This paper presents an LC VCO with auto-amplitude control （AAC）, in which pMOS FETs are used,and the varactors are directly connected to ground to widen the linear range of Kvco. The AAC circuitry adds little noise ...This paper presents an LC VCO with auto-amplitude control （AAC）, in which pMOS FETs are used,and the varactors are directly connected to ground to widen the linear range of Kvco. The AAC circuitry adds little noise to the VCO but provides it with robust performance over a wide temperature and carrier frequency range.The VCO is fabricated in a chartered 50GHz 0.35μm SiGe BiCMOS process. The measurements show that it has - 127. 27dBc/Hz phase noise at 1MHz offset and a linear gain of 32.4MHz/V between 990MHz and 1.14GHz.The whole circuit draws 6. 6mA current from 5V supply.展开更多
PID controllers were used for the hydraulic servo system of sliding gate and the tundish weight control system in continuous caster.These two loops were synthesized in mould level controller based on model reduction a...PID controllers were used for the hydraulic servo system of sliding gate and the tundish weight control system in continuous caster.These two loops were synthesized in mould level controller based on model reduction and internal model control strategy.Satisfactory control performance of this synthetic mould level controller was demonstrated by simulations and on-line experiments.展开更多
High signal-to-noise ratio can be achieved with the electron multiplying charge-coupled-device（EMCCD） applied in the Shack–Hartmann wavefront sensor（S–H WFS） in adaptive optics（AO）.However,when the brightness ...High signal-to-noise ratio can be achieved with the electron multiplying charge-coupled-device（EMCCD） applied in the Shack–Hartmann wavefront sensor（S–H WFS） in adaptive optics（AO）.However,when the brightness of the target changes in a large scale,the fixed electron multiplying（EM） gain will not be suited to the sensing limitation.Therefore an auto-gain-control method based on the brightness of light-spots array in S–H WFS is proposed in this paper.The control value is the average of the maximum signals of every light spot in an array,which has been demonstrated to be kept stable even under the influence of some noise and turbulence,and sensitive enough to the change of target brightness.A goal value is needed in the control process and it is predetermined based on the characters of EMCCD.Simulations and experiments have demonstrated that this auto-gain-control method is valid and robust,the sensing SNR reaches the maximum for the corresponding signal level,and especially is greatly improved for those dim targets from 6 to 4 magnitude in the visual band.展开更多
A new auto tuning procedure for PI/D controller based on phase and amplitude margin specifications was proposed.The procedure applied a modified relay feedback experiment to identifying the process frequency response ...A new auto tuning procedure for PI/D controller based on phase and amplitude margin specifications was proposed.The procedure applied a modified relay feedback experiment to identifying the process frequency response of the point where the Nyquist curve intersects the negative imaginary axis,and the PI/D controller settings can be obtained based on this single point.The auto tuning method has all the merits of the tuning method that Astrom and Hagglund had proposed,and overcomes its problems.The simulation results show that the proposed tuning method has better performance than Astrom Hagglund’s tuning method.展开更多
This paper presents a control strategy for maglev system based on the sliding mode controller with auto-tuning law. The designed adaptive controller will replace the conventional sliding mode control (SMC) to eliminat...This paper presents a control strategy for maglev system based on the sliding mode controller with auto-tuning law. The designed adaptive controller will replace the conventional sliding mode control (SMC) to eliminate the chattering resulting from the SMC. The stability of maglev system is ensured based on the Lyapunov theory. Simulation results verify the effectiveness of the proposed method. In addition, the advantages of the proposed controller are indicated in comparison with a traditional sliding mode controller.展开更多
The polynomial matrix using the block coefficient matrix representation auto-regressive moving average(referred to as the PM-ARMA)model is constructed in this paper for actively controlled multi-degree-of-freedom(MDOF...The polynomial matrix using the block coefficient matrix representation auto-regressive moving average(referred to as the PM-ARMA)model is constructed in this paper for actively controlled multi-degree-of-freedom(MDOF)structures with time-delay through equivalently transforming the preliminary state space realization into the new state space realization.The PM-ARMA model is a more general formulation with respect to the polynomial using the coefficient representation auto-regressive moving average(ARMA)model due to its capability to cope with actively controlled structures with any given structural degrees of freedom and any chosen number of sensors and actuators.(The sensors and actuators are required to maintain the identical number.)under any dimensional stationary stochastic excitation.展开更多
文摘This paper presents an LC VCO with auto-amplitude control （AAC）, in which pMOS FETs are used,and the varactors are directly connected to ground to widen the linear range of Kvco. The AAC circuitry adds little noise to the VCO but provides it with robust performance over a wide temperature and carrier frequency range.The VCO is fabricated in a chartered 50GHz 0.35μm SiGe BiCMOS process. The measurements show that it has - 127. 27dBc/Hz phase noise at 1MHz offset and a linear gain of 32.4MHz/V between 990MHz and 1.14GHz.The whole circuit draws 6. 6mA current from 5V supply.
文摘PID controllers were used for the hydraulic servo system of sliding gate and the tundish weight control system in continuous caster.These two loops were synthesized in mould level controller based on model reduction and internal model control strategy.Satisfactory control performance of this synthetic mould level controller was demonstrated by simulations and on-line experiments.
基金Project supported by the National Natural Science Foundation of China(Grant Nos.11174274,61205021,and 61405194)the State Key Laboratory of Applied Optics,Changchun Institute of Optics,Fine Mechanics and Physics,Chinese Academy of Sciences
文摘High signal-to-noise ratio can be achieved with the electron multiplying charge-coupled-device（EMCCD） applied in the Shack–Hartmann wavefront sensor（S–H WFS） in adaptive optics（AO）.However,when the brightness of the target changes in a large scale,the fixed electron multiplying（EM） gain will not be suited to the sensing limitation.Therefore an auto-gain-control method based on the brightness of light-spots array in S–H WFS is proposed in this paper.The control value is the average of the maximum signals of every light spot in an array,which has been demonstrated to be kept stable even under the influence of some noise and turbulence,and sensitive enough to the change of target brightness.A goal value is needed in the control process and it is predetermined based on the characters of EMCCD.Simulations and experiments have demonstrated that this auto-gain-control method is valid and robust,the sensing SNR reaches the maximum for the corresponding signal level,and especially is greatly improved for those dim targets from 6 to 4 magnitude in the visual band.
文摘A new auto tuning procedure for PI/D controller based on phase and amplitude margin specifications was proposed.The procedure applied a modified relay feedback experiment to identifying the process frequency response of the point where the Nyquist curve intersects the negative imaginary axis,and the PI/D controller settings can be obtained based on this single point.The auto tuning method has all the merits of the tuning method that Astrom and Hagglund had proposed,and overcomes its problems.The simulation results show that the proposed tuning method has better performance than Astrom Hagglund’s tuning method.
文摘This paper presents a control strategy for maglev system based on the sliding mode controller with auto-tuning law. The designed adaptive controller will replace the conventional sliding mode control (SMC) to eliminate the chattering resulting from the SMC. The stability of maglev system is ensured based on the Lyapunov theory. Simulation results verify the effectiveness of the proposed method. In addition, the advantages of the proposed controller are indicated in comparison with a traditional sliding mode controller.
基金The project supported by the National Natural Science Foundation of China(50278054)
文摘The polynomial matrix using the block coefficient matrix representation auto-regressive moving average(referred to as the PM-ARMA)model is constructed in this paper for actively controlled multi-degree-of-freedom(MDOF)structures with time-delay through equivalently transforming the preliminary state space realization into the new state space realization.The PM-ARMA model is a more general formulation with respect to the polynomial using the coefficient representation auto-regressive moving average(ARMA)model due to its capability to cope with actively controlled structures with any given structural degrees of freedom and any chosen number of sensors and actuators.(The sensors and actuators are required to maintain the identical number.)under any dimensional stationary stochastic excitation.
