for instance, when I recalculate occupancy grid data from some of the poses (x,y) I calculated from ee_grid, I end up with cells that do not have a value of 0. The problem is this doesn't seem to work. Self.cells_array.append(self.pose_calculator(self.cells))Īs seen above ee_grid is supposed to hold all cells with value 0(unoccupied cells) and I try to use map,resolution,origin,width and height. Y=(grid_location * self.resolution) + self.origin_y X=(grid_location*self.resolution)+self.origin_x This represents a 2-D grid map, in which each cell represents the probability of occupancy. I found the package movebase that seems to do that but I could not understand how to connect it to. In this case, this would be outdoor navigation. Now a I want to use this data to navigate the robot autonomously. Self.origin_y = self.occ_.yĮ_column = ((index - e_row) / self.width) I was able to apply rtabmap and build a occupancy grid and a point cloud for the ground plane and a pointcloud for the obstacles. Self.fullmap = np.array(self.occ_gridmap.data) Self.occ_gridmap = rospy.wait_for_message("/map", OccupancyGrid) Here are several snippets on how I plan to accomplish this, please be aware that alot of the code before and inbetween have been skipped to cut out information unimportant to the focus of this question. I need to do so for an algorithm I'm working on. The first is creating an occupancy grid, the second is getting data from the RPlidar. The map data, in row-major order, starting with (0,0). I wish to use the map int8 data which contains the probability of occupancy of each grid. This represents a 2-D grid map, in which each cell represents the probability of. by the LIDAR, ultrasonic sensor, or some other object detection sensor) would be marked -1.I wish to be able to calculate the pose(x,y) of any unoccupied grid in the occupancy grid from the occupancyGrid message type here. The number is often 0 (free space) to 100 (100% likely occupied). In an occupancy grid map, each cell is marked with a number that indicates the likelihood the cell contains an object. Thus, for a 0.1 resolution grid map, a robot that reports its position as (3.5, 4.3) corresponds to a grid map location of (35, 43). What would the corresponding location be on the grid map? On the grid cell, this location would correspond to cell (x=3, y=4) because the grid map is 1 meter resolution.īut what if we wanted to change the map resolution to 0.1 meter spacing between each grid cell? Let’s suppose the robot reported its location as (3.5, 4.3).
For example, let’s say a robot’s location in the real world is recorded as (3.5, 4.3). One other thing we need to keep in mind is that I assumed the map above has 1 meter spacing between each grid cell. Knowing what part of a factory floor is open space and what part of a factory floor contains obstacles helps a robot properly plan the shortest, collision-free path from one point to another. add list of points (in a ROS FloatArrayBare structure) to the occupancy grid. A robot’s position in the environment at any given time is relative to the corner of the map (x=0, y=0).
0 means completely free, 100 means completely occupied, and the special value - 1 is completely unknown. ROS interface: Grid maps can be directly converted to and from ROS message types such as PointCloud2, OccupancyGrid, GridCells, and our custom GridMap message. At this time, the occupancy is expressed as an integer in the range of 0-100. We can use a grid map to abstractly represent any indoor environment, including a house, apartment, and office. When ROS messages communicate, the data type is navmsgs::OccupancyGrid. However, open factory floor is located at (x=3, y=3). For example, we can see in the image above that a shelf is located at (x=6, y=8). The cool thing about a grid map is that we can determine what is in each cell by looking up the coordinate. An overhead view of a factory floor represented abstractly as a grid map with 1 meter x 1 meter cells.