GRF prediction

Main Forum
1

Dear AnyBody,

I wonder what are the differences in parameters defined in ForcePlate.any and GRF_example.any? In ForcePlate.any, we need to fine tune the height settings and velocity threshold, then we need to adjust LimitDistLow, LimitDistHigh, and LimitVelHigh in GRF_example.any. What are functions of those parameters? and why they have to be defined in two separate files?

Thanks!
-Phoebe

2

Hi Phoebe,

I am assuming that you’re talking about the GRF prediction algorithm.

To understand the parameters, first note that when you define a predictive force plate, you define (a) a base frame for your force plate, (b) segment on which the contact nodes are created and © Normal direction for the force plate. The force plate is by default a cylinder whose origin coincides with the plate frame and whose long axis is along the normal direction:

a. LimitDistLow and LimitDistHigh: lower and upper points of the cylinder’s axis. Both distances are of course along the normal direction and w.r.t origin

b. LimitVelHigh: A node on the foot is only assumed to be in contact if its velocity w.r.t force plate is lesser than this value.

I am not sure of what you mean by being defined in two separate files. It could be that you’re using the same class to create two objects, each in a separate file.

Ananth
AnyBody Support