pEcm = pBtip - .1 * E.y pE1 = pEcm + lE / 2 * E.x vE1 = pE1.time_derivative(N, system) pE2 = pEcm - lE / 2 * E.x vE2 = pE2.time_derivative(N, system) wOA = O.getw_(A) wAB = A.getw_(B) wOC = O.getw_(C) wCD = C.getw_(D) wBD = B.getw_(D) wOE = O.getw_(E) BodyO = Body('BodyO', O, pOcm, mO, Dyadic.build(O, I_main, I_main, I_main), system) #BodyA = Body('BodyA',A,pAcm,mA,Dyadic.build(A,I_leg,I_leg,I_leg),system) #BodyB = Body('BodyB',B,pBcm,mB,Dyadic.build(B,I_leg,I_leg,I_leg),system) #BodyC = Body('BodyC',C,pCcm,mC,Dyadic.build(C,I_leg,I_leg,I_leg),system) #BodyD = Body('BodyD',D,pDcm,mD,Dyadic.build(D,I_leg,I_leg,I_leg),system) BodyE = Body('BodyE', E, pEcm, mE, Dyadic.build(D, I_leg, I_leg, I_leg), system) ParticleA = Particle(pAcm, mA, 'ParticleA') ParticleB = Particle(pBcm, mB, 'ParticleB') ParticleC = Particle(pCcm, mC, 'ParticleC') ParticleD = Particle(pDcm, mD, 'ParticleD') #ParticleE = Particle(pEcm,mE,'ParticleE') system.addforce(-b * wOA, wOA)
pDcm = pCD + lD / 2 * D.x wOMA = O.get_w_to(MA) wOA = O.get_w_to(A) wAB = A.get_w_to(B) wOMC = O.get_w_to(MC) wOC = O.get_w_to(C) wCD = C.get_w_to(D) wBD = B.get_w_to(D) wNMA = N.get_w_to(MA) aNMA = wNMA.time_derivative() wNMC = N.get_w_to(MC) aNMC = wNMC.time_derivative() I_motorA = Dyadic.build(MA, Im, Im, Im) I_motorC = Dyadic.build(MC, Im, Im, Im) BodyO = Body('BodyO', O, pOcm, mO, Dyadic.build(O, I_main, I_main, I_main), system) #BodyA = Body('BodyA',A,pAcm,mA,Dyadic.build(A,I_leg,I_leg,I_leg),system) #BodyB = Body('BodyB',B,pBcm,mB,Dyadic.build(B,I_leg,I_leg,I_leg),system) #BodyC = Body('BodyC',C,pCcm,mC,Dyadic.build(C,I_leg,I_leg,I_leg),system) #BodyD = Body('BodyD',D,pDcm,mD,Dyadic.build(D,I_leg,I_leg,I_leg),system) MotorA = Body('MotorA', MA, pOA, m_motor, I_motorA, system) MotorA = Body('MotorC', MC, pOC, m_motor, I_motorC, system) InductorA = PseudoParticle(0 * MA.x, L, name='InductorA',
B = Frame('B', system) M = Frame('M', system) system.set_newtonian(N) #A.rotate_fixed_axis(N,[0,0,1],qA,system) B.rotate_fixed_axis(N, [0, 0, 1], qB, system) pO = 0 * N.x #wNA = N.get_w_to(A) wNB = N.get_w_to(B) wNA = G * wNB aNA = wNA.time_derivative() #wNB = wB*B.z #aNB = wB_d*B.z I_motor = Dyadic.build(B, Im, Im, Im) I_load = Dyadic.build(B, Il, Il, Il) #Motor = Body('Motor',A,pO,0,I_motor,system) Motor = Body('Motor', B, pO, 0, I_motor, system, wNBody=wNA, alNBody=aNA) Inductor = PseudoParticle(0 * M.x, L, name='Inductor', vCM=i * M.x, aCM=i_d * M.x) #Load = Body('Load',B,pO,0,I_load,system,wNBody = wNB,alNBody = aNB) Load = Body('Load', B, pO, m, I_load, system) #T = kt*(V/R)-kv*G*qB_d T = kt * i
pCcp = pCcm - lw * C.x pC1 = pCcm pC2 = pCcm - l * C.x pE = pC2 - le * E.x #wNC = N.getw_(C) vcm = pCcm.time_derivative() vcp = pCcp.time_derivative() vcp2 = vcp.dot(vcp) ve = pE.time_derivative() ve2 = ve.dot(ve) IC = Dyadic.build(C, I_11, I_11, I_11) Body('BodyC', C, pCcm, mC, IC) vcx = vcp.dot(C.x) vcy = vcp.dot(-C.y) angle_of_attack_C = sympy.atan2(vcy, vcx) vex = ve.dot(E.x) vey = ve.dot(-E.y) angle_of_attack_E = sympy.atan2(vey, vex) #cl = 2*sin(angle_of_attack)*cos(angle_of_attack) #cd = 2*sin(angle_of_attack)**2 #fl = .5*rho*vcp2*cl*A
ini = [initialvalues[item] for item in statevariables] A = Frame('A', system) B = Frame('B', system) C = Frame('C', system) D = Frame('D', system) system.set_newtonian(A) B.rotate_fixed_axis(A, [0, 0, 1], H, system) C.rotate_fixed_axis(B, [1, 0, 0], -L, system) D.rotate_fixed_axis(C, [0, 1, 0], Q, system) pNA = 0 * A.x pAD = pNA + x * A.x + y * A.y pBcm = pAD + r * C.z pDA = pBcm - r * D.z wAD = A.get_w_to(D) II = Dyadic.build(B, J, I, J) BodyD = Body('BodyD', D, pBcm, m, II, system) #ParticleA = Particle(pAcm,mA,'ParticleA',system) #ParticleB = Particle(pBcm,mB,'ParticleB',system) #ParticleC = Particle(pCcm,mC,'ParticleC',system) system.addforcegravity(-g * A.z) f, ma = system.getdynamics()
N = Frame('N',system) A = Frame('A',system) B = Frame('B',system) C = Frame('C',system) system.set_newtonian(N) A.rotate_fixed_axis(N,[1,0,0],qA,system) B.rotate_fixed_axis(A,[0,1,0],qB,system) C.rotate_fixed_axis(B,[0,0,1],qC,system) pCcm=0*N.x w1 = N.get_w_to(C) IC = Dyadic.build(C,Ixx,Iyy,Izz) BodyC = Body('BodyC',C,pCcm,mC,IC) system.addforcegravity(-g*N.y) # system.addforce(1*C.x+2*C.y+3*C.z,w1) points = [1*C.x,0*C.x,1*C.y,0*C.y,1*C.z] f,ma = system.getdynamics() # func1 = system.state_space_pre_invert(f,ma) func1 = system.state_space_post_invert(f,ma) ini = [initialvalues[item] for item in system.get_state_variables()]
system.addforce(-f_aero_C, vctip) # ## Calculating Velocity # # The angular velocity between frames, and the time derivatives of vectors are extremely useful in calculating the equations of motion and for determining many of the forces that need to be applied to your system (damping, drag, etc). Thus, it is useful, once kinematics have been defined, to take or find the derivatives of some of those vectors for calculating linear or angular velocity vectors # # ### Angular Velocity wA3B3 = A3.get_w_to(B3) wB3C3 = B3.get_w_to(C3) wA3S = A3.get_w_to(S) # ### Define Inertias and Bodies # The next several lines compute the inertia dyadics of each body and define a rigid body on each frame. In the case of frame C, we represent the mass as a particle located at point pCcm. IA = Dyadic.build(A3, Ixx_A, Iyy_A, Izz_A) IB = Dyadic.build(B3, Ixx_B, Iyy_B, Izz_B) IC = Dyadic.build(C3, Ixx_C, Iyy_C, Izz_C) IS = Dyadic.build(S, Ixx_S, Iyy_S, Izz_S) BodyA = Body('BodyA', A3, pAcm, mA, IA, system) BodyB = Body('BodyB', B3, pBcm, mB, IB, system) BodyC = Body('BodyC', C3, pCcm, mC, IC, system) BodyS = Body('BodyS', S, pScm, mS, IS, system) # ## Forces and Torques # Forces and torques are added to the system with the generic ```addforce``` method. The first parameter supplied is a vector describing the force applied at a point or the torque applied along a given rotational axis. The second parameter is the vector describing the linear speed (for an applied force) or the angular velocity(for an applied torque) system.addforce(torque * sympy.sin(freq * 2 * sympy.pi * system.t) * A3.z, wA3S)
#f5 = Frame(,system) system.set_newtonian(f1) f2.rotate_fixed_axis(f1,[0,0,1],q1,system) f3.rotate_fixed_axis(f2,[1,0,0],q2,system) f4.rotate_fixed_axis(f3,[0,1,0],q3,system) p0 = 0*f1.x p1 = p0-l1*f4.x v1=p1.time_derivative(f1) wNA = f1.get_w_to(f2) particle1 = Particle(p1,mp1) body1 = Body('body1',f4,p1,mp1,Dyadic.build(f4,1,1,1),system = None) #system.addforce(-b*v1,v1) system.addforcegravity(-g*f1.z) #system.add_spring_force1(k,(q1)*f1.z,wNA) points = [particle1.pCM] points_x = [item.dot(f1.x) for item in points] points_y = [item.dot(f1.y) for item in points] points_z = [item.dot(f1.z) for item in points] output_x = Output(points_x) output_y = Output(points_y) output_z = Output(points_z)
ini = [initialvalues[item] for item in statevariables] N = Frame('N') A = Frame('A') system.set_newtonian(N) A.rotate_fixed_axis_directed(N, [0, 0, 1], q, system) pNA = 0 * N.x pAB = pNA - x * A.y vNA = pNA.time_derivative(N, system) vAB = pAB.time_derivative(N, system) aAB = vAB.time_derivative(N, system) #ParticleA = Particle(pAB,mA,'ParticleA',system) IA = Dyadic.build(A, Ixx_A, Iyy_A, Izz_A) BodyA = Body('BodyA', A, pAB, mA, IA, system) stretch = x - lA direction = -A.y #system.addforce(-b*vAB,vAB) system.addforce(-k * stretch * A.y, vNA) system.addforce(k * stretch * A.y, vAB) #system.add_springforce(k*stretch*A.y,vAB) #system.addforce(b*x_d*A.y,vAB) system.addforcegravity(-g * N.y) x1 = BodyA.pCM.dot(N.x) y1 = BodyA.pCM.dot(N.y) f, ma = system.getdynamics()
M.rotate_fixed_axis(A, [0, 0, 1], qM, system) pO = 0 * N.x pAcm = x * N.x + y * N.y wNA = N.get_w_to(A) wAB = A.get_w_to(B) wAM = A.get_w_to(M) pBcm = pAcm + l * B.x vAcm = pAcm.time_derivative() #wNA = G*wNB #aNA = wNA.time_derivative() #wNB = wB*B.z #aNB = wB_d*B.z I_motor = Dyadic.build(M, Im, Im, Im) I_body = Dyadic.build(A, Ib, Ib, Ib) I_load = Dyadic.build(B, Il, Il, Il) Motor = Body('Motor', M, pAcm, 0, I_motor, system) main_body = Body('main_body', A, pAcm, m_body, I_body, system) Load = Body('Load', B, pBcm, m_pendulum, I_load, system) Inductor = PseudoParticle(0 * Z.x, L, name='Inductor', vCM=i * Z.x, aCM=i_d * Z.x) #Load = Body('Load',B,pO,0,I_load,system,wNBody = wNB,alNBody = aNB)
def init_system(v, drag_direction, time_step): import pynamics from pynamics.frame import Frame from pynamics.variable_types import Differentiable, Constant from pynamics.system import System from pynamics.body import Body from pynamics.dyadic import Dyadic from pynamics.output import Output, PointsOutput from pynamics.particle import Particle import pynamics.integration import logging import sympy import numpy import matplotlib.pyplot as plt from math import pi from scipy import optimize from sympy import sin import pynamics.tanh as tanh from fit_qs import exp_fit import fit_qs # time_step = tstep x = numpy.zeros((7, 1)) friction_perp = x[0] friction_par = x[1] given_b = x[2] given_k = x[3] given_k1 = x[4] given_b1 = x[4] system = System() pynamics.set_system(__name__, system) global_q = True lO = Constant(7 / 1000, 'lO', system) lA = Constant(33 / 1000, 'lA', system) lB = Constant(33 / 1000, 'lB', system) lC = Constant(33 / 1000, 'lC', system) mO = Constant(10 / 1000, 'mA', system) mA = Constant(2.89 / 1000, 'mA', system) mB = Constant(2.89 / 1000, 'mB', system) mC = Constant(2.89 / 1000, 'mC', system) k = Constant(0.209, 'k', system) k1 = Constant(0.209, 'k1', system) friction_perp = Constant(1.2, 'f_perp', system) friction_par = Constant(-0.2, 'f_par', system) b_damping = Constant(given_b, 'b_damping', system) # time_step = 1/00 if v == 0: [ t, tinitial, tfinal, tstep, qAa1, qAb1, qAc1, qAa2, qAb2, qAc2, qAa3, qAb3, qAc3, qBa1, qBb1, qBc1, qBa2, qBb2, qBc2, qBa3, qBb3, qBc3, qCa1, qCb1, qCc1, qCa2, qCb2, qCc2, qCa3, qCb3, qCc3 ] = fit_qs.fit_0_amount(time_step) elif v == 10: [ t, tinitial, tfinal, tstep, qAa1, qAb1, qAc1, qAa2, qAb2, qAc2, qAa3, qAb3, qAc3, qBa1, qBb1, qBc1, qBa2, qBb2, qBc2, qBa3, qBb3, qBc3, qCa1, qCb1, qCc1, qCa2, qCb2, qCc2, qCa3, qCb3, qCc3 ] = fit_qs.fit_10_amount(time_step) elif v == 20: [ t, tinitial, tfinal, tstep, qAa1, qAb1, qAc1, qAa2, qAb2, qAc2, qAa3, qAb3, qAc3, qBa1, qBb1, qBc1, qBa2, qBb2, qBc2, qBa3, qBb3, qBc3, qCa1, qCb1, qCc1, qCa2, qCb2, qCc2, qCa3, qCb3, qCc3 ] = fit_qs.fit_20_amount(time_step) elif v == 30: [ t, tinitial, tfinal, tstep, qAa1, qAb1, qAc1, qAa2, qAb2, qAc2, qAa3, qAb3, qAc3, qBa1, qBb1, qBc1, qBa2, qBb2, qBc2, qBa3, qBb3, qBc3, qCa1, qCb1, qCc1, qCa2, qCb2, qCc2, qCa3, qCb3, qCc3 ] = fit_qs.fit_30_amount(time_step) elif v == 40: [ t, tinitial, tfinal, tstep, qAa1, qAb1, qAc1, qAa2, qAb2, qAc2, qAa3, qAb3, qAc3, qBa1, qBb1, qBc1, qBa2, qBb2, qBc2, qBa3, qBb3, qBc3, qCa1, qCb1, qCc1, qCa2, qCb2, qCc2, qCa3, qCb3, qCc3 ] = fit_qs.fit_40_amount(time_step) elif v == 50: [ t, tinitial, tfinal, tstep, qAa1, qAb1, qAc1, qAa2, qAb2, qAc2, qAa3, qAb3, qAc3, qBa1, qBb1, qBc1, qBa2, qBb2, qBc2, qBa3, qBb3, qBc3, qCa1, qCb1, qCc1, qCa2, qCb2, qCc2, qCa3, qCb3, qCc3 ] = fit_qs.fit_50_amount(time_step) distance = 200 / 1000 nums = int(tfinal / tstep) array_num = numpy.arange(0, nums) array_num1 = numpy.repeat(array_num, nums, axis=0) array_num1.shape = (nums, nums) error_k = array_num1 / 8000 + numpy.ones((nums, nums)) fit_t = t fit_qA = exp_fit(fit_t, qAa1, qAb1, qAc1, qAa2, qAb2, qAc2, qAa3, qAb3, qAc3) fit_qB = exp_fit(fit_t, qBa1, qBb1, qBc1, qBa2, qBb2, qBc2, qBa3, qBb3, qBc3) fit_qC = exp_fit(fit_t, qCa1, qCb1, qCc1, qCa2, qCb2, qCc2, qCa3, qCb3, qCc3) fit_qAd1 = numpy.diff(fit_qA) / numpy.diff(fit_t) fit_qAd = numpy.append(fit_qAd1[0], fit_qAd1) fit_qBd1 = numpy.diff(fit_qB) / numpy.diff(fit_t) fit_qBd = numpy.append(fit_qBd1[0], fit_qBd1) fit_qCd1 = numpy.diff(fit_qC) / numpy.diff(fit_t) fit_qCd = numpy.append(fit_qCd1[0], fit_qCd1) fit_states1 = numpy.stack( (fit_qA, fit_qB, fit_qC, fit_qAd, fit_qBd, fit_qCd), axis=1) fit_states1[:, 0:3] = fit_states1[:, 0:3] - fit_states1[0, 0:3] fit_states = -drag_direction * numpy.deg2rad(fit_states1) # plt.plot(t,fit_states) if drag_direction == -1: zero_shape = fit_states.shape fit_states = numpy.zeros(zero_shape) fit_vel = drag_direction * distance / (tfinal) if qAa1 == 0: fit_vel = 0 fit_v = numpy.ones(t.shape) * fit_vel if qAa1 == 0: fit_d = numpy.ones(t.shape) * fit_vel else: fit_d = drag_direction * numpy.r_[tinitial:distance:tstep * abs(fit_vel)] preload0 = Constant(0 * pi / 180, 'preload0', system) preload1 = Constant(0 * pi / 180, 'preload1', system) preload2 = Constant(0 * pi / 180, 'preload2', system) preload3 = Constant(0 * pi / 180, 'preload3', system) Ixx_O = Constant(1, 'Ixx_O', system) Iyy_O = Constant(1, 'Iyy_O', system) Izz_O = Constant(1, 'Izz_O', system) Ixx_A = Constant(1, 'Ixx_A', system) Iyy_A = Constant(1, 'Iyy_A', system) Izz_A = Constant(1, 'Izz_A', system) Ixx_B = Constant(1, 'Ixx_B', system) Iyy_B = Constant(1, 'Iyy_B', system) Izz_B = Constant(1, 'Izz_B', system) Ixx_C = Constant(1, 'Ixx_C', system) Iyy_C = Constant(1, 'Iyy_C', system) Izz_C = Constant(1, 'Izz_C', system) y, y_d, y_dd = Differentiable('y', system) qO, qO_d, qO_dd = Differentiable('qO', system) qA, qA_d, qA_dd = Differentiable('qA', system) qB, qB_d, qB_dd = Differentiable('qB', system) qC, qC_d, qC_dd = Differentiable('qC', system) initialvalues = {} initialvalues[y] = 0 + 1e-14 initialvalues[y_d] = fit_vel + 1e-14 initialvalues[qO] = 0 + 1e-14 initialvalues[qO_d] = 0 + 1e-14 initialvalues[qA] = fit_states[0, 0] + 1e-14 initialvalues[qA_d] = fit_states[0, 3] + 1e-14 initialvalues[qB] = fit_states[0, 1] + 1e-14 initialvalues[qB_d] = fit_states[0, 4] + 1e-14 initialvalues[qC] = fit_states[0, 2] + 1e-14 initialvalues[qC_d] = fit_states[0, 5] + 1e-14 statevariables = system.get_state_variables() ini = [initialvalues[item] for item in statevariables] N = Frame('N') O = Frame('O') A = Frame('A') B = Frame('B') C = Frame('C') drag_direction = drag_direction velocity = 200 / tfinal / 1000 vSoil = drag_direction * velocity * N.y nSoil = 1 / vSoil.length() * vSoil system.set_newtonian(N) if not global_q: O.rotate_fixed_axis_directed(N, [0, 0, 1], qO, system) A.rotate_fixed_axis_directed(O, [0, 0, 1], qA, system) B.rotate_fixed_axis_directed(A, [0, 0, 1], qB, system) C.rotate_fixed_axis_directed(B, [0, 0, 1], qC, system) else: O.rotate_fixed_axis_directed(N, [0, 0, 1], qO, system) A.rotate_fixed_axis_directed(N, [0, 0, 1], qA, system) B.rotate_fixed_axis_directed(N, [0, 0, 1], qB, system) C.rotate_fixed_axis_directed(N, [0, 0, 1], qC, system) pNO = 0 * N.x + y * N.y pOA = lO * N.x + y * N.y pAB = pOA + lA * A.x pBC = pAB + lB * B.x pCtip = pBC + lC * C.x pOcm = pNO + lO / 2 * N.x pAcm = pOA + lA / 2 * A.x pBcm = pAB + lB / 2 * B.x pCcm = pBC + lC / 2 * C.x wNO = N.getw_(O) wOA = N.getw_(A) wAB = A.getw_(B) wBC = B.getw_(C) IO = Dyadic.build(O, Ixx_O, Iyy_O, Izz_O) IA = Dyadic.build(A, Ixx_A, Iyy_A, Izz_A) IB = Dyadic.build(B, Ixx_B, Iyy_B, Izz_B) IC = Dyadic.build(C, Ixx_C, Iyy_C, Izz_C) BodyO = Body('BodyO', O, pOcm, mO, IO, system) BodyA = Body('BodyA', A, pAcm, mA, IA, system) BodyB = Body('BodyB', B, pBcm, mB, IB, system) BodyC = Body('BodyC', C, pCcm, mC, IC, system) # BodyC = Particle(pCcm,mC,'ParticleC',system) vOcm = pOcm.time_derivative() vAcm = pAcm.time_derivative() vBcm = pBcm.time_derivative() vCcm = pCcm.time_derivative() system.add_spring_force1(k1 + 10000 * (qA + abs(qA)), (qA - qO - preload1) * N.z, wOA) system.add_spring_force1(k + 10000 * (qB + abs(qB)), (qB - qA - preload2) * N.z, wAB) system.add_spring_force1(k + 10000 * (qC + abs(qC)), (qC - qB - preload3) * N.z, wBC) #new Method use nJoint nvAcm = 1 / vAcm.length() * vAcm nvBcm = 1 / vBcm.length() * vBcm nvCcm = 1 / vCcm.length() * vCcm faperp = friction_perp * nvAcm.dot(A.y) * A.y fapar = friction_par * nvAcm.dot(A.x) * A.x system.addforce(-(faperp + fapar), vAcm) fbperp = friction_perp * nvBcm.dot(B.y) * B.y fbpar = friction_par * nvBcm.dot(B.x) * B.x system.addforce(-(fbperp + fbpar), vBcm) fcperp = friction_perp * nvCcm.dot(C.y) * C.y fcpar = friction_par * nvCcm.dot(C.x) * C.x system.addforce(-(fcperp + fcpar), vCcm) system.addforce(-b_damping * wOA, wOA) system.addforce(-b_damping * wAB, wAB) system.addforce(-b_damping * wBC, wBC) eq = [] eq_d = [(system.derivative(item)) for item in eq] eq_d.append(y_d - fit_vel) eq_dd = [(system.derivative(item)) for item in eq_d] f, ma = system.getdynamics() func1 = system.state_space_post_invert(f, ma, eq_dd) points = [pNO, pOA, pAB, pBC, pCtip] constants = system.constant_values return system, f, ma, func1, points, t, ini, constants, b_damping, k, k1, tstep, fit_states
wOA1 = O.get_w_to(A1) wA1A2 = A1.get_w_to(A2) wA2B = A2.get_w_to(B) #wB1B2 = B1.get_w_to(B2) wOC1 = O.get_w_to(C1) wC1C2 = C1.get_w_to(C2) wC2D = C2.get_w_to(D) #wD1D2 = D1.get_w_to(D2) wBD = B.get_w_to(D) wNMA = N.get_w_to(MA) aNMA = wNMA.time_derivative() wNMC = N.get_w_to(MC) aNMC = wNMC.time_derivative() I_motorA = Dyadic.build(MA, Im, Im, Im) I_motorC = Dyadic.build(MC, Im, Im, Im) #BodyO = Body('BodyO',O,pOcm,mO,Dyadic.build(O,I_main,I_main,I_main),system) #BodyA = Body('BodyA',A,pAcm,mA,Dyadic.build(A,I_leg,I_leg,I_leg),system) #BodyB = Body('BodyB',B,pBcm,mB,Dyadic.build(B,I_leg,I_leg,I_leg),system) #BodyC = Body('BodyC',C,pCcm,mC,Dyadic.build(C,I_leg,I_leg,I_leg),system) #BodyD = Body('BodyD',D,pDcm,mD,Dyadic.build(D,I_leg,I_leg,I_leg),system) Particle0 = Particle(pOcm, mO, 'ParticleO') MotorA = Body('MotorA', MA, pOA, m_motor, I_motorA, system) MotorA = Body('MotorC', MC, pOC, m_motor, I_motorC, system) ParticleA1 = Particle(pA1cm, mA / 2, 'ParticleA1') ParticleC1 = Particle(pC1cm, mC / 2, 'ParticleC1') InductorA = PseudoParticle(0 * MA.x,
def Cal_system(initial_states, drag_direction, tinitial, tstep, tfinal, fit_vel, f1, f2): g_k, g_b_damping, g_b_damping1 = [0.30867935, 1.42946955, 1.08464536] system = System() pynamics.set_system(__name__, system) global_q = True lO = Constant(7 / 1000, 'lO', system) lA = Constant(33 / 1000, 'lA', system) lB = Constant(33 / 1000, 'lB', system) lC = Constant(33 / 1000, 'lC', system) mO = Constant(10 / 1000, 'mA', system) mA = Constant(2.89 / 1000, 'mA', system) mB = Constant(2.89 / 1000, 'mB', system) mC = Constant(2.89 / 1000, 'mC', system) k = Constant(g_k, 'k', system) k1 = Constant(0.4, 'k1', system) friction_perp = Constant(f1, 'f_perp', system) friction_par = Constant(f2, 'f_par', system) b_damping = Constant(g_b_damping, 'b_damping', system) b_damping1 = Constant(g_b_damping1, 'b_damping1', system) preload0 = Constant(0 * pi / 180, 'preload0', system) preload1 = Constant(0 * pi / 180, 'preload1', system) preload2 = Constant(0 * pi / 180, 'preload2', system) preload3 = Constant(0 * pi / 180, 'preload3', system) Ixx_O = Constant(1, 'Ixx_O', system) Iyy_O = Constant(1, 'Iyy_O', system) Izz_O = Constant(1, 'Izz_O', system) Ixx_A = Constant(1, 'Ixx_A', system) Iyy_A = Constant(1, 'Iyy_A', system) Izz_A = Constant(1, 'Izz_A', system) Ixx_B = Constant(1, 'Ixx_B', system) Iyy_B = Constant(1, 'Iyy_B', system) Izz_B = Constant(1, 'Izz_B', system) Ixx_C = Constant(1, 'Ixx_C', system) Iyy_C = Constant(1, 'Iyy_C', system) Izz_C = Constant(1, 'Izz_C', system) y, y_d, y_dd = Differentiable('y', system) qO, qO_d, qO_dd = Differentiable('qO', system) qA, qA_d, qA_dd = Differentiable('qA', system) qB, qB_d, qB_dd = Differentiable('qB', system) qC, qC_d, qC_dd = Differentiable('qC', system) fit_states = initial_states initialvalues = {} initialvalues[y] = fit_states[0] initialvalues[y_d] = fit_states[5] initialvalues[qO] = 0 initialvalues[qO_d] = 0 initialvalues[qA] = fit_states[2] initialvalues[qA_d] = fit_states[7] initialvalues[qB] = fit_states[3] initialvalues[qB_d] = fit_states[8] initialvalues[qC] = fit_states[4] initialvalues[qC_d] = fit_states[9] statevariables = system.get_state_variables() ini = [initialvalues[item] for item in statevariables] N = Frame('N') O = Frame('O') A = Frame('A') B = Frame('B') C = Frame('C') system.set_newtonian(N) if not global_q: O.rotate_fixed_axis_directed(N, [0, 0, 1], qO, system) A.rotate_fixed_axis_directed(O, [0, 0, 1], qA, system) B.rotate_fixed_axis_directed(A, [0, 0, 1], qB, system) C.rotate_fixed_axis_directed(B, [0, 0, 1], qC, system) else: O.rotate_fixed_axis_directed(N, [0, 0, 1], qO, system) A.rotate_fixed_axis_directed(N, [0, 0, 1], qA, system) B.rotate_fixed_axis_directed(N, [0, 0, 1], qB, system) C.rotate_fixed_axis_directed(N, [0, 0, 1], qC, system) pNO = 0 * N.x + y * N.y pOA = lO * N.x + y * N.y pAB = pOA + lA * A.x pBC = pAB + lB * B.x pCtip = pBC + lC * C.x pOcm = pNO + lO / 2 * N.x pAcm = pOA + lA / 2 * A.x pBcm = pAB + lB / 2 * B.x pCcm = pBC + lC / 2 * C.x wNO = N.getw_(O) wOA = N.getw_(A) wAB = A.getw_(B) wBC = B.getw_(C) IO = Dyadic.build(O, Ixx_O, Iyy_O, Izz_O) IA = Dyadic.build(A, Ixx_A, Iyy_A, Izz_A) IB = Dyadic.build(B, Ixx_B, Iyy_B, Izz_B) IC = Dyadic.build(C, Ixx_C, Iyy_C, Izz_C) BodyO = Body('BodyO', O, pOcm, mO, IO, system) BodyA = Body('BodyA', A, pAcm, mA, IA, system) BodyB = Body('BodyB', B, pBcm, mB, IB, system) BodyC = Body('BodyC', C, pCcm, mC, IC, system) # vOcm = pOcm.time_derivative() vAcm = pAcm.time_derivative() vBcm = pBcm.time_derivative() vCcm = pCcm.time_derivative() # system.add_spring_force1(k1+10000*(qA+abs(qA)),(qA-qO-preload1)*N.z,wOA) # system.add_spring_force1(k+10000*(qB+abs(qB)),(qB-qA-preload2)*N.z,wAB) # system.add_spring_force1(k+10000*(qC+abs(qC)),(qC-qB-preload3)*N.z,wBC) system.add_spring_force1(k1, (qA - qO - preload1) * N.z, wOA) system.add_spring_force1(k, (qB - qA - preload2) * N.z, wAB) system.add_spring_force1(k, (qC - qB - preload3) * N.z, wBC) #new Method use nJoint nvAcm = 1 / vAcm.length() * vAcm nvBcm = 1 / vBcm.length() * vBcm nvCcm = 1 / vCcm.length() * vCcm vSoil = drag_direction * 1 * N.y nSoil = 1 / vSoil.length() * vSoil if fit_vel == 0: vSoil = 1 * 1 * N.y nSoil = 1 / vSoil.length() * vSoil faperp = friction_perp * nSoil.dot(A.y) * A.y fapar = friction_par * nSoil.dot(A.x) * A.x system.addforce(-(faperp + fapar), vAcm) fbperp = friction_perp * nSoil.dot(B.y) * B.y fbpar = friction_par * nSoil.dot(B.x) * B.x system.addforce(-(fbperp + fbpar), vBcm) fcperp = friction_perp * nSoil.dot(C.y) * C.y fcpar = friction_par * nSoil.dot(C.x) * C.x system.addforce(-(fcperp + fcpar), vCcm) else: faperp = friction_perp * nvAcm.dot(A.y) * A.y fapar = friction_par * nvAcm.dot(A.x) * A.x system.addforce(-(faperp + fapar), vAcm) fbperp = friction_perp * nvBcm.dot(B.y) * B.y fbpar = friction_par * nvBcm.dot(B.x) * B.x system.addforce(-(fbperp + fbpar), vBcm) fcperp = friction_perp * nvCcm.dot(C.y) * C.y fcpar = friction_par * nvCcm.dot(C.x) * C.x system.addforce(-(fcperp + fcpar), vCcm) system.addforce(-b_damping1 * wOA, wOA) system.addforce(-b_damping * wAB, wAB) system.addforce(-b_damping * wBC, wBC) eq = [] eq_d = [(system.derivative(item)) for item in eq] eq_d.append(y_d - fit_vel) eq_dd = [(system.derivative(item)) for item in eq_d] f, ma = system.getdynamics() func1 = system.state_space_post_invert(f, ma, eq_dd) points = [pNO, pOA, pAB, pBC, pCtip] constants = system.constant_values states = pynamics.integration.integrate_odeint(func1, ini, t, args=({ 'constants': constants }, )) points_output = PointsOutput(points, system, constant_values=constants) y = points_output.calc(states) final = numpy.asarray(states[-1, :]) time1 = time.time() points_output.animate(fps=30, movie_name=str(time1) + 'video_1.mp4', lw=2, marker='o', color=(1, 0, 0, 1), linestyle='-') return final, states, y, system
def Cal_robot(direction, given_l, omega1, t1, t2, ini_states, name1, system, video_on, x1): time_a = time.time() pynamics.set_system(__name__, system) given_k, given_b = x1 global_q = True damping_r = 0 tinitial = 0 tfinal = (t1 - t2) / omega1 tstep = 1 / 30 t = numpy.r_[tinitial:tfinal:tstep] tol_1 = 1e-6 tol_2 = 1e-6 lO = Constant(27.5 / 1000, 'lO', system) lR = Constant(40.5 / 1000, 'lR', system) lA = Constant(given_l / 1000, 'lA', system) lB = Constant(given_l / 1000, 'lB', system) lC = Constant(given_l / 1000, 'lC', system) mO = Constant(154.5 / 1000, 'mO', system) mR = Constant(9.282 / 1000, 'mR', system) mA = Constant(given_l * 2.75 * 0.14450000000000002 / 1000, 'mA', system) mB = Constant(given_l * 2.75 * 0.14450000000000002 / 1000, 'mB', system) mC = Constant(given_l * 2.75 * 0.14450000000000002 / 1000, 'mC', system) k = Constant(given_k, 'k', system) friction_perp = Constant(13 / 3, 'f_perp', system) friction_par = Constant(-2 / 3, 'f_par', system) friction_arm_perp = Constant(5.6, 'fr_perp', system) friction_arm_par = Constant(-0.2, 'fr_par', system) b_damping = Constant(given_b, 'b_damping', system) preload0 = Constant(0 * pi / 180, 'preload0', system) preload1 = Constant(0 * pi / 180, 'preload1', system) preload2 = Constant(0 * pi / 180, 'preload2', system) preload3 = Constant(0 * pi / 180, 'preload3', system) Ixx_O = Constant(1, 'Ixx_O', system) Iyy_O = Constant(1, 'Iyy_O', system) Izz_O = Constant(1, 'Izz_O', system) Ixx_R = Constant(1, 'Ixx_R', system) Iyy_R = Constant(1, 'Iyy_R', system) Izz_R = Constant(1, 'Izz_R', system) Ixx_A = Constant(1, 'Ixx_A', system) Iyy_A = Constant(1, 'Iyy_A', system) Izz_A = Constant(1, 'Izz_A', system) Ixx_B = Constant(1, 'Ixx_B', system) Iyy_B = Constant(1, 'Iyy_B', system) Izz_B = Constant(1, 'Izz_B', system) Ixx_C = Constant(1, 'Ixx_C', system) Iyy_C = Constant(1, 'Iyy_C', system) Izz_C = Constant(1, 'Izz_C', system) y, y_d, y_dd = Differentiable('y', system) qO, qO_d, qO_dd = Differentiable('qO', system) qR, qR_d, qR_dd = Differentiable('qR', system) qA, qA_d, qA_dd = Differentiable('qA', system) qB, qB_d, qB_dd = Differentiable('qB', system) qC, qC_d, qC_dd = Differentiable('qC', system) initialvalues = {} initialvalues[y] = ini_states[0] + tol_1 initialvalues[qO] = ini_states[1] + tol_1 initialvalues[qR] = ini_states[2] + tol_1 initialvalues[qA] = ini_states[3] + tol_1 initialvalues[qB] = ini_states[4] + tol_1 initialvalues[qC] = ini_states[5] + tol_1 initialvalues[y_d] = ini_states[6] + tol_1 initialvalues[qO_d] = ini_states[7] + tol_1 initialvalues[qR_d] = ini_states[8] + tol_1 initialvalues[qA_d] = ini_states[9] + tol_1 initialvalues[qB_d] = ini_states[10] + tol_1 initialvalues[qC_d] = ini_states[11] + tol_1 statevariables = system.get_state_variables() ini = [initialvalues[item] for item in statevariables] N = Frame('N') O = Frame('O') R = Frame('R') A = Frame('A') B = Frame('B') C = Frame('C') system.set_newtonian(N) if not global_q: O.rotate_fixed_axis_directed(N, [0, 0, 1], qO, system) R.rotate_fixed_axis_directed(O, [0, 0, 1], qR, system) A.rotate_fixed_axis_directed(R, [0, 0, 1], qA, system) B.rotate_fixed_axis_directed(A, [0, 0, 1], qB, system) C.rotate_fixed_axis_directed(B, [0, 0, 1], qC, system) else: O.rotate_fixed_axis_directed(N, [0, 0, 1], qO, system) R.rotate_fixed_axis_directed(N, [0, 0, 1], qR, system) A.rotate_fixed_axis_directed(N, [0, 0, 1], qA, system) B.rotate_fixed_axis_directed(N, [0, 0, 1], qB, system) C.rotate_fixed_axis_directed(N, [0, 0, 1], qC, system) pNO = 0 * N.x + y * N.y pOR = pNO + lO * N.x pRA = pOR + lR * R.x pAB = pRA + lA * A.x pBC = pAB + lB * B.x pCtip = pBC + lC * C.x pOcm = pNO + lO / 2 * N.x pRcm = pOR + lR / 2 * R.x pAcm = pRA + lA / 2 * A.x pBcm = pAB + lB / 2 * B.x pCcm = pBC + lC / 2 * C.x wNO = N.getw_(O) wOR = N.getw_(R) wRA = R.getw_(A) wAB = A.getw_(B) wBC = B.getw_(C) IO = Dyadic.build(O, Ixx_O, Iyy_O, Izz_O) IR = Dyadic.build(R, Ixx_R, Iyy_R, Izz_R) IA = Dyadic.build(A, Ixx_A, Iyy_A, Izz_A) IB = Dyadic.build(B, Ixx_B, Iyy_B, Izz_B) IC = Dyadic.build(C, Ixx_C, Iyy_C, Izz_C) BodyO = Body('BodyO', O, pOcm, mO, IO, system) BodyR = Body('BodyR', R, pRcm, mR, IR, system) BodyA = Body('BodyA', A, pAcm, mA, IA, system) BodyB = Body('BodyB', B, pBcm, mB, IB, system) BodyC = Body('BodyC', C, pCcm, mC, IC, system) j_tol = 3 * pi / 180 inv_k = 10 system.add_spring_force1(k + inv_k * (qA - qR + abs(qA - qR - j_tol)), (qA - qR - preload1) * N.z, wRA) system.add_spring_force1(k + inv_k * (qB - qA + abs(qB - qA - j_tol)), (qB - qA - preload2) * N.z, wAB) system.add_spring_force1(k + inv_k * (qC - qB + abs(qC - qB - j_tol)), (qC - qB - preload3) * N.z, wBC) vOcm = y_d * N.y vRcm = pRcm.time_derivative() vAcm = pAcm.time_derivative() vBcm = pBcm.time_derivative() vCcm = pCcm.time_derivative() nvRcm = 1 / (vRcm.length() + tol_1) * vRcm nvAcm = 1 / (vAcm.length() + tol_1) * vAcm nvBcm = 1 / (vBcm.length() + tol_1) * vBcm nvCcm = 1 / (vCcm.length() + tol_1) * vCcm vSoil = -direction * 1 * N.y nSoil = 1 / vSoil.length() * vSoil foperp = 8 * nSoil system.addforce(-foperp, vOcm) frperp = friction_arm_perp * nvRcm.dot(R.y) * R.y frpar = friction_arm_par * nvRcm.dot(R.x) * R.x system.addforce(-(frperp + frpar), vRcm) faperp = friction_perp * nvAcm.dot(A.y) * A.y fapar = friction_par * nvAcm.dot(A.x) * A.x system.addforce(-(faperp + fapar), vAcm) fbperp = friction_perp * nvBcm.dot(B.y) * B.y fbpar = friction_par * nvBcm.dot(B.x) * B.x system.addforce(-(fbperp + fbpar), vBcm) fcperp = friction_perp * nvCcm.dot(C.y) * C.y fcpar = friction_par * nvCcm.dot(C.x) * C.x system.addforce(-(fcperp + fcpar), vCcm) system.addforce(-b_damping * 1 * wRA, wRA) system.addforce(-b_damping * 1 * wAB, wAB) system.addforce(-b_damping * 1 * wBC, wBC) eq = [] eq_d = [(system.derivative(item)) for item in eq] eq_d.append(qR_d - omega1) eq_dd = [(system.derivative(item)) for item in eq_d] f, ma = system.getdynamics() func1 = system.state_space_post_invert(f, ma, eq_dd) points = [pNO, pOR, pRA, pAB, pBC, pCtip] constants = system.constant_values states = pynamics.integration.integrate_odeint(func1, ini, t, args=({ 'constants': constants }, )) final = numpy.asarray(states[-1, :]) logger1 = logging.getLogger('pynamics.system') logger2 = logging.getLogger('pynamics.integration') logger3 = logging.getLogger('pynamics.output') logger1.disabled = True logger2.disabled = True logger3.disabled = True points_output = PointsOutput(points, system, constant_values=constants) y1 = points_output.calc(states) if video_on == 1: plt.figure() plt.plot(*(y1[::int(len(y1) / 20)].T) * 1000) plt.axis('equal') plt.axis('equal') plt.title("Plate Configuration vs Distance") plt.xlabel("Configuration") plt.ylabel("Distance (mm)") plt.figure() plt.plot(t, numpy.rad2deg(states[:, 2])) plt.plot(t, numpy.rad2deg(states[:, 8])) plt.legend(["qR", "qR_d"]) plt.hlines(numpy.rad2deg(t1), tinitial, tfinal) plt.hlines(numpy.rad2deg(t2), tinitial, tfinal) plt.title("Robot Arm angle and velocitues (qR and qR_d) over Time") plt.xlabel("Time (s)") plt.ylabel("Angles,Velocities (deg, deg/s)") plt.figure() q_states = numpy.c_[(states[:, 2], states[:, 3], states[:, 4], states[:, 5])] plt.plot(t, numpy.rad2deg(q_states)) plt.title("Joint Angule over Time") plt.xlabel("Time (s)") plt.ylabel("Joint Angles (deg)") plt.legend(["Arm", "Joint 1", "Joint 2", "Joint 3"]) plt.figure() qd_states = numpy.c_[(states[:, 8], states[:, 9], states[:, 10], states[:, 11])] plt.plot(t, numpy.rad2deg(qd_states)) plt.legend(["qR_d", "qA_d", "qB_d", "qC_d"]) plt.title("Joint Angular Velocities over Time") plt.xlabel("Time (s)") plt.ylabel("Joint Angular Velocities (deg/s)") plt.legend(["Arm", "Joint 1", "Joint 2", "Joint 3"]) plt.figure() plt.plot(t, states[:, 0], '--') plt.plot(t, states[:, 6]) plt.title("Robot Distance and Velocity over time") plt.xlabel("Time (s)") plt.ylabel("Distance (mm)") plt.legend(["Distance", "Velocity of the robot"]) points_output.animate(fps=1 / tstep, movie_name=name1, lw=2, marker='o', color=(1, 0, 0, 1), linestyle='-') else: pass return final, states, y1
vBA = pBA.time_derivative(N,system) aBA = vBA.time_derivative(N,system) #constraint1 = pNA-pAN #constraint1_d = vectorderivative(constraint1,N) #constraint1_dd = vectorderivative(constraint1_d,N) # constraint2 = pAB-pBA constraint2_d = constraint2.time_derivative(N,system) constraint2_dd = constraint2_d.time_derivative(N,system) wNA = N.getw_(A) wAB = A.getw_(B) IA = Dyadic.build(A,Ixx_A,Iyy_A,Izz_A) IB = Dyadic.build(A,Ixx_B,Iyy_B,Izz_B) Body('BodyA',A,pAcm,mA,IA,system) Body('BodyB',B,pBcm,mB,IB,system) system.addforce(-b*wNA,wNA) system.addforce(-b*wAB,wAB) system.addforce(-k*qA*N.z,wNA) system.addforce(-k*qB*A.z,wAB) #system.addforce(fNAx*N.x+fNAy*N.y,vNA) #system.addforce(-fNAx*N.x+-fNAy*N.y,vAN) system.addforce(fABx*N.x+fABy*N.y,vBA)
plt.plot(*(item.T)) # for item,value in zip(system.get_state_variables(),result.x): # initialvalues[item]=value pAcm=pOA+lA/2*A.x pBcm=pAB+lB/2*B.x pCcm=pOC+lC/2*C.x pDcm=pCD+lD/2*D.x wOA = O.getw_(A) wAB = A.getw_(B) wOC = O.getw_(C) wCD = C.getw_(D) wBD = B.getw_(D) BodyO = Body('BodyO',O,pOcm,mO,Dyadic.build(O,I_main,I_main,I_main),system) #BodyA = Body('BodyA',A,pAcm,mA,Dyadic.build(A,I_leg,I_leg,I_leg),system) #BodyB = Body('BodyB',B,pBcm,mB,Dyadic.build(B,I_leg,I_leg,I_leg),system) #BodyC = Body('BodyC',C,pCcm,mC,Dyadic.build(C,I_leg,I_leg,I_leg),system) #BodyD = Body('BodyD',D,pDcm,mD,Dyadic.build(D,I_leg,I_leg,I_leg),system) ParticleA = Particle(pAcm,mA,'ParticleA') ParticleB = Particle(pBcm,mB,'ParticleB') ParticleC = Particle(pCcm,mC,'ParticleC') ParticleD = Particle(pDcm,mD,'ParticleD') system.addforce(-b*wOA,wOA) system.addforce(-b*wAB,wAB) system.addforce(-b*wOC,wOC) system.addforce(-b*wCD,wCD) system.addforce(-b*wBD,wBD)
wNA = N.getw_(A) wAB = A.getw_(B) wBC = B.getw_(C) # ### Vector derivatives # The time derivatives of vectors may also be # vCtip = pCtip.time_derivative(N,system) # ### Define Inertias and Bodies # The next several lines compute the inertia dyadics of each body and define a rigid body on each frame. In the case of frame C, we represent the mass as a particle located at point pCcm. # In[17]: IA = Dyadic.build(A, Ixx_A, Iyy_A, Izz_A) IB = Dyadic.build(B, Ixx_B, Iyy_B, Izz_B) IC = Dyadic.build(B, Ixx_C, Iyy_C, Izz_C) BodyA = Body('BodyA', A, pAcm, mA, IA, system) BodyB = Body('BodyB', B, pBcm, mB, IB, system) BodyC = Body('BodyC', C, pCcm, mC, IC, system) ParticleM = Particle(pm1, m1, 'ParticleM', system) # ## Forces and Torques # Forces and torques are added to the system with the generic ```addforce``` method. The first parameter supplied is a vector describing the force applied at a point or the torque applied along a given rotational axis. The second parameter is the vector describing the linear speed (for an applied force) or the angular velocity(for an applied torque) # In[18]: stretch1 = -pC1.dot(N.y) stretch1_s = (stretch1 + abs(stretch1))
initialvalues[qA_d] = 0 * pi / 180 N = Frame('N', system) A = Frame('A', system) system.set_newtonian(N) A.rotate_fixed_axis(N, [0, 0, 1], qA, system) pNA = 0 * N.x pAcm = pNA + lA / 2 * A.x pAtip = pNA + lA * A.x vAcm = pAcm.time_derivative(N, system) wNA = N.get_w_to(A) IA_motor = Dyadic.build(A, Ixx_motor, Iyy_motor, Izz_motor) IA_plate = Dyadic.build(A, Ixx_plate, Iyy_plate, Izz_plate) BodyMotor = Body('BodyMotor', A, pNA, mA, IA_motor) BodyPlate = Body('BodyPlate', A, pAcm, mA, IA_plate) f_aero_C2 = rho * vAcm.length() * (vAcm.dot(A.y)) * Area * A.y system.addforce(-f_aero_C2, vAcm) system.add_spring_force1(k, qA * N.z, wNA) tin = torque * sympy.sin(2 * sympy.pi * freq * system.t) system.addforce(tin * N.z, wNA) f, ma = system.getdynamics() changing_constants = [freq] static_constants = system.constant_values.copy()
N = Frame('N', system) A = Frame('A', system) system.set_newtonian(N) A.rotate_fixed_axis(N, [0, 0, 1], q, system) p1 = x * N.x p2 = p1 - l * A.y wNA = N.get_w_to(A) v1 = p1.time_derivative(N, system) v2 = p2.time_derivative(N, system) I = Dyadic.build(A, I_xx, I_yy, I_zz) BodyA = Body('BodyA', A, p2, m, I, system) ParticleO = Particle(p2, M, 'ParticleO', system) stretch = q - q0 system.add_spring_force1(k, (stretch) * N.z, wNA) system.addforce(-b * v2, v2) system.addforcegravity(-g * N.y) pos = sympy.cos(system.t * 2 * pi / 2) eq = pos * N.x - p1 eq_d = eq.time_derivative() eq_dd = eq_d.time_derivative() eq_dd_scalar = [] eq_dd_scalar.append(eq_dd.dot(N.x))
statevariables = [qA, qA_d] ini = [initialvalues[item] for item in statevariables] N = Frame('N') A = Frame('A') system.set_newtonian(N) A.rotate_fixed_axis_directed(N, [0, 0, 1], qA, system) pNA = 0 * N.x pAB = pNA + lA * A.x pAcm = pNA + lA / 2 * A.x wNA = N.getw_(A) BodyA = Body('BodyA', A, pAcm, mA, Dyadic.build(A, Ixx_A, Iyy_A, Izz_A), system) system.addforce(-b * wNA, wNA) system.addforce(-k * qA * N.z, wNA) system.addforcegravity(-g * N.y) t = scipy.arange(0, 10, .01) pynamics.tic() print('solving dynamics...') var_dd = system.solvedynamics('LU', False) pynamics.toc() print('integrating...') var_dd = var_dd.subs(system.constants) func1 = system.createsecondorderfunction(var_dd, statevariables,