在实时性导通控制中,常用过零检测法和锁相环法。比较了过零检测法、三相单同步、三相双同步坐标系锁相环法,提出了适用于混合式固态交流断路器(Hybird Solid State Switch,HSSS)的单相自解耦锁相策略,并给出了数学模型和控制模型,通过...在实时性导通控制中,常用过零检测法和锁相环法。比较了过零检测法、三相单同步、三相双同步坐标系锁相环法,提出了适用于混合式固态交流断路器(Hybird Solid State Switch,HSSS)的单相自解耦锁相策略,并给出了数学模型和控制模型,通过分析稳态性能和动态性能得出了控制参数。在MATLAB/Simulink环境下构建上述实时性控制模型与HSSS模型,通过仿真与最优化分析验证了单相自解耦锁相环在各种电网电压工况下具有良好的锁相效果,能够实现HSSS的基本功能,满足实时性控制要求。展开更多
A three-DOF (degree of freedom) planar robot completely restrained and positioned parallel pulled by four wires was studied. The wire driving properties were analyzed through experiments. The restrained three-DOF plan...A three-DOF (degree of freedom) planar robot completely restrained and positioned parallel pulled by four wires was studied. The wire driving properties were analyzed through experiments. The restrained three-DOF planar platform was established based on slippery course and bearing, and dSPACE real-time control system was used to perform the platform's motion control experiment on robot. Based on the kinematic equation and mechanical balance equation of moving platform, the stiffness of the robot system was analyzed and the calibration scheme of the system considering wire tension was put forward. Position servo control experiments were carried out, position servo tracking precision was analyzed, and real-time wire tension was detected. The results show that the moving error of the moving platform tracking is small (the maximum difference is about 3%), and the rotation error is large (the maximum difference is about 12%). The wire tension has wave properties (the wire tension fluctuation is about 10 N).展开更多
In order to reduce the load rate of CAN bus and improve the real-time performance of control system, CAN bus control system of a pure electric vehicle is studied. Communication messages of each node are optimized and ...In order to reduce the load rate of CAN bus and improve the real-time performance of control system, CAN bus control system of a pure electric vehicle is studied. Communication messages of each node are optimized and redefined by sorting the message into three types： control message, status message and alann message. Event triggered mode is added to the communication way of CAN bus, and the communication control strategy of the vehicle is made. It is proved that CAN bus load rate of control system is reduced after optimization, and the real-time performance of communication is improved effectively.展开更多
Based on the abort strategy of fixed periods, a novel predictive control scheduling methodology was proposed to efficiently solve overrun problems. By applying the latest control value in the prediction sequences to t...Based on the abort strategy of fixed periods, a novel predictive control scheduling methodology was proposed to efficiently solve overrun problems. By applying the latest control value in the prediction sequences to the control objective, the new strategy was expected to optimize the control system for better performance and yet guarantee the schedulability of all tasks under overrun. The schedulability of the real-time systems with p-period overruns was analyzed, and the corresponding stability criteria was given as well. The simulation results show that the new approach can improve the performance of control system compared to that of conventional abort strategy, it can reduce the overshoot and adjust time as well as ensure the schedulability and stability.展开更多
Actors'relocation is utilized during the network initialization to enhance real-time performance of wireless sensor and actor networks(WSANs)which is an important issue of WSANs.The actor deployment problem in WSA...Actors'relocation is utilized during the network initialization to enhance real-time performance of wireless sensor and actor networks(WSANs)which is an important issue of WSANs.The actor deployment problem in WSANs is proved NP-Hard whether the amount of actors is redundant or not,but to the best of our knowledge,no effective distributed algorithms in previous research can solve the problem.Thus two actor deployment strategies which need not the boundary control compared with present deployment strategies are proposed to solve this problem approximately based on the Voronoi diagram.Through simulation experiment,the results show that our distributed strategies are more effective than the present deployment strategies in terms of real-time performance,convergence time and energy consumption.展开更多
During the operation of complex process, such as oil production or refming, abnormal situations may occur, leading to an alarm flooding. Alarm flooding is the signalling of a large number of alarms in a few minutes, i...During the operation of complex process, such as oil production or refming, abnormal situations may occur, leading to an alarm flooding. Alarm flooding is the signalling of a large number of alarms in a few minutes, in such a way that it is impossible for the operator to attend to all alarms. On these occasions, it is usual that the operator leaves the alarm summary list and gets an analysis of the plant through the screens of the DCS （digital control system）, seeking to understand the situation. The alarm summary list ceases to be a useful tool. In such cases, the operator might have the aid of a filter that would present the highest priority alarms and other information associated with them, enabling him to gain a better knowledge of the situation. This paper describes the interface of a system aimed to help the operator to have a more comprehensive knowledge of the process （a better situational awareness） during process upsets that cause alarm flooding, recovering the utility of the alarm layer to the safety of industrial processes.展开更多
By taking advantage of the separation characteristics of nonlinear gain and dynamic sector inside a Hammerstein model, a novel pole placement self tuning control scheme for nonlinear Hammerstein system was put forward...By taking advantage of the separation characteristics of nonlinear gain and dynamic sector inside a Hammerstein model, a novel pole placement self tuning control scheme for nonlinear Hammerstein system was put forward based on the linear system pole placement self tuning control algorithm. And the nonlinear Hammerstein system pole placement self tuning control(NL-PP-STC) algorithm was presented in detail. The identi fication ability of its parameter estimation algorithm of NL-PP-STC was analyzed, which was always identi fiable in closed loop. Two particular problems including the selection of poles and the on-line estimation of model parameters, which may be met in applications of NL-PP-STC to real process control, were discussed. The control simulation of a strong nonlinear p H neutralization process was carried out and good control performance was achieved.展开更多
文摘在实时性导通控制中,常用过零检测法和锁相环法。比较了过零检测法、三相单同步、三相双同步坐标系锁相环法,提出了适用于混合式固态交流断路器(Hybird Solid State Switch,HSSS)的单相自解耦锁相策略,并给出了数学模型和控制模型,通过分析稳态性能和动态性能得出了控制参数。在MATLAB/Simulink环境下构建上述实时性控制模型与HSSS模型,通过仿真与最优化分析验证了单相自解耦锁相环在各种电网电压工况下具有良好的锁相效果,能够实现HSSS的基本功能,满足实时性控制要求。
基金Project(20102304120007) supported by the Research Fund for the Doctoral Program of Higher Education of ChinaProject(QC2010009)supported by the Natural Science Foundation of Heilongjiang Province, China+1 种基金Projects(20110491030, LBH-Z10219) supported by China Postdoctoral Science FoundationProject(HEUCF120706) supported by the Fundamental Research Funds for the Central Universities of China
文摘A three-DOF (degree of freedom) planar robot completely restrained and positioned parallel pulled by four wires was studied. The wire driving properties were analyzed through experiments. The restrained three-DOF planar platform was established based on slippery course and bearing, and dSPACE real-time control system was used to perform the platform's motion control experiment on robot. Based on the kinematic equation and mechanical balance equation of moving platform, the stiffness of the robot system was analyzed and the calibration scheme of the system considering wire tension was put forward. Position servo control experiments were carried out, position servo tracking precision was analyzed, and real-time wire tension was detected. The results show that the moving error of the moving platform tracking is small (the maximum difference is about 3%), and the rotation error is large (the maximum difference is about 12%). The wire tension has wave properties (the wire tension fluctuation is about 10 N).
文摘In order to reduce the load rate of CAN bus and improve the real-time performance of control system, CAN bus control system of a pure electric vehicle is studied. Communication messages of each node are optimized and redefined by sorting the message into three types： control message, status message and alann message. Event triggered mode is added to the communication way of CAN bus, and the communication control strategy of the vehicle is made. It is proved that CAN bus load rate of control system is reduced after optimization, and the real-time performance of communication is improved effectively.
基金Project (60505018) supported by the National Natural Science Foundation of China
文摘Based on the abort strategy of fixed periods, a novel predictive control scheduling methodology was proposed to efficiently solve overrun problems. By applying the latest control value in the prediction sequences to the control objective, the new strategy was expected to optimize the control system for better performance and yet guarantee the schedulability of all tasks under overrun. The schedulability of the real-time systems with p-period overruns was analyzed, and the corresponding stability criteria was given as well. The simulation results show that the new approach can improve the performance of control system compared to that of conventional abort strategy, it can reduce the overshoot and adjust time as well as ensure the schedulability and stability.
基金Supported by the National Natural Science Foundation of China(No.60803148,60973124)
文摘Actors'relocation is utilized during the network initialization to enhance real-time performance of wireless sensor and actor networks(WSANs)which is an important issue of WSANs.The actor deployment problem in WSANs is proved NP-Hard whether the amount of actors is redundant or not,but to the best of our knowledge,no effective distributed algorithms in previous research can solve the problem.Thus two actor deployment strategies which need not the boundary control compared with present deployment strategies are proposed to solve this problem approximately based on the Voronoi diagram.Through simulation experiment,the results show that our distributed strategies are more effective than the present deployment strategies in terms of real-time performance,convergence time and energy consumption.
文摘During the operation of complex process, such as oil production or refming, abnormal situations may occur, leading to an alarm flooding. Alarm flooding is the signalling of a large number of alarms in a few minutes, in such a way that it is impossible for the operator to attend to all alarms. On these occasions, it is usual that the operator leaves the alarm summary list and gets an analysis of the plant through the screens of the DCS （digital control system）, seeking to understand the situation. The alarm summary list ceases to be a useful tool. In such cases, the operator might have the aid of a filter that would present the highest priority alarms and other information associated with them, enabling him to gain a better knowledge of the situation. This paper describes the interface of a system aimed to help the operator to have a more comprehensive knowledge of the process （a better situational awareness） during process upsets that cause alarm flooding, recovering the utility of the alarm layer to the safety of industrial processes.
文摘By taking advantage of the separation characteristics of nonlinear gain and dynamic sector inside a Hammerstein model, a novel pole placement self tuning control scheme for nonlinear Hammerstein system was put forward based on the linear system pole placement self tuning control algorithm. And the nonlinear Hammerstein system pole placement self tuning control(NL-PP-STC) algorithm was presented in detail. The identi fication ability of its parameter estimation algorithm of NL-PP-STC was analyzed, which was always identi fiable in closed loop. Two particular problems including the selection of poles and the on-line estimation of model parameters, which may be met in applications of NL-PP-STC to real process control, were discussed. The control simulation of a strong nonlinear p H neutralization process was carried out and good control performance was achieved.
