296 lines
7.3 KiB
Python
296 lines
7.3 KiB
Python
import numpy as np
|
|
import matplotlib.pyplot as plt
|
|
|
|
from cvxpy_mpc.utils import compute_path_from_wp, get_ref_trajectory
|
|
from cvxpy_mpc import MPC, VehicleModel
|
|
|
|
import sys
|
|
import time
|
|
import pathlib
|
|
import pybullet as p
|
|
import time
|
|
|
|
# Params
|
|
TARGET_VEL = 1.0 # m/s
|
|
L = 0.3 # vehicle wheelbase [m]
|
|
T = 5 # Prediction Horizon [s]
|
|
DT = 0.2 # discretization step [s]
|
|
|
|
|
|
def get_state(robotId):
|
|
"""
|
|
|
|
Args:
|
|
robotId ():
|
|
|
|
Returns:
|
|
|
|
"""
|
|
robPos, robOrn = p.getBasePositionAndOrientation(robotId)
|
|
linVel, angVel = p.getBaseVelocity(robotId)
|
|
|
|
return np.array(
|
|
[
|
|
robPos[0],
|
|
robPos[1],
|
|
np.sqrt(linVel[0] ** 2 + linVel[1] ** 2),
|
|
p.getEulerFromQuaternion(robOrn)[2],
|
|
]
|
|
)
|
|
|
|
|
|
def set_ctrl(robotId, currVel, acceleration, steeringAngle):
|
|
"""
|
|
|
|
Args:
|
|
robotId ():
|
|
currVel ():
|
|
acceleration ():
|
|
steeringAngle ():
|
|
"""
|
|
gearRatio = 1.0 / 21
|
|
steering = [0, 2]
|
|
wheels = [8, 15]
|
|
maxForce = 50
|
|
|
|
targetVelocity = currVel + acceleration * DT
|
|
|
|
for wheel in wheels:
|
|
p.setJointMotorControl2(
|
|
robotId,
|
|
wheel,
|
|
p.VELOCITY_CONTROL,
|
|
targetVelocity=targetVelocity / gearRatio,
|
|
force=maxForce,
|
|
)
|
|
|
|
for steer in steering:
|
|
p.setJointMotorControl2(
|
|
robotId, steer, p.POSITION_CONTROL, targetPosition=steeringAngle
|
|
)
|
|
|
|
|
|
def plot_results(path, x_history, y_history):
|
|
plt.style.use("ggplot")
|
|
plt.figure()
|
|
plt.title("MPC Tracking Results")
|
|
|
|
plt.plot(
|
|
path[0, :], path[1, :], c="tab:orange", marker=".", label="reference track"
|
|
)
|
|
plt.plot(
|
|
x_history,
|
|
y_history,
|
|
c="tab:blue",
|
|
marker=".",
|
|
alpha=0.5,
|
|
label="vehicle trajectory",
|
|
)
|
|
plt.axis("equal")
|
|
plt.legend()
|
|
plt.show()
|
|
|
|
|
|
def run_sim():
|
|
p.connect(p.GUI)
|
|
p.resetDebugVisualizerCamera(
|
|
cameraDistance=1.0,
|
|
cameraYaw=-90,
|
|
cameraPitch=-45,
|
|
cameraTargetPosition=[-0.1, -0.0, 0.65],
|
|
)
|
|
|
|
p.resetSimulation()
|
|
|
|
p.setGravity(0, 0, -10)
|
|
useRealTimeSim = 1
|
|
|
|
p.setTimeStep(1.0 / 120.0)
|
|
p.setRealTimeSimulation(useRealTimeSim) # either this
|
|
|
|
file_path = pathlib.Path(__file__).parent.resolve()
|
|
plane = p.loadURDF(str(file_path) + "/racecar/plane.urdf")
|
|
car = p.loadURDF(
|
|
str(file_path) + "/racecar/f10_racecar/racecar_differential.urdf", [0, 0.3, 0.3]
|
|
)
|
|
|
|
for wheel in range(p.getNumJoints(car)):
|
|
# print("joint[",wheel,"]=", p.getJointInfo(car,wheel))
|
|
p.setJointMotorControl2(
|
|
car, wheel, p.VELOCITY_CONTROL, targetVelocity=0, force=0
|
|
)
|
|
p.getJointInfo(car, wheel)
|
|
|
|
c = p.createConstraint(
|
|
car,
|
|
9,
|
|
car,
|
|
11,
|
|
jointType=p.JOINT_GEAR,
|
|
jointAxis=[0, 1, 0],
|
|
parentFramePosition=[0, 0, 0],
|
|
childFramePosition=[0, 0, 0],
|
|
)
|
|
p.changeConstraint(c, gearRatio=1, maxForce=10000)
|
|
|
|
c = p.createConstraint(
|
|
car,
|
|
10,
|
|
car,
|
|
13,
|
|
jointType=p.JOINT_GEAR,
|
|
jointAxis=[0, 1, 0],
|
|
parentFramePosition=[0, 0, 0],
|
|
childFramePosition=[0, 0, 0],
|
|
)
|
|
p.changeConstraint(c, gearRatio=-1, maxForce=10000)
|
|
|
|
c = p.createConstraint(
|
|
car,
|
|
9,
|
|
car,
|
|
13,
|
|
jointType=p.JOINT_GEAR,
|
|
jointAxis=[0, 1, 0],
|
|
parentFramePosition=[0, 0, 0],
|
|
childFramePosition=[0, 0, 0],
|
|
)
|
|
p.changeConstraint(c, gearRatio=-1, maxForce=10000)
|
|
|
|
c = p.createConstraint(
|
|
car,
|
|
16,
|
|
car,
|
|
18,
|
|
jointType=p.JOINT_GEAR,
|
|
jointAxis=[0, 1, 0],
|
|
parentFramePosition=[0, 0, 0],
|
|
childFramePosition=[0, 0, 0],
|
|
)
|
|
p.changeConstraint(c, gearRatio=1, maxForce=10000)
|
|
|
|
c = p.createConstraint(
|
|
car,
|
|
16,
|
|
car,
|
|
19,
|
|
jointType=p.JOINT_GEAR,
|
|
jointAxis=[0, 1, 0],
|
|
parentFramePosition=[0, 0, 0],
|
|
childFramePosition=[0, 0, 0],
|
|
)
|
|
p.changeConstraint(c, gearRatio=-1, maxForce=10000)
|
|
|
|
c = p.createConstraint(
|
|
car,
|
|
17,
|
|
car,
|
|
19,
|
|
jointType=p.JOINT_GEAR,
|
|
jointAxis=[0, 1, 0],
|
|
parentFramePosition=[0, 0, 0],
|
|
childFramePosition=[0, 0, 0],
|
|
)
|
|
p.changeConstraint(c, gearRatio=-1, maxForce=10000)
|
|
|
|
c = p.createConstraint(
|
|
car,
|
|
1,
|
|
car,
|
|
18,
|
|
jointType=p.JOINT_GEAR,
|
|
jointAxis=[0, 1, 0],
|
|
parentFramePosition=[0, 0, 0],
|
|
childFramePosition=[0, 0, 0],
|
|
)
|
|
p.changeConstraint(c, gearRatio=-1, gearAuxLink=15, maxForce=10000)
|
|
c = p.createConstraint(
|
|
car,
|
|
3,
|
|
car,
|
|
19,
|
|
jointType=p.JOINT_GEAR,
|
|
jointAxis=[0, 1, 0],
|
|
parentFramePosition=[0, 0, 0],
|
|
childFramePosition=[0, 0, 0],
|
|
)
|
|
p.changeConstraint(c, gearRatio=-1, gearAuxLink=15, maxForce=10000)
|
|
|
|
# Interpolated Path to follow given waypoints
|
|
path = compute_path_from_wp(
|
|
[0, 3, 4, 6, 10, 11, 12, 6, 1, 0],
|
|
[0, 0, 2, 4, 3, 3, -1, -6, -2, -2],
|
|
0.05,
|
|
)
|
|
|
|
for x_, y_ in zip(path[0, :], path[1, :]):
|
|
p.addUserDebugLine([x_, y_, 0], [x_, y_, 0.33], [0, 0, 1])
|
|
|
|
# starting conditions
|
|
control = np.zeros(2)
|
|
|
|
# Cost Matrices
|
|
Q = [20, 20, 10, 20] # state error cost [x,y,v,yaw]
|
|
Qf = [30, 30, 30, 30] # state error cost at final timestep [x,y,v,yaw]
|
|
R = [10, 10] # input cost [acc ,steer]
|
|
P = [10, 10] # input rate of change cost [acc ,steer]
|
|
|
|
mpc = MPC(VehicleModel(), T, DT, Q, Qf, R, P)
|
|
x_history = []
|
|
y_history = []
|
|
|
|
input("\033[92m Press Enter to continue... \033[0m")
|
|
|
|
while 1:
|
|
state = get_state(car)
|
|
x_history.append(state[0])
|
|
y_history.append(state[1])
|
|
|
|
# track path in bullet
|
|
p.addUserDebugLine(
|
|
[state[0], state[1], 0], [state[0], state[1], 0.5], [1, 0, 0]
|
|
)
|
|
|
|
if np.sqrt((state[0] - path[0, -1]) ** 2 + (state[1] - path[1, -1]) ** 2) < 0.2:
|
|
print("Success! Goal Reached")
|
|
set_ctrl(car, 0, 0, 0)
|
|
plot_results(path, x_history, y_history)
|
|
input("Press Enter to continue...")
|
|
p.disconnect()
|
|
return
|
|
|
|
# Get Reference_traj
|
|
# NOTE: inputs are in world frame
|
|
target = get_ref_trajectory(state, path, TARGET_VEL, T, DT)
|
|
|
|
# for MPC base link frame is used:
|
|
# so x, y, yaw are 0.0, but speed is the same
|
|
ego_state = np.array([0.0, 0.0, state[2], 0.0])
|
|
|
|
# to account for MPC latency
|
|
# simulate one timestep actuation delay
|
|
ego_state[0] = ego_state[0] + ego_state[2] * np.cos(ego_state[3]) * DT
|
|
ego_state[1] = ego_state[1] + ego_state[2] * np.sin(ego_state[3]) * DT
|
|
ego_state[2] = ego_state[2] + control[0] * DT
|
|
ego_state[3] = ego_state[3] + control[0] * np.tan(control[1]) / L * DT
|
|
|
|
# optimization loop
|
|
start = time.time()
|
|
|
|
# MPC step
|
|
_, u_mpc = mpc.step(ego_state, target, control, verbose=False)
|
|
control[0] = u_mpc.value[0, 0]
|
|
control[1] = u_mpc.value[1, 0]
|
|
|
|
elapsed = time.time() - start
|
|
print("CVXPY Optimization Time: {:.4f}s".format(elapsed))
|
|
|
|
set_ctrl(car, state[2], control[0], control[1])
|
|
|
|
if DT - elapsed > 0:
|
|
time.sleep(DT - elapsed)
|
|
|
|
|
|
if __name__ == "__main__":
|
|
run_sim()
|