Tan Yuegang

Measurement error of surface-mounted fiber Bragg grating temperature sensor.

Fiber Bragg grating (FBG) sensors are extensively used to measure surface temperatures. However, the temperature gradient effect of a surface-mounted FBG sensor is often overlooked. A surface-type temperature standard setup was prepared in this study to investigate the measurement errors of FBG temperature sensors. Experimental results show that the measurement error of a bare fiber sensor has an obvious linear relationship with surface temperature, with the largest error achieved at 8.1 °C. Sensors packaged with heat conduction grease generate smaller measurement errors than do bare FBG sensors and commercial thermal resistors. Thus, high-quality packaged methods and proper modes of fixation can effectively improve the accuracy of FBG sensors in measuring surface temperatures.

Application of interpolation algorithm in plate structure detection based on Fiber Bragg grating sensing technology

Due to the speed development of the mechanical equipment, it is important to realize the nondestructive evaluation in time to guarantee the safe and reliable operation. Distributed vibration detection is a conventional approach, but it may suffer from the disadvantages that it is complex to arrange a large amount of measuring points. On the other hand, some optimization algorithms are effective for approximate solutions. Taking into these considerations, we proposes a corresponding damage identification method to realize the damage localization by Fiber Bragg grating sensing technology with interpolation algorithm, which can create a simple method to identify the damaged region for the plate structural. In this paper, vibration detection based on some FBG sensors is built up and the optimum parameters are given. On the basis of this, interpolation algorithm is applied into vibration test and the experimental results show that localization method by the interpolation analysis is feasible to damage detection and it has better detection effect for a thin steel plate.

Research and application of embedded technology in remote network monitoring system of coal mine

Aiming at the weakness and deficiency of current coal mine monitoring system, this paper discusses the design and implementation of a platform to remotely monitor and control coal mine production processes over Industrial Ethernet by using the embedded technology. Integrated with each lower computer terminal are S3C2410 microprocessors that can be used for connectivity to the monitoring network effectively. Besides the terminal core S3C2410, the hardware circuits of memory module, Ethernet module, USB module, input and output channels, LCD display module, and RS232 serial module are studied and designed. Additionally, Linux-based application software that facilitates remote monitoring and control of lower computer terminals using Qt/embedded has also been developed. The monitoring system presented in this paper can not only meet the requirements of coal mine production process, but also has a wide range of applications in other industrial monitoring fields.

Mechanical structural damage detection based on distributed measurement

The distributed detection methods for mechanical structural damage have been researched in these years, but there are some key problems existing in operations such as complex calculation, a lot of testing points. Aiming at the existing shortcomings of the distributed mechanical structural damage detection, this paper puts forward a new method by using distributed Fiber Bragg grating (FBG) sensors combining an interpolation algorithm, and predicts damage region through the limited testing points to avoid the deficiency caused by a large number of detection points. On this basis, taking the thin steel plate with four fixed comers as the object of study, the experiment system is set up using some FBG sensors, and its results verify the feasibility of the method with the interpolation algorithm.

Motion Planning of Multi-joint Underactuated Manipulator Based on Trigonometric Function Input

Based on the characteristics of nonholonomic constraints and the principle of nonlinear control, this paper proposes a structural scheme of multi-joint underactuated manipulator and the method of chained form transformation. It also presents the design of a multi-joint underactuated manipulator which can be transformed into a chained-form system and the analysis indicates its underactuated property is decided by its nonholonomic feature. Then a motion planning method based on trigonometric function input is proposed by using the trigonometric function input control method of the chained form system. Finally, the validity of the motion planning is demonstrated by the simulation analysis. This research idea and method can be applied effectively to developing new multi-joint manipulator and is indispensable in exploring the motion planning issue of multi-joint manipulator

Research on Motion Control of Nonholonomic Manipulator Base on Trigonometric Function Inputs

Research on motion control of nonholonomic system is a hot spot. The presence of polynomial input and trigonometric function input have efficiently solved some problems of motional control of nonholonomic system. But, when these methods are put into practice, there are some problems that need to be dealt with. In this paper, a nonholonomic manipulator was built and its kinematics model was deduced. For this nonholonomic manipulator, its kinematics model can be converted into chained system. By analyzing the control method of trigonometric function input in the chained system, it showed the motion character of trigonometric function input, and a conclusion can be drawn that the trigonometric function input can efficiently control the chained system