Hsin-Teng Sheu

H filtering and solution bound for non-linear systems

In this paper, sufficient conditions for the existence of a solution to the non-linear H filtering problem are presented. The conditions are expressed in terms of the solution to a Hamilton-Jacobi inequality involving only n + 1 (for time-varying case) or n (for time-invariant case) independent variables. Both affine and general non-linear systems are examined. In the time-invariant affine non-linear case, one kind of positive radial solution to the Hamilton-Jacobi inequality is presented, and an explicit estimation of the achievable disturbance attenuation level is given. Illustrative examples are also included.

Representation of 3D surfaces by two-variable Fourier descriptors

A method for generating two-variable 3D FDs directly from a striped lighting system is developed. An iterative algorithm is proposed to compute the two-variable 3D FDs for both axisymmetric and nonaxisymmetric objects and a formula for convergence test is derived. Experiments conducted for a set of 3D objects show that the iterative algorithm converges very quickly and the two-variable 3D FD representations are attained accurately.

H/sup /spl infin// filtering and solution bound for nonlinear systems

In this paper, sufficient conditions are presented for the existence of a solution to the nonlinear H/sup /spl infin// filtering problem. The conditions are expressed in terms of the solution to a Hamilton-Jacobi inequality involving only n+1 (for time-varying case) or n (for time-invariant case) independent variables. Both affine and general nonlinear systems are examined. In the time-invariant affine nonlinear case, we also present one kind of positive radial solution to the Hamilton-Jacobi inequality, and give an explicit estimation of the achievable disturbance attenuation level.

H∞ filtering of nonlinear systems with sampled measurements

Abstract In this paper, the H ∞ filtering problem is studied for nonlinear continuous-time systems with sampled measurements. Sufficient conditions are derived for the existence of filters that satisfy a specified H ∞ performance bound. These conditions are expressed in terms of the solution of a differential Hamilton–Jacobi inequality with jumps. When these conditions hold, state-space formulae are also given for such a filter. A numerical example is included to illustrate the proposed filter design method.

An intelligent automated door control system based on a smart camera.

This paper presents an innovative access control system, based on human detection and path analysis, to reduce false automatic door system actions while increasing the added values for security applications. The proposed system can first identify a person from the scene, and track his trajectory to predict his intention for accessing the entrance, and finally activate the door accordingly. The experimental results show that the proposed system has the advantages of high precision, safety, reliability, and can be responsive to demands, while preserving the benefits of being low cost and high added value.

A Statistical Method for Generic Foreground Detection

Traditional approaches such as Gaussian mixture model (GMM), Otsus and moment preserving (MP) methods are developed for segmentation of opaque objects. For semi-opaque objects like flame and smoke the result is cluttered, due to inappropriate threshold, especially if one dominates the other. Besides, rapidly changing environments like foggy and rainy scenes increase the difficulty in foreground detection. We propose a statistical method for the detection of both ＂opaque objects＂ and ＂semi-opaque objects＂ that works in all weather conditions. We use difference of histogram and ANOVA for candidate foreground detection and Students t-test for object segmentation. Experiments are conducted for both ＂opaque＂ and ＂semi-opaque objects＂ under both clear and severe weather conditions. The results show that for ＂opaque objects＂, the recall of the proposed is 0.941, while for ＂semi-opaque objects＂, the recall is 0.895. In the scenes where both types of objects exist, the recall remain at 0.901. In severe weather conditions, the recalls are 0.93 and 0.88 for ＂opaque＂ and ＂semi-opaque objects＂, respectively.

On reduced-order H/sup /spl infin// filtering for nonlinear systems

In this paper, sufficient conditions are presented for the existence of an H/sup /spl infin// filter with a state dimension less than the plant. The conditions are expressed in terms of the solution to a Hamilton-Jacobi inequality which is exactly the one used in the construction of the full-order H/sup /spl infin// filters. Both affine and general non-affine nonlinear systems are examined. The development uses only elementary concepts of dissipativity and differential games; thus, the proofs given are simple and clear.