Design And Implementation Of An Environmental Chamber Digital Control System

The DC-DC converters at the Advanced Photo Source at Argonne National Laboratory are over 15 years old. An upgrade to digital control system is being evaluated to resolve the aging and obsolescence issues. These converters supply power to electromagnets that are used to guide high energy beams. Thus a highly accurate control system is required for the DC-DC converters. This paper describes the design and evaluation of a digital control system to regulate the output current. The digital control system is proposed to replace the current analog control system thereby resolving the aging and obsolescence issues. A digital controller is first designed based on the small signal model of the converter. Experimental data of the output current is analyzed. The complete control system is then simulated and results are evaluated.

Recently, the Plant Input Mapping (PIM) method was proposed as a digital-redesign (or an emulation) approach in digital control system design. This method guarantees stability of a redesigned digital control system for a wide range of sampling periods. In this paper the PIM method is applied to the design of a digital model-matching flight control system. In the model-matching control system design a plant must have no unstable zeros. However, unstable zeros appear for small sampling periods in a step invariance model of a continuous-time (CT) plant with the relative degree greater than two, even if the CT plant has no unstable zeros. Hence, in such a case, the direct-digital approach cannot be applied to the design of a digital model-matching control system. By contrast, the digital-redesign approach such as the Tustin's method or the PIM method is free from the problem. Simulation results for an unstable VTOL aircraft show that the proposed method gives better performance than the conventional design methods.

This paper considers the application of error analysis algorithms for the linear quadratic gaussian problem to the design of digital control systems for a simple model of a helicopter in hover. Particularly, we investigate the influence on the performance of modelling errors in the stability derivatives and correlation time of the wind gust model. The algorithms presented enable the determination of performance loss in the case of reduced order models. As an example of this possibility we will consider the case when colored system noise is misindentified as a gaussian white noise. The simulated results, for a helicopter in hover, given in the paper indicate that the extra effort expended in parameter identification may not be justified as the optimal trajectory and final performance is practically insensitive to errors in most of the model parameters.

This paper presents a now method of optimal digital PID feedback control for a linear multivariate system by using a, parameter optimization technique. The most difficult points for the design of optimal digital PID feedback control system by the modern control theory are : (1) the control structure of it is specified in advance, (2) unless all the state variables are fed back, the optimal control cannot be obtained by dynamic programming or the maximum principle. However, the optimal digital PID feedback gains are determined by using the parameter optimization technique in this paper. When there are some states which are not fed back in the control system, the optimal feedback gains depend on the initial states. First, the optimal solution is presented in the case where all the initial Btates are known. Next, it is extended to the case where the initial states are random variables and their statistical properties are known,

Aiming at the problem of MIG welding and considering the existing analog control wire feed system has the disadvantages of low response speed, low control accuracy and poor stability. This thesis designs a set of digital control wire feed system based on LPC2132 microprocessor and introduces the control principle of wire feed motor, CAN bus interface circuit and PID control algorithm. Under the condition of power grid voltage fluctuation and load change, we do a lot of experiments. The results show that: the wire feed change rate of designed system is very small, which not only meets the requirements of JB/T-1998.MIG/MAG arc welding standard, but also greatly improves the accuracy and stability of control system.

THE SAMPLING PERIOD AS A CONTROL PARAMETER

Microcontroller(MCF5213CAF80) and FPGA based control system for pulsed MIG welding power source is presented, aiming at some of deficiencies in the control system based on analogous control technology and single-chip control technology, such as poor flexibility, control precision and reliability. The overall hardware circuit scheme, sampling and A/D converter circuits and PWM drive circuits are designed. Then, the software design of FPGA and the software design of real-time embedded operating system μC/OS-II on MCF5213CAF80 are proposed. The experimental results show that the microcontroller and FPGA based control system for pulsed MIG welding power source has the advantages of quicker response, better reliability and more stable arc length.

Design of on-line embedded web server is a challenging part of many embedded and real time data acquisition and control system applications. The World Wide Web is a global system of interconnected computer networks that use the standard Internet Protocol Suite (TCP/IP) to serve billion of users worldwide and allows the user to interface many real time embedded applications like data acquisition, Industrial automations and safety measures etc,. This paper approached towards the design and development of on-line Interactive Data Acquisition and Control System (IDACS) using ARM based embedded web server. It can be a network, intelligent and digital distributed control system. Single chip IDACS method improves the processing capability of a system and overcomes the problem of poor real time and reliability. This system uses ARM9 Processor portability with Real Time Linux operating system (RTLinux RTOS) it makes the system more real time and handling various processes based on multi tasking and reliable scheduling mechanisms. Web server application is ported into an ARM processor using embedded `C' language. Web pages are written by Hyper text markup language (HTML); it is beneficial for real time IDACS, Mission critical applications, ATM networks and more.

In the design of digital control systems, the time delay due to computation time of a processor cannot be often neglected. In this paper, we consider the problem of synthesizing a type-1 optimal digital servosystem taking account of controller delay of one sampling period.It is first shown that the optimal digital servo problem in which a quadratic criterion function is defined for a given continuous-time plant can be reasonably reformulated to a discrete optimal regulator problem. To assure the solvability of this problem, some conditions for the preservation of stabilizability and detectability of the plant under sampling are given. In the discrete optimal regulator problem considered here, not only control input but also the initial state of the servocompensator are referred as free design parameters. The obtained optimal digital control law contains a feedforward term of reference signal in addition to a feedback term. It is also shown that the optimal control law has a function of estimating the state variables at the following sampling period in order to recover the controller delay.

This paper has introduced a design of digital speed control system of permanent magnet brushless DC motor based on MCS-80C196KC.The system use Direct Back-EMF to detect rotor position, and combined with three-start technology to expand the speed control range. Application of Double Closed Loop PID control method to overcome the limitations of conventional control methods, which provide a new way for the design and manufacture of motor and the debug of control systems.

Simulation modeling of nuclear steam generator water level process — a case study

Control Systems Analysis and Design Labs with Educational Plants

The availability of digital MSI and LSI has made digital flight control systems more cost effective than analog systems for all but the simplest systems. The organization of a digital flight control system is concerned not only with implementation of the control laws and associated logic but also with the management of the data used in these computations and the organization of the computation. The configuration taken by a digital flight control system is dominated by the integrity and data handling requirements. This paper considers the impact of these factors on the design and operation of digital flight control systems with particular emphasis on the use of fiber optics for transmission of data between lanes.

It is demonstrated that reconfigurable digital multiple model-following flight control systems incorporating fast-sampling error-actuated digital PID (proportional plus integral plus derivative) controllers can be easily designed using directly measurable input/output data. Thus, for example, it is shown in the case of the F-16 aircraft that desired flying qualities with respect to both pitch-rate and angle-of-attack response characteristics can be simultaneously achieved in the absence of sensor failures. In addition, in the case of failure of the angle-of-attack sensor, it is shown that desired flying qualities with respect to pitch-rate response characteristics and satisfactory flying qualities with respect to angle-of-attack response characteristics can still be achieved by reconfiguring the digital controller. >

Modern High performance control applications demanded from mixed-signal and digital signal processors (DSPs) are ever increasing. As digital circuits and DSP operate at a higher rate, a considerable amount of noise and radiation degrades the system?s performance and creates EMI problems that make it difficult to pass tests required to obtain certification by the EMC regulations. In this paper, we introduce some effective methods for reduced EMI of the measurement and control systems, which are power supply design, clock and phase-locked loop (PLL) isolation, decoupling techniques, digital and analog partitioning, printed circuit board (PCB) layout, and so on for meeting many challenges of mixed-signal and DSP systems design. Design guidelines for improved EMC and signal integrity are derived from the results obtained, thus, the evaluation board of the measurement and control systems is especially suitable for performing function in high definition array induction log (HDAIL).