ROS中的珊格地图——nav_msgs::OccupancyGrid

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目录

• 一、Rviz中的地图效果如下：
• 二、地图数据格式
• 三、实例代码

一、Rviz中的地图效果如下：

黑色块为障碍物，颜色较深的灰色块为危险区，颜色再浅一点的是可行区域，最浅的是未知区域（最外围的区域）；

二、地图数据格式

官方数据类型解释如下：

# This represents a 2-D grid map, in which each cell represents the probability of
# occupancy.

Header header 

#MetaData for the map
MapMetaData info

# The map data, in row-major order, starting with (0,0).  Occupancy
# probabilities are in the range [0,100].  Unknown is -1.
int8[] data

# This hold basic information about the characterists of the OccupancyGrid

# The time at which the map was loaded
time map_load_time
# The map resolution [m/cell]
float32 resolution
# Map width [cells]
uint32 width
# Map height [cells]
uint32 height
# The origin of the map [m, m, rad].  This is the real-world pose of the
# cell (0,0) in the map.
geometry_msgs/Pose origin

栅格地图中坐标是一维数组的形式，比如实际地图中某点坐标为(x,y)，对应栅格地图中坐标为[x*map.info.width+y]。

三、实例代码

ros::Publisher mapPub = nodeHandler.advertise<nav_msgs::OccupancyGrid>("laser_map", 1, true);

//发布地图．
void PublishMap(ros::Publisher &map_pub)
{
    nav_msgs::OccupancyGrid rosMap;

    rosMap.info.resolution = mapParams.resolution;
    rosMap.info.origin.position.x = 0.0;
    rosMap.info.origin.position.y = 0.0;
    rosMap.info.origin.position.z = 0.0;
    rosMap.info.origin.orientation.x = 0.0;
    rosMap.info.origin.orientation.y = 0.0;
    rosMap.info.origin.orientation.z = 0.0;
    rosMap.info.origin.orientation.w = 1.0;

    rosMap.info.origin.position.x = mapParams.origin_x;
    rosMap.info.origin.position.y = mapParams.origin_y;
    rosMap.info.width = mapParams.width;
    rosMap.info.height = mapParams.height;
    rosMap.data.resize(rosMap.info.width * rosMap.info.height);

    //0~100
    int cnt0, cnt1, cnt2;
    cnt0 = cnt1 = cnt2 = 100;
    for (int i = 0; i < mapParams.width * mapParams.height; i++)
    {
        if (pMap[i] == 50)
        {
            rosMap.data[i] = -1.0;
        }
        else
        {

            rosMap.data[i] = pMap[i];
        }
    }

    rosMap.header.stamp = ros::Time::now();
    rosMap.header.frame_id = "map";

    map_pub.publish(rosMap);
}