The research includes combination of both theoretical studies and their practical applications to robotics and nonlinear systems. Some activities of the laboratory are summarized below.

Computational Intelligence

The area of computational intelligence has emerged as the combination of different methodologies in need to find computationally efficient solutions to complex problems. Our laboratory is actively involved in different aspects of computationally intelligent systems research and has strong expertise in this area which has led to contribution of several publications to the relevant literature.

Especially, recently developed techniques for variable structure systems (VSS) based training of intelligent architectures are very promising. The incorporation of VSS theory into learning algorithms brings together important benefits such as robustness and increase in stability, which are highly desired properties for control applications.

MPS 500

The MPS 500 system is a successively expandable system consisting of individual stations. However, the central unit is always the transport system. The MPS 500 system is designed in such a way, that the amount and kind of attached MPS-stations attached is not important. A complete processing cycle of the work-piece is always warranted. Therefore, the transport system is required under any circumstances. In complete set-up, the work-piece is separated from the distribution station to be transferred to the testing station. The testing station checks the condition of the work-pieces, ejects junk in case of occurrence and transfers the faultless pieces to the transport system. Consequently, the product input into the system takes place from the distribution station. In case the distribution station does not exist in the system, the work-piece can be placed onto a work-piece carrier, anywhere in the system. It is to be noted that no work-piece carriers should be extracted/removed from the system.

The processing station is loaded a PIC-alfa station. The work-piece receives processing, followed by testing. The PIC-alfa station returns the work-piece to the transport system. The work-piece is tested for shape tolerance in the vision station. The robot station assembles a model cylinder from a basic body. 

The AS/RS station is able to store work-pieces and, on demand, returns them to the system. In the sorting/commissioning station the work-pieces can be re-retrieved from the system. The work-pieces are transported from the transport system to the sorting station by a PIC-alfa station, where the work-pieces are arranged according to colour, ready for product output.

From the commissioning station the work-pieces are not released by colour, but by the number of pieces. Each time 18 pieces are commissioned. The three upper slides are on stand-by for the work-pieces, the fourth slide is for parts storage in the adjustment process.

Testing of the work-pieces for their condition, according to type, is required in the station. The work-piece carriers are distinguishable by their drillings on the underside, but they do not carry any work-piece information. Therefore only this assures correct processing.   The transport system is responsible for the transport of the work-pieces within the system, which consists of various stations. A transport system comes into action to ensure faultless carriage of work-pieces over long distances between stations.   Control of the transport system is realized by a Siemens S7, for which a control cabinet is available, mounted onto the basic frame of the station. The station’s internal data transmission ensues by an ASi-bus. Transmission to the other stations is realized by an exactly defined I/O-interface.

ABS (Anti-lock Braking System)

Key Features Laboratory model of one-wheel ABS system Car velocity range from 0 to 50 km/h Slip control under different road conditions Rapid prototyping of real-time control algorithms (no C code programming) Full integration with MATLAB © / Simulink ©. Operation in real-time in MS Windows © 95/98/NT /2000 Simulink models and teaching manuals included Library of pre-programmed control algorithms

Description

Antilock Braking Systems (ABS) are designed to optimize braking effectiveness while maintaining car controllability. The performance of ABS can be demonstrated in our lab-set (see the schematic diagram and the photo) by simulation for various road condition and transition between such conditions (e.g., when emergency braking occurs and the road switches from dry to wet or vice versa).

The shortest braking distance corresponds to the slip equal to 100%. However, the car controllability is lost. The main goal of braking is to minimize the car braking distance following the rule: the less the slip the better car control.

Research On Robotic Manipulators

2DOF SCARA type open architecture manipulator available in the laboratory is used for experimental studies. The work involves the implementation of intelligent control approaches developed by our research team and allows making improvements on the new algorithms for practical applications. Recently, with the addition of a 5DOF CRS/Quanser open architecture manipulator to the experimental setups available in the laboratory, it has become possible to extend the domains of research even further. A setup in which an inverted pendulum is stabilized by movements of the manipulator is successfully implemented. Moreover, it is planned to use visual feedback information in corporation with the manipulator for machine vision based intelligent robotic applications in the near future.

Autonomous Mobile Robot Project

The goal of this project is to design an autonomous mobile robot, which behaves in an intelligent manner; that is it can recognize the changes in the environment and adapt to these changes, so that a given objective can be accomplished. Currently, the project is in the development phase. The final system will be composed of a mobile platform and a central computer. The sensory information will be obtained by means of virtual sensors that use fusion of the information coming from the shaft encoders and a CCD camera in order to obtain more reliable measurements. The visual feedback utilized in the system will also ease the map construction and path planning tasks in the context of dynamic obstacle avoidance. The information exchange between the mobile platform and the central computer will be provided by means of a RF communication link.

Other research activities

The control research conducted in the laboratory is not limited with the aforementioned activities. Three-tank experimental setup, which is a highly nonlinear system with strong couplings between states, constitutes a good test bed for nonlinear system design. Recently, a fuzzy controller is designed for control of liquid level on the tanks. Apart from that, a Java based interface is also developed for the system which increases interactivity and can be used for web-based control with minor updates. Moreover, there are additional control setups in the laboratory such as ball and the beam, inverted pendulum with car and nonlinear system simulator which can be utilized for further research.