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])
import os
import time
import sys
sys.path = ["../sympy", "../pydy", "../symengine.py"] + sys.path
import sympy
import symengine
import pydy
from sympy.physics.mechanics.models import n_link_pendulum_on_cart
print(sympy.__file__)
print(symengine.__file__)
print(pydy.__file__)
if (len(sys.argv) > 1):
n = int(sys.argv[1])
else:
n = 4
start = time.time()
sys = n_link_pendulum_on_cart(n, cart_force=False)
end = time.time()
print("%s s" % (end-start))
#print(sys.eom_method.mass_matrix)
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])