It is a fact that the feedback delay actually arises in digital control systems. It is necessary to modify the structure of digital control systems and develop new control algorithms, which is done in this paper. A gr...It is a fact that the feedback delay actually arises in digital control systems. It is necessary to modify the structure of digital control systems and develop new control algorithms, which is done in this paper. A great number of digital computer simulation experiments have shown the obvious advantage of the new algorithms.展开更多
This paper proposes a separated trajectory tracking controller for fishing ships at sea state level 6 to solve the trajectory tracking problem of a fishing ship in a 6-level sea state,and to adapt to different working...This paper proposes a separated trajectory tracking controller for fishing ships at sea state level 6 to solve the trajectory tracking problem of a fishing ship in a 6-level sea state,and to adapt to different working environments and safety requirements.The nonlinear feedback method is used to improve the closed-loop gain shaping algorithm.By introducing the sine function,the problem of excessive control energy of the system can be effectively solved.Moreover,an integral separation design is used to solve the influence of the integral term in conventional PID controllers on the transient performance of the system.In this paper,a common 32.98 m large fiberglass reinforced plastic(FRP)trawler is adopted for simulation research at the winds scale of Beaufort No.7.The results show that the track error is smaller than 3.5 m.The method is safe,feasible,concise and effective and has popularization value in the direction of fishing ship trajectory tracking control.This method can be used to improve the level of informatization and intelligence of fishing ships.展开更多
In this paper, a pure digital control method for the outer axis of a three-axis flight simulation table is worked out and a state observer is used to obtain the acceleration signal. The method is simple and easy to be...In this paper, a pure digital control method for the outer axis of a three-axis flight simulation table is worked out and a state observer is used to obtain the acceleration signal. The method is simple and easy to be emplayed, and especially suitable for the electrohydraulic (?)ervo-system with fast response. The simulation results show that the system given in this paper has optimal three-order system performance.展开更多
Ultra-compact serpentine inlet faces serve inlet-engine compatibility issues due to flow distortion.To ensure inlet-engine compatibility over a wide range of Mach number,novel active flow control techniques with the a...Ultra-compact serpentine inlet faces serve inlet-engine compatibility issues due to flow distortion.To ensure inlet-engine compatibility over a wide range of Mach number,novel active flow control techniques with the ability of being opened or adjusted as needed draw many attentions in recent years.In this paper,a feedback control system was developed based on the method of microjet blowing.The proposed system includes a pressure adjusting valve to adjust the control effort,a dynamic pressure sensor to sense the inlet distortion intensity,a signal processing instrument to calculate the Root-Mean-Squared(RMS)pressure,and a controller to implement feedback control.To achieve high quality closed-loop controls at dynamic conditions,a novel nondimensional feedback method was developed.The advantage of this nondimensional method was validated at both off-design and arbitrarily changing Mach number conditions.With a sectional PI control law,the RMS control error reduced more than 56%at arbitrary changing conditions.Works in this paper also showed that the dynamics of this nondimensional system can be simplified as a stable second-order overdamped system.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
Least mean square (LMS) decision feedback equalizer (DFE) is preferred as an effective solution to coping with inter-symbol interference (ISI) for ATSC digital television (DTV) receivers. In DTV transmission environme...Least mean square (LMS) decision feedback equalizer (DFE) is preferred as an effective solution to coping with inter-symbol interference (ISI) for ATSC digital television (DTV) receivers. In DTV transmission environment, echo delay often covers several hundreds symbols, which leads to very large-scale equalizer. One consequence of the large-scale equalizer is the very slow convergence, which combined with error propagation, inherent drawback of DFE, seriously deteriorates the performance of the receivers, especially in severe channels More working modes and corresponding robust control mechanism were given to help the equalizer converge to the stable state smoothly. Simulation results show that the improved equalizer can perform better, especially in the severe channels.展开更多
A low-power, configurable auto-gain control loop for a digital hearing aid system on a chip （SoC） is presented. By adopting a mixed-signal feedback control structure and peak detection and judgment, it can work in a...A low-power, configurable auto-gain control loop for a digital hearing aid system on a chip （SoC） is presented. By adopting a mixed-signal feedback control structure and peak detection and judgment, it can work in automatic gain or variable gain control modes through a digital signal processing unit. A noise-reduction and dynamic range （DR） improvement technique is also used to ensure the DR of the circuit in a low-voltage supply. The circuit is implemented in an SMIC 0.13 μm 1P8M CMOS process. The measurement results show that in a I V power supply, 1.6 kHz input frequency and 200 mVp-p, the SFDR is 74.3 dB, the THD is 66.1 dB, and the total power is 89 μW, meeting the application requirements of hearing aid SoCs.展开更多
Deformable mirrors are essential dynamic wavefront compensation.Among the various types of deformable mirrors with different actuation mechanisms,the unimorph piezoelectric deformable mirror(UPDM)offers distinct advan...Deformable mirrors are essential dynamic wavefront compensation.Among the various types of deformable mirrors with different actuation mechanisms,the unimorph piezoelectric deformable mirror(UPDM)offers distinct advantages owing to its compact size and low cost.The two most critical challenges in UPDM are electrode fabrication and deformation control.This study proposes an integrated electrode fabrication and sensorless feedback control scheme for UPDM,which simplifies the manufacturing process and enhances its performance.The electrode array is created using silkscreen printing combined with flexible printed circuit board technology,integrating electrode fabrication and electrical connection into a single step.The desired mirror deformation is achieved by introducing a closed-loop direct deformation control method based on piezoelectric self-sensing.The feedback mechanism utilizes the local strain-induced charge generated by the piezoelectric plate,effectively addressing the nonlinear behavior of the piezoelectric material.Experimental results confirm the feasibility and effectiveness of the proposed method,with the maximum relative error in the steady state phase remaining below 2%.展开更多
文摘It is a fact that the feedback delay actually arises in digital control systems. It is necessary to modify the structure of digital control systems and develop new control algorithms, which is done in this paper. A great number of digital computer simulation experiments have shown the obvious advantage of the new algorithms.
基金supported by Liaoning Provincial Department of Education 2023 Basic Research Projects for Universities and Colleges(Grant No.JYTQN2023131)Liaoning Provincial Science and Technology Program:Cooperative Control and Recognition of Unmanned Vessels for Fishing Vessel Operation Scenarios(Grant No.600024003)Liaoning Provincial Department of Education Scientific Research Funding Project(Grant No.LJKZ0726).
文摘This paper proposes a separated trajectory tracking controller for fishing ships at sea state level 6 to solve the trajectory tracking problem of a fishing ship in a 6-level sea state,and to adapt to different working environments and safety requirements.The nonlinear feedback method is used to improve the closed-loop gain shaping algorithm.By introducing the sine function,the problem of excessive control energy of the system can be effectively solved.Moreover,an integral separation design is used to solve the influence of the integral term in conventional PID controllers on the transient performance of the system.In this paper,a common 32.98 m large fiberglass reinforced plastic(FRP)trawler is adopted for simulation research at the winds scale of Beaufort No.7.The results show that the track error is smaller than 3.5 m.The method is safe,feasible,concise and effective and has popularization value in the direction of fishing ship trajectory tracking control.This method can be used to improve the level of informatization and intelligence of fishing ships.
文摘In this paper, a pure digital control method for the outer axis of a three-axis flight simulation table is worked out and a state observer is used to obtain the acceleration signal. The method is simple and easy to be emplayed, and especially suitable for the electrohydraulic (?)ervo-system with fast response. The simulation results show that the system given in this paper has optimal three-order system performance.
基金supported by the National Natural Science Foundation of China (No.11602291)。
文摘Ultra-compact serpentine inlet faces serve inlet-engine compatibility issues due to flow distortion.To ensure inlet-engine compatibility over a wide range of Mach number,novel active flow control techniques with the ability of being opened or adjusted as needed draw many attentions in recent years.In this paper,a feedback control system was developed based on the method of microjet blowing.The proposed system includes a pressure adjusting valve to adjust the control effort,a dynamic pressure sensor to sense the inlet distortion intensity,a signal processing instrument to calculate the Root-Mean-Squared(RMS)pressure,and a controller to implement feedback control.To achieve high quality closed-loop controls at dynamic conditions,a novel nondimensional feedback method was developed.The advantage of this nondimensional method was validated at both off-design and arbitrarily changing Mach number conditions.With a sectional PI control law,the RMS control error reduced more than 56%at arbitrary changing conditions.Works in this paper also showed that the dynamics of this nondimensional system can be simplified as a stable second-order overdamped system.
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.
基金The National Natural Science Foundation of China (No. 603320307)
文摘Least mean square (LMS) decision feedback equalizer (DFE) is preferred as an effective solution to coping with inter-symbol interference (ISI) for ATSC digital television (DTV) receivers. In DTV transmission environment, echo delay often covers several hundreds symbols, which leads to very large-scale equalizer. One consequence of the large-scale equalizer is the very slow convergence, which combined with error propagation, inherent drawback of DFE, seriously deteriorates the performance of the receivers, especially in severe channels More working modes and corresponding robust control mechanism were given to help the equalizer converge to the stable state smoothly. Simulation results show that the improved equalizer can perform better, especially in the severe channels.
基金supported by the Chinese National Science and Technology Expertise Program(No.Y1GZ212001)
文摘A low-power, configurable auto-gain control loop for a digital hearing aid system on a chip （SoC） is presented. By adopting a mixed-signal feedback control structure and peak detection and judgment, it can work in automatic gain or variable gain control modes through a digital signal processing unit. A noise-reduction and dynamic range （DR） improvement technique is also used to ensure the DR of the circuit in a low-voltage supply. The circuit is implemented in an SMIC 0.13 μm 1P8M CMOS process. The measurement results show that in a I V power supply, 1.6 kHz input frequency and 200 mVp-p, the SFDR is 74.3 dB, the THD is 66.1 dB, and the total power is 89 μW, meeting the application requirements of hearing aid SoCs.
基金supported in part by the Strategic Priority Research Program of the Chinese Academy of Sciences(XDB1050000)in part by the CAS Project for Young Scientists in Basic Research(YSBR-066)+2 种基金in part by the National Science Foundation of China(T2122001)in part by the capital construction funds within the budget of Jilin Province(2023C030-6)in part by the Youth Innovation Promotion Association of the Chinese Academy of Sciences(Y2021065).
文摘Deformable mirrors are essential dynamic wavefront compensation.Among the various types of deformable mirrors with different actuation mechanisms,the unimorph piezoelectric deformable mirror(UPDM)offers distinct advantages owing to its compact size and low cost.The two most critical challenges in UPDM are electrode fabrication and deformation control.This study proposes an integrated electrode fabrication and sensorless feedback control scheme for UPDM,which simplifies the manufacturing process and enhances its performance.The electrode array is created using silkscreen printing combined with flexible printed circuit board technology,integrating electrode fabrication and electrical connection into a single step.The desired mirror deformation is achieved by introducing a closed-loop direct deformation control method based on piezoelectric self-sensing.The feedback mechanism utilizes the local strain-induced charge generated by the piezoelectric plate,effectively addressing the nonlinear behavior of the piezoelectric material.Experimental results confirm the feasibility and effectiveness of the proposed method,with the maximum relative error in the steady state phase remaining below 2%.
