double promotion warning fix or ignore per module

src/lib/pid/pid.cpp

@@ -0,0 +1,185 @@
+/****************************************************************************
+ *
+ *   Copyright (C) 2008-2013 PX4 Development Team. All rights reserved.
+ *   Author: Laurens Mackay <mackayl@student.ethz.ch>
+ *           Tobias Naegeli <naegelit@student.ethz.ch>
+ *           Martin Rutschmann <rutmarti@student.ethz.ch>
+ *           Anton Babushkin <anton.babushkin@me.com>
+ *           Julian Oes <joes@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 controller.
+ *
+ * @author Laurens Mackay <mackayl@student.ethz.ch>
+ * @author Tobias Naegeli <naegelit@student.ethz.ch>
+ * @author Martin Rutschmann <rutmarti@student.ethz.ch>
+ * @author Anton Babushkin <anton.babushkin@me.com>
+ * @author Julian Oes <joes@student.ethz.ch>
+ */
+
+#include "pid.h"
+#include <math.h>
+#include <px4_defines.h>
+
+#define SIGMA 0.000001f
+
+__EXPORT void pid_init(PID_t *pid, pid_mode_t mode, float dt_min)
+{
+	pid->mode = mode;
+	pid->dt_min = dt_min;
+	pid->kp = 0.0f;
+	pid->ki = 0.0f;
+	pid->kd = 0.0f;
+	pid->integral = 0.0f;
+	pid->integral_limit = 0.0f;
+	pid->output_limit = 0.0f;
+	pid->error_previous = 0.0f;
+	pid->last_output = 0.0f;
+}
+
+__EXPORT int pid_set_parameters(PID_t *pid, float kp, float ki, float kd, float integral_limit, float output_limit)
+{
+	int ret = 0;
+
+	if (PX4_ISFINITE(kp)) {
+		pid->kp = kp;
+
+	} else {
+		ret = 1;
+	}
+
+	if (PX4_ISFINITE(ki)) {
+		pid->ki = ki;
+
+	} else {
+		ret = 1;
+	}
+
+	if (PX4_ISFINITE(kd)) {
+		pid->kd = kd;
+
+	} else {
+		ret = 1;
+	}
+
+	if (PX4_ISFINITE(integral_limit)) {
+		pid->integral_limit = integral_limit;
+
+	}  else {
+		ret = 1;
+	}
+
+	if (PX4_ISFINITE(output_limit)) {
+		pid->output_limit = output_limit;
+
+	}  else {
+		ret = 1;
+	}
+
+	return ret;
+}
+
+__EXPORT float pid_calculate(PID_t *pid, float sp, float val, float val_dot, float dt)
+{
+	if (!PX4_ISFINITE(sp) || !PX4_ISFINITE(val) || !PX4_ISFINITE(val_dot) || !PX4_ISFINITE(dt)) {
+		return pid->last_output;
+	}
+
+	float i, d;
+
+	/* current error value */
+	float error = sp - val;
+
+	/* current error derivative */
+	if (pid->mode == PID_MODE_DERIVATIV_CALC) {
+		d = (error - pid->error_previous) / fmaxf(dt, pid->dt_min);
+		pid->error_previous = error;
+
+	} else if (pid->mode == PID_MODE_DERIVATIV_CALC_NO_SP) {
+		d = (-val - pid->error_previous) / fmaxf(dt, pid->dt_min);
+		pid->error_previous = -val;
+
+	} else if (pid->mode == PID_MODE_DERIVATIV_SET) {
+		d = -val_dot;
+
+	} else {
+		d = 0.0f;
+	}
+
+	if (!PX4_ISFINITE(d)) {
+		d = 0.0f;
+	}
+
+	/* calculate PD output */
+	float output = (error * pid->kp) + (d * pid->kd);
+
+	if (pid->ki > SIGMA) {
+		// Calculate the error integral and check for saturation
+		i = pid->integral + (error * dt);
+
+		/* check for saturation */
+		if (PX4_ISFINITE(i)) {
+			if ((pid->output_limit < SIGMA || (fabsf(output + (i * pid->ki)) <= pid->output_limit)) &&
+			    fabsf(i) <= pid->integral_limit) {
+				/* not saturated, use new integral value */
+				pid->integral = i;
+			}
+		}
+
+		/* add I component to output */
+		output += pid->integral * pid->ki;
+	}
+
+	/* limit output */
+	if (PX4_ISFINITE(output)) {
+		if (pid->output_limit > SIGMA) {
+			if (output > pid->output_limit) {
+				output = pid->output_limit;
+
+			} else if (output < -pid->output_limit) {
+				output = -pid->output_limit;
+			}
+		}
+
+		pid->last_output = output;
+	}
+
+	return pid->last_output;
+}
+
+
+__EXPORT void pid_reset_integral(PID_t *pid)
+{
+	pid->integral = 0.0f;
+}