"Mesa Vibratoria" Will Help Prepare Future Peruvian Engineers

Located along the South American west coast and circumscribed by the Andean mountains on the east, Peru is a nation that experiences high seismic activity. For this reason, seismic resistant structures are paramount for Peruvians. Consequently, their civil engineers have accepted the challenge imposed by Mother Nature and therefore universities and research centers are preparing future engineers with the latest technologies for this purpose. The most recent acquisition of Universidad Federico Villarreal in Lima, Peru for the Civil Engineering Faculty has been the Quanser Shake Table II, so their students can run simulations of actual earthquakes.

I had the privilege of traveling to Peru for an on-site installation and training on the "mesa vibratoria" at the university, where I met Professor Omart Tello and his students. Professor Tello teaches Seismic Resistance Engineering to Civil Engineering students in their final year. It was clear that these students were very excited and motivated to learn how to operate the Shake Table II system. On the fist day of training, they quickly learned to set up and run the experiments using the two distinct methods: using the Graphical User Interface that Quanser provides for running Shake Table II experiments, and using QUARC/Simulink models. In the following day, the training was focused on recording results for further analysis and downloading and running other earthquake files from the PEER Strong Motion database.

Professor Tello (second from the left) and his team have many plans for using
the Quanser Shake Table II for teaching, as well as research.

Professor Tello plans to use the Shake Table II in various projects the students are working on, one of them being the development of a seismic isolator. Their projects include the addition of the Quanser Active Mass Damper (AMD) to the system. I'm confident that with this new resource for the Civil Engineering labs, students at Universidad Federico Villarreal will further expand their knowledge and research capabilities.

Quanser Shake Table Used for Validation of Sloshing Research

Free-surface dynamics of liquids in tanks subjected to acceleration - also known as sloshing - is an issue touching on many real life applications, including fluid transportation and shipping, as well as design of vibration absorber devices.

Researchers from the Universidad de Santiago de Chile, Chile, Universidad Nacional del Litoral, Argentina, Pontificia Universidad Catolica de Chile, Chile and Rice University, USA, studied the problem using the finite element analysis, based on solving the Navier-Stokes equations of incompressible fluids using a monolithic solver. To validate the numerical results, the research team used Quanser Shake Table II to control the motion of a rectangular tank with ultrasonic sensors.

Experimental setup with the Quanser Shake Table II loaded with the instrumented tank:
table controllers and ultrasonic sensor

The results of the team's research work was published in the December 2013 issue of the Computational Mechanics journal, in the article titled "Finite element computation and experimental validation of sloshing in rectangular tanks."

For more details on how researchers use Quanser platforms for control systems research validation, visit our website's Research Papers section or download the whitepaper The Quanser Platform for Control Systems Research Validation.

Elizabeth City State University adds Qs to its lab

The Aviation Science Program at the Elizabeth City State University’s Department of Technology is the only four-year collegiate aviation program in the State of North Carolina. Its uniqueness is now underlined by the latest additions of “Qs” to the department’s lab: that is, of Quanser Qball quadrotor and Qbot autonomous robot.

Setting up the Quanser UVS Lab at
the Elizabeth City State University

With these devices and a set of twelve NaturalPoint OptiTrack cameras, Dr. Rawat, Associate Professor and Department Chair can set up a complete unmanned multi-vehicle indoor lab and expand the Control Systems, Mechatronic System Design and Reconfigurable Computing courses, as well as undergraduate capstone projects. Plus the Quanser's Unmanned Vehicle Systems (UVS) lab  will be used for three new courses, begining in the fall 2014: Introduction to Autonomous Mobile Robotics, Advanced Mobile Robotics and Aerial Robotics.

The lab will be also used for research in areas such as sensor fusion, multi-agent collision avoidance and SLAM localization. Using twelve cameras, as opposed to a standard setup with six, allows for a larger workspace and makes it possible to expand the number of agents.

Thanks to the complete turn-key solution with controllers included, and on-site setup assistance from Quanser engineer, Dr. Rawat and his students could start their work right away. While all the sensors needed to cover topics of five courses using the unmanned vehicle lab are already on board, the open architecture design of the lab allows for addition of other sensors in the future.

 

Collaborative mission: first tests of Quanser Qball quadrotor and Qbot unmanned robot
at the Elizabeth City State University

Dr. Rawat also appreciates comprehensive documentation and courseware that come with the systems – that way he doesn’t have to develop all the course materials from scratch, but can reuse materials developed by Quanser. The supplied open-architecture controllers can also be modified for his educational and research needs, saving him time he would have to spend building controllers.

Dr. Rawat also hopes the demonstration of the cutting-edge unmanned technology will help his university attract high school students and excite them for a career in engineering.

WEBINAR: Enhancing Controls Education with the QUBE-Servo

The Quanser QUBE™-Servo is an affordable, fully-integrated rotary servo experiment designed for teaching students control concepts relevant to real world. Built with the same quality and precision that Quanser is renowned for, the QUBE-Servo provides instructors with a state of the art controls lab that will engage students in any engineering discipline.

In this webinar you will:

• Explore the QUBE-Servo and its easy-to-attach inertia disk and pendulum modules, as well as USB, direct I/O and the new NI myRIO connectivity options,
• Learn how to use the QUBE-Servo with MATLAB/Simulink or LabVIEW, and Quanser rapid control prototyping software QUARC or RCP Toolkit,
• Tour the flexible digital media-based courseware and textbook map that can help you seamlessly integrate the QUBE-Servo into your curriculum.

Seats are limited - register today!

Researchers from Brazil Use Quanser Platform for Control of an Active Suspension System

Quanser's Active Suspension
Platform

Researchers from the Control Research Laboratory at the Sao Paulo State University, Brazil, study different approaches to control active suspension systems. They use Quanser Active Suspension platform to simulate and analyze the effectiveness of their control strategies. The team summarized their work in a paper "Sliding mode control for Active Suspension System with Data Acquisition Delay," recently accepted for publishing in the Mathematical Problems in Engineering Journal.

The paper addresses the issue of delays that may occur in the PC-based control of an active suspension system. The signal delays can occur, for example, in a network-based control system or due to slow slow data acquisition. The research team proposes using state predictors with sliding-mode control to take delays into account. Both continuous-time and a discrete-time methods are designed and implemented on the Quanser Active Suspension system. Based on the results from simulations and hardware tests, the paper evaluates the effectiveness of these control strategies.

To learn how other researchers have used Quanser systems as experimental platforms for their research, visit www.quanser.com/research_papers. You can also download the whitepaper "The Quanser Platform for Control Systems Research Validation."

Queen's University Students Put Quanser’s Digital Control Curriculum to a Test

As an engineering student, I always loved to play with lab equipment. I have fond memories of building my very first controller to swing-up and balance an inverted pendulum in the last year of my undergrad. We were tasked to design a controller from scratch in Matlab/Simulink, test it with a system model and eventually implement it on the real hardware. I remember how I had discussions with other students about what assumptions we are using about the systems, how we could improve our model to get a better response and how to make our controller more “robust” for the real implementation. In the end, it all worked wonderfully well and I was hooked on Control Engineering.

Fast forward several years, lectures and hours in various labs and I am more and more amazed that it all worked. The one thing nobody seemed to have considered at the time was that we’re actually dealing with a discrete system and are using a digital controller to drive the hardware and stabilize the pendulum. Nobody was worried that their controllers designed for a continuous model would not work (or work well) in a digital implementation or that we didn’t have to design analog circuits to get real continuous controllers. Even nowadays, with superfast microprocessors available for only a few dollars, all they do in the end is running according to a (very fast) clock signal, but by no means in actual real-time.

Intuitively, it is clear that a controller’s performance running at a few megahertz will be hardly distinguishable from one that is purely continuous. However, it is also clear that implementing a continuous controller at very slow sampling rates will inevitably fail. In particular for a PID controller, we know that we are happy to deal with the discrete equivalents of the proportional and integral part of the controller, but what about the derivative part, in particular with respect to measurement/system noise and quantization errors in the feedback signal?

Students at Queen's University test the new digital control
curriculum during their Modeling and Computer Control of
Mechatronic Systems Course

To answer these questions (and more), Quanser has started to design a lab sequence to introduce students to common problems that are inherent to digital controller implementations. In particular, we’re investigating what effects different sampling rates have on the performance of a continuous PD position controller for the SRV02 Rotary Servo, how a continuous control design can be used as a starting point for a purely digital controller using the Matched-Zero-Pole mapping method for different sampling rates, and how to design a pure digital controller directly (and what the implications of different sampling rates on the design process). Furthermore, there is also a lab that investigates typical hardware implementation issues such as quantized measurement signals and buffer overruns. The overall goal is to enable the students to deal with real-world control constraints in their own hardware implementations, and therefore include discussions on how the lab material can be implemented in a programming environment (in high level pseudo-code).

My colleague Amir Haddadi and I had the chance to present the first part of the new lab sequence as part of Prof. Keyvan Hashtrudi-Zaad’s course on Modeling and Computer Control of Mechatronic Systems at Queen’s University in Kingston, Ontario last week. We were able to get the students started with the new curriculum in a hands-on lab on digital control, and the consensus seemed quite positive. A few students pointed out how the lab has helped them understand some of the theory discussed during the lectures and that they believe the labs will be beneficial for their upcoming design and research projects. We’ve also received valuable feedback from the students and TAs on the lab material and will implement it over the upcoming weeks.

At the moment, the first draft of the digital control labs is only available for the SRV02 Rotary Servo MATLAB/Simulink platform. Future releases will include an offering for LabVIEW, as well as for the Quanser QUBE-Servo platform (both MATLAB/Simulink and LabVIEW).

WEBINAR: Earthquake Simulation and Analysis

The structural dynamics and analysis topics are an important part of the engineering undergraduate and graduate curriculum in various engineering disciplines. Hands-on experiments, such as Quanser shake tables and smart structures seem to be particularly effective for teaching these topics, offering students a valuable extension of highly theoretical courses. Precise, robust, and flexible, they also meet the needs of researchers for reliable, low maintenance and cost-effective devices.

Join the webinar "Earthquake Simulation and Analysis with the Quanser Shake Table II" on Wednesday, March 19, 2 pm EDT and learn from Quanser engineers about the most popular of the shake tables product line, the Shake Table II, developed in cooperation with the University Consortium on Instructional Shake Tables (UCIST). The webinar will introduce you to:

• Solution overview - Shake Table II hardware, peripherals, and PC software options
• Running the experiments using the Shake Table II Software
• Running the experiments through the Quanser's QUARC Rapid Control Prototyping software
• Simulating earthquakes using the PEER Strong Motion Database data
• One-Floor Active Mass Damper (AMD-1)
• Fast Fourier Transform (FFT) of the structure acceleration data
• Other shake table offerings: Shake Table I-40 and the XY Shake Table III

Seats are limited - register today!