Optical-electronic autocollimation method is commonly used to measure straightness of precision guides in engineering application. However, the traditional fixed interval optical-electronic autocollimation method is n...Optical-electronic autocollimation method is commonly used to measure straightness of precision guides in engineering application. However, the traditional fixed interval optical-electronic autocollimation method is not suitable for measuring straightness of an air-bearing guide with a long air-bearing bush or a precision straight guide with a long slide-carriage, because the air-bearing bush and the slidecarriage are actually taken as a big bridgeboard bigger than the length of the bridgeboard with the reflector, which is about 1/4-1/2 of total length of the measured guide. If straightness is measured according to the traditional method, only a few points are sampled so that the guide straightness can not be evaluated fully or accurately. In order to solve the problem, an alterable measuring interval method is proposed for straightness measurement based on analyzing the mutual relations and effects among the tilting angle of the reflector, the length of the bridgeboard, the measuring interval and the straightness of the guide. A straightness calculation model is also developed using the method, and the errors stemming from the method proposed are introduced in brief. A precision air-bearing guide with a long air-bearing bush is measured and evaluated using the method proposed, and the actual measurement and evaluation results prove that the method is correct in theory and practical in operation. The method proposed gives an effective and flexible solution to the straightness measurement of the precision guide with long slide-carriage or air-bearing bush in application. It is an extension of the traditional optical-electronic autocollimation method for straightness measurement.展开更多
Currently, daylighting ducts system is widely used as a daylighting device. Generally, daylighting duct system efficiently takes light from outside during the day, and conveys daylight to required location through lig...Currently, daylighting ducts system is widely used as a daylighting device. Generally, daylighting duct system efficiently takes light from outside during the day, and conveys daylight to required location through light duct manufactured by high reflectance mirror. Daylighting duct system can convey daylight to underground space that has no windows opening to external space. Daylighting system is composed of light collection part, light guide part and light emission part. Efficiency of daylighting system is depending on type of each part used in the system. However, it is very difficult to estimate exact light flow in the system considering type of the parts. Authors performed measurement experiments to make clear the light flow with real-size model and miniature model of daylighting duct system. We discussed effect of type of the parts on efficiency of daylighting duct system.展开更多
基金This project is supported by National Natural Science Foundation of China (No.50175081).
文摘Optical-electronic autocollimation method is commonly used to measure straightness of precision guides in engineering application. However, the traditional fixed interval optical-electronic autocollimation method is not suitable for measuring straightness of an air-bearing guide with a long air-bearing bush or a precision straight guide with a long slide-carriage, because the air-bearing bush and the slidecarriage are actually taken as a big bridgeboard bigger than the length of the bridgeboard with the reflector, which is about 1/4-1/2 of total length of the measured guide. If straightness is measured according to the traditional method, only a few points are sampled so that the guide straightness can not be evaluated fully or accurately. In order to solve the problem, an alterable measuring interval method is proposed for straightness measurement based on analyzing the mutual relations and effects among the tilting angle of the reflector, the length of the bridgeboard, the measuring interval and the straightness of the guide. A straightness calculation model is also developed using the method, and the errors stemming from the method proposed are introduced in brief. A precision air-bearing guide with a long air-bearing bush is measured and evaluated using the method proposed, and the actual measurement and evaluation results prove that the method is correct in theory and practical in operation. The method proposed gives an effective and flexible solution to the straightness measurement of the precision guide with long slide-carriage or air-bearing bush in application. It is an extension of the traditional optical-electronic autocollimation method for straightness measurement.
文摘Currently, daylighting ducts system is widely used as a daylighting device. Generally, daylighting duct system efficiently takes light from outside during the day, and conveys daylight to required location through light duct manufactured by high reflectance mirror. Daylighting duct system can convey daylight to underground space that has no windows opening to external space. Daylighting system is composed of light collection part, light guide part and light emission part. Efficiency of daylighting system is depending on type of each part used in the system. However, it is very difficult to estimate exact light flow in the system considering type of the parts. Authors performed measurement experiments to make clear the light flow with real-size model and miniature model of daylighting duct system. We discussed effect of type of the parts on efficiency of daylighting duct system.
