UArmForROS

This is the uarm ROS package designed by Joey Song ( [email protected] / [email protected])

0. Quickstart and Execution

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Three ways to control uArm movements

1. Installation

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1.1 Pre-Requirements

Connect uArm and get USB permission to access uArm

$ cd /etc/udev/rules.d

Creat a file ttyUSB.rules and put the following line: KERNEL=="ttyUSB*", MODE="0666". Save the file and reconnect uArm USB to make it effective. (if you already have the permission to access USB, you can skip this step)

If your uArm is connected to ttyACM instead of ttyUSB (you can check using dmesg -c command after connecting your uArm), Creat a file ttyACM.rules and put the following line: KERNEL=="ttyACM*", MODE="0666". Save the file and reconnect uArm USB to make it effective. (if you already have the permission to access USB, you can skip this step)

For using this package, the pyUarm library SHOULD be installed at first.

$ pip install pyuarm

And check your uArms's VID:PID using lsusb after connecting uArm.

$ lsusb
Bus 001 Device 020: ID 1234:1234 Arduino SA Mega 2560 R3 (CDC ACM)

And you need to specify your device number by editing this file e.g. if you prefer nano as an editor)

$ sudo nano /usr/local/lib/python2.7/dist-packages/pyuarm/tools/list_uarms.py

In this file, you need to change this line, VID:PID with your own device.

UARM_HWID_KEYWORD = "USB VID:PID=1234:1234"

Connect uArm to computer and upgrade your uArmProtocol Firmware

$ uarm-firmware -u

or

$ python -m pyuarm.tools.firmware -d

1.2 Package Download and Install

Install ros package in your src folder of your Catkin workspace.

$ cd ~/catkin_ws/src
$ git clone https://github.com/uArm-Developer/UArmForROS.git
$ cd ~/catkin_ws
$ catkin_make

2. Source FIles

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Before you use any packages in uarmForROS, source all setup.bash files which allow you to access uarm package

# System configure ROS environment variables automatically every time you open a shall
echo "source /opt/ros/[ROS_version]/setup.bash" >> ~/.bashrc
# For example, if you are using kinetic version of ROS
echo "source /opt/ros/kinetic/setup.bash" >> ~/.bashrc

# Source setup.bash
echo "source ~/catkin_ws/devel/setup.bash" >> ~/.bashrc
source ~/.bashrc

3. Package Modules

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3.1 Nodes

• uarm_core.py is the main node. Run this node before anything else. This node has two main modes: Control-Mode and Monitor-Mode. Control-Mode is used to control uarm directly in this node. Monitor-mode is to subscrib/listen to all topics which can be used to control uarm through these nodes. This node will automatically load Control-Mode first.

  Step 1: Connect uArm

  Set up ROS enviroment at first

  roscore

  Open another shall to connect uArm before use.

  rosrun uarm uarm_core.py connect  // this will find uarm automatically

  Step 2: Control-Mode

  Once connect uArm, you can use commands to control. Input h to see all the commands

  # For example: attach uarm (use at in short for attach)
  Input Commands (Input h to see all commands):  attach # or at
  # For example: read current x,y,z (use cc in short for currentCoords)
  Input Commands (Input h to see all commands):  currentCoords # or cc
  # For example: move uarm x,y,z (use mt in short for moveTo)
  Input Commands (Input h to see all commands):  moveTo 12 -12 12

  Input l to exit control-mode and get into Monitor mode

  Step 3: Monitor-Mode

  If you get the information as below, you can use both Topics-Pub and other ROS Nodes to control uarm through ROS.

  Begin monitor mode - listening to all fucntional topics
  =======================================================
           Use rqt_graph to check the connection         
  =======================================================

• uarm_status_node.py is the node which can control the attach-status or detach-status of uArm.

  Open another shall, and use this node in the monitor-mode of uarm_core.py node

  # attach uarm
  rosrun uarm uarm_status_node.py attach
  # detach uarm
  rosrun uarm uarm_status_node.py detach

• pump_node.py is the node which can control the pump on or off.

  Use this node in the monitor-mode of uarm_core.py node

  # pump on
  rosrun uarm pump_node.py on
  # pump off
  rosrun uarm pump_node.py off

• report_angles_node.py is the node which will report current angles.

  Use this node in the monitor-mode of uarm_core.py node

  # report once
  rosrun uarm report_angles_node.py
  # report 10 times
  rosrun uarm report_angles_node.py 10
  # report 10 times per 2 time_sec
  rosrun uarm report_angles_node.py 10 2

• report_coords_node.py is the node which will report current coords.

  Use this node in the monitor-mode of uarm_core.py node

  # report once
  rosrun uarm report_coords_node.py
  # report 10 times
  rosrun uarm report_coords_node.py 10
  # report 10 times per 2 time_sec
  rosrun uarm report_coords_node.py 10 2

• report_stopper_node.py is the node which will report stoppper status.

  Use this node in the monitor-mode of uarm_core.py node

  # report once
  rosrun uarm report_stopper_node.py
  # report 10 times
  rosrun uarm report_stopper_node.py 10
  # report 10 times per 2 time_sec
  rosrun uarm report_stopper_node.py 10 2

• write_angles_node.py is the node which will control 4 servo angles.

  Use this node in the monitor-mode of uarm_core.py node

  # write 4 servo angles
  rosrun uarm write_angles_node.py 90 50 50 10

• move_to_node.py is the node which will move to x,y,z position.

  Use this node in the monitor-mode of uarm_core.py node

  # move to x,y,z
  rosrun uarm move_to_node.py 12 -12 12
  # move to x,y,z,time (point 12 -12 12 in 2 seconds)
  rosrun uarm move_to_node.py 12 -12 12 2
  # move to x,y,z,time,servo_4 angle (servo_4 angle is 54)
  rosrun uarm move_to_node.py 12 -12 12 2 54

3.2 Topics

• uarm_status - control uarm status.

  Message_type: `std_msgs/String`.
  Data: attach / detach
  

• pump_control - control pump on or off.

  Message_type: `std_msgs/UInt8`.
  Data: 1 / 0
  

• pump_str_control - control pump on or off.

  Message_type: `std_msgs/String`.
  Data: high / low
  

• read_coords - report coords. Coords will also be written in parameters

  Message_type: `std_msgs/Int32`.
  Data: int (read times).
  Set-param: 'current_x' 'current_y' 'current_z' ('write in ros-parameter and can be invoked')
  

• read_angles - report angles. Angles will also be written in parameters

  Message_type: `std_msgs/Int32`.
  Data: int (read times).
  Set-param: 's1' 's2' 's3' 's4' ('will be written in ros_parameter for 4 `servo_angles')
  

• stopper_status - report stopper status. Status will also be written in parameters

  Message_type: `std_msgs/Int32`.
  Data: int (read times).
  Set-param: 'stopper_status'
  

• write_angles - write 4 servo angles.

  Message_type: uarm/Angles
  Data: int int int int
  

• move_to - move to x,y,z position.

  Message_type: uarm/Coords
  Data: float float float
  

• move_to_time - move to with time.

  Message_type: uarm/CoordsWithTime
  Data: float float float int
  

• move_to_time_s4 - move to with time and servo_4 angle.

  Message_type: uarm/CoordsWithTS4
  Data: float float float int int
  

3.3 Messages

• uarm/Angles

  uint8: servo_1
  uint8: servo_2
  uint8: servo_3
  uint8: servo_4
  

• uarm/Angles

  float32: x
  float32: y
  float32: z
  

• uarm/Angles

  float32: x
  float32: y
  float32: z
  uint8: time
  

• uarm/Angles

  float32: x
  float32: y
  float32: z
  uint8: time
  uint8: servo_4
  

4. Visualization in RViz

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4.1 Functions

• Display -- display.launch: This function will display robot movement in realtime when you manually move uArm
• Control -- control.launch: This function will allow you control the end-effector movement in 3 DOF along x,y,z axis.

4.2 Launch and Run

-Step 1: Set up ROS enviroment in one shall

roscore

In the second shall, connect uArm and set the listen mode as shown above

rosrun uarm uarm_core.py connect  // connect uArm
l                                 // transfer to monitor mode

-Step 2: Launch

a) For visualization function, in the third shall, run

roslaunch uarm display.launch

b) Or for control function, in the third shall, run

roslaunch uarm control.launch

-Step 3: Display and control: Open rviz to view robot in the fourth shall

rosrun rviz rviz

For both functions, import robot model in "Displays" panel on the left:

Add -> RobotModel           // click "add" and choose "RobotModel"
set Cell Size -> 0.1        // change "Cell Size" to 0.1 in "Grid"
set Fixed Frame -> base     // change "Fixed Frame" to base in "Global Options"

a) For Display function, right now a robot will display in the main window

b) For Control function, stop Display function and set

Add -> InteractiveMarker                  // click "add" and choose "InteractiveMarkers"
Update Topic -> /uarm_controller/update   // change "Update topic" in "InteractiveMarkers"

Drag 3 pairs of arrows to control uArm along x, y, z axis.