Search found 46 matches

by Adrian Lai
Mon Apr 08, 2019 10:29 am
Forum: A musculoskeletal model for movements that involve high hip and knee flexion
Topic: A musculoskeletal model for movements that involve high hip and knee flexion Public Forum
Replies: 2
Views: 1144

Re: A musculoskeletal model for movements that involve high hip and knee flexion Public Forum

Hi Saylee, I would use the task, constraints and actuator files from this project as a start to run RRA and CMC (https://simtk.org/frs/?group_id=773). All the bodies and degrees of freedom should be identical so they should work. Then from there, you can tweak the files to suit your purpose. Good lu...
by Adrian Lai
Thu Nov 08, 2018 10:24 am
Forum: OpenSim
Topic: Defining two custom joints for a body
Replies: 3
Views: 658

Re: Defining two custom joints for a body

I've come across this problem in the past and I used either a weld or point constraint to connect two bodies that have already been assigned joints.

Good luck!

ADrian
by Adrian Lai
Thu Sep 06, 2018 1:48 pm
Forum: OpenSim
Topic: Sprint running pelvis residuals
Replies: 3
Views: 1176

Re: Sprint running pelvis residuals

I checked through my steps and the odd behaviour of tX seemed to disappear once I filtered the IK output at 8 Hz using the built in OpenSim filter (see Figure 1). I was filtering the data at 4 Hz... likely too low! The data from the first figure is of purely the flight phase, but I still have very ...
by Adrian Lai
Tue Sep 04, 2018 10:16 am
Forum: OpenSim
Topic: Sprint running pelvis residuals
Replies: 3
Views: 1176

Re: Sprint running pelvis residuals

Hi Nicos, I have a few things you can check to see if it helps. You should check your filtering techniques of your inverse kinematics (i.e. joint angles) and particularly your ground reaction forces. If you're using a standard Butterworth filter with low cut-off frequencies, you're likely to get ove...
by Adrian Lai
Wed Jun 27, 2018 12:24 pm
Forum: OpenSim
Topic: Unising Matlab with OpenSim API in High Performance Computing clusters
Replies: 12
Views: 2145

Re: Unising Matlab with OpenSim API in High Performance Computing clusters

Hi Tom and Chris, I might be able to help here. When I've run parfor in MATLAB with the OpenSim API, a new instant of the model was needed for each loop iteration (see the code below). It means that each thread must have a unique model in which to use rather than one that has been previously initial...
by Adrian Lai
Thu Jun 07, 2018 9:27 am
Forum: OpenSim
Topic: Obtaining reaction forces
Replies: 13
Views: 2965

Re: Obtaining reaction forces

Ahh sorry for the misunderstanding Tom. I missed the part where the count started at 0 so I was only initialising the size of my rForce and rTorque to either model.getBodySet().getSize()-1 or model.getJointSet().getSize(), which both caused the error. Perfect! Thanks for working me through to a solu...
by Adrian Lai
Wed Jun 06, 2018 5:52 pm
Forum: OpenSim
Topic: Obtaining reaction forces
Replies: 13
Views: 2965

Re: Obtaining reaction forces

Hi Tom, Thanks for the information. From the test code I sent earlier, using your function, I can obtain rForces and rTorques that equal to the number of joints in my model (I'm running OpenSim 3.3). It works fine when I run the code the first time around. However, when I re-run the code or re-open ...
by Adrian Lai
Wed Jun 06, 2018 10:58 am
Forum: OpenSim
Topic: Obtaining reaction forces
Replies: 13
Views: 2965

Re: Obtaining reaction forces

Thanks for the function Tom. It works and I can get reaction forces at all the joints. However, I'm not sure if it's due to my computers (I've tried it on two computer so far), but after running the function once, the second time I run osimModel.getSimbodyEngine().computeReactions(osimState,rForce,r...
by Adrian Lai
Tue Jun 05, 2018 4:03 pm
Forum: OpenSim
Topic: Obtaining reaction forces
Replies: 13
Views: 2965

Re: Obtaining reaction forces

Hi Chris and Tom, I've tried the following code but my MATLAB crashes. Can you point me in the right direction? import org.opensim.modeling.* model_name = 'test_model.osim'; osimModel = Model(model_name); osimState = osimModel.initSystem(); no_joints = osimModel.getJointSet.getSize(); temp_vector = ...
by Adrian Lai
Mon Jun 04, 2018 1:11 pm
Forum: OpenSim
Topic: Obtaining reaction forces
Replies: 13
Views: 2965

Re: Obtaining reaction forces

Thanks Tom! I'll let you know how it goes.