Zhu Chang-an

Modeling the dynamics of biomimetic underwater robot fish

In this paper we propose the model for undulatory locomotion in the developed biomimetic underwater robot fish. The expressions for the momentum and hydrodynamic force on the swimming robot fishs body are based on large-amplitude elongated body theory and inviscid hydrodynamics, and these are coupled to rigid-body dynamics to derive the kinematic and dynamic equation of the swimming robot fish. Through solving ordinary differential equation, propulsive parameters including swimming velocity, thrust, side force and efficiency can be obtained. For improving the swimming performances, influences of kinetic parameters of body curve and wake structure on these indexes are discussed and we also present the optimal body curves parameters and the Strouhal number

Obstacle detection using adaptive color segmentation and planar projection stereopsis for mobile robots

Obstacle detection is a key component of autonomous systems. In this paper, we describe an obstacle detection methodology which combines two complimentary methods: adaptive color segmentation and planar projection stereopsis, This algorithm is particularly suited for environments in which the terrain is relatively flat and of roughly the same color. We show results in applying this method to detect some indoor obstacles.

Inference Method for Fault Diagnosis of Complex Systems Based on Bayesian Network

Bayesian network (BN) is applied to the field of fault diagnosis to improve the inference ability of fault diagnosis. Therefore, fault Bayesian network (FBN) for the complex systems is proposed, and the inference method using FBN to make fault diagnosis is given in the paper. In the given method, inference of fault diagnosis includes the following processes: mapping complex systems into fault Bayesian network, transforming inference structures, initializing beliefs, propagating and absorbing beliefs and computing probability distributions. Besides, corresponding computing methods are given. At last, the proposed method is exemplified by a fault diagnosis of a digital circuit system.

Design, analysis and control of a precision feeding system of diffraction grating ruling engine

The transport of grating blank at the nanometer scale is the key of diffraction grating fabrication technology. In this paper, a precision grating blank feeding system for a diffraction grating ruling engine was described in detail, and the dynamic characterization of fine motion stage (FMS) in the dual-actuated stage, in which a piezoelectric actuator (PA) are used as the driving elements, has been investigated to provide more accurate predictions of positioning performance via simulation and experiments. A PID control system with Background Propagation (BP) neural network is employed as control strategy to see whether the system can provides precision positioning for grating blank in closed loop. All the work is validated by experimental tests based on laser interference measurement system. The main objective is to identify a procedure giving the dynamic characterization for the precision feeding system of the diffraction grating ruling engine, in order to establish a better condition in the ruling process of the grating fabrication.

Solar-Powered Drip Irrigation System

The continuous increase in population and its demand for water and energy have caused great stress on the world’s water and energy resources. Consequently, it has become necessary to replace the conventional sources of energy with renewable energy and conventional methods of irrigation with high-efficiency irrigation systems to ensure global energy, food, and environmental security. In this context, a research-based study combining drip irrigation and photovoltaic system was conducted. A solar-powered drip irrigation system was designed, developed, and analyzed techno-economically for citrus, olive, and grapes. The performance evaluation has shown enormous results with water saving and fertilizer reduction of more than 50% and 40%, respectively, as compared to conventional irrigation system. Further, the system is found cost-effective over the years and requires minimal operational and maintenance cost. This paper may provide technical guidance for design and installation of solar-powered drip irrigation system.

An integrated design and optimization platform for vibration isolation system of vehicles

An integrated design and optimization platform for vehicles vibration isolation system is presented. The integrated platform can not only direct the design by getting the precise analyze result of 3D models, but also carry through multi-objective optimization based on genetic algorithms. These can both expedite the optimization and improve the optimization result. Furthermore, we validate the reliability and validity of the platform by optimizing a heavy forklift.