Hydraulic piston pumps are commonly used in aircraft. In order to improve the viability of aircraft and energy efficiency, intelligent variable pressure pump systems have been used in aircraft hydraulic systems more a...Hydraulic piston pumps are commonly used in aircraft. In order to improve the viability of aircraft and energy efficiency, intelligent variable pressure pump systems have been used in aircraft hydraulic systems more and more widely. Efficient fault diagnosis plays an important role in improving the reliability and performance of hydraulic systems. In this paper, a fault diagnosis method of an intelligent hydraulic pump system（IHPS） based on a nonlinear unknown input observer（NUIO） is proposed. Different from factors of a full-order Luenberger-type unknown input observer, nonlinear factors of the IHPS are considered in the NUIO. Firstly, a new type of intelligent pump is presented, the mathematical model of which is established to describe the IHPS. Taking into account the real-time requirements of the IHPS and the special structure of the pump, the mechanism of the intelligent pump and failure modes are analyzed and two typical failure modes are obtained. Furthermore, a NUIO of the IHPS is performed based on the output pressure and swashplate angle signals. With the residual error signals produced by the NUIO, online intelligent pump failure occurring in real-time can be detected. Lastly, through analysis and simulation, it is confirmed that this diagnostic method could accurately diagnose and isolate those typical failure modes of the nonlinear IHPS. The method proposed in this paper is of great significance in improving the reliability of the IHPS.展开更多
选择一组能够检测并隔离所有故障的故障检测隔离集(FDIS)是动态系统基于模型故障检测与隔离(FDI)的重要步骤,该步骤通常要求FDIS的基数最小,即求解最小故障检测隔离集(MFDIS),MFDIS的求解时间随着问题规模增大呈指数级增长。BILP(Binary...选择一组能够检测并隔离所有故障的故障检测隔离集(FDIS)是动态系统基于模型故障检测与隔离(FDI)的重要步骤,该步骤通常要求FDIS的基数最小,即求解最小故障检测隔离集(MFDIS),MFDIS的求解时间随着问题规模增大呈指数级增长。BILP(Binary integer linear programming)完备方法是现行动态系统中通用和最高效的MFDIS求解方法,但该方法的求解效率有待提高。本文首次提出了基于部分最大可满足性问题(PMS)的MFDIS求解方法。提出极小超定方程集(MSO)的概念,将部分MSO集合用MSO等价集表示,以缩减问题规模。将MFDIS求解问题转化为PMS问题,进而提高求解效率。实验结果表明,本文方法将问题规模平均约简至原来的8.22%;与BILP方法相比,本文方法的求解效率提高了4.18~9.5倍。展开更多
基金co-supported by the National Natural Science Foundation of China (Nos. 51620105010, 51575019 and 51675019)National Basic Research Program of China (No. 2014CB046400)111 Program of China
文摘Hydraulic piston pumps are commonly used in aircraft. In order to improve the viability of aircraft and energy efficiency, intelligent variable pressure pump systems have been used in aircraft hydraulic systems more and more widely. Efficient fault diagnosis plays an important role in improving the reliability and performance of hydraulic systems. In this paper, a fault diagnosis method of an intelligent hydraulic pump system（IHPS） based on a nonlinear unknown input observer（NUIO） is proposed. Different from factors of a full-order Luenberger-type unknown input observer, nonlinear factors of the IHPS are considered in the NUIO. Firstly, a new type of intelligent pump is presented, the mathematical model of which is established to describe the IHPS. Taking into account the real-time requirements of the IHPS and the special structure of the pump, the mechanism of the intelligent pump and failure modes are analyzed and two typical failure modes are obtained. Furthermore, a NUIO of the IHPS is performed based on the output pressure and swashplate angle signals. With the residual error signals produced by the NUIO, online intelligent pump failure occurring in real-time can be detected. Lastly, through analysis and simulation, it is confirmed that this diagnostic method could accurately diagnose and isolate those typical failure modes of the nonlinear IHPS. The method proposed in this paper is of great significance in improving the reliability of the IHPS.
文摘选择一组能够检测并隔离所有故障的故障检测隔离集(FDIS)是动态系统基于模型故障检测与隔离(FDI)的重要步骤,该步骤通常要求FDIS的基数最小,即求解最小故障检测隔离集(MFDIS),MFDIS的求解时间随着问题规模增大呈指数级增长。BILP(Binary integer linear programming)完备方法是现行动态系统中通用和最高效的MFDIS求解方法,但该方法的求解效率有待提高。本文首次提出了基于部分最大可满足性问题(PMS)的MFDIS求解方法。提出极小超定方程集(MSO)的概念,将部分MSO集合用MSO等价集表示,以缩减问题规模。将MFDIS求解问题转化为PMS问题,进而提高求解效率。实验结果表明,本文方法将问题规模平均约简至原来的8.22%;与BILP方法相比,本文方法的求解效率提高了4.18~9.5倍。
