How to Connect Joints

Typically: "How do I... ", "How can I... " questions
Post Reply
moha89
Posts: 2
Joined: 18 Aug 2019, 02:01

How to Connect Joints

Post by moha89 » 19 Aug 2019, 12:22

Hi,
I want to build a 2-DOF landing platform as shown below
https://drive.google.com/file/d/10Y2eGk ... sp=sharing
I started with 1-DOF and have a problem connecting the joints. Please see the scene below
https://drive.google.com/file/d/1HkR_EV ... sp=sharing
What I want is to control the position of the prismatic joint (PJ)to rotate the platform and the other joints to be free.
I used the loop closure configuration but could not get to work. Any help would be appreciated
Thank you,

coppelia
Site Admin
Posts: 7330
Joined: 14 Dec 2012, 00:25

Re: How to Connect Joints

Post by coppelia » 05 Sep 2019, 05:43

Hello,

sorry for the delay.
Your approach is generally correct. You only need to be very careful to not overconstrain your mechanism. In the scene you posted, you will need a spherical joint instead of the revolute RJ1.
Then, make sure to work with appropriate masses and inertias. Have a look at design considerations 7 & 8 on this page.
Also, switch from one engine to another from time to time, to see if that makes a difference.

Cheers

moha89
Posts: 2
Joined: 18 Aug 2019, 02:01

Re: How to Connect Joints

Post by moha89 » 11 Sep 2019, 15:51

Thanks for the reply! Everything is fine with landing platform now.
I have another question if you don't mind. I am trying connect V-REP to MATLAB through B0-based remote API and getting the following errors/warnings:

for simpleTest.m
Warning: The following error was caught while executing 'b0RemoteApi' class destructor:
The following error occurred converting from containers.Map to double:
Error using double
Conversion to double from containers.Map is not possible.
> In simpleTest at 43
Undefined variable client.

Error in simpleTest (line 66)
client.delete();

for testing.m
Warning: The following error was caught while executing 'b0RemoteApi' class destructor:
The following error occurred converting from containers.Map to double:
Error using double
Conversion to double from containers.Map is not possible.
> In testing at 6
Undefined function 'dumpmsgpack' for input arguments of type 'cell'.

Error in b0RemoteApi/handleFunction (line 297)
packedData = dumpmsgpack({{funcName,obj.clientId,topic,0},reqArgs});

Error in b0RemoteApi (line 136)
obj.handleFunction('inactivityTolerance',{obj.inactivityToleranceInSec},obj.serviceCallTopic);

Error in testing (line 6)
client=b0RemoteApi('b0RemoteApi_matlabClient','b0RemoteApi');

What to do to get rid of them?
P.S. I was able to connect V-REP to C++ through B0-based remote API, so I think I have all the required libraries.

Post Reply