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formatted mpc class with black

master
mcarfagno 2022-07-22 16:07:47 +01:00
parent 936dcd3642
commit 04609f8cf6
1 changed files with 79 additions and 55 deletions
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96
mpc_pybullet_demo/mpcpy/cvxpy_mpc.py
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@ -1,5 +1,6 @@
import numpy as np
np.seterr(divide='ignore', invalid='ignore')
np.seterr(divide="ignore", invalid="ignore")
from scipy.integrate import odeint
from scipy.interpolate import interp1d
@ -8,9 +9,11 @@ import cvxpy as opt
from .utils import *
from .mpc_config import Params
P=Params()
def get_linear_model_matrices(x_bar,u_bar):
P = Params()
def get_linear_model_matrices(x_bar, u_bar):
"""
Computes the LTI approximated state space model x' = Ax + Bu + C
"""
@ -28,36 +31,51 @@ def get_linear_model_matrices(x_bar,u_bar):
cd = np.cos(delta)
td = np.tan(delta)
A = np.zeros((P.N,P.N))
A[0,2] = ct
A[0,3] = -v*st
A[1,2] = st
A[1,3] = v*ct
A[3,2] = v*td/P.L
A_lin = np.eye(P.N)+P.DT*A
A = np.zeros((P.N, P.N))
A[0, 2] = ct
A[0, 3] = -v * st
A[1, 2] = st
A[1, 3] = v * ct
A[3, 2] = v * td / P.L
A_lin = np.eye(P.N) + P.DT * A
B = np.zeros((P.N,P.M))
B[2,0]=1
B[3,1]=v/(P.L*cd**2)
B_lin=P.DT*B
B = np.zeros((P.N, P.M))
B[2, 0] = 1
B[3, 1] = v / (P.L * cd**2)
B_lin = P.DT * B
f_xu=np.array([v*ct, v*st, a, v*td/P.L]).reshape(P.N,1)
C_lin = P.DT*(f_xu - np.dot(A, x_bar.reshape(P.N,1)) - np.dot(B, u_bar.reshape(P.M,1))).flatten()
f_xu = np.array([v * ct, v * st, a, v * td / P.L]).reshape(P.N, 1)
C_lin = (
P.DT
* (
f_xu - np.dot(A, x_bar.reshape(P.N, 1)) - np.dot(B, u_bar.reshape(P.M, 1))
).flatten()
)
#return np.round(A_lin,6), np.round(B_lin,6), np.round(C_lin,6)
# return np.round(A_lin,6), np.round(B_lin,6), np.round(C_lin,6)
return A_lin, B_lin, C_lin
class MPC():
class MPC:
def __init__(self, N, M, Q, R):
"""
"""
""" """
self.state_len = N
self.action_len = M
self.state_cost = Q
self.action_cost = R
def optimize_linearized_model(self, A, B, C, initial_state, target, time_horizon=10, Q=None, R=None, verbose=False):
def optimize_linearized_model(
self,
A,
B,
C,
initial_state,
target,
time_horizon=10,
Q=None,
R=None,
verbose=False,
):
"""
Optimisation problem defined for the linearised model,
:param A:
@ -74,40 +92,46 @@ class MPC():
assert len(initial_state) == self.state_len
if (Q == None or R==None):
if Q == None or R == None:
Q = self.state_cost
R = self.action_cost
# Create variables
x = opt.Variable((self.state_len, time_horizon + 1), name='states')
u = opt.Variable((self.action_len, time_horizon), name='actions')
x = opt.Variable((self.state_len, time_horizon + 1), name="states")
u = opt.Variable((self.action_len, time_horizon), name="actions")
# Loop through the entire time_horizon and append costs
cost_function = []
for t in range(time_horizon):
_cost = opt.quad_form(target[:, t + 1] - x[:, t + 1], Q) +\
opt.quad_form(u[:, t], R)
_cost = opt.quad_form(target[:, t + 1] - x[:, t + 1], Q) + opt.quad_form(
u[:, t], R
)
_constraints = [x[:, t + 1] == A @ x[:, t] + B @ u[:, t] + C,
u[0, t] >= -P.MAX_ACC, u[0, t] <= P.MAX_ACC,
u[1, t] >= -P.MAX_STEER, u[1, t] <= P.MAX_STEER]
#opt.norm(target[:, t + 1] - x[:, t + 1], 1) <= 0.1]
_constraints = [
x[:, t + 1] == A @ x[:, t] + B @ u[:, t] + C,
u[0, t] >= -P.MAX_ACC,
u[0, t] <= P.MAX_ACC,
u[1, t] >= -P.MAX_STEER,
u[1, t] <= P.MAX_STEER,
]
# opt.norm(target[:, t + 1] - x[:, t + 1], 1) <= 0.1]
# Actuation rate of change
if t < (time_horizon - 1):
_cost += opt.quad_form(u[:,t + 1] - u[:,t], R * 1)
_constraints += [opt.abs(u[0, t + 1] - u[0, t])/P.DT <= P.MAX_D_ACC]
_constraints += [opt.abs(u[1, t + 1] - u[1, t])/P.DT <= P.MAX_D_STEER]
_cost += opt.quad_form(u[:, t + 1] - u[:, t], R * 1)
_constraints += [opt.abs(u[0, t + 1] - u[0, t]) / P.DT <= P.MAX_D_ACC]
_constraints += [opt.abs(u[1, t + 1] - u[1, t]) / P.DT <= P.MAX_D_STEER]
if t == 0:
#_constraints += [opt.norm(target[:, time_horizon] - x[:, time_horizon], 1) <= 0.01,
# _constraints += [opt.norm(target[:, time_horizon] - x[:, time_horizon], 1) <= 0.01,
# x[:, 0] == initial_state]
_constraints += [x[:, 0] == initial_state]
cost_function.append(opt.Problem(opt.Minimize(_cost), constraints=_constraints))
cost_function.append(
opt.Problem(opt.Minimize(_cost), constraints=_constraints)
)
# Add final cost
problem = sum(cost_function)