## 190 Reputation

19 years, 148 days
Dr. Gilbert Lai is an independent consultant. He is also a mentor for FIRST Robotics team SWAT 771 (http://swat771.com). As a former employee of Maplesoft, he was team lead in the MapleSim simulation engine development team and was technical adviser on various MapleSim add-on toolboxes.

Trained as a Computer Engineer, Dr. Lai’s research interests include robotics control (force feedback teleoperation), aerospace and mechatronics applications (helicopter modelling and control). In his spare time, he enjoys computer games, Sci-Fi movies and quality time with his family.

## Pitching Machine......

No credit will be claimed for my team on the shooter design, of course, as we did not "reinvent the wheel" :)

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Gilbert Lai, PhD

## The rotation defined with the RBF is to ...

I used the extra rigid body frame to adjust the orientation of the base frame of reference, which is used to measure the joint angle from.  Think about it as an offset to your sensor measurement data.  It is relevant only with respective to which axis you want as your reference axis for measuring the angle (i.e. either x or y) and whether your rod orientation is along x or y direction.

If you find that you sensor measurement is what you expect it to be, there is no need to add the extra rigid body frame.

Hope this helps.

Cheers,

Gilbert

## The rotation defined with the RBF is to ...

I used the extra rigid body frame to adjust the orientation of the base frame of reference, which is used to measure the joint angle from.  Think about it as an offset to your sensor measurement data.  It is relevant only with respective to which axis you want as your reference axis for measuring the angle (i.e. either x or y) and whether your rod orientation is along x or y direction.

If you find that you sensor measurement is what you expect it to be, there is no need to add the extra rigid body frame.

Hope this helps.

Cheers,

Gilbert

## Can you provide us with the model for in...

Also, which version of MapleSim does this happen to?

Thanks!

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Gilbert Lai, PhD

Senior Applications Engineer, R&D Applications Engineering

Maplesoft

## Not sure if you have resolved your issue...

If not, can you send us the model so we can help investigate why it is running slowly for you.

Alternatively, if you are unable to send us the model, can you at least send us the log message (from the console window in the bottom) when running the simulation with Verbose mode. That should at least give us some indication of the breakdown of the timing within the simulation engine (from which, hopefully, we can find out why the model runs slowly).

Thanks!

==============================

Gilbert Lai, PhD

Senior Applications Engineer, R&D Applications Engineering

Maplesoft

## Along the same line of thinking......

I suppose we could use the Dot Product (?componentLibrary/signalBlocks/math/operators/DotProduct) to get the term directly instead of computing r with the Vector Norm block and then squaring it...

## Along the same line of thinking......

I suppose we could use the Dot Product (?componentLibrary/signalBlocks/math/operators/DotProduct) to get the term directly instead of computing r with the Vector Norm block and then squaring it...

## The MapleSim component help page is also...

Here is the link to the MapleSim help page for the flexible beam component:

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Gilbert Lai, PhD

Senior Applications Engineer, R&D Applications Engineering

Maplesoft

## The MapleSim component help page is also...

Here is the link to the MapleSim help page for the flexible beam component:

==============================

Gilbert Lai, PhD

Senior Applications Engineer, R&D Applications Engineering

Maplesoft

## Time out problem......

This is another me-too for the time out problem. I am using FireFox 1.5.0.1 on Windows 2000. (Where, if there is such option available, and what should I do to setup my browser so I don't see any timeout?) Thanks! Gilbert ================================ Applications Engineer, Maplesoft

## Maple Calculator?...

I am not sure if this is relevant, but Maple 10 comes with a Maple Calculator (if you are using Windows, an icon should be installed on your desktop). In the calculator, you can specify the use of degrees instead of radians under the Setting tab. Hope this helps! Gilbert ================================ Applications Engineer, Maplesoft

## Maple Calculator?...

I am not sure if this is relevant, but Maple 10 comes with a Maple Calculator (if you are using Windows, an icon should be installed on your desktop). In the calculator, you can specify the use of degrees instead of radians under the Setting tab. Hope this helps! Gilbert ================================ Applications Engineer, Maplesoft

## Runs fine with Maple 9.5...

I agree with Joe.
Your commands seem to be running fine under Maple 9.5.
What is the problem?

> restart;

> with(inttrans);

> y:=(2.5)/((8*s^2+6*s+1)*s);

> y1:=invlaplace(y,s,t);
plot(y1,t=0..25);

> y:=(2.5*exp(-1.5*s))/((8*s^2+6*s+1)*s);
y1:=invlaplace(y,s,t);
plot(y1,t=0..25);

> ode := 8*(diff(x(t), t, t))+6*(diff(x(t), t))+x(t) = 2.5*Heaviside(t-1.5);
ics := x(0) = 0, (D(x))(0) = 0;
sol := dsolve({ics, ode}, x(t), numeric, stiff = true, range = 0 .. 25);
plots[odeplot](sol);

>

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Gilbert
================================
Applications Engineer, Maplesoft

## Runs fine with Maple 9.5...

I agree with Joe.
Your commands seem to be running fine under Maple 9.5.
What is the problem?

> restart;

> with(inttrans);

> y:=(2.5)/((8*s^2+6*s+1)*s);

> y1:=invlaplace(y,s,t);
plot(y1,t=0..25);

> y:=(2.5*exp(-1.5*s))/((8*s^2+6*s+1)*s);
y1:=invlaplace(y,s,t);
plot(y1,t=0..25);

> ode := 8*(diff(x(t), t, t))+6*(diff(x(t), t))+x(t) = 2.5*Heaviside(t-1.5);
ics := x(0) = 0, (D(x))(0) = 0;
sol := dsolve({ics, ode}, x(t), numeric, stiff = true, range = 0 .. 25);
plots[odeplot](sol);

>

This post generated using the online HTML conversion tool