-
Notifications
You must be signed in to change notification settings - Fork 311
/
franka_gripper_sim.cpp
474 lines (403 loc) · 18.4 KB
/
franka_gripper_sim.cpp
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
#include <cmath>
#include <memory>
#include <franka_gazebo/franka_gripper_sim.h>
#include <pluginlib/class_list_macros.h>
namespace franka_gazebo {
using actionlib::SimpleActionServer;
using control_msgs::GripperCommandAction;
using franka_gripper::GraspAction;
using franka_gripper::HomingAction;
using franka_gripper::MoveAction;
using franka_gripper::StopAction;
bool FrankaGripperSim::init(hardware_interface::EffortJointInterface* hw, ros::NodeHandle& nh) {
std::string ns = nh.getNamespace();
std::string arm_id;
if (not nh.getParam("arm_id", arm_id)) {
ROS_ERROR_STREAM_NAMED("FrankaGripperSim",
"Could not find required parameter '" << ns << "/arm_id'");
return false;
}
std::string finger1 = arm_id + "_finger_joint1";
std::string finger2 = arm_id + "_finger_joint2";
nh.param<double>("move/width_tolerance", this->tolerance_move_, kDefaultMoveWidthTolerance);
nh.param<double>("gripper_action/width_tolerance", this->tolerance_gripper_action_,
kDefaultGripperActionWidthTolerance);
nh.param<double>("gripper_action/speed", this->speed_default_, kDefaultGripperActionSpeed);
nh.param<double>("grasp/resting_threshold", this->speed_threshold_, kGraspRestingThreshold);
nh.param<int>("grasp/consecutive_samples", this->speed_samples_, kGraspConsecutiveSamples);
try {
this->finger1_ = hw->getHandle(finger1);
this->finger2_ = hw->getHandle(finger2);
} catch (const hardware_interface::HardwareInterfaceException& ex) {
ROS_ERROR_STREAM_NAMED("FrankaGripperSim", "Could not get joint handle(s): " << ex.what());
return false;
}
if (not this->pid1_.initParam(ns + "/finger1/gains")) {
return false;
}
if (not this->pid2_.initParam(ns + "/finger2/gains")) {
return false;
}
pub_.init(nh, "joint_states", 1);
pub_.lock();
pub_.msg_.name = {finger1, finger2};
pub_.unlock();
this->action_stop_ = std::make_unique<SimpleActionServer<StopAction>>(
nh, "stop", boost::bind(&FrankaGripperSim::onStopGoal, this, _1), false);
this->action_stop_->start();
this->action_homing_ = std::make_unique<SimpleActionServer<HomingAction>>(
nh, "homing", boost::bind(&FrankaGripperSim::onHomingGoal, this, _1), false);
this->action_homing_->registerPreemptCallback([&]() {
ROS_INFO_STREAM_NAMED("FrankaGripperSim", "Homing Action cancelled");
this->setState(State::IDLE);
});
this->action_homing_->start();
this->action_move_ = std::make_unique<SimpleActionServer<MoveAction>>(
nh, "move", boost::bind(&FrankaGripperSim::onMoveGoal, this, _1), false);
this->action_move_->registerPreemptCallback([&]() {
ROS_INFO_STREAM_NAMED("FrankaGripperSim", "Moving Action cancelled");
this->setState(State::IDLE);
});
this->action_move_->start();
this->action_grasp_ = std::make_unique<SimpleActionServer<GraspAction>>(
nh, "grasp", boost::bind(&FrankaGripperSim::onGraspGoal, this, _1), false);
this->action_grasp_->registerPreemptCallback([&]() {
ROS_INFO_STREAM_NAMED("FrankaGripperSim", "Grasping Action cancelled");
this->setState(State::IDLE);
});
this->action_grasp_->start();
this->action_gc_ = std::make_unique<SimpleActionServer<GripperCommandAction>>(
nh, "gripper_action", boost::bind(&FrankaGripperSim::onGripperActionGoal, this, _1), false);
this->action_gc_->registerPreemptCallback([&]() {
ROS_INFO_STREAM_NAMED("FrankaGripperSim", "Gripper Command Action cancelled");
this->setState(State::IDLE);
});
this->action_gc_->start();
ROS_INFO_STREAM_NAMED("FrankaGripperSim",
"Successfully initialized Franka Gripper Controller for joints '"
<< finger1 << "' and '" << finger2 << "'");
return true;
}
void FrankaGripperSim::starting(const ros::Time& /*unused*/) {
transition(State::IDLE, Config());
this->pid1_.reset();
this->pid2_.reset();
}
void FrankaGripperSim::update(const ros::Time& now, const ros::Duration& period) {
if (rate_trigger_() and pub_.trylock()) {
pub_.msg_.header.stamp = now;
pub_.msg_.position = {this->finger1_.getPosition(), this->finger2_.getPosition()};
pub_.msg_.velocity = {this->finger1_.getVelocity(), this->finger2_.getVelocity()};
pub_.msg_.effort = {this->finger1_.getEffort(), this->finger2_.getEffort()};
pub_.unlockAndPublish();
}
// Read state threadsafe
double width = this->finger1_.getPosition() + this->finger2_.getPosition();
this->mutex_.lock();
State state = this->state_;
auto tolerance = this->config_.tolerance;
double w_d = this->config_.width_desired;
double dw_d = this->config_.speed_desired * std::copysign(1.0, w_d - width);
this->mutex_.unlock();
if (state == State::IDLE) {
// Track position of other finger to simulate mimicked joints + high damping
control(this->finger1_, this->pid1_, this->finger2_.getPosition(), 0, 0, period);
control(this->finger2_, this->pid2_, this->finger1_.getPosition(), 0, 0, period);
return;
}
// Compute control signal and send to joints
double w1_d = this->finger1_.getPosition() + 0.5 * dw_d * period.toSec();
double w2_d = this->finger2_.getPosition() + 0.5 * dw_d * period.toSec();
// Only in case when we hold we want to add the desired force, in any other state don't add
// anything extra to the command
double f_d = 0;
if (state == State::HOLDING) {
// When an object is grasped, next to the force to apply, also track the other finger
// to not make both fingers drift away from middle simultaneously
w1_d = this->finger2_.getPosition();
w2_d = this->finger1_.getPosition();
std::lock_guard<std::mutex> lock(this->mutex_);
f_d = -this->config_.force_desired / 2.0;
}
control(this->finger1_, this->pid1_, w1_d, 0.5 * dw_d, f_d, period);
control(this->finger2_, this->pid2_, w2_d, 0.5 * dw_d, f_d, period);
if (w_d - tolerance.inner < width and width < w_d + tolerance.outer) {
// Goal reached, update statemachine
if (state == State::MOVING) {
// Done with move motion, switch to idle again
transition(State::IDLE, Config{.width_desired = this->config_.width_desired,
.speed_desired = 0,
.force_desired = 0,
.tolerance = this->config_.tolerance});
}
if (state == State::HOMING) {
if (this->config_.width_desired == 0) {
// Finger now open, first part of homing done, switch direction
setConfig(Config{.width_desired = kMaxFingerWidth,
.speed_desired = this->config_.speed_desired,
.force_desired = this->config_.force_desired,
.tolerance = this->config_.tolerance});
} else {
// Finger now closed again, homing finished
setState(State::IDLE);
}
}
}
if (state == State::GRASPING) {
// Since the velocity signal is noisy it can easily happen that one sample is below the
// threshold To avoid abortion because of noise, we have to read at least N consecutive number
// of samples before interpreting something was grasped (or not)
static int speed_threshold_counter = 0;
double speed = this->finger1_.getVelocity() + this->finger2_.getVelocity();
if (std::abs(speed) <= this->speed_threshold_) {
speed_threshold_counter++;
} else {
speed_threshold_counter = 0;
}
if (speed_threshold_counter >= this->speed_samples_) {
// Done with grasp motion, switch to holding, i.e. keep position & force
transition(State::HOLDING, Config{.width_desired = width,
.speed_desired = 0,
.force_desired = this->config_.force_desired,
.tolerance = this->config_.tolerance});
speed_threshold_counter = 0;
}
}
}
void FrankaGripperSim::control(hardware_interface::JointHandle& joint,
control_toolbox::Pid& pid,
double q_d,
double dq_d,
double f_d,
const ros::Duration& period) {
double error = q_d - joint.getPosition();
double derror = dq_d - joint.getVelocity();
joint.setCommand(pid.computeCommand(error, derror, period) + f_d);
}
void FrankaGripperSim::setState(const State&& state) {
std::lock_guard<std::mutex> lock(this->mutex_);
this->state_ = state;
}
void FrankaGripperSim::setConfig(const Config&& config) {
std::lock_guard<std::mutex> lock(this->mutex_);
this->config_ = config;
}
void FrankaGripperSim::transition(const State&& state, const Config&& config) {
std::lock_guard<std::mutex> lock(this->mutex_);
this->state_ = state;
this->config_ = config;
}
void FrankaGripperSim::interrupt(const std::string& message, const State& except) {
if (except != State::MOVING and this->action_move_ != nullptr and
this->action_move_->isActive()) {
franka_gripper::MoveResult result;
result.success = static_cast<decltype(result.success)>(false);
result.error = message;
this->action_move_->setAborted(result, result.error);
}
if (except != State::GRASPING and this->action_grasp_ != nullptr and
this->action_grasp_->isActive()) {
franka_gripper::GraspResult result;
result.success = static_cast<decltype(result.success)>(false);
result.error = message;
this->action_grasp_->setAborted(result, result.error);
}
if (except != State::HOMING and this->action_homing_ != nullptr and
this->action_homing_->isActive()) {
franka_gripper::HomingResult result;
result.success = static_cast<decltype(result.success)>(false);
result.error = message;
this->action_homing_->setAborted(result, result.error);
}
}
void FrankaGripperSim::waitUntilStateChange() {
State original = this->state_; // copy
ros::Rate rate(30);
while (ros::ok()) {
{
std::lock_guard<std::mutex> lock(this->mutex_);
if (this->state_ != original) {
return;
}
}
rate.sleep();
}
}
void FrankaGripperSim::onStopGoal(const franka_gripper::StopGoalConstPtr& /*goal*/) {
ROS_INFO_STREAM_NAMED("FrankaGripperSim", "Stop Action goal received");
interrupt("Command interrupted, because stop action was called", State::IDLE);
transition(State::IDLE, Config{.width_desired = this->config_.width_desired,
.speed_desired = 0,
.force_desired = 0,
.tolerance = this->config_.tolerance});
franka_gripper::StopResult result;
result.success = static_cast<decltype(result.success)>(true);
action_stop_->setSucceeded(result);
}
void FrankaGripperSim::onHomingGoal(const franka_gripper::HomingGoalConstPtr& /*goal*/) {
ROS_INFO_STREAM_NAMED("FrankaGripperSim", "New Homing Action goal received");
if (this->state_ != State::IDLE) {
this->interrupt("Command interrupted, because new homing action called", State::HOMING);
}
franka_gripper::GraspEpsilon eps;
eps.inner = this->tolerance_move_;
eps.outer = this->tolerance_move_;
transition(
State::HOMING,
Config{.width_desired = 0, .speed_desired = -0.02, .force_desired = 0, .tolerance = eps});
waitUntilStateChange();
if (not this->action_homing_->isActive()) {
// Homing Action was interrupted from another action goal callback and already preempted.
// Don't try to resend result now
return;
}
franka_gripper::HomingResult result;
if (this->state_ != State::IDLE) {
result.success = static_cast<decltype(result.success)>(false);
result.error = "Unexpected state transistion: The gripper not in IDLE as expected";
action_homing_->setAborted(result, result.error);
return;
}
result.success = static_cast<decltype(result.success)>(true);
action_homing_->setSucceeded(result);
}
void FrankaGripperSim::onMoveGoal(const franka_gripper::MoveGoalConstPtr& goal) {
ROS_INFO_STREAM_NAMED("FrankaGripperSim",
"New Move Action Goal received: " << goal->width << " m");
if (goal->speed < 0) {
franka_gripper::MoveResult result;
result.success = static_cast<decltype(result.success)>(false);
result.error = "Only positive speeds allowed";
action_move_->setAborted(result, result.error);
return;
}
if (goal->width < 0 or goal->width > kMaxFingerWidth) {
franka_gripper::MoveResult result;
result.success = static_cast<decltype(result.success)>(false);
result.error = "Target width has to lie between 0 .. " + std::to_string(kMaxFingerWidth);
action_move_->setAborted(result, result.error);
return;
}
if (this->state_ != State::IDLE) {
interrupt("Command interrupted, because new move action called", State::MOVING);
}
franka_gripper::GraspEpsilon eps;
eps.inner = this->tolerance_move_;
eps.outer = this->tolerance_move_;
transition(State::MOVING, Config{.width_desired = goal->width,
.speed_desired = goal->speed,
.force_desired = 0,
.tolerance = eps});
waitUntilStateChange();
if (not this->action_move_->isActive()) {
// Move Action was interrupted from another action goal callback and already preempted.
// Don't try to resend result now
return;
}
franka_gripper::MoveResult result;
if (this->state_ != State::IDLE) {
result.success = static_cast<decltype(result.success)>(false);
result.error = "Unexpected state transistion: The gripper not in IDLE as expected";
action_move_->setAborted(result, result.error);
return;
}
result.success = static_cast<decltype(result.success)>(true);
action_move_->setSucceeded(result);
}
void FrankaGripperSim::onGraspGoal(const franka_gripper::GraspGoalConstPtr& goal) {
ROS_INFO_STREAM_NAMED("FrankaGripperSim",
"New Grasp Action Goal received: " << goal->force << "N");
if (goal->width >= kMaxFingerWidth or goal->width < 0) {
franka_gripper::GraspResult result;
result.success = static_cast<decltype(result.success)>(false);
result.error =
"Can only grasp inside finger width from [0 .. " + std::to_string(kMaxFingerWidth) + "[";
action_grasp_->setAborted(result, result.error);
return;
}
if (goal->speed < 0) {
franka_gripper::GraspResult result;
result.success = static_cast<decltype(result.success)>(false);
result.error = "Only positive speeds allowed";
action_grasp_->setAborted(result, result.error);
return;
}
if (this->state_ != State::IDLE) {
interrupt("Command interrupted, because new grasp action called", State::GRASPING);
}
double width = this->finger1_.getPosition() + this->finger2_.getPosition();
transition(State::GRASPING, Config{.width_desired = goal->width < width ? 0 : kMaxFingerWidth,
.speed_desired = goal->speed,
.force_desired = goal->force,
.tolerance = goal->epsilon});
waitUntilStateChange();
if (not this->action_grasp_->isActive()) {
// Grasping Action was interrupted from another action goal callback and already preempted.
// Don't try to resend result now
return;
}
franka_gripper::GraspResult result;
if (this->state_ != State::HOLDING) {
result.success = static_cast<decltype(result.success)>(false);
result.error = "Unexpected state transistion: The gripper not in HOLDING as expected";
action_grasp_->setAborted(result, result.error);
return;
}
width = this->finger1_.getPosition() + this->finger2_.getPosition(); // recalculate
bool ok = goal->width - goal->epsilon.inner < width and width < goal->width + goal->epsilon.outer;
result.success = static_cast<decltype(result.success)>(ok);
if (not ok) {
result.error = "When the gripper stopped (below speed of " +
std::to_string(this->speed_threshold_) +
" m/s the width between the fingers was not at " + std::to_string(goal->width) +
"m (-" + std::to_string(goal->epsilon.inner) + "m/+" +
std::to_string(goal->epsilon.outer) + "m) but at " + std::to_string(width) + "m";
action_grasp_->setAborted(result, result.error);
setState(State::IDLE);
return;
}
action_grasp_->setSucceeded(result);
}
void FrankaGripperSim::onGripperActionGoal(const control_msgs::GripperCommandGoalConstPtr& goal) {
ROS_INFO_STREAM_NAMED("FrankaGripperSim", "New Gripper Command Action Goal received: "
<< goal->command.max_effort << "N");
// HACK: As one gripper finger is <mimic>, MoveIt!'s trajectory execution manager
// only sends us the width of one finger. Multiply by 2 to get the intended width.
double width = this->finger1_.getPosition() + this->finger2_.getPosition();
franka_gripper::GraspEpsilon eps;
eps.inner = this->tolerance_gripper_action_;
eps.outer = this->tolerance_gripper_action_;
transition(State::GRASPING,
Config{.width_desired = goal->command.position * 2.0 < width ? 0 : kMaxFingerWidth,
.speed_desired = this->speed_default_,
.force_desired = goal->command.max_effort,
.tolerance = eps});
waitUntilStateChange();
if (not this->action_gc_->isActive()) {
// Gripper Action was interrupted from another action goal callback and already preempted.
// Don't try to resend result now
return;
}
control_msgs::GripperCommandResult result;
if (this->state_ != State::HOLDING) {
result.reached_goal = static_cast<decltype(result.reached_goal)>(false);
std::string error = "Unexpected state transistion: The gripper not in HOLDING as expected";
action_gc_->setAborted(result, error);
return;
}
double width_d = goal->command.position * 2.0;
width = this->finger1_.getPosition() + this->finger2_.getPosition(); // recalculate
bool inside_tolerance = width_d - this->tolerance_gripper_action_ < width and
width < width_d + this->tolerance_gripper_action_;
result.position = width;
result.effort = 0;
result.stalled = static_cast<decltype(result.stalled)>(false);
result.reached_goal = static_cast<decltype(result.reached_goal)>(inside_tolerance);
if (not inside_tolerance) {
std::lock_guard<std::mutex> lock(this->mutex_);
this->state_ = State::IDLE;
}
action_gc_->setSucceeded(result);
}
} // namespace franka_gazebo
PLUGINLIB_EXPORT_CLASS(franka_gazebo::FrankaGripperSim, controller_interface::ControllerBase);