99 lines
2.6 KiB
Python
Executable File
99 lines
2.6 KiB
Python
Executable File
import numpy as np
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from scipy.interpolate import interp1d
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def compute_path_from_wp(start_xp, start_yp, step = 0.1):
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"""
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"""
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final_xp=[]
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final_yp=[]
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delta = step #[m]
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for idx in range(len(start_xp)-1):
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section_len = np.sqrt(np.sum(np.power(np.diff(start_xp[idx:idx+2]),2)+np.power(np.diff(start_yp[idx:idx+2]),2)))
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interp_range = np.linspace(0,1, int(1+section_len/delta))
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fx=interp1d(np.linspace(0,1,2),start_xp[idx:idx+2],kind=1)
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fy=interp1d(np.linspace(0,1,2),start_yp[idx:idx+2],kind=1)
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final_xp=np.append(final_xp,fx(interp_range))
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final_yp=np.append(final_yp,fy(interp_range))
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return np.vstack((final_xp,final_yp))
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def get_nn_idx(state,path):
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"""
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"""
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dx = state[0]-path[0,:]
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dy = state[1]-path[1,:]
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dist = np.sqrt(dx**2 + dy**2)
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nn_idx = np.argmin(dist)
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try:
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v = [path[0,nn_idx+1] - path[0,nn_idx],
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path[1,nn_idx+1] - path[1,nn_idx]]
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v /= np.linalg.norm(v)
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d = [path[0,nn_idx] - state[0],
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path[1,nn_idx] - state[1]]
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if np.dot(d,v) > 0:
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target_idx = nn_idx
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else:
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target_idx = nn_idx+1
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except IndexError as e:
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target_idx = nn_idx
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return target_idx
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def road_curve(state,track):
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"""
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"""
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POLY_RANK = 3
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#given vehicle pos find lookahead waypoints
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nn_idx=get_nn_idx(state,track)
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LOOKAHED = POLY_RANK*2
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lk_wp=track[:,max(0,nn_idx-1):nn_idx+LOOKAHED]
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#trasform lookahead waypoints to vehicle ref frame
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dx = lk_wp[0,:] - state[0]
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dy = lk_wp[1,:] - state[1]
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wp_vehicle_frame = np.vstack(( dx * np.cos(-state[3]) - dy * np.sin(-state[3]),
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dy * np.cos(-state[3]) + dx * np.sin(-state[3]) ))
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#fit poly
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return np.polyfit(wp_vehicle_frame[0,:], wp_vehicle_frame[1,:], POLY_RANK, rcond=None, full=False, w=None, cov=False)
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# def f(x,coeff):
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# """
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# """
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# return round(coeff[0]*x**3 + coeff[1]*x**2 + coeff[2]*x**1 + coeff[3]*x**0,6)
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# def f(x,coeff):
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# return round(coeff[0]*x**5+coeff[1]*x**4+coeff[2]*x**3+coeff[3]*x**2+coeff[4]*x**1+coeff[5]*x**0,6)
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def f(x,coeff):
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y=0
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j=len(coeff)
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for k in range(j):
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y += coeff[k]*x**(j-k-1)
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return round(y,6)
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# def df(x,coeff):
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# """
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# """
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# return round(3*coeff[0]*x**2 + 2*coeff[1]*x**1 + coeff[2]*x**0,6)
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# def df(x,coeff):
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# return round(5*coeff[0]*x**4 + 4*coeff[1]*x**3 +3*coeff[2]*x**2 + 2*coeff[3]*x**1 + coeff[4]*x**0,6)
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def df(x,coeff):
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y=0
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j=len(coeff)
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for k in range(j-1):
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y += (j-k-1)*coeff[k]*x**(j-k-2)
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return round(y,6)
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