A universal locking model for single ion optical clocks was built based on a simple integrator and a double integrator.Different integrator algorithm parameters have been analyzed in both numerical simulations and exp...A universal locking model for single ion optical clocks was built based on a simple integrator and a double integrator.Different integrator algorithm parameters have been analyzed in both numerical simulations and experiments.The frequency variation measured by the comparison of two optical clocks coincides well with the simulation results for different second integrator parameters.According to the experimental results,the sensitivity of the servo error influenced by laser frequency drift with the addition of a double integrator was suppressed by a factor of 107.In a week-long comparison of optical clocks,the relative uncertainty of the servo error is determined to be 1.9×10^(-18),which is meaningful for the systematic uncertainty of the transportable single^(40)Ca^(+)ion optical clock entering the 10^(-18)level.展开更多
A technology of two-coordinate dual-servo(TCDS) is proposed. Using this technology which is based on error compensation, workpieces of higher contour accuracy could he turned on ultra-precision machine tool with Poor ...A technology of two-coordinate dual-servo(TCDS) is proposed. Using this technology which is based on error compensation, workpieces of higher contour accuracy could he turned on ultra-precision machine tool with Poor dynamic performances. The principle, constitute and operation of a TCDS system are described. Mathematical proof and experiments are achieved in addition.展开更多
Flight simulator is an important device and a typical high performanceposition servo system used in the hardware-in-the-loop simulation of flight control system. Withoutusing the future desired output, zero phase erro...Flight simulator is an important device and a typical high performanceposition servo system used in the hardware-in-the-loop simulation of flight control system. Withoutusing the future desired output, zero phase error controller makes the overall system's frequencyresponse exhibit zero phase shift for all frequencies and a very small gain error at low frequencyrange can be achieved. A new algorithm to design the feed forward controller is presented, in orderto reduce the phase error, the design of proposed feed forward controller uses a modified plantmodel, which is a closed loop transfer function, through which the system tracking precisionperformance can be improved greatly. Real-time control results show the effectiveness of theproposed approach in flight simulator servo system.展开更多
Using the future desired input value, zero phase error controller enables the overall system＇s frequency response exhibit zero phase shift for all frequencies and a small gain error at low frequency range, and based ...Using the future desired input value, zero phase error controller enables the overall system＇s frequency response exhibit zero phase shift for all frequencies and a small gain error at low frequency range, and based on this, a new algorithm is presented to design the feedforward controller. However, zero phase error controller is only suitable for certain linear system. To reduce the tracking error and improve robustness, the design of the proposed feedforward controller uses a neural compensation based on diagonal recurrent neural network. Simulation and real-time control results for flight simulator servo system show the effectiveness of the proposed approach.展开更多
为实现多轴伺服驱动压力机的同步控制,文章基于传统偏差耦合控制提出一种虚拟轴改进型偏差耦合同步控制方法,并搭建同步控制实验平台进行现场验证。基于压力机结构和控制模型实现模糊比例积分微分(proportional integral derivative,PID...为实现多轴伺服驱动压力机的同步控制,文章基于传统偏差耦合控制提出一种虚拟轴改进型偏差耦合同步控制方法,并搭建同步控制实验平台进行现场验证。基于压力机结构和控制模型实现模糊比例积分微分(proportional integral derivative,PID)位置跟踪控制;在传统偏差耦合控制结构中添加评价误差模块,搭建一种改进型偏差耦合同步控制方法,提高同步系统的抗扰动能力和同步精度;将虚拟轴引入改进型偏差耦合控制结构中,从而解除多轴间的直接耦合关系,简化改进型同步位移补偿结构。实验结果表明,该方法有效提高了压力机同步抗扰动能力和稳态同步精度。展开更多
In order to improve the measurement-precision of the gyro,the gyro experiment is completed based on gyro servo technology.The error sources of gyro servo technology are analyzed in the process of measurement,and the i...In order to improve the measurement-precision of the gyro,the gyro experiment is completed based on gyro servo technology.The error sources of gyro servo technology are analyzed in the process of measurement,and the impact of these error sources on measurement is evaluated.To eliminate interference signal existing in the sampled data of the measurement,a modified wavelet threshold filtering method is presented.The results of the simulation and measurement show that the estimation-precision of the proposed method is improvement remarkably compared with the fast Fourier transform method,and the calculation work is reduced compared with the conventional wavelet threshold filtering methods,furthermore,the phenomenon of a common threshold of ＂killing＂ is solved thoroughly.展开更多
High-speed pick-and-place parallel robot is a system where the inertia imposed on the motor shafts is real-time changing with the system configurations.High quality of computer control with proper controller parameter...High-speed pick-and-place parallel robot is a system where the inertia imposed on the motor shafts is real-time changing with the system configurations.High quality of computer control with proper controller parameters is conducive to overcoming this problem and has a significant effect on reducing the robot＇s tracking error.By taking Delta robot as an example,a method for parameter tuning of the fixed gain motion controller is presented.Having identifying the parameters of the servo system in the frequency domain by the sinusoidal excitation,the PD＋feedforward control strategy is proposed to adapt to the varying inertia loads,allowing the controller parameters to be tuned by minimizing the mean square tracking error along a typical trajectory.A set of optimum parameters is obtained through computer simulations and the effectiveness of the proposed approach is validated by experiments on a real prototype machine.Let the traveling plate undergoes a specific trajectory and the results show that the tracking error can be reduced by at least 50%in comparison with the conventional auto-tuning and Z-N methods.The proposed approach is a whole workspace optimization and can be applied to the parameter tuning of fixed gain motion controllers.展开更多
To improve the robustness of high-precision servo systems, quantitative feedback theory （QFT） which aims to achieve a desired robust design over a specified region of plant uncertainty is proposed. The robust design...To improve the robustness of high-precision servo systems, quantitative feedback theory （QFT） which aims to achieve a desired robust design over a specified region of plant uncertainty is proposed. The robust design problem can be solved using QFT but it fails to guarantee a high precision tracking. This problem is solved by a robust digital QFT control scheme based on zero phase error （ZPE） feed forward compensation. This scheme consists of two parts： a QFT controller in the closed-loop system and a ZPE feed-forward compensator. Digital QFT controller is designed to overcome the uncertainties in the system. Digital ZPE feed forward controller is used to improve the tracking precision. Simulation and real-time examples for flight simulator servo system indicate that this control scheme can guarantee both high robust performance and high position tracking precision.展开更多
Usually, only siep future desired singals are utilized in the field of preview servo systems design. In this paper, we discuss the design problem of optimal preview servo system while the future desired signal and fut...Usually, only siep future desired singals are utilized in the field of preview servo systems design. In this paper, we discuss the design problem of optimal preview servo system while the future desired signal and future disturbance signal are polynomials or outputs of linear free systems. (1) Conditions of controllability and observability for enlarged system, (2) a design method of optimal preview servo controllers, and (3) a simple and convenient algorithm of control law are obtained.展开更多
基金the National Key Research and Development Program of China(Grant No.2017YFA0304404)the National Natural Science Foundation of China(Grant No.11674357)。
文摘A universal locking model for single ion optical clocks was built based on a simple integrator and a double integrator.Different integrator algorithm parameters have been analyzed in both numerical simulations and experiments.The frequency variation measured by the comparison of two optical clocks coincides well with the simulation results for different second integrator parameters.According to the experimental results,the sensitivity of the servo error influenced by laser frequency drift with the addition of a double integrator was suppressed by a factor of 107.In a week-long comparison of optical clocks,the relative uncertainty of the servo error is determined to be 1.9×10^(-18),which is meaningful for the systematic uncertainty of the transportable single^(40)Ca^(+)ion optical clock entering the 10^(-18)level.
文摘A technology of two-coordinate dual-servo(TCDS) is proposed. Using this technology which is based on error compensation, workpieces of higher contour accuracy could he turned on ultra-precision machine tool with Poor dynamic performances. The principle, constitute and operation of a TCDS system are described. Mathematical proof and experiments are achieved in addition.
基金This project is supported by Aeronautics Foundation of China (No.00- E51022).
文摘Flight simulator is an important device and a typical high performanceposition servo system used in the hardware-in-the-loop simulation of flight control system. Withoutusing the future desired output, zero phase error controller makes the overall system's frequencyresponse exhibit zero phase shift for all frequencies and a very small gain error at low frequencyrange can be achieved. A new algorithm to design the feed forward controller is presented, in orderto reduce the phase error, the design of proposed feed forward controller uses a modified plantmodel, which is a closed loop transfer function, through which the system tracking precisionperformance can be improved greatly. Real-time control results show the effectiveness of theproposed approach in flight simulator servo system.
基金The project was supported by Aeronautics Foundation of China (00E51022).
文摘Using the future desired input value, zero phase error controller enables the overall system＇s frequency response exhibit zero phase shift for all frequencies and a small gain error at low frequency range, and based on this, a new algorithm is presented to design the feedforward controller. However, zero phase error controller is only suitable for certain linear system. To reduce the tracking error and improve robustness, the design of the proposed feedforward controller uses a neural compensation based on diagonal recurrent neural network. Simulation and real-time control results for flight simulator servo system show the effectiveness of the proposed approach.
文摘为实现多轴伺服驱动压力机的同步控制,文章基于传统偏差耦合控制提出一种虚拟轴改进型偏差耦合同步控制方法,并搭建同步控制实验平台进行现场验证。基于压力机结构和控制模型实现模糊比例积分微分(proportional integral derivative,PID)位置跟踪控制;在传统偏差耦合控制结构中添加评价误差模块,搭建一种改进型偏差耦合同步控制方法,提高同步系统的抗扰动能力和同步精度;将虚拟轴引入改进型偏差耦合控制结构中,从而解除多轴间的直接耦合关系,简化改进型同步位移补偿结构。实验结果表明,该方法有效提高了压力机同步抗扰动能力和稳态同步精度。
基金supported by the National Basic Research Program of China (973 Program) (973-61334)
文摘In order to improve the measurement-precision of the gyro,the gyro experiment is completed based on gyro servo technology.The error sources of gyro servo technology are analyzed in the process of measurement,and the impact of these error sources on measurement is evaluated.To eliminate interference signal existing in the sampled data of the measurement,a modified wavelet threshold filtering method is presented.The results of the simulation and measurement show that the estimation-precision of the proposed method is improvement remarkably compared with the fast Fourier transform method,and the calculation work is reduced compared with the conventional wavelet threshold filtering methods,furthermore,the phenomenon of a common threshold of ＂killing＂ is solved thoroughly.
基金Supported by National Natural Science Foundation of China(Grant Nos.51305293,51135008)
文摘High-speed pick-and-place parallel robot is a system where the inertia imposed on the motor shafts is real-time changing with the system configurations.High quality of computer control with proper controller parameters is conducive to overcoming this problem and has a significant effect on reducing the robot＇s tracking error.By taking Delta robot as an example,a method for parameter tuning of the fixed gain motion controller is presented.Having identifying the parameters of the servo system in the frequency domain by the sinusoidal excitation,the PD＋feedforward control strategy is proposed to adapt to the varying inertia loads,allowing the controller parameters to be tuned by minimizing the mean square tracking error along a typical trajectory.A set of optimum parameters is obtained through computer simulations and the effectiveness of the proposed approach is validated by experiments on a real prototype machine.Let the traveling plate undergoes a specific trajectory and the results show that the tracking error can be reduced by at least 50%in comparison with the conventional auto-tuning and Z-N methods.The proposed approach is a whole workspace optimization and can be applied to the parameter tuning of fixed gain motion controllers.
基金This project was supported by the Aeronautics Foundation of China (00E51022).
文摘To improve the robustness of high-precision servo systems, quantitative feedback theory （QFT） which aims to achieve a desired robust design over a specified region of plant uncertainty is proposed. The robust design problem can be solved using QFT but it fails to guarantee a high precision tracking. This problem is solved by a robust digital QFT control scheme based on zero phase error （ZPE） feed forward compensation. This scheme consists of two parts： a QFT controller in the closed-loop system and a ZPE feed-forward compensator. Digital QFT controller is designed to overcome the uncertainties in the system. Digital ZPE feed forward controller is used to improve the tracking precision. Simulation and real-time examples for flight simulator servo system indicate that this control scheme can guarantee both high robust performance and high position tracking precision.
文摘Usually, only siep future desired singals are utilized in the field of preview servo systems design. In this paper, we discuss the design problem of optimal preview servo system while the future desired signal and future disturbance signal are polynomials or outputs of linear free systems. (1) Conditions of controllability and observability for enlarged system, (2) a design method of optimal preview servo controllers, and (3) a simple and convenient algorithm of control law are obtained.
