Theoretical and experimental research on the deconvolution algorithm of dwell time in the technology of computer controlled optical surfacing （CCOS） formation is made to get an ultra-smooth surface of space optical ...Theoretical and experimental research on the deconvolution algorithm of dwell time in the technology of computer controlled optical surfacing （CCOS） formation is made to get an ultra-smooth surface of space optical element. Based on the Preston equation, the convolution model of CCOS is deduced. Considering the morbidity problem of deconvolution algorithm and the actual situation of CCOS technology, the weighting spatial deconvolution algorithm is presented based on the non-periodic matrix model, which avoids solving morbidity resulting from the noise induced by measurement error. The discrete convolution equation is solved using conjugate gradient iterative method and the workload of iterative calculation in spatial domain is reduced effectively. Considering the edge effect of convolution algorithm, the method adopts a marginal factor to control the edge precision and attains a good effect. The simulated processing test shows that the convergence ratio of processed surface shape error reaches 80%. This algorithm is further verified through an experiment on a numerical control bonnet polishing machine, and an ultra- smooth glass surface with the root-mean-square （RMS） error of 0.0088 tim is achieved. The simulation and experimental results indicate that this algorithm is steady, convergent, and precise, and it can satisfy the solving requirement of actual dwell time.展开更多
Aimed at the welding ttechnological requirements of foe missile shell,a computer control system for automatic TIG welding of aluminium alloy sheets has been developed in this paper.The hardware of the system is compos...Aimed at the welding ttechnological requirements of foe missile shell,a computer control system for automatic TIG welding of aluminium alloy sheets has been developed in this paper.The hardware of the system is composed of the four sub-systems,i.e.weldingpower source,arc length controller,welding wire feeder and welding head traveller.The software of the system comprises the on-line executing program and the off-line serving program.The operating principle,specifications and control of the system are introduced.The experiments indicate that the system possesses rational hardware structure and practical software function,and has solved the problem of high frequency interference to the computer control system. Therefore,the control system can satisfy the requirements of automatic TIG welding of the missile shell.展开更多
Computer simulation researches on Direct Torque Control System (DTC) are to be done. That fact is demonstrated:at high speed,the operating property of an induction motor is very good,almost the same as fieldoriented c...Computer simulation researches on Direct Torque Control System (DTC) are to be done. That fact is demonstrated:at high speed,the operating property of an induction motor is very good,almost the same as fieldoriented control system fat low speed (for example: below 2-3Hz), the operating property of a motor is getting worse,and the stator resistance R1 of the motor must be compensated. If compensation precision gets 5 %,the operating property of the motor will be greatly improved.展开更多
This paper provides a mathematical model for the billet reheating process in furnace.A new optimum method is brought up that the objective function is the integral value of enthalpy increasing process of a billet.Diff...This paper provides a mathematical model for the billet reheating process in furnace.A new optimum method is brought up that the objective function is the integral value of enthalpy increasing process of a billet.Different delays are simulated and calculated,some proper delay strategies are ob- tained.The on-line computer control model is de- veloped.The real production conditions simulated, the temperature deviation of drop out billet from the target temperature is kept within±15℃.展开更多
An automatic control system for the electrostatic accelerator has been developed by adopting the PLC （Programmable Logic Controller） control technique, infrared and optical-fibre transmission technique and network c...An automatic control system for the electrostatic accelerator has been developed by adopting the PLC （Programmable Logic Controller） control technique, infrared and optical-fibre transmission technique and network communication with the purpose to improve the intelligence level of the accelerator and to enhance the ability of monitoring, collecting and recording parameters. In view of the control system＇ structure, some anti-interference measures have been adopted after analyzing the interference sources. The measures in hardware include controlling the position of the corona needle, using surge arresters, shielding, ground connection and stabilizing the voltage. The measures in terms of software involve inter-blocking protection, soft-spacing, time delay, and diagnostic and protective programs. The electromagnetic compatible ability of the control system has thus been effectively improved.展开更多
In this paper, a real-time computation method for the control problems in differential-algebraic systems is presented. The errors of the method are estimated, and the relation between the sampling stepsize and the con...In this paper, a real-time computation method for the control problems in differential-algebraic systems is presented. The errors of the method are estimated, and the relation between the sampling stepsize and the controlled errors is analyzed. The stability analysis is done for a model problem, and the stability region is ploted which gives the range of the sampling stepsizes with which the stability of control process is guaranteed.展开更多
Based on the suitably defined multivariable version of Kranc operators and the extended input and output vectors, the multirate sampling plant is transformed to a equivalent time invariant single rate one, then the t...Based on the suitably defined multivariable version of Kranc operators and the extended input and output vectors, the multirate sampling plant is transformed to a equivalent time invariant single rate one, then the transfer function model of the multivariable multirate sampling plant is obtained. By combining this plant model with the time invariant description of the multirate controller in terms of extended vectors, the closed loop transfer function model of the multirate feedback control system can be determinated. This transfer function model has a very simple structure, and can be used as a basis for the analysis and synthesis of the multirate sampling feedback control systems in the frequency domain.展开更多
基金supported by the National "863" Program of China
文摘Theoretical and experimental research on the deconvolution algorithm of dwell time in the technology of computer controlled optical surfacing （CCOS） formation is made to get an ultra-smooth surface of space optical element. Based on the Preston equation, the convolution model of CCOS is deduced. Considering the morbidity problem of deconvolution algorithm and the actual situation of CCOS technology, the weighting spatial deconvolution algorithm is presented based on the non-periodic matrix model, which avoids solving morbidity resulting from the noise induced by measurement error. The discrete convolution equation is solved using conjugate gradient iterative method and the workload of iterative calculation in spatial domain is reduced effectively. Considering the edge effect of convolution algorithm, the method adopts a marginal factor to control the edge precision and attains a good effect. The simulated processing test shows that the convergence ratio of processed surface shape error reaches 80%. This algorithm is further verified through an experiment on a numerical control bonnet polishing machine, and an ultra- smooth glass surface with the root-mean-square （RMS） error of 0.0088 tim is achieved. The simulation and experimental results indicate that this algorithm is steady, convergent, and precise, and it can satisfy the solving requirement of actual dwell time.
文摘Aimed at the welding ttechnological requirements of foe missile shell,a computer control system for automatic TIG welding of aluminium alloy sheets has been developed in this paper.The hardware of the system is composed of the four sub-systems,i.e.weldingpower source,arc length controller,welding wire feeder and welding head traveller.The software of the system comprises the on-line executing program and the off-line serving program.The operating principle,specifications and control of the system are introduced.The experiments indicate that the system possesses rational hardware structure and practical software function,and has solved the problem of high frequency interference to the computer control system. Therefore,the control system can satisfy the requirements of automatic TIG welding of the missile shell.
文摘Computer simulation researches on Direct Torque Control System (DTC) are to be done. That fact is demonstrated:at high speed,the operating property of an induction motor is very good,almost the same as fieldoriented control system fat low speed (for example: below 2-3Hz), the operating property of a motor is getting worse,and the stator resistance R1 of the motor must be compensated. If compensation precision gets 5 %,the operating property of the motor will be greatly improved.
文摘This paper provides a mathematical model for the billet reheating process in furnace.A new optimum method is brought up that the objective function is the integral value of enthalpy increasing process of a billet.Different delays are simulated and calculated,some proper delay strategies are ob- tained.The on-line computer control model is de- veloped.The real production conditions simulated, the temperature deviation of drop out billet from the target temperature is kept within±15℃.
基金the special fund of the Education Department of Henan Provice
文摘An automatic control system for the electrostatic accelerator has been developed by adopting the PLC （Programmable Logic Controller） control technique, infrared and optical-fibre transmission technique and network communication with the purpose to improve the intelligence level of the accelerator and to enhance the ability of monitoring, collecting and recording parameters. In view of the control system＇ structure, some anti-interference measures have been adopted after analyzing the interference sources. The measures in hardware include controlling the position of the corona needle, using surge arresters, shielding, ground connection and stabilizing the voltage. The measures in terms of software involve inter-blocking protection, soft-spacing, time delay, and diagnostic and protective programs. The electromagnetic compatible ability of the control system has thus been effectively improved.
文摘In this paper, a real-time computation method for the control problems in differential-algebraic systems is presented. The errors of the method are estimated, and the relation between the sampling stepsize and the controlled errors is analyzed. The stability analysis is done for a model problem, and the stability region is ploted which gives the range of the sampling stepsizes with which the stability of control process is guaranteed.
文摘Based on the suitably defined multivariable version of Kranc operators and the extended input and output vectors, the multirate sampling plant is transformed to a equivalent time invariant single rate one, then the transfer function model of the multivariable multirate sampling plant is obtained. By combining this plant model with the time invariant description of the multirate controller in terms of extended vectors, the closed loop transfer function model of the multirate feedback control system can be determinated. This transfer function model has a very simple structure, and can be used as a basis for the analysis and synthesis of the multirate sampling feedback control systems in the frequency domain.
