I have some data for a model in MapleSim that I would like to use a time look up table with.  I've found that the two options for interpolation are linear and 1st derivative, but the data was intended to be interpretted as piecewise constant.  Is there any way to acheive this option in MapleSim?

Hi All. Hope all is well.

Assume that we have partitioned [0,a], into N equidistant subintervals and in each subinterval we have M sets of polynomials of arbitrary form[say b_ij(t)](a.e Taylor series, or Bernstein series,…)

for Example with N=4, M=3 and by Taylor series we have:

now we want to approximate a function, asy f(t), in this interval with following form:

If we have:

(Tau is a constant number)
then: How can  we find L and Z matrices using maple? Is it any way? (or other softwares?)

Regards

Mahmood   Dadkhah

Ph.D Candidate

Applied Mathematics Department

I was given that solitary initial state to see how it will deform as time goes on. am struggling to get my code so that I can get video frames. please help on how I can generate my code

u_o(x)= a₀x²(1-x)² for x (less than or equal to) x (less than or equal) 1

u₀(x)    = 0 for x > 1

the video clips will be representing the function u(*,t) :x to u(x,t)

for a sequence of choices of t such as t=0; t=0,5...t=3

 I have a complex set of mechanical linkages and components, and I am trying to create a feedback control system for trajectory-tracking with the end-effector. They system is driven by a set of prismatic joints (representing ideal series-elastic actuators). At this stage I am simply trying to establish the control parameters and the required forces to achieve desired positions/velocities in the workspace, and have not yet inserted any realistic actuator characteristics.

An open-loop solution can be found using translational position control on the prismatic joints, this is no problem. However to close the loop properly, I need to convert the system to use a differential input, such as a velocity driver. At this point everything becomes very finicky and highly dependent on initial conditions. Generally Maplesim gives up, claiming that no solution can be found. Due to the complexity of the system, there is no way for me to guess a priori the appropriate initial conditions of all the joints and linkages. I was wondering if anybody had any tips for either pre-determining the initial parameters, or alternatively for relaxing the solver in some way to allow for a wider exploration of possible solutions. Or any other ideas!

So far: I have tried setting up an open loop position-driven system with the same trajectories and using Maple to read all the initial conditions, then transferring them as guesses to my closed-loop system. But this has not worked. As a temporary workaround I am using position drivers on the SEAs, which are in turn driven by a velocity controller (with an integrator term). However this is suboptimal. Any help would be much appreciated!

Hi, this question is for Samir Kahn or other maplesoft staff.

Is there a way to use modelica biochem or any other chemical path library into maplesim? Do you plan to integrate this library in future versions of maplesim? Wolfram systemModeler has this library already integrated as does symbiology in matlab. Mr Kahn, I hope that your background in chemical engineering help you push for this new development in maplesim and help this product be even better than the competion. thank you and let me know as soon as possible.

juan

Hi

I want to create a linearied model for a single or multi degree of freedom vibration system by MapleSim. i faced a lot of problem such as causalize ports, i search the user manual but i didn't find it useful. i attach a very simply one degree of freedom vibration system. i wondering if every one create a linearized model for it. my final goal is governing the equation and determine the natural frequency with nyquist plots. i have mapleSim 6.2 and Maple 17. Thanks

prob1.msim

Hi MaplePrimers!

I have a simulation in MapleSIM, exported as a compiled procedure in maple using -LinkModel(), and -GetCompiledProc.

I'm trying to do parameter estimation on my MapleSIM model.  Within a optimization scheme, I call the MapleSIM model, and it will output a curve.  Using a least squares method, I compare this measurements to synthetic experimental data (I know the actual values), and generate an objective function.  The optimization algorithm will try different parameter values, and try to minimze the objective function.  When the curves are exactly the same, the objective function will be zero.

The problem I am having is certain parameter sets will cause the model to require very small steps.  I wish to put a timeout on these experiments, because speed is important.  However, I would also like to see the results up to the point of requiring very small steps.  For timeout, I was using code along the lines of:

out:= timelimit(30,cProc(params = PData)); #simulate with 30s limit

where PData are the parameter guessses, and cProc is the compiled MapleSim model.

I would like 'out' to be assigned whatever the results were after 30 seconds, even if the model had not finished integrating.

Thanks in advance for any help!

Hi,

Does Maplesim allow hardware integration such as a joystick so that I can feed in joystick commands (via USB or serial) from the computer and then control my Maplesim model in the virtual space? Suggestions?

Thank you.

Hi,

I'm currently working on a manipulator model in Maplesim and will import CAD attachments to each of the links. The Solidworks model, once imported to Maplesim, is not located in the same position as the Maplesim part but is offset by X,Y,Z. The scaling is also off. Is there some way to align the CAD to the component instead of trial and error?

Thank you.

Hello everyone!  

I am very new to the maplesoft community but am very impressed with everything I have learned in the last few days.  I'm having an issue using force probes on a double wishbone suspension that I'm hoping someone can help me with.  I am trying to measure the forces in each link to gather quantitative solutions for the forces at the chassis connection points.  However, I keep getting one of the links measuring no value at all.  The...

Hello,

I need to model universal joint and spherical joint with spring elements.

Contrary to the revolute joint where there is an option to put spring element, i don't find this option in the universal joint and the spherical joint. So is there a simple solution to model spring in this kind of joint.

I hope that i shouln't have to build the joint with several revolute joint in serial.

Thank you for your help.

Hello,

I have a little question concerning the definition of the rotation matrix in the rigid body frame.

The rotation matrix is defined like that in the help menu : "The rotation matrix that transforms a vector expressed in the outboard frame to the inboard frame".

Consequently, we have :

Hello,

In multibodies system, there exists many kind of coordinates namely joint (or relative) coordinates and absolute coordinates. Moreover, for the joint (or relative) coordinates, it is possible to choose strict, simplified, or complete coordinates.

For the moment, i only find in the tutorials system modeled with complete joint (or relative) coordinates. I will give the example of a 4 bars mechanism. The kinematic scheme with this complete joint coordinates is the following :

MapleSim already developed a Template for Linearization.

The code behind "Linearize" button in the Linearization template is as follows:

"MapleSim:-Templates:-Linearization:-Linearize();"

The results, namely A,B,C,D matrices in the state-space presentation, are shown in the text area "mcEqs".

How can I save these matrices to some variables for further analysis?

In addition, without the linearization template,