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Wang Z.,CAS Shenyang Institute of Automation
Optics Express | Year: 2015

In this paper, a method is proposed to measure the shapes of specular surfaces with one-shot-projection of structured laser patterns. By intercepting the reflection of the reflected laser pattern twice with two diffusive planes, the closed form solution is achieved for each reflected ray. The points on the specular surface are reconstructed by computing the intersections of the incident rays and the reflected rays. The proposed method can measure both static and dynamic specular shapes due to its oneshot-projection, which is beyond the capability of most of state of art methods that need multiple projections. To our knowledge, the proposed method is the only method so far that could yield the closed form solutions for the dynamic and specular surfaces. © 2015 Optical Society of America. Source

Wang Z.,CAS Shenyang Institute of Automation
Journal of Optics (United Kingdom) | Year: 2014

As one of the most popular non-contact shape measurement methods, phase shift profilometry has been studied for many decades and has found applications in both the scientific and industrial world. However, its measurement accuracy and noise resistance ability are still widely researched topics. In this paper, a method to determine the phase map by calculating the phases from multiple high carrier frequencies is proposed for phase shift profilometry to measure the object's shape. Four-shifted phases are well designed to yield a closed-form solution, and a combination of the computation results from multiple high frequencies can suppress the prevalent noise effectively. Calibration methods are also introduced for practical implementation. A moving kernel filter calculated from the maximum likelihood estimation is used to suppress the noise further. The experimental results verified the effectiveness of the proposed methods. © 2014 IOP Publishing Ltd. Source

Wang Z.,CAS Shenyang Institute of Automation
IEEE Transactions on Industrial Informatics | Year: 2014

Controlling the welding process by monitoring the weld pool surface becomes more and more popular in robotic arc welding. In this paper, we propose a monitoring system to infer the P-gas metal arc welding (GMAW) weld pool geometry from the reflected laser lines, which are projected onto the specular weld pool and reflected onto a diffusive plane. The parallel straight lines are distorted according to the shape of the weld pool and thus contain the weld pool's shape information. Accurately computing the equations of the imaged laser lines in the world coordinate system is critical for the subsequent weld pool shape estimation. This paper focuses on accurately segmenting and identifying the reflected laser lines and novel image processing algorithms are proposed to fulfill this specific task. Experimental results verified the effectiveness of the proposed algorithms. © 2014 IEEE. Source

CAS Shenyang Institute of Automation | Date: 2013-01-10

The present invention relates to a TDMA access method and device based on multiple access points. According to the problems that the existing method cannot simultaneously satisfy the demands of timeliness and reliability in actual industrial application and has low resource utilization rate, the present invention takes full consideration of the transmission characteristics and industrial automation application characteristics of wireless networks, and provides a TDMA access method and device based on multiple access points. The main ideas of the method in the present invention are: the multi-access point redundant communication manner is adopted to improve system reliability, beacon frames of multiple access points are utilized to perform time synchronization so as to improve synchronization precision, confirmation messages are fed back with regard to reliable access points to reduce the number of retransmissions, and a modularized multi-access point device design method is adopted to lower the difficulties of device maintenance and management.

CAS Shenyang Institute of Automation | Date: 2011-06-09

An indoor testing device for multiple rotor-containing flying objects including a main support having a plurality of linking members, a plurality of mechanical arms, a plurality of trays, and control units of the mechanical arms. The main support is disposed vertically. The mechanical arms are separately disposed on the linking members of the main support with different height. The trays are separately disposed on one end of the mechanical arms for receiving rotor-containing flying objects, and the control units are disposed on the mechanical arms and rotate therewith. The device can be used for the cooperation and coordination test of multiple rotor-containing flying objects and autonomous control experiments of a single rotor-containing flying object. The tests have high stimulation and improve the usability of the experimental results in the actual system.

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