Liming Xin

Analysis and Design of a Novel Four-axis Plane Laser Welding System

This paper details a novel plane laser welding machine system which combines two large-scale steel blanks superposed together. Several methods are developed in order to solve the technical problems existing in plane laser welding system: It presents major-minor pressing sets which can control the deformation and eliminate the gap effectively; the design of the 4-axis machine which makes the X axis moving in small range and U axis moving in long range in the same direction can improve the precise and dynamic performance of the system. The experimental results show that this new system has potential for future industry application.

Analysis and Research on Mismatch in Tailored Blank Laser Welding

Mismatch is an important quality evaluation standard in Tailor Welded Blanks. The control of mismatch, especially for multi-group blanks, is a difficult technique in Tailored Blank Laser Welding process. In this paper, the production and control of mismatch for multi-group blanks is studied based on a Tailored Blank Laser Welding system. The origins of the mismatch are obtained after numbers of experiments: the deformation of the blanks before welding, the intensity of the clamping force, the uniformity of the clamping force, the deformation of the clamping beam, the flatness error of the based platform and the welding process. A mathematical model is established according to the analysis of the origins producing mismatch. Experimental results indicate that the model provides an effective theory in increasing welding quality.

Analysis and research on mismatch in Tailored Blank Laser Welding for multi-group

Mismatch is an important quality evaluation standard in Tailor Welded Blanks. The control of mismatch, especially for multi-group blanks, is a difficult technique in Tailored Blank Laser Welding process. In this paper, the production and control of mismatch for multi-group blanks is studied based on a Tailored Blank Laser Welding system. The origins of the mismatch are obtained after numbers of experiments: the deformation of the blanks before welding, the intensity of the clamping force, the uniformity of the clamping force, the deformation of the clamping beam, the flatness error of the based platform and the welding process. A mathematical model is established according to the analysis of the origins producing mismatch. Experimental results indicate that the model provides an effective theory in increasing welding quality.

Error modeling for tailored blank laser welding machine

This paper introduces the research on error modeling of tailored blank laser welding machine which has four linear axes. The error models are established based on multi-body system (MBS) theories which are developed in this paper. The number arrays of low-order body are used to describe the topological structures which are taken to generalize and refine MBS, and the characteristic matrices are employed to represent the relative positions and gestures between any two bodies in MBS. Position error associated function which can reflect the influence of each error origin on the positioning error of the machine tool is given to describe transmission error of the machine in detail. Based on this method, the paper puts forward the error model of the tailored blank laser welding machine. The measurement and evaluation of their error parameters start, after complete error modeling of the machine. Leica Laser Tracker is introduced to measure the errors of the machine and to check the result of the error model.

Gravity balance technique of the docking ring in the spacecraft docking testbed

To simulate the zero-gravity activities of the docking ring in a spacecraft docking testbed, a gravity balance device with high respond speed and high precision was designed. Mechanism scheme and working principle of the gravity balance device are introduced. The characteristics of the follower mechanism, which may interfere with the gravity balance system, are analyzed in detail. The accuracy of the gravity balance system is experimented. Analysis and experiment results show that the gravity balance device meets the requirements on friction resistance and inertia resistance. The precision of the gravity balance reaches 1.1%.

Analysis and research on the boost power plant of spatial docking platform

This paper presents a novel boost power plant with high dynamic performance. In the experiment of spacial docking,This boost power plant plays as the motor of the aerial vehicle. The mechanism and the principle of the boost are described and the response time of the air-operated system is computed to prove the characteristic of quick-response. The Analysis of the boosting process demonstrates the boosting force and the position and attitude of the boost power plant keeping in the same direction in real time. The boost power plant which has the characteristics of novel structure, quick-response and high precision is a mechanism for special application.

Error modeling for five-axis laser processing robot

This paper introduces the research on error modeling of a five-axis laser processing robot which has three linear axes and two rotational axes. The error models are developed based on vector/matrix notion. Homogeneous coordinate transformations are employed to represent the ideal and real linearrotation transformations of the five-axis laser processing robot by considering small angular approximation. Position error associated function which can reflect the influence of each error origin on the positioning error of the machine tool is given to describe the transmission error of the robot in detail. Based on this method, the paper puts forward the error model of the five-axis laser processing robot.

Error Modeling of A New Kind of Plane Movement Position and Attitude Measuring Equipment

This paper presents a new kind of measurement mechanism for the position and attitude measurement of the moving object in a plane. The mechanism and the measurement principles are described and the error models are built by using differential law principles. Analysis practical applying and the simulation demonstrate the feasibility of the method. This mechanism with characters of high precision and simple is applicable to high-precision and large-space plane movement measurement under some special measurement conditions.