自主导航与远程控制中的速度优化velocity_smoother与多路输入切换cmd_vel_mux的层次关系(ros/ cmd_vel)

         利用机器人操作系统ros对机器人进行控制，自主导航navigation输出的速度由于加速度大，会造成小车震动，需要进行速度平滑。

而实际运行时，还可以用用手柄，键盘，安卓app等对机器人进行操作，同一时刻控制小车运动，小车发生混乱，各种控制方式需要切换，因此需要用到cmd_vel_mux对多路速度进行切换，划分优先级。

键盘控制／节点node（话题topic）:    keyop(key_cmd_vel)

手柄控制／节点node（话题topic）:　joyop(joy_cmd_vel)

自主导航／节点node（话题topic）:     navigation(cmd_vel)

速度平滑／节点node（话题topic）: velocity_smoother(cmd_vel_smooth)

       http://wiki.ros.org/yocs_velocity_smoother?distro=indigo

控制方式切换／节点node（话题topic）:cmd_vel_mux(cmd_vel_mux)

　　　　　http://wiki.ros.org/yocs_cmd_vel_mux?distro=indigo

基座　：mobile_base

一直很疑惑到底如何切换，然后看到资料Kobuki'sControlSystem（http://wiki.ros.org/kobuki/Tutorials/Kobuki%27s%20Control%20System）。　其中这样一段话：

kobuki_node:(AKA mobile base) is actually a nodelet, which wraps the C++ driverfor communicating with Kobuki

• cmd_vel_mux:is a velocity command multiplexer (or in otherwords a switch). Itmanages multiple incoming velocity commands according to theconfigured priority.

• Kobuki controller: is a nodelet-based controller type - usedfor various applications; one example is thekobuki_safety_controller,which watches the bumper, cliff and wheel drop sensors and actsaccordingly. Use this to implement your own reactive controller (seethe next tutorial)

Furthermore, thereis an implementation of a velocity smoother:yocs_velocity_smoother.This tool is optional, but highly recommended to use. In case a nodepublishing velocity commands can't ensure their smoothness, put thissmoother in between thatnode and the cmd_vel_mux.

一直纠结于这句话，其中thatnode被我误解，我把cmd_vel_mux放在了keyop(key_cmd_vel)／joyop(joy_cmd_vel)／navigation(cmd_vel)下面，velocity_smoother(cmd_vel_smooth)前面，怎么样都觉得不对劲，就修改了velocity_smoother的节点源码，利用cmd_vel_mux输出的active来判别是导航还是远程控制，回看了下资料，才发现我把顺序搞反了。

                                        

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emai:  [email protected]