Zhang Xiao-hua

Localization technique research of a pipeline robot based on the magnetic-dipole model

The magnetic field distribution of an emission antenna is studied in this paper. When the slenderness ratio of the emission antenna is high, the emission antenna can be simplified as a magnetic dipole for practical application. The numerical results of the magnetic dipole magnetic field show that the magnetic magnitude distribution has a hump-shape, whose direction is perpendicular with the antenna axis direction. A localization method based on the hump-shape signal detection is presented. The experimental result shows that the precision can reach a value of ±5 cm. The method can be used to localize a pipeline robot working in a metal pipe.

Visual servo technique of autonomous mobile robot in bended pipe

Presents a visual servoing control method considering the problem of movement of an autonomous mobile robot in a bended pipe. Considering the turning of the robot at bends, a vision based intelligent control system is presented for the coordinated control of three wheels of the robot. The key techniques of the pipeline mobile robot are how to recognize the existence of bended pipe online, how to recognize the orientation of the bend and the curvature of the bend. The paper discusses the image recognition problems based on a CCD vision sensor. For the recognition of existence of bended pipe, the paper studies the image processing problem and provides an image recognition algorithm based on the movement invariant quadrature. For the recognition of orientation of the bended pipe, the paper provides a method based on the characteristics rotating vector and a neural network is utilized to recognize the orientation of the bended pipe. Finally the paper discusses the problem of the curvature recognition of the bended pipe and shows that a genetic algorithm can be used to achieve the optimization.

Point Stabilization of a Tactor-Trailer Mobile Robot

Point stabilization of a Tractor-Trailer Mobile Robot is addressed in this paper. Based on the transformed chained system, a discontinuous feedback control law with high order sliding mode method is proposed. Simulation is carried out to verify the control law and the results show that it can drive the system converge to the origin in finite time.