JPH02293609A - Angle measuring instrument - Google Patents

Abstract

PURPOSE:To measure dynamic angles with a high accuracy by making a laser beam incident to an object to be measured by a rotary mirror with an angle detector, detecting the reflected light with a two-dimensional sensor and generating a pulse when the object to be measured and the mirror are parallel. CONSTITUTION:The laser beam 8 of a laser device 1 is made incident via the rotary mirror 3 having the angle detector 10 with a motor to the material 5 to be measured and the reflected light 20 is made incident to the two-dimensional sensor 6. A reference pixel 11 is irradiated with this light. The pulse is emitted when the reference pixels 11, 12 align at the point of the time when the rotary mirror 3 and the material 5 to be measured parallel with each other. The pulse is then generated from the reference pixel 12 when the material 5 to be measured is rotated and only when the rotating angle of the material 5 to be measured and the angle of the rotary mirror 3 are equal. The instantaneous angle of the material 5 to be measured is known from the angle data of the angle detector 10 of the rotary mirror 3 at the point of the time when this pulse is outputted.

Description

DETAILED DESCRIPTION OF THE INVENTION [Field of Industrial Application] The present invention relates to an angle measuring device, and more particularly to an angle measuring device for measuring the angular characteristics of a rotating or reciprocating device. [Prior Art] Conventionally, the angle of rotating or reciprocating equipment has been measured using an angle detector such as an encoder attached to the rotating shaft. In addition, measurements were performed using a laser beam or a collimator as a non-contact angle measuring device to the object to be measured. [Problems to be Solved by the Invention] The conventional angle measuring device described above is capable of highly accurate angle measurement when the object to be measured is stationary, but when the object to be measured is rotating or in particular has reciprocating rotational vibration. In this case, there are disadvantages in that the moment of inertia of the angle detector acts as a load and twisting occurs in the rotating shaft, resulting in errors in the angle measuring device.

Furthermore, conventional angle measuring devices can only measure angles in the direction of rotation, and have the disadvantage of being unable to detect distortions of the object to be measured, such as bending of the rotating shaft. In addition, conventional angle measuring devices using laser beams and collimators can measure accurate angles and distortions of objects to be measured, but they generally only measure fixed angles and do not measure dynamic angular characteristics.
It is impossible to process. [Means for Solving the Problems] An angle measuring device of the present invention includes a laser device, a half mirror that separates the laser beam of the laser device into first and second laser beams, and a half mirror that separates the laser beam of the laser device into first and second laser beams. a rotating mirror that reflects and rotates to generate a third laser beam; an angle detector with a motor that rotates the rotating mirror at an arbitrary number of rotations and detects a rotation angle; and the second laser. 2. Receive the fourth laser beam that has been irradiated onto the object to be measured and reflected the third laser beam, and generate a pulse when the reception phases of the third and fourth laser beams match. It has a dimensional sensor, and a computer that calculates the angular characteristics of the object to be measured from the data of the motorized angle detector and the output pulses of the two-dimensional sensor. [Example] Next, the present invention will be explained with reference to the drawings. FIG. 1 is a block diagram of an embodiment of the present invention. Figure 2 is an explanatory diagram of the main parts of Figure 1, the half mirror and the two-dimensional sensor. The embodiment shown in FIG. 1 is an object to be measured that is rotated reciprocally by a motor 7. 5, which includes a laser device 1, a half mirror 2, a rotating mirror 3 that rotates at an arbitrary number of rotations, and an angle detection device with a motor that rotates the rotating mirror 3 at an arbitrary number of rotations and detects the angle of the rotating mirror. vessel 10, half mirror 2
A fixed mirror 4 for reflecting one of the laser beams 8 separated by and setting a reference position for the irradiation position of the two-dimensional sensor 6, a vertical reflection mirror 9 for vertically reflecting the laser beam 8, and a motorized It consists of an angle detector 10 and a computer 11 that calculates and processes the angular characteristics of the object from the output pulses of the two-dimensional sensor 6. Next, FIG. 2 is an explanatory diagram for measuring the angle that changes with time of the laser beam reflected from the object to be measured 5 that rotates back and forth at each time point of the rotating mirror 3, which is known in advance. First, with the object to be measured 5 in a stopped state, the fixed mirror 4A,
4!3, the reflected light 20 of the laser beam 8 from the object to be measured 5 is transmitted through the half mirror 2 and irradiated onto the reference pixel 11. In this state, rotate the rotating mirror 3 at an arbitrary rotation speed. The reflected light 21A from the rotating mirror 3 is re-reflected by the half mirror 2, and the reflected light 21B is irradiated onto the two-dimensional sensor 6 to obtain a laser beam irradiation trajectory 13. When the rotating mirror 3 and the object to be measured 5 become completely parallel, the two-dimensional sensor 6 emits a pulse when the reference pixels 11 and 12 are aligned with the hatched A line on the two-dimensional sensor 6 surface. Next, when the object to be measured is rotated, when the rotation angle of the object to be measured 5 and the angle of the rotating mirror 3 are equal, that is,
Only at the moment of parallelism, a pulse is generated from the reference pixel 12 as described above. The instantaneous angle of the object to be measured 5 can be determined from the angle data output from the motorized angle detector 10 driving the rotating mirror 3 at the time this pulse is output. In this case, the pulse output when the object to be measured 5 is stopped is defined as the O point of the angle, and the time point at which the object to be measured 5 starts rotating and the pulse is output from then on and the angle of the motorized angle detector 10 are is stored in the computer 11. The processing unit in the computer 11 can also process constant speed rotation and non-linear angular velocity calculations from the time and angle data at this point. Next, in the case of measuring a non-linear angular velocity, the measurement of the angle in the case where the movements of the rotating mirror 3 and the non-measurable object 5 are asynchronous will be explained with reference to the explanatory diagram of FIG. Now, the object to be measured 5 is reciprocatingly rotated, and the non-linear rotational motion is defined as the actual angle characteristic 18,
The angular characteristics of the rotation mirror 3 in one direction are shown in 17A. 17B
Suppose that In the case of angular characteristic 17A, at the angle reference point A and the intersection of B and C, the times ta, tb, to and the angle θ
＾(=0°)θ8. θC, is found. Actual angle characteristics 1
8 in more detail, use rotating mirror 3.
By finding the intersection of B' and C' as the angular characteristic 17, times tb' and t and angles θB and θC' can be obtained. By making the rotation of the rotating mirror 3 asynchronous in this way, it is possible to measure the time difference and angle at any angle of the object to be measured, and by performing statistical processing on the computer 11, the angular characteristics of the object to be measured can be measured in detail. can do. Note that the automatic angle characteristic measuring device according to the present invention is non-contact and does not apply any load to the object to be measured 5.
Furthermore, the measurement precision is determined by the accuracy of the angle detector of the rotating mirror 3, and it is possible to improve the measurement precision by statistical processing.

Further, the automatic angle characteristic measuring device according to the present invention is capable of highly accurate measurement of rotational blur due to distortion of the object to be measured 5 by detecting the output of pixels other than the reference pixels of the two-dimensional sensor 6.

〔Effect of the invention〕

As explained above, the present invention uses a laser device, a rotating mirror with a known rotation angle that rotates at an arbitrary number of rotations, an angle detector with a motor that rotates the mirror, and a two-dimensional sensor to move the object to be measured. The present invention has the advantage that it is possible to provide an angle measuring device that can measure rotational angle characteristics of a target with high accuracy in a non-contact manner.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram of an embodiment of the present invention, FIG. 2 is an explanatory diagram of a half mirror and a two-dimensional sensor portion, which are the main parts of this embodiment, and FIG. 3 is an explanatory diagram of this embodiment. 1...Laser device, 2...Half mirror 3...
・Rotating mirror, 4A, 4B...Fixed mirror 5...
Object to be measured, 6... Two-dimensional sensor, 7... Motor
8...Laser light, 9...Vertical reflection mirror, 10.
...Angle detector with motor, 11.12...Reference pixel, 13...Laser light irradiation trajectory,

Claims (1)

[Claims] a laser device; a half mirror that separates the laser beam of the laser device into first and second laser beams; and a rotation device that reflects and rotates the first laser beam to generate a third laser beam. a mirror, an angle detector with a motor that rotates the rotary mirror at an arbitrary number of rotations and detects the rotation angle, and a fourth laser beam that irradiates the object to be measured with the second laser beam and reflects it. receiving the third laser beam;
A two-dimensional sensor generates a pulse when the reception phases of the third and fourth laser beams match, and the angular characteristics of the object to be measured are determined from data from the motor-equipped angle detector and output pulses from the two-dimensional sensor. An angle measuring device characterized by having a computer that calculates and processes.