Dear reader,

As you might have learned Adept Scientific was placed under administration recently.

Alfasoft AB has acquired several assets of Adept Scientific Limited with the intention to continue providing services on the best scientific software tools available. Please allow us a few days to reconfigure this web store for you. For inquires about Mathcad please send an email to

Alfasoft AB has provided high end scientific software in the Nordic countries since 1989 and we would be honored to give the same service to you.

Yours Sincerely,
Roberth Hoff-Olsen
Alfasoft AB

Linear Double Inverted Pendulum


Take the Classic Inverted Pendulum Challenge to the Next Level

The Linear Double Inverted Pendulum module is ideal to introduce intermediate and advanced control concepts, taking the classic single inverted pendulum challenge to the next level of complexity. You can use it to demonstrate real-world control challenges related, for example, to takeoff stabilization of a multi-stage rocket

The Linear Double Inverted Pendulum module is used attached to the Linear Servo Base Unit. With this setup students learn how to:

  • obtain a state-space representation of the open-loop system
  • design a state-feedback controller to balance a double pendulum, while tracking the linear servo cart position
  • simulate the system and use the designed state-feedback controller to ensure the system is stabilized
  • implement the controller and evaluate the system’s performance

In addition to teaching intermediate control concepts, the Linear Flexible Inverted Pendulum can be used for research in various areas, including robust and optimal control.

How It Works

The Double Inverted Pendulum module consists of two aluminum, precision-machined blue rods; one seven inches long and the other 12 inches long. The module easily attaches to the front pendulum shaft on the Linear Servo Base Unit cart and is free to rotate 360 degrees. The short link angle is sensed using the Linear Servo pendulum shaft encoder, while the medium length link is measured using the middle encoder mounted on the Linear Double Inverted Pendulum itself.

Based on the cart position and the pendulum angles, the balance control computes a voltage that is applied to the cart motor. The cart moves back and forth to balances the two pendulums and keep them in the upright, vertical position.

Quanser-developed Courseware Included

The Linear Double Inverted Pendulum comes with Quanser-developed courseware. The Laboratory Guide, together with quick start resources, a comprehensive User Manual, pre-designed controllers and a system model allow you to get your lab running faster, saving months of time typically required to develop lab materials.

Click here to view the Demonstration Video


  • Module easily attaches to front shaft of Linear Servo Base Unit
  • Two pendulum sizes supplied: medium and long
  • High resolution optical encoders to sense pendulum angle
  • Easy-connect cable and connectors
  • High quality aluminum and precision-crafted parts
  • Fully compatible with MATLAB®/Simulink® and LabVIEW™
  • Fully documented system models and parameters provided for MATLAB®, Simulink®, LabVIEW™ and Maple™
  • Open architecture design, allowing users to design their own controller

Curriculum Topics Provided

Topics included in the Quanser-developed courseware:

Modeling Topics

  • Derivation of dynamic model using Lagrange
  • State-space representation
  • Linearization

Control Topics

  • Linear-quadratic regulator (LQR)

The Linear Double Inverted Pendulum can be also used to teach other topics that are not included in the Quanser-developed courseware.

The Next Steps

What do our Customers say about us?

At 13-years old, my daughter’s research manuscript has been accepted for publication in a top tier peer-reviewed Environmental Science journal and OriginPro 8.6 will allow her to export the graphs in a wide variety of formats which can meet any publisher’s requirements. Kudos to OriginLab for designing innovative and intuitive software that can span the needs of both a burgeoning young scientist like my daughter to a PhD expert in their field. It is hard to imagine that other products offer this extraordinary level of user versatility.

Michael Grimmett, MD, FACP, FACS Ophthalmologist Palm Beach Gardens, Florida

Ref: Mathtype 6.6a. I love this product, thanks for decent support on this software

JT, Derbyshire, UK

I had just upgraded to Windows 7, and after having Mathcad for several years I found that I could not complete the final stages of installation. After reading help files I finished up confused and really helpless, until I contacted you. THANK YOU.

JD, Dorset, UK

Huge amount learnt, much more than I expected. Appreciate the ability of the programme much more than I did before.

PA, Liverpool, UK