rrts/src/rrts.cc

   1 /*
   2  * SPDX-FileCopyrightText: 2021 Jiri Vlasak <jiri.vlasak.2@cvut.cz>
   3  *
   4  * SPDX-License-Identifier: GPL-3.0-only
   5  */
   6
   7 #include <algorithm>
   8 #include <cassert>
   9 #include "rrts.hh"
  10
  11 #ifndef USE_RRTS
  12 #define USE_RRTS 0  // TODO improve, this solution isn't clear.
  13 #endif
  14
  15 namespace rrts {
  16
  17 void
  18 Ter::start()
  19 {
  20         this->_tstart = std::chrono::high_resolution_clock::now();
  21 }
  22
  23 double
  24 Ter::scnt() const
  25 {
  26         auto t = std::chrono::high_resolution_clock::now() - this->_tstart;
  27         auto d = std::chrono::duration_cast<std::chrono::seconds>(t);
  28         return d.count();
  29 }
  30
  31 double
  32 RRTNode::c() const
  33 {
  34         return this->_c;
  35 }
  36
  37 void
  38 RRTNode::c(double c)
  39 {
  40         assert(this->_p != nullptr);
  41         this->_c = c;
  42         this->_cc = this->_p->cc() + c;
  43 }
  44
  45 double
  46 RRTNode::cc() const
  47 {
  48         return this->_cc;
  49 }
  50
  51 RRTNode*
  52 RRTNode::p() const
  53 {
  54         return this->_p;
  55 }
  56
  57 void
  58 RRTNode::p(RRTNode& p, bool can_be_too_close)
  59 {
  60         assert(this != &p);
  61         if (!can_be_too_close) {
  62                 assert(!(std::abs(p.x() - this->x()) < 1e-3
  63                         && std::abs(p.y() - this->y()) < 1e-3
  64                         && std::abs(p.h() - this->h()) < 1e-3));
  65         }
  66         this->_p = &p;
  67         this->p_is_cusp(this->would_be_cusp_if_parent(p));
  68         this->cusp_cnt(p);
  69 }
  70
  71 void
  72 RRTNode::p(RRTNode& p)
  73 {
  74         return this->p(p, false);
  75 }
  76
  77 unsigned int
  78 RRTNode::cusp_cnt() const
  79 {
  80         return this->_cusp_cnt;
  81 }
  82
  83 void
  84 RRTNode::cusp_cnt(RRTNode const& p)
  85 {
  86         this->_cusp_cnt = p.cusp_cnt();
  87         if (this->_p_is_cusp) {
  88                 this->_cusp_cnt++;
  89         }
  90 }
  91
  92 int
  93 RRTNode::st(void)
  94 {
  95         return this->_segment_type;
  96 }
  97
  98 void
  99 RRTNode::st(int st)
 100 {
 101         this->_segment_type = st;
 102 }
 103
 104 bool
 105 RRTNode::p_is_cusp(void) const
 106 {
 107         return this->_p_is_cusp;
 108 }
 109
 110 void
 111 RRTNode::p_is_cusp(bool isit)
 112 {
 113         this->_p_is_cusp = isit;
 114 }
 115
 116 bool
 117 RRTNode::would_be_cusp_if_parent(RRTNode const& p) const
 118 {
 119         if (std::abs(p.sp()) < 1e-3) {
 120                 // It should not be possible to have two zero speed nodes next
 121                 // to each other. In practice, this sometimes happens.
 122                 //assert(std::abs(this->sp()) > 1e-3);
 123                 if (p.p()) {
 124                         if (sgn(p.p()->sp()) != sgn(this->sp())) {
 125                                 return true;
 126                         } else {
 127                                 return false;
 128                         }
 129                 } else {
 130                         return true; // only root has no parent and it is cusp
 131                 }
 132         } else {
 133                 if (std::abs(this->sp()) < 1e-3) {
 134                         return false; // this is cusp, not the parent
 135                 } else if (sgn(p.sp()) != sgn(this->sp())) {
 136                         return true;
 137                 } else {
 138                         return false;
 139                 }
 140         }
 141 }
 142
 143 bool
 144 RRTNode::operator==(RRTNode const& n)
 145 {
 146         return this == &n;
 147 }
 148
 149 void
 150 RRTS::recompute_cc_for_predecessors_and(RRTNode* g)
 151 {
 152         std::vector<RRTNode*> path;
 153         path.reserve(this->_path.size());
 154         while (g != nullptr) {
 155                 path.push_back(g);
 156                 g = g->p();
 157         }
 158         std::reverse(path.begin(), path.end());
 159         for (unsigned int i = 1; i < path.size(); i++) {
 160                 path[i]->c(this->cost_build(*path[i - 1], *path[i]));
 161         }
 162 }
 163
 164 void
 165 RRTS::recompute_path_cc()
 166 {
 167         this->recompute_cc_for_predecessors_and(&this->_goal);
 168 }
 169
 170 double
 171 RRTS::min_gamma_eta() const
 172 {
 173         double ns = this->_nodes.size();
 174         double gamma = pow(log(ns) / ns, 1.0 / 3.0);
 175         return std::min(gamma, this->eta());
 176 }
 177
 178 bool
 179 RRTS::should_continue() const
 180 {
 181         return !this->should_finish();
 182 }
 183
 184 void
 185 RRTS::join_steered(RRTNode* f)
 186 {
 187         while (this->_steered.size() > 0) {
 188                 this->store(this->_steered.front());
 189                 RRTNode* t = &this->_nodes.back();
 190                 t->p(*f);
 191                 t->c(this->cost_build(*f, *t));
 192                 this->_steered.erase(this->_steered.begin());
 193                 f = t;
 194         }
 195 }
 196
 197 bool
 198 RRTS::connect()
 199 {
 200         RRTNode* f = this->_nn;
 201         RRTNode* t = &this->_steered.front();
 202         // Require the steer method to return first node equal to nn:
 203         assert(std::abs(t->x() - f->x()) < 1e-3
 204                 && std::abs(t->y() - f->y()) < 1e-3
 205                 && std::abs(t->h() - f->h()) < 1e-3);
 206         this->_steered.erase(this->_steered.begin());
 207         t = &this->_steered.front();
 208         assert(!(std::abs(t->x() - f->x()) < 1e-3
 209                 && std::abs(t->y() - f->y()) < 1e-3
 210                 && std::abs(t->h() - f->h()) < 1e-3));
 211 #if USE_RRTS
 212         double cost = f->cc() + this->cost_build(*f, *t);
 213         for (auto n: this->nv_) {
 214                 double nc = n->cc() + this->cost_build(*n, *t);
 215                 if (nc < cost) {
 216                         f = n;
 217                         cost = nc;
 218                 }
 219         }
 220         // Check if it's possible to drive from *f to *t. If not, then fallback
 221         // to *f = _nn. This could be also solved by additional steer from *f to
 222         // *t instead of the following code.
 223         this->set_bc_pose_to(*f);
 224         if (!this->_bc.drivable(*t)) {
 225                 f = this->_nn;
 226         }
 227 #endif
 228         this->store(this->_steered.front());
 229         t = &this->_nodes.back();
 230         t->p(*f);
 231         t->c(this->cost_build(*f, *t));
 232         this->_steered.erase(this->_steered.begin());
 233         return true;
 234 }
 235
 236 void
 237 RRTS::rewire()
 238 {
 239         RRTNode *f = &this->_nodes.back();
 240         for (auto n: this->_nv) {
 241                 double fc = f->cc() + this->cost_build(*f, *n);
 242                 this->set_bc_pose_to(*f);
 243                 bool drivable = this->_bc.drivable(*n);
 244                 if (drivable && fc < n->cc()) {
 245                         n->p(*f);
 246                         n->c(this->cost_build(*f, *n));
 247                 }
 248         }
 249 }
 250
 251 bool
 252 RRTS::goal_drivable_from(RRTNode const& f)
 253 {
 254         this->set_bc_pose_to(f);
 255         return this->_bc.drivable(this->_goal);
 256 }
 257
 258 void
 259 RRTS::store(RRTNode n)
 260 {
 261         this->_nodes.push_back(n);
 262 }
 263
 264 double
 265 RRTS::cost_build(RRTNode const& f, RRTNode const& t) const
 266 {
 267         return f.edist(t);
 268 }
 269
 270 double
 271 RRTS::cost_search(RRTNode const& f, RRTNode const& t) const
 272 {
 273         return this->cost_build(f, t);
 274 }
 275
 276 void
 277 RRTS::find_nn(RRTNode const& t)
 278 {
 279         this->_nn = &this->_nodes.front();
 280         this->_cost = this->cost_search(*this->_nn, t);
 281         for (auto& f: this->_nodes) {
 282                 if (this->cost_search(f, t) < this->_cost) {
 283                         this->_nn = &f;
 284                         this->_cost = this->cost_search(f, t);
 285                 }
 286         }
 287 }
 288
 289 void
 290 RRTS::find_nv(RRTNode const& t)
 291 {
 292         this->_nv.clear();
 293         this->_cost = this->min_gamma_eta();
 294         for (auto& f: this->_nodes) {
 295                 if (this->cost_search(f, t) < this->_cost) {
 296                         this->_nv.push_back(&f);
 297                 }
 298         }
 299 }
 300
 301 void
 302 RRTS::compute_path()
 303 {
 304         this->_path.clear();
 305         RRTNode *g = &this->_goal;
 306         if (g->p() == nullptr) {
 307                 return;
 308         }
 309         while (g != nullptr && this->_path.size() < 10000) {
 310                 /* FIXME in ext13
 311                  *
 312                  * There shouldn't be this->_path.size() < 10000 condition.
 313                  * However, the RRTS::compute_path() called from
 314                  * RRTExt13::compute_path tends to re-allocate this->_path
 315                  * infinitely. There's probably node->p() = &node somewhere...
 316                  */
 317                 this->_path.push_back(g);
 318                 g = g->p();
 319         }
 320         std::reverse(this->_path.begin(), this->_path.end());
 321 }
 322
 323 RRTS::RRTS() : _goal(0.0, 0.0, 0.0, 0.0), _gen(std::random_device{}())
 324 {
 325         this->_nodes.reserve(4000000);
 326         this->_steered.reserve(1000);
 327         this->_path.reserve(10000);
 328         this->_nv.reserve(1000);
 329         this->store(RRTNode()); // root
 330 }
 331
 332 void
 333 RRTS::set_bc_pose_to(Pose const& p)
 334 {
 335         this->_bc.set_pose_to(p);
 336 }
 337
 338 void
 339 RRTS::set_bc_to_become(std::string what)
 340 {
 341         this->_bc.become(what);
 342 }
 343
 344 RRTGoal const&
 345 RRTS::goal(void) const
 346 {
 347         return this->_goal;
 348 }
 349
 350 void
 351 RRTS::goal(double x, double y, double b, double e)
 352 {
 353         this->_goal = RRTGoal(x, y, b, e);
 354 }
 355
 356 unsigned int
 357 RRTS::icnt(void) const
 358 {
 359         return this->_icnt;
 360 }
 361
 362 void
 363 RRTS::icnt(unsigned int i)
 364 {
 365         this->_icnt = i;
 366 }
 367
 368 unsigned int
 369 RRTS::icnt_max(void) const
 370 {
 371         return this->_icnt_max;
 372 }
 373
 374 void
 375 RRTS::icnt_max(unsigned int i)
 376 {
 377         this->_icnt_max = i;
 378 }
 379
 380 void
 381 RRTS::tstart(void)
 382 {
 383         this->_ter.start();
 384 }
 385
 386 double
 387 RRTS::scnt() const
 388 {
 389         return this->_ter.scnt();
 390 }
 391
 392 void
 393 RRTS::set_init_pose_to(Pose const& p)
 394 {
 395         this->_nodes.front().x(p.x());
 396         this->_nodes.front().y(p.y());
 397         this->_nodes.front().h(p.h());
 398 }
 399
 400 std::vector<Pose>
 401 RRTS::path() const
 402 {
 403         std::vector<Pose> path;
 404         for (auto n: this->_path) {
 405                 path.push_back(Pose(n->x(), n->y(), n->h()));
 406         }
 407         return path;
 408 }
 409
 410 double
 411 RRTS::path_cost() const
 412 {
 413         return this->_goal.cc();
 414 }
 415
 416 double
 417 RRTS::last_path_cost(void) const
 418 {
 419         if (this->_logged_paths.size() == 0) {
 420                 return 0.0;
 421         }
 422         assert(this->_logged_paths.back().size() > 0);
 423         return this->_logged_paths.back().back().cc();
 424 }
 425
 426 double
 427 RRTS::eta() const
 428 {
 429         return this->_eta;
 430 }
 431
 432 void
 433 RRTS::eta(double e)
 434 {
 435         this->_eta = e;
 436 }
 437
 438 Json::Value
 439 RRTS::json(void) const
 440 {
 441         Json::Value jvo;
 442         unsigned int i = 0, j = 0;
 443         for (auto path: this->_logged_paths) {
 444                 i = 0;
 445                 for (auto n: path) {
 446                         jvo["paths"][j][i][0] = n.x();
 447                         jvo["paths"][j][i][1] = n.y();
 448                         jvo["paths"][j][i][2] = n.h();
 449                         jvo["paths"][j][i][3] = n.sp();
 450                         jvo["paths"][j][i][4] = n.st();
 451                         jvo["paths"][j][i][5] = false;
 452                         if (n.p_is_cusp()) {
 453                                 assert(i > 0);
 454                                 jvo["paths"][j][i - 1][5] = true;
 455                         }
 456                         i++;
 457                 }
 458                 // Initial point is part of the first segment.
 459                 jvo["paths"][j][0][3] = jvo["paths"][j][1][3];
 460                 jvo["paths"][j][0][4] = jvo["paths"][j][1][4];
 461                 // Goal point is part of the last segment.
 462                 jvo["paths"][j][i - 1][3] = jvo["paths"][j][i - 2][3];
 463                 jvo["paths"][j][i - 1][4] = jvo["paths"][j][i - 2][4];
 464                 // --
 465                 jvo["costs"][j] = path.back().cc();
 466                 j++;
 467         }
 468         i = 0;
 469         for (auto n: this->_path) {
 470                 jvo["paths"][j][i][0] = n->x();
 471                 jvo["paths"][j][i][1] = n->y();
 472                 jvo["paths"][j][i][2] = n->h();
 473                 jvo["paths"][j][i][3] = n->sp();
 474                 jvo["paths"][j][i][4] = n->st();
 475                 jvo["paths"][j][i][5] = n->p_is_cusp();
 476                 jvo["path"][i][0] = n->x();
 477                 jvo["path"][i][1] = n->y();
 478                 jvo["path"][i][2] = n->h();
 479                 jvo["path"][i][3] = n->sp();
 480                 jvo["path"][i][4] = n->st();
 481                 jvo["path"][i][5] = false;
 482                 if (n->p_is_cusp()) {
 483                         assert(i > 0);
 484                         jvo["path"][i - 1][5] = true;
 485                 }
 486                 i++;
 487         }
 488         // Initial point is part of the first segment.
 489         jvo["path"][0][3] = jvo["path"][1][3];
 490         jvo["path"][0][4] = jvo["path"][1][4];
 491         // Goal point is part of the last segment.
 492         jvo["path"][i - 1][3] = jvo["path"][i - 2][3];
 493         jvo["path"][i - 1][4] = jvo["path"][i - 2][4];
 494         // --
 495         if (this->_path.size() > 0) {
 496                 jvo["costs"][j] = this->_path.back()->cc();
 497         }
 498         jvo["goal_cc"] = this->_goal.cc(); // TODO remove, use the following
 499         jvo["cost"] = this->path_cost();
 500         jvo["time"] = this->scnt();
 501         return jvo;
 502 }
 503
 504 void
 505 RRTS::json(Json::Value jvi)
 506 {
 507         assert(jvi["init"] != Json::nullValue);
 508         assert(jvi["goal"] != Json::nullValue);
 509         this->set_init_pose_to(Pose(
 510                 jvi["init"][0].asDouble(),
 511                 jvi["init"][1].asDouble(),
 512                 jvi["init"][2].asDouble()));
 513         if (jvi["goal"].size() == 4) {
 514                 this->goal(
 515                         jvi["goal"][0].asDouble(),
 516                         jvi["goal"][1].asDouble(),
 517                         jvi["goal"][2].asDouble(),
 518                         jvi["goal"][3].asDouble());
 519         } else {
 520                 this->goal(
 521                         jvi["goal"][0].asDouble(),
 522                         jvi["goal"][1].asDouble(),
 523                         jvi["goal"][2].asDouble(),
 524                         jvi["goal"][2].asDouble());
 525         }
 526 }
 527
 528 bool
 529 RRTS::next()
 530 {
 531         if (this->icnt() == 0) {
 532                 this->tstart();
 533         }
 534         auto rs = this->sample();
 535 #if 1 // anytime RRTs
 536 {
 537         double d1 = this->cost_search(this->_nodes.front(), rs);
 538         double d2 = this->cost_search(rs, this->_goal);
 539         if (this->last_path_cost() != 0.0 && d1 + d2 > this->last_path_cost()) {
 540                 auto& last_path = this->_logged_paths.back();
 541                 rs = last_path[rand() % last_path.size()];
 542         }
 543 }
 544 #endif
 545         this->find_nn(rs);
 546         this->steer(*this->_nn, rs);
 547         if (this->collide_steered()) {
 548                 return this->should_continue();
 549         }
 550 #if USE_RRTS
 551         this->find_nv(this->_steered.front());
 552 #endif
 553         if (!this->connect()) {
 554                 return this->should_continue();
 555         }
 556 #if USE_RRTS
 557         this->rewire();
 558 #endif
 559         unsigned int ss = this->_steered.size();
 560         this->join_steered(&this->_nodes.back());
 561         RRTNode* just_added = &this->_nodes.back();
 562         bool gf = false;
 563         while (ss > 0 && just_added != nullptr) {
 564                 this->steer(*just_added, this->_goal);
 565                 if (this->collide_steered()) {
 566                         ss--;
 567                         just_added = just_added->p();
 568                         continue;
 569                 }
 570                 // The first of steered is the same as just_added.
 571                 this->_steered.erase(this->_steered.begin());
 572                 this->join_steered(just_added);
 573                 bool gn = this->_goal.edist(this->_nodes.back()) < this->eta();
 574                 bool gd = this->goal_drivable_from(this->_nodes.back());
 575                 if (gn && gd) {
 576                         double nc = this->cost_build(
 577                                 this->_nodes.back(),
 578                                 this->_goal);
 579                         double ncc = this->_nodes.back().cc() + nc;
 580                         if (this->_goal.p() == nullptr
 581                                         || ncc < this->_goal.cc()) {
 582                                 this->_goal.p(this->_nodes.back(), true);
 583                                 this->_goal.c(nc);
 584                                 gf = true;
 585                         }
 586                 }
 587                 ss--;
 588                 just_added = just_added->p();
 589         }
 590         if (gf) {
 591                 this->compute_path();
 592         }
 593         this->_time = this->scnt();
 594         this->icnt(this->icnt() + 1);
 595         return this->should_continue();
 596 }
 597
 598 void
 599 RRTS::reset()
 600 {
 601         if (this->path_cost() != 0.0
 602                         && this->path_cost() < this->last_path_cost()) {
 603                 this->_logged_paths.push_back(std::vector<RRTNode>());
 604                 auto& last_path = this->_logged_paths.back();
 605                 last_path.reserve(this->_path.size());
 606                 RRTNode* p = nullptr;
 607                 for (auto n: this->_path) {
 608                         last_path.push_back(*n);
 609                         if (p != nullptr) {
 610                                 last_path.back().p(*p);
 611                         }
 612                         p = &last_path.back();
 613                 }
 614                 // Test that last path cost matches.
 615                 auto last_path_cost = last_path.back().cc();
 616                 for (unsigned int i = 1; i < last_path.size(); i++) {
 617                         last_path[i].c(this->cost_build(
 618                                 last_path[i - 1],
 619                                 last_path[i]));
 620                 }
 621                 assert(last_path_cost == last_path.back().cc());
 622         }
 623         this->_goal = RRTGoal(
 624                 this->_goal.x(),
 625                 this->_goal.y(),
 626                 this->_goal.b(),
 627                 this->_goal.e());
 628         this->_path.clear();
 629         this->_steered.clear();
 630         this->_nodes.erase(this->_nodes.begin() + 1, this->_nodes.end());
 631         this->_nv.clear();
 632         this->_nn = nullptr;
 633         this->_bc = BicycleCar();
 634 }
 635
 636 } // namespace rrts