Abstract:A low temperature drift and low voltage bandgap reference is designed for a new uncooled infrared focal plane array (IRFPA) readout circuit. The technique which can be used to provide both reference voltage output and reference current output is proposed. By modifying the bandgap load and reference core circuit in the bandgap reference circuit, the reference voltage and current can be compensated for temperature respectively. When using a 0.5 μm N well CMOS technology, simulation is carried out by using the Spectre software. The result shows that the temperature coefficients of the voltage output and the current output are 35.6 ppm/℃ and 37.8 ppm/℃ respectively in the temperature range from -20 ℃ to 100 ℃ at 3.3 V. The power-supply rejection ratio (PSRR) is -68 dB at DC. The circuit can operate in the range from 2.2 V to 4.5 V.

Abstract:The way to expand the field of view (FOV) of an optical system by using the principle of image rotation scanning is analyzed. An optical design model which uses a secondary imaging structure is established. By using a Pechan prism as a one-dimensional scanning device and tilting a cooled mid-wavelength infrared detector, the exit pupil of the optical system and the cold stop of the detector are fully matched. In addition, to ensure the imaging quality at different temperatures, a passive optical athermal technology is used. The model has a relative aperture of 1∶3, a wavelength of 3.7 μm to 4.8 μm, a focal length of 34 mm and a FOV of ? 20?. By using eight lenses among which two are aspheric, the imaging quality close to the diffraction limit is obtained in the whole FOV.

Abstract:The causes resulting in the nonuniformity in a MOS resistor array are analyzed and a new nonuniformity correction method which can obviously improve the quality of the generated infrared scene is proposed. When the MOS resistor array is tested offline, the voltage vs temperature data and the voltage vs temperature data to be corrected are measured. Then, by taking these raw data as the input of a neural network, the functional relationship between the pre-correction input and the expected input of each element in the resistor array is established. Finally, a look-up compensation table which can be used to reduce the nonuniformity due to the different responsibility of each element in the MOS resistor array is generated. The simulation result shows that this method is feasible and its correction effectiveness is greatly improved in comparison with the conventional piecewise linearization method.

Abstract:Using infrared thermography to detect the surface temperature distribution of a motor is of great significance to the study of the relation between the surface temperature distribution of the motor and the working current of the motor stator. It is helpful to the quick and effective finding of the potential accident and fault of the motor in operation. A steady heat transfer mathematic model is established for a three-phase asynchronous motor by using a finite volume method. The function specification method in the inverse heat transfer problem is used to estimate the current of the stator in a Y100-L2 motor and the influence of the measurement error of the motor surface temperature on the current estimation error is analyzed. The result shows that it is feasible to use infrared thermogarphy to measure motor surface temperature and estimate the working current of a motor. The measurement accuracy of the infrared thermography can meet the practical requirement.

Abstract:To meet the needs of seamless infrared image mosaic, a grayscale nonuniformity correction algorithm based on infrared image sequences is proposed. In this method, the relative stability of the grayscale nonuniformity area is used and the grayscale correction template is obtained by calculating the average of a lot of infrared image sequences. Then, the grayscale correction template is used to correct each frame of the image sequences and the grayscale uniformity of the pixels under the same illumination is achieved. Finally, the mosaic test is carried out on the infrared video image sequences captured by a HJRG-001 infrared thermal imager and the SURF algorithm is used to mosaic the corrected image sequences. The experimental result shows that this method is simple and fast. It can effectively correct the image nonuniformity caused by the imaging system and eliminate the mosaic seams while keeping good image definition.

Abstract:It is an effective method to use the invariant moment features for target recognition. By comparing the features and applicable conditions of the Hu moment, affine invariant moment and wavelet invariant moment, a method in which the combination of partial Hu moment, affine invariant moment and wavelet invariant moment is used to recognize ship image targets is proposed. The simulation result shows that the combined moments are effective for the improvement of the recognition of ship image targets.

Abstract:Both FLUENT numerical simulation and experimental simulation are used to calculate and simulate the thermal wake buoyant process of an underwater vehicle discharging hot water in the sea water with uniform and vertical temperature gradient and the correlation of it with the surface. The laws of the surface temperature change caused by the underwater vehicle are obtained. Then, the test result of the thermal wake is compared with the numerical simulation result. In addition, the infrared images of thermal wake buoyant process and surface are obtained. This study provides a certain theoretical basis for the detection of underwater vehicles.

Abstract:An infrared differential thermal detector for asphalt pavement permeability is developed. The detector is based on a high speed infrared detector system and a software system including infrared surface temperature measurement, signal conversion, chromatography, etc. It is the first infrared differential thermal detector which can continuously operate at a speed of 100 km/h in the field of asphalt pavement permeability measurement. The research result shows that it is feasible to evaluate the permeability of asphalt pavement by measuring the surface temperature difference of asphalt pavement with the infrared temperature measurement technology. Compared with the traditional fixed-point permeability detector, its detection effectiveness is improved by a factor of 50 and its correlation coefficient is up to 0.8985. Because the system can share the pavement permeability information with an intelligent fog seal asphalt distributor, it can form a complete asphalt pavement permeability treatment technology which meets the requirements of different highways in China.

Abstract:Progress, sample preparation and application of infrared spectrometry in the field of polymer materials are presented in brief. Because of the advantages of quick and convenient detection, the infrared spectrometry plays an important role in the study of polymer materials. The application prospect of the infrared spectrometry in the field of polymer materials is given.