Help with completion of Accelerometer and Heel force VI please

[mbrolly2]

Hi all,

First off I'm very stressed as regards to trying to complete this full package, let me explain a little further. Essentially I have 3 VI's an EMG VI and Accelerometer (Trunk Tilt) VI and an FSR (Heel Force) VI. The idea behind the VI is to simulate signals received from the aforementioned instruments during a Sit to Stand movement (EMG on the quadriceps, Accelerometer on the chest, FSR on the heels). Firstly the EMG is working fine and I am happy with it. 

-A full sit to stand movement should take less than 2 seconds. I will add a rough sketch of how the signals should look on one graph. It is required that I place the 3 signals on one graph.

-The accelerometer VI is not working fully for me and the timing part of the VI is off. I will attach the VI I have completed so far and a sketch of what I would like to have and what I need to have adjustable. 

-The FSR VI I have so far is very crude and far off from what I need it to look like, I just copied what I have done from the Accelerometer VI. I too will add a picture of what I result I should have and what needs to be adjustable. 

-Finally I need a sit to stand detector that receives the signals from the graph and alerts when the criteria are met. I will add some pictures which may be of some help.

Thank you with sincere gratitude if anyone can help me. I'm still learning.

Kind Regards,

Mark

[mbrolly2]

Pictures as promised.

Kind Regards

Mark

[mbrolly2]

And the final 2. Any help would be greatly appreciated.

Kind Regards

[mbrolly2]

Bump.

Anybody got any ideas or can help?

Regards,

Mark.

[GerdW]

Hi mbrolly,

instead of "inserting at end of array" you could simply concatenate your arrays:

From your (unfocused) images I would guess you need to add more parts to your signal than just 3 rather constant ranges…

[mbrolly2]

Hi GerdW,

I made the the adjustments as you have suggested, thank you. How would you suggest I reduce the time on the Accelerometer VI and FSR VI down to 10 seconds and have the "dips" in the sine wave to appear at roughly 1.7 seconds?

Kind Regards,

Mark.

[Justin.]

Hey mbrolly2,

I also took a quick look at your accelerometer VI. Could you just make dimension sizes controls? To adjust how far along the graph the dip appears?

At a maximum angle of 50 and having 50 samples allowed me to recreate the graph you drew, with the dimension sizes constant. But equally if I alter the dimension sizes of the arrays, i.e. how many 90 values are produced before inserting the sine half-wave dip, this moves the graph to wherever I want either side.

Is that a reasonable thing to do in this code or have I missed the point of the VI?

[mbrolly2]

Hi Justin,

Thanks for your reply, I'm not sure if I follow, I changed the values of maximum angle and samples to 50 and I still have a huge time. How would I get this below 10 and the dip at 1.7?

Apologies if I'm not being clear enough, thanks for your patience.

Regards,

Mark

[Justin.]

Hey mbrolly2,

Admittedly I'm not too familiar with what you are attempting, so sorry if I've missed the point here, but the time parameter seems a little meaningless to me at the moment. 

Your x-axis is defined by you when you set your array size. The title of time is attributed to the graph by default.

You are plotting an array of 90 values, with a sine halfwave dip inserted. The x-axis is just giving you every point in the array.
128 + 512 = 740 which is where your graph stops as this is the amount of points you created in the array.

If you need the x-axis to read between 0 and 10 you can program that but it doesn't really relate to any actual timing.

[mbrolly2]

Hi Justin,

The idea behind it is I'm trying to simulate what would be coming out of a biomedical instrument with an accelerometer attached to your chest. The sit to stand test should only be between 0-2 seconds to complete a sit to stand movement (sitting up from the chair) so that is why the timing has to represent that.

Would you recommend I change the inputs to the arrays and that will fix the x-axis/time for me?

Kind Regards,

Mark