A method and device for step-by-step measurement of precision displacement of a long-stroke workbench

Abstract

A method and device for step-by-step measurement of precision displacement of a long-stroke worktable relates to the field of precision measurement, and solves the technical problem that the long-range precision displacement measurement device in the prior art cannot precisely measure the moving working parts. The device includes: a measuring reflector, a double linear guide rail, a first measuring interference assembly, a second measuring interference assembly, a motor assembly, and a lead screw nut pair; the two ends of the lead screw in the lead screw nut pair are respectively arranged on the motor assembly and the first measuring interference assembly to maintain a fixed distance, the nut in the lead screw nut pair is installed on the second measuring interference assembly, the motor assembly drives the lead screw to rotate, the position of the second measuring interference assembly on the lead screw is changed, and the distance between the first measuring interference assembly and the second measuring interference assembly is adjusted; and the first measuring interference assembly, the second measuring interference assembly and the motor assembly are moved along the double linear guide rails; the first measuring interference assembly and the second measuring interference assembly respectively detect the object to be measured set on the measuring reflector.

Description

Technical Field

[0001] The invention relates to the field of precision measurement, and in particular to a method and device for step-by-step measurement of precision displacement of a long-stroke workbench. Background Art

[0002] Judging from the current research status and latest achievements at home and abroad, in the application of nanometer-level long-range precision displacement measurement, grating displacement measurement and difference frequency laser interferometer displacement measurement are widely used. However, long-range precision displacement measurement requires high grating line number and large length. Such grating is difficult to engrave, which is reflected in the contradiction between measurement resolution and range in length measurement. Moreover, the measurement accuracy is directly related to the manufacturing accuracy of the grating, and is greatly affected by the grating processing technology. Difference frequency laser interferometer measurement has the remarkable characteristics of high resolution, high precision, high speed, long stroke and multi-channel, and is the best choice for long-range precision displacement measurement. However, the disadvantage of laser interference displacement measurement instruments is that they have high requirements for environmental conditions. Environmental factors have a considerable impact on laser interferometer measurement systems. Under laboratory conditions, if relevant compensation for environmental factors is not performed, the error caused by them is at least ±2.68ppm, which cannot be ignored for long-range precision displacement measurement. At present, many products at home and abroad use temperature, air pressure, and humidity sensors to measure the corresponding parameters, use the Edlen formula to calculate the refractive index and wavelength values, and then input them into the signal processing system in parallel with the interferometer measurement signal to achieve air refractive index compensation. The measurement accuracy of this compensation method can reach ±0.03ppm. However, due to the limitations of measuring instruments and methods, it is impossible to accurately detect the environmental parameters of the entire displacement area for long-range precision displacement measurements, especially the precision measurement of moving working parts, and it is impossible to achieve accurate compensation for the environment. Summary of the invention

[0003] In order to solve the problems existing in the prior art, the present invention provides a method and device for step-by-step measurement of the precision displacement of a long-stroke workbench, which solves the technical problem that the long-range precision displacement measuring device in the prior art cannot accurately measure the moving working parts.

[0004] The technical solution adopted by the present invention to solve the technical problem is as follows:

[0005] A long-stroke workbench precision displacement step-by-step measurement device, the device comprises: a measuring reflector, a double linear guide rail, a first measuring interference component, a second measuring interference component, a motor component and a screw-nut pair; the two ends of the screw in the screw-nut pair are respectively arranged on the motor component and the first measuring interference component to maintain a fixed distance, the nut in the screw-nut pair is installed on the second measuring interference component, the motor component drives the screw to rotate, changes the position of the second measuring interference component on the screw, and adjusts the distance between the first measuring interference component and the second measuring interference component; and makes the first measuring interference component, the second measuring interference component and the motor component move along the double linear guide rails; the first measuring interference component and the second measuring interference component respectively detect the object to be measured set on the measuring reflector.

[0006] Preferably, the measuring reflector is fixed together with the object to be measured; the measuring reflector, the first measuring interference assembly, the second measuring interference assembly and the motor assembly are respectively arranged on the double linear guide rails, and reciprocate along the double linear guide rails; one end of the screw in the screw-nut pair is connected to the motor assembly; the other end is connected to the first measuring interference assembly; the nut in the screw-nut pair is installed on the second measuring interference assembly.

[0007] Preferably, the first measuring interference assembly includes: a first bracket, two measuring interferometers, a first slider group and a first clamp; the two measuring interferometers, the first slider group and the first clamp are arranged on the first bracket; the two measuring interferometers collect information of the object to be measured, the first slider group enables the first bracket to move on the dual linear guide rails, and the first clamp fixes the first bracket to limit the relative displacement of the first bracket and the dual linear guide rails.

[0008] Preferably, the second measuring interference assembly includes: a second bracket, a measuring interferometer, a second slider group and a second clamp; the measuring interferometer, the second slider group and the second clamp are arranged on the second bracket; the measuring interferometer collects information of the object to be measured, the second slider group enables the second bracket to move on the double linear guide rails, and the second clamp fixes the second bracket to limit the relative displacement of the second bracket and the double linear guide rails; the second bracket is fixed on the nut and reciprocates along the lead screw.

[0009] Preferably, the motor assembly comprises: a motor, a motor bracket and a third slider group; the motor and the third slider group are arranged on the motor bracket, and the third slider group enables the motor bracket to move on the double linear guide rails.

[0010] Preferably, it also includes: a coupling; the lead screw is connected to the motor via the coupling.

[0011] A measuring method for a long-stroke workbench precision displacement step-by-step measuring device, the method comprising the following steps:

[0012] Step 1: In the initial stage of measurement, the second measuring interferometer assembly is placed close to the first measuring interferometer assembly, the first clamp and the second clamp are locked, the first measuring interferometer assembly, the second measuring interferometer assembly and the double linear guide rail are relatively stationary, and the object to be measured is close to the first measuring interferometer assembly; at this time, the measurement value of the first measuring interferometer assembly is the same as the measurement value of the second measuring interferometer assembly, which is set as the starting measurement value;

[0013] Step 2: The object to be measured is away from the first measuring interferometer component and the second measuring interferometer component, and the measurement value of the first measuring interferometer component and the measurement value of the second measuring interferometer component are set as the first stage measurement value;

[0014] Step three: the object to be measured is stationary, the second clamp is locked, the first clamp is released, the motor is started in the forward direction to drive the screw to rotate, the second measuring interferometer assembly and the dual linear guide rails are relatively stationary, the motor and the first measuring interferometer assembly are relatively stationary, and they move synchronously toward the object to be measured; when the first measuring interferometer assembly moves close to the object to be measured, the motor is turned off, the first clamp and the second clamp are locked, the first measuring interferometer assembly, the second measuring interferometer assembly and the dual linear guide rails are relatively stationary, and the measurement value of the second measuring interferometer assembly covers the measurement value of the first measuring interferometer assembly. At this time, the measurement value of the first measuring interferometer assembly is the same as the measurement value of the second measuring interferometer assembly, which is still the measurement value of the first stage.

[0015] Step 4: The first clamp is locked, the second clamp is released, and the motor is started in reverse to drive the screw to rotate. The motor, the first measuring interferometer assembly and the double linear guide rails are relatively stationary, and the second measuring interferometer assembly moves toward the object to be measured; when the second measuring interferometer assembly moves close to the first measuring interferometer assembly, the motor is turned off, the first clamp and the second clamp are locked, the first measuring interferometer assembly, the second measuring interferometer assembly and the double linear guide rails are relatively stationary, and the measurement value of the first measuring interferometer assembly covers the measurement value of the second measuring interferometer assembly. At this time, the measurement value of the first measuring interferometer assembly is the same as the measurement value of the second measuring interferometer assembly, which is still the measurement value of the first stage; at this time, the second measuring interferometer assembly is close to the first measuring interferometer assembly, and the object to be measured is close to the first measuring interferometer assembly;

[0016] Step 5: Repeat step 2 and obtain the second stage measurement value;

[0017] Step 6: Repeat step 3-step 5-step 2-step 3-step 5-… until the workbench runs the entire stroke, add up the measurement values ​​of all stages, and realize a measurement method for a long-stroke workbench precision displacement step-by-step measurement device.

[0018] Beneficial effects of the present invention: The present invention realizes precise displacement measurement of a long-stroke workbench by means of step-by-step measurement and data transmission, thereby avoiding the problem that large-range laser measurement is affected by environmental disturbances. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 A schematic structural diagram of a device for measuring the precise displacement of a long-stroke workbench according to the present invention.

[0020] Figure 2 A bottom view of a device for measuring the precision displacement of a long-stroke workbench in steps according to the present invention.

[0021] Figure 3 A flow chart of a method for step-by-step measurement of precise displacement of a long-stroke workbench according to the present invention.

[0022] In the figure: 1. measuring reflector, 2. first measuring interference component, 21. first slider group, 22. first clamp, 23. first bracket, 3. second measuring interference component, 31. second slider group, 32. second clamp, 33. second bracket, 4. motor, 41. third slider group, 42. coupling, 43. motor bracket, 5. lead screw, 51. lead screw supporting end, 52. nut, 53. lead screw fixed end, 6. double linear guide rails. DETAILED DESCRIPTION

[0023] The present invention is further described in detail below with reference to the accompanying drawings and embodiments.

[0024] like Figure 1 and Figure 2 As shown, a long-stroke workbench precision displacement step-by-step measurement device comprises: a measuring reflector 1, a first measuring interference assembly 2, a second measuring interference assembly 3, a motor assembly, a coupling 42, a screw nut pair and a double linear guide 6. The two ends of the screw 5 in the screw nut pair are respectively arranged on the motor assembly and the first measuring interference assembly 2 to maintain a fixed distance, and the nut 52 in the screw nut pair is installed on the second measuring interference assembly 3. The motor assembly drives the rotation of the screw 5 through the coupling 42, changes the position of the second measuring interference assembly 3 on the screw 5, adjusts the distance between the first measuring interference assembly 2 and the second measuring interference assembly 3; and makes the first measuring interference assembly 2, the second measuring interference assembly 3 and the motor assembly move along the double linear guide 6; the first measuring interference assembly 2 and the second measuring interference assembly 3 respectively detect the object to be measured set on the measuring reflector 1.

[0025] Among them, the measuring reflector 1 is fixed together with the object to be measured; the measuring reflector 1, the first measuring interference component 2, the second measuring interference component 3 and the motor component are respectively arranged on the double linear guide rails 6, and reciprocate along the double linear guide rails 6; one end of the screw 5 in the screw-nut pair is connected to the motor assembly, called the screw fixing end 53; the other end is connected to the first measuring interference component, called the screw supporting end 51; the nut 52 in the screw-nut pair is installed on the second measuring interference component 3.

[0026] The first measuring interference assembly 2 includes: a first bracket 23, two measuring interferometers, a first slider group 21 and a first clamp 22; the two measuring interferometers, the first slider group 21 and the first clamp 22 are arranged on the first bracket 23; the two measuring interferometers collect information about the object to be measured, the first slider group 21 enables the first bracket 23 to move on the double linear guide 6, and the first clamp 22 fixes the first bracket 23 to limit the relative displacement between the first bracket 23 and the double linear guide 6. The second measuring interference assembly 3 includes: a second bracket 33, a measuring interferometer, a second slider group 31 and a second clamp 32; the measuring interferometer, the second slider group 31 and the second clamp 32 are arranged on the second bracket 33; the measuring interferometer collects information about the object to be measured, the second slider group 31 enables the second bracket 33 to move on the double linear guide 6, and the second clamp 32 fixes the second bracket 33 to limit the relative displacement between the second bracket 33 and the double linear guide 6; the second bracket 33 is fixed on the nut 52 and reciprocates along the lead screw 5. The motor assembly includes: a motor 4 , a motor bracket 43 and a third slider group 41 ; the motor 4 and the third slider group 41 are arranged on the motor bracket 43 , and the third slider group 41 enables the motor bracket 43 to move on the double linear guide rails 6 .

[0027] A measuring method for a long-stroke workbench precision displacement step-by-step measuring device, the method comprising the following steps:

[0028] Step 1: If Figure 3 -(a), in the initial stage of measurement, the second measuring interferometer assembly 3 is placed close to the first measuring interferometer assembly 2, the first clamp 22 is locked, the second clamp 32 is locked, the first measuring interferometer assembly 2, the second measuring interferometer assembly 3 and the double linear guide rail 6 are relatively still, and the measuring reflector 1 fixed to the object to be measured is close to the first measuring interferometer assembly 2. At this time, the measurement value of the first measuring interferometer assembly 2 is the same as the measurement value of the second measuring interferometer assembly 3, which is the starting measurement value.

[0029] Step 2: If Figure 3-(b), the measuring reflector 1 fixed to the measured object moves away from the first measuring interferometer component 2 and the second measuring interferometer component 3 as the workbench moves. At this time, the measurement values ​​of the first measuring interferometer component 2 and the second measuring interferometer component 3 both change, and the change amounts are the same. Since the movement of the workbench is small and the environmental interference is small, the measurement values ​​of the first measuring interferometer component 2 and the second measuring interferometer component 3 are both regarded as credible values, which are the first stage measurement values.

[0030] Step 3: If Figure 3 -(c), the workbench stops moving, the measuring reflector 1 is stationary, the second clamp 32 is locked, the first clamp 22 is released, the motor 4 is started in the forward direction, the screw 5 is driven to rotate through the coupling 42, the second measuring interferometer assembly 3 and the double linear guide 6 are relatively stationary, the motor 4 and the first measuring interferometer assembly 2 are relatively stationary, and move synchronously toward the measuring reflector 1. At this time, the measurement value of the second measuring interferometer assembly 3 is regarded as a credible value, the first measuring interferometer assembly 2 has moved relative to the double linear guide 6, and the measurement value is unreliable. When the first measuring interferometer assembly 2 is close to the measuring reflector 1, the motor 4 is turned off, the first clamp 22 is locked, the second clamp 32 is locked, the first measuring interferometer assembly 2, the second measuring interferometer assembly 3 and the double linear guide 6 are relatively stationary, the measurement value of the second measuring interferometer assembly 3 covers the measurement value of the first measuring interferometer assembly 2, and the measurement value of the first measuring interferometer assembly 2 and the measurement value of the second measuring interferometer assembly 3 are both regarded as credible values, which are still the first stage measurement values.

[0031] Step 4: If Figure 3 -(d), the first clamp 22 is locked, the second clamp 22 is released, the motor 4 is started in reverse, the lead screw 5 is driven to rotate through the coupling 42, the drive motor 4, the first measuring interferometer assembly 2 and the double linear guide 6 are relatively stationary, and the second measuring interferometer assembly 3 moves toward the measuring reflector 1. At this time, the measurement value of the first measuring interferometer assembly 2 is regarded as a credible value, the second measuring interferometer assembly 3 has moved relative to the double linear guide 6, and the measurement value is unreliable. When the second measuring interferometer assembly 3 moves close to the measuring reflector 1, the motor 4 is turned off, the first clamp 22 is locked, the second clamp 32 is locked, the first measuring interferometer assembly 2, the second measuring interferometer assembly 3 and the double linear guide 6 are relatively stationary, the measurement value of the first measuring interferometer assembly 2 covers the measurement value of the second measuring interferometer assembly 3, the measurement value of the first measuring interferometer assembly 2 and the measurement value of the second measuring interferometer assembly 3 are both regarded as credible values, and are still the first stage measurement values. At this time, the second measuring interferometer component 3 is close to the first measuring interferometer component 2, and the measuring reflector 1 fixed together with the measured object is close to the first measuring interferometer component 2. Figure 3 -(a) shows the same state,

[0032] Step 5: If Figure 3 -(e), repeat the process shown in step 2 and obtain the second stage measurement value.

[0033] Repeat step 3 - step 5 - step 2 - step 3 - step 5 - ... repeatedly until the workbench runs the entire stroke.

Claims

1. A method for measuring the precision displacement of a long-stroke workbench in steps, characterized in that: The method is based on a long-stroke workbench precision displacement step-by-step measurement device, which includes: a measuring reflector, a double linear guide rail, a first measuring interference component, a second measuring interference component, a motor component and a lead screw nut pair; the two ends of the lead screw in the lead screw nut pair are respectively arranged on the motor component and the first measuring interference component to maintain a fixed distance, the nut in the lead screw nut pair is installed on the second measuring interference component, the motor component drives the lead screw to rotate, the position of the second measuring interference component on the lead screw is changed, and the distance between the first measuring interference component and the second measuring interference component is adjusted; and the first measuring interference component, the second measuring interference component and the motor component are moved along the double linear guide rails; the first measuring interference component and the second measuring interference component respectively detect the object to be measured set on the measuring reflector; The method comprises the following steps: Step 1: In the initial stage of measurement, the second measuring interference assembly is placed close to the first measuring interference assembly, the first clamp and the second clamp are locked, and the first measuring interference assembly, the second measuring interference assembly and the double linear guide rail are relatively stationary; the object to be measured is placed close to the first measuring interference assembly; at this time, the measurement value of the first measuring interference assembly is the same as the measurement value of the second measuring interference assembly, which is set as the starting measurement value; Step 2: The object to be measured is away from the first measuring interferometer component and the second measuring interferometer component, and the measurement value of the first measuring interferometer component and the measurement value of the second measuring interferometer component are set as the first stage measurement value; Step 3: the object to be measured is stationary, the second clamp is locked, the first clamp is released, the motor is started in the forward direction, the lead screw is driven to rotate, the second measuring interference component and the double linear guide rails are relatively stationary, the motor and the first measuring interference component are relatively stationary, and they move toward the object to be measured synchronously; when the first measuring interference component moves close to the object to be measured, the motor is turned off, the first clamp and the second clamp are locked, the first measuring interference component, the second measuring interference component and the double linear guide rails are relatively stationary, and the measurement value of the second measuring interference component covers the measurement value of the first measuring interference component. At this time, the measurement value of the first measuring interference component is the same as the measurement value of the second measuring interference component, which is still the measurement value of the first stage; Step 4: The first clamp is locked, the second clamp is released, the motor is started in reverse, the lead screw is driven to rotate, the motor, the first measuring interference component and the double linear guide rails are relatively stationary, and the second measuring interference component moves toward the direction of the object to be measured; when the second measuring interference component moves close to the first measuring interference component, the motor is turned off, the first clamp and the second clamp are locked, the first measuring interference component, the second measuring interference component and the double linear guide rails are relatively stationary, and the measurement value of the first measuring interference component covers the measurement value of the second measuring interference component. At this time, the measurement value of the first measuring interference component is the same as the measurement value of the second measuring interference component, which is still the measurement value of the first stage; at this time, the second measuring interference component is close to the first measuring interference component, and the object to be measured is close to the first measuring interference component; Step 5: Repeat step 2 and obtain the second stage measurement value; Step 6: Repeat the cycle of step 3-step 5-step 2 until the workbench runs the entire stroke, add up the measurement values ​​of all stages, and realize a measurement method for a long-stroke workbench precision displacement step-by-step measurement device.

2. The method for measuring the precision displacement of a long-stroke worktable according to claim 1, characterized in that: The measuring reflector is fixed to the object to be measured; the measuring reflector, the first measuring interference assembly, the second measuring interference assembly and the motor assembly are respectively arranged on the double linear guide rails and reciprocate along the double linear guide rails; one end of the lead screw in the lead screw and nut pair is connected to the motor assembly; the other end is connected to the first measuring interference assembly; the nut in the lead screw and nut pair is installed on the second measuring interference assembly.

3. The method for measuring the precision displacement of a long-stroke worktable according to claim 1, characterized in that: The first measuring interference assembly includes: a first bracket, two measuring interferences, a first slider group and a first clamp; the two measuring interferences, the first slider group and the first clamp are arranged on the first bracket; the two measuring interferences collect information of the object to be measured, the first slider group enables the first bracket to move on the double linear guide rails, and the first clamp fixes the first bracket to limit the relative displacement of the first bracket and the double linear guide rails.

4. The method for measuring the precision displacement of a long-stroke worktable in steps according to claim 1, characterized in that: The second measurement interference assembly includes: a second bracket, a measurement interference, a second slider group and a second clamp; the measurement interference, the second slider group and the second clamp are arranged on the second bracket; the measurement interference collects information of the object to be measured, the second slider group enables the second bracket to move on the double linear guide rails, and the second clamp fixes the second bracket to limit the relative displacement of the second bracket and the double linear guide rails; the second bracket is fixed on the nut and reciprocates along the lead screw.

5. The method for measuring the precision displacement of a long-stroke worktable in steps according to claim 1, characterized in that: The motor assembly comprises: a motor, a motor bracket and a third slider group; the motor and the third slider group are arranged on the motor bracket, and the third slider group enables the motor bracket to move on the double linear guide rails.

6. The method for measuring the precision displacement of a long-stroke worktable in steps according to claim 1, characterized in that: Also includes: Coupling; the lead screw is connected to the motor through the coupling.

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