Problème de subplots avec matplotlib

 import matplotlib.pyplot as plt
 from scipy.integrate import odeint
 import numpy as np
 from math import sin,cos
 from matplotlib.widgets import Slider, Button


#### DEFINITION DES CONSTANTES DU PROBLEME ####

#Masse du drone (kg)
m=0.486

#Coefficients de trainée de translation (N/m/s)
K_ft_x,K_ft_y,K_ft_z=5.5670*10**(-3),5.5670*10**(-3),6.3540*10**(-4)

#Coefficients de frottements aérodynamiques (N/m/s)+    
K_fa_x,K_fa_y,K_fa_z=5.5670*10**(-3),5.5670*10**(-3),6.3540*10**(-4)

#Inertie (kg.m²)
Ix,Iy,Iz=3.8278*10**(-3),3.8288*10**(-3),7.6566*10**(-3)

#Inertie des rotors (kg.m²)
Jr=2.8385*10**(-5)

#Coefficent de drag (N.m/rad/s)
d= 3.2320*10**(-7)

#Coefficients de portance (N/rad/s)
b=2.984*10**(-5)

#Distance rotor-centre de gravité (m)
l=0.25

#Constante de gravitation (m/s²)
g=9.806

a1,b1,c1,d1,a2,b2,c2,d2,a3,b3,c3=-K_fa_x/Ix,(Iy-Iz)/Ix,l*b/Ix,-Jr/Ix,-K_fa_y/Iy,(Iz-Ix)/Iy,l*b/Iy,-Jr/Iy,-K_fa_z/Iz,(Ix-Iy)/Iz,d/Iz

#Temps,pas
T,h=10,0.01

#### CONDITIONS INTIALES ####


v_th_0,v_ph_0,v_ps_0=0,0,0

W=[0,0,0,0]

v_x_0,v_y_0,v_z_0 = 0,0,0

A=[pi/4,pi/4]

#### DEFINITION DU SYSTEME DIFFERENTIEL ####


def v_theta(vth,vph,vps,W):
    return(a1*vth**2+b1*vth*vps+c1*(W[3]**2-W[1]**2)+d1*vph*(W[0]-W[1]+W[2]-W[3]))

def v_phi(vth,vph,vps,W):
    return(a2*vph**2+b2*vth*vps+c2*(W[2]**2-W[0]**2)+d2*vth*(W[0]-W[1]+W[2]-W[3]))
    
def v_psi(vth,vph,vps,W):
    return(a3*vps**2+b3*vth*vph+c3*(W[0]**2-W[1]**2+W[2]**2-W[3]**2))
    
def v_x(x,t,W,A):
    return(b/m*sin(A[1])*(W[0]+W[1]+W[2]+W[3])-K_ft_x/m*x**2)

def v_y(y,t,W,A):
    return(b/m*sin(A[0])*cos(A[1])*(W[0]+W[1]+W[2]+W[3])-K_ft_y/m*y**2)

def v_z(z,t,W,A):
    return(b/m*cos(A[0])*cos(A[1])*(W[0]+W[1]+W[2]+W[3])-K_ft_z/m*z**2-g)

def F(X,t):    
    return(v_theta(X[0],X[1],X[2],W),v_phi(X[0],X[1],X[2],W),v_psi(X[0],X[1],X[2],W))


## RESOLUTION DES EQUATIONS DIFFERENTIELLES ANGULAIRES AVEC ODEINT ## 

    
TPS = np.linspace(0,T,1000)

solution = odeint(F,[v_th_0,v_ph_0,v_ps_0],TPS)

TH=solution[:,0]
PH=solution[:,1]
PS=solution[:,2]


V_X=odeint(v_x,v_x_0,TPS,(W,A))
V_Y=odeint(v_y,v_y_0,TPS,(W,A))
V_Z=odeint(v_z,v_z_0,TPS,(W,A))


## TRACE DES SOLUTIONS ##


fig, (ax1,ax2) = plt.subplots(nrows = 1, ncols = 2)

ax1.set_ymargin(25)

p1, = ax1.plot(TPS,TH)
p2, = ax1.plot(TPS,PH)
p3, = ax1.plot(TPS,PS)

p4, = ax2.plot(TPS,V_X)
p5, = ax2.plot(TPS,V_Y)
p6, = ax2.plot(TPS,V_Z)

plt.subplots_adjust(bottom = 0.25, right = 0.89, left = 0.16 , wspace = 0.31, top = 0.96)


## REGLAGE DES MOTEURS  ##


axe_slider1 = plt.axes([0.15, 0.151, 0.25, 0.03])
axe_slider2 = plt.axes([0.15, 0.100, 0.25, 0.03])
axe_slider3 = plt.axes([0.15, 0.051, 0.25, 0.03])
axe_slider4 = plt.axes([0.15, 0.001, 0.25, 0.03])

axe_slider5 = plt.axes([0.60,0.151,0.25,0.03])
axe_slider6 = plt.axes([0.60,0.051,0.25,0.03])

moteurs1 = Slider(axe_slider1, 'Vitesse de rotation moteur 1',0,100,0)
moteurs2 = Slider(axe_slider2, 'Vitesse de rotation moteur 2',0,100,0)
moteurs3 = Slider(axe_slider3, 'Vitesse de rotation moteur 3',0,100,0)
moteurs4 = Slider(axe_slider4, 'Vitesse de rotation moteur 4',0,100,0)

angle_theta = Slider(axe_slider5, 'Angle theta', -pi/2, pi/2,0)
angle_phi = Slider(axe_slider6, 'Angle phi', -pi/2, pi/2,0)


def val_update(val) : 

    val1 = moteurs1.val
    val2 = moteurs2.val
    val3 = moteurs3.val
    val4 = moteurs4.val
    
    W[0]=val1
    W[2]=val2
    W[1]=val3
    W[3]=val4
    
    nouvelle_solution = odeint(F,[v_th_0,v_ph_0,v_ps_0],TPS)
    
    TH = nouvelle_solution[:,0]
    PH = nouvelle_solution[:,1]
    PS = nouvelle_solution[:,2]
    
    p1.set_ydata(TH)
    p2.set_ydata(PH)
    p3.set_ydata(PS)
    
    val5 = angle_theta.val
    val6 = angle_phi.val
    
    V_X = odeint(v_x,v_x_0,TPS,(W,[val5,val6]))
    V_Y = odeint(v_y,v_y_0,TPS,(W,[val5,val6]))
    V_Z = odeint(v_z,v_z_0,TPS,(W,[val5,val6]))
    
    p4.set_ydata(V_X)
    p5.set_ydata(V_Y)
    p6.set_ydata(V_Z)
    
    fig.canvas.draw_idle()
    
angle_theta.on_changed(val_update)
angle_phi.on_changed(val_update)

moteurs1.on_changed(val_update)
moteurs2.on_changed(val_update)
moteurs3.on_changed(val_update)
moteurs4.on_changed(val_update)



##  AFFICHAGE DE LA SOLUTION ##


plt.show()