Search found 22 matches

by John Chan
Sun Aug 28, 2022 8:04 pm
Forum: OpenSim
Topic: Unit of restlength when adding passive spring
Replies: 2
Views: 245

Re: Unit of restlength when adding passive spring

Thank you for your reply. Is it possible that the restlength to be larger than the optical muscle fibre length?
by John Chan
Wed Aug 24, 2022 6:16 am
Forum: OpenSim
Topic: Unit of restlength when adding passive spring
Replies: 2
Views: 245

Unit of restlength when adding passive spring

As described in https://simtk-confluence.stanford.edu:8443/display/OpenSim/Simulation-Based+Design+to+Reduce+Metabolic+Cost#SimulationBasedDesigntoReduceMetabolicCost-B.Createamodelwithabiarticularpathspring , these are the information needed when adding a passive spring to the model. name = 'Biarti...
by John Chan
Fri Aug 19, 2022 2:58 am
Forum: OpenSim
Topic: Equation for reserve actuator and static optimization
Replies: 2
Views: 346

Re: Equation for reserve actuator and static optimization

Thank you so much for your reply.
by John Chan
Wed Aug 03, 2022 8:34 pm
Forum: OpenSim
Topic: Equation for reserve actuator and static optimization
Replies: 2
Views: 346

Equation for reserve actuator and static optimization

https://simtk-confluence.stanford.edu:8443/display/OpenSim/Working+with+Static+Optimization From the link above, in Study 3, we can see how the optimal force of the reserve actuator affects the muscle activation and force while performing static optimization. May I know where I can view the mathema...
by John Chan
Wed Apr 20, 2022 9:37 pm
Forum: OpenSim
Topic: Metabolic rate
Replies: 0
Views: 159

Metabolic rate

I have three questions regarding the metabolic rate estimated with OpenSim metabolic probe. https://simtk-confluence.stanford.edu:8443/display/OpenSim/Simulation-Based+Design+to+Reduce+Metabolic+Cost From the documentation above, 1) We know that we can get the metabolic rate of each muscle when runn...
by John Chan
Sun Nov 14, 2021 8:15 pm
Forum: OpenSim
Topic: How to attach an external object to two bodies
Replies: 2
Views: 360

How to attach an external object to two bodies

As stated in the Subject section, I plan to add an external object to two bodies in a model. To be more specific, the model is holding a rod with both hands, hence the rod should be attached to both hands with two custom joints, I presume? So far I manage to attach one hand to the rod, but I am unab...
by John Chan
Sun Oct 24, 2021 6:54 pm
Forum: OpenSim
Topic: Can I perform scaling with IMU data
Replies: 0
Views: 121

Can I perform scaling with IMU data

I understand that scaling is a very important step while studying body motion. However, for activities outdoors where it is impossible to use MoCap and only IMU is possible, how can we still go through the scaling step with just IMU data?
by John Chan
Tue Oct 05, 2021 9:44 pm
Forum: OpenSim
Topic: How to compare EMG with activation obtained in SO
Replies: 0
Views: 142

How to compare EMG with activation obtained in SO

The activation obtained during the static optimisation ranges between 0 and 1. Is the activation already the normalized activation (activation normalized to the maximum activation)? When I am comparing the EMG with the simulated activation, I will normalize the EMG data, shall I also normalize the a...
by John Chan
Thu Sep 23, 2021 8:50 pm
Forum: OpenSim
Topic: Questions about Reserve actuators
Replies: 0
Views: 183

Questions about Reserve actuators

I have 2 questions regarding the reserve actuators: 1) When I am running the Static Optimisation on my model, I tried to append the model by adding some reserve actuators on them as mentioned in this link https://simtk-confluence.stanford.edu:8443/display/OpenSim/Working+with+Static+Optimization I c...
by John Chan
Mon Aug 09, 2021 11:54 pm
Forum: OpenSim
Topic: Spine bends during IK
Replies: 1
Views: 222

Spine bends during IK

I am using the model from https://simtk.org/projects/spine_ribcage

While performing IK on the model, the model shows weird motion on its spine (bending), as shown in Figure below.
weird.jpg
weird.jpg (67.6 KiB) Viewed 222 times
May I know how should I solve it? Any reason why it behaves like that?