CN115752239B

CN115752239B - Motion mechanism synchronism measuring device and measuring method thereof

Info

Publication number: CN115752239B
Application number: CN202211497498.8A
Authority: CN
Inventors: 沈斌; 王廷; 罗一钧; 谢非凡
Original assignee: Hangzhou Laizhi Measurement Technology Co ltd; Hangzhou Guangchi Technology Co ltd
Current assignee: Hangzhou Laizhi Measurement Technology Co ltd; Hangzhou Guangchi Technology Co ltd
Priority date: 2022-11-25
Filing date: 2022-11-25
Publication date: 2023-06-27
Anticipated expiration: 2042-11-25
Also published as: CN115752239A

Abstract

The invention relates to the field of high-precision measurement of bilateral or multilateral synchronicity of a linear motion mechanism. When the synchronization measurement is carried out, one side of the guide rail is used as a reference shaft, the laser transmitter frame is firstly fixed, the laser beam is adjusted to be parallel to the reference shaft, then the laser beam is deflected by 90 degrees to the measured shaft on the other side through the pentaprism arranged on one side of the reference shaft, a double-shaft PSD sensor for receiving the laser beam is arranged at the position, when the workbench or the portal frame moves, the position of the laser beam on the PSD sensor is changed due to the asynchronism of the two sides, the change can be accurately measured by the PSD sensor, the data is processed and analyzed, and therefore the synchronization error can be further compensated. The method is characterized in that the synchronicity error is obtained by measuring the relative change quantity of the two sides or the multiple sides instead of the absolute movement quantity, and compared with the traditional measuring method, the method has the advantages of high precision, simplicity in operation, strong applicability and the like.

Description

Motion mechanism synchronism measuring device and measuring method thereof

Technical Field

The invention relates to the technical field of high precision of synchronous error measurement of a linear motion mechanism, in particular to a synchronous error measurement device based on a PSD sensor.

Background

Equipment with portal frame (bridge frame) movement such as large-scale portal machine tools and three-coordinate measuring machines, or equipment with a moving platform arranged on parallel guide rails on two sides; due to the factors of parallelism error of the two guide rails, asynchronism of motors at two sides and the like, the motion mechanism can generate torsion pendulum during motion, and further, synchronization error at two sides is generated; the larger the span of the two side rails, the larger the resulting synchronization error.

The traditional method for measuring the synchronism error mainly comprises a metering method, an interferometer method and the like. The surface beating method is suitable for a small-span movement mechanism, and the movement speed is low or the situation of static measurement; the method has low cost and higher measurement efficiency, but the measurement accuracy and applicability are not ideal.

The interferometer method is divided into a double interferometer method and a spectroscopic method, wherein the double interferometer method generally uses two single-frequency laser interferometers to measure the synchronization error, and the double-frequency laser interferometers can use the spectroscopic method to measure; the interferometer method has high measurement precision, but has lower measurement efficiency and higher price cost of equipment.

Disclosure of Invention

(one) solving the technical problems

Aiming at the defects of the prior art, the invention provides a motion mechanism synchronism measuring device based on a PSD sensor, which has the advantages of high precision, simple operation, strong applicability and the like, and solves the problems of low measuring efficiency, high cost and the like of the traditional measuring method.

(II) technical scheme

In order to solve the technical problems, the invention provides the following technical scheme:

the motion mechanism synchronism measuring device comprises a laser transmitter, a pentaprism, a PSD sensor and a data processing terminal; the laser transmitter is fixed at one end of the reference shaft, and can adjust the laser beam to be parallel to the reference shaft, wherein the laser beam is a measured reference; the pentaprism is arranged on the movable workbench or the movable portal frame, and the installation position is as close to the reference shaft as possible and is used for transmitting the reference standard; the PSD sensor is arranged on the movable workbench or the movable portal frame, is close to the detected shaft and is used for receiving the laser beam and outputting data of the relative displacement variation.

The measuring method of the motion mechanism synchronism measuring device comprises the following steps: s1, erecting a laser emitter on a lathe bed or an external tripod at one end of a reference shaft, setting two measurement reference points at the moving proximal end and the moving distal end of the reference shaft, and adjusting an adjusting knob of the laser emitter to enable data trend of a PSD sensor at the two reference points to be consistent, so that the laser is parallel to the reference shaft; after the step is completed, a reference datum for measurement is determined, and the laser transmitter needs to be kept stationary; s2, installing a pentaprism at a position of a portal frame or a workbench, which is close to a reference shaft, so that the laser beam is deflected by 90 degrees and is emitted to a tested shaft; during measurement, the pentaprism moves along with the portal frame or the workbench; s3, installing the PSD sensor at a position close to a detected shaft on a portal frame or a workbench, and adjusting the position of the PSD sensor to enable a laser beam to be incident into the center position of the PSD sensor; at the moment, the PSD sensor can measure the accurate position of the laser beam at the sensor and transmit data to the data processing terminal through wireless Bluetooth; zeroing the position data when measuring the first position; s4, moving the portal frame or the workbench, and recording the generated position data; s5, inputting the acquired data to a data processing end, and adjusting relevant parameters of a motor control system for driving the portal frame or the workbench according to a calculation result to correct the synchronism error; s6, repeating the steps S4-S5 until the measured synchronism error is smaller than a set threshold value.

Preferably: in the scheme, the direction of the reference axis is X1; the direction of the detected axis is X2; the direction of the laser beam reflected by the pentaprism is Y; the X1 direction is perpendicular to the Y direction through the guarantee of a pentaprism; the structure and principle of the pentaprism ensure that the perpendicularity between the outgoing laser beam and the incoming laser beam is hardly affected by the change of the incident angle of the laser beam caused by the change of the posture of the pentaprism; meanwhile, a small round reflecting mirror for indicating and adjusting the position and angle of the incident laser beam is designed in front of the incident surface of the pentaprism.

Preferably: when the portal frame or the workbench is twisted on the guide rail, the Y direction is still vertical to the detected shaft X2, but the detected shaft of the portal frame or the workbench is deviated from the reference shaft in the front-back position in the moving direction, and the deviation is the synchronism error of the two sides, and the reading on the PSD sensor is delta X.

Preferably: when the number of the guide rails is greater than two, after one axis is selected as a reference axis, the synchronization error measurement of the multiple guide rails is completed by adding a pentaprism and a PSD sensor measuring unit.

(III) beneficial effects

Compared with the prior art, the invention provides a PSD sensor-based synchronicity error measurement method, which has the following beneficial effects:

according to the method for measuring the synchronism error, a laser beam parallel to a reference axis is refracted to another measured axis through a pentaprism, and the function of the method is to transfer the position of the reference axis to a PSD sensor of the measured axis. When the synchronization error is generated, the position of the reference shaft recorded on the PSD sensor is changed, the corresponding error is transmitted by the PSD sensor in real time and is calculated and analyzed by the data processing terminal, and compared with the traditional method, the method is simpler to operate and greatly improves the measurement precision.

Drawings

Fig. 1 is a schematic structural diagram of a device for measuring the synchronism of a moving mechanism.

Fig. 2 is a schematic structural diagram of a device for measuring the synchronism of a motion mechanism.

Fig. 3 is a measurement expansion schematic diagram of a motion mechanism synchronism measurement device.

In the figure: 1. a laser emitter; 2. a reference shaft guide rail; 3. a first guide rail of the tested shaft; 4. a portal frame; 5. a pentaprism; 6. a PSD sensor; 7. and a second guide rail of the tested shaft.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings in the embodiments of the present invention.

Referring to fig. 1, a high-precision measuring device of a transmitting device comprises a laser transmitter 1, a pentaprism 5, a PSD sensor 6 and a data processing terminal; the laser transmitter 1 is fixed at one end of a reference shaft, and can adjust a laser beam to be parallel to the reference shaft, wherein the laser beam is a measured reference; the pentaprism 5 is arranged on a movable workbench or a movable portal frame, and the installation position is as close to a reference shaft as possible and is used for transmitting a reference standard (namely a laser beam); the PSD sensor 6 is arranged on the movable workbench or the movable portal frame, is positioned close to the detected shaft, and is used for receiving the laser beam and outputting data of the relative displacement variation.

Fig. 2-3 are schemes for measuring the synchronism of a gantry mobile machine tool, at this time, the gantry whole frame of the machine tool is assembled, two parallel guide rails are fixed on the guide rails through bottom upright posts, the gantry is moved on the guide rails through double-drive motors on two sides, and torsion phenomenon can occur due to the problems of the accuracy of the guide rails or the asynchronous motor driving, and the use requirements are not met.

In order to enable the gantry mobile machine tool to meet the use requirement, the bilateral synchronicity measurement of the gantry in the embodiment adopts the following steps:

s1, erecting a laser transmitter on a lathe bed or an external tripod at one end of a reference shaft, setting two measurement reference points at the moving proximal end and the moving distal end of the reference shaft, and adjusting an adjusting knob of the laser transmitter to enable data trend of a PSD sensor at the two reference points to be consistent, so that the laser beam is parallel to the reference shaft; after the step is completed, a reference datum for measurement is determined, and the laser transmitter needs to be kept stationary;

s2, installing a pentaprism at the position of the portal frame close to the reference shaft, so that the laser beam is deflected by 90 degrees and is emitted to the detected shaft; during measurement, the pentaprism moves along with the portal frame;

s3, installing the PSD sensor on a position, close to a detected shaft, on the portal frame, and adjusting the position of the PSD sensor to enable a laser beam to be incident to the center position of the PSD sensor; at the moment, the PSD sensor can measure the accurate position of the laser beam at the sensor and transmit data to the data processing terminal through wireless Bluetooth; zeroing the position data when measuring the first position;

s4, moving the portal frame or the workbench, and recording the generated position data.

S5, inputting the acquired data to a data processing end, and adjusting relevant parameters of a machine tool control system according to a calculation result to correct the synchronism error.

S6, repeating the steps S4-S5 until the measured synchronism error is smaller than a set threshold value.

In the scheme, the movement direction of the reference shaft is X1; the motion direction of the detected shaft is X2; the direction of the laser beam reflected by the pentaprism is Y; the Y direction is ensured to be vertical to the X1 direction through a pentaprism; the structure and principle of the pentaprism ensure that the perpendicularity between the outgoing laser beam and the incoming laser beam is hardly affected by the change of the incident angle of the laser beam caused by the change of the posture of the pentaprism; the small round reflecting mirror for indicating and adjusting the position and angle of the incident laser beam is designed in front of the incident surface of the pentaprism, so that the micro perpendicularity deviation caused by the surface shape error of the pentaprism is further reduced.

When the gantry structure generates torsion on the guide rails at two sides due to the asynchronism, the laser beams in the Y direction are refracted by the pentaprism on the reference shaft, and the position of the laser beams which are shot on the PSD sensor changes (relative to the initial measuring point or other reference measuring points); when the gantry or the workbench is twisted on the guide rail, the Y direction is still vertical to the detected shaft X2, but the detected shaft of the gantry or the workbench is deviated from the reference shaft in the front-back position in the moving direction, the deviation is the synchronism error of the two sides, the reading on the PSD sensor is delta X, and the reading delta X of the PSD sensor is the synchronism error of the measuring point.

When the number of the guide rails is greater than two, after one axis is selected as a reference axis, a penta prism and a PSD sensor measuring unit are added to finish multi-axis synchronism error measurement.

In summary, the synchronization measurement scheme of the gate-movable machine tool in the embodiment is suitable for most of equipment such as machine tools with movable tables, movable gantry or similar structures, and can realize long-distance and large-span guide rail synchronization measurement and error compensation, and has simple operation steps, and error data can be directly represented by position transformation of a PSD sensor.

Compared with the traditional method of beating the meter, the method has higher precision, simpler operation and easier operation than the double interferometer method, and simultaneously improves the precision by a certain amount; meanwhile, after the reference shaft is determined, the measurement scheme can realize the synchronous measurement of three or more guide rails by only adding a measurement unit.

Although the present invention has been described with reference to the foregoing embodiments, it will be apparent to those skilled in the art that modifications may be made to the embodiments described, or equivalents may be substituted for elements thereof, and any modifications, equivalents, improvements and changes may be made without departing from the spirit and principles of the present invention.

Claims

1. The motion mechanism synchronism measuring device comprises a laser transmitter, a pentaprism, a PSD sensor and a data processing terminal; the laser transmitter is fixed at one end of the reference shaft, and can adjust the laser beam to be parallel to the reference shaft, wherein the laser beam is a reference standard for measurement; the pentaprism is arranged on the movable workbench or the movable portal frame, and the installation position is as close to the reference shaft as possible and is used for transmitting the reference standard; the PSD sensor is arranged on the movable workbench or the movable portal frame, is close to the detected shaft and is used for receiving the laser beam and outputting data of the relative displacement variation.

2. The method for measuring the synchronism of a moving mechanism according to claim 1, characterized by comprising the steps of:

s1, erecting a laser emitter on a lathe bed or an external tripod at one end of a reference shaft, setting two measurement reference points at the moving proximal end and the moving distal end of the reference shaft, and adjusting an adjusting knob of the laser emitter to enable data trend of a PSD sensor at the two reference points to be consistent, so that the laser is parallel to the reference shaft; after the step is completed, a reference datum for measurement is determined, and the laser transmitter needs to be kept stationary;

s2, installing a pentaprism at a position of the workbench or the portal frame, which is close to the reference shaft, so that the laser beam is deflected by 90 degrees and is emitted to the tested shaft; during measurement, the pentaprism moves along with the workbench or the portal frame;

s3, installing the PSD sensor on a position, close to a detected shaft, on a workbench or a portal frame, and adjusting the position of the PSD sensor to enable a laser beam to be incident into the center position of the PSD sensor; at the moment, the PSD sensor can measure the accurate position of the laser beam at the sensor and transmit data to the data processing terminal through wireless Bluetooth; zeroing the position data when measuring the first position;

s4, moving the portal frame or the workbench, and recording the generated position data;

s5, inputting the acquired data to a data processing end, and adjusting relevant parameters of a motor control system for driving the workbench or the portal frame according to a calculation result to correct the synchronism error;

3. The measurement method of a movement mechanism synchronicity measurement device according to claim 2, wherein in the present embodiment the movement direction of the reference axis is X1; the motion direction of the detected shaft is X2; the direction of the laser beam reflected by the pentaprism is Y; the Y direction is ensured to be vertical to the X1 direction through a pentaprism; a small round reflecting mirror for indicating and adjusting the position and angle of the incident laser beam is designed in front of the incident surface of the pentaprism.

4. The measuring method of a movement mechanism synchronicity measuring apparatus according to claim 2, wherein when the gantry structure is twisted due to the asynchronism of the guide rails on both sides, the laser beam refracted to the Y direction by the pentaprism on the reference axis will change the position of the laser beam impinging on the PSD sensor; at this time, the reading Δx of the PSD sensor is the synchronicity error of the measurement point.

5. The method according to claim 2, wherein when the number of the guide rails is greater than two, the measurement of the multi-axis synchronism error is performed by adding a pentaprism and a PSD sensor measuring unit after selecting one axis as a reference axis.