robot_pose_ekf 使用说明

协方差参数的设置

主要确定mpu6050和odom编码器协方差参数的设置
参考：turtlebot_node协方差的设置

mpu605参数的设置

参考：https://github.com/Arkapravo/turtlebot/blob/master/turtlebot_node/src/turtlebot_node/gyro.py

self.imu_data.orientation_covariance = [1e6, 0, 0, 0, 1e6, 0, 0, 0, 1e-6]
self.imu_data.angular_velocity_covariance = [1e6, 0, 0, 0, 1e6, 0, 0, 0, 1e-6]
self.imu_data.linear_acceleration_covariance = [-1,0,0,0,0,0,0,0,0]

odom参数的设置

参考：

• https://github.com/Arkapravo/turtlebot/blob/master/turtlebot_node/src/turtlebot_node/covariances.py
• https://github.com/Arkapravo/turtlebot/blob/master/turtlebot_node/nodes/turtlebot_node.py

有两组协方差，在底盘运动时，取第一组数据；在底盘静止时，取第二组数据。

ODOM_POSE_COVARIANCE = [1e-3, 0, 0, 0, 0, 0, 
                        0, 1e-3, 0, 0, 0, 0,
                        0, 0, 1e6, 0, 0, 0,
                        0, 0, 0, 1e6, 0, 0,
                        0, 0, 0, 0, 1e6, 0,
                        0, 0, 0, 0, 0, 1e3]
ODOM_POSE_COVARIANCE2 = [1e-9, 0, 0, 0, 0, 0, 
                         0, 1e-3, 1e-9, 0, 0, 0,
                         0, 0, 1e6, 0, 0, 0,
                         0, 0, 0, 1e6, 0, 0,
                         0, 0, 0, 0, 1e6, 0,
                         0, 0, 0, 0, 0, 1e-9]

ODOM_TWIST_COVARIANCE = [1e-3, 0, 0, 0, 0, 0, 
                         0, 1e-3, 0, 0, 0, 0,
                         0, 0, 1e6, 0, 0, 0,
                         0, 0, 0, 1e6, 0, 0,
                         0, 0, 0, 0, 1e6, 0,
                         0, 0, 0, 0, 0, 1e3]
ODOM_TWIST_COVARIANCE2 = [1e-9, 0, 0, 0, 0, 0, 
                          0, 1e-3, 1e-9, 0, 0, 0,
                          0, 0, 1e6, 0, 0, 0,
                          0, 0, 0, 1e6, 0, 0,
                          0, 0, 0, 0, 1e6, 0,
                          0, 0, 0, 0, 0, 1e-9]

        if sensor_state.requested_right_velocity == 0 and \
               sensor_state.requested_left_velocity == 0 and \
               sensor_state.distance == 0:
            odom.pose.covariance = ODOM_POSE_COVARIANCE2
            odom.twist.covariance = ODOM_TWIST_COVARIANCE2
        else:
            odom.pose.covariance = ODOM_POSE_COVARIANCE
            odom.twist.covariance = ODOM_TWIST_COVARIANCE

配置robot_pose_ekf

robot_pose_ekf.launch内容如下

"robot_pose_ekf" type="robot_pose_ekf" name="robot_pose_ekf">
  <param name="output_frame" value="odom_combined"/>
  <param name="base_footprint_frame" value="base_footprint"/>
  <param name="freq" value="30.0"/>
  <param name="sensor_timeout" value="1.0"/>  
  <param name="odom_used" value="true"/>
  <param name="imu_used" value="true"/>
  <param name="vo_used" value="false"/>

  from="imu_data" to="imu" />

默认监听topic: imu_data、odom和vo
发布robot_pose_ekf/odom_combined和坐标系转换

运行

roslaunch mpu6050_serial_to_imu demo.launch
roslaunch dashgo_bringup  robot_pose_ekf.launch
rostopic echo /robot_pose_ekf/odom_combined

问题

imu不生效
https://chidambaramsethu.wordpress.com/2013/07/15/a-beginners-guide-to-the-the-ros-robot_pose_ekf-package/

robot_localization

另外一个： http://wiki.ros.org/robot_localization
ROSCon 2015 Hamburg: Day 2 - Tom Moore: Working with the robot localization Package