Wang Shoukun

Robust fault detection using iterative learning observer for nonlinear systems

A robust fault detection scheme for a class of nonlinear systems with modeling uncertainty and inaccessible states was presented. Only the inputs and outputs of the system can be measured. A nonlinear iterative learning observer was utilized to produce the residual that was robust to uncertainty. The stability of the fault detection scheme under certain assumptions was analyzed. An example demonstrates the efficiency of the proposed fault detection strategy.

Quantitative Performance Modeling and Evaluation for Servo Control Systems Based on F-AHP

It is difficult to acquire quantitative performance evaluation result of servo control system with high precision and complex indexes, so the fuzzy analytic hierarchy process (F-AHP) is applied to quantitatively evaluate the performance of servo control system. Firstly the evaluation model with multi layers and indexes are founded, then the evaluation principle based on F-AHP is researched which is made up of model, determination for weights, calculation of membership and comprehensive evaluation. Analysis and experiments with actual data of electro-hydraulic servo test system has showed that the quantitative performance scores of servo control system can be obtained successfully by means of F-AHP, and the evaluation principle based on F-AHP is applicable not only to servo control system but also to other complex systems

Terrain estimation and strategy for quadruped robot body posture and COG adjustment

Quadruped robot has gained its popularity due to the adaptation ability of rough terrain. To improve the walking stability and balance of quadrupeds, separate static walking methods are discussed based on specific known terrains. For some unknown terrains, a uniform terrain model is established in this paper. A fuzzy logic based terrain estimation method is then proposed to estimate the terrain parameters. Based on the criterion of maximum working space, a body posture and center of gravity (COG) position adjusting strategy is proposed, and a method to adjust the posture and COG position is derived based on the kinematic analysis. Simulations show that the proposed methods can deal with different terrains and body posture and COG position can be tuned according to the terrain.