Gripper closing issue in Gen3 Lite

[GitNzino]

Description

When I try to execute the command example.example_send_gripper_command(gripper_close) with gipper_close = 1.0 the gripper only close to 50%

Version

ROS distribution : melodic

Branch and commit you are using : latest

Other Curiosity

It is possible to deactivate the protection via ros python as showed in the web app?

Thank you in advice and have a good day, Lorenzo

[felixmaisonneuve]

Hi @GitNzino.

Are you able to fully close the gripper (e.g. via the webapp)? I assume you are running the example_full_arm_movement, can you provide the full log output of your terminal console when you run it? The example sends 2 gripper command (1 to fully open the gripper and one to close it 50%). Are you sure this second command (in the example is removed or commented out)? Also, if you changed the c++ example, did you do a catkin_make to compile this new version of the example?

To deactivate the protection zone in ros, yes, it is possible. Every API call is mapped to a ROS service. What you will want to do is call the UpdateProtectionZone service and update your PtectionZone by putting the is_enabled parameter to false. This might require you to ReadAllProtectionZones first to find the exact one you want to edit.

Regards, Felix

[GitNzino]

Hi, thank you for response.

The gripper problem was about the time to reach the goal pose.

For the protection zone i added this function in example code code:

def protection_zone_mod(self,radius):
        protection_zone_service = '/' + self.robot_name + '/base/update_protection_zone'
        rospy.wait_for_service(protection_zone_service)
        self.protection_zone_service = rospy.ServiceProxy(protection_zone_service, ProtectionZone)
        protection_zone = ProtectionZone()
        protection_zone.shape.dimensions = [radius, 0.35]
        protection_zone.is_enabled = False
        print(protection_zone)
        self.protection_zone_service(protection_zone)

and this output:

process[my_gen3_lite/tablet_movement-1]: started with pid [9141]
[INFO] [1655394495.276525]: Using robot_name my_gen3_lite , robot has 6 degrees of freedom and is_gripper_present is True
Traceback (most recent call last):
  File "/home/lorenzo/cw_kinova/src/kinova/kortex_movement/scripts/tablet_movement.py", line 543, in <module>
    main()
  File "/home/lorenzo/cw_kinova/src/kinova/kortex_movement/scripts/tablet_movement.py", line 526, in main
    example.protection_zone_mod(0.08)
  File "/home/lorenzo/cw_kinova/src/kinova/kortex_movement/scripts/tablet_movement.py", line 124, in protection_zone_mod
    self.protection_zone_service = rospy.ServiceProxy(protection_zone_service, ProtectionZone)
  File "/opt/ros/melodic/lib/python2.7/dist-packages/rospy/impl/tcpros_service.py", line 411, in __init__
    super(ServiceProxy, self).__init__(name, service_class)
  File "/opt/ros/melodic/lib/python2.7/dist-packages/rospy/service.py", line 59, in __init__
    self.request_class = service_class._request_class
AttributeError: type object 'ProtectionZone' has no attribute '_request_class'
[my_gen3_lite/tablet_movement-1] process has died [pid 9141, exit code 1, cmd /home/lorenzo/cw_kinova/src/kinova/kortex_movement/scripts/tablet_movement.py __name:=tablet_movement __log:=/home/lorenzo/.ros/log/76c7a370-ed8b-11ec-8fb0-3c950922ab5a/my_gen3_lite-tablet_movement-1.log].
log file: /home/lorenzo/.ros/log/76c7a370-ed8b-11ec-8fb0-3c950922ab5a/my_gen3_lite-tablet_movement-1*.log

What could I do?

[felixmaisonneuve]

The protection_zone_service takes a request. Looking at other examples in the repo, I feel like you should do something like

from kortex_driver.srv import ProtectionZone, ProtectionZoneRequest # this is probably import * in your case so you don't have to worry about it

def protection_zone_mod(self,radius):
        protection_zone_service = '/' + self.robot_name + '/base/update_protection_zone'
        rospy.wait_for_service(protection_zone_service)
        self.protection_zone_service = rospy.ServiceProxy(protection_zone_service, ProtectionZone)
        protection_zone_request = ProtectionZoneRequest()
        protection_zone_request.input.shape.dimensions = [radius, 0.35]
        protection_zone_request.input.is_enabled = False
        print(protection_zone_request)
        self.protection_zone_service(protection_zone_request)

But even with that, I do not think it will update your protection zone because you probably need to specify the ProtectionZone handle so the arm knows which protection zone you are trying to update. This is why you might need to ReadAllProtectionZones, to find the handle of the protection zone your are trying to edit.

I cannot test it at the moment, if it doesn't work and you still have issues, I will be glad to help you Best, Felix

[GitNzino]

Hi,

Thank you very much for support

I tried your code but I notice this issues:

• The ProtectionZoneRequest() does not exist
• Trying to do the same things with other simila class like: UpdateProtectionZone() i cannot obtain the rigth interaction

What should i do?

Thank you in advice

[GitNzino]

Hi,

At least I solved in this manner:

        protection_zone_reader = '/' + self. robot_name + '/base/read_all_protection_zones'
        rospy.wait_for_service(protection_zone_reader)
        self.protection_zone_reader = rospy.ServiceProxy(protection_zone_reader, ReadAllProtectionZones)
        protection_zone_read = ReadAllProtectionZonesRequest()

        zone = self.protection_zone_reader(protection_zone_read)

        protection_zone_service = '/' + self.robot_name + '/base/update_protection_zone'
        rospy.wait_for_service(protection_zone_service)
        self.protection_zone_service = rospy.ServiceProxy(protection_zone_service, UpdateProtectionZone)

        send = UpdateProtectionZoneRequest(zone.output.protection_zones[0])     

        send.input.shape.dimensions = [0.35, radius]
        send.input.is_enabled = True

        self.protection_zone_service(send)   

Do you think is it right?

[felixmaisonneuve]

Yes this is actually what it should look like.

Does this work? When changing send.input.is_enabled = True to send.input.is_enabled = False, does the protection de-activate in the web app?

[GitNzino]

Yes, it does! Also when the area is resized also in the web app appears.

[felixmaisonneuve]

Nice, It that case, I will close this issue.

Please re-open the issue or leave a comment if you experience nother problem.

Regards, Felix