Compact four-light-spot two-dimensional corner detection device combined with laser triangulation method

Abstract

The invention discloses a compact four-light-spot two-dimensional corner detection device combined with a laser triangulation method, which comprises a laser, a one-to-two beam splitting unit, a two-to-four beam splitting unit and a photoelectric detection unit, the one-to-two beam splitting unit comprises a half-wave plate I, a polarization beam splitting prism I, a quarter-wave plate I, a quarter-wave plate II, an isosceles right-angle prism I and an isosceles right-angle prism II; the two-to-four beam splitting unit comprises a half-wave plate II, a polarization beam splitting prism II, a quarter-wave plate III, a quarter-wave plate IV, an isosceles right-angle prism III and an isosceles right-angle prism IV, and the photoelectric detection unit comprises a detected plane, an imaging lens, a CCD camera and a computer. According to the invention, the measurement sensitivity is adjusted by moving the isosceles right-angle prism, the measurement result is not influenced by the vibration of an object, and the measurement range is large; a reflector or a mark point does not need to be mounted on an object, the operation is convenient, and ideal non-contact measurement can be realized; the device is simple and compact in structure and low in cost.

Description

technical field [0001] The invention relates to the technical field of optical measurement and mechanical quantity measurement, in particular to a compact four-spot two-dimensional rotation angle detection device combined with laser triangulation. Background technique [0002] Two-dimensional rotation angle is a very important geometric parameter in measurement. With the continuous development of science and technology in today's society, the measurement methods of two-dimensional corners are also constantly improving. Compared with traditional mechanical goniometric methods, optical measurement methods have the characteristics of non-contact measurement and high precision, such as circular grating method, laser interferometry, laser alignment method and laser triangulation method. Among the optical measurement methods, the circular grating method measures the rotation angle by measuring the number of grating pitches that the grating rotates, which has good stability and hi...

AI Technical Summary

Problems solved by technology

Among the optical measurement methods, the circular grating method measures the rotation angle by measuring the number of grating pitches that the grating rotates, which has good stability and high precision, but it has high requirements for equipment installation and grating accuracy, and it is difficult to guarantee the resolution; the laser interferometry measures the rotation angle of the object The optical path difference converted into coherent light waves has high measurement accuracy, but the measurement results are easily affected by environmental vibration and airflow, and are only suitable for small-angle measurement, and the measurement range is small; the laser collimation method is based on the principle of optical self-collimation, and requires The reflector is installed on the top, and the collimated beam is reflected by the measured object to measure the rotation angle, which is also suitable for small angle measurement, and the measurement range is limited; the laser triangulation method is to inject a beam of laser light on the surface of the measured object, and then use the CCD The camera images the light spot on the surface of the object from another angle, and obtains the rotation angle parameter by calculating the spot displacement. Because there is a certain angle between the optical axis of the laser and the optical axis of the camera, it is called laser triangulation. Good sex and other characteristics

In order to avoid the influence of the vibration of the measured object, at least two parallel light beams are generally required to generate two light spots in practical applications. In this case, only one-dimensional rotation angle can be measured. Further, the method of generating four light spots by four parallel light beams can Measuring two-dimensional rotation angles, such as the current tilt angle measurement system based on laser triangulation, uses double-wedge mirrors to form four beams that are approximately parallel to detect the tilt angle and direction. Since the four beams formed by the system are not strictly parallel, they are used When the distance between the measured object and the measuring system changes, it will affect the measurement result of the inclination or rotation angle

Images