first release grid based_sweep_planner.py

Author: AtsushiSakai

Mapping/grid_map_lib/__init__.py

@@ -185,13 +185,14 @@ def check_inside_polygon(iox, ioy, x, y):
 
         return inside
 
-    def plot_grid_map(self):
+    def plot_grid_map(self, ax=None):
 
         grid_data = np.reshape(np.array(self.data), (self.height, self.width))
-        fig, ax = plt.subplots()
+        if not ax:
+            fig, ax = plt.subplots()
         heat_map = ax.pcolor(grid_data, cmap="Blues", vmin=0.0, vmax=1.0)
         plt.axis("equal")
-        plt.show()
+        # plt.show()
 
         return heat_map
 

Mapping/grid_map_lib/grid_map_lib.py

@@ -0,0 +1,274 @@
+"""
+Grid based sweep planner
+
+author: Atsushi Sakai
+"""
+
+import math
+import os
+import sys
+
+import matplotlib.pyplot as plt
+import numpy as np
+
+sys.path.append(os.path.relpath("../../Mapping/grid_map_lib/"))
+from grid_map_lib import GridMap
+
+
+class SweepSearcher:
+
+    def __init__(self, mdirection, sdirection, xinds_miny, miny):
+        self.moving_direction = mdirection  # +1 or -1
+        self.sweep_direction = sdirection  # +1 or -1
+        self.turing_window = []
+        self.update_turning_window()
+        self.xinds_miny = xinds_miny
+        self.miny = miny
+
+    def move_target_grid(self, cxind, cyind, gmap):
+
+        nxind = self.moving_direction + cxind
+        nyind = cyind
+
+        # found safe grid
+        if not gmap.check_occupied_from_xy_index(nxind, nyind, occupied_val=0.5):
+            return nxind, nyind
+        else:  # occupided
+            ncxind, ncyind = self.find_safe_turning_grid(cxind, cyind, gmap)
+            if not ncxind and not ncyind:
+                # moving backward
+                ncxind = -self.moving_direction + cxind
+                ncyind = cyind
+                if gmap.check_occupied_from_xy_index(ncxind, ncyind):
+                    # moved backward, but the grid is occupied by obstacle
+                    return None, None
+            else:
+                self.swap_moving_direction()
+            return ncxind, ncyind
+
+    def find_safe_turning_grid(self, cxind, cyind, gmap):
+
+        for (dxind, dyind) in self.turing_window:
+
+            nxind = dxind + cxind
+            nyind = dyind + cyind
+
+            # found safe grid
+            if not gmap.check_occupied_from_xy_index(nxind, nyind, occupied_val=0.5):
+                print(dxind, dyind)
+                return nxind, nyind
+
+        return None, None
+
+    def is_search_done(self, gmap):
+        for ix in self.xinds_miny:
+            if not gmap.check_occupied_from_xy_index(ix, self.miny, occupied_val=0.5):
+                return False
+
+        # all lower grid is occupied
+        return True
+
+    def update_turning_window(self):
+        self.turing_window = [
+            (self.moving_direction, 0.0),
+            (self.moving_direction, self.sweep_direction),
+            (0, self.sweep_direction),
+            (-self.moving_direction, self.sweep_direction),
+        ]
+
+    def swap_moving_direction(self):
+        self.moving_direction *= -1
+        self.update_turning_window()
+
+
+def find_sweep_direction_and_start_posi(ox, oy, start_posi):
+    # find sweep_direction
+    maxd_id = None
+    maxd = 0.0
+    vec = [0.0, 0.0]
+    for i in range(len(ox) - 1):
+        dx = ox[i + 1] - ox[i]
+        dy = oy[i + 1] - oy[i]
+        d = np.sqrt(dx ** 2 + dy ** 2)
+
+        if d > maxd:
+            maxd_id = i
+            maxd = d
+            vec = [dx, dy]
+
+    # find sweep start posi
+    d1 = np.sqrt((ox[maxd_id] - start_posi[0]) ** 2 +
+                 (oy[maxd_id] - start_posi[1]) ** 2)
+    d2 = np.sqrt((ox[maxd_id + 1] - start_posi[0]) ** 2 +
+                 (oy[maxd_id + 1] - start_posi[1]) ** 2)
+
+    if d2 >= d1:  # first point is near
+        sweep_start_posi = [ox[maxd_id], oy[maxd_id]]
+    else:
+        sweep_start_posi = [ox[maxd_id + 1], oy[maxd_id + 1]]
+        vec = [-1.0 * iv for iv in vec]  # reverse direction
+
+    return vec, sweep_start_posi
+
+
+def convert_grid_coordinate(ox, oy, sweep_vec, sweep_start_posi):
+    tx = [ix - sweep_start_posi[0] for ix in ox]
+    ty = [iy - sweep_start_posi[1] for iy in oy]
+
+    th = math.atan2(sweep_vec[1], sweep_vec[0])
+
+    c = np.cos(-th)
+    s = np.sin(-th)
+
+    rx = [ix * c - iy * s for (ix, iy) in zip(tx, ty)]
+    ry = [ix * s + iy * c for (ix, iy) in zip(tx, ty)]
+
+    return rx, ry
+
+
+def convert_global_coordinate(x, y, sweep_vec, sweep_start_posi):
+    th = math.atan2(sweep_vec[1], sweep_vec[0])
+    c = np.cos(th)
+    s = np.sin(th)
+
+    tx = [ix * c - iy * s for (ix, iy) in zip(x, y)]
+    ty = [ix * s + iy * c for (ix, iy) in zip(x, y)]
+
+    rx = [ix + sweep_start_posi[0] for ix in tx]
+    ry = [iy + sweep_start_posi[1] for iy in ty]
+
+    return rx, ry
+
+
+def search_free_lower_y_grid_index(grid_map):
+    miny = None
+    xinds = []
+
+    for iy in range(grid_map.height):
+        for ix in range(grid_map.width):
+            if not grid_map.check_occupied_from_xy_index(ix, iy):
+                miny = iy
+                xinds.append(ix)
+        if miny:
+            break
+
+    return xinds, miny
+
+
+def setup_grid_map(ox, oy, reso):
+    offset_grid = 10
+
+    width = math.ceil((max(ox) - min(ox)) / reso) + offset_grid
+    height = math.ceil((max(oy) - min(oy)) / reso) + offset_grid
+    center_x = np.mean(ox)
+    center_y = np.mean(oy)
+
+    grid_map = GridMap(width, height, reso, center_x, center_y)
+
+    grid_map.set_value_from_polygon(ox, oy, 1.0, inside=False)
+
+    # fill grid
+    # for i in range(len(ox) - 1):
+    #     grid_map.set_value_from_xy_pos(ox[i], oy[i], 1.0)
+    #
+    #     x, y = ox[i], oy[i]
+    #     th = math.atan2(oy[i + 1] - oy[i], ox[i + 1] - ox[i])
+    #     d = np.sqrt((x - ox[i + 1])**2 + (y - oy[i + 1])**2)
+    #
+    #     while d > reso:
+    #         x += np.cos(th) * reso
+    #         y += np.sin(th) * reso
+    #         d = np.sqrt((x - ox[i + 1])**2 + (y - oy[i + 1])**2)
+    #
+    #     grid_map.set_value_from_xy_pos(x, y, 1.0)
+
+    xinds, miny = search_free_lower_y_grid_index(grid_map)
+
+    # grid_map.plot_gridmap()
+
+    return grid_map, xinds, miny
+
+
+def sweep_path_search(sweep_searcher, gmap, start_posi):
+    sx, sy = start_posi[0], start_posi[1]
+    # print(sx, sy)
+
+    # search start grid
+    cxind, cyind = gmap.get_xy_index_from_xy_pos(sx, sy)
+    if gmap.check_occupied_from_xy_index(cxind, cyind):
+        cxind, cyind = sweep_searcher.find_safe_turning_grid(cxind, cyind, gmap)
+    gmap.set_value_from_xy_index(cxind, cyind, 0.5)
+
+    px, py = [], []
+
+    # fig, ax = plt.subplots()
+
+    while True:
+
+        cxind, cyind = sweep_searcher.move_target_grid(cxind, cyind, gmap)
+
+        if sweep_searcher.is_search_done(gmap) or (not cxind and not cyind):
+            print("Done")
+            break
+
+        x, y = gmap.calc_grid_central_xy_position_from_xy_index(
+            cxind, cyind)
+
+        px.append(x)
+        py.append(y)
+
+        gmap.set_value_from_xy_index(cxind, cyind, 0.5)
+
+        # gmap.plot_grid_map(ax=ax)
+        # plt.pause(0.1)
+
+    gmap.plot_grid_map()
+
+    return px, py
+
+
+def planning(ox, oy, reso, start_posi):
+    sweep_vec, sweep_start_posi = find_sweep_direction_and_start_posi(
+        ox, oy, start_posi)
+
+    rox, roy = convert_grid_coordinate(ox, oy, sweep_vec, sweep_start_posi)
+
+    moving_direction = 1
+    sweeping_direction = -1
+
+    gmap, xinds_miny, miny = setup_grid_map(rox, roy, reso)
+
+    sweep_searcher = SweepSearcher(moving_direction, sweeping_direction, xinds_miny, miny)
+
+    px, py = sweep_path_search(sweep_searcher, gmap, start_posi)
+
+    rx, ry = convert_global_coordinate(px, py, sweep_vec, sweep_start_posi)
+
+    return rx, ry
+
+
+def main():
+    print("start!!")
+
+    start_posi = [0.0, 0.0]
+
+    ox = [0.0, 20.0, 50.0, 100.0, 130.0, 40.0, 0.0]
+    oy = [0.0, -20.0, 0.0, 30.0, 60.0, 80.0, 0.0]
+    reso = 5.0
+
+    px, py = planning(ox, oy, reso, start_posi)
+
+    plt.subplots()
+
+    plt.plot(start_posi[0], start_posi[1], "or")
+    plt.plot(ox, oy, "-xb")
+    plt.plot(px, py, "-r")
+    plt.axis("equal")
+    plt.grid(True)
+    plt.show()
+
+    print("done!!")
+
+
+if __name__ == '__main__':
+    main()