Papers by Author: Jian Xin Liu

Abstract: This paper presents a kind of all-digital integrated hydraulic actuator (IHA) unit to drive heavy load object without centralized oil tank. In order to improve the control quality of the actuation system while eliminating or reducing the disturbance, and also to solve the problem of flow rate mismatch existed in IHA with single-rod cylinder actuator, a fuzzy PID PWM controller is suggested. Simulations on the integrated hydraulic actuator unit are carried out to evaluate the effectiveness of the proposed control method when applied to hydraulic systems with various external disturbances encountered in real working conditions. Simulation results are discussed and some conclusions are given.

Abstract: Welding process of automobile panels is a key process in the manufacturing of automobile body and its quality directly impact on the appearance and quality of automobile. The causes of dimensional deviation of welded assembly could be workpieces variation, assembly tooling variation, and welding distortion. As a major source of assembly deviation, dimensional variations of workpieces have important effects on the assembly quality of automobile body. In this paper, pre-stressing was used to reflect the workpieces’ variation and the node coupling method was used in the numerical simulation to predict the deformation of assembly caused by the welding process of automobile panels. And further the computation results were listed and compared with the measured ones.