摘要:

AbstractThe paper deals with the modelling and simulation of industrial robots. To find the best possible control system for robots which were made in our department, corresponding model hod to be developed. Because of complexity and nonlinearity of a real construction, our model is limited to a single kinematic stage. So we do not consider its multivariable character. The model gives information about arm position, speed and pressure in hydraulic cylinder. It includes linear servovalve, hidraulic cylinder, displacement sensor and controller. Saturation and delay of the servovalve, flow modulation by the pressure, compressibility and leakage of fluid are also considered. The characteristic feotures of the positioning system were determined by means of hybrid simulation. In the paper some possibilities for model simplifications neglecting information about speed and pressure are dicussed. Some local control lows are presented together with a comparison of analog and digital controllers. It was established that the main problem in analog robot control is to choose the right gain (no'llinearity). Satisfactory results were obtained with digital controllers, which change their control low or parameters depending on movement direction or error magnitude. 80th point-to-piont and continuous-path control are studied and illustrated by the simulation results.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759798

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

AbstractAs a central part of an interactive colour-display core-surveillance system for giving an operator a better insight into the present and future operational status of a PWR, a 3-D real-time nonlinear digital core and plant simulator GARLIC has been developed.The simulated PWR is assumed to consist of a core, a natural circulation U-tube steam generator and a main steam system. By computing the distribution of important local core parameters (power, xenon and iodine densities, fuel rod and coolant temperatures etc.) and the behaviour of global plant parameters (system pressure, water level, inlet and outlet temperatures) as a function of both inherent core dynamics and external actions or disturbances during long range (quasistationary) transients, GARLIC can be used in a predictive mode. The results of transient computations are stored in a database and displayed on colour terminals using an interactive system.The main assumptions and restrictions used to develop the theoretical model as well as the main characteristics, properties and requirements of the code are reviewed and results of transient runs on a process computer are presented.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759799

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

AbstractAs a result of increasing demands for controllability in conjunction with efficiency, pressure compensated systems are gaining an ever increasing recognition. In this perspective the present paper delineates the mathematical modelling of a single actuator pressure compensated system with emphasis on Its mobile applications and implications thereof. The overall system behaviour is investigated in light of its controllability features and dynamic analyses that are illustrated are grounded on the use of the Gear integration algorithm.In reducing the magnitude and number of pressure cycles that interconnecting lines must withstand, the study aims at analysing and bringing to proper evidence the diversified influence of Key parameters on system transients. Peculiarities and possible weak points of the pressure compensated system are detailed and some Interest is also de-voted to feasible design optimization aspects.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759800

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

AbstractInjection moulding is one of the most im-portant processes in plastics industries, since metal components are increasingly displaced by precision mouldings in all fields of application. Precision moulding necessitates both detailed processing know-how and sophisticated process control and therefore calls for specific modelling.The paper discusses the application of system analysis to injection moulding. In contrast to well-known methods of theoretical modelling which aims at more insight into physical phenomena, stress is laid upon experimental modelling. This way of system analysis through identification is employed to set up mathematical models to be used in control systems.For this purpose the models must be as simple as possible, thus offering the possibility of on-line adaptation to varied process operating conditions. Examples of identification are given, showing results of injection stage modelling and of production cycle modelling.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759801

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

AbstractA modern high speed bottling line is a complex sy3tem comprising a multiple of different machines connected by conveyors.Machine failures cannot be avoided in such a line; however, the buffer capacities of the conveyors together with an adequate control system for the speed of machines and conveyors will minimize the effect of small failures on the output of other machines. The objective of our investigation was the development of models at several levels of aggregation, that will simulate the performance of bottling lines.Nowadays these models serve as a powerful tool to predict the effect of modifications on the overall efficiency of existing lines, as well as for the design of new lines.This article explains how the models are built, using PROSIM, a modelling language for combined discrete/continuous simulation. Furthermore, it covers the application of these models with the emphasis on a special information system, that collects data about machine stops.This computerised data collection system is required for the following reasons:- collection of accurate input data for the simulation experiments,- collection of data for model validation,- monitoring of bottling line efficiencies.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759802

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

AbstractHydraulic cylinders must often be synchronized in fluid power systems. For example, control of lift platforms, control of aircraft's wing flaps and wave generator flaps. Synchronization might be possible using control principles based on hydraulic flow dividers or hydraulic flow control valves. This paper deals with the optimum design of synchronized hydraulic cylinders using closed servo loop principles with electrohydrau-lic servo valves.The master-slave principle and two new deve-loped principles are modelled and investigated by simulation. The first of the new principle is an improved master-slave system using position difference feedback and velocity difference feedback. Furthermore this control system is studied when an acceleration difference loop is added. The other one is a modified master-slave system using position difference feedback and velocity feedforward.In order to analyse the properties of the different control principles mathematical models are developed and programmed in IBM-CSMP (Conti-nuous System Modelling Program). Computer simu-lations are carried out to study the parameter sensitivities and the dynamic behaviour of the regarded control principles.Results obtained from simulations and design basis are presented and discussed.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759803

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

AbstractAlthough numerous knee joint prostheses have been designed their in vivo articulation is often deficient and excessive wear and failure of the implant can occur. The articulation characteristics depend upon the accuracy of surgical fixation of the prosthetic components and a theoretical model, using 'digital' computation has been developed to optimise the initial alignment of the components so that the desired articulation can be obtained.An analytical planar method for normal knee movement has been developed from work published by Gunston. An analytical model of the femoral component of the knee prosthesis under investigation is then formulated in which the positional alignment of this component relative to its tibial component is represented by 6 degrees of freedom. The spatial contact positions of the femoral component relative to its tibial component are then calculated during sutlsequent modelled motion of the implanted knee, taking the Gunston "motion" as standard, and the clearance/interference pattern between the prosthetic components quantified. The initial relative positions of the tibial and femoral component were varied within the confines of the normal knee geometry and using the clearance/interference data the optimal initial alignment of a number of prosthetic component dimensions is presented. The subsequent wear of the prostheses and the danger of loosening should be reduced if this optimal alignment of components is obtained at surgery.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759804

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759805

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor

摘要:

AbstractThe paper describee experimental modelling and optimal control studies of a microalternator system. State-space and input/output models are obtained in discrete-time, using least-squares identification. Based on these models state feedback and output feedback optimal controllers are designed. The controllers are tested on-line and shown to perform very well over a wide range of operating conditions.

ISSN:0228-6203    

DOI:10.1080/02286203.1982.11759806

出版商:Taylor&Francis    

年代:1982

数据来源: Taylor