## May Live Webinars

Maplesoft regularly hosts live webinars on a variety of topics. Below you will find details on some upcoming webinars we think may be of interest to the MaplePrimes community.  For the complete list of upcoming webinars, visit our website.

Hollywood Math (with more new examples!)

Over its storied and intriguing history, Hollywood has entertained us with many mathematical moments in film. John Nash in “A Beautiful Mind,” the brilliant janitor in “Good Will Hunting,” the number theory genius in “Pi,” and even Abbott and Costello are just a few of the Hollywood “mathematicians” that come to mind.

Although the widespread presentation of mathematics on the silver screen is not always entirely accurate, it does serve as a great introduction to the study of mathematics in general. During this webinar Maplesoft will present a number of examples of mathematics in film. See relevant, exciting examples that you can use to engage your students.At the end of the webinar you’ll be given an opportunity to download an application containing all of the Hollywood examples that we demonstrate.

Applications of Symbolic Computation in Control Design

You may already use Maple and/or MapleSim within your organization to solve various problems, but did you know that they have capabilities for control design as well? In one of our upcoming featured webinars for this month, we will explore the Control Design toolbox including the ability to extract symbolic equations of plant models, perform symbolic linearization, design symbolic controllers, and generate very fast code for HIL testing.

The following examples will be demonstrated:

• PID Control

• LQR, Kalman filter design

• Gain scheduling

• Feedback linearization

## How can I precalculate appropriate initial conditi...

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

## Beg for a model(speed control of DC motor)...

Recently I started to learn to use maplesim. I wanted to set up a feedback system which is used to control the speed of DC motor. I don't know how to build it. Please give me some advice. I really appreciate your help.

## How to create linearized model for a single degree...

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

## MapleSim 6.4 is now available

MapleSim 6.4 includes more powerful tools for creating custom components, performance enhancements, and enhancements to the model generators for Simulink® and FMI.

We have also made important updates to the MapleSim Control Design Toolbox. This toolbox now offers a more complete set of algorithms for PID control, new commands for computing closed-loop transfer functions, and numerous improvements to existing commands. These enhancements allow engineers to design a greater variety of controllers and controller-observer systems while taking advantage of the greater flexibility and analysis options available through the use of symbolic parameters.

eithne

## How to put out the simulation data of the MapleSim...

After simulate the model of MapleSim, I can only know the curve of where I need to know about. I need the specific parameter(each point value), like a piece of sheet. How I can put it of in an Excel of Word?

## Modelica support...

Hi

Is MapleSim 6.1 fully Modelica 3.1 compliant? If not, which features does it miss for the moment?

Lookup tables? (modelica ones, not maplesim's)

Thank you very much

## Virtual User Summit

Maplesoft is holding its first ever Virtual User Summit on Feb. 27.  You’ll be able to watch presentations by both Maplesoft and Maplesoft customers, ask questions, have discussions in the lounge with other attendees, and even enter a draw, all from the comfort of your own home or office.

Here’s the agenda.  We’ll release more detailed information on speakers and session times in the next couple of weeks.

We're looking forward to seeing you there. (Well, "seeing you" :-))

eithne

## over detemined system...

i have got alot of mixed and high degree derivatives. For example:

u[x]*u[x,t]*eta[x,t]+u[]^2*u[x]*eta[x]+kis(x,y)u[x,t]^2*u[]+eta(x, y)*u[]*u[x]^2+ksi[x,t]*u[x]^2*u[x,t]+......

like this alot of terms

my question is how can i solve divided by the derivative of the u(x,t) partial differential equations system and so  how can i find eta(x,t,u) and ksi(x,t,u)

## Is there a way to see integration results for simu...

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!

## to get values of block variable...

Hello, could you give me ideas with such challenge? I have created my model in MapleSim and want to check correctness of the scheme. I need to get values of block variable. by default maplesim displays results as a graph and i do not see what is real value. How I can get these values?

## installation maplesim on windows 8...

Hello,

I tried to install maplesim on windows 8 but it didn't work.

However, i have installed microsoft visual c++ express before and i have made the precedure as described in maple that is to say

or