In hydraulic area,independent metering control(IMC)technology is an effective approach to improve system efficiency and control flexibility.In addition,digital hydraulic technology(DHT)has been verified as a reasonabl...In hydraulic area,independent metering control(IMC)technology is an effective approach to improve system efficiency and control flexibility.In addition,digital hydraulic technology(DHT)has been verified as a reasonable method to optimize system dynamic performance.Integrating these two technologies into one component can combine their advantages together.However,few works focused on it.In this paper,a twin spools valve with switching technologycontrolled pilot stage(TSVSP)is presented,which applied DHT into its pilot stage while appending IMC into its main stage.Based on this prototype valve,a series of numerical and experiment analysis of its IMC performance with both simulated load and excavator boom cylinder are carried out.Results showed fast and robust performance of pressure and flow compound control with acceptable fluctuation phenomenon caused by switching technology.Rising time of flow response in excavator cylinder can be controlled within 200 ms,meanwhile,the recovery time of rod chamber pressure under suddenly changed condition is optimized within 250 ms.IMC system based on TSVSP can improve both dynamic performance and robust characteristics of the target actuator so it is practical in valve-cylinder system and can be applied in mobile machineries.展开更多
The motivation of this work is to obtain single PI/PID tuning formula for different types of processes with enhanced disturbance rejection performance. The proposed tuning formula consistently gives better performance...The motivation of this work is to obtain single PI/PID tuning formula for different types of processes with enhanced disturbance rejection performance. The proposed tuning formula consistently gives better performance in comparison to several well-known methods at the same degree of robustness for stable, integrating and unstable processes. For the selection of the closed-loop time constant(τc), a guideline is provided over a broad range of time-delay/time-constant ratios on the basis of the peak of maximum sensitivity(Ms). An analysis has been performed for the uncertainty margin with the different process parameters for the robust controller design. It gives the guideline of the Ms-value settings for the PI controller designs based on the process parameters uncertainty. Furthermore, a relationship has been developed between Ms-value and uncertainty margin with the different process parameters(k, τ and θ). Simulation study has been conducted for the broad class of processes and the controllers are tuned to have the same degree of robustness by measuring the maximum sensitivity, Ms, in order to obtain a reasonable comparison.展开更多
In the process of capacity regulation of reciprocating compressor, the frequent change of inlet temperature and pressure makes the control of exhaust flow unstable, resulting in the high pressure ratio of the intermed...In the process of capacity regulation of reciprocating compressor, the frequent change of inlet temperature and pressure makes the control of exhaust flow unstable, resulting in the high pressure ratio of the intermediate stage. At last the compressor cannot operate safely. To solve the problem, a novel flow control scheme based on inlet temperature and pressure ratio is proposed. In this scheme, the intake model of the cylinder under the capacity regulation condition is established to calculate the load of the first cylinder. Then, the adaptive predictive PID(APPID) controller is designed to control the pressure ratio of other stages, and the grey prediction model is used to predict the pressure output to overcome the system delay. To solve the problem of control parameters tuning, an improved particle swarm optimization(PSO) algorithm is adopted to obtain the optimal control parameters.The effectiveness of the adaptive predictive PID control method is verified by a two-stage compressor model simulation.Finally, the flow control scheme is applied to the actual four-stage air reciprocating compressor flow control system. Although the temperature difference is greater than 15 ℃, the compressor exhaust flow is maintained at the set value and the pressure ratio is also maintained stable. At the same time, the compressor pressure ratio can be quickly adjusted without overshoot. The application result further verifies the feasibility and effectiveness of the scheme.展开更多
工业过程运行控制的目的是实现反映过程整体运行性能的工艺指标.将常规解耦内模控制(Internal model control,IMC)进行推广,提出了优化过程运行的解耦IMC方法.通过对广义解耦内模控制器的设计获得了具有高维解耦能力、鲁棒稳定性和抗干...工业过程运行控制的目的是实现反映过程整体运行性能的工艺指标.将常规解耦内模控制(Internal model control,IMC)进行推广,提出了优化过程运行的解耦IMC方法.通过对广义解耦内模控制器的设计获得了具有高维解耦能力、鲁棒稳定性和抗干扰能力强的回路设定模型.该模型能够响应系统的各种不确定性和干扰,对回路设定值进行调整,通过控制回路的输出跟踪凋整后的设定值,从而实现期望的工艺指标.磨矿回路运行的解耦IMC设计实例及仿真验证了所提方法的有效性.展开更多
内模控制(internal model control,IMC)因其结构简单、易于实现已得到广泛关注,但其控制性能与滤波器时间常数有直接关系,影响了其在高性能变频调速系统中的应用。该文提出了一种采用免疫算法的感应电机内模控制策略,以免疫应答系统为基...内模控制(internal model control,IMC)因其结构简单、易于实现已得到广泛关注,但其控制性能与滤波器时间常数有直接关系,影响了其在高性能变频调速系统中的应用。该文提出了一种采用免疫算法的感应电机内模控制策略,以免疫应答系统为基础,引入一种免疫算法,分析了该算法的实现方式。将该免疫算法植入到内模控制器中,实现对滤波时间常数的在线调整,克服了内模控制器因滤波时间常数固定带来的系统动态性能不佳的问题。仿真与实验结果验证了采用免疫算法的感应电机内模控制策略的有效性。展开更多
介绍了内模控制的发展历史及基本原理,分析了其控制器的设计方法,提出了一种利用Taylor级数展开的基于内模控制(Internal Model control,IMC)的PID控制器参数整定的方法.通过对热交换器PID温度调节闭环控制系统的MATLAB实例仿真,将IMC-...介绍了内模控制的发展历史及基本原理,分析了其控制器的设计方法,提出了一种利用Taylor级数展开的基于内模控制(Internal Model control,IMC)的PID控制器参数整定的方法.通过对热交换器PID温度调节闭环控制系统的MATLAB实例仿真,将IMC-PID整定的效果与传统PID进行对比,论证其控制效果明显优于其它经典PID整定,显示了其实际工程应用价值.展开更多
基金Supported by National Natural Science Foundation of China(Grant Nos.52005441,51890885)open Foundation of the State Key Laboratory of Fluid Power and Mechatronic Systems(Grant No.GZKF-201906)+1 种基金Zhejiang Province Natural Science Foundation of China(Grant No.LQ21E050017)China Postdoctoral Science Foundation(Grant Nos.2021M692777,2021T140594).
文摘In hydraulic area,independent metering control(IMC)technology is an effective approach to improve system efficiency and control flexibility.In addition,digital hydraulic technology(DHT)has been verified as a reasonable method to optimize system dynamic performance.Integrating these two technologies into one component can combine their advantages together.However,few works focused on it.In this paper,a twin spools valve with switching technologycontrolled pilot stage(TSVSP)is presented,which applied DHT into its pilot stage while appending IMC into its main stage.Based on this prototype valve,a series of numerical and experiment analysis of its IMC performance with both simulated load and excavator boom cylinder are carried out.Results showed fast and robust performance of pressure and flow compound control with acceptable fluctuation phenomenon caused by switching technology.Rising time of flow response in excavator cylinder can be controlled within 200 ms,meanwhile,the recovery time of rod chamber pressure under suddenly changed condition is optimized within 250 ms.IMC system based on TSVSP can improve both dynamic performance and robust characteristics of the target actuator so it is practical in valve-cylinder system and can be applied in mobile machineries.
基金the support provided by King Abdulaziz City for Science and Technology (KACST) through the "KACST Annual Program" at King Fahd University of Petroleum & Minerals (KFUPM) for funding this work through project number AT-32-41
文摘The motivation of this work is to obtain single PI/PID tuning formula for different types of processes with enhanced disturbance rejection performance. The proposed tuning formula consistently gives better performance in comparison to several well-known methods at the same degree of robustness for stable, integrating and unstable processes. For the selection of the closed-loop time constant(τc), a guideline is provided over a broad range of time-delay/time-constant ratios on the basis of the peak of maximum sensitivity(Ms). An analysis has been performed for the uncertainty margin with the different process parameters for the robust controller design. It gives the guideline of the Ms-value settings for the PI controller designs based on the process parameters uncertainty. Furthermore, a relationship has been developed between Ms-value and uncertainty margin with the different process parameters(k, τ and θ). Simulation study has been conducted for the broad class of processes and the controllers are tuned to have the same degree of robustness by measuring the maximum sensitivity, Ms, in order to obtain a reasonable comparison.
基金Supported by the State Key Laboratory of Compressor Technology Open Fund Project(No.SKLYSJ201808/SKLYS201811)the National Key Research and Development Plan(No.2016YFF0203305).
文摘In the process of capacity regulation of reciprocating compressor, the frequent change of inlet temperature and pressure makes the control of exhaust flow unstable, resulting in the high pressure ratio of the intermediate stage. At last the compressor cannot operate safely. To solve the problem, a novel flow control scheme based on inlet temperature and pressure ratio is proposed. In this scheme, the intake model of the cylinder under the capacity regulation condition is established to calculate the load of the first cylinder. Then, the adaptive predictive PID(APPID) controller is designed to control the pressure ratio of other stages, and the grey prediction model is used to predict the pressure output to overcome the system delay. To solve the problem of control parameters tuning, an improved particle swarm optimization(PSO) algorithm is adopted to obtain the optimal control parameters.The effectiveness of the adaptive predictive PID control method is verified by a two-stage compressor model simulation.Finally, the flow control scheme is applied to the actual four-stage air reciprocating compressor flow control system. Although the temperature difference is greater than 15 ℃, the compressor exhaust flow is maintained at the set value and the pressure ratio is also maintained stable. At the same time, the compressor pressure ratio can be quickly adjusted without overshoot. The application result further verifies the feasibility and effectiveness of the scheme.
文摘工业过程运行控制的目的是实现反映过程整体运行性能的工艺指标.将常规解耦内模控制(Internal model control,IMC)进行推广,提出了优化过程运行的解耦IMC方法.通过对广义解耦内模控制器的设计获得了具有高维解耦能力、鲁棒稳定性和抗干扰能力强的回路设定模型.该模型能够响应系统的各种不确定性和干扰,对回路设定值进行调整,通过控制回路的输出跟踪凋整后的设定值,从而实现期望的工艺指标.磨矿回路运行的解耦IMC设计实例及仿真验证了所提方法的有效性.
文摘内模控制(internal model control,IMC)因其结构简单、易于实现已得到广泛关注,但其控制性能与滤波器时间常数有直接关系,影响了其在高性能变频调速系统中的应用。该文提出了一种采用免疫算法的感应电机内模控制策略,以免疫应答系统为基础,引入一种免疫算法,分析了该算法的实现方式。将该免疫算法植入到内模控制器中,实现对滤波时间常数的在线调整,克服了内模控制器因滤波时间常数固定带来的系统动态性能不佳的问题。仿真与实验结果验证了采用免疫算法的感应电机内模控制策略的有效性。
文摘介绍了内模控制的发展历史及基本原理,分析了其控制器的设计方法,提出了一种利用Taylor级数展开的基于内模控制(Internal Model control,IMC)的PID控制器参数整定的方法.通过对热交换器PID温度调节闭环控制系统的MATLAB实例仿真,将IMC-PID整定的效果与传统PID进行对比,论证其控制效果明显优于其它经典PID整定,显示了其实际工程应用价值.
