1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
|
/****************************************************************************
*
* Copyright (c) 2013 PX4 Development Team. All rights reserved.
* Author: Tobias Naegeli <naegelit@student.ethz.ch>
* Lorenz Meier <lm@inf.ethz.ch>
* Anton Babushkin <anton.babushkin@me.com>
*
* 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 mc_att_control_vector_main.c
* Implementation of a multicopter attitude controller based on desired rotation matrix.
*
* References
* [1] Daniel Mellinger and Vijay Kumar, "Minimum Snap Trajectory Generation and Control for Quadrotors",
* http://www.seas.upenn.edu/~dmel/mellingerICRA11.pdf
*
* @author Tobias Naegeli <naegelit@student.ethz.ch>
* @author Lorenz Meier <lm@inf.ethz.ch>
* @author Anton Babushkin <anton.babushkin@me.com>
*
*/
#include <nuttx/config.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <errno.h>
#include <math.h>
#include <poll.h>
#include <time.h>
#include <drivers/drv_hrt.h>
#include <arch/board/board.h>
#include <uORB/uORB.h>
#include <uORB/topics/vehicle_attitude_setpoint.h>
#include <uORB/topics/manual_control_setpoint.h>
#include <uORB/topics/actuator_controls.h>
#include <uORB/topics/vehicle_rates_setpoint.h>
#include <uORB/topics/vehicle_attitude.h>
#include <uORB/topics/vehicle_control_mode.h>
#include <uORB/topics/actuator_armed.h>
#include <uORB/topics/parameter_update.h>
#include <systemlib/param/param.h>
#include <systemlib/err.h>
#include <systemlib/pid/pid.h>
#include <systemlib/perf_counter.h>
#include <systemlib/systemlib.h>
#include <mathlib/mathlib.h>
#include <lib/geo/geo.h>
/**
* Multicopter attitude control app start / stop handling function
*
* @ingroup apps
*/
extern "C" __EXPORT int mc_att_control_vector_main(int argc, char *argv[]);
#define MIN_TAKEOFF_THROTTLE 0.3f
#define YAW_DEADZONE 0.01f
class MulticopterAttitudeControl
{
public:
/**
* Constructor
*/
MulticopterAttitudeControl();
/**
* Destructor, also kills the sensors task.
*/
~MulticopterAttitudeControl();
/**
* Start the sensors task.
*
* @return OK on success.
*/
int start();
private:
bool _task_should_exit; /**< if true, sensor task should exit */
int _control_task; /**< task handle for sensor task */
int _att_sub; /**< vehicle attitude subscription */
int _att_sp_sub; /**< vehicle attitude setpoint */
int _attitude_sub; /**< raw rc channels data subscription */
int _control_mode_sub; /**< vehicle control mode subscription */
int _params_sub; /**< notification of parameter updates */
int _manual_sub; /**< notification of manual control updates */
int _arming_sub; /**< arming status of outputs */
orb_advert_t _att_sp_pub; /**< attitude setpoint publication */
orb_advert_t _rates_sp_pub; /**< rate setpoint publication */
orb_advert_t _actuators_0_pub; /**< actuator control group 0 setpoint */
struct vehicle_attitude_s _att; /**< vehicle attitude */
struct vehicle_attitude_setpoint_s _att_sp; /**< vehicle attitude setpoint */
struct manual_control_setpoint_s _manual; /**< r/c channel data */
struct vehicle_control_mode_s _control_mode; /**< vehicle control mode */
struct actuator_controls_s _actuators; /**< actuator control inputs */
struct actuator_armed_s _arming; /**< actuator arming status */
struct vehicle_rates_setpoint_s _rates_sp; /**< vehicle rates setpoint */
perf_counter_t _loop_perf; /**< loop performance counter */
bool _setpoint_valid; /**< flag if the position control setpoint is valid */
math::Matrix _K; /**< diagonal gain matrix for position error */
math::Matrix _K_rate; /**< diagonal gain matrix for angular rate error */
struct {
param_t att_p;
param_t att_rate_p;
param_t yaw_p;
param_t yaw_rate_p;
} _parameter_handles; /**< handles for interesting parameters */
/**
* Update our local parameter cache.
*/
int parameters_update();
/**
* Update control outputs
*
*/
void control_update();
/**
* Check for changes in vehicle control mode.
*/
void vehicle_control_mode_poll();
/**
* Check for changes in manual inputs.
*/
void vehicle_manual_poll();
/**
* Check for set triplet updates.
*/
void vehicle_setpoint_poll();
/**
* Check for arming status updates.
*/
void arming_status_poll();
/**
* Shim for calling task_main from task_create.
*/
static void task_main_trampoline(int argc, char *argv[]);
/**
* Main sensor collection task.
*/
void task_main() __attribute__((noreturn));
};
namespace att_control
{
/* oddly, ERROR is not defined for c++ */
#ifdef ERROR
# undef ERROR
#endif
static const int ERROR = -1;
MulticopterAttitudeControl *g_control;
}
MulticopterAttitudeControl::MulticopterAttitudeControl() :
_task_should_exit(false),
_control_task(-1),
/* subscriptions */
_att_sub(-1),
_control_mode_sub(-1),
_params_sub(-1),
_manual_sub(-1),
_arming_sub(-1),
/* publications */
_rates_sp_pub(-1),
_actuators_0_pub(-1),
/* performance counters */
_loop_perf(perf_alloc(PC_ELAPSED, "fw att control")),
/* states */
_setpoint_valid(false),
/* gain matrices */
_K(3, 3),
_K_rate(3, 3)
{
_parameter_handles.att_p = param_find("MC_ATT_P");
_parameter_handles.att_rate_p = param_find("MC_ATTRATE_P");
_parameter_handles.yaw_p = param_find("MC_YAWPOS_P");
_parameter_handles.yaw_rate_p = param_find("MC_YAWRATE_P");
/* fetch initial parameter values */
parameters_update();
}
MulticopterAttitudeControl::~MulticopterAttitudeControl()
{
if (_control_task != -1) {
/* task wakes up every 100ms or so at the longest */
_task_should_exit = true;
/* wait for a second for the task to quit at our request */
unsigned i = 0;
do {
/* wait 20ms */
usleep(20000);
/* if we have given up, kill it */
if (++i > 50) {
task_delete(_control_task);
break;
}
} while (_control_task != -1);
}
att_control::g_control = nullptr;
}
int
MulticopterAttitudeControl::parameters_update()
{
float att_p;
float att_rate_p;
float yaw_p;
float yaw_rate_p;
param_get(_parameter_handles.att_p, &att_p);
param_get(_parameter_handles.att_rate_p, &att_rate_p);
param_get(_parameter_handles.yaw_p, &yaw_p);
param_get(_parameter_handles.yaw_rate_p, &yaw_rate_p);
_K(0, 0) = att_p;
_K(1, 1) = att_p;
_K(2, 2) = yaw_p;
_K_rate(0, 0) = att_rate_p;
_K_rate(1, 1) = att_rate_p;
_K_rate(2, 2) = yaw_rate_p;
return OK;
}
void
MulticopterAttitudeControl::vehicle_control_mode_poll()
{
bool control_mode_updated;
/* Check HIL state if vehicle status has changed */
orb_check(_control_mode_sub, &control_mode_updated);
if (control_mode_updated) {
orb_copy(ORB_ID(vehicle_control_mode), _control_mode_sub, &_control_mode);
}
}
void
MulticopterAttitudeControl::vehicle_manual_poll()
{
bool manual_updated;
/* get pilots inputs */
orb_check(_manual_sub, &manual_updated);
if (manual_updated) {
orb_copy(ORB_ID(manual_control_setpoint), _manual_sub, &_manual);
}
}
void
MulticopterAttitudeControl::vehicle_setpoint_poll()
{
/* check if there is a new setpoint */
bool att_sp_updated;
orb_check(_att_sp_sub, &att_sp_updated);
if (att_sp_updated) {
orb_copy(ORB_ID(vehicle_attitude_setpoint), _att_sp_sub, &_att_sp);
_setpoint_valid = true;
}
}
void
MulticopterAttitudeControl::arming_status_poll()
{
/* check if there is a new setpoint */
bool arming_updated;
orb_check(_arming_sub, &arming_updated);
if (arming_updated) {
orb_copy(ORB_ID(actuator_armed), _arming_sub, &_arming);
}
}
void
MulticopterAttitudeControl::task_main_trampoline(int argc, char *argv[])
{
att_control::g_control->task_main();
}
void
MulticopterAttitudeControl::task_main()
{
/* inform about start */
warnx("Initializing..");
fflush(stdout);
/*
* do subscriptions
*/
_att_sp_sub = orb_subscribe(ORB_ID(vehicle_attitude_setpoint));
_att_sub = orb_subscribe(ORB_ID(vehicle_attitude));
_control_mode_sub = orb_subscribe(ORB_ID(vehicle_control_mode));
_params_sub = orb_subscribe(ORB_ID(parameter_update));
_manual_sub = orb_subscribe(ORB_ID(manual_control_setpoint));
_arming_sub = orb_subscribe(ORB_ID(actuator_armed));
/* rate limit attitude updates to 100Hz */
orb_set_interval(_att_sub, 10);
parameters_update();
/* initialize values of critical structs until first regular update */
_arming.armed = false;
/* get an initial update for all sensor and status data */
vehicle_setpoint_poll();
vehicle_control_mode_poll();
vehicle_manual_poll();
arming_status_poll();
bool reset_yaw_sp = true;
/* wakeup source(s) */
struct pollfd fds[2];
/* Setup of loop */
fds[0].fd = _params_sub;
fds[0].events = POLLIN;
fds[1].fd = _att_sub;
fds[1].events = POLLIN;
while (!_task_should_exit) {
/* wait for up to 500ms for data */
int pret = poll(&fds[0], (sizeof(fds) / sizeof(fds[0])), 100);
/* timed out - periodic check for _task_should_exit, etc. */
if (pret == 0)
continue;
/* this is undesirable but not much we can do - might want to flag unhappy status */
if (pret < 0) {
warn("poll error %d, %d", pret, errno);
continue;
}
perf_begin(_loop_perf);
/* only update parameters if they changed */
if (fds[0].revents & POLLIN) {
/* copy the topic to clear updated flag */
struct parameter_update_s update;
orb_copy(ORB_ID(parameter_update), _params_sub, &update);
parameters_update();
}
/* only run controller if attitude changed */
if (fds[1].revents & POLLIN) {
static uint64_t last_run = 0;
float dt = (hrt_absolute_time() - last_run) / 1000000.0f;
last_run = hrt_absolute_time();
/* guard against too large dt's */
if (dt > 0.02f)
dt = 0.02f;
/* copy attitude topic */
orb_copy(ORB_ID(vehicle_attitude), _att_sub, &_att);
vehicle_setpoint_poll();
vehicle_control_mode_poll();
arming_status_poll();
vehicle_manual_poll();
float yaw_sp_move_rate = 0.0f;
bool publish_att_sp = false;
/* define which input is the dominating control input */
if (_control_mode.flag_control_manual_enabled) {
/* manual input */
if (!_control_mode.flag_control_climb_rate_enabled) {
/* pass throttle directly if not in altitude control mode */
_att_sp.thrust = _manual.throttle;
}
if (_control_mode.flag_control_attitude_enabled) {
/* control attitude, update attitude setpoint depending on mode */
if (_att_sp.thrust < 0.1f) {
// TODO
//if (_status.condition_landed) {
/* reset yaw setpoint if on ground */
// reset_yaw_sp = true;
//}
} else {
if (_manual.yaw < -YAW_DEADZONE || YAW_DEADZONE < _manual.yaw) {
/* move yaw setpoint */
yaw_sp_move_rate = _manual.yaw;
_att_sp.yaw_body = _wrap_pi(_att_sp.yaw_body + yaw_sp_move_rate * dt);
publish_att_sp = true;
}
}
/* reset yaw setpint to current position if needed */
if (reset_yaw_sp) {
reset_yaw_sp = false;
_att_sp.yaw_body = _att.yaw;
publish_att_sp = true;
}
if (!_control_mode.flag_control_velocity_enabled) {
/* update attitude setpoint if not in position control mode */
_att_sp.roll_body = _manual.roll;
_att_sp.pitch_body = _manual.pitch;
publish_att_sp = true;
}
} else {
/* manual rate inputs (ACRO) */
// TODO
/* reset yaw setpoint after ACRO */
reset_yaw_sp = true;
}
} else {
if (!_control_mode.flag_control_auto_enabled) {
/* no control, try to stay on place */
if (!_control_mode.flag_control_velocity_enabled) {
/* no velocity control, reset attitude setpoint */
_att_sp.roll_body = 0.0f;
_att_sp.pitch_body = 0.0f;
publish_att_sp = true;
}
}
/* reset yaw setpoint after non-manual control */
reset_yaw_sp = true;
}
if (publish_att_sp || !_att_sp.R_valid) {
/* controller uses rotation matrix, not euler angles, convert if necessary */
math::EulerAngles euler_sp(_att_sp.roll_body, _att_sp.pitch_body, _att_sp.yaw_body);
math::Dcm R_sp(euler_sp);
for (int i = 0; i < 9; i++) {
_att_sp.R_body[i] = R_sp(i / 3, i % 3);
}
_att_sp.R_valid = true;
}
if (publish_att_sp) {
/* publish the attitude setpoint */
_att_sp.timestamp = hrt_absolute_time();
if (_att_sp_pub > 0) {
orb_publish(ORB_ID(vehicle_attitude_setpoint), _att_sp_pub, &_att_sp);
} else {
_att_sp_pub = orb_advertise(ORB_ID(vehicle_attitude_setpoint), &_att_sp);
}
}
/* desired rotation matrix */
math::Dcm R_des(&_att_sp.R_body[0]);
/* rotation matrix for current state */
math::Dcm R(_att.R);
/* current body angular rates */
math::Vector3 rates(_att.rollspeed, _att.pitchspeed, _att.yawspeed);
/* orientation error between R and R_des */
math::Matrix e_R_m = (R_des.transpose() * R - R.transpose() * R_des).transpose() * 0.5f;
math::Vector3 e_R(-e_R_m(1, 2), e_R_m(0, 2), -e_R_m(0, 1));
/* angular rates setpoint*/
math::Vector3 rates_sp = _K * e_R;
/* feed forward yaw setpoint rate */
rates_sp(2) += yaw_sp_move_rate;
math::Vector3 control = _K_rate * (rates_sp - rates);
/* publish the attitude rates setpoint */
_rates_sp.roll = rates_sp(0);
_rates_sp.pitch = rates_sp(1);
_rates_sp.yaw = rates_sp(2);
_rates_sp.thrust = _att_sp.thrust;
_rates_sp.timestamp = hrt_absolute_time();
if (_rates_sp_pub > 0) {
orb_publish(ORB_ID(vehicle_rates_setpoint), _rates_sp_pub, &_rates_sp);
} else {
_rates_sp_pub = orb_advertise(ORB_ID(vehicle_rates_setpoint), &_rates_sp);
}
/* publish the attitude controls */
_actuators.control[0] = (isfinite(control(0))) ? control(0) : 0.0f;
_actuators.control[1] = (isfinite(control(1))) ? control(1) : 0.0f;
_actuators.control[2] = (isfinite(control(2))) ? control(2) : 0.0f;
_actuators.control[3] = (isfinite(_rates_sp.thrust)) ? _rates_sp.thrust : 0.0f;
_actuators.timestamp = hrt_absolute_time();
if (_actuators_0_pub > 0) {
/* publish the attitude setpoint */
orb_publish(ORB_ID(actuator_controls_0), _actuators_0_pub, &_actuators);
} else {
/* advertise and publish */
_actuators_0_pub = orb_advertise(ORB_ID(actuator_controls_0), &_actuators);
}
}
perf_end(_loop_perf);
}
warnx("exit");
_control_task = -1;
_exit(0);
}
int
MulticopterAttitudeControl::start()
{
ASSERT(_control_task == -1);
/* start the task */
_control_task = task_spawn_cmd("mc_att_control_vector",
SCHED_DEFAULT,
SCHED_PRIORITY_MAX - 5,
2048,
(main_t)&MulticopterAttitudeControl::task_main_trampoline,
nullptr);
if (_control_task < 0) {
warn("task start failed");
return -errno;
}
return OK;
}
int mc_att_control_vector_main(int argc, char *argv[])
{
if (argc < 1)
errx(1, "usage: mc_att_control_vector {start|stop|status}");
if (!strcmp(argv[1], "start")) {
if (att_control::g_control != nullptr)
errx(1, "already running");
att_control::g_control = new MulticopterAttitudeControl;
if (att_control::g_control == nullptr)
errx(1, "alloc failed");
if (OK != att_control::g_control->start()) {
delete att_control::g_control;
att_control::g_control = nullptr;
err(1, "start failed");
}
exit(0);
}
if (!strcmp(argv[1], "stop")) {
if (att_control::g_control == nullptr)
errx(1, "not running");
delete att_control::g_control;
att_control::g_control = nullptr;
exit(0);
}
if (!strcmp(argv[1], "status")) {
if (att_control::g_control) {
errx(0, "running");
} else {
errx(1, "not running");
}
}
warnx("unrecognized command");
return 1;
}
|