A self-tuning controller for frequency control of power systems by HVDC. One of the advantages of High Voltage Direct Current, HVDC, is the possibility to control the power flow between different parts of an A.C. network. This property is being used when disturbances in the frequency, caused by load variations, is eliminated. Simulation studies on a physically scaled model of the "Gotland-tr

Fermentation in a 5 l continuous flow reactor with immobilized yeastcells is controlled. Substrate concentration (sucrose) is continuosly measured with an enzyme thermistor. The control variable is flowrate through the reactor. The main controlproblem is a timelag in the measurementsignal. A bilinear processmodel is formulated and used for design of different controllers. Comparison is done betwee

A real-time kernel in Pascal for a Motorola MC 68000 mikroprocessor has been implemented to be used on ASEA's DS101 microcomputer system. An arbitrary number of processes can be executing concurrently. The following primitives for process synchronization are available. 1. Priority, 2. Semaphores, 3. Message passing, 4. Monitors, 5. Waittime, 6. Vectoried interrupt. The processes are realized a

The report presents a scheme for self-tuning regulators based on gradient methods. The feasibility of the scheme is studied in some special cases. The scheme is used together with different estimation techniques such as extended least squares (ELS) method and indirect estimation using a one to one correspondance with the regulator parameters. The method is illustrated using simulations of two diff

The programs are made to decide testing points in an integrated circuit. The measurements on the IC are performed in a SEM using digital electronbeamdeflection and digital secondary-electrondetection. A PDP11/23 computer and a QRGB-256 video-interface are used. Programs are written in MACRO-assembler and FORTRAN. Pictures may be taken up and stored on a mass storage (floppy-disk) for later retriev

The subject of this master thesis was originally proposed by the electronic company Telsand Electronics in Arlöv. The purpose was to examine the possibilities to implement digital controllers on a one board computer based on Texas Instrument microprocessor TMS 9995. We have implemented a certain type of PID-regulator and designed both hardware and software solutions. Because of lack of time, we ha

Following report describes a computerized measuring system based on the Swedish micro-computer ABC 80. The system was able to handle up to 30 measuring channels. Received measuring data was stored on a diskette. The control of the system was carried out by a program in the computer. For analysis of the result, a few programs were developed. The system was applied on a margarine-making process and

In this report, the dynamics of an aertor of an activated sludge process is studied. Two control strategies for the dissolved oxygen concentration are tested. One contains either a PI-controller or an on-off controller, the other a self-tuning controller. There are two key-parameters in the system, KLa, the total oxygen transfer rate, and OUR, the oxygen uptake rate of the microorganisms in the a