Ye Yanhui

Kinematical modeling of mobile welding robot for lattice type seam tracking

For the automation of lattice type seam welding in building ship, an autonomous mobile robot system is developed in this paper. The robot is composed of two driving wheels, a horizontal torch slider, a vertical torch slider and a rotational arc sensor. Tracking errors are detected by the rotational arc sensor. The kinematics model of the mobile robot is established firstly, and then the moving path of the robot at the corner is planned based on the kinematics mode, and the trajectory and velocity of the welding gun is analyzed. A fuzzy controller based on the planned trajectory and tracking errors is designed. The simulation and experiments have been done to verify the effectiveness of the proposed controller.

Study on Characteristics of High-Pressure Precision Flow Valve of Metal Rubber

A new type of precision flow valve is designed by used the combination of piezoelectric ceramic and metal rubber, the mathematical model that possesses flow characteristics at the valve outlet is established based on Darcys law and Newtons first law, the influence of different driving voltage and different parameters of metal rubber ring on flow characteristics is analyzed through using MATLAB software, and the effects of metal rubber ring on the flow stability of fluid in the valve outlet is analyzed on simulation by means of FLUENT software. The results show that: the flow characteristics of valve are related to the driving voltage of the piezoelectric ceramic and the parameters of metal rubber ring After the metal rubber ring is installed at the valve outlet, the fluid flow at the valve exit is gentler. The flow direction of fluid tends to be consistent, which is approximate to the laminar flow. To a certain extent, it improves the stability of the valve output flow (pressure).

Stable tracking control of autonomous welding mobile robots based on kinematics model

This paper proposes a stable tracking control law for mobile platform and welding torch of Autonomous Welding Mobile Robot used in shipbuilding and large spherical tank welding. Stability of the law is proved through the use of a Liapunov function. Not only the moving and rotating velocity of the robot is controlled, but also the moving velocity of the cross slider is controlled. In the simulation, we analyze the effects of different control parameters in line tracking problem. And the tracking response in circle-line tracking problem is also presented. It is shown that the output responses represent non-oscillatory property and effectiveness of the tracking law.