DRAFT: time based path planners

PathPlanning/TimeBasedPathPlanning/moving_obstacles.py

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+import numpy as np
+import random
+import matplotlib.pyplot as plt
+
+class Grid():
+
+    # Set in constructor
+    grid_size = None
+    grid = None
+    obstacle_paths = []
+
+    # Problem definition
+    time_limit = 100
+    num_obstacles = 2
+
+    def __init__(self, grid_size: np.ndarray[int, int]):
+        self.grid_size = grid_size
+        self.grid = np.zeros((grid_size[0], grid_size[1], self.time_limit))
+
+        for i in range(1, self.num_obstacles+1):
+            self.obstacle_paths.append(self.generate_dynamic_obstacle(i))
+
+    def generate_dynamic_obstacle(self, obs_idx: int) -> list[np.ndarray[int, int]]:
+        # TODO: dont spawn on another obstacle
+        initial_position = (np.random.randint(0, self.grid_size[0]), np.random.randint(0, self.grid_size[1]))
+        positions = [initial_position]
+        print("Initial position: ", initial_position)
+
+        diffs = [np.array([0, 1]), np.array([0, -1]), np.array([1, 0]), np.array([-1, 0]), np.array([0, 0])]
+
+        for t in range(1, self.time_limit-1):
+            random.shuffle(diffs)
+            for diff in diffs:
+                new_position = positions[-1] + diff
+
+                # Check if new position is in grid
+                if new_position[0] < 0 or new_position[0] >= self.grid_size[0] or new_position[1] < 0 or new_position[1] >= self.grid_size[1]:
+                    continue
+
+                # Check if new position occupied by another obstacle
+                if self.grid[new_position[0], new_position[1], t] == 0:
+                    positions.append(new_position)
+                    self.grid[new_position[0], new_position[1], t] = obs_idx
+                    break
+
+                # Impossible situation for obstacle - stay in place
+                print("Impossible situation for obstacle!")
+                positions.append(positions[-1])
+
+        return positions
+
+show_animation = True
+
+def main():
+    grid = Grid(np.array([10, 10]))
+
+    plt.figure()
+
+    for t in range(0, grid.time_limit):
+        plt.clf()
+
+        if show_animation:  # pragma: no cover
+            # TODO: iter is clunky. Should use np array
+            ax = plt.axes()
+            ax.set_xlim(0, grid.grid_size[0])
+            ax.set_ylim(0, grid.grid_size[1])
+
+            for (obs_idx, obs_path) in enumerate(grid.obstacle_paths):
+                obs_pos = obs_path[t]
+                # plt.plot(obs_pos[0], obs_pos[1], "xr")
+                circle = plt.Circle((obs_pos[0], obs_pos[1]), 0.2)
+                ax.add_patch(circle)
+            plt.grid(True)
+            plt.pause(0.3)
+
+# TODO: better animation closing
+# fig, ax = plt.subplots()
+# line, = ax.plot([], [])
+# ax.set_xlim(0, 10)
+# ax.set_ylim(-1, 1)
+
+# def init():
+#     line.set_data([], [])
+#     return line,
+
+# def animate(i):
+#     x = [0, 10]
+#     y = [0, i % 2 * 2 - 1]
+#     line.set_data(x, y)
+#     return line,
+
+# ani = animation.FuncAnimation(fig, animate, init_func=init, frames=100, interval=20, blit=True)
+
+# def close_event(evt):
+#     ani.event_source.stop()
+#     plt.close(fig)
+
+if __name__ == '__main__':
+    main()