| import sympy.physics.mechanics.models as models | |
| from sympy import (cos, sin, Matrix, symbols, zeros) | |
| from sympy.simplify.simplify import simplify | |
| from sympy.physics.mechanics import (dynamicsymbols) | |
| def test_multi_mass_spring_damper_inputs(): | |
| c0, k0, m0 = symbols("c0 k0 m0") | |
| g = symbols("g") | |
| v0, x0, f0 = dynamicsymbols("v0 x0 f0") | |
| kane1 = models.multi_mass_spring_damper(1) | |
| massmatrix1 = Matrix([[m0]]) | |
| forcing1 = Matrix([[-c0*v0 - k0*x0]]) | |
| assert simplify(massmatrix1 - kane1.mass_matrix) == Matrix([0]) | |
| assert simplify(forcing1 - kane1.forcing) == Matrix([0]) | |
| kane2 = models.multi_mass_spring_damper(1, True) | |
| massmatrix2 = Matrix([[m0]]) | |
| forcing2 = Matrix([[-c0*v0 + g*m0 - k0*x0]]) | |
| assert simplify(massmatrix2 - kane2.mass_matrix) == Matrix([0]) | |
| assert simplify(forcing2 - kane2.forcing) == Matrix([0]) | |
| kane3 = models.multi_mass_spring_damper(1, True, True) | |
| massmatrix3 = Matrix([[m0]]) | |
| forcing3 = Matrix([[-c0*v0 + g*m0 - k0*x0 + f0]]) | |
| assert simplify(massmatrix3 - kane3.mass_matrix) == Matrix([0]) | |
| assert simplify(forcing3 - kane3.forcing) == Matrix([0]) | |
| kane4 = models.multi_mass_spring_damper(1, False, True) | |
| massmatrix4 = Matrix([[m0]]) | |
| forcing4 = Matrix([[-c0*v0 - k0*x0 + f0]]) | |
| assert simplify(massmatrix4 - kane4.mass_matrix) == Matrix([0]) | |
| assert simplify(forcing4 - kane4.forcing) == Matrix([0]) | |
| def test_multi_mass_spring_damper_higher_order(): | |
| c0, k0, m0 = symbols("c0 k0 m0") | |
| c1, k1, m1 = symbols("c1 k1 m1") | |
| c2, k2, m2 = symbols("c2 k2 m2") | |
| v0, x0 = dynamicsymbols("v0 x0") | |
| v1, x1 = dynamicsymbols("v1 x1") | |
| v2, x2 = dynamicsymbols("v2 x2") | |
| kane1 = models.multi_mass_spring_damper(3) | |
| massmatrix1 = Matrix([[m0 + m1 + m2, m1 + m2, m2], | |
| [m1 + m2, m1 + m2, m2], | |
| [m2, m2, m2]]) | |
| forcing1 = Matrix([[-c0*v0 - k0*x0], | |
| [-c1*v1 - k1*x1], | |
| [-c2*v2 - k2*x2]]) | |
| assert simplify(massmatrix1 - kane1.mass_matrix) == zeros(3) | |
| assert simplify(forcing1 - kane1.forcing) == Matrix([0, 0, 0]) | |
| def test_n_link_pendulum_on_cart_inputs(): | |
| l0, m0 = symbols("l0 m0") | |
| m1 = symbols("m1") | |
| g = symbols("g") | |
| q0, q1, F, T1 = dynamicsymbols("q0 q1 F T1") | |
| u0, u1 = dynamicsymbols("u0 u1") | |
| kane1 = models.n_link_pendulum_on_cart(1) | |
| massmatrix1 = Matrix([[m0 + m1, -l0*m1*cos(q1)], | |
| [-l0*m1*cos(q1), l0**2*m1]]) | |
| forcing1 = Matrix([[-l0*m1*u1**2*sin(q1) + F], [g*l0*m1*sin(q1)]]) | |
| assert simplify(massmatrix1 - kane1.mass_matrix) == zeros(2) | |
| assert simplify(forcing1 - kane1.forcing) == Matrix([0, 0]) | |
| kane2 = models.n_link_pendulum_on_cart(1, False) | |
| massmatrix2 = Matrix([[m0 + m1, -l0*m1*cos(q1)], | |
| [-l0*m1*cos(q1), l0**2*m1]]) | |
| forcing2 = Matrix([[-l0*m1*u1**2*sin(q1)], [g*l0*m1*sin(q1)]]) | |
| assert simplify(massmatrix2 - kane2.mass_matrix) == zeros(2) | |
| assert simplify(forcing2 - kane2.forcing) == Matrix([0, 0]) | |
| kane3 = models.n_link_pendulum_on_cart(1, False, True) | |
| massmatrix3 = Matrix([[m0 + m1, -l0*m1*cos(q1)], | |
| [-l0*m1*cos(q1), l0**2*m1]]) | |
| forcing3 = Matrix([[-l0*m1*u1**2*sin(q1)], [g*l0*m1*sin(q1) + T1]]) | |
| assert simplify(massmatrix3 - kane3.mass_matrix) == zeros(2) | |
| assert simplify(forcing3 - kane3.forcing) == Matrix([0, 0]) | |
| kane4 = models.n_link_pendulum_on_cart(1, True, False) | |
| massmatrix4 = Matrix([[m0 + m1, -l0*m1*cos(q1)], | |
| [-l0*m1*cos(q1), l0**2*m1]]) | |
| forcing4 = Matrix([[-l0*m1*u1**2*sin(q1) + F], [g*l0*m1*sin(q1)]]) | |
| assert simplify(massmatrix4 - kane4.mass_matrix) == zeros(2) | |
| assert simplify(forcing4 - kane4.forcing) == Matrix([0, 0]) | |
| def test_n_link_pendulum_on_cart_higher_order(): | |
| l0, m0 = symbols("l0 m0") | |
| l1, m1 = symbols("l1 m1") | |
| m2 = symbols("m2") | |
| g = symbols("g") | |
| q0, q1, q2 = dynamicsymbols("q0 q1 q2") | |
| u0, u1, u2 = dynamicsymbols("u0 u1 u2") | |
| F, T1 = dynamicsymbols("F T1") | |
| kane1 = models.n_link_pendulum_on_cart(2) | |
| massmatrix1 = Matrix([[m0 + m1 + m2, -l0*m1*cos(q1) - l0*m2*cos(q1), | |
| -l1*m2*cos(q2)], | |
| [-l0*m1*cos(q1) - l0*m2*cos(q1), l0**2*m1 + l0**2*m2, | |
| l0*l1*m2*(sin(q1)*sin(q2) + cos(q1)*cos(q2))], | |
| [-l1*m2*cos(q2), | |
| l0*l1*m2*(sin(q1)*sin(q2) + cos(q1)*cos(q2)), | |
| l1**2*m2]]) | |
| forcing1 = Matrix([[-l0*m1*u1**2*sin(q1) - l0*m2*u1**2*sin(q1) - | |
| l1*m2*u2**2*sin(q2) + F], | |
| [g*l0*m1*sin(q1) + g*l0*m2*sin(q1) - | |
| l0*l1*m2*(sin(q1)*cos(q2) - sin(q2)*cos(q1))*u2**2], | |
| [g*l1*m2*sin(q2) - l0*l1*m2*(-sin(q1)*cos(q2) + | |
| sin(q2)*cos(q1))*u1**2]]) | |
| assert simplify(massmatrix1 - kane1.mass_matrix) == zeros(3) | |
| assert simplify(forcing1 - kane1.forcing) == Matrix([0, 0, 0]) | |