106 lines
2.6 KiB
Python
106 lines
2.6 KiB
Python
import numpy as np
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import matplotlib.pyplot as plt
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from matplotlib import animation
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from utils import compute_path_from_wp
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from cvxpy_mpc import optimize
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import sys
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import time
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import pybullet as p
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import time
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def get_state(robotId):
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"""
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"""
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robPos, robOrn = p.getBasePositionAndOrientation(robotId)
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linVel,angVel = p.getBaseVelocity(robotId)
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return[robPos[0], robPos[1], p.getEulerFromQuaternion(robOrn)[2]]
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def set_ctrl(robotId,v,w):
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"""
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"""
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L= 0.354
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R= 0.076/2
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rightWheelVelocity= (2*v+w*L)/(2*R)
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leftWheelVelocity = (2*v-w*L)/(2*R)
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p.setJointMotorControl2(robotId,0,p.VELOCITY_CONTROL,targetVelocity=leftWheelVelocity,force=1000)
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p.setJointMotorControl2(robotId,1,p.VELOCITY_CONTROL,targetVelocity=rightWheelVelocity,force=1000)
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def plot(path,x_history,y_history):
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"""
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"""
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plt.style.use("ggplot")
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plt.figure()
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plt.title("MPC Tracking Results")
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plt.plot(path[0,:],path[1,:], c='tab:orange',marker=".",label="reference track")
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plt.plot(x_history, y_history, c='tab:blue',marker=".",alpha=0.5,label="vehicle trajectory")
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plt.legend()
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plt.show()
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def run_sim():
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"""
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"""
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p.connect(p.GUI)
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start_offset = [0,2,0]
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start_orientation = p.getQuaternionFromEuler([0,0,0])
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turtle = p.loadURDF("turtlebot.urdf",start_offset, start_orientation)
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plane = p.loadURDF("plane.urdf")
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p.setRealTimeSimulation(1)
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p.setGravity(0,0,-10)
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# MPC time step
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dt = 0.25
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# starting guess output
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N = 5 #number of state variables
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M = 2 #number of control variables
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T = 20 #Prediction Horizon
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opt_u = np.zeros((M,T))
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opt_u[0,:] = 1 #m/s
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opt_u[1,:] = np.radians(0) #rad/s
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# Interpolated Path to follow given waypoints
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path = compute_path_from_wp([0,10,12,2,4,14],[0,0,2,10,12,12])
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x_history=[]
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y_history=[]
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while (1):
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state = get_state(turtle)
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x_history.append(state[0])
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y_history.append(state[1])
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#track path in bullet
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p.addUserDebugLine([state[0],state[1],0],[state[0],state[1],0.5],[1,0,0])
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if np.sqrt((state[0]-path[0,-1])**2+(state[1]-path[1,-1])**2)<1:
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print("Success! Goal Reached")
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set_ctrl(turtle,0,0)
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plot(path,x_history,y_history)
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p.disconnect()
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return
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#optimization loop
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start=time.time()
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opt_u = optimize(state,opt_u,path)
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elapsed=time.time()-start
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print("CVXPY Optimization Time: {:.4f}s".format(elapsed))
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set_ctrl(turtle,opt_u[0,1],opt_u[1,1])
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if dt-elapsed>0:
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time.sleep(dt-elapsed)
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if __name__ == '__main__':
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run_sim()
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