL_Controller("yaw"), _coordinated_min_speed(1.0f), _coordinated_method(0) { } ECL_YawController::~ECL_YawController() { } float ECL_YawController::control_attitude(const struct ECL_ControlData &ctl_data) { switch (_coordinated_method) { case COORD_METHOD_OPEN: return control_attitude_impl_openloop(ctl_data); case COORD_METHOD_CLOSEACC: return control_attitude_impl_accclosedloop(ctl_data); default: static hrt_abstime last_print = 0; if (ecl_elapsed_time(&last_print) > 5e6) { warnx("invalid param setting FW_YCO_METHOD"); last_print = ecl_absolute_time(); } } return _rate_setpoint; } float ECL_YawController::control_bodyrate(const struct ECL_ControlData &ctl_data) { switch (_coordinated_method) { case COORD_METHOD_OPEN: case COORD_METHOD_CLOSEACC: return control_bodyrate_impl(ctl_data); default: static hrt_abstime last_print = 0; if (ecl_elapsed_time(&last_print) > 5e6) { warnx("invalid param setting FW_YCO_METHOD"); last_print = ecl_absolute_time(); } } return math::constrain(_last_output, -1.0f, 1.0f); } float ECL_YawController::control_attitude_impl_openloop(const struct ECL_ControlData &ctl_data) { /* Do not calculate control signal with bad inputs */ if (!(PX4_ISFINITE(ctl_data.roll) && PX4_ISFINITE(ctl_data.pitch) && PX4_ISFINITE(ctl_data.speed_body_u) && PX4_ISFINITE(ctl_data.speed_body_v) && PX4_ISFINITE(ctl_data.speed_body_w) && PX4_ISFINITE(ctl_data.roll_rate_setpoint) && PX4_ISFINITE(ctl_data.pitch_rate_setpoint))) { return _rate_setpoint; } // static int counter = 0; /* Calculate desired yaw rate from coordinated turn constraint / (no side forces) */ _rate_setpoint = 0.0f; if (sqrtf(ctl_data.speed_body_u * ctl_data.speed_body_u + ctl_data.speed_body_v * ctl_data.speed_body_v + ctl_data.speed_body_w * ctl_data.speed_body_w) > _coordinated_min_speed) { float denumerator = (ctl_data.speed_body_u * cosf(ctl_data.roll) * cosf(ctl_data.pitch) + ctl_data.speed_body_w * sinf(ctl_data.pitch)); if (fabsf(denumerator) > FLT_EPSILON) { _rate_setpoint = (ctl_data.speed_body_w * ctl_data.roll_rate_setpoint + 9.81f * sinf(ctl_data.roll) * cosf(ctl_data.pitch) + ctl_data.speed_body_u * ctl_data.pitch_rate_setpoint * sinf(ctl_data.roll)) / denumerator; // warnx("yaw: speed_body_u %.f speed_body_w %1.f roll %.1f pitch %.1f denumerator %.1f _rate_setpoint %.1f", speed_body_u, speed_body_w, denumerator, _rate_setpoint); } // if(counter % 20 == 0) { // warnx("denumerator: %.4f, speed_body_u: %.4f, speed_body_w: %.4f, cosf(roll): %.4f, cosf(pitch): %.4f, sinf(pitch): %.4f", (double)denumerator, (double)speed_body_u, (double)speed_body_w, (double)cosf(roll), (double)cosf(pitch), (double)sinf(pitch)); // } } /* limit the rate */ //XXX: move to body angluar rates if (_max_rate > 0.01f) { _rate_setpoint = (_rate_setpoint > _max_rate) ? _max_rate : _rate_setpoint; _rate_setpoint = (_rate_setpoint < -_max_rate) ? -_max_rate : _rate_setpoint; } // counter++; if (!PX4_ISFINITE(_rate_setpoint)) { warnx("yaw rate sepoint not finite"); _rate_setpoint = 0.0f; } return _rate_setpoint; } float ECL_YawController::control_bodyrate_impl(const struct ECL_ControlData &ctl_data) { /* Do not calculate control signal with bad inputs */ if (!(PX4_ISFINITE(ctl_data.roll) && PX4_ISFINITE(ctl_data.pitch) && PX4_ISFINITE(ctl_data.pitch_rate) && PX4_ISFINITE(ctl_data.yaw_rate) && PX4_ISFINITE(ctl_data.pitch_rate_setpoint) && PX4_ISFINITE(ctl_data.airspeed_min) && PX4_ISFINITE(ctl_data.airspeed_max) && PX4_ISFINITE(ctl_data.scaler))) { return math::constrain(_last_output, -1.0f, 1.0f); } /* get the usual dt estimate */ uint64_t dt_micros = ecl_elapsed_time(&_last_run); _last_run = ecl_absolute_time(); float dt = (float)dt_micros * 1e-6f; /* lock integral for long intervals */ bool lock_integrator = ctl_data.lock_integrator; if (dt_micros > 500000) { lock_integrator = true; } /* input conditioning */ float airspeed = ctl_data.airspeed; if (!PX4_ISFINITE(airspeed)) { /* airspeed is NaN, +- INF or not available, pick center of band */ airspeed = 0.5f * (ctl_data.airspeed_min + ctl_data.airspeed_max); } else if (airspeed < ctl_data.airspeed_min) { airspeed = ctl_data.airspeed_min; } /* Transform setpoint to body angular rates (jacobian) */ _bodyrate_setpoint = -sinf(ctl_data.roll) * ctl_data.pitch_rate_setpoint + cosf(ctl_data.roll) * cosf(ctl_data.pitch) * _rate_setpoint; /* Close the acceleration loop if _coordinated_method wants this: change body_rate setpoint */ if (_coordinated_method == COORD_METHOD_CLOSEACC) { //XXX: filtering of acceleration? _bodyrate_setpoint -= (ctl_data.acc_body_y / (airspeed * cosf(ctl_data.pitch))); } /* Calculate body angular rate error */ _rate_error = _bodyrate_setpoint - ctl_data.yaw_rate; //body angular rate error if (!lock_integrator && _k_i > 0.0f && airspeed > 0.5f * ctl_data.airspeed_min) { float id = _rate_error * dt; /* * anti-windup: do not allow integrator to increase if actuator is at limit */ if (_last_output < -1.0f) { /* only allow motion to center: increase value */ id = math::max(id, 0.0f); } else if (_last_output > 1.0f) { /* only allow motion to center: decrease value */ id = math::min(id, 0.0f); } _integrator += id * _k_i; } /* integrator limit */ //xxx: until start detection is available: integral part in control signal is limited here float integrator_constrained = math::constrain(_integrator, -_integrator_max, _integrator_max); /* Apply PI rate controller and store non-limited output */ _last_output = (_bodyrate_setpoint * _k_ff + _rate_error * _k_p + integrator_constrained) * ctl_data.scaler * ctl_data.scaler; //scaler is proportional to 1/airspeed //warnx("yaw:_last_output: %.4f, _integrator: %.4f, _integrator_max: %.4f, airspeed %.4f, _k_i %.4f, _k_p: %.4f", (double)_last_output, (double)_integrator, (double)_integrator_max, (double)airspeed, (double)_k_i, (double)_k_p); return math::constrain(_last_output, -1.0f, 1.0f); } float ECL_YawController::control_attitude_impl_accclosedloop(const struct ECL_ControlData &ctl_data) { /* dont set a rate setpoint */ return 0.0f; }