diff --git a/SLAM/FastSLAM1/animation.gif b/SLAM/FastSLAM1/animation.gif new file mode 100644 index 00000000..f4dbc721 Binary files /dev/null and b/SLAM/FastSLAM1/animation.gif differ diff --git a/SLAM/FastSLAM1/fast_slam1.py b/SLAM/FastSLAM1/fast_slam1.py index 04d4913c..e76f5f6b 100644 --- a/SLAM/FastSLAM1/fast_slam1.py +++ b/SLAM/FastSLAM1/fast_slam1.py @@ -1,6 +1,6 @@ """ -Fast SLAM example +FastSLAM 1.0 example author: Atsushi Sakai (@Atsushi_twi) @@ -11,13 +11,14 @@ import math import matplotlib.pyplot as plt -# EKF state covariance -Q = np.diag([1.0, math.radians(4.0)])**2 -R = np.diag([0.5, math.radians(15.0)])**2 +# Fast SLAM covariance +Q = np.diag([3.0, math.radians(10.0)])**2 +R = np.diag([1.0, math.radians(20.0)])**2 # Simulation parameter Qsim = np.diag([0.3, math.radians(2.0)])**2 Rsim = np.diag([0.5, math.radians(10.0)])**2 +OFFSET_YAWRATE_NOISE = 0.01 DT = 0.1 # time tick [s] SIM_TIME = 50.0 # simulation time [s] @@ -26,7 +27,7 @@ M_DIST_TH = 2.0 # Threshold of Mahalanobis distance for data association. STATE_SIZE = 3 # State size [x,y,yaw] LM_SIZE = 2 # LM srate size [x,y] N_PARTICLE = 100 # number of particle -NTH = N_PARTICLE / 2.0 # Number of particle for re-sampling +NTH = N_PARTICLE / 1.5 # Number of particle for re-sampling show_animation = True @@ -38,11 +39,13 @@ class Particle: self.x = 0.0 self.y = 0.0 self.yaw = 0.0 - self.lm = np.matrix(np.zeros((N_LM, 2))) - self.lmP = np.matrix(np.zeros((N_LM * 2, 2))) + # landmark x-y positions + self.lm = np.matrix(np.zeros((N_LM, LM_SIZE))) + # landmark position covariance + self.lmP = np.matrix(np.zeros((N_LM * LM_SIZE, LM_SIZE))) -def fast_slam(particles, PEst, u, z): +def fast_slam(particles, u, z): particles = predict_particles(particles, u) @@ -50,9 +53,7 @@ def fast_slam(particles, PEst, u, z): particles = resampling(particles) - xEst = calc_final_state(particles) - - return xEst, PEst, particles + return particles def normalize_weight(particles): @@ -193,6 +194,7 @@ def compute_weight(particle, z, Q): try: invS = np.linalg.inv(S) except np.linalg.linalg.LinAlgError: + print("singuler") return 1.0 num = math.exp(-0.5 * dx.T * invS * dx) @@ -216,7 +218,7 @@ def update_with_observation(particles, z): # known landmark else: w = compute_weight(particles[ip], z[iz, :], Q) - particles[ip].w = particles[ip].w * w + particles[ip].w *= w particles[ip] = update_landmark(particles[ip], z[iz, :], Q) return particles @@ -239,7 +241,6 @@ def resampling(particles): # print(Neff) if Neff < NTH: # resampling - # print("resampling") wcum = np.cumsum(pw) base = np.cumsum(pw * 0.0 + 1 / N_PARTICLE) - 1 / N_PARTICLE resampleid = base + np.random.rand(base.shape[1]) / N_PARTICLE @@ -263,10 +264,17 @@ def resampling(particles): return particles -def calc_input(): - v = 1.0 # [m/s] - yawrate = 0.1 # [rad/s] +def calc_input(time): + + if time <= 3.0: + v = 0.0 + yawrate = 0.0 + else: + v = 1.0 # [m/s] + yawrate = 0.1 # [rad/s] + u = np.matrix([v, yawrate]).T + return u @@ -291,7 +299,7 @@ def observation(xTrue, xd, u, RFID): # add noise to input ud1 = u[0, 0] + np.random.randn() * Rsim[0, 0] - ud2 = u[1, 0] + np.random.randn() * Rsim[1, 1] + 0.01 + ud2 = u[1, 0] + np.random.randn() * Rsim[1, 1] + OFFSET_YAWRATE_NOISE ud = np.matrix([ud1, ud2]).T xd = motion_model(xd, ud) @@ -334,16 +342,18 @@ def main(): # RFID positions [x, y] RFID = np.array([[10.0, -2.0], [15.0, 10.0], + [15.0, 15.0], + [10.0, 20.0], [3.0, 15.0], [-5.0, 20.0], - [-5.0, 5.0] + [-5.0, 5.0], + [-10.0, 15.0] ]) N_LM = RFID.shape[0] # State Vector [x y yaw v]' xEst = np.matrix(np.zeros((STATE_SIZE, 1))) xTrue = np.matrix(np.zeros((STATE_SIZE, 1))) - PEst = np.eye(STATE_SIZE) xDR = np.matrix(np.zeros((STATE_SIZE, 1))) # Dead reckoning @@ -356,11 +366,13 @@ def main(): while SIM_TIME >= time: time += DT - u = calc_input() + u = calc_input(time) xTrue, z, xDR, ud = observation(xTrue, xDR, u, RFID) - xEst, PEst, particles = fast_slam(particles, PEst, ud, z) + particles = fast_slam(particles, ud, z) + + xEst = calc_final_state(particles) x_state = xEst[0: STATE_SIZE]