RG2 gripper Keeps on Falling from Jaco Arm

Typically: "How do I... ", "How can I... " questions
Post Reply
alix
Posts: 44
Joined: 17 Sep 2019, 14:48

RG2 gripper Keeps on Falling from Jaco Arm

Post by alix » 26 Nov 2019, 11:51

Hi,
I am working with Jaco, trying to attach RG2 gripper to it, but it keeps on falling as the simulations start. If I make it static then it behaves oddly and the warning comes regarding a static object over the dynamic structure. But if I make RG2 dynamic it falls down.
Help me please !!!!

coppelia
Site Admin
Posts: 7450
Joined: 14 Dec 2012, 00:25

Re: RG2 gripper Keeps on Falling from Jaco Arm

Post by coppelia » 27 Nov 2019, 14:48

Hello,

do you have a force/torque sensor between the Jaco end-effector and the RG2 gripper?

Cheers

alix
Posts: 44
Joined: 17 Sep 2019, 14:48

Re: RG2 gripper Keeps on Falling from Jaco Arm

Post by alix » 27 Nov 2019, 16:30

coppelia wrote:
27 Nov 2019, 14:48
Hello,

do you have a force/torque sensor between the Jaco end-effector and the RG2 gripper?

Cheers
Yes, I have force sensor, as here you can see in this screenshot https://ibb.co/j8WGJT6

alix
Posts: 44
Joined: 17 Sep 2019, 14:48

Re: RG2 gripper Keeps on Falling from Jaco Arm

Post by alix » 27 Nov 2019, 17:10

coppelia wrote:
27 Nov 2019, 14:48
Hello,

do you have a force/torque sensor between the Jaco end-effector and the RG2 gripper?

Cheers
Hi Coppelia,
Can you also please tell me that can we make the opening and closing of RG2 gripper slower?

coppelia
Site Admin
Posts: 7450
Joined: 14 Dec 2012, 00:25

Re: RG2 gripper Keeps on Falling from Jaco Arm

Post by coppelia » 27 Nov 2019, 20:08

From the picture it looks ok. But it is just a picture. Please post the scene.
To make the gripper open/close slower/faster, adjust the variable motorVelocity in the child script attached to the gripper base.

Cheers

alix
Posts: 44
Joined: 17 Sep 2019, 14:48

Re: RG2 gripper Keeps on Falling from Jaco Arm

Post by alix » 28 Nov 2019, 11:30

coppelia wrote:
27 Nov 2019, 20:08
From the picture it looks ok. But it is just a picture. Please post the scene.
To make the gripper open/close slower/faster, adjust the variable motorVelocity in the child script attached to the gripper base.

Cheers
Hi Coppelia,
Bundle of thanks for the help, it got resolved when I made the IKTip child of the RG2 gripper. I was unable to understand the logic, but it worked.
I have another question, I'll highly appreciate if you can help me, please. Like we have the scene "MotionPlanningandGrasping.ttt", in which Jaco arms reaches the target using OMPL. I want to know that suppose the Jaco is reaching the glass from left side in the scene, if I want to make it to reach same target but from right, or suppose from upside, from where in the code this can be modified or controlled? Does it have to do something with that Shift Operation?

coppelia
Site Admin
Posts: 7450
Joined: 14 Dec 2012, 00:25

Re: RG2 gripper Keeps on Falling from Jaco Arm

Post by coppelia » 02 Dec 2019, 10:08

I guess there are many ways to implement this. How this was implemented in the scene you mention is following:
  • First, we try to reach an approach pose. This is typically a couple of centimeters away from the goal pose. This is handled via path planning functions. That approach pose is normally specified via a dummy's position and orientation. So changing that dummy's position and orientation will also change the approach pose.
  • Next, we move in a straight line from the approach pose to the goal pose. This in handled via IK functions. There also, the goal pose is specified via a dummy, or via an offset value from the approach pose.
Cheers

alix
Posts: 44
Joined: 17 Sep 2019, 14:48

Re: RG2 gripper Keeps on Falling from Jaco Arm

Post by alix » 02 Dec 2019, 15:49

coppelia wrote:
02 Dec 2019, 10:08
I guess there are many ways to implement this. How this was implemented in the scene you mention is following:
  • First, we try to reach an approach pose. This is typically a couple of centimeters away from the goal pose. This is handled via path planning functions. That approach pose is normally specified via a dummy's position and orientation. So changing that dummy's position and orientation will also change the approach pose.
  • Next, we move in a straight line from the approach pose to the goal pose. This in handled via IK functions. There also, the goal pose is specified via a dummy, or via an offset value from the approach pose.
Cheers
thanks a lot , i'll try it...

Post Reply