complete simulator

nmpc/cgmres/main_cgmres.py

@@ -0,0 +1,113 @@
+import numpy as np
+import matplotlib.pyplot as plt
+import math
+
+class SampleSystem():
+    """SampleSystem
+
+    Attributes
+    -----------
+    
+    """
+    def __init__(self, init_x_1=0., init_x_2=0.):
+        """
+        Parameters
+        -----------
+        
+        """
+        self.x_1 = init_x_1
+        self.x_2 = init_x_2
+        self.history_x_1 = [init_x_1]
+        self.history_x_2 = [init_x_2]
+
+    def update_state(self, u, dt=0.01):
+        """
+        Parameters
+        ------------
+        u : float
+            input of system in some cases this means the reference
+        dt : float in seconds, optional
+            sampling time of simulation, default is 0.01 [s]
+        """
+        # for theta 1, theta 1 dot, theta 2, theta 2 dot
+        k0 = [0.0 for _ in range(2)]
+        k1 = [0.0 for _ in range(2)]
+        k2 = [0.0 for _ in range(2)]
+        k3 = [0.0 for _ in range(2)]
+
+        functions = [self._func_x_1, self._func_x_2]
+
+        # solve Runge-Kutta
+        for i, func in enumerate(functions):
+            k0[i] = dt * func(self.x_1, self.x_2, u)
+        
+        for i, func in enumerate(functions):
+            k1[i] = dt * func(self.x_1 + k0[0]/2., self.x_2 + k0[1]/2., u)
+        
+        for i, func in enumerate(functions):
+            k2[i] = dt * func(self.x_1 + k1[0]/2., self.x_2 + k1[1]/2., u)
+        
+        for i, func in enumerate(functions):
+            k3[i] =  dt * func(self.x_1 + k2[0], self.x_2 + k2[1], u)
+        
+        self.x_1 += (k0[0] + 2. * k1[0] + 2. * k2[0] + k3[0]) / 6.
+        self.x_2 += (k0[1] + 2. * k1[1] + 2. * k2[1] + k3[1]) / 6.
+    
+        # save
+        self.history_x_1.append(self.x_1)
+        self.history_x_2.append(self.x_2)
+
+    def _func_x_1(self, y_1, y_2, u):
+        """
+        Parameters
+        ------------
+        
+        """
+        y_dot = y_2
+
+        return y_dot
+    
+    def _func_x_2(self, y_1, y_2, u):
+        """
+        Parameters
+        ------------
+        
+        """
+        y_dot = (1 - y_1**2 - y_2**2) * y_2 - y_1 + u
+
+        return y_dot
+
+
+def main():
+    # simulation time
+    dt = 0.01
+    iteration_time = 20.
+    iteration_num = int(iteration_time/dt)
+
+    # plant
+    plant_system = SampleSystem(init_x_1=2., init_x_2=0.)
+
+    # controller
+
+    for i in range(iteration_num):
+        u = 1.0
+        plant_system.update_state(u)
+    
+    # figure
+    fig = plt.figure()
+
+    x_1_fig = fig.add_subplot(231)
+    x_2_fig = fig.add_subplot(232)
+    u_fig = fig.add_subplot(233)
+
+    x_1_fig.plot(np.arange(iteration_num+1)*dt, plant_system.history_x_1)
+    x_2_fig.plot(np.arange(iteration_num+1)*dt, plant_system.history_x_2)
+
+    plt.show()
+
+
+if __name__ == "__main__":
+    main()
+
+
+