mc_embodied_kit_ros

MC Embodied Intelligence Suit ROS Package

Packages

• tracer_base: a ROS wrapper around tracer SDK to monitor and control the robot
• tracer_bringup: launch and configuration files to start ROS nodes
• tracer_msgs: tracer related message definitions

Communication interface setup

Please refer to the README of "ugv_sdk" package for setup of communication interfaces.

Note on CAN interface on Nvidia Jetson Platforms

Nvidia Jeston TX2/Xavier/XavierNX have CAN controller(s) integrated in the main SOC. If you're using a dev kit, you need to add a CAN transceiver for proper CAN communication.

Basic usage of the ROS package

1. Install dependent packages

   $ sudo apt-get update
   $ sudo apt-get install build-essential git cmake libasio-dev
   $ sudo apt install ros-noetic-joint-state-publisher-gui
   $ sudo apt install ros-noetic-ros-controllers
   $ sudo apt install ros-noetic-gmapping
   $ sudo apt install ros-noetic-map-server
   $ sudo apt install ros-noetic-navigation
   

2. Clone the packages into your catkin workspace and compile

   (the following instructions assume your catkin workspace is at: ~/catkin_ws/src)

   $ cd ~/catkin_ws/src
   $ git clone https://github.com/elephantrobotics/mc_embodied_kit_ros.git
   $ cd ..
   $ catkin_make
   

3. Setup CAN-To-USB adapter

• Enable gs_usb kernel module(If you have already added this module, you do not need to add it)

  $ sudo modprobe gs_usb
  

• first time use tracer-ros package

  $rosrun tracer_bringup setup_can2usb.bash
  

• If not the first time use tracer-ros package(Run this command every time you turn on the power)

  $rosrun tracer_bringup bringup_can2usb.bash
  

4. Launch ROS nodes

• Start the base node for the real robot whith can

  $ roslaunch tracer_bringup tracer_robot_base.launch
  

• Start the keyboard tele-op node

  $ roslaunch tracer_bringup tracer_teleop_keyboard.launch
  

• If the can-to-usb has been connected to the TRACER robot and the car has been turned on, use the following command to monitor the data from the TRACER chassis

  candump can0
  

Python interface usage of ROS package

Prerequisites for use

• 终端切换到目标目录之后，输入 python 指令：

  $ cd ~/catkin_ws/src/mc_embodied_kit_ros/tracer_bringup/scripts
  $ python
  

• 在python的交互式环境导入底盘控制的接口库

  from chassis_controller import ChassisController
  

• 简单使用

  # 示例
  from chassis_controller import ChassisController
  
  cc = ChassisController()
  
  # 前进、后退
  cc.move_forward(1.0, 2)  # 前进 2 秒, 速度为 1 m/s
  cc.move_backward(-1, 2)  # 后退 2 秒, 速度为 -1 m/s
  # 停止小车
  cc.stop()
  

Python API使用说明

1 move_forward(speed, duration)

• function: Move forward

• Parameters:

  • speed: forward speed (0.0 ~ 1.8 m/s).
  • duration: duration (positive number, in seconds).

2 move_backward(speed, duration)

• function: Move forward

• Parameters:

  • speed: backward speed (-1.8 ~ 0 m/s).
  • duration: duration (positive number, in seconds).

3 turn_left(speed, duration)

• function: turn left rotation

• Parameters:

  • speed: move speed (0.0 ~ 1.8 m/s).
  • duration: duration (positive number, in seconds).

4 turn_right(speed, duration)

• function: turn right rotation

• Parameters:

  • speed: backward speed (-1.8 ~ 0 m/s).
  • duration: duration (positive number, in seconds).

5 stop(speed, duration)

• function: Stop Move

tracer底盘导航实现

雷达建图 - Gmapping

1. 开启底盘节点和雷达通信

   roslaunch tracer_odometry tracer_active.launch
   

   注意： 启动底盘节点前需确保CAN总线已经使能，系统重启或者重新拔插CAN总线，都需要执行使能指令： rosrun tracer_bringup setup_can2usb.bash

2. 打开gmapping - 建图launch文件

   roslaunch tracer_navigation mapping.launch
   

3. 打开键盘控制文件

   roslaunch tracer_bringup tracer_teleop_keyboard.launch
   

4. 开始建图

   现在底盘小车可以在键盘控制下移动。同时，您可以在 Rviz 空间中观察到，随着小车的移动，我们的地图也在逐渐构建。

   注意：使用键盘操作小车时，请确保运行 tracer_teleop_keyboard.launch 文件的终端是当前选定的终端；否则，键盘控制程序将无法识别按键。此外，为了获得更好的映射效果，建议在键盘控制时将线速度设为 0.2，角速度设为 0.4，因为较低的速度往往会产生更好的映射效果。

5. 保存构建的地图

   打开另一个新的终端控制台，在命令行中输入以下命令，保存 tracer 扫描的地图：

   cd ~/catkin_ws/src/mc_mebodied_kit_ros/tracer_navigation/map
   
   rosrun map_server map_saver
   

   执行成功后，将在当前路径(~/catkin_ws/src/mc_mebodied_kit_ros/tracer_navigation/map)下生成两个默认地图参数文件，即map.pgm和map.yaml。

地图导航

在此之前，我们已经成功创建了空间地图，并获得了一组地图文件，即位于 ~/catkin_ws/src/mc_mebodied_kit_ros/tracer_navigation/map 目录下的 map.pgm 和 map.yaml。

1. 开启底盘节点和雷达通信

   roslaunch tracer_odometry tracer_active.launch
   

2. 运行导航launch文件

   roslaunch tracer_navigation navigation_active.launch
   

SAFETY PRECAUSION:

Always have your remote controller ready to take over the control whenever necessary.