GCC Code Coverage Report


Directory: ./
File: src/core/solvers/kkt.cpp
Date: 2025-05-13 10:30:51
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1 ///////////////////////////////////////////////////////////////////////////////
2 // BSD 3-Clause License
3 //
4 // Copyright (C) 2019-2020, LAAS-CNRS, New York University, Max Planck
5 // Gesellschaft,
6 // University of Edinburgh
7 // Copyright note valid unless otherwise stated in individual files.
8 // All rights reserved.
9 ///////////////////////////////////////////////////////////////////////////////
10
11 #include "crocoddyl/core/solvers/kkt.hpp"
12
13 namespace crocoddyl {
14
15 SolverKKT::SolverKKT(std::shared_ptr<ShootingProblem> problem)
16 : SolverAbstract(problem),
17 reg_incfactor_(10.),
18 reg_decfactor_(10.),
19 reg_min_(1e-9),
20 reg_max_(1e9),
21 cost_try_(0.),
22 th_grad_(1e-12),
23 was_feasible_(false) {
24 allocateData();
25 const std::size_t n_alphas = 10;
26 preg_ = 0.;
27 dreg_ = 0.;
28 alphas_.resize(n_alphas);
29 for (std::size_t n = 0; n < n_alphas; ++n) {
30 alphas_[n] = 1. / pow(2., (double)n);
31 }
32 }
33
34 SolverKKT::~SolverKKT() {}
35
36 bool SolverKKT::solve(const std::vector<Eigen::VectorXd>& init_xs,
37 const std::vector<Eigen::VectorXd>& init_us,
38 const std::size_t maxiter, const bool is_feasible,
39 const double) {
40 setCandidate(init_xs, init_us, is_feasible);
41 bool recalc = true;
42 for (iter_ = 0; iter_ < maxiter; ++iter_) {
43 while (true) {
44 try {
45 computeDirection(recalc);
46 } catch (std::exception& e) {
47 recalc = false;
48 if (preg_ == reg_max_) {
49 return false;
50 } else {
51 continue;
52 }
53 }
54 break;
55 }
56
57 expectedImprovement();
58 for (std::vector<double>::const_iterator it = alphas_.begin();
59 it != alphas_.end(); ++it) {
60 steplength_ = *it;
61 try {
62 dV_ = tryStep(steplength_);
63 } catch (std::exception& e) {
64 continue;
65 }
66 dVexp_ = steplength_ * d_[0] + 0.5 * steplength_ * steplength_ * d_[1];
67 if (d_[0] < th_grad_ || !is_feasible_ || dV_ > th_acceptstep_ * dVexp_) {
68 was_feasible_ = is_feasible_;
69 setCandidate(xs_try_, us_try_, true);
70 cost_ = cost_try_;
71 break;
72 }
73 }
74 stoppingCriteria();
75 const std::size_t n_callbacks = callbacks_.size();
76 if (n_callbacks != 0) {
77 for (std::size_t c = 0; c < n_callbacks; ++c) {
78 CallbackAbstract& callback = *callbacks_[c];
79 callback(*this);
80 }
81 }
82 if (was_feasible_ && stop_ < th_stop_) {
83 return true;
84 }
85 }
86 return false;
87 }
88
89 void SolverKKT::computeDirection(const bool recalc) {
90 const std::size_t T = problem_->get_T();
91 if (recalc) {
92 calcDiff();
93 }
94 computePrimalDual();
95 const Eigen::VectorBlock<Eigen::VectorXd, Eigen::Dynamic> p_x =
96 primal_.segment(0, ndx_);
97 const Eigen::VectorBlock<Eigen::VectorXd, Eigen::Dynamic> p_u =
98 primal_.segment(ndx_, nu_);
99
100 std::size_t ix = 0;
101 std::size_t iu = 0;
102 const std::vector<std::shared_ptr<ActionModelAbstract> >& models =
103 problem_->get_runningModels();
104 for (std::size_t t = 0; t < T; ++t) {
105 const std::size_t ndxi = models[t]->get_state()->get_ndx();
106 const std::size_t nui = models[t]->get_nu();
107 dxs_[t] = p_x.segment(ix, ndxi);
108 dus_[t] = p_u.segment(iu, nui);
109 lambdas_[t] = dual_.segment(ix, ndxi);
110 ix += ndxi;
111 iu += nui;
112 }
113 const std::size_t ndxi =
114 problem_->get_terminalModel()->get_state()->get_ndx();
115 dxs_.back() = p_x.segment(ix, ndxi);
116 lambdas_.back() = dual_.segment(ix, ndxi);
117 }
118
119 double SolverKKT::tryStep(const double steplength) {
120 const std::size_t T = problem_->get_T();
121 const std::vector<std::shared_ptr<ActionModelAbstract> >& models =
122 problem_->get_runningModels();
123 for (std::size_t t = 0; t < T; ++t) {
124 const std::shared_ptr<ActionModelAbstract>& m = models[t];
125
126 m->get_state()->integrate(xs_[t], steplength * dxs_[t], xs_try_[t]);
127 if (m->get_nu() != 0) {
128 us_try_[t] = us_[t];
129 us_try_[t] += steplength * dus_[t];
130 }
131 }
132 const std::shared_ptr<ActionModelAbstract> m = problem_->get_terminalModel();
133 m->get_state()->integrate(xs_[T], steplength * dxs_[T], xs_try_[T]);
134 cost_try_ = problem_->calc(xs_try_, us_try_);
135 return cost_ - cost_try_;
136 }
137
138 double SolverKKT::stoppingCriteria() {
139 const std::size_t T = problem_->get_T();
140 std::size_t ix = 0;
141 std::size_t iu = 0;
142 const std::vector<std::shared_ptr<ActionModelAbstract> >& models =
143 problem_->get_runningModels();
144 const std::vector<std::shared_ptr<ActionDataAbstract> >& datas =
145 problem_->get_runningDatas();
146 for (std::size_t t = 0; t < T; ++t) {
147 const std::shared_ptr<ActionDataAbstract>& d = datas[t];
148 const std::size_t ndxi = models[t]->get_state()->get_ndx();
149 const std::size_t nui = models[t]->get_nu();
150
151 dF.segment(ix, ndxi) = lambdas_[t];
152 dF.segment(ix, ndxi).noalias() -= d->Fx.transpose() * lambdas_[t + 1];
153 dF.segment(ndx_ + iu, nui).noalias() = -lambdas_[t + 1].transpose() * d->Fu;
154 ix += ndxi;
155 iu += nui;
156 }
157 const std::size_t ndxi =
158 problem_->get_terminalModel()->get_state()->get_ndx();
159 dF.segment(ix, ndxi) = lambdas_.back();
160 stop_ = (kktref_.segment(0, ndx_ + nu_) + dF).squaredNorm() +
161 kktref_.segment(ndx_ + nu_, ndx_).squaredNorm();
162 return stop_;
163 }
164
165 const Eigen::Vector2d& SolverKKT::expectedImprovement() {
166 d_ = Eigen::Vector2d::Zero();
167 // -grad^T.primal
168 d_(0) = -kktref_.segment(0, ndx_ + nu_).dot(primal_);
169 // -(hessian.primal)^T.primal
170 kkt_primal_.noalias() = kkt_.block(0, 0, ndx_ + nu_, ndx_ + nu_) * primal_;
171 d_(1) = -kkt_primal_.dot(primal_);
172 return d_;
173 }
174
175 const Eigen::MatrixXd& SolverKKT::get_kkt() const { return kkt_; }
176
177 const Eigen::VectorXd& SolverKKT::get_kktref() const { return kktref_; }
178
179 const Eigen::VectorXd& SolverKKT::get_primaldual() const { return primaldual_; }
180
181 const std::vector<Eigen::VectorXd>& SolverKKT::get_dxs() const { return dxs_; }
182
183 const std::vector<Eigen::VectorXd>& SolverKKT::get_dus() const { return dus_; }
184
185 const std::vector<Eigen::VectorXd>& SolverKKT::get_lambdas() const {
186 return lambdas_;
187 }
188
189 std::size_t SolverKKT::get_nx() const { return nx_; }
190
191 std::size_t SolverKKT::get_ndx() const { return ndx_; }
192
193 std::size_t SolverKKT::get_nu() const { return nu_; }
194
195 double SolverKKT::calcDiff() {
196 cost_ = problem_->calc(xs_, us_);
197 cost_ = problem_->calcDiff(xs_, us_);
198
199 // offset on constraint xnext = f(x,u) due to x0 = ref.
200 const std::size_t cx0 =
201 problem_->get_runningModels()[0]->get_state()->get_ndx();
202
203 std::size_t ix = 0;
204 std::size_t iu = 0;
205 const std::size_t T = problem_->get_T();
206 kkt_.block(ndx_ + nu_, 0, ndx_, ndx_).setIdentity();
207 for (std::size_t t = 0; t < T; ++t) {
208 const std::shared_ptr<ActionModelAbstract>& m =
209 problem_->get_runningModels()[t];
210 const std::shared_ptr<ActionDataAbstract>& d =
211 problem_->get_runningDatas()[t];
212 const std::size_t ndxi = m->get_state()->get_ndx();
213 const std::size_t nui = m->get_nu();
214
215 // Computing the gap at the initial state
216 if (t == 0) {
217 m->get_state()->diff(problem_->get_x0(), xs_[0],
218 kktref_.segment(ndx_ + nu_, ndxi));
219 }
220
221 // Filling KKT matrix
222 kkt_.block(ix, ix, ndxi, ndxi) = d->Lxx;
223 kkt_.block(ix, ndx_ + iu, ndxi, nui) = d->Lxu;
224 kkt_.block(ndx_ + iu, ix, nui, ndxi) = d->Lxu.transpose();
225 kkt_.block(ndx_ + iu, ndx_ + iu, nui, nui) = d->Luu;
226 kkt_.block(ndx_ + nu_ + cx0 + ix, ix, ndxi, ndxi) = -d->Fx;
227 kkt_.block(ndx_ + nu_ + cx0 + ix, ndx_ + iu, ndxi, nui) = -d->Fu;
228
229 // Filling KKT vector
230 kktref_.segment(ix, ndxi) = d->Lx;
231 kktref_.segment(ndx_ + iu, nui) = d->Lu;
232 m->get_state()->diff(d->xnext, xs_[t + 1],
233 kktref_.segment(ndx_ + nu_ + cx0 + ix, ndxi));
234
235 ix += ndxi;
236 iu += nui;
237 }
238 const std::shared_ptr<ActionDataAbstract>& df = problem_->get_terminalData();
239 const std::size_t ndxf =
240 problem_->get_terminalModel()->get_state()->get_ndx();
241 kkt_.block(ix, ix, ndxf, ndxf) = df->Lxx;
242 kktref_.segment(ix, ndxf) = df->Lx;
243 kkt_.block(0, ndx_ + nu_, ndx_ + nu_, ndx_) =
244 kkt_.block(ndx_ + nu_, 0, ndx_, ndx_ + nu_).transpose();
245 return cost_;
246 }
247
248 void SolverKKT::computePrimalDual() {
249 primaldual_ = kkt_.lu().solve(-kktref_);
250 primal_ = primaldual_.segment(0, ndx_ + nu_);
251 dual_ = primaldual_.segment(ndx_ + nu_, ndx_);
252 }
253
254 void SolverKKT::increaseRegularization() {
255 preg_ *= reg_incfactor_;
256 if (preg_ > reg_max_) {
257 preg_ = reg_max_;
258 }
259 dreg_ = preg_;
260 }
261
262 void SolverKKT::decreaseRegularization() {
263 preg_ /= reg_decfactor_;
264 if (preg_ < reg_min_) {
265 preg_ = reg_min_;
266 }
267 dreg_ = preg_;
268 }
269
270 void SolverKKT::allocateData() {
271 const std::size_t T = problem_->get_T();
272 dxs_.resize(T + 1);
273 dus_.resize(T);
274 lambdas_.resize(T + 1);
275 xs_try_.resize(T + 1);
276 us_try_.resize(T);
277
278 nx_ = 0;
279 ndx_ = 0;
280 nu_ = 0;
281 const std::size_t nx = problem_->get_nx();
282 const std::size_t ndx = problem_->get_ndx();
283 const std::vector<std::shared_ptr<ActionModelAbstract> >& models =
284 problem_->get_runningModels();
285 for (std::size_t t = 0; t < T; ++t) {
286 const std::shared_ptr<ActionModelAbstract>& model = models[t];
287 if (t == 0) {
288 xs_try_[t] = problem_->get_x0();
289 } else {
290 xs_try_[t] = Eigen::VectorXd::Constant(nx, NAN);
291 }
292 const std::size_t nu = model->get_nu();
293 us_try_[t] = Eigen::VectorXd::Constant(nu, NAN);
294 dxs_[t] = Eigen::VectorXd::Zero(ndx);
295 dus_[t] = Eigen::VectorXd::Zero(nu);
296 lambdas_[t] = Eigen::VectorXd::Zero(ndx);
297 nx_ += nx;
298 ndx_ += ndx;
299 nu_ += nu;
300 }
301 nx_ += nx;
302 ndx_ += ndx;
303 xs_try_.back() = problem_->get_terminalModel()->get_state()->zero();
304 dxs_.back() = Eigen::VectorXd::Zero(ndx);
305 lambdas_.back() = Eigen::VectorXd::Zero(ndx);
306
307 // Set dimensions for kkt matrix and kkt_ref vector
308 kkt_.resize(2 * ndx_ + nu_, 2 * ndx_ + nu_);
309 kkt_.setZero();
310 kktref_.resize(2 * ndx_ + nu_);
311 kktref_.setZero();
312 primaldual_.resize(2 * ndx_ + nu_);
313 primaldual_.setZero();
314 primal_.resize(ndx_ + nu_);
315 primal_.setZero();
316 kkt_primal_.resize(ndx_ + nu_);
317 kkt_primal_.setZero();
318 dual_.resize(ndx_);
319 dual_.setZero();
320 dF.resize(ndx_ + nu_);
321 dF.setZero();
322 }
323
324 } // namespace crocoddyl
325