diff options
Diffstat (limited to 'apps/systemlib')
-rw-r--r-- | apps/systemlib/pid/pid.c | 148 | ||||
-rw-r--r-- | apps/systemlib/pid/pid.h | 74 |
2 files changed, 222 insertions, 0 deletions
diff --git a/apps/systemlib/pid/pid.c b/apps/systemlib/pid/pid.c new file mode 100644 index 000000000..a24657a41 --- /dev/null +++ b/apps/systemlib/pid/pid.c @@ -0,0 +1,148 @@ +/**************************************************************************** + * + * Copyright (C) 2008-2012 PX4 Development Team. All rights reserved. + * Author: @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 pid.c + * Implementation of generic PID control interface + */ + +#include "pid.h" + +void pid_init(PID_t *pid, float kp, float ki, float kd, float intmax, + uint8_t mode, uint8_t plot_i) +{ + pid->kp = kp; + pid->ki = ki; + pid->kd = kd; + pid->intmax = intmax; + pid->mode = mode; + pid->plot_i = plot_i; + pid->count = 0; + pid->saturated = 0; + + pid->sp = 0; + pid->error_previous = 0; + pid->integral = 0; +} +void pid_set_parameters(PID_t *pid, float kp, float ki, float kd, float intmax) +{ + pid->kp = kp; + pid->ki = ki; + pid->kd = kd; + pid->intmax = intmax; + // pid->mode = mode; + + // pid->sp = 0; + // pid->error_previous = 0; + // pid->integral = 0; +} + +//void pid_set(PID_t *pid, float sp) +//{ +// pid->sp = sp; +// pid->error_previous = 0; +// pid->integral = 0; +//} + +/** + * + * @param pid + * @param val + * @param dt + * @return + */ +float pid_calculate(PID_t *pid, float sp, float val, float val_dot, float dt) +{ + /* error = setpoint - actual_position + integral = integral + (error*dt) + derivative = (error - previous_error)/dt + output = (Kp*error) + (Ki*integral) + (Kd*derivative) + previous_error = error + wait(dt) + goto start + */ + + float i, d; + pid->sp = sp; + float error = pid->sp - val; + + if (pid->saturated && (pid->integral * error > 0)) { + //Output is saturated and the integral would get bigger (positive or negative) + i = pid->integral; + + //Reset saturation. If we are still saturated this will be set again at output limit check. + pid->saturated = 0; + + } else { + i = pid->integral + (error * dt); + } + + // Anti-Windup. Needed if we don't use the saturation above. + if (pid->intmax != 0.0) { + if (i > pid->intmax) { + pid->integral = pid->intmax; + + } else if (i < -pid->intmax) { + + pid->integral = -pid->intmax; + + } else { + pid->integral = i; + } + + //Send Controller integrals + // Disabled because of new possibilities with debug_vect. + // Now sent in Main Loop at 5 Hz. 26.06.2010 Laurens + // if (pid->plot_i && (pid->count++ % 16 == 0)&&(global_data.param[PARAM_SEND_SLOT_DEBUG_2] == 1)) + // { + // mavlink_msg_debug_send(MAVLINK_COMM_1, pid->plot_i, pid->integral); + // } + } + + if (pid->mode == PID_MODE_DERIVATIV_CALC) { + d = (error - pid->error_previous) / dt; + + } else if (pid->mode == PID_MODE_DERIVATIV_SET) { + d = -val_dot; + + } else { + d = 0; + } + + pid->error_previous = error; + + return (error * pid->kp) + (i * pid->ki) + (d * pid->kd); +} diff --git a/apps/systemlib/pid/pid.h b/apps/systemlib/pid/pid.h new file mode 100644 index 000000000..d62843ed4 --- /dev/null +++ b/apps/systemlib/pid/pid.h @@ -0,0 +1,74 @@ +/**************************************************************************** + * + * Copyright (C) 2008-2012 PX4 Development Team. All rights reserved. + * Author: @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 pid.h + * Definition of generic PID control interface + */ + +#ifndef PID_H_ +#define PID_H_ + +#include <stdint.h> + +/* PID_MODE_DERIVATIV_CALC calculates discrete derivative from previous error + * val_dot in pid_calculate() will be ignored */ +#define PID_MODE_DERIVATIV_CALC 0 +/* Use PID_MODE_DERIVATIV_SET if you have the derivative already (Gyros, Kalman) */ +#define PID_MODE_DERIVATIV_SET 1 + +typedef struct { + float kp; + float ki; + float kd; + float intmax; + float sp; + float integral; + float error_previous; + uint8_t mode; + uint8_t plot_i; + uint8_t count; + uint8_t saturated; +} PID_t; + +void pid_init(PID_t *pid, float kp, float ki, float kd, float intmax, uint8_t mode, uint8_t plot_i); +void pid_set_parameters(PID_t *pid, float kp, float ki, float kd, float intmax); +//void pid_set(PID_t *pid, float sp); +float pid_calculate(PID_t *pid, float sp, float val, float val_dot, float dt); + + + +#endif /* PID_H_ */ |