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Fixed pwm limit command to behave as originally designed. The initial hold time produced random values (e.g. 40000 instead of 1500) during the INIT_TIME (0.5s) phase

This commit is contained in:
Lorenz Meier 2014-01-02 09:18:04 +01:00
parent eb47a164cb
commit a60fcc2535
2 changed files with 55 additions and 37 deletions
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90
src/modules/systemlib/pwm_limit/pwm_limit.c
View File

@ -1,6 +1,6 @@
/****************************************************************************
*
* Copyright (C) 2013 PX4 Development Team. All rights reserved.
* Copyright (c) 2013, 2014 PX4 Development Team. All rights reserved.
* Author: Julian Oes <joes@student.ethz.ch>
*
* Redistribution and use in source and binary forms, with or without
@ -44,38 +44,53 @@
#include <math.h>
#include <stdbool.h>
#include <drivers/drv_hrt.h>
#include <stdio.h>
void pwm_limit_init(pwm_limit_t *limit)
{
limit->state = PWM_LIMIT_STATE_OFF;
limit->state = PWM_LIMIT_STATE_INIT;
limit->time_armed = 0;
return;
}
void pwm_limit_calc(const bool armed, const unsigned num_channels, const uint16_t *disarmed_pwm, const uint16_t *min_pwm, const uint16_t *max_pwm, float *output, uint16_t *effective_pwm, pwm_limit_t *limit)
void pwm_limit_calc(const bool armed, const unsigned num_channels, const uint16_t *disarmed_pwm, const uint16_t *min_pwm, const uint16_t *max_pwm, const float *output, uint16_t *effective_pwm, pwm_limit_t *limit)
{
/* first evaluate state changes */
switch (limit->state) {
case PWM_LIMIT_STATE_OFF:
if (armed)
limit->state = PWM_LIMIT_STATE_RAMP;
limit->time_armed = hrt_absolute_time();
break;
case PWM_LIMIT_STATE_INIT:
if (!armed)
limit->state = PWM_LIMIT_STATE_OFF;
else if (hrt_absolute_time() - limit->time_armed >= INIT_TIME_US)
if (armed) {
/* set arming time for the first call */
if (limit->time_armed == 0) {
limit->time_armed = hrt_absolute_time();
}
if (hrt_elapsed_time(&limit->time_armed) >= INIT_TIME_US) {
limit->state = PWM_LIMIT_STATE_OFF;
}
}
break;
case PWM_LIMIT_STATE_OFF:
if (armed) {
limit->state = PWM_LIMIT_STATE_RAMP;
/* reset arming time, used for ramp timing */
limit->time_armed = hrt_absolute_time();
}
break;
case PWM_LIMIT_STATE_RAMP:
if (!armed)
if (!armed) {
limit->state = PWM_LIMIT_STATE_OFF;
else if (hrt_absolute_time() - limit->time_armed >= INIT_TIME_US + RAMP_TIME_US)
} else if (hrt_elapsed_time(&limit->time_armed) >= RAMP_TIME_US) {
limit->state = PWM_LIMIT_STATE_ON;
}
break;
case PWM_LIMIT_STATE_ON:
if (!armed)
if (!armed) {
limit->state = PWM_LIMIT_STATE_OFF;
}
break;
default:
break;
@ -90,40 +105,43 @@ void pwm_limit_calc(const bool armed, const unsigned num_channels, const uint16_
case PWM_LIMIT_STATE_INIT:
for (unsigned i=0; i<num_channels; i++) {
effective_pwm[i] = disarmed_pwm[i];
output[i] = 0.0f;
}
break;
case PWM_LIMIT_STATE_RAMP:
{
hrt_abstime diff = hrt_elapsed_time(&limit->time_armed);
progress = (hrt_absolute_time() - INIT_TIME_US - limit->time_armed)*10000 / RAMP_TIME_US;
for (unsigned i=0; i<num_channels; i++) {
uint16_t ramp_min_pwm;
/* if a disarmed pwm value was set, blend between disarmed and min */
if (disarmed_pwm[i] > 0) {
progress = diff * 10000 / RAMP_TIME_US;
/* safeguard against overflows */
uint16_t disarmed = disarmed_pwm[i];
if (disarmed > min_pwm[i])
disarmed = min_pwm[i];
for (unsigned i=0; i<num_channels; i++) {
uint16_t ramp_min_pwm;
/* if a disarmed pwm value was set, blend between disarmed and min */
if (disarmed_pwm[i] > 0) {
uint16_t disarmed_min_diff = min_pwm[i] - disarmed;
ramp_min_pwm = disarmed + (disarmed_min_diff * progress) / 10000;
} else {
/* no disarmed pwm value set, choose min pwm */
ramp_min_pwm = min_pwm[i];
/* safeguard against overflows */
unsigned disarmed = disarmed_pwm[i];
if (disarmed > min_pwm[i]) {
disarmed = min_pwm[i];
}
unsigned disarmed_min_diff = min_pwm[i] - disarmed;
ramp_min_pwm = disarmed + (disarmed_min_diff * progress) / 10000;
} else {
/* no disarmed pwm value set, choose min pwm */
ramp_min_pwm = min_pwm[i];
}
effective_pwm[i] = output[i] * (max_pwm[i] - ramp_min_pwm)/2 + (max_pwm[i] + ramp_min_pwm)/2;
}
effective_pwm[i] = output[i] * (max_pwm[i] - ramp_min_pwm)/2 + (max_pwm[i] + ramp_min_pwm)/2;
output[i] = (float)progress/10000.0f * output[i];
}
break;
case PWM_LIMIT_STATE_ON:
for (unsigned i=0; i<num_channels; i++) {
effective_pwm[i] = output[i] * (max_pwm[i] - min_pwm[i])/2 + (max_pwm[i] + min_pwm[i])/2;
/* effective_output stays the same */
}
break;
default:

2
src/modules/systemlib/pwm_limit/pwm_limit.h
View File

@ -72,7 +72,7 @@ typedef struct {
__EXPORT void pwm_limit_init(pwm_limit_t *limit);
__EXPORT void pwm_limit_calc(const bool armed, const unsigned num_channels, const uint16_t *disarmed_pwm, const uint16_t *min_pwm, const uint16_t *max_pwm, float *output, uint16_t *effective_pwm, pwm_limit_t *limit);
__EXPORT void pwm_limit_calc(const bool armed, const unsigned num_channels, const uint16_t *disarmed_pwm, const uint16_t *min_pwm, const uint16_t *max_pwm, const float *output, uint16_t *effective_pwm, pwm_limit_t *limit);
__END_DECLS