Robotiq gripper control

[nitish3693]

Hi @vimior ,

Could you please suggest the steps to control Robotiq hand-e gripper using the ROS.

Could the gripper_move service be used ?

If the Tool Modbus communication method is needed. Could you please suggest what the uint8(unsigned char) data array in the service set_tool_modbus format is ?

How would we send the open and close or a particular position commands using the service set_tool_modbus ?

[vimior]

@nitish3693

1. You cannot use gripper_move to control robotiq, this can only control xarm_gripper
2. Control robotiq can refer to the following steps
   • Use the set_tgpio_modbus_baudrate service to set the baud rate to 115200
   • Use getset_tgpio_modbus_data to control robotiq, and the sent data refers to the robotiq protocol, here is an example
   • Reset:
   • send_data: 0x09, 0x10, 0x03, 0xE8, 0x00, 0x03, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
   • respond_len: 6
   • Activate:
   • send_data: 0x09, 0x10, 0x03, 0xE8, 0x00, 0x03, 0x06, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00
   • respond_len: 6
   • Set_Pos:
   • send_data: 0x09, 0x10, 0x03, 0xE8, 0x00, 0x03, 0x06, 0x09, 0x00, 0x00, pos, speed(0xFF), force(0xFF)
   • respond_len: 6
   • Close:
   • send_data: 0x09, 0x10, 0x03, 0xE8, 0x00, 0x03, 0x06, 0x09, 0x00, 0x00, 0xFF, speed(0xFF), force(0xFF)
   • respond_len: 6
   • Open:
   • send_data: 0x09, 0x10, 0x03, 0xE8, 0x00, 0x03, 0x06, 0x09, 0x00, 0x00, 0x00, speed(0xFF), force(0xFF)
   • respond_len: 6

[nitish3693]

Hi @vimior thanks for the suggestion, however i was not able to find the service set_tgpio_modbus_baudrate in the active service list when using the xarm. PFB the document containing the list of active services:

servicelist.txt

rosservice call /xarm/config_tool_modbus "baud_rate: 115200
timeout_ms: 20" 
message: "set_modbus_baudrate, ret=0 | set_modbus_timeout, ret=0"
ret: 0

and then tried the activate/reset services which causes the xArm to go into error state C33

rosservice call /xarm/getset_tgpio_modbus_data "{send_data: '0x09, 0x10, 0x03, 0xE8, 0x00, 0x03, 0x06, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00', respond_len: 6, host_id: 0, is_transparent_transmission: false, use_503_port: false}" 
ret: 20

[vimior]

@nitish3693 Sorry, I forgot there is a host_id parameter, the value should be 9

[nitish3693]

Thanks @vimior for the suggestion I will test that. Should i use the service config_tool_modubus in place of set_tgpio_modbus_baudrate

[vimior]

@nitish3693 Yes.

[nitish3693]

Hi @vimior thanks for your suggestion earlier. We conducted a test today with suggested host_id, PFB the service call and responses :

rosservice call /xarm/config_tool_modbus 115200 20
message: "set_modbus_baudrate, ret=0 | set_modbus_timeout, ret=0"
ret: 0

rosservice call /xarm/get_tgpio_modbus_baudrate 
data: 115200
ret: 0

rosservice call /xarm/getset_tgpio_modbus_data "{send_data: '0x09,0x10,0x03,0xE8,ox00,0x03,0x06,0x01,0x00,0x00,0x00,0x00,0x00', respond_len: 6, host_id: 9, is_transparent_transmission: false, use_503_port: false}" 
ret: 0
message: ''
respond_data: [0, 0, 0, 0, 0, 0]

The getset_tgpio_modbus_data service call returned with the value 0 but it caused the,

[ERROR] [1690962446.850880161]: [ns: /xarm/] Controller Error detected! C33: [ Controller GPIO Error ]

Please not we are using the Hand-E gripper connected using the instruction in : http://help.ufactory.cc/en/articles/3997200-guide-to-use-the-robotiq-gripper-on-ufactory-xarm

The settings used in the xArm studio : xArmSetup.docx

We are able to open and close the gripper using the blockly program :

[vimior]

@nitish3693 Is this a typo? We don't have this mechanical claw on hand now, so we can't judge the problem very well, so I hope you can reproduce it again, and then download the log from the studio immediately and provide it to us, so that we can troubleshoot the problem. Studio -> Settings -> System -> Log -> Download

[nitish3693]

Hi @vimior that was the typo here.

Replicating the issue again :

nitish@nitish:~$ rosservice call /xarm/config_tool_modbus "baud_rate: 115200
timeout_ms: 20" 
message: "set_modbus_baudrate, ret=0 | set_modbus_timeout, ret=0"
ret: 0
nitish@nitish:~$ rosservice call /xarm/get_tgpio_modbus_baudrate 
data: 115200
ret: 0
message: "ret = 0, current baud_rate = 115200"
nitish@nitish:~$ rosservice call /xarm/getset_tgpio_modbus_data "{send_data: '0x09, 0x10, 0x03, 0xE8, 0x00, 0x03, 0x06, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00', respond_len: 6, host_id: 9, is_transparent_transmission: false, use_503_port: false}" 
ret: 0
message: ''
respond_data: [0, 0, 0, 0, 0, 0]

Log files are here :

XI130412C23L34_2023-08-03_09-32-55.tar.gz

[penglongxiang]

Hi @nitish3693, please try this command instead: $ rosservice call /xarm/getset_tgpio_modbus_data "{send_data: [0x09, 0x10, 0x03, 0xE8, 0x00, 0x03, 0x06, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00], respond_len: 6, host_id: 9, is_transparent_transmission: false, use_503_port: false}"

Instead of ' ', use [ ] to enclose the data.

[nitish3693]

Hi @penglongxiang thanks for your suggestion. The services are now working without the errors.

[penglongxiang]

@nitish3693 Glad to know it works, the previous way may interpret the content inside ' ' as ASCII characters but not hex values.

[nitish3693]

Hi @penglongxiang @vimior could this service getset_tgpio_modbus_data operate at 50Hz command frequency ?

When this service is used at 50 Hz the indicator light in the gripper goes continuous blue showing it is receiving commands but the gripper stops responding to changes in the position of the finger.

Could it be because the service is getting clogged with the requests and then does not function properly ?

[vimior]

@nitish3693 Is the 50HZ command to control the opening and closing of the robotiq? For your use, the getset_tgpio_modbus_data interface forwards the command to the robotiq. The interface itself does not limit the frequency. As for how to execute it, it depends on the logic of the robotiq, but I I think there is a problem if 50HZ has been controlling the opening and closing.

[nitish3693]

Hi @vimior yeah 50Hz is the frequency we want to use to call the service to send different positions of the gripper.

[vimior]

@nitish3693 With a frequency of 50HZ, robotiq may not have completed the last action. I don’t know the logic of robotiq receiving a new action before completing the previous action.

[nitish3693]

Thanks @vimior @penglongxiang for the support.

[nitish3693]

The issue with the control at 50Hz was with the buffering in the commands. Due to the buffer the commands were not updating and old commands were being transmitted to Gripper.

Solved by limiting the buffer size of the command topic.