Multi-axis turntable calibration device, system and method

Abstract

The invention discloses a multi-axis turntable calibration device, system and method, aiming at a turntable without an angular pulse signal output interface, the device can solve the problem that the angular rate of the turntable cannot be calibrated. The problem that the credibility is not high due to the fact that the angle reference is not measured when a frequency meter is used for calibrating the angular rate of the rotary table is solved. The device solves the problem that some large-scale multi-axis rotary tables cannot be calibrated by using a timing angle measurement method due to the installation limiting problem. According to the device, the angular position error and angular rate error calibration of the turntable can be completed through one set of equipment, and the inconvenience caused by too many tools carried by the turntable as field calibration equipment is solved.

Description

Technical Field

[0001] The invention relates to a multi-axis turntable calibration device, system and method, and belongs to the field of geometric quantity and mechanical metrology calibration. Background Art

[0002] According to the relevant requirements for turntable calibration in "JJF1210-2008 Low-speed Turntable Calibration Specification" and "JJF1669-2008 Three-axis Turntable Calibration Specification", it is mainly necessary to calibrate the angular position and angular velocity parameters of the turntable. Usually, two different sets of devices need to be prepared to calibrate the angular position and angular velocity respectively. When calibrating the angular position, a regular polyhedron is generally used in conjunction with a photoelectric autocollimator. However, the photoelectric autocollimator is usually large in size, and the turntable is mostly a field calibration device, which is inconvenient to carry. When calibrating the angular velocity of the turntable, a digital frequency meter is generally used as the time reference, and the angular position output by the turntable's own angular position measurement system is used as the angle reference to obtain the angular velocity. This method is equivalent to assuming that the turntable's own angle reference value is accurate, but in the actual process, the angle reference is not measured when measuring the angular velocity, so the accuracy of the obtained calibration result is questionable. And due to the limitations of most turntables at the beginning of their design, some older turntables did not have a reserved port for angular rate pulses at the beginning of their design or could only use 360° fixed angle pulses, making it impossible to use a frequency meter to measure angular rate or taking a very long time to measure rate points below 10° / s. Therefore, it is urgent to provide a new technical solution to effectively solve the above problems. Summary of the invention

[0003] The present invention aims to provide a multi-axis turntable calibration device, system and method, which can solve the problem that the angular velocity calibration cannot be performed for a turntable without an angular pulse signal output interface, and the problem that when a frequency meter is used to calibrate the angular velocity of the turntable, its angle reference is not measured, resulting in low reliability. The device can complete the calibration of the angular position error and angular velocity error of the turntable with a set of equipment, thereby solving the inconvenience caused by carrying too many instruments when the turntable is used as an on-site calibration device.

[0004] In order to achieve the above-mentioned purpose, the technical solution adopted by the present invention is: a multi-axis turntable calibration device, the device includes a magnetic base, a mounting core shaft, a circular grating mounting disk, and a mounting bolt; the magnetic base is installed at the center of the rotating shaft of the multi-axis turntable, and the mounting core shaft is rigidly connected to the magnetic base; the interior of the mounting core shaft is embedded with a screw hole, and the center of the circular grating mounting disk is provided with a through hole, the threaded rod of the mounting bolt passes through the through hole and is threadedly connected to the screw hole of the mounting core shaft, so that the circular grating mounting disk is fixedly installed to the upper end of the mounting core shaft.

[0005] The multi-axis turntable calibration device provided by the present invention can meet the calibration requirements of most turntables. In actual use, the device only needs to be assembled and installed at the center of the rotating shaft of the turntable to complete the installation, which is convenient and fast, and saves the calibration time of the turntable. The device is installed at the center of the rotating shaft of the turntable through the magnetic base, avoiding the traditional installation method that can only be installed inside the rotating shaft, thereby causing problems such as data cable entanglement or interference between the outer frame and the reading head bracket.

[0006] According to the embodiments of the present invention, the present invention can be further optimized. The following is the technical solution formed after optimization: In one preferred embodiment, there are four mounting bolts to facilitate the adjustment of the parallelism and verticality of the device when calibrating the angular position of the turntable.

[0007] In one of the preferred embodiments, the cross-section of the mounting bolt is circular. That is, the circular grating mounting disk and the mounting bolt are matched with a cylindrical surface, so that the device can be installed horizontally or inverted, solving the problem that the outer frame or middle frame of some large three-axis turntables and two-axis turntables cannot be calibrated using the timing angle measurement method due to installation limitations. The timing angle measurement method uses an angle encoder to measure the time the turntable moves within a certain angle, thereby calculating its angular velocity. The angle encoder of the timing angle measurement method is easy to trace and has a high degree of credibility.

[0008] In one preferred embodiment, the screw diameter of the mounting bolt is not less than 17 mm. The mounting bolt is a large screw structure, and the circular grating mounting plate is fixed to the upper end of the mounting mandrel by the mounting bolt, which is convenient for horizontal or inverted installation of the entire device on the outer frame or middle frame of some large turntables during angular velocity calibration.

[0009] In one preferred embodiment, the head of the mounting bolt is a knob structure, which makes it easy to tighten the bolt by hand, reduces the use of tools, improves the convenience of the whole device, saves turntable calibration time, and improves efficiency.

[0010] Based on the same concept, the present invention also provides a multi-axis turntable calibration system, the system comprising the multi-axis turntable calibration device as described above, and also comprising a circular grating (5), a circular grating reading head (6), and a computer (7); the circular grating (5) is fixed to the circular grating mounting plate (3), the circular grating reading head (6) is fixed to the circular grating (5) by a bracket and aligned with the circular grating, and the circular grating reading head (6) is connected to the computer (7).

[0011] The circular grating is fixedly mounted on the circular grating mounting plate. When stored, the circular grating and the circular grating mounting plate can be placed together in a rust-proof protection box, which is convenient to carry and avoids repeated disassembly and assembly of the circular grating to affect its accuracy.

[0012] In one preferred embodiment, the circular grating is rigidly connected to the circular grating mounting plate by screws, so as to prevent the circular grating from accidentally falling off during inverted installation.

[0013] In one preferred embodiment, the circular grating mounting plate is replaced with a regular polyhedron. When the turntable angular position accuracy requirement is high and the circular grating accuracy is limited and may not meet the requirement, the circular grating mounting plate of the device can be replaced with a regular polyhedron and used in conjunction with a photoelectric autocollimator to achieve high-precision angular position measurement.

[0014] In one of the preferred embodiments, the bracket can be fixed to the ground, or the bracket can be fixed to a non-moving part of the multi-axis turntable.

[0015] Based on the same concept, the present invention also provides a multi-axis turntable calibration method, which is based on the multi-axis turntable calibration device described above and includes an angular velocity calibration mode and an angular position calibration mode: The multi-axis turntable calibration device is installed to the center of the rotating shaft, the magnetic switch is turned on, the multi-axis turntable is started, and calibration begins; Angular rate calibration mode: the calibration points of the multi-axis turntable are set according to the calibration specification, the multi-axis turntable calibration device rotates with the multi-axis turntable, and the circular grating reading head feeds back the data required for angular rate calibration to the portable computer for processing to obtain the real-time angular rate calibration parameters of the turntable; Angular position calibration mode: the calibration points of the multi-axis turntable are set according to the calibration specifications, the multi-axis turntable calibration device rotates with the multi-axis turntable, and the circular grating reading head feeds back the data required for angular position calibration to the portable computer for processing to obtain the real-time angular position calibration parameters of the turntable.

[0016] Compared with the prior art, the beneficial effects of the present invention are as follows: the multi-axis turntable calibration device, system and method provided by the present invention can solve the problem that the angular velocity calibration cannot be performed for a turntable without an angular pulse signal output interface; and solve the problem that when a frequency meter is used to calibrate the angular velocity of a turntable, its angle reference is not measured, resulting in low reliability. The device solves the problem that some large multi-axis turntables cannot be calibrated using the timed angle measurement method due to installation limit issues. The device can complete the calibration of the angular position error and angular velocity error of the turntable through a set of equipment, solving the inconvenience caused by carrying too many instruments when the turntable is used as an on-site calibration device. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 is an assembly diagram of a multi-axis turntable calibration device according to an embodiment of the present invention during calibration; Figure 2 is a front view of a mounting mandrel according to an embodiment of the present invention; Figure 3 is a front view of a circular grating mounting plate according to an embodiment of the present invention; Figure 4 is a front view of a mounting bolt according to another embodiment of the present invention; FIG5 is a schematic diagram of horizontal installation and inverted installation of a multi-axis turntable calibration device according to another embodiment of the present invention; FIG5(a) is a schematic diagram of horizontal installation of the multi-axis turntable calibration device, and FIG5(b) is a schematic diagram of inverted installation of the multi-axis turntable calibration device.

[0018] Among them, 1 is a magnetic base, 2 is a mounting core shaft, 3 is a circular grating mounting plate, 4 is a mounting bolt, 5 is a circular grating, 6 is a circular grating reading head, 7 is a computer, 8 is a multi-axis turntable calibration device, 9 is a turntable middle frame, and 10 is a turntable outer frame. DETAILED DESCRIPTION

[0019] The present invention will be described in detail below with reference to the accompanying drawings and in combination with embodiments. It should be noted that the embodiments and features in the embodiments of the present invention can be combined with each other without conflict.

[0020] Example 1 This embodiment 1 provides a multi-axis turntable calibration device, which is compact and convenient, quick to install, simple to use, and ensures calibration accuracy. Figure 1 As shown, the device includes a magnetic base 1, a mounting mandrel 2, a circular grating mounting plate 3, and a mounting bolt 4. The magnetic base 1 is mounted on a turntable of a speed to be detected, and the mounting mandrel 2 is rigidly connected to the magnetic base 1, as shown in FIG. Figure 2 As shown, it is a front view of the installation mandrel 2. The high-precision circular grating 5 is installed on the circular grating installation plate 3 and is installed together with the upper end of the installation mandrel 2, fixed by the mounting bolts 4, and the circular grating reading head 6 is fixed by a bracket and connected to the computer 7. According to the "JJF1210-2008 Low-speed Turntable Calibration Specification" and "JJF1669-2008 Three-axis Turntable Calibration Specification", the angular position and angular velocity calibration parameters of the turntable are calculated by a computer program. Figure 3 The figure shows the front view of the circular grating mounting plate 3.

[0021] There are four mounting bolts 4 to facilitate the adjustment of the parallelism and verticality of the device when calibrating the angular position of the turntable. The circular grating 5 and the circular grating reading head 6 are selected from high-precision grating disks and reading heads to ensure measurement accuracy. The mounting bolts 4 are large screw structures to facilitate the horizontal or inverted installation of the entire device on the outer frame or middle frame of some large turntables when calibrating the angular rate.

[0022] In view of the shortcomings of the existing turntable calibration test, the multi-axis turntable calibration device provided in this embodiment 1 meets the calibration requirements of most turntables. In actual use, it is only necessary to assemble the device and install it to the center of the turntable shaft to complete the installation, which is convenient and quick. In view of the problem that the outer frame or middle frame of some large three-axis turntables and dual-axis turntables are difficult to calibrate, the entire device can be installed horizontally or inverted, and installed at the center of the turntable shaft through the magnetic base 1, avoiding the traditional installation method that can only be installed inside the shaft, resulting in data cable entanglement or interference between the outer frame and the reading head bracket. The mounting bolt 4 is a large screw structure, and the circular grating mounting plate 3 is fixed to the upper end of the mounting core shaft 2 through the mounting bolt 4, which is convenient for the horizontal or inverted installation of the entire device on the outer frame or middle frame of some large turntables when the angular velocity is calibrated. At the same time, the bolt head is a knob structure, and the bolt can be tightened by hand without the help of extra tools, which is easy to operate. The circular grating 5 is installed on the circular grating installation disk 3. When storing, the entire installation disk device can be placed in a rust-proof protection box, which is convenient for protection and carrying, and avoids repeated disassembly and assembly of the circular grating 5 to affect its accuracy.

[0023] Example 2 The multi-axis turntable calibration system provided in this embodiment 2 includes a multi-axis turntable calibration device 8, a circular grating 5, a circular grating reading head 6, and a portable computer. The multi-axis turntable calibration device 8 includes a magnetic base 1, a mounting core shaft 2, a circular grating mounting disk 3, and a mounting bolt 4. The magnetic base 1 is installed at the center of the rotating shaft of the turntable to be inspected, the mounting core shaft 2 is rigidly connected to the magnetic base 1, the circular grating mounting disk 3 is installed on the upper end of the mounting core shaft 2 and fixed with the mounting bolt 4, the circular grating 5 is fixed to the circular grating mounting disk 3, the circular grating reading head 6 is fixed with a bracket to align with the circular grating 5, and is connected to the portable computer, and the angular position and angular velocity calibration parameters of the turntable are calculated by a computer program.

[0024] The mounting core shaft 2 is rigidly connected to the magnetic chassis 1 .

[0025] The installation mandrel 2 is embedded with a screw hole, the center of the circular grating installation plate 3 is provided with a through hole, the threaded rod of the installation bolt 4 passes through the through hole and is connected to the screw hole of the installation mandrel 2 by threading, so that the circular grating installation plate 3 is fixedly installed to the upper end of the installation mandrel 2; The circular grating mounting disk 3 and the mounting bolt 4 are cylindrically matched. In order to facilitate the horizontal and inverted installation of the entire device on the outer frame or middle frame of some large turntables during angular velocity calibration. As shown in FIG5 , FIG5( a ) is a schematic diagram of the horizontal installation of the multi-axis turntable calibration device 8, and FIG5( b ) is a schematic diagram of the inverted installation of the multi-axis turntable calibration device 8.

[0026] The head of the mounting bolt 4 is a knob structure, and the bolt can be tightened by hand, which reduces the use of tools, improves the convenience of the entire device, saves turntable calibration time, and improves efficiency. Figure 4 shown.

[0027] The circular grating 5 is mounted on the circular grating mounting disk 3 and is rigidly connected using screws.

[0028] The circular grating reading head 6 is used in conjunction with a corresponding bracket, and the bracket can be fixed on the ground or on a non-moving part of the turntable to be inspected, and the installation method is flexible and reliable.

[0029] The circular grating 5 and circular grating reading head 6 are made of high-precision grating disk and reading head to ensure measurement accuracy.

[0030] According to "JJF1210-2008 Low-speed Turntable Calibration Specification" and "JJF1669-2008 Three-axis Turntable Calibration Specification", the portable computer 7 is installed with the data reading and processing program of the circular grating reading head 6, which can directly obtain the turntable calibration data, which is convenient and efficient.

[0031] This embodiment 2 also provides a multi-axis turntable calibration method, using the device to calibrate the angular position error and angular velocity error of the turntable, and the specific steps include: In actual use, the device can be assembled in advance and directly installed to the center of the turntable shaft during calibration. The magnetic switch is turned on, and calibration can be started directly after the device is stable, which greatly saves the turntable calibration time.

[0032] After the device is installed, start the turntable to be inspected, set the turntable calibration points according to the relevant requirements of "JJF1210-2008 Low-speed Turntable Calibration Specification" and "JJF1669-2008 Three-axis Turntable Calibration Specification", the magnetic base 1, the installation spindle 2, the circular grating installation plate 3, the installation bolts 4, and the circular grating 5 rotate simultaneously with the rotation of the turntable, and the circular grating reading head 6 is stationary, and the data is fed back to the portable computer 7 for processing through the reading head to obtain the turntable calibration data in real time. The error between the obtained data and the turntable setting value is calculated to determine whether the turntable value is qualified or not.

[0033] When the turntable angular position accuracy requirement is high and the circular grating 5 itself is limited in accuracy and cannot meet the requirement, the circular grating mounting plate 3 can be replaced with a regular polyhedron and used in conjunction with a photoelectric autocollimator to achieve high-precision angular position measurement.

[0034] Compared with the existing turntable calibration device, the device provided in this embodiment 2 solves the problem that the outer frame or inner frame of some large multi-axis turntables cannot be calibrated for angular velocity due to installation problems. The device solves the problem that some turntables do not have a reserved port for angular velocity pulses or can only use 360° fixed angle pulses, and cannot use frequency meters for angular velocity measurement or are inefficient when measuring rate points below 10° / s. The angle reference is traceable, and the calibration results are more reliable and more convincing. The device is easy to install and flexible and reliable to use. The length, width and height of the whole device do not exceed 200mm*200mm*100mm, which is easy to carry. The angular position error and angular velocity error calibration of the turntable are completed through one set of equipment, solving the inconvenience caused by carrying too many instruments as the turntable as an on-site calibration device.

[0035] The contents explained in the above embodiments should be understood as these embodiments are only used to more clearly illustrate the present invention, and are not used to limit the scope of the present invention. After reading the present invention, various equivalent forms of modifications to the embodiments made by those skilled in the art fall within the scope defined by the claims attached to the present invention.

Claims

1. A multi-axis turntable calibration device, characterized in that: The device comprises a magnetic base (1), a mounting spindle (2), a circular grating mounting plate (3), and mounting bolts (4); The magnetic base (1) is mounted at the center of the rotating shaft of the multi-axis turntable, and the mounting spindle (2) is rigidly connected to the magnetic base (1); a screw hole is embedded in the interior of the mounting spindle (2), and a through hole is provided in the center of the circular grating mounting plate (3); a threaded rod of the mounting bolt (4) passes through the through hole and is threadedly connected to the screw hole of the mounting spindle (2), thereby fixing the circular grating mounting plate (3) to the upper end of the mounting spindle (2).

2. The multi-axis turntable calibration device according to claim 1, characterized in that: There are four mounting bolts (4).

3. The multi-axis turntable calibration device according to claim 1, characterized in that: The cross section of the mounting bolt (4) is circular.

4. The multi-axis turntable calibration device according to claim 3, characterized in that: The screw diameter of the mounting bolt (4) is not less than 17 mm.

5. The multi-axis turntable calibration device according to claim 3, characterized in that: The head of the mounting bolt (4) is a knob structure.

6. A multi-axis turntable calibration system, characterized in that: The system comprises the multi-axis turntable calibration device as described in claims 1 to 4, and also comprises a circular grating (5), a circular grating reading head (6), and a computer (7); the circular grating (5) is fixed to the circular grating mounting plate (3), the circular grating reading head (6) is fixed to the circular grating (5) by a bracket and aligned with the circular grating (5), and the circular grating reading head (6) is connected to the computer (7).

7. The multi-axis turntable calibration device according to claim 6, characterized in that: The circular grating (5) is rigidly connected to the circular grating mounting plate (3) via screws.

8. The multi-axis turntable calibration device according to claim 6, characterized in that: The circular grating mounting plate (3) is replaced with a regular polyhedron.

9. The multi-axis turntable calibration device according to claim 6, characterized in that: The bracket can be fixed to the ground, or the bracket can be fixed to a non-moving part of the multi-axis turntable.

10. A multi-axis turntable calibration method, characterized in that: The method is based on the multi-axis turntable calibration device according to claim 6, including an angular velocity calibration mode and an angular position calibration mode: The multi-axis turntable calibration device is installed to the center of the rotating shaft, the magnetic switch is turned on, the multi-axis turntable is started, and calibration begins; Angular velocity calibration mode: the calibration points of the multi-axis turntable are set according to the calibration specification, the multi-axis turntable calibration device rotates with the multi-axis turntable, and the circular grating reading head (6) feeds back the data required for angular velocity calibration to the computer (7) for processing to obtain the real-time angular velocity calibration parameters of the turntable; Angular position calibration mode: the calibration points of the multi-axis turntable are set according to the calibration specifications, the multi-axis turntable calibration device rotates with the multi-axis turntable, and the circular grating reading head (6) feeds back the data required for angular position calibration to the computer (7) for processing to obtain the real-time angular position calibration parameters of the turntable.

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