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Splash Forums Development SDK Gripper control does not work

This topic contains 6 replies, has 2 voices, and was last updated by  Alex 1 year, 5 months ago.

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  • #2554



    I am working on Windows to control Jaco2 arm, and the gripper control is not working.

    I tried both ways as below, but nothing works. Any suggestions?
    (It works with the GUI DevelopmentCenter, but not with the SDK code).

    pointToSend.Position.Type = ANGULAR_POSITION;


    pointToSend.Position.Actuators.Actuator1 = currentAngle.Actuators.Actuator1;
    pointToSend.Position.Actuators.Actuator2 = currentAngle.Actuators.Actuator2;
    pointToSend.Position.Actuators.Actuator3 = currentAngle.Actuators.Actuator3;
    pointToSend.Position.Actuators.Actuator4 = currentAngle.Actuators.Actuator4;
    pointToSend.Position.Actuators.Actuator5 = currentAngle.Actuators.Actuator5;
    pointToSend.Position.Actuators.Actuator6 = currentAngle.Actuators.Actuator6;

    pointToSend.Position.Fingers.Finger1 = (float)deg;//deg value given before; I tried different values such as 0, 45.0, 6500.0
    pointToSend.Position.Fingers.Finger2 = (float)deg;
    pointToSend.Position.Fingers.Finger3 = (float)deg;

    SendBasicTrajectory(pointToSend); //SendAdvanceTrajectory does not work, and even crashes the program

    /// Trial2
    pointToSend.Position.Type = ANGULAR_VELOCITY;


    pointToSend.Position.Actuators.Actuator1 = 1;
    pointToSend.Position.Actuators.Actuator2 = 0;
    pointToSend.Position.Actuators.Actuator3 = 0;
    pointToSend.Position.Actuators.Actuator4 = 0;
    pointToSend.Position.Actuators.Actuator5 = 0;
    pointToSend.Position.Actuators.Actuator6 = 1;

    pointToSend.Position.Fingers.Finger1 = (float)deg;//deg value given before; I tried different values such as 0, 45.0, 6500.0
    pointToSend.Position.Fingers.Finger2 = (float)deg;
    pointToSend.Position.Fingers.Finger3 = (float)deg;

    for (int i = 0; i < 500; i++)
    SendBasicTrajectory(pointToSend);//SendAdvanceTrajectory does not work, and even crashes the program
    // This code makes the arm move a bit (due to 1deg incrementals on Joint1 and Joint6, but the gripper does not move at all.



    Dear Chpark,

    Before being able to control the gripper, you will need to initialize the fingers first. Have you been able to do that?

    If you refer to the SDK Offline documentation (in the JACO2SDK installation folder), you should find the information to initialize the fingers with the function InitFingers

    Please keep us posted if that works!




    Hi Alex,

    Yes, I did InitFingers().

    What I was curious was that if the SendBasicTrajectory() command also sends finger control commands, or if I need to use SendAdvanceTrajectory()
    to send fingers control.

    It seems the Windows version API does not have the SendAdvanceTrajectory command compiled in it.

    Two more issues came up after my posting:

    1. I have two JACO2 arms connected to one PC. One Jaco2 arm stopped working last week, and I see yellow lights blinking on the LAB port of the arm base. How should I fix it? The arm is not recognized when connected to the PC via USB port.

    2. I notice version differences between the header and dll files in the API folder with the same files in the Kinova_example folders. It seems the files in the API folders (dated 2014) are about 1 year older than those in the example folder (dated 2015). The sizes of the dll files are also different.
    So which version should I link and include in my own project?



    LAB port => LAN port. Typo.

    • This reply was modified 1 year, 5 months ago by  chpark.


    Problem with the gripper control solved, but not the dead JACO2 arm issue.

    The issue with the gripper control was that I was switching between Cartesian control and Angular control, and I learned that
    I need to InitStruct() the pointToSend structure when I make the change.

    However, the dead arm is still not respoinding, and it is not recognized at all from my PC. Is there any easy fix?
    The yellow light on the LAN port of the JACO2 arm blinks occasionally.
    It powers up and maintains torque on the joints, but nothing else.



    I also noticed that if I connect the joystick controller and turn on the arm, the green lights on the joystick keeps blinking and never stops to a steady ON state. Does this mean the power controller circuit may be short-circuited, or may there be an easy fix?



    Dear chpark

    We are glad you have been able to solve the gripper problem on your end! Thanks for letting us know aswell how you have been able to solve it.

    About the problem with one of the arm, can you please write us an email at support@kinova.ca with the serial number of the problematic arm? We will be able to solve the problem this way and also record it in our system.

    Thank you very much,

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