diff --git a/.github/workflows/greetings.yml b/.github/workflows/greetings.yml
deleted file mode 100644
index 3da4a694..00000000
--- a/.github/workflows/greetings.yml
+++ /dev/null
@@ -1,13 +0,0 @@
-name: Greetings
-
-on: [pull_request, issues]
-
-jobs:
-  greeting:
-    runs-on: ubuntu-latest
-    steps:
-    - uses: actions/first-interaction@v1
-      with:
-        repo-token: ${{ secrets.GITHUB_TOKEN }}
-        issue-message: 'Message that will be displayed on users'' This is first issue for you on this project'
-        pr-message: 'Message that will be displayed on users'' This is first pr for you on this project'
diff --git a/AerialNavigation/drone_3d_trajectory_following/Quadrotor.py b/AerialNavigation/drone_3d_trajectory_following/Quadrotor.py
index 9b38677c..413a8625 100644
--- a/AerialNavigation/drone_3d_trajectory_following/Quadrotor.py
+++ b/AerialNavigation/drone_3d_trajectory_following/Quadrotor.py
@@ -8,7 +8,6 @@ from math import cos, sin
 import numpy as np
 import matplotlib.pyplot as plt
 
-
 class Quadrotor():
     def __init__(self, x=0, y=0, z=0, roll=0, pitch=0, yaw=0, size=0.25, show_animation=True):
         self.p1 = np.array([size / 2, 0, 0, 1]).T
@@ -24,6 +23,10 @@ class Quadrotor():
         if self.show_animation:
             plt.ion()
             fig = plt.figure()
+            # for stopping simulation with the esc key.
+            fig.canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
+
             self.ax = fig.add_subplot(111, projection='3d')
 
         self.update_pose(x, y, z, roll, pitch, yaw)
@@ -81,4 +84,4 @@ class Quadrotor():
         plt.ylim(-5, 5)
         self.ax.set_zlim(0, 10)
 
-        plt.pause(0.001)
\ No newline at end of file
+        plt.pause(0.001)
diff --git a/AerialNavigation/rocket_powered_landing/rocket_powered_landing.py b/AerialNavigation/rocket_powered_landing/rocket_powered_landing.py
index dde76f19..eb9d7ba4 100644
--- a/AerialNavigation/rocket_powered_landing/rocket_powered_landing.py
+++ b/AerialNavigation/rocket_powered_landing/rocket_powered_landing.py
@@ -567,6 +567,9 @@ def plot_animation(X, U):  # pragma: no cover
 
     fig = plt.figure()
     ax = fig.gca(projection='3d')
+    # for stopping simulation with the esc key.
+    fig.canvas.mpl_connect('key_release_event',
+            lambda event: [exit(0) if event.key == 'escape' else None])
 
     for k in range(K):
         plt.cla()
diff --git a/ArmNavigation/arm_obstacle_navigation/arm_obstacle_navigation.py b/ArmNavigation/arm_obstacle_navigation/arm_obstacle_navigation.py
index 2bcc33d0..f3bd2557 100644
--- a/ArmNavigation/arm_obstacle_navigation/arm_obstacle_navigation.py
+++ b/ArmNavigation/arm_obstacle_navigation/arm_obstacle_navigation.py
@@ -162,6 +162,9 @@ def astar_torus(grid, start_node, goal_node):
         for i in range(1, len(route)):
             grid[route[i]] = 6
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.imshow(grid, cmap=cmap, norm=norm, interpolation=None)
             plt.show()
             plt.pause(1e-2)
@@ -262,4 +265,4 @@ class NLinkArm(object):
 
 
 if __name__ == '__main__':
-    main()
\ No newline at end of file
+    main()
diff --git a/ArmNavigation/arm_obstacle_navigation/arm_obstacle_navigation_2.py b/ArmNavigation/arm_obstacle_navigation/arm_obstacle_navigation_2.py
index b8c1ce89..429cd4d2 100644
--- a/ArmNavigation/arm_obstacle_navigation/arm_obstacle_navigation_2.py
+++ b/ArmNavigation/arm_obstacle_navigation/arm_obstacle_navigation_2.py
@@ -193,6 +193,9 @@ def astar_torus(grid, start_node, goal_node):
         for i in range(1, len(route)):
             grid[route[i]] = 6
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.imshow(grid, cmap=cmap, norm=norm, interpolation=None)
             plt.show()
             plt.pause(1e-2)
diff --git a/ArmNavigation/n_joint_arm_to_point_control/NLinkArm.py b/ArmNavigation/n_joint_arm_to_point_control/NLinkArm.py
index 8ed12c56..854ade90 100644
--- a/ArmNavigation/n_joint_arm_to_point_control/NLinkArm.py
+++ b/ArmNavigation/n_joint_arm_to_point_control/NLinkArm.py
@@ -51,6 +51,9 @@ class NLinkArm(object):
 
     def plot(self):  # pragma: no cover
         plt.cla()
+        # for stopping simulation with the esc key.
+        plt.gcf().canvas.mpl_connect('key_release_event',
+                lambda event: [exit(0) if event.key == 'escape' else None])
 
         for i in range(self.n_links + 1):
             if i is not self.n_links:
diff --git a/ArmNavigation/two_joint_arm_to_point_control/two_joint_arm_to_point_control.py b/ArmNavigation/two_joint_arm_to_point_control/two_joint_arm_to_point_control.py
index 0e91be0f..75e7cf30 100644
--- a/ArmNavigation/two_joint_arm_to_point_control/two_joint_arm_to_point_control.py
+++ b/ArmNavigation/two_joint_arm_to_point_control/two_joint_arm_to_point_control.py
@@ -114,6 +114,9 @@ def animation():
 def main():  # pragma: no cover
     fig = plt.figure()
     fig.canvas.mpl_connect("button_press_event", click)
+    # for stopping simulation with the esc key.
+    fig.canvas.mpl_connect('key_release_event',
+            lambda event: [exit(0) if event.key == 'escape' else None])
     two_joint_arm()
 
 
diff --git a/Bipedal/bipedal_planner/bipedal_planner.py b/Bipedal/bipedal_planner/bipedal_planner.py
index 3cf2936e..6502ce5b 100644
--- a/Bipedal/bipedal_planner/bipedal_planner.py
+++ b/Bipedal/bipedal_planner/bipedal_planner.py
@@ -111,6 +111,9 @@ class BipedalPlanner(object):
                     if c > len(com_trajectory_for_plot):
                         # set up plotter
                         plt.cla()
+                        # for stopping simulation with the esc key.
+                        plt.gcf().canvas.mpl_connect('key_release_event',
+                                lambda event: [exit(0) if event.key == 'escape' else None])
                         ax.set_zlim(0, z_c * 2)
                         ax.set_aspect('equal', 'datalim')
 
diff --git a/Localization/ensemble_kalman_filter/ensemble_kalman_filter.py b/Localization/ensemble_kalman_filter/ensemble_kalman_filter.py
index 3e2af749..58a998e2 100644
--- a/Localization/ensemble_kalman_filter/ensemble_kalman_filter.py
+++ b/Localization/ensemble_kalman_filter/ensemble_kalman_filter.py
@@ -213,6 +213,9 @@ def main():
 
         if show_animation:
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
 
             for i in range(len(z[:, 0])):
                 plt.plot([xTrue[0, 0], z[i, 2]], [xTrue[1, 0], z[i, 3]], "-k")
diff --git a/Localization/extended_kalman_filter/extended_kalman_filter.py b/Localization/extended_kalman_filter/extended_kalman_filter.py
index d2d7178a..2b057e21 100644
--- a/Localization/extended_kalman_filter/extended_kalman_filter.py
+++ b/Localization/extended_kalman_filter/extended_kalman_filter.py
@@ -191,6 +191,9 @@ def main():
 
         if show_animation:
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.plot(hz[0, :], hz[1, :], ".g")
             plt.plot(hxTrue[0, :].flatten(),
                      hxTrue[1, :].flatten(), "-b")
diff --git a/Localization/histogram_filter/histogram_filter.py b/Localization/histogram_filter/histogram_filter.py
index db715a6d..135b476c 100644
--- a/Localization/histogram_filter/histogram_filter.py
+++ b/Localization/histogram_filter/histogram_filter.py
@@ -233,6 +233,9 @@ def main():
 
         if show_animation:
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             draw_heat_map(grid_map.data, mx, my)
             plt.plot(xTrue[0, :], xTrue[1, :], "xr")
             plt.plot(RF_ID[:, 0], RF_ID[:, 1], ".k")
diff --git a/Localization/particle_filter/particle_filter.py b/Localization/particle_filter/particle_filter.py
index d14b7c06..bfef3ed9 100644
--- a/Localization/particle_filter/particle_filter.py
+++ b/Localization/particle_filter/particle_filter.py
@@ -230,6 +230,9 @@ def main():
 
         if show_animation:
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
 
             for i in range(len(z[:, 0])):
                 plt.plot([xTrue[0, 0], z[i, 1]], [xTrue[1, 0], z[i, 2]], "-k")
diff --git a/Localization/unscented_kalman_filter/unscented_kalman_filter.py b/Localization/unscented_kalman_filter/unscented_kalman_filter.py
index 45d5b781..7bf279ce 100644
--- a/Localization/unscented_kalman_filter/unscented_kalman_filter.py
+++ b/Localization/unscented_kalman_filter/unscented_kalman_filter.py
@@ -240,6 +240,9 @@ def main():
 
         if show_animation:
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.plot(hz[0, :], hz[1, :], ".g")
             plt.plot(np.array(hxTrue[0, :]).flatten(),
                      np.array(hxTrue[1, :]).flatten(), "-b")
diff --git a/Mapping/circle_fitting/circle_fitting.py b/Mapping/circle_fitting/circle_fitting.py
index dae9413d..c331d567 100644
--- a/Mapping/circle_fitting/circle_fitting.py
+++ b/Mapping/circle_fitting/circle_fitting.py
@@ -124,6 +124,9 @@ def main():
 
         if show_animation:  # pragma: no cover
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.axis("equal")
             plt.plot(0.0, 0.0, "*r")
             plot_circle(cx, cy, cr)
diff --git a/Mapping/gaussian_grid_map/gaussian_grid_map.py b/Mapping/gaussian_grid_map/gaussian_grid_map.py
index 9c1aa273..b7664f1a 100644
--- a/Mapping/gaussian_grid_map/gaussian_grid_map.py
+++ b/Mapping/gaussian_grid_map/gaussian_grid_map.py
@@ -73,6 +73,9 @@ def main():
 
         if show_animation:  # pragma: no cover
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             draw_heatmap(gmap, minx, maxx, miny, maxy, xyreso)
             plt.plot(ox, oy, "xr")
             plt.plot(0.0, 0.0, "ob")
diff --git a/Mapping/kmeans_clustering/kmeans_clustering.py b/Mapping/kmeans_clustering/kmeans_clustering.py
index c2518b80..e18960e9 100644
--- a/Mapping/kmeans_clustering/kmeans_clustering.py
+++ b/Mapping/kmeans_clustering/kmeans_clustering.py
@@ -133,8 +133,10 @@ def main():
         # for animation
         if show_animation:  # pragma: no cover
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             clusters.plot_cluster()
-
             plt.plot(cx, cy, "or")
             plt.xlim(-2.0, 10.0)
             plt.ylim(-2.0, 10.0)
diff --git a/Mapping/raycasting_grid_map/raycasting_grid_map.py b/Mapping/raycasting_grid_map/raycasting_grid_map.py
index a0d90609..8ce37b92 100644
--- a/Mapping/raycasting_grid_map/raycasting_grid_map.py
+++ b/Mapping/raycasting_grid_map/raycasting_grid_map.py
@@ -124,6 +124,9 @@ def main():
 
         if show_animation:  # pragma: no cover
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             draw_heatmap(pmap, minx, maxx, miny, maxy, xyreso)
             plt.plot(ox, oy, "xr")
             plt.plot(0.0, 0.0, "ob")
diff --git a/Mapping/rectangle_fitting/rectangle_fitting.py b/Mapping/rectangle_fitting/rectangle_fitting.py
index 2018f025..1a2a5340 100644
--- a/Mapping/rectangle_fitting/rectangle_fitting.py
+++ b/Mapping/rectangle_fitting/rectangle_fitting.py
@@ -242,6 +242,9 @@ def main():
 
         if show_animation:  # pragma: no cover
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.axis("equal")
             plt.plot(0.0, 0.0, "*r")
             v1.plot()
diff --git a/PathPlanning/AStar/a_star.py b/PathPlanning/AStar/a_star.py
index 061aafbe..b0c718c9 100644
--- a/PathPlanning/AStar/a_star.py
+++ b/PathPlanning/AStar/a_star.py
@@ -79,6 +79,9 @@ class AStarPlanner:
             if show_animation:  # pragma: no cover
                 plt.plot(self.calc_grid_position(current.x, self.minx),
                          self.calc_grid_position(current.y, self.miny), "xc")
+                # for stopping simulation with the esc key.
+                plt.gcf().canvas.mpl_connect('key_release_event',
+                        lambda event: [exit(0) if event.key == 'escape' else None])
                 if len(closed_set.keys()) % 10 == 0:
                     plt.pause(0.001)
 
diff --git a/PathPlanning/BatchInformedRRTStar/batch_informed_rrtstar.py b/PathPlanning/BatchInformedRRTStar/batch_informed_rrtstar.py
index 8e7af39f..227b3f9d 100644
--- a/PathPlanning/BatchInformedRRTStar/batch_informed_rrtstar.py
+++ b/PathPlanning/BatchInformedRRTStar/batch_informed_rrtstar.py
@@ -534,6 +534,9 @@ class BITStar(object):
     def draw_graph(self, xCenter=None, cBest=None, cMin=None, etheta=None,
                    samples=None, start=None, end=None):
         plt.clf()
+        # for stopping simulation with the esc key.
+        plt.gcf().canvas.mpl_connect('key_release_event',
+                lambda event: [exit(0) if event.key == 'escape' else None])
         for rnd in samples:
             if rnd is not None:
                 plt.plot(rnd[0], rnd[1], "^k")
diff --git a/PathPlanning/ClosedLoopRRTStar/pure_pursuit.py b/PathPlanning/ClosedLoopRRTStar/pure_pursuit.py
index be1d2238..a413a05d 100644
--- a/PathPlanning/ClosedLoopRRTStar/pure_pursuit.py
+++ b/PathPlanning/ClosedLoopRRTStar/pure_pursuit.py
@@ -135,6 +135,9 @@ def closed_loop_prediction(cx, cy, cyaw, speed_profile, goal):
 
         if target_ind % 1 == 0 and animation:  # pragma: no cover
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.plot(cx, cy, "-r", label="course")
             plt.plot(x, y, "ob", label="trajectory")
             plt.plot(cx[target_ind], cy[target_ind], "xg", label="target")
diff --git a/PathPlanning/Dijkstra/dijkstra.py b/PathPlanning/Dijkstra/dijkstra.py
index 5c06f53a..62da6d76 100644
--- a/PathPlanning/Dijkstra/dijkstra.py
+++ b/PathPlanning/Dijkstra/dijkstra.py
@@ -69,6 +69,9 @@ class Dijkstra:
             if show_animation:  # pragma: no cover
                 plt.plot(self.calc_position(current.x, self.minx),
                          self.calc_position(current.y, self.miny), "xc")
+                # for stopping simulation with the esc key.
+                plt.gcf().canvas.mpl_connect('key_release_event',
+                        lambda event: [exit(0) if event.key == 'escape' else None])
                 if len(closedset.keys()) % 10 == 0:
                     plt.pause(0.001)
 
diff --git a/PathPlanning/DubinsPath/dubins_path_planning.py b/PathPlanning/DubinsPath/dubins_path_planning.py
index 96c9c8e4..410e8db0 100644
--- a/PathPlanning/DubinsPath/dubins_path_planning.py
+++ b/PathPlanning/DubinsPath/dubins_path_planning.py
@@ -318,6 +318,9 @@ def test():
 
         if show_animation:
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.plot(px, py, label="final course " + str(mode))
 
             #  plotting
diff --git a/PathPlanning/DynamicWindowApproach/dynamic_window_approach.py b/PathPlanning/DynamicWindowApproach/dynamic_window_approach.py
index 2dab2f30..92fd08bb 100644
--- a/PathPlanning/DynamicWindowApproach/dynamic_window_approach.py
+++ b/PathPlanning/DynamicWindowApproach/dynamic_window_approach.py
@@ -268,6 +268,9 @@ def main(gx=10.0, gy=10.0, robot_type=RobotType.circle):
 
         if show_animation:
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.plot(predicted_trajectory[:, 0], predicted_trajectory[:, 1], "-g")
             plt.plot(x[0], x[1], "xr")
             plt.plot(goal[0], goal[1], "xb")
diff --git a/PathPlanning/Eta3SplinePath/eta3_spline_path.py b/PathPlanning/Eta3SplinePath/eta3_spline_path.py
index 072b0bb4..414f6b45 100644
--- a/PathPlanning/Eta3SplinePath/eta3_spline_path.py
+++ b/PathPlanning/Eta3SplinePath/eta3_spline_path.py
@@ -213,6 +213,9 @@ def test1():
         if show_animation:
             # plot the path
             plt.plot(pos[0, :], pos[1, :])
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.pause(1.0)
 
     if show_animation:
diff --git a/PathPlanning/FrenetOptimalTrajectory/frenet_optimal_trajectory.py b/PathPlanning/FrenetOptimalTrajectory/frenet_optimal_trajectory.py
index f3ae2a43..1b62ea01 100644
--- a/PathPlanning/FrenetOptimalTrajectory/frenet_optimal_trajectory.py
+++ b/PathPlanning/FrenetOptimalTrajectory/frenet_optimal_trajectory.py
@@ -49,13 +49,6 @@ class quintic_polynomial:
     def __init__(self, xs, vxs, axs, xe, vxe, axe, T):
 
         # calc coefficient of quintic polynomial
-        self.xs = xs
-        self.vxs = vxs
-        self.axs = axs
-        self.xe = xe
-        self.vxe = vxe
-        self.axe = axe
-
         self.a0 = xs
         self.a1 = vxs
         self.a2 = axs / 2.0
@@ -99,12 +92,7 @@ class quartic_polynomial:
 
     def __init__(self, xs, vxs, axs, vxe, axe, T):
 
-        # calc coefficient of quintic polynomial
-        self.xs = xs
-        self.vxs = vxs
-        self.axs = axs
-        self.vxe = vxe
-        self.axe = axe
+        # calc coefficient of quartic polynomial
 
         self.a0 = xs
         self.a1 = vxs
@@ -184,7 +172,7 @@ def calc_frenet_paths(c_speed, c_d, c_d_d, c_d_dd, s0):
             fp.d_dd = [lat_qp.calc_second_derivative(t) for t in fp.t]
             fp.d_ddd = [lat_qp.calc_third_derivative(t) for t in fp.t]
 
-            # Loongitudinal motion planning (Velocity keeping)
+            # Longitudinal motion planning (Velocity keeping)
             for tv in np.arange(TARGET_SPEED - D_T_S * N_S_SAMPLE, TARGET_SPEED + D_T_S * N_S_SAMPLE, D_T_S):
                 tfp = copy.deepcopy(fp)
                 lon_qp = quartic_polynomial(s0, c_speed, 0.0, tv, 0.0, Ti)
@@ -347,6 +335,9 @@ def main():
 
         if show_animation:  # pragma: no cover
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.plot(tx, ty)
             plt.plot(ob[:, 0], ob[:, 1], "xk")
             plt.plot(path.x[1:], path.y[1:], "-or")
diff --git a/PathPlanning/GridBasedSweepCPP/grid_based_sweep_coverage_path_planner.py b/PathPlanning/GridBasedSweepCPP/grid_based_sweep_coverage_path_planner.py
index 9d7e1616..0d2239a9 100644
--- a/PathPlanning/GridBasedSweepCPP/grid_based_sweep_coverage_path_planner.py
+++ b/PathPlanning/GridBasedSweepCPP/grid_based_sweep_coverage_path_planner.py
@@ -213,6 +213,9 @@ def sweep_path_search(sweep_searcher, gmap, grid_search_animation=False):
 
     if grid_search_animation:
         fig, ax = plt.subplots()
+        # for stopping simulation with the esc key.
+        fig.canvas.mpl_connect('key_release_event',
+                lambda event: [exit(0) if event.key == 'escape' else None])
 
     while True:
         cxind, cyind = sweep_searcher.move_target_grid(cxind, cyind, gmap)
@@ -266,6 +269,9 @@ def planning_animation(ox, oy, reso):  # pragma: no cover
     if do_animation:
         for ipx, ipy in zip(px, py):
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.plot(ox, oy, "-xb")
             plt.plot(px, py, "-r")
             plt.plot(ipx, ipy, "or")
diff --git a/PathPlanning/HybridAStar/a_star.py b/PathPlanning/HybridAStar/a_star.py
index c1c82edd..a2729328 100644
--- a/PathPlanning/HybridAStar/a_star.py
+++ b/PathPlanning/HybridAStar/a_star.py
@@ -78,6 +78,9 @@ def dp_planning(sx, sy, gx, gy, ox, oy, reso, rr):
         # show graph
         if show_animation:  # pragma: no cover
             plt.plot(current.x * reso, current.y * reso, "xc")
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             if len(closedset.keys()) % 10 == 0:
                 plt.pause(0.001)
 
@@ -228,4 +231,4 @@ def main():
 
 if __name__ == '__main__':
     show_animation = True
-    main()
\ No newline at end of file
+    main()
diff --git a/PathPlanning/HybridAStar/hybrid_a_star.py b/PathPlanning/HybridAStar/hybrid_a_star.py
index ea6a4661..725976dc 100644
--- a/PathPlanning/HybridAStar/hybrid_a_star.py
+++ b/PathPlanning/HybridAStar/hybrid_a_star.py
@@ -327,6 +327,9 @@ def hybrid_a_star_planning(start, goal, ox, oy, xyreso, yawreso):
 
         if show_animation:  # pragma: no cover
             plt.plot(current.xlist[-1], current.ylist[-1], "xc")
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             if len(closedList.keys()) % 10 == 0:
                 plt.pause(0.001)
 
diff --git a/PathPlanning/InformedRRTStar/informed_rrt_star.py b/PathPlanning/InformedRRTStar/informed_rrt_star.py
index 065868f2..912e56fa 100644
--- a/PathPlanning/InformedRRTStar/informed_rrt_star.py
+++ b/PathPlanning/InformedRRTStar/informed_rrt_star.py
@@ -266,8 +266,10 @@ class InformedRRTStar:
         return path
 
     def draw_graph(self, xCenter=None, cBest=None, cMin=None, etheta=None, rnd=None):
-
         plt.clf()
+        # for stopping simulation with the esc key.
+        plt.gcf().canvas.mpl_connect('key_release_event',
+                lambda event: [exit(0) if event.key == 'escape' else None])
         if rnd is not None:
             plt.plot(rnd[0], rnd[1], "^k")
             if cBest != float('inf'):
diff --git a/PathPlanning/LQRPlanner/LQRplanner.py b/PathPlanning/LQRPlanner/LQRplanner.py
index 5a0b453f..ba01526a 100644
--- a/PathPlanning/LQRPlanner/LQRplanner.py
+++ b/PathPlanning/LQRPlanner/LQRplanner.py
@@ -54,6 +54,9 @@ class LQRPlanner:
 
             # animation
             if show_animation:  # pragma: no cover
+                # for stopping simulation with the esc key.
+                plt.gcf().canvas.mpl_connect('key_release_event',
+                        lambda event: [exit(0) if event.key == 'escape' else None])
                 plt.plot(sx, sy, "or")
                 plt.plot(gx, gy, "ob")
                 plt.plot(rx, ry, "-r")
diff --git a/PathPlanning/LQRRRTStar/lqr_rrt_star.py b/PathPlanning/LQRRRTStar/lqr_rrt_star.py
index 2e276b9f..177131ac 100644
--- a/PathPlanning/LQRRRTStar/lqr_rrt_star.py
+++ b/PathPlanning/LQRRRTStar/lqr_rrt_star.py
@@ -102,6 +102,9 @@ class LQRRRTStar(RRTStar):
 
     def draw_graph(self, rnd=None):
         plt.clf()
+        # for stopping simulation with the esc key.
+        plt.gcf().canvas.mpl_connect('key_release_event',
+                lambda event: [exit(0) if event.key == 'escape' else None])
         if rnd is not None:
             plt.plot(rnd.x, rnd.y, "^k")
         for node in self.node_list:
diff --git a/PathPlanning/PotentialFieldPlanning/potential_field_planning.py b/PathPlanning/PotentialFieldPlanning/potential_field_planning.py
index 1e918fb1..31904fa4 100644
--- a/PathPlanning/PotentialFieldPlanning/potential_field_planning.py
+++ b/PathPlanning/PotentialFieldPlanning/potential_field_planning.py
@@ -98,6 +98,9 @@ def potential_field_planning(sx, sy, gx, gy, ox, oy, reso, rr):
 
     if show_animation:
         draw_heatmap(pmap)
+        # for stopping simulation with the esc key.
+        plt.gcf().canvas.mpl_connect('key_release_event',
+                lambda event: [exit(0) if event.key == 'escape' else None])
         plt.plot(ix, iy, "*k")
         plt.plot(gix, giy, "*m")
 
diff --git a/PathPlanning/ProbabilisticRoadMap/probabilistic_road_map.py b/PathPlanning/ProbabilisticRoadMap/probabilistic_road_map.py
index 8090e336..7715174e 100644
--- a/PathPlanning/ProbabilisticRoadMap/probabilistic_road_map.py
+++ b/PathPlanning/ProbabilisticRoadMap/probabilistic_road_map.py
@@ -194,6 +194,9 @@ def dijkstra_planning(sx, sy, gx, gy, ox, oy, rr, road_map, sample_x, sample_y):
 
         # show graph
         if show_animation and len(closedset.keys()) % 2 == 0:
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.plot(current.x, current.y, "xg")
             plt.pause(0.001)
 
diff --git a/PathPlanning/QuinticPolynomialsPlanner/quintic_polynomials_planner.py b/PathPlanning/QuinticPolynomialsPlanner/quintic_polynomials_planner.py
index ecef7d45..e7c744d1 100644
--- a/PathPlanning/QuinticPolynomialsPlanner/quintic_polynomials_planner.py
+++ b/PathPlanning/QuinticPolynomialsPlanner/quintic_polynomials_planner.py
@@ -26,14 +26,7 @@ class QuinticPolynomial:
 
     def __init__(self, xs, vxs, axs, xe, vxe, axe, T):
 
-        # calc coefficient of quinic polynomial
-        self.xs = xs
-        self.vxs = vxs
-        self.axs = axs
-        self.xe = xe
-        self.vxe = vxe
-        self.axe = axe
-
+        # calc coefficient of quintic polynomial
         self.a0 = xs
         self.a1 = vxs
         self.a2 = axs / 2.0
@@ -151,6 +144,9 @@ def quintic_polynomials_planner(sx, sy, syaw, sv, sa, gx, gy, gyaw, gv, ga, max_
     if show_animation:  # pragma: no cover
         for i, _ in enumerate(time):
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.grid(True)
             plt.axis("equal")
             plot_arrow(sx, sy, syaw)
diff --git a/PathPlanning/RRT/rrt.py b/PathPlanning/RRT/rrt.py
index 5b6f3252..b590d7b1 100644
--- a/PathPlanning/RRT/rrt.py
+++ b/PathPlanning/RRT/rrt.py
@@ -138,6 +138,9 @@ class RRT:
 
     def draw_graph(self, rnd=None):
         plt.clf()
+        # for stopping simulation with the esc key.
+        plt.gcf().canvas.mpl_connect('key_release_event',
+                lambda event: [exit(0) if event.key == 'escape' else None])
         if rnd is not None:
             plt.plot(rnd.x, rnd.y, "^k")
         for node in self.node_list:
diff --git a/PathPlanning/RRTDubins/rrt_dubins.py b/PathPlanning/RRTDubins/rrt_dubins.py
index 339acd2c..4599904c 100644
--- a/PathPlanning/RRTDubins/rrt_dubins.py
+++ b/PathPlanning/RRTDubins/rrt_dubins.py
@@ -106,6 +106,9 @@ class RRTDubins(RRT):
 
     def draw_graph(self, rnd=None):  # pragma: no cover
         plt.clf()
+        # for stopping simulation with the esc key.
+        plt.gcf().canvas.mpl_connect('key_release_event',
+                lambda event: [exit(0) if event.key == 'escape' else None])
         if rnd is not None:
             plt.plot(rnd.x, rnd.y, "^k")
         for node in self.node_list:
diff --git a/PathPlanning/RRTStarDubins/rrt_star_dubins.py b/PathPlanning/RRTStarDubins/rrt_star_dubins.py
index 4d731293..65fac54c 100644
--- a/PathPlanning/RRTStarDubins/rrt_star_dubins.py
+++ b/PathPlanning/RRTStarDubins/rrt_star_dubins.py
@@ -112,6 +112,9 @@ class RRTStarDubins(RRTStar):
 
     def draw_graph(self, rnd=None):
         plt.clf()
+        # for stopping simulation with the esc key.
+        plt.gcf().canvas.mpl_connect('key_release_event',
+                lambda event: [exit(0) if event.key == 'escape' else None])
         if rnd is not None:
             plt.plot(rnd.x, rnd.y, "^k")
         for node in self.node_list:
diff --git a/PathPlanning/RRTStarReedsShepp/rrt_star_reeds_shepp.py b/PathPlanning/RRTStarReedsShepp/rrt_star_reeds_shepp.py
index 5d78f98f..6ea66dc7 100644
--- a/PathPlanning/RRTStarReedsShepp/rrt_star_reeds_shepp.py
+++ b/PathPlanning/RRTStarReedsShepp/rrt_star_reeds_shepp.py
@@ -122,6 +122,9 @@ class RRTStarReedsShepp(RRTStar):
 
     def draw_graph(self, rnd=None):
         plt.clf()
+        # for stopping simulation with the esc key.
+        plt.gcf().canvas.mpl_connect('key_release_event',
+                lambda event: [exit(0) if event.key == 'escape' else None])
         if rnd is not None:
             plt.plot(rnd.x, rnd.y, "^k")
         for node in self.node_list:
diff --git a/PathPlanning/ReedsSheppPath/reeds_shepp_path_planning.py b/PathPlanning/ReedsSheppPath/reeds_shepp_path_planning.py
index 54b5adbe..fbf94957 100644
--- a/PathPlanning/ReedsSheppPath/reeds_shepp_path_planning.py
+++ b/PathPlanning/ReedsSheppPath/reeds_shepp_path_planning.py
@@ -395,6 +395,9 @@ def test():
 
         if show_animation:  # pragma: no cover
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.plot(px, py, label="final course " + str(mode))
 
             #  plotting
diff --git a/PathPlanning/VoronoiRoadMap/voronoi_road_map.py b/PathPlanning/VoronoiRoadMap/voronoi_road_map.py
index c73d6509..6db4bb26 100644
--- a/PathPlanning/VoronoiRoadMap/voronoi_road_map.py
+++ b/PathPlanning/VoronoiRoadMap/voronoi_road_map.py
@@ -185,6 +185,9 @@ def dijkstra_planning(sx, sy, gx, gy, ox, oy, rr, road_map, sample_x, sample_y):
         # show graph
         if show_animation and len(closedset.keys()) % 2 == 0:  # pragma: no cover
             plt.plot(current.x, current.y, "xg")
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.pause(0.001)
 
         if c_id == (len(road_map) - 1):
diff --git a/PathTracking/cgmres_nmpc/cgmres_nmpc.py b/PathTracking/cgmres_nmpc/cgmres_nmpc.py
index 74a0f9cc..98a12ab1 100644
--- a/PathTracking/cgmres_nmpc/cgmres_nmpc.py
+++ b/PathTracking/cgmres_nmpc/cgmres_nmpc.py
@@ -546,6 +546,9 @@ def animation(plant, controller, dt):
             steer = math.atan2(controller.history_u_2[t] * WB / v, 1.0)
 
         plt.cla()
+        # for stopping simulation with the esc key.
+        plt.gcf().canvas.mpl_connect('key_release_event',
+                lambda event: [exit(0) if event.key == 'escape' else None])
         plt.plot(plant.history_x, plant.history_y, "-r", label="trajectory")
         plot_car(x, y, yaw, steer=steer)
         plt.axis("equal")
diff --git a/PathTracking/lqr_speed_steer_control/lqr_speed_steer_control.py b/PathTracking/lqr_speed_steer_control/lqr_speed_steer_control.py
index c7c8e0dd..bd2e54bf 100644
--- a/PathTracking/lqr_speed_steer_control/lqr_speed_steer_control.py
+++ b/PathTracking/lqr_speed_steer_control/lqr_speed_steer_control.py
@@ -224,6 +224,9 @@ def do_simulation(cx, cy, cyaw, ck, speed_profile, goal):
 
         if target_ind % 1 == 0 and show_animation:
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.plot(cx, cy, "-r", label="course")
             plt.plot(x, y, "ob", label="trajectory")
             plt.plot(cx[target_ind], cy[target_ind], "xg", label="target")
diff --git a/PathTracking/lqr_steer_control/lqr_steer_control.py b/PathTracking/lqr_steer_control/lqr_steer_control.py
index b69577d3..6f01e5a8 100644
--- a/PathTracking/lqr_steer_control/lqr_steer_control.py
+++ b/PathTracking/lqr_steer_control/lqr_steer_control.py
@@ -203,6 +203,9 @@ def closed_loop_prediction(cx, cy, cyaw, ck, speed_profile, goal):
 
         if target_ind % 1 == 0 and show_animation:
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.plot(cx, cy, "-r", label="course")
             plt.plot(x, y, "ob", label="trajectory")
             plt.plot(cx[target_ind], cy[target_ind], "xg", label="target")
diff --git a/PathTracking/model_predictive_speed_and_steer_control/model_predictive_speed_and_steer_control.py b/PathTracking/model_predictive_speed_and_steer_control/model_predictive_speed_and_steer_control.py
index a16768e3..26e8e74f 100644
--- a/PathTracking/model_predictive_speed_and_steer_control/model_predictive_speed_and_steer_control.py
+++ b/PathTracking/model_predictive_speed_and_steer_control/model_predictive_speed_and_steer_control.py
@@ -429,6 +429,9 @@ def do_simulation(cx, cy, cyaw, ck, sp, dl, initial_state):
 
         if show_animation:  # pragma: no cover
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             if ox is not None:
                 plt.plot(ox, oy, "xr", label="MPC")
             plt.plot(cx, cy, "-r", label="course")
diff --git a/PathTracking/move_to_pose/move_to_pose.py b/PathTracking/move_to_pose/move_to_pose.py
index e161b461..2ae0090d 100644
--- a/PathTracking/move_to_pose/move_to_pose.py
+++ b/PathTracking/move_to_pose/move_to_pose.py
@@ -93,6 +93,10 @@ def plot_vehicle(x, y, theta, x_traj, y_traj):  # pragma: no cover
 
     plt.plot(x_traj, y_traj, 'b--')
 
+    # for stopping simulation with the esc key.
+    plt.gcf().canvas.mpl_connect('key_release_event',
+            lambda event: [exit(0) if event.key == 'escape' else None])
+
     plt.xlim(0, 20)
     plt.ylim(0, 20)
 
diff --git a/PathTracking/pure_pursuit/pure_pursuit.py b/PathTracking/pure_pursuit/pure_pursuit.py
index 370cac96..bcaf8697 100644
--- a/PathTracking/pure_pursuit/pure_pursuit.py
+++ b/PathTracking/pure_pursuit/pure_pursuit.py
@@ -3,6 +3,7 @@
 Path tracking simulation with pure pursuit steering control and PID speed control.
 
 author: Atsushi Sakai (@Atsushi_twi)
+        Guillaume Jacquenot (@Gjacquenot)
 
 """
 import numpy as np
@@ -17,7 +18,6 @@ dt = 0.1  # [s]
 L = 2.9  # [m] wheel base of vehicle
 
 
-old_nearest_point_index = None
 show_animation = True
 
 
@@ -31,17 +31,37 @@ class State:
         self.rear_x = self.x - ((L / 2) * math.cos(self.yaw))
         self.rear_y = self.y - ((L / 2) * math.sin(self.yaw))
 
+    def update(self, a, delta):
 
-def update(state, a, delta):
+        self.x += self.v * math.cos(self.yaw) * dt
+        self.y += self.v * math.sin(self.yaw) * dt
+        self.yaw += self.v / L * math.tan(delta) * dt
+        self.v += a * dt
+        self.rear_x = self.x - ((L / 2) * math.cos(self.yaw))
+        self.rear_y = self.y - ((L / 2) * math.sin(self.yaw))
 
-    state.x = state.x + state.v * math.cos(state.yaw) * dt
-    state.y = state.y + state.v * math.sin(state.yaw) * dt
-    state.yaw = state.yaw + state.v / L * math.tan(delta) * dt
-    state.v = state.v + a * dt
-    state.rear_x = state.x - ((L / 2) * math.cos(state.yaw))
-    state.rear_y = state.y - ((L / 2) * math.sin(state.yaw))
+    def calc_distance(self, point_x, point_y):
 
-    return state
+        dx = self.rear_x - point_x
+        dy = self.rear_y - point_y
+        return math.hypot(dx, dy)
+
+
+class States:
+
+    def __init__(self):
+        self.x = []
+        self.y = []
+        self.yaw = []
+        self.v = []
+        self.t = []
+
+    def append(self, t , state):
+        self.x.append(state.x)
+        self.y.append(state.y)
+        self.yaw.append(state.yaw)
+        self.v.append(state.v)
+        self.t.append(t)
 
 
 def PIDControl(target, current):
@@ -50,20 +70,57 @@ def PIDControl(target, current):
     return a
 
 
-def pure_pursuit_control(state, cx, cy, pind):
+class Trajectory:
+    def __init__(self, cx, cy):
+        self.cx = cx
+        self.cy = cy
+        self.old_nearest_point_index = None
 
-    ind = calc_target_index(state, cx, cy)
+    def search_target_index(self, state):
+        if self.old_nearest_point_index is None:
+            # search nearest point index
+            dx = [state.rear_x - icx for icx in self.cx]
+            dy = [state.rear_y - icy for icy in self.cy]
+            d = np.hypot(dx, dy)
+            ind = np.argmin(d)
+            self.old_nearest_point_index = ind
+        else:
+            ind = self.old_nearest_point_index
+            distance_this_index = state.calc_distance(self.cx[ind], self.cy[ind])
+            while True:
+                ind = ind + 1 if (ind + 1) < len(self.cx) else ind
+                distance_next_index = state.calc_distance(self.cx[ind], self.cy[ind])
+                if distance_this_index < distance_next_index:
+                    break
+                distance_this_index = distance_next_index
+            self.old_nearest_point_index = ind
+
+        L = 0.0
+
+        Lf = k * state.v + Lfc
+
+        # search look ahead target point index
+        while Lf > L and (ind + 1) < len(self.cx):
+            L = state.calc_distance(self.cx[ind], self.cy[ind])
+            ind += 1
+
+        return ind
+
+
+def pure_pursuit_control(state, trajectory, pind):
+
+    ind = trajectory.search_target_index(state)
 
     if pind >= ind:
         ind = pind
 
-    if ind < len(cx):
-        tx = cx[ind]
-        ty = cy[ind]
+    if ind < len(trajectory.cx):
+        tx = trajectory.cx[ind]
+        ty = trajectory.cy[ind]
     else:
-        tx = cx[-1]
-        ty = cy[-1]
-        ind = len(cx) - 1
+        tx = trajectory.cx[-1]
+        ty = trajectory.cy[-1]
+        ind = len(trajectory.cx) - 1
 
     alpha = math.atan2(ty - state.rear_y, tx - state.rear_x) - state.yaw
 
@@ -73,48 +130,6 @@ def pure_pursuit_control(state, cx, cy, pind):
 
     return delta, ind
 
-def calc_distance(state, point_x, point_y):
-
-    dx = state.rear_x - point_x
-    dy = state.rear_y - point_y
-    return math.hypot(dx, dy)
-
-
-def calc_target_index(state, cx, cy):
-
-    global old_nearest_point_index
-
-    if old_nearest_point_index is None:
-        # search nearest point index
-        dx = [state.rear_x - icx for icx in cx]
-        dy = [state.rear_y - icy for icy in cy]
-        d = [idx ** 2 + idy ** 2 for (idx, idy) in zip(dx, dy)]
-        ind = d.index(min(d))
-        old_nearest_point_index = ind
-    else:
-        ind = old_nearest_point_index
-        distance_this_index = calc_distance(state, cx[ind], cy[ind])
-        while True:
-            ind = ind + 1 if (ind + 1) < len(cx) else ind
-            distance_next_index = calc_distance(state, cx[ind], cy[ind])
-            if distance_this_index < distance_next_index:
-                break
-            distance_this_index = distance_next_index
-        old_nearest_point_index = ind
-
-    L = 0.0
-
-    Lf = k * state.v + Lfc
-
-    # search look ahead target point index
-    while Lf > L and (ind + 1) < len(cx):
-        dx = cx[ind] - state.rear_x
-        dy = cy[ind] - state.rear_y
-        L = math.hypot(dx, dy)
-        ind += 1
-
-    return ind
-
 
 def plot_arrow(x, y, yaw, length=1.0, width=0.5, fc="r", ec="k"):
     """
@@ -122,7 +137,7 @@ def plot_arrow(x, y, yaw, length=1.0, width=0.5, fc="r", ec="k"):
     """
 
     if not isinstance(x, float):
-        for (ix, iy, iyaw) in zip(x, y, yaw):
+        for ix, iy, iyaw in zip(x, y, yaw):
             plot_arrow(ix, iy, iyaw)
     else:
         plt.arrow(x, y, length * math.cos(yaw), length * math.sin(yaw),
@@ -144,31 +159,27 @@ def main():
 
     lastIndex = len(cx) - 1
     time = 0.0
-    x = [state.x]
-    y = [state.y]
-    yaw = [state.yaw]
-    v = [state.v]
-    t = [0.0]
-    target_ind = calc_target_index(state, cx, cy)
+    states = States()
+    states.append(time, state)
+    trajectory = Trajectory(cx, cy)
+    target_ind = trajectory.search_target_index(state)
 
     while T >= time and lastIndex > target_ind:
         ai = PIDControl(target_speed, state.v)
-        di, target_ind = pure_pursuit_control(state, cx, cy, target_ind)
-        state = update(state, ai, di)
+        di, target_ind = pure_pursuit_control(state, trajectory, target_ind)
+        state.update(ai, di)
 
-        time = time + dt
-
-        x.append(state.x)
-        y.append(state.y)
-        yaw.append(state.yaw)
-        v.append(state.v)
-        t.append(time)
+        time += dt
+        states.append(time, state)
 
         if show_animation:  # pragma: no cover
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plot_arrow(state.x, state.y, state.yaw)
             plt.plot(cx, cy, "-r", label="course")
-            plt.plot(x, y, "-b", label="trajectory")
+            plt.plot(states.x, states.y, "-b", label="trajectory")
             plt.plot(cx[target_ind], cy[target_ind], "xg", label="target")
             plt.axis("equal")
             plt.grid(True)
@@ -181,7 +192,7 @@ def main():
     if show_animation:  # pragma: no cover
         plt.cla()
         plt.plot(cx, cy, ".r", label="course")
-        plt.plot(x, y, "-b", label="trajectory")
+        plt.plot(states.x, states.y, "-b", label="trajectory")
         plt.legend()
         plt.xlabel("x[m]")
         plt.ylabel("y[m]")
@@ -189,7 +200,7 @@ def main():
         plt.grid(True)
 
         plt.subplots(1)
-        plt.plot(t, [iv * 3.6 for iv in v], "-r")
+        plt.plot(states.t, [iv * 3.6 for iv in states.v], "-r")
         plt.xlabel("Time[s]")
         plt.ylabel("Speed[km/h]")
         plt.grid(True)
diff --git a/PathTracking/rear_wheel_feedback/rear_wheel_feedback.py b/PathTracking/rear_wheel_feedback/rear_wheel_feedback.py
index bf4f31b3..758e9ad9 100644
--- a/PathTracking/rear_wheel_feedback/rear_wheel_feedback.py
+++ b/PathTracking/rear_wheel_feedback/rear_wheel_feedback.py
@@ -149,6 +149,9 @@ def closed_loop_prediction(cx, cy, cyaw, ck, speed_profile, goal):
 
         if target_ind % 1 == 0 and show_animation:
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.plot(cx, cy, "-r", label="course")
             plt.plot(x, y, "ob", label="trajectory")
             plt.plot(cx[target_ind], cy[target_ind], "xg", label="target")
diff --git a/PathTracking/stanley_controller/stanley_controller.py b/PathTracking/stanley_controller/stanley_controller.py
index 9b808dd9..2af3989f 100644
--- a/PathTracking/stanley_controller/stanley_controller.py
+++ b/PathTracking/stanley_controller/stanley_controller.py
@@ -185,6 +185,9 @@ def main():
 
         if show_animation:  # pragma: no cover
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.plot(cx, cy, ".r", label="course")
             plt.plot(x, y, "-b", label="trajectory")
             plt.plot(cx[target_idx], cy[target_idx], "xg", label="target")
diff --git a/README.md b/README.md
index e740049b..ec428127 100644
--- a/README.md
+++ b/README.md
@@ -605,5 +605,8 @@ This is a list: [Users comments](https://github.com/AtsushiSakai/PythonRobotics/
 
 - [Ryohei Sasaki](https://github.com/rsasaki0109)
 
+- [Göktuğ Karakaşlı](https://github.com/goktug97)
+
+- [Guillaume Jacquenot](https://github.com/Gjacquenot)
 
 
diff --git a/SLAM/EKFSLAM/ekf_slam.py b/SLAM/EKFSLAM/ekf_slam.py
index 66234b57..3038e40a 100644
--- a/SLAM/EKFSLAM/ekf_slam.py
+++ b/SLAM/EKFSLAM/ekf_slam.py
@@ -235,6 +235,9 @@ def main():
 
         if show_animation:  # pragma: no cover
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
 
             plt.plot(RFID[:, 0], RFID[:, 1], "*k")
             plt.plot(xEst[0], xEst[1], ".r")
diff --git a/SLAM/FastSLAM1/fast_slam1.py b/SLAM/FastSLAM1/fast_slam1.py
index 298cc036..2d7c0037 100644
--- a/SLAM/FastSLAM1/fast_slam1.py
+++ b/SLAM/FastSLAM1/fast_slam1.py
@@ -365,6 +365,9 @@ def main():
 
         if show_animation:  # pragma: no cover
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.plot(RFID[:, 0], RFID[:, 1], "*k")
 
             for i in range(N_PARTICLE):
diff --git a/SLAM/FastSLAM2/fast_slam2.py b/SLAM/FastSLAM2/fast_slam2.py
index b9df6948..86881222 100644
--- a/SLAM/FastSLAM2/fast_slam2.py
+++ b/SLAM/FastSLAM2/fast_slam2.py
@@ -390,6 +390,9 @@ def main():
 
         if show_animation:  # pragma: no cover
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.plot(RFID[:, 0], RFID[:, 1], "*k")
 
             for iz in range(len(z[:, 0])):
diff --git a/SLAM/GraphBasedSLAM/graph_based_slam.py b/SLAM/GraphBasedSLAM/graph_based_slam.py
index 41b9d525..9bb68c28 100644
--- a/SLAM/GraphBasedSLAM/graph_based_slam.py
+++ b/SLAM/GraphBasedSLAM/graph_based_slam.py
@@ -303,7 +303,9 @@ def main():
 
             if show_animation:  # pragma: no cover
                 plt.cla()
-
+                # for stopping simulation with the esc key.
+                plt.gcf().canvas.mpl_connect('key_release_event',
+                        lambda event: [exit(0) if event.key == 'escape' else None])
                 plt.plot(RFID[:, 0], RFID[:, 1], "*k")
 
                 plt.plot(hxTrue[0, :].flatten(),
@@ -319,4 +321,4 @@ def main():
 
 
 if __name__ == '__main__':
-    main()
\ No newline at end of file
+    main()
diff --git a/SLAM/iterative_closest_point/iterative_closest_point.py b/SLAM/iterative_closest_point/iterative_closest_point.py
index 3512ef97..0b280260 100644
--- a/SLAM/iterative_closest_point/iterative_closest_point.py
+++ b/SLAM/iterative_closest_point/iterative_closest_point.py
@@ -36,6 +36,9 @@ def icp_matching(previous_points, current_points):
 
         if show_animation:  # pragma: no cover
             plt.cla()
+            # for stopping simulation with the esc key.
+            plt.gcf().canvas.mpl_connect('key_release_event',
+                    lambda event: [exit(0) if event.key == 'escape' else None])
             plt.plot(previous_points[0, :], previous_points[1, :], ".r")
             plt.plot(current_points[0, :], current_points[1, :], ".b")
             plt.plot(0.0, 0.0, "xr")
diff --git a/environment.yml b/environment.yml
index 28ff9f1b..6866ed93 100644
--- a/environment.yml
+++ b/environment.yml
@@ -1,9 +1,11 @@
 name: python_robotics
 dependencies:
 - python
+- pip
 - matplotlib
 - scipy
 - numpy==1.15
 - pandas
+- coverage
 - pip:
     - cvxpy
diff --git a/users_comments.md b/users_comments.md
index 2cfd7a4a..792f3a4d 100644
--- a/users_comments.md
+++ b/users_comments.md
@@ -404,6 +404,9 @@ URL: https://www.semanticscholar.org/paper/A-Review-of-Robot-Rescue-Simulation-P
 7. Ghosh, Ritwika, et al. "CyPhyHouse: A Programming, Simulation, and Deployment Toolchain for Heterogeneous Distributed Coordination." arXiv preprint arXiv:1910.01557 (2019).
 URL: https://arxiv.org/abs/1910.01557
 
+8. Hahn, Carsten, et al. "Dynamic Path Planning with Stable Growing Neural Gas." (2019).
+URL: https://pdfs.semanticscholar.org/5c06/f3cb9542a51e1bf1a32523c1bc7fea6cecc5.pdf
+
 # Others
 
 - Autonomous Vehicle Readings https://richardkelley.io/readings