Abstract:With the development of optical precision manufacturing technology，aspheric optical components are widely used in various optical systems.Therefore,high-precision aspheric surface measurement technology is of great significance to aspheric optics manufacture.This paper introduces the aspheric surface testing technique based on interference method.According to the principle of measurement,the null testing and the non-null testing are introduced in detail.Then it summarizes the current situation and the development trend of aspheric testing technology.

Abstract:Sensors have been used in biological detection. The high sensitivity of the sensor chip has become a new research hotspot. Two-dimensional and three-dimensional coupling silicon nitride microcavity sensors are experimentally demonstrated based on the high sensitivity, low cost, and easy integration of the silicon nitride microcavity. The application of the integrated silicon nitride microcavity optical sensor chips in refractive index measurement is studied in detail. A quality factor of more than 16000 at a wavelength of 1550 nm can be obtained in two-dimensional structure and a quality factor of 4000 at a wavelength of 1550 nm can be obtained in three-dimensional structure. It is demonstrated that suspension structure can greatly improve the performance of the device.

Abstract:This article mainly studies on calibration of a microwave sensor which is used to measure the tip clearance, expatiate the principle of measurement and calibration, , and analyze the influence of speed and retraction value on the results of the calibration. The result provides the data for further optimal design and application of the microwave measurement sensor.

Abstract:The theory of measuring the sensor′s pressure was discussed and the requirement of the vacuum degree for the sensor was proposed. The design method of vacuum cavity and the test method of vacuum degree were given out. The effect of different vacuum cavity′s leaking on the sensor′s long-term stability and measurement accuracy was analyzed. At last, we also need to think about the way on how to design the vacuum cavity and the storage methods and the using environment of the sensor.

Abstract:In order to solve the problem of high dew point traceability, this paper developed a portable high-temperature dew point humidity generator. It can not only calibrate various industrial dew-point meters at room temperature to 95 ℃, but also calibrate high temperature and humidity meters with the test chamber and constant temperature environment. The maximum permissible error of the generator is better than 1℃ through contracting with a 373 high temperature dew-point meter at the dew point temperature 95℃.Because of its small size and light weight, this generator is very suitable for field calibration.

Abstract:In the face of the increasingly serious air pollution, the environmental protection department proposed an ultralow emission plan of coal-fired power plants and a series of corresponding standards. This paper presents an UV gas continuous emission monitoring system which was constructed based on differential optical absorption spectroscopy (DOAS) in high temperature with heat traced pipeline. Its technical indicators were as follows: measuring range was 100mg/m3, linear error ≤±1%F.S., deviation at zero point and span point in 24h was ≤±2%F.S., response time was ＜110s. The system was put into the application in ultralow emission plant and compared with the other gas analyzer on non-dispersive infrared method. The results showed that the absolute error was less than 3mg/m3. It indicated that this system was very suitable for ultralow emission of stationary pollution monitored.

Abstract:A three-dimensional (3D) data registration method based on flexible control points is proposed to solve the problem of data registration in the global measurement of large-scale components. This paper introduces the principle and experimental measurement process of stepped 3D data registration method based on machine vision. It avoids the tedious process of pasting marks on the components and improves the measurement efficiency by projecting flexible control points. And the standard ruler and the panel are measured to verify the proposed method in the laboratory. The experimental results show that the method is effective and can meet the field measurement requirements of large-scale components.

Abstract:Milling straight edges is currently a vital standard gauge for the verification items of flatness. Two methods for measuring milling straight edges based on phase shifting interferometer are put forward, whose advantages are non-contact, high sampling density and high accuracy frequency measurement. One is the sub-aperture stitching method; the other is the oblique incidence method. The simplification in verification items was achieved by using standard optical flat directly and long optical flat was excluded in the items. Take Φ150mm phase shifting interferometer and 300mm milling straight edge as an example, this paper introduces the principles and measuring results of the two methods, and gets flatness (sparse points) from the data of phase shifting interferometer to keep to the requirements of the verification regulation. Finally, the author summaries and estimates the uncertainty of measurement in contrast with the verification regulation. The normalized error of the two methods is less than 0.5.

Abstract:Sound source location based on General Cross-correlation can be divided into two parts--time delay estimation and location estimation. Considering the cost and calculation speed, the location system based on GCC receives more and more concern from researchers. This paper provides a new approach to improve the accuracy of location estimation using signals from two microphones. For that reverberation carries information of location of acoustic source, we can separate the detail which contains information of sound source under assumption of knowing coordinate of microphones. This method can be applied to many aspects especially for humanoid robot.

Abstract:Based on the trajectory tracking control of the Unmanned Surface Vehicle(USV), we propose a new trajectory tracking control framework and use fuzzy control and PID to design controllers. Firstly, trajectory tracking control adopts a separate control scheme. To perfect the control structure, we add a speed control. Secondly, the separate control scheme uses a hybrid control mode which consists of track PID control, heading fuzzy control and rudder angle PID control. The speed control use PID control. Finally, we finish simulation experiment and compare the characteristics within or without disturb. The simulation result shows that the new trajectory tracking control framework could complete control objectives quickly and accurately with great robustness.