Research On Multimode Measuring Approach Of Triangular Laser Displacement Sensor

Triangular laser displacement sensor is a non-contact measurement sensor based on photoelectric principle,which is widely used in the field of geometric sense detection and displacement measurement.However,due to the limitations of measurement principle and structure,this kind of sensor can't change the measuring direction in real time according to the measuring object.In addition,there is a conflict between the measuring range and the measuring accuracy.When the measuring range is large,the measuring accuracy is generally low.And when the measuring accuracy is high,the measuring range is small.The problems above have limited the application of triangular laser displacement sensor in the measurement of complex surface.In this paper,a CMM is used as a platform to study the method of triangular laser displacement sensor to change the measurement direction in real time and adjust the measurement range instantly.For the problem of changing the direction while measuring,by adding magnetic mirrors for the sensor to achieve beam projection direction changing.So that the sensor does not change the pose of the premise,achieve the sensor to measure a number of different directions.Aiming at the contradiction between measuring range and measuring accuracy,a method of measuring range is proposed.In this method,the measuring optical path on the periphery of the sensor is biased by the combination of mirrors so as to expand the measuring range of the sensor.With three different mirror combinations,you can get three equal magnification range to meet the needs of different measurement ranges.On the measurement method,two step progressive measurement methods are studied.Based on the large-scale measurement data after the optical path is biased,the measurement path is planned for the small-range measurement without optical path offset,so that the complex curved surfaces could be Fast and accurate measurement.At the same time,aiming at the contradiction between measuring range and measuring accuracy,a hybrid measuring method is studied.Based on the original laser displacement sensor,an additional photoelectric position detection device(CCD)is added.The CCD and the laser from displacement sensor form an auxiliary displacement measurement sensor with a relatively large measuring range.During measurement,when the object exceeds the range of the laser displacement sensor,the auxiliary device promptly guides the Z axis of the CMM to adjust the position in the vertical direction according to the measurement signal,so that the object returns to the range of the laser displacement sensor.Achieve the rapid measurement of complex surfaces.Combined with theoretical research,an experimental system was set up to verify the multi-mode measurement method described in the paper.The experimental results show that in the process of measuring complex objects,the multi-mode measurement method described in this paper can accurately and quickly obtain the measured data of the measured surface and provide the technical guide for the rapid and precise measurement of the complex profile.