Question

我想使用odeint解决此3-3微分方程组，但出现此错误：

Traceback (most recent call last):
  File "/home/spyros/Documents/Spyros/Diplwmatiki/ROS/Serial connection/Dynamic_problem.py", line 81, in <module>
    u = odeint(subsystem2,u0,t)
  File "/usr/local/lib/python2.7/dist-packages/scipy/integrate/odepack.py", line 233, in odeint
    int(bool(tfirst)))
RuntimeError: The array return by func must be one-dimensional, but got ndim=2.

我阅读了以下类似主题： How to solve a system of differential equations using scipy.odeint error with odeint (RuntimeError: The array return by func must be one-dimensional, but got ndim=2.) Scipy optimize error 但是我没有找到解决方案的方法。返回数组的维数= 2的可能性如何。我在函数的输入中有3个变量，在返回数组中有3个微分方程和相同的方程。我该如何解决这个错误？预先谢谢你。

import numpy as np 
from scipy.integrate import odeint 
import matplotlib.pyplot as plt

added_mass_x = 0.03 # kg 
added_mass_y = 0.04 
mb = 0.3 # kg 
m1 = mb-added_mass_x 
m2 = mb-added_mass_y 
l1 = 0.07 # m 
l2 = 0.05 # m 
J = 0.00050797 # kgm^2 
Sa = 0.0110 # m^2 
Cd = 2.44 
Cl = 3.41 
Kd = 0.000655 # kgm^2 
r = 1000 # kg/m^3

c1 = 0.5*r*Sa*Cd 
c2 = 0.5*r*Sa*Cl 
c3 = 0.5*mb*(l1**2) 
c4 = Kd/J 
c5 = (1/(2*J))*(l1**2)*mb*l2 
c6 = (1/(3*J))*(l1**3)*mb

theta_0 = 10*(np.pi/180) # rad 
theta_A = 20*(np.pi/180) # rad 
f = 2 # Hz

t = np.linspace(0,100,8000) # s 
omega = 2*np.pi*f # rad/s 
theta = theta_0 + theta_A*np.sin(omega*t) # rad 
theta_deg = (theta*180)/np.pi # deg 
thetadotdot = -(omega**2)*theta_A*np.sin(omega*t) # rad/s^2

def subsystem2(u,t):
    vcx = u[0]
    vcy = u[1]
    wz = u[2]

    vcxdot = (m2/m1)*vcy*wz-(c1/m1)*vcx*np.sqrt((vcx**2)+(vcy**2))+(c2/m1)*vcy*np.sqrt((vcx**2)+(vcy**2))*np.arctan2(vcy,vcx)-(c3/m1)*thetadotdot*np.sin(theta)
    vcydot = -(m1/m2)*vcx*wz-(c1/m2)*vcy*np.sqrt((vcx**2)+(vcy**2))-(c2/m2)*vcx*np.sqrt((vcx**2)+(vcy**2))*np.arctan2(vcy,vcx)+(c3/m2)*thetadotdot*np.cos(theta)
    wzdot = ((m1-m2)/J)*vcx*vcy-c4*wz*wz*np.sign(wz)-c5*thetadotdot*np.cos(theta)-c6*thetadotdot

    return [vcxdot,vcydot,wzdot]

# arxikes synthikes 
vcx_0 = 0 
vcy_0 = 0 
wz_0 = 0 
u0 = [vcx_0,vcy_0,wz_0]

# epilysi systimatos diaforikwn 
u = odeint(subsystem2,u0,t,tfirst=False)

vcx = u[:,0] 
vcy = u[:,1] 
wz = u[:,2]

Answer 1

我设法通过在vcxdot之前将四个方程（omega，theta，theta_deg和thedotdot）移入管道来解决这个问题。我不知道到底是什么问题，但是在此之后它可以正常工作。

“ RuntimeError：由func返回的数组必须是一维的，但得到ndim = 2。”

1 个答案: