129 lines
		
	
	
		
			4.9 KiB
		
	
	
	
		
			C++
		
	
	
			
		
		
	
	
			129 lines
		
	
	
		
			4.9 KiB
		
	
	
	
		
			C++
		
	
	
| /**
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|  * @file testPendulumExplicitEuler.cpp
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|  * @author Duy-Nguyen Ta
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|  */
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| 
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| #include <CppUnitLite/TestHarness.h>
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| #include <gtsam/base/numericalDerivative.h>
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| #include <gtsam/inference/Symbol.h>
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| #include <gtsam_unstable/dynamics/SimpleHelicopter.h>
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| #include "gtsam/base/Vector.h"
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| #include "gtsam/geometry/Pose3.h"
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| 
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| /* ************************************************************************* */
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| using namespace std::placeholders;
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| using namespace gtsam;
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| using namespace gtsam::symbol_shorthand;
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| 
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| const double tol=1e-5;
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| const double h = 0.01;
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| 
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| //const double deg2rad = M_PI/180.0;
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| //Pose3 g1(Rot3::Ypr(deg2rad*10.0, deg2rad*20.0, deg2rad*30.0), Point3(100.0, 200.0, 300.0));
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| Pose3 g1(Rot3(), Point3(100.0, 0.0, 300.0));
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| //Vector6 v1((Vector(6) << 0.1, 0.05, 0.02, 10.0, 20.0, 30.0).finished());
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| Vector6 V1_w((Vector(6) << 0.0, 0.0, M_PI/3, 0.0, 0.0, 30.0).finished());
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| Vector6 V1_g1 = g1.inverse().Adjoint(V1_w);
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| Pose3 g2(g1.expmap(h*V1_g1));
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| //Vector6 v2 = Pose3::Logmap(g1.between(g2));
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| 
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| double mass = 100.0;
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| Vector gamma2 = Vector2(0.0, 0.0);  // no shape
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| Vector u2 = Vector2(0.0, 0.0); // no control at time 2
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| double distT = 1.0; // distance from the body-centered x axis to the big top motor
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| double distR = 5.0; // distance from the body-centered z axis to the small motor
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| Matrix Mass = ((Vector(3) << mass, mass, mass).finished()).asDiagonal();
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| Matrix Inertia = (Vector(6) << 2.0/5.0*mass*distR*distR, 2.0/5.0*mass*distR*distR, 2.0/5.0*mass*distR*distR, mass, mass, mass).finished().asDiagonal();
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| 
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| Vector computeFu(const Vector& gamma, const Vector& control) {
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|   double gamma_r = gamma(0), gamma_p = gamma(1);
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| 
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|   Matrix F = (Matrix(6, 2) << distT*sin(gamma_r), 0.0,
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|                            distT*sin(gamma_p*cos(gamma_r)), 0.0,
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|                            0.0, distR,
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|                            sin(gamma_p)*cos(gamma_r), 0.0,
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|                           -sin(gamma_r), -1.0,
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|                            cos(gamma_p)*sin(gamma_r), 0.0
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|                             ).finished();
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|   return F*control;
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| }
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| 
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| /* ************************************************************************* */
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| TEST( Reconstruction, evaluateError) {
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|   // hard constraints don't need a noise model
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|   Reconstruction constraint(G(2), G(1), V(1), h);
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| 
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|   // verify error function
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|   Matrix H1, H2, H3;
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|   EXPECT(
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|       assert_equal(Z_6x1, constraint.evaluateError(g2, g1, V1_g1, H1, H2, H3), tol));
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| 
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|   std::function<Vector(const Pose3&, const Pose3&, const Vector6&)> f = 
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|     [&constraint](const Pose3& a1, const Pose3& a2, const Vector6& a3) {
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|     return constraint.evaluateError(a1, a2, a3);
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|   };
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| 
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|   Matrix numericalH1 = numericalDerivative31(f, g2, g1, V1_g1, 1e-5);
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| 
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|   Matrix numericalH2 = numericalDerivative32(f, g2, g1, V1_g1, 1e-5);
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| 
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|   Matrix numericalH3 = numericalDerivative33(f, g2, g1, V1_g1, 1e-5);
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| 
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|   EXPECT(assert_equal(numericalH1,H1,1e-5));
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|   EXPECT(assert_equal(numericalH2,H2,1e-5));
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| #ifdef GTSAM_USE_QUATERNIONS // TODO: why is the quaternion version much less accurate??
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|   EXPECT(assert_equal(numericalH3,H3,1e-3));
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| #else
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|   EXPECT(assert_equal(numericalH3,H3,1e-3));
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| #endif
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| }
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| 
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| /* ************************************************************************* */
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| // Implement Newton-Euler equation for rigid body dynamics
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| Vector newtonEuler(const Vector& Vb, const Vector& Fb, const Matrix& Inertia) {
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|   Matrix W = Pose3::adjointMap((Vector(6) << Vb(0), Vb(1), Vb(2), 0., 0., 0.).finished());
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|   Vector dV = Inertia.inverse()*(Fb - W*Inertia*Vb);
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|   return dV;
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| }
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| 
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| TEST( DiscreteEulerPoincareHelicopter, evaluateError) {
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|   Vector Fu = computeFu(gamma2, u2);
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|   Vector fGravity_g1 = Z_6x1;
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|   fGravity_g1.segment<3>(3) = g1.rotation().unrotate(Vector3(0, 0, -mass*9.81));  // gravity force in g1 frame
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|   Vector Fb = Fu+fGravity_g1;
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| 
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|   Vector dV = newtonEuler(V1_g1, Fb, Inertia);
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|   Vector V2_g1 = dV*h + V1_g1;
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|   Pose3 g21 = g2.between(g1);
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|   Vector V2_g2 = g21.Adjoint(V2_g1);  // convert the new velocity to g2's frame
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| 
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|   Vector6 expectedv2(V2_g2);
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| 
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|   // hard constraints don't need a noise model
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|   DiscreteEulerPoincareHelicopter constraint(V(2), V(1), G(2), h,
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|       Inertia, Fu, mass);
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| 
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|   // verify error function
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|   Matrix H1, H2, H3;
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|   EXPECT(assert_equal(Z_6x1, constraint.evaluateError(expectedv2, V1_g1, g2, H1, H2, H3), 1e0));
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| 
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|   std::function<Vector(const Vector6&, const Vector6&, const Pose3&)> f =
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|       [&constraint](const Vector6& a1, const Vector6& a2, const Pose3& a3) {
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|         return constraint.evaluateError(a1, a2, a3);
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|       };
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| 
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|   Matrix numericalH1 = numericalDerivative31(f, expectedv2, V1_g1, g2, 1e-5);
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| 
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|   Matrix numericalH2 = numericalDerivative32(f, expectedv2, V1_g1, g2, 1e-5);
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| 
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|   Matrix numericalH3 = numericalDerivative33(f, expectedv2, V1_g1, g2, 1e-5);
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| 
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|   EXPECT(assert_equal(numericalH1,H1,1e-5));
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|   EXPECT(assert_equal(numericalH2,H2,1e-5));
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|   EXPECT(assert_equal(numericalH3,H3,5e-5));
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| }
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| 
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| /* ************************************************************************* */
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| int main() { TestResult tr; return TestRegistry::runAllTests(tr); }
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| /* ************************************************************************* */
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