Modelling of Robot contact with object

Question

Md Rakibul 2012-6-23

1
链接

此问题的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/41899-modelling-of-robot-contact-with-object

评论： TEJAS PHUTANE 2020-3-12

I am a PhD student working on multi fingered robot hand for grasping. For grasping issue, I need to model a contact between fingertip and stiff simple object with known location and geometry for measuring contact force. This can be done in simulink easily. I am trying to implement in Simmechanics. I already had a look at bouncing ball model. For example, I have 2 dof planar robot hand and a vertical wall model. I defined end link of robot and also defined wall with weld joint. Assume for simplicity that I will get force only in horizontal direction and also defined condition to get contact force. Now, do I need to put an extra degree of freedom between last link of robot body and object body? I am stucked at this point. If you have any option, I can send the file, too.

Your help will be appreciated. Thank you.

Rakibul Hasan

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

TEJAS PHUTANE 2020-3-12

Hi,I am using simscape contact force library to model a gripper to grab a ball,however while using sphere to plane force block,the ball bounces off the gripper. I think it has something to do with non linear contact force,I can't get any example for the same. please help.

请先登录，再进行评论。

请先登录，再回答此问题。

Answer 1

Guy Rouleau 2012-6-23

1
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/41899-modelling-of-robot-contact-with-object#answer_51596

You have 2 options:

1. You can model only the arm (no wall in SimMechanics). Use a Body sensor to get the pose of the EE in Simulink, then compute the contact forces/torques and apply them to the arm using a Body Actuator.

2. Connect a joint between the 2 parts (arm and wall). In your 2D example this would probably a planar. Then use a Joint sensor to measure the relative position of the 2 bodies. In Simulink, compute the contact forces/torques and apply back to the joint using a joint actuator.

This central submissions can give you an example of computing and applying contact forces with the ground:

http://www.mathworks.com/matlabcentral/fileexchange/21439-simulation-of-a-one-legged-hopping-robot

4 个评论
显示 2更早的评论隐藏 2更早的评论

K E 2012-6-27

I am curious: how did you stop the arm from crossing the wall?

Bahri SEKERCI 2015-12-10

Hi I have a very similar problem.

I have a human limbs. first of all I contacted human foot with ground. This is succesful. But when I worn robot foot, I can not contact with ground. Due to this problem, I can not measure that want to valuses(reaction forces) between human foot and robot foot.

How can I solve this problem.

Bahri.

请先登录，再进行评论。

Answer 2

jone 2014-2-23

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/41899-modelling-of-robot-contact-with-object#answer_125730

Hi Guys I have very similar problem and I hope to get help If I have two bodies and first one moves to impact with second one is there any way to know when the impact happens and after that how to calculate contact force (Fx,Fy,Fz) additional details : I don't know real position of second bodies because its may translate and rotate between specified rang

thank you

0 个评论
显示 -2更早的评论隐藏 -2更早的评论

请先登录，再进行评论。

Answer 3

Erick Oberstar 2014-7-8

0
链接

此回答的直接链接

https://ww2.mathworks.cn/matlabcentral/answers/41899-modelling-of-robot-contact-with-object#answer_144182

I'm working on a compliant contact problem similar to this and the models outlined here may provide some insight. http://www.araa.asn.au/acra/acra2009/papers/pap125s1.pdf My problem is how to dynamically wire in the compliance force once the contact is detected. I am attempting to do this with a conditional path gated by if block wired into an action subsystem. However the model doesn't seem to like this as I get a simulink error:

Input data dependency violation due to action subsystems. See Subsystem Examples in the Simulink library for valid and invalid examples of action subsystems Component: Simulink | Category: Model error

The Action subsystem is just a input port wired to an output port.

1 个评论
显示 -1更早的评论隐藏 -1更早的评论

Bahri SEKERCI 2015-12-10

Hi I have a very similar problem.

I have a human limbs. first of all I contacted human foot with ground. This is succesful. But when I worn robot foot, I can not contact with ground. Due to this problem, I can not measure that want to valuses(reaction forces) between human foot and robot foot.

How can I solve this problem.

Bahri.

请先登录，再进行评论。