Laboratory model mass-spring-system

The system consists of an electrical drive and a weakly damped mass-spring arrangement. The position of the "bird" (mass) should follow a given reference signal. For this reason the controller is designed by loop shaping or as a continuous time state feedback controller.

Laboratory model double-mass oscillator

Two carts, mounted on rails, are connected by a spring. As input variable of the systems serves the voltage applied to the DC-motor of the right cart. The video clip above shows the so-called "chirp" experiment. A sinusoidal innput signal with rising frequency is applied to the system. As expected, the position of the second cart is also a sinusoidal signal. By looking at the amplitudes and the phase shift of the two sine waves the Bode diagram of the transfer function can be determined. Additionally the resonance frequency (about 3.4Hz) of the system can be observed. This leads to the conclusion that the system's transfer function possesses a conjugate complex pole pair. 

Laboratory model lifting magnet

The aim of this experiment is to levitate a ferromagnetic object beneath a electromagnet. The vertical position of the object is measured and should follow a specified reference signal. The difficulty of stabilization lies in the nonlinearity of the system.

Laboratory model Reaction Wheel Pendulum

The Reaction Wheel Pundulum is at first sight a quite simple electromechanic device. A DC motor with a flywhell is mounted at the end of the pendulum. By applying a voltage to the motor the flywheel gets into rotation. The torque which accelerates the wheel also produces a counter torque according to the "Actio=Reactio" principle. This counter torque leads to a oscillating motion of the pendulum. It is the aim to implement a control algorithm which allows the pendulum to swing up and remain in the unstable equilibrium point.

Laboratory model Quarter Vehicle

The quarter-vehicle serves for the testing of active-suspension control algorithms. The aim of the control circuit is to compensate road undulations and other disturbances, so that the driver of the vehicle notices as little pitch and rolling motion as possible. The laboratory model consists of three different masses, which are vertically displaceable. The top mass (blue) simulates the quarter vehicle body, which is connected by two springs with the middle mass, the "wheel" of the car (red). The active suspension mechanism is placed between vehicle mass and wheel mass and consists of a DC-motor. The middle mass is again linked by two springs to the lowest mass (grey) which represents the steet. It can be shifted by a DC motor to simulate different road profiles.

Laboratory model Two-Tank-System

The tank-system is equipped with a level control, with which the priniciple of state feedback control by linerarizing a nonlinear plant should be demonstrated. Starting with the experimental determination of the system's parameter for the nonlinear plant, a linear state feedback controller and extended state feedback controller (with reference signal input) are designed and tested. The main focus is on control quality with respect to parameter variation of the plant and additional disturbances.

Contact information

Institute of Automation and Control
Graz University of Technology
Inffeldgasse 21/B
8010 Graz

Tel.: +43 (0) 316 / 873 - 7021
Fax: +43 (0) 316 / 873 - 7028