The high-speed data acquisition equipment which is based on NI and LabVIEW software was used to establish the acoustic emission (AE) signal collection platform, and adopted wavelet analysis method to extract the weak of AE signal waveform from noise, aiming at the localization of AE source on plywood surface. The signal cross-correlation analysis method is used to determine the time difference between the AE signals and the different sensors,so that further calculates the average propagation speed of AE signal on the plywood surface. A kind of AE signal source localization method which is based on the cross-correlation method was proposed according to the principle of geometric positioning, and verified by means of the testing experiment which selected the lead break to simulate AE source. This paper has shown that wavelet analysis can effectively extract AE signal waveform, and the localization method based on cross-correlation principle can precisely calibrate the position of AE signal source.

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With the continuous development of intelligent robotics, intelligent robot can realize autonomous moving. Robot simultaneous localization and mapping technology arises at the historic moment. Adaptive monte carlo localization algorithm was used for mobile robot pose estimation. Bayesian algorithm was used to building grid map. The robot moving path was computed by the path planner algorithm. The mobile robot follows the path and realizes autonomous moving function. ROS platform was used for tracked mobile robot to realize the SLAM technology. Compared with conventional software development platform, ROS have strong focus on usability and ease of installation and have the advantages of free and open source. The experimental results demonstrated that ROS platform could greatly shorten the development cycle of the robot and the SLAM could easily realize on ROS, the robot can realize autonomous moving. 

Taking an aluminum tank semitrailer as an example, this essay aim to analyze the strength and stiffness of the tank semitrailer and obtain stress and strain characteristics under different conditions on the basis of a finite element model, by using the finite element analysis software. By carrying on modal analysis in different work conditions, the essay gets the dynamic performance parameters of the tank. The results show that the tank fully meets the requirements of using, and the performance parameters of the tank will be foundation for the optimization.

Purpose Since robot’s structural stiffness is usually less than 1 N/µm, mode coupling chatter occurs frequently during robotic milling process, and chatter frequency is close to the natural frequency of the robot itself. Chatter not only affects the surface quality but also damages the robot and reduces the positioning accuracy. Therefore, it is necessary to predict chatter in robotic machining process. Design/methodology/approach A three-dimensional dynamic model for robot’s spatial milling plane is established, and a corresponding stability criterion is obtained. First, the cutting force in milling plane is transformed into the coordinate system of the robot principal stiffness direction based on homogeneous transformation matrix. Then the three-dimensional stability criterion under milling process can be obtained by using system stability analysis. Furthermore, the circle diagram of mode coupling chatter stability is drawn. Each feeding direction’s stability under the two processing forms, referred as spindle vertical milling and spindle horizontal milling, is analyzed. Findings The experimental results verify that the three-dimensional stability criterion can avoid chatter by selecting machining feed direction in stable area. Originality/value This paper established a three-dimensional dynamic model in robot’s spatial milling plane and proposed a three-dimensional stability criterion according to the Routh criterion. The work is also expected to be an efficient tool in the development of robotic milling technology.