src/rrts.cc

   1 #include <algorithm>
   2 #include "rrts.h"
   3
   4 #include "reeds_shepp.h"
   5
   6 template <typename T> int sgn(T val) {
   7         return (T(0) < val) - (val < T(0));
   8 }
   9
  10 RRTNode::RRTNode()
  11 {
  12 }
  13
  14 RRTNode::RRTNode(const BicycleCar &bc) : BicycleCar(bc)
  15 {
  16 }
  17
  18 Obstacle::Obstacle()
  19 {
  20 }
  21
  22 double RRTS::elapsed()
  23 {
  24         std::chrono::duration<double> dt;
  25         dt = std::chrono::duration_cast<std::chrono::duration<double>>(
  26                 std::chrono::high_resolution_clock::now()
  27                 - this->tstart_
  28         );
  29         this->scnt_ = dt.count();
  30         return this->scnt_;
  31 }
  32
  33 bool RRTS::should_stop()
  34 {
  35         // the following counters must be updated, do not comment
  36         this->icnt_++;
  37         this->elapsed();
  38         // decide the stop conditions (maybe comment some lines)
  39         if (this->icnt_ > 999) return true;
  40         if (this->scnt_ > 10) return true;
  41         if (this->gf()) return true;
  42         //if (this->scnt_ - this->pcnt_ > 1) return true;
  43         // but continue by default
  44         return false;
  45 }
  46
  47 bool RRTS::should_continue()
  48 {
  49         // decide the stop conditions (maybe comment some lines)
  50         // it is exact opposite of `should_stop`
  51         //if (this->icnt_ > 999) return false;
  52         if (this->scnt_ > 10) return false;
  53         if (this->gf()) return false;
  54         // and reset pause counter if should continue
  55         this->pcnt_ = this->scnt_;
  56         return true;
  57 }
  58
  59 void RRTS::store_node(RRTNode n)
  60 {
  61         this->nodes().push_back(n);
  62 }
  63
  64 // RRT procedures
  65 std::tuple<bool, unsigned int, unsigned int>
  66 RRTS::collide(std::vector<std::tuple<double, double>> &poly)
  67 {
  68         for (auto &o: this->obstacles())
  69                 if (std::get<0>(::collide(poly, o.poly())))
  70                         return ::collide(poly, o.poly());
  71         return std::make_tuple(false, 0, 0);
  72 }
  73
  74 std::tuple<bool, unsigned int, unsigned int>
  75 RRTS::collide_steered_from(RRTNode &f)
  76 {
  77         std::vector<std::tuple<double, double>> s;
  78         s.push_back(std::make_tuple(f.x(), f.y()));
  79         for (auto &n: this->steered()) {
  80                 s.push_back(std::make_tuple(n.lfx(), n.lfy()));
  81                 s.push_back(std::make_tuple(n.lrx(), n.lry()));
  82                 s.push_back(std::make_tuple(n.rrx(), n.rry()));
  83                 s.push_back(std::make_tuple(n.rfx(), n.rfy()));
  84         }
  85         auto col = this->collide(s);
  86         auto strip_from = this->steered().size() - std::get<1>(col) / 4;
  87         if (std::get<0>(col) && strip_from > 0) {
  88                 while (strip_from-- > 0) {
  89                         this->steered().pop_back();
  90                 }
  91                 return this->collide_steered_from(f);
  92         }
  93         return col;
  94 }
  95
  96 std::tuple<bool, unsigned int, unsigned int>
  97 RRTS::collide_two_nodes(RRTNode &f, RRTNode &t)
  98 {
  99         std::vector<std::tuple<double, double>> p;
 100         p.push_back(std::make_tuple(f.lfx(), f.lfy()));
 101         p.push_back(std::make_tuple(f.lrx(), f.lry()));
 102         p.push_back(std::make_tuple(f.rrx(), f.rry()));
 103         p.push_back(std::make_tuple(f.rfx(), f.rfy()));
 104         p.push_back(std::make_tuple(t.lfx(), t.lfy()));
 105         p.push_back(std::make_tuple(t.lrx(), t.lry()));
 106         p.push_back(std::make_tuple(t.rrx(), t.rry()));
 107         p.push_back(std::make_tuple(t.rfx(), t.rfy()));
 108         return this->collide(p);
 109 }
 110
 111 double RRTS::cost_build(RRTNode &f, RRTNode &t)
 112 {
 113         double cost = 0;
 114         cost = sqrt(pow(t.y() - f.y(), 2) + pow(t.x() - f.x(), 2));
 115         return cost;
 116 }
 117
 118 double RRTS::cost_search(RRTNode &f, RRTNode &t)
 119 {
 120         double cost = 0;
 121         cost = sqrt(pow(t.y() - f.y(), 2) + pow(t.x() - f.x(), 2));
 122         return cost;
 123 }
 124
 125 void RRTS::sample()
 126 {
 127         double x = this->ndx_(this->gen_);
 128         double y = this->ndy_(this->gen_);
 129         double h = this->ndh_(this->gen_);
 130         this->samples().push_back(RRTNode());
 131         this->samples().back().x(x);
 132         this->samples().back().y(y);
 133         this->samples().back().h(h);
 134 }
 135
 136 RRTNode *RRTS::nn(RRTNode &t)
 137 {
 138         RRTNode *nn = &this->nodes().front();
 139         double cost = this->cost_search(*nn, t);
 140         for (auto &f: this->nodes()) {
 141                 if (this->cost_search(f, t) < cost) {
 142                         nn = &f;
 143                         cost = this->cost_search(f, t);
 144                 }
 145         }
 146         return nn;
 147 }
 148
 149 std::vector<RRTNode *> RRTS::nv(RRTNode &t)
 150 {
 151         std::vector<RRTNode *> nv;
 152         double cost = std::min(GAMMA(this->nodes().size()), ETA);
 153         for (auto &f: this->nodes())
 154                 if (this->cost_search(f, t) < cost)
 155                         nv.push_back(&f);
 156         return nv;
 157 }
 158
 159 int cb_rs_steer(double q[4], void *user_data)
 160 {
 161         std::vector<RRTNode> *nodes = (std::vector<RRTNode> *) user_data;
 162         RRTNode *ln = nullptr;
 163         if (nodes->size() > 0)
 164                 ln = &nodes->back();
 165         nodes->push_back(RRTNode());
 166         nodes->back().x(q[0]);
 167         nodes->back().y(q[1]);
 168         nodes->back().h(q[2]);
 169         nodes->back().sp(q[3]);
 170         if (nodes->back().sp() == 0)
 171                 nodes->back().set_t(RRTNodeType::cusp);
 172         else if (ln != nullptr && sgn(ln->sp()) != sgn(nodes->back().sp()))
 173                 ln->set_t(RRTNodeType::cusp);
 174         return 0;
 175 }
 176
 177 void RRTS::steer(RRTNode &f, RRTNode &t)
 178 {
 179         this->steered().clear();
 180         double q0[] = {f.x(), f.y(), f.h()};
 181         double q1[] = {t.x(), t.y(), t.h()};
 182         ReedsSheppStateSpace rsss(f.mtr());
 183         rsss.sample(q0, q1, 0.5, cb_rs_steer, &this->steered());
 184 }
 185
 186 void RRTS::join_steered(RRTNode *f)
 187 {
 188         while (this->steered().size() > 0) {
 189                 this->store_node(this->steered().front());
 190                 RRTNode *t = &this->nodes().back();
 191                 t->p(f);
 192                 t->c(this->cost_build(*f, *t));
 193                 this->steered().erase(this->steered().begin());
 194                 f = t;
 195         }
 196 }
 197
 198 bool RRTS::goal_found(RRTNode &f)
 199 {
 200         bool found = false;
 201         for (auto &g: this->goals()) {
 202                 double cost = this->cost_build(f, g);
 203                 double edist = sqrt(
 204                         pow(f.x() - g.x(), 2)
 205                         + pow(f.y() - g.y(), 2)
 206                 );
 207                 double adist = std::abs(f.h() - g.h());
 208                 if (edist < 0.05 && adist < M_PI / 32) {
 209                         found = true;
 210                         if (g.p() == nullptr || cc(f) + cost < cc(g)) {
 211                                 g.p(&f);
 212                                 g.c(cost);
 213                         }
 214                 }
 215         }
 216         return found;
 217 }
 218
 219 // RRT* procedures
 220 bool RRTS::connect()
 221 {
 222         RRTNode *t = &this->steered().front();
 223         RRTNode *f = this->nn(this->samples().back());
 224         double cost = this->cost_search(*f, *t);
 225         for (auto n: this->nv(*t)) {
 226                 if (
 227                         !std::get<0>(this->collide_two_nodes(*n, *t))
 228                         && this->cost_search(*n, *t) < cost
 229                 ) {
 230                         f = n;
 231                         cost = this->cost_search(*n, *t);
 232                 }
 233         }
 234         this->store_node(this->steered().front());
 235         t = &this->nodes().back();
 236         t->p(f);
 237         t->c(this->cost_build(*f, *t));
 238         t->set_t(RRTNodeType::connected);
 239         return true;
 240 }
 241
 242 void RRTS::rewire()
 243 {
 244         RRTNode *f = &this->nodes().back();
 245         for (auto n: this->nv(*f)) {
 246                 if (
 247                         !std::get<0>(this->collide_two_nodes(*f, *n))
 248                         && cc(*f) + this->cost_search(*f, *n) < cc(*n)
 249                 ) {
 250                         n->p(f);
 251                         n->c(this->cost_build(*f, *n));
 252                 }
 253         }
 254 }
 255
 256 // API
 257 void RRTS::init()
 258 {
 259 }
 260
 261 void RRTS::deinit()
 262 {
 263         this->nodes().clear();
 264         this->samples().clear();
 265         this->steered().clear();
 266         this->store_node(RRTNode()); // root
 267         this->icnt_ = 0;
 268         this->scnt_ = 0;
 269         this->pcnt_ = 0;
 270         this->gf_ = false;
 271 }
 272
 273 std::vector<RRTNode *> RRTS::path()
 274 {
 275         std::vector<RRTNode *> path;
 276         if (this->goals().size() == 0)
 277                 return path;
 278         RRTNode *goal = &this->goals().front();
 279         for (auto &n: this->goals()) {
 280                 if (
 281                         n.p() != nullptr
 282                         && (n.c() < goal->c() || goal->p() == nullptr)
 283                 ) {
 284                         goal = &n;
 285                 }
 286         }
 287         if (goal->p() == nullptr)
 288                 return path;
 289         while (goal != nullptr) {
 290                 path.push_back(goal);
 291                 goal = goal->p();
 292         }
 293         std::reverse(path.begin(), path.end());
 294         return path;
 295 }
 296
 297 bool RRTS::next()
 298 {
 299         if (this->icnt_ == 0)
 300                 this->tstart_ = std::chrono::high_resolution_clock::now();
 301         bool next = true;
 302         if (this->should_stop())
 303                 return false;
 304         this->sample();
 305         this->steer(
 306                 *this->nn(this->samples().back()),
 307                 this->samples().back()
 308         );
 309         if (std::get<0>(this->collide_steered_from(
 310                 *this->nn(this->samples().back())
 311         )))
 312                 return next;
 313         if (!this->connect())
 314                 return next;
 315         this->rewire();
 316         unsigned scnt = this->steered().size();
 317         this->steered().erase(this->steered().begin());
 318         this->join_steered(&this->nodes().back());
 319         RRTNode *just_added = &this->nodes().back();
 320         while (scnt > 0) {
 321                 scnt--;
 322                 for (auto &g: this->goals()) {
 323                         this->steer(*just_added, g);
 324                         if (std::get<0>(this->collide_steered_from(
 325                                 *just_added
 326                         )))
 327                                 continue;
 328                         this->join_steered(just_added);
 329                 }
 330                 this->gf(this->goal_found(this->nodes().back()));
 331                 just_added = just_added->p();
 332         }
 333         return next;
 334 }
 335
 336 void RRTS::set_sample(
 337         double mx, double dx,
 338         double my, double dy,
 339         double mh, double dh
 340 )
 341 {
 342         this->ndx_ = std::normal_distribution<double>(mx, dx);
 343         this->ndy_ = std::normal_distribution<double>(my, dy);
 344         this->ndh_ = std::normal_distribution<double>(mh, dh);
 345 }
 346
 347 Json::Value RRTS::json()
 348 {
 349         Json::Value jvo;
 350         {
 351                 jvo["time"] = this->scnt();
 352         }
 353         {
 354                 jvo["iterations"] = this->icnt();
 355         }
 356         {
 357                 jvo["init"][0] = this->nodes().front().x();
 358                 jvo["init"][1] = this->nodes().front().y();
 359                 jvo["init"][2] = this->nodes().front().h();
 360         }
 361         {
 362                 if (this->path().size() > 0) {
 363                         jvo["cost"] = cc(*this->path().back());
 364                         jvo["goal"][0] = this->path().back()->x();
 365                         jvo["goal"][1] = this->path().back()->y();
 366                         jvo["goal"][2] = this->path().back()->h();
 367                 }
 368         }
 369         {
 370                 unsigned int cu = 0;
 371                 unsigned int co = 0;
 372                 unsigned int pcnt = 0;
 373                 for (auto n: this->path()) {
 374                         jvo["path"][pcnt][0] = n->x();
 375                         jvo["path"][pcnt][1] = n->y();
 376                         jvo["path"][pcnt][2] = n->h();
 377                         if (n->t(RRTNodeType::cusp))
 378                                 cu++;
 379                         if (n->t(RRTNodeType::connected))
 380                                 co++;
 381                         pcnt++;
 382                 }
 383                 jvo["cusps-in-path"] = cu;
 384                 jvo["connecteds-in-path"] = co;
 385         }
 386         {
 387                 unsigned int gcnt = 0;
 388                 for (auto g: this->goals()) {
 389                         jvo["goals"][gcnt][0] = g.x();
 390                         jvo["goals"][gcnt][1] = g.y();
 391                         jvo["goals"][gcnt][2] = g.h();
 392                         gcnt++;
 393                 }
 394         }
 395         {
 396                 unsigned int ocnt = 0;
 397                 for (auto o: this->obstacles()) {
 398                         unsigned int ccnt = 0;
 399                         for (auto c: o.poly()) {
 400                                 jvo["obst"][ocnt][ccnt][0] = std::get<0>(c);
 401                                 jvo["obst"][ocnt][ccnt][1] = std::get<1>(c);
 402                                 ccnt++;
 403                         }
 404                         ocnt++;
 405                 }
 406         }
 407         {
 408                 jvo["nodes"] = (unsigned int) this->nodes().size();
 409         }
 410         //{
 411         //        unsigned int ncnt = 0;
 412         //        for (auto n: this->nodes()) {
 413         //                jvo["nodes_x"][ncnt] = n.x();
 414         //                jvo["nodes_y"][ncnt] = n.y();
 415         //                //jvo["nodes_h"][ncnt] = n.h();
 416         //                ncnt++;
 417         //        }
 418         //}
 419         return jvo;
 420 }
 421
 422 RRTS::RRTS()
 423         : gen_(std::random_device{}())
 424 {
 425         this->goals().reserve(100);
 426         this->nodes().reserve(4000000);
 427         this->samples().reserve(1000);
 428         this->steered().reserve(20000);
 429         this->store_node(RRTNode()); // root
 430 }
 431
 432 double cc(RRTNode &t)
 433 {
 434         RRTNode *n = &t;
 435         double cost = 0;
 436         while (n != nullptr) {
 437                 cost += n->c();
 438                 n = n->p();
 439         }
 440         return cost;
 441 }