Zhanlin Wang

Pressure loop control of pump and valve combined EHA based on FFIM

Based on the specificity of pump and valve combined EHA that valve control loop response higher than pressure loop and the characters of time-varying, nonlinearity of pressure loop, the feed-forward fuzzy immune (FFIM)control algorithm was proposed to adjust PID control parameters real time and increase response and control capability of pressure loop, through add error signal to position loop as feed-forward signal, and using immune algorithm adjusting pressure loop control parameters real time which has optimizing performance and using fuzzy algorithm as operator function. The simulation result shown the response of pressure loop was increased by add feed-forward signal, but the pressure value rising, and immune algorithm reduces the pressure fluctuation around the pressure setting value. The joint of feed-forward and immune not only increase the response but also decrease pressure fluctuation and increase the control capacity to complex characters of pressure loop.

Accelerated life testing design based on wear failure mechanism for pneumatic cylinders

The piston and piston pole sealing ring are the weak units as well as leakage sources which easily result in the cylinders failure. The primary criterion for determining test acceleration factors is that the failure mode or failure mechanism should not change or be different from that expected from a non-accelerated test. Working temperature, frequency and motion velocity are chosen as stresses for the specific cylinders. Three kinds of testing stress spectrum are designed. The data evaluation results show that there is no change for the cylinders as to the failure mechanism. All the data acquired are efficiently and valuably used to estimate the reliability of the products.

Development of Brake-By-Wire Hardware-In-Loop Simulation Bench

This paper mainly describes a PC-based Brake-By-Wire Hardware-In-Loop-simulation Bench which has high efficiency and applicability. System architecture, hardware configuration, and software model of this bench are presented in details. The electric braking controllers collect, process and transfer all kinds of information, and generate simultaneous control codes according to the control algorithm, then drive electromechanical actuator and braking parts. For improving the safety and reliability, redundancy is adopted to realize reconstruction when the simulation system occurs faults. Experiments show this simulation bench is a practical tool for the design, test and parameter optimization for electric braking system.

Aircraft multiplex mechatronic system control strategy based on task management

The abilities of synthesized function, intelligent control and health monitor for airborne utilities are becoming more and more important by which all the systems work efficiently and coordinately can be ensured. avionics and other systems work in order. This paper works over several items about UMS by introducing updated simulation framework and redundancy and fault tolerance. In order to obtain high performance of distributed process ability, heuristic job dispatching algorithm and hydrodynamic load balancing strategy are used to solve the static job dispatch and dynamic job scheduling respectively. Dynamic fault tolerance load balancing with and without failure occurs are simulated. Experiment result shows that communication cost is minimized, multiplex task redundancy and system real time performance are finally satisfied.

Frequency coverter PDFSV control based on inertia identification

Excitation current and torque current are decoupled through vector control in frequency converter, so the linear control method can be used in speed loop. Pseudo derivative feedback with sub-variable control (PDFSV) has excellent performance and easy to realize. Its control parameters are obtained through present equation which is related to inertia parameter. To the frequency converter system with parameter changes at extensive range, the PDFSV control with variable control coefficient is presented: to construct full-order state observer, to observe the speed error signal which contains error information on the moment of inertia and calculate control coefficient by presented equations, and feed forward the observed load. The simulation results show that the speed control response performance well when the moment of inertia and disturb load varied at extensive range.

Focusing on accelerated life testing for cylinders

The study of accelerated life test on cylinders for pneumatic industry is covered in this paper. Accelerated life testing is valuable tools to get information quickly on life distribution which is achieved by subjecting the test units to conditions that are more severe than the normal ones. Long lifetime pneumatic cylinders are selected as the test object. Section I covers the fault mechanism analysis, the piston and piston pole parking are the weak units as they are movable parts as well as leakage sources which easily result in the cylinders failure. Liquid temperature and operating frequency are chosen as stresses since their accelerating potentials are available for the specific cylinders. The complete ALT data is presented using Weibull distribution. Estimation for the parameters of failure model and other characteristics of cylinders population life distribution are done successfully. From the 3-axis graph plotted, the effects of each stresses to cylinders can be seen clearly which provide useful results for cylinders researcher and developer.

Issues on utility management simulation system for miscellaneous airborne electromechanical devices

UMS for miscellaneous airborne electromechanical devices is the part and parcel of VMS. The object of utility management is airborne electromechanical devices which ensure that air engine, avionics and other systems work in order. This paper works over several items about UMS by introducing advanced simulation and its correlative technologies. Firstly, message transmission software of 1553B bus is designed and the bus characteristics are tested. Also, the problem of time synchronization is solved by testing network delay. Secondly, in order to obtain high performance of distributed process ability, heuristic job dispatching algorithm and hydrodynamic load balancing strategy are adopted, which solve the static job dispatch and dynamic job scheduling respectively. The hydrodynamic load balancing strategy is aiming to fulfill the resources usage in the whole system and accomplishes best resources sharing. Thirdly, this paper establishes and realizes the demo environment for visual simulation of the electromechanical subsystems. Adopting tree-mode during the software design makes the system scalable and reconstruction. As multithreading synchronization is resolved, real-time performance of simulation. is ensured during.

Key technologies of a utility management simulation system

The simulation platform of utility management system is a distributed computer network hierarchy which is demanded to complete certain real-time tasks during scheduled time. In addition, to make the airplane with high reliability, the real-time tasks need to be completed smoothly when the system is in the fault situation. Taking the real-time character and fault-tolerance of the system into account, this paper proposes the topological architecture of the simulation platform and its simplified model, and concludes the cost function term which makes the redundant system with minimum cost on the condition of load balance.