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Diffstat (limited to 'apps/multirotor_pos_control/position_control.c')
| -rw-r--r-- | apps/multirotor_pos_control/position_control.c | 275 |
1 files changed, 275 insertions, 0 deletions
diff --git a/apps/multirotor_pos_control/position_control.c b/apps/multirotor_pos_control/position_control.c new file mode 100644 index 000000000..fd731a33d --- /dev/null +++ b/apps/multirotor_pos_control/position_control.c @@ -0,0 +1,275 @@ +/**************************************************************************** + * + * Copyright (C) 2008-2012 PX4 Development Team. All rights reserved. + * Author: @author Lorenz Meier <lm@inf.ethz.ch> + * @author Laurens Mackay <mackayl@student.ethz.ch> + * @author Tobias Naegeli <naegelit@student.ethz.ch> + * @author Martin Rutschmann <rutmarti@student.ethz.ch> + * + * 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 multirotor_position_control.c + * Implementation of the position control for a multirotor VTOL + */ + +#include <stdio.h> +#include <stdlib.h> +#include <stdio.h> +#include <stdint.h> +#include <math.h> +#include <stdbool.h> +#include <float.h> +#include <systemlib/pid/pid.h> + +#include "multirotor_position_control.h" + +float get_distance_to_next_waypoint(double lat_now, double lon_now, double lat_next, double lon_next) +{ + double lat_now_rad = lat_now / 180.0 * M_PI; + double lon_now_rad = lon_now / 180.0 * M_PI; + double lat_next_rad = lat_next / 180.0 * M_PI; + double lon_next_rad = lon_next / 180.0 * M_PI; + + + double d_lat = lat_next_rad - lat_now_rad; + double d_lon = lon_next_rad - lon_now_rad; + + double a = sin(d_lat / 2.0) * sin(d_lat / 2.0) + sin(d_lon / 2.0) * sin(d_lon / 2.0) * cos(lat_now_rad) * cos(lat_next_rad); + double c = 2 * atan2(sqrt(a), sqrt(1 - a)); + + const double radius_earth = 6371000.0; + + return radius_earth * c; +} + +float get_bearing_to_next_waypoint(double lat_now, double lon_now, double lat_next, double lon_next) +{ + double lat_now_rad = lat_now / 180.0 * M_PI; + double lon_now_rad = lon_now / 180.0 * M_PI; + double lat_next_rad = lat_next / 180.0 * M_PI; + double lon_next_rad = lon_next / 180.0 * M_PI; + + double d_lat = lat_next_rad - lat_now_rad; + double d_lon = lon_next_rad - lon_now_rad; + + /* conscious mix of double and float trig function to maximize speed and efficiency */ + float theta = atan2f(sin(d_lon) * cos(lat_next_rad) , cos(lat_now_rad) * sin(lat_next_rad) - sin(lat_now_rad) * cos(lat_next_rad) * cos(d_lon)); + + // XXX wrapping check is incomplete + if (theta < 0.0f) { + theta = theta + 2.0f * M_PI_F; + } + + return theta; +} + +void control_multirotor_position(const struct vehicle_state_s *vstatus, const struct vehicle_manual_control_s *manual, + const struct vehicle_attitude_s *att, const struct vehicle_local_position_s *local_pos, + const struct vehicle_local_position_setpoint_s *local_pos_sp, struct vehicle_attitude_setpoint_s *att_sp) +{ + static PID_t distance_controller; + + static int read_ret; + static global_data_position_t position_estimated; + + static uint16_t counter; + + static bool initialized; + static uint16_t pm_counter; + + static float lat_next; + static float lon_next; + + static float pitch_current; + + static float thrust_total; + + + if (initialized == false) { + + pid_init(&distance_controller, + global_data_parameter_storage->pm.param_values[PARAM_PID_POS_P], + global_data_parameter_storage->pm.param_values[PARAM_PID_POS_I], + global_data_parameter_storage->pm.param_values[PARAM_PID_POS_D], + global_data_parameter_storage->pm.param_values[PARAM_PID_POS_AWU], + PID_MODE_DERIVATIV_CALC, 150);//150 + +// pid_pos_lim = global_data_parameter_storage->pm.param_values[PARAM_PID_POS_LIM]; +// pid_pos_z_lim = global_data_parameter_storage->pm.param_values[PARAM_PID_POS_Z_LIM]; + + thrust_total = 0.0f; + + /* Position initialization */ + /* Wait for new position estimate */ + do { + read_ret = read_lock_position(&position_estimated); + } while (read_ret != 0); + + lat_next = position_estimated.lat; + lon_next = position_estimated.lon; + + /* attitude initialization */ + global_data_lock(&global_data_attitude->access_conf); + pitch_current = global_data_attitude->pitch; + global_data_unlock(&global_data_attitude->access_conf); + + initialized = true; + } + + /* load new parameters with 10Hz */ + if (counter % 50 == 0) { + if (global_data_trylock(&global_data_parameter_storage->access_conf) == 0) { + /* check whether new parameters are available */ + if (global_data_parameter_storage->counter > pm_counter) { + pid_set_parameters(&distance_controller, + global_data_parameter_storage->pm.param_values[PARAM_PID_POS_P], + global_data_parameter_storage->pm.param_values[PARAM_PID_POS_I], + global_data_parameter_storage->pm.param_values[PARAM_PID_POS_D], + global_data_parameter_storage->pm.param_values[PARAM_PID_POS_AWU]); + +// +// pid_pos_lim = global_data_parameter_storage->pm.param_values[PARAM_PID_POS_LIM]; +// pid_pos_z_lim = global_data_parameter_storage->pm.param_values[PARAM_PID_POS_Z_LIM]; + + pm_counter = global_data_parameter_storage->counter; + printf("Position controller changed pid parameters\n"); + } + } + + global_data_unlock(&global_data_parameter_storage->access_conf); + } + + + /* Wait for new position estimate */ + do { + read_ret = read_lock_position(&position_estimated); + } while (read_ret != 0); + + /* Get next waypoint */ //TODO: add local copy + + if (0 == global_data_trylock(&global_data_position_setpoint->access_conf)) { + lat_next = global_data_position_setpoint->x; + lon_next = global_data_position_setpoint->y; + global_data_unlock(&global_data_position_setpoint->access_conf); + } + + /* Get distance to waypoint */ + float distance_to_waypoint = get_distance_to_next_waypoint(position_estimated.lat , position_estimated.lon, lat_next, lon_next); +// if(counter % 5 == 0) +// printf("distance_to_waypoint: %.4f\n", distance_to_waypoint); + + /* Get bearing to waypoint (direction on earth surface to next waypoint) */ + float bearing = get_bearing_to_next_waypoint(position_estimated.lat, position_estimated.lon, lat_next, lon_next); + + if (counter % 5 == 0) + printf("bearing: %.4f\n", bearing); + + /* Calculate speed in direction of bearing (needed for controller) */ + float speed_norm = sqrtf(position_estimated.vx * position_estimated.vx + position_estimated.vy * position_estimated.vy); +// if(counter % 5 == 0) +// printf("speed_norm: %.4f\n", speed_norm); + float speed_to_waypoint = 0; //(position_estimated.vx * cosf(bearing) + position_estimated.vy * sinf(bearing))/speed_norm; //FIXME, TODO: re-enable this once we have a full estimate of the speed, then we can do a PID for the distance controller + + /* Control Thrust in bearing direction */ + float horizontal_thrust = -pid_calculate(&distance_controller, 0, distance_to_waypoint, speed_to_waypoint, + CONTROL_PID_POSITION_INTERVAL); //TODO: maybe this "-" sign is an error somewhere else + +// if(counter % 5 == 0) +// printf("horizontal thrust: %.4f\n", horizontal_thrust); + + /* Get total thrust (from remote for now) */ + if (0 == global_data_trylock(&global_data_rc_channels->access_conf)) { + thrust_total = (float)global_data_rc_channels->chan[THROTTLE].scale; //TODO: how should we use the RC_CHANNELS_FUNCTION enum? + global_data_unlock(&global_data_rc_channels->access_conf); + } + + const float max_gas = 500.0f; + thrust_total *= max_gas / 20000.0f; //TODO: check this + thrust_total += max_gas / 2.0f; + + + if (horizontal_thrust > thrust_total) { + horizontal_thrust = thrust_total; + + } else if (horizontal_thrust < -thrust_total) { + horizontal_thrust = -thrust_total; + } + + + + //TODO: maybe we want to add a speed controller later... + + /* Calclulate thrust in east and north direction */ + float thrust_north = cosf(bearing) * horizontal_thrust; + float thrust_east = sinf(bearing) * horizontal_thrust; + + if (counter % 10 == 0) { + printf("thrust north: %.4f\n", thrust_north); + printf("thrust east: %.4f\n", thrust_east); + fflush(stdout); + } + + /* Get current attitude */ + if (0 == global_data_trylock(&global_data_attitude->access_conf)) { + pitch_current = global_data_attitude->pitch; + global_data_unlock(&global_data_attitude->access_conf); + } + + /* Get desired pitch & roll */ + float pitch_desired = 0.0f; + float roll_desired = 0.0f; + + if (thrust_total != 0) { + float pitch_fraction = -thrust_north / thrust_total; + float roll_fraction = thrust_east / (cosf(pitch_current) * thrust_total); + + if (roll_fraction < -1) { + roll_fraction = -1; + + } else if (roll_fraction > 1) { + roll_fraction = 1; + } + +// if(counter % 5 == 0) +// { +// printf("pitch_fraction: %.4f, roll_fraction: %.4f\n",pitch_fraction, roll_fraction); +// fflush(stdout); +// } + + pitch_desired = asinf(pitch_fraction); + roll_desired = asinf(roll_fraction); + } + + att_sp.roll = roll_desired; + att_sp.pitch = pitch_desired; + + counter++; +} |