Research On Laser Alignment Based On Interference Fringe

With the development of modern science and technology, people call for a highermeasurement accuracy of geometric parameter. Being a factor of shape measurementerror, straightness can affect the accuracy, performance and quality directly. Insomeway it even could be the governing factor. Therefore, straightness measurementis the most basic and important measurement.Utilizing its wavelength stabilization, strong coherence and well directionalproperty, laser collimator display a prodigious effect in the realm of straightnessmeasurement. But the accuracy of laser collimator is hard to increase for the influenceto laser beam in the atmosphere.In the continuous research for higher measurement accuracy, scientists takevarious effective means and new technique to against the disadvantage factors met instraightness measurement. The dissertation studies history and actuality, and itanalyses and compares the merits and shortages of many kinds of laser collimation.With references of others' production, we put forward a new method of lasermeasurement system based on interference fringe.After collimated and broadened, the semiconductor laser beam exposure on thewedge-shaped plate. Because of the reflection on the two surfaces of thewedge-shaped plate, the laser beam become two cross beams of 2α cross angular.The interference fringe appears in the cross region of the two beams. Make thisinterference beam to be the measuring basis, and fix the linear CCD on the receivingtarget. Detect the interference beam position on the receiving target, and then we canget the distance between the measured point and the measure basis.The measurement system utilizes the recent results of modern electrontechnology, optics technology, the sensor and MCU technology to develop the opticsmeasure system, signal acceptance and disposal system, MCU and software system.We have taken necessary measures of all sorts to improve SNR and measure precisionof the device instrument. Through the comparison test, system stability and reiterationtest of the model instrument in contrast to photo-electricity autocollimator, and the airagitation test, the results indicate that the performances have met the scheduledtargets.