Solve

[XDN]

Hi

I write a new calculus sheet, with it, i want to calculate a kinematic for parallel glide structure(  is it a Clavel's Delta robot variation)

In my sheet, i don't understand why prime don't solve the last equation

see attached file

Anyone can help me ?

[Werner_E]

The reason is that OP.i is a matrix and so is the RHS of your equation!

If you clear OP.i (and L) for symbolic calcs, you get a symbolic result

[XDN]

Great ! ( i don't know clear function.)

It is possible to use it in program for calculate  all value for

B1_z ; B2_z ; B3_z

I need to calculate it for each leg

I don't know to make it in one program. I want this program give me B1_z ; B2_z ; B3_z for control robot

[XDN]

Another question:

it is possible to keep only positive root, and , it is possible to assign this solve result to a new variable ?

[Werner_E]

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@XDN wrote:

Another question:

it is possible to keep only positive root, and , it is possible to assign this solve result to a new variable ?

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Yes, it may be possible to return the positive root alone but it will require a couple of "assume" modifiers because the symbolic has to be told if the variables you are not solving for are real, positive, etc.

And yes, you may assign the solve result to a variable, better yet to a function!

[XDN]

whow !! i don't know how to do that🙄

[Werner_E]

The result depends on eight input variables

A.ix,A.iy,A.iz,O.x,O.y(is missing, is this a typo?), O.z, OP.i and L

You may assign the symbolic solve to a function with those eight arguments.

[XDN]

Ok

But i don't know to make it.

I try to explain my problem, certainly i'm not clear, sorry for this.

I have a vector problem

 In this picture

I have 3 linear actuator :

1. Axis A1 to B1
2. Axis A2 to B2
3. Axis A3 to B3

The Ai points are fixed ( i know each Ai) , the Bi point are moved. More presicely the Bi point moving is only on z axis (xy value for Bi point is know, and they are xy value from Ai)

The C point is the point of interest.

And is this point to move.

When i want to drive this robot, i give C coordinates (X,Y,Z) ( I make the inverse kinematic model)

And, C points coordinates values are know.

I know by building the L parameter , L is the standard vector ||BiPi||

And after that i calculate the kinematic close loop with vector, as in my sheet

Is that i want to use symbolic function in Prime

And finally , i want calcul the displacement parameter along each linear axis

This parameter is only  Bi coordinates along z axis.

And after i drive my motor with this parameter.

Sorry, i'm bad in mathcad use ...

I don't know how to do it, for realise your idea

[Werner_E]

Sorry, I don't know how to set up your kinematic problem.

I had not looked at the rest of your sheet, just at the last solve region to see why it didn't solve.

[XDN]

Do not be sorry,

I try to explain my kinematic problem for a global view

The kinematic, is not problem.

My problem is write equation in Prime with progam function using.

[ValeryOchkov]

May be the study 8 from the book

2^5 Problems for STEM Education 

will be useful for you.

See please animations from this study

New art form with Mathcad 

[XDN]

Ok

I want to learn Mathcad ( i buy your book now )

Thanks

[ValeryOchkov]

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@XDN wrote:

Ok

I want to learn Mathcad ( i buy your book now )

Thanks

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Thank you!

[ValeryOchkov]

One part of the book is free