presented algorithms. An example illustrates the algorithms' applicability.
035 Pneumatic Posltioner with Fuzzy Control G. Belforte, T. Raparelil, M. Velardocchla, pp 229-234 A pneumatic positioner with closed-loop fuzzy logic control is described. The system consists of a pneumatic cylinder, two proportional valves, a position and speed sensor, a fuzzy controller and an A/D-D/A conversion board. No braking devices are provided. The control considers position error and actuator speed as antecedents, and valve control voltages as consequents. Membership functions, the set of rules and the weights of each were obtained. Experimental tests were carried out with different reference signal shapes and different applied loads. Results show good positioning accuracy and repeatability, absence of overshoot and system stability under varying operating conditions.
036 Development of a Fuzzy Controller for a DC Drive S. Bolognani, M. Zigliotto, pp 235-240 The paper deals with the design and the development of a Fuzzy Logic Controller (FLC) for the speed and current control of a DC motor drive. The fundamentals of the FLCs are preliminarily illustrated. Details on the design of the fuzzy algorithm and scaling factors are then given. Furthermore the implementation of the controller exhibits short cycle time and small memory requirements. An interpolation algorithm is used in reading the look-up tables to reduce the quantization troubles. Experimental results show the good dynamic performance of the drive.
037 Active Position Control of Dynamic Platforms K. Bouazza-Marouf, J.R. Hewit, pp 241-246 The loading and unloading of offshore supply vessels pose severe problems in adverse weather conditions when the supply vessel may be heaving, pitching and rolling violently. This is currently overcome by relying on the crane operator's skill and weather windows, which may be dangerous and costly. A dynamic platform system (DPS) is proposed here to solve the problem of offshore load transfers. A method of control based on the principle of invariance is used here on an experimental rig to investigate the control problem of disturbance isolation of the DPS. Good results have been obtained.
038 Communication Techniques for Electric Drives G.S. Buja, pp 247-252 The paper gives a tutorial on the communication techniques for electric drives. After reviewing the different interfaces of a drive and the associated data flow, the basic techniques are identified and their distinctive features are illustrated. The main standards are also addressed, together with their most significant characteristics.
039 Microprocessors Systems for Motion Control T. Ohmae, M. Watanabe, pp 253-258 This paper presents a review of the recent advances in microcomputer-based motion control systems. First, the trends of microcomputers and systems are described. As a result, it is shown that multiple microcomputer systems are suitable for motion control. Rolling mill main drives
and robots are used as the application examples and their hardware configurations are described. Furthermore, some of the future technical trends of the above systems are also described.
040 Vision Based Motion Control Application for Factory Automation M. Nomura, N. Watanabe, pp 259-263 This report presents a vehicle equipped with a camera inside. The camera obtains an image of a road surface, and the movement of the vehicle is calculated with a change of image. The vehicle travels along courses stored in memory set up beforehand. The spatial filter method was applied to analyze the image data for measurement position and direction of the vehicle. As the position error is integrated in this system, image processing was used for detection of landmarks that are placed at suitable intervals along a travelling route. Experimental results are described in this report.
041 Pulse-Width and VSS-Modulated Controllers in Motion Systems P.P.J. van den Bosch, A.E. van den Groef, H.R. Visser, pp 265-270 Discrete pulse modulation is necessary to convert a continuous signal into a binary signal to control switches. This paper compares state feedback modulated with PWM with a controller based on variable structure systems (VSS) equipped with hysteresis. Simulations with an AC-DC converter are used to calculate the frequency spectra. It is shown that VSS with hysteresis considerably reduces the peak harmonic values in the frequency spectra. Compared with other peak-value reducing measures, VSS yields attractive results during transients and in AC-operation.
042 Fuzzy Logic Controller Design Based on Variable Structure Control T.T. Lee, K.Y. Tu, pp 271-276 This paper proposes a Fuzzy Logic Controller (FLC) that is based on the VSS to form the linguistic rules. Firstly, it is proved that there exists a sliding line in the Fi.,C. Secondly, a Lyapunov function is selected to show that the Fuzzy Controller System (FCS) is globally asymptotically stable. The proposed control method is applied to stabilize a cart-pole system. In addition, the effect of adjusting the scaling factor, varying the rules of VSS, and modifying the membership function on the FCS are also addressed.
043 Digital Sliding Mode Torque Control for Induction Servo Drives J. Moerschell, pp 277-282 This paper describes a sliding mode torque controller for voltage source inverter fed squirrel cage induction motors. Flux imposition is achieved through reactive torque control. The inverter switching commands are derived from the active and reactive torque comparator outputs and from the equivalent machine voltage. The theory of sliding mode control is used to describe the behaviour of the control structure. The torques are determined using a state space observer. All mathematical analysis is done by using complex variables representing the space vectors. A fully digital realization of the control method, based on dedicated hardware, is studied.