// Copyright 2023 DeepMind Technologies Limited // // Licensed under the Apache License, Version 2.0 (the "License"); // you may not use this file except in compliance with the License. // You may obtain a copy of the License at // // http://www.apache.org/licenses/LICENSE-2.0 // // Unless required by applicable law or agreed to in writing, software // distributed under the License is distributed on an "AS IS" BASIS, // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. // See the License for the specific language governing permissions and // limitations under the License. // Tests for the PID controller plugin #include #include #include #include #include #include #include #include #include #include "test/fixture.h" namespace mujoco { namespace { using PidTest = PluginTest; using ::testing::DoubleNear; using ::testing::HasSubstr; using ::testing::IsNull; using ::testing::NotNull; TEST_F(PidTest, PGain) { constexpr absl::string_view kModelXml = R"( )"; char error[1024] = {0}; mjModel* m = LoadModelFromString(kModelXml, error, sizeof(error)); ASSERT_THAT(m, NotNull()) << error; absl::Cleanup m_deleter = [m] { mj_deleteModel(m); }; EXPECT_EQ(m->plugin_statenum[0], 0) << "Plugin should have no state variables"; EXPECT_EQ(m->actuator_actnum[0], 0) << "Plugin should have no activation variables"; mjData* d = mj_makeData(m); absl::Cleanup d_deleter = [d] { mj_deleteData(d); }; // apply the same ctrl to both actuators and see if the same qpos results d->ctrl[0] = 1.0; d->ctrl[1] = 1.0; mj_step(m, d); EXPECT_EQ(d->actuator_force[0], d->actuator_force[1]); EXPECT_EQ(d->qfrc_actuator[0], d->qfrc_actuator[1]); EXPECT_EQ(d->qpos[0], d->qpos[1]); } TEST_F(PidTest, PGainWithFilterExact) { constexpr absl::string_view kModelXml = R"( )"; char error[1024] = {0}; mjModel* m = LoadModelFromString(kModelXml, error, sizeof(error)); ASSERT_THAT(m, NotNull()) << error; absl::Cleanup m_deleter = [m] { mj_deleteModel(m); }; EXPECT_EQ(m->plugin_statenum[0], 0) << "Plugin should have no state variables"; EXPECT_EQ(m->actuator_actnum[0], 1) << "Plugin should have one activation variable"; mjData* d = mj_makeData(m); absl::Cleanup d_deleter = [d] { mj_deleteData(d); }; // apply the same ctrl to both actuators and see if the same qpos results d->ctrl[0] = 1.0; d->ctrl[1] = 1.0; for (int i = 0; i < 2; i++) { mj_step(m, d); EXPECT_EQ(d->actuator_force[0], d->actuator_force[1]); EXPECT_EQ(d->qfrc_actuator[0], d->qfrc_actuator[1]); EXPECT_EQ(d->qpos[0], d->qpos[1]); } } TEST_F(PidTest, SlewMaxRate) { constexpr absl::string_view kModelXml = R"( )"; char error[1024] = {0}; mjModel* m = LoadModelFromString(kModelXml, error, sizeof(error)); ASSERT_THAT(m, NotNull()) << error; absl::Cleanup m_deleter = [m] { mj_deleteModel(m); }; // having a slew rate means that there should be one extra state variable // for the plugin. EXPECT_EQ(m->actuator_actnum[0], 1); mjData* d = mj_makeData(m); absl::Cleanup d_deleter = [d] { mj_deleteData(d); }; // going from ctrl=0.0 to ctrl=1.0 immediately should be equivalent to slowly // incrementing the setpoint d->ctrl[0] = d->ctrl[1] = 0.0; mj_step(m, d); mjtNum max_slew_rate = 0.75; for (int i = 0; i < 2; i++) { d->ctrl[0] = 1.0; d->ctrl[1] = d->time * max_slew_rate; mj_step(m, d); EXPECT_EQ(d->actuator_force[0], d->actuator_force[1]) << "actuator_force mismatch at step " << i; EXPECT_EQ(d->qfrc_actuator[0], d->qfrc_actuator[1]) << "qfrc_actuator mismatch at step " << i; EXPECT_EQ(d->qpos[0], d->qpos[1]) << "qpos mismatch at step " << i; } } TEST_F(PidTest, IntegratedVelocitySlewMaxRate) { constexpr absl::string_view kModelXml = R"( )"; char error[1024] = {0}; mjModel* m = LoadModelFromString(kModelXml, error, sizeof(error)); ASSERT_THAT(m, NotNull()) << error; absl::Cleanup m_deleter = [m] { mj_deleteModel(m); }; // having a slew rate means that there should be one extra state variable // for the plugin. ASSERT_EQ(m->actuator_actnum[0], 1); // The integrated-velocity controller should have one activation variable too. ASSERT_EQ(m->actuator_actnum[1], 1); mjData* d = mj_makeData(m); absl::Cleanup d_deleter = [d] { mj_deleteData(d); }; // going from ctrl=0.0 to ctrl=1.0 immediately should be equivalent to using // an integrated-velocity controller, with actearly = true d->ctrl[0] = d->ctrl[1] = 0.0; mj_step(m, d); mjtNum max_slew_rate = 0.75; for (int i = 0; i < 2; i++) { d->ctrl[0] = 1.0; d->ctrl[1] = max_slew_rate; mj_step(m, d); EXPECT_EQ(d->act[0], d->act[1]) << "act mismatch at step " << i; EXPECT_EQ(d->actuator_force[0], d->actuator_force[1]) << "actuator_force mismatch at step " << i; EXPECT_EQ(d->qfrc_actuator[0], d->qfrc_actuator[1]) << "qfrc_actuator mismatch at step " << i; EXPECT_EQ(d->qpos[0], d->qpos[1]) << "qpos mismatch at step " << i; } } TEST_F(PidTest, SlewMaxRateUsesFirstCtrl) { constexpr absl::string_view kModelXml = R"( )"; char error[1024] = {0}; mjModel* m = LoadModelFromString(kModelXml, error, sizeof(error)); ASSERT_THAT(m, NotNull()) << error; absl::Cleanup m_deleter = [m] { mj_deleteModel(m); }; mjData* d = mj_makeData(m); absl::Cleanup d_deleter = [d] { mj_deleteData(d); }; // When starting with ctrl = 1.0, there shouldn't be a slew rate restriction d->ctrl[0] = 1.0; mj_forward(m, d); EXPECT_EQ(d->actuator_force[0], 4.0); } TEST_F(PidTest, ITerm) { constexpr absl::string_view kModelXml = R"( )"; char error[1024] = {0}; mjModel* m = LoadModelFromString(kModelXml, error, sizeof(error)); ASSERT_THAT(m, NotNull()) << error; absl::Cleanup m_deleter = [m] { mj_deleteModel(m); }; // only the actuators with an I term should have state. EXPECT_EQ(m->actuator_actnum[0], 0); EXPECT_EQ(m->actuator_actnum[1], 1); EXPECT_EQ(m->actuator_actnum[2], 1); mjData* d = mj_makeData(m); absl::Cleanup d_deleter = [d] { mj_deleteData(d); }; // when applying a constant 1.0 control for a while: // - the PD controller should settle to 1.0 - m*g / kp // - the unclamped PID controller should reach 1.0 // - the clamped PID controller should reach 1.0 - (m*g - imax) / kp d->ctrl[0] = d->ctrl[1] = d->ctrl[2] = 1.0; for (int i = 0; i < 10000; i++) { mj_step(m, d); } EXPECT_THAT(d->qpos[0], DoubleNear(1.0 - 10 / 40.0, 1e-5)); EXPECT_THAT(d->qpos[1], DoubleNear(1.0, 1e-5)); EXPECT_THAT(d->qpos[2], DoubleNear(1.0 - (10 - 0.125 * 40.0) / 40.0, 1e-5)); } TEST_F(PidTest, FiniteDifferencing) { constexpr absl::string_view kModelXml = R"( )"; char error[1024] = {0}; mjModel* m = LoadModelFromString(kModelXml, error, sizeof(error)); ASSERT_THAT(m, NotNull()) << error; absl::Cleanup m_deleter = [m] { mj_deleteModel(m); }; // actuators with an I term and max slew rate should have 2 activation // variables. ASSERT_EQ(m->actuator_actnum[0], 2); mjData* d = mj_makeData(m); absl::Cleanup d_deleter = [d] { mj_deleteData(d); }; d->ctrl[0] = 1.0; mj_step(m, d); EXPECT_NE(d->act[0], 0); mjtNum state_before_finite_differencing = d->act[0]; std::vector A((2*m->nv+m->na) * (2*m->nv+m->na), 0); std::vector B((2*m->nv+m->na) * m->nu, 0); std::vector C((m->nsensordata) * (2*m->nv+m->na), 0); std::vector D((m->nsensordata) * m->nu, 0); mjd_transitionFD(m, d, /*eps=*/1e-3, /*flg_centered=*/true, A.data(), B.data(), C.data(), D.data()); EXPECT_EQ(d->act[0], state_before_finite_differencing) << "mjd_transitionFD should not change actuator plugin state."; } TEST_F(PidTest, CtrlClamp) { constexpr absl::string_view kModelXml = R"( )"; char error[1024] = {0}; mjModel* m = LoadModelFromString(kModelXml, error, sizeof(error)); ASSERT_THAT(m, NotNull()) << error; absl::Cleanup m_deleter = [m] { mj_deleteModel(m); }; mjData* d = mj_makeData(m); absl::Cleanup d_deleter = [d] { mj_deleteData(d); }; // when applying a constant 1.0 control for a while, control should be clamped // to 0.75, and the body should reach that point. d->ctrl[0] = 1.0; for (int i = 0; i < 10000; i++) { mj_step(m, d); } EXPECT_THAT(d->qpos[0], DoubleNear(0.75, 1e-5)); // when applying 0, it should be clamped to 0.25 d->ctrl[0] = 0.0; for (int i = 0; i < 10000; i++) { mj_step(m, d); } EXPECT_THAT(d->qpos[0], DoubleNear(0.25, 1e-5)); } TEST_F(PidTest, CopyData) { constexpr absl::string_view kModelXml = R"( )"; char error[1024] = {0}; mjModel* m = LoadModelFromString(kModelXml, error, sizeof(error)); ASSERT_THAT(m, NotNull()) << error; absl::Cleanup m_deleter = [m] { mj_deleteModel(m); }; mjData* d1 = mj_makeData(m); absl::Cleanup d1_deleter = [d1] { mj_deleteData(d1); }; d1->ctrl[0] = d1->ctrl[1] = -1.0; for (int i = 0; i < 3; i++) { mj_step(m, d1); } mjData* d2 = mj_copyData(nullptr, m, d1); absl::Cleanup d2_deleter = [d2] { mj_deleteData(d2); }; mj_step(m, d1); mj_step(m, d2); EXPECT_EQ(d1->qpos[0], d2->qpos[0]); EXPECT_EQ(d1->qpos[1], d2->qpos[1]); } TEST_F(PidTest, MultipleActuatorsSamePlugin) { constexpr absl::string_view kModelXml = R"( )"; char error[1024] = {0}; mjModel* m = LoadModelFromString(kModelXml, error, sizeof(error)); ASSERT_THAT(m, NotNull()) << error; absl::Cleanup m_deleter = [m] { mj_deleteModel(m); }; // having a slew rate means that there should be one extra state variable // for the plugin. EXPECT_EQ(m->actuator_actnum[0], 1); EXPECT_EQ(m->actuator_actnum[1], 1); mjData* d = mj_makeData(m); absl::Cleanup d_deleter = [d] { mj_deleteData(d); }; // Set different ctrls for the two actuators, and check that they're // independent. d->ctrl[0] = 1.0; d->ctrl[1] = -1.0; for (int i = 0; i < 2; i++) { mj_step(m, d); EXPECT_EQ(d->actuator_force[0], -d->actuator_force[1]) << "actuator_force mismatch at step " << i; EXPECT_EQ(d->qfrc_actuator[0], -d->qfrc_actuator[1]) << "qfrc_actuator mismatch at step " << i; EXPECT_EQ(d->qpos[0], -d->qpos[1]) << "qpos mismatch at step " << i; } } TEST_F(PidTest, InvalidClamp) { constexpr absl::string_view kModelXml = R"( )"; char error[1024] = {0}; mjModel* m = LoadModelFromString(kModelXml, error, sizeof(error)); EXPECT_THAT(m, IsNull()); EXPECT_THAT(std::string_view(error), HasSubstr("plugin")); EXPECT_THAT(std::string_view(error), HasSubstr("imax")); } TEST_F(PidTest, InvalidSlew) { constexpr absl::string_view kModelXml = R"( )"; char error[1024] = {0}; mjModel* m = LoadModelFromString(kModelXml, error, sizeof(error)); ASSERT_THAT(m, IsNull()); EXPECT_THAT(std::string_view(error), HasSubstr("plugin")); EXPECT_THAT(std::string_view(error), HasSubstr("slewmax")); } TEST_F(PidTest, WrongActdim) { // XML where PLACEHOLDER is going to be replaced with various things constexpr absl::string_view kBaseXml = R"( )"; char error[1024] = {0}; { std::string no_actdim = absl::StrReplaceAll(kBaseXml, {{"PLACEHOLDER", ""}}); mjModel* m = LoadModelFromString(no_actdim, error, sizeof(error)); EXPECT_THAT(m, IsNull()); EXPECT_THAT(std::string_view(error), HasSubstr("actdim=\"1\"")); } { std::string big_actdim = absl::StrReplaceAll(kBaseXml, {{"PLACEHOLDER", "actdim=\"2\""}}); mjModel* m = LoadModelFromString(big_actdim, error, sizeof(error)); EXPECT_THAT(m, IsNull()); EXPECT_THAT(std::string_view(error), HasSubstr("actdim=\"1\"")); } { std::string dyntype_integrator = absl::StrReplaceAll( kBaseXml, {{"PLACEHOLDER", "dyntype=\"integrator\" actdim=\"1\""}}); mjModel* m = LoadModelFromString(dyntype_integrator, error, sizeof(error)); EXPECT_THAT(m, IsNull()); EXPECT_THAT(std::string_view(error), HasSubstr("actdim=\"2\"")); } } // Regression test: loading models with PID plugin and keyframes used to crash. TEST_F(PidTest, Keyframe) { constexpr absl::string_view kModelXml = R"( )"; char error[1024] = {0}; mjModel* m = LoadModelFromString(kModelXml, error, sizeof(error)); ASSERT_THAT(m, NotNull()) << error; absl::Cleanup m_deleter = [m] { mj_deleteModel(m); }; // having a slew rate means that there should be one extra state variable // for the plugin. EXPECT_EQ(m->actuator_actnum[0], 1); EXPECT_EQ(m->na, 1); ASSERT_EQ(m->nkey, 1); EXPECT_EQ(m->key_act[0], 1.0); mjData* d = mj_makeData(m); absl::Cleanup d_deleter = [d] { mj_deleteData(d); }; mj_resetDataKeyframe(m, d, 0); EXPECT_EQ(d->act[0], 1.0); } } // namespace } // namespace mujoco