A normal vector measurement and calibration device and method for a four-channel laser displacement sensor

Abstract

The present invention discloses a normal vector measurement and calibration device and method for a four-channel laser displacement sensor, belonging to the technical field of automatic drilling and riveting technology for digital aircraft assembly. The device comprises a base, a ring gauge, a silicon wafer base, a silicon wafer, a silicon wafer fixing plate, and a magnetic protective cover. The base is fixedly connected to the ring gauge, the silicon wafer base, and the silicon wafer fixing plate, and the silicon wafer is fixedly clamped between the silicon wafer base and the silicon wafer fixing plate. The magnetic protective cover is magnetically connected to the silicon wafer fixing plate. A center hole is provided at the center of the silicon wafer, and the center hole and the center through hole on the ring gauge are coaxial. The surface roughness of the silicon wafer is smaller than that of the ring gauge. A large center hole is provided on the silicon wafer fixing plate through which the laser line of the four-channel laser displacement sensor can pass and illuminate the silicon wafer surface. The present invention uses the ring gauge and the silicon wafer to separate the hole to be measured and the surface to be measured into two parts. Compared with direct measurement using the ring gauge, the measurement results are more stable and reliable.

Description

Technical Field

[0001] The present invention relates to the technical field of automatic drilling and riveting for digital assembly of aircraft, and in particular to a normal vector measurement and calibration device and method for a four-channel laser displacement sensor. Background Art

[0002] Normal measurement technology is crucial and widely used in areas such as aircraft panel normal measurement and automated hole drilling. Laser displacement sensors, with their non-contact, fast measurement speed, and high resolution, are widely used in non-contact normal measurement. A normal measurement system typically includes four laser displacement sensors, forming a four-channel laser displacement sensor.

[0003] Before using a four-channel laser displacement sensor to measure the normal vector, it must be calibrated. A common method involves rotating the sensor relative to the standard ring gauge, using the through-hole direction as the axis, and performing multiple measurements. The measured normal vectors of the ring gauge through-hole are then summed to obtain a reference vector, completing the normal vector measurement calibration. However, the strict verticality requirements for the through-hole of the standard ring gauge make the manufacturing of the standard ring gauge difficult and costly. Furthermore, due to the high measurement accuracy of the laser displacement sensor, the flatness of the ring gauge surface directly affects the normal vector calibration.

[0004] Based on the above situation, it is urgent to design a calibration device to improve the accuracy of the ring gauge normal vector measurement. Summary of the Invention

[0005] The present invention aims to solve the above-mentioned problems existing in the normal vector measurement of ring gauges in the prior art. It proposes a normal vector measurement and calibration device for a four-channel laser displacement sensor. It also proposes a normal vector measurement and calibration method for a four-channel laser displacement sensor. A ring gauge and a silicon wafer are used to separate the hole to be measured and the surface to be measured into two parts. Compared with direct measurement with a ring gauge, the measurement results are more stable and reliable.

[0006] In order to achieve the above-mentioned object of the invention, the technical solution of the present invention is as follows:

[0007] A normal vector measurement and calibration device for a four-channel laser displacement sensor, characterized in that it includes a base, a ring gauge, a silicon wafer base, a silicon wafer, a silicon wafer fixing plate and a magnetic protective cover; the base is fixedly connected to the ring gauge, the silicon wafer base and the silicon wafer fixing plate, and the silicon wafer is fixedly clamped between the silicon wafer base and the silicon wafer fixing plate; the magnetic protective cover and the silicon wafer fixing plate are magnetically connected; a center hole is provided at the center of the silicon wafer, the center hole and the center through hole on the ring gauge are coaxial, the surface roughness of the silicon wafer is smaller than that of the ring gauge, and a large center hole is provided on the silicon wafer fixing plate through which the laser line of the four-channel laser displacement sensor can pass and irradiate the surface of the silicon wafer.

[0008] Furthermore, a groove of the same size as the ring gauge is provided on the top disk of the base, and radial screw holes are provided on the outer side surface of the top disk, and axial screw holes are provided on the bottom surface of the groove.

[0009] Furthermore, the ring gauge is placed in the groove of the base and is fixed by radial screws on the top disk of the base, and the axial screws on the bottom surface of the groove are used to adjust the posture of the ring gauge.

[0010] Furthermore, the silicon wafer base is provided with a groove of the same size as the silicon wafer, and is provided with a through hole coaxial with the center through hole of the ring gauge, a screw hole for connecting to the base, and a screw hole for connecting to the silicon wafer fixing plate.

[0011] Furthermore, the center hole of the silicon wafer is larger than the center through hole on the ring gauge, and the silicon wafer is fixed on the silicon wafer base by a silicon wafer fixing plate and screws.

[0012] Furthermore, the central large hole on the silicon wafer fixing plate is coaxial with the central through hole of the ring gauge to ensure that the laser point of the laser displacement sensor falls on the silicon wafer. A number of serrations are evenly spaced on the inner edge of the central large hole, and the direction of the serrations all points to the center of the silicon wafer fixing plate.

[0013] Furthermore, the magnetic protective cover is used to protect the silicon wafer from being scratched, and a through hole is left at the center thereof. The position of the magnet on the magnetic protective cover corresponds to the position of the magnet on the silicon wafer fixing plate.

[0014] The present invention also provides a normal vector measurement calibration method for a four-channel laser displacement sensor, which is performed using the above-mentioned detection device and includes the following steps:

[0015] Step 1. Place the ring gauge into the base groove and level it with screws before securing it.

[0016] Step 2: Fix the silicon wafer base to the base with screws, and then place the silicon wafer on the silicon wafer base;

[0017] Step 3: After clamping the silicon wafer, connect the silicon wafer base and the silicon wafer fixing plate with screws;

[0018] Step 4. Cover the silicon wafer fixing plate with a magnetic protective cover. Insert the core rod located in the middle of the four-channel laser displacement sensor through the through hole on the magnetic protective cover until it reaches the through hole of the ring gauge.

[0019] Step 5: Remove the magnetic protective cover, and rotate the four-channel laser displacement sensor several times relative to the normal vector measurement and calibration device with the core rod insertion direction as the axis to measure the normal vector of the ring gauge through hole;

[0020] Step 6: Use the vector addition method to obtain the reference vector by using the normal vectors of the ring gauge through hole measured several times, and complete the normal vector measurement calibration of the four-channel laser displacement sensor.

[0021] In summary, the present invention has the following advantages:

[0022] (1) The present invention fixes the ring gauge through a designed base. At the same time, an axial screw hole for adjusting the ring gauge posture is provided in the groove of the base. The ring gauge can be adjusted through the axial screw hole so that the central through hole is perpendicular to the surface of the silicon wafer. The silicon wafer base is coaxially fixed to the base, and a silicon wafer with good flatness is mounted on the front end of the ring gauge in conjunction with the silicon wafer fixing plate. The four laser points of the four-channel laser sensor are irradiated on the silicon wafer, thereby replacing the solution of directly irradiating the ring gauge, achieving the effect of separating the "hole to be measured and the surface to be measured", thereby reducing the measurement error caused by the uneven surface of the ring gauge and improving the measurement accuracy.

[0023] (2) The present invention can effectively calibrate the normal vector measurement of the four-channel laser displacement sensor to ensure the accuracy of the normal vector measurement. Compared with direct measurement with a ring gauge, the measurement results are more stable and reliable;

[0024] (3) The present invention can realize the normal vector measurement and calibration of holes of different specifications by placing ring gauges with different through-hole diameters through the structural design of the normal vector measurement and calibration device;

[0025] (4) In the present invention, the design of the magnetic protective cover of the normal vector measurement and calibration device can reduce the risk of the silicon wafer being scratched. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 It is a schematic diagram of the overall structure of the present invention;

[0027] Figure 2 This is a schematic diagram of the base and fastening screws of the present invention;

[0028] Figure 3 This is a schematic diagram of the base and posture adjustment screws of the present invention;

[0029] In the picture:

[0030] 1. Base, 2. Ring gauge, 3. Silicon wafer base, 4. Silicon wafer, 5. Silicon wafer fixing plate, 6. Magnetic protective cover, 7. Groove, 8. Radial screw hole, 9. Axial screw hole, 10. Serration, 11. Screw. DETAILED DESCRIPTION

[0031] In order to illustrate the present invention more clearly, the present invention will be further described below in conjunction with preferred embodiments and drawings. Those skilled in the art should understand that the content described in detail below is illustrative rather than restrictive, and should not be used to limit the scope of protection of the present invention. The terms "first", "second", etc. in the specification and claims of the present invention and the above-mentioned drawings are used to distinguish different objects rather than to describe a specific order. In addition, the terms "including" and "having" and any variations thereof are intended to cover non-exclusive inclusions. For example, a process, method, system, product or device that includes a series of steps or units is not limited to the listed steps or units, but may optionally include steps or units that are not listed, or may optionally include other steps or units that are inherent to these processes, methods or devices.

[0032] Example 1

[0033] Before measuring the normal vector of a four-channel laser displacement sensor, a standard ring gauge 2 is required for calibration. However, due to the existing high requirements for the verticality of the through-holes in the standard ring gauge 2, the standard ring gauge 2 is difficult and expensive to manufacture. Furthermore, due to the high measurement accuracy of laser displacement sensors, the surface flatness of the ring gauge 2 directly affects the normal vector calibration. To address this issue, the present invention provides a normal vector measurement and calibration device for a four-channel laser displacement sensor. This device uses a ring gauge 2 and a silicon wafer 4 to separate the hole and surface to be measured into two parts. Compared to direct measurement using the ring gauge 2, the device achieves more stable and reliable measurement results.

[0034] like Figure 1 As shown, the calibration device includes a base 1, a ring gauge 2, a silicon wafer base 3, a silicon wafer 4, a silicon wafer fixing plate 5, and a magnetic protective cover 6. The base 1 is fixedly connected to the ring gauge 2, silicon wafer base 3, and silicon wafer fixing plate 5. The silicon wafer 4 is positioned between the silicon wafer base 3 and the silicon wafer fixing plate 5, where it is clamped. The magnetic protective cover 6 is magnetically connected to the silicon wafer fixing plate 5.

[0035] In order to better implement the present invention, a groove 7 of the same size as the ring gauge 2 is further provided on the top disc of the base 1 for placing the ring gauge 2. Six radial screw holes 8 are provided on the outer annular surface of the top disc. These radial screw holes 8 pass through the groove 7 toward the center of the base 1 and are used to fix the ring gauge 2. The bottom surface of the groove 7 is parallel to the axis of the base 1 and is evenly spaced around the center. These axial screw holes 9 are used to adjust the posture of the ring gauge 2. It should be noted that the end of the base 1 away from the top disc is a hollow structure, which facilitates the adjustment of the screws 11 in the axial screw holes 9, thereby achieving the adjustment of the posture of the ring gauge 2.

[0036] In this embodiment, the silicon wafer base 3 is an annular ring structure with a groove 7 of the same size as the silicon wafer 4 on its surface, into which the silicon wafer 4 can be mounted. The silicon wafer base 3 is provided with a through hole slightly larger than the diameter of the ring gauge 2, screw holes for connecting to the base 1, and screw holes for connecting to the silicon wafer fixing plate 5. Preferably, the bottom surface of the groove 7 of the silicon wafer base 3 is provided with multiple waist holes to reduce its own weight.

[0037] In order to better implement the present invention, further, a center hole is opened at the center of the silicon wafer 4, the center hole and the center hole of the ring gauge are on the same axis, and the diameter of the through hole is larger than the through hole at the center of the ring gauge 2. The silicon wafer 4 is installed in the groove 7 of the silicon wafer base 3, and then fixed to the silicon wafer base 3 by the silicon wafer fixing plate 5 and the screw 11.

[0038] In this embodiment, Figure 1 As shown, the silicon wafer fixing plate 5 is an annular ring structure with a large opening design to ensure that the laser point of the laser displacement sensor falls on the silicon wafer 4. A number of saw teeth 10 are evenly spaced on the inner edge of the central large hole, and the direction of the saw teeth 10 all points to the center of the silicon wafer fixing plate 5. The saw teeth 10 serve as an angle reference, which can facilitate the four-channel laser sensor to act as an angle reference in subsequent multiple measurements and achieve uniform angle rotation. At the same time, the inwardly extending saw teeth 10 can also play a role in fixing the silicon wafer 4. In this embodiment, the spacing and length of the saw teeth can be designed as needed. A longer saw tooth can be set every few saw teeth to facilitate the fixed angle rotation each time during measurement.

[0039] To further enhance the present invention, in this embodiment, a magnetic protective cover 6 is magnetically connected to the silicon wafer mounting plate 5 to protect the silicon wafer 4 from scratches. A through hole is provided in the center of the magnetic protective cover 6, and the position of the magnets on the magnetic protective cover 6 corresponds to the position of the magnets on the silicon wafer mounting plate 5.

[0040] The working principle of this device is as follows:

[0041] The ring gauge 2 is fixed to the designed base 1. An axial screw hole 9 is provided within the groove 7 of the base 1 to adjust the ring gauge 2's posture. This axial screw hole 9 allows the ring gauge 2 to be adjusted so that its central through-hole is perpendicular to the surface of the silicon wafer 4. The silicon wafer base 3 is coaxially fixed to the base 1. A silicon wafer fixing plate 5 is used to mount a well-flattened silicon wafer 4 on the front end of the ring gauge 2. This allows the four laser points of the four-channel laser sensor to illuminate the silicon wafer 4, replacing the direct illumination of the ring gauge 2. This achieves the effect of separating the "hole to be measured" and the "surface to be measured," thereby reducing measurement errors caused by surface unevenness of the ring gauge 2 and improving measurement accuracy.

[0042] Example 2

[0043] Based on the above-mentioned normal vector measurement and calibration device of a four-channel laser displacement sensor, this embodiment provides a normal vector measurement and calibration method of a four-channel laser displacement sensor, including the following steps:

[0044] Step 1: Place the ring gauge 2 into the groove 7 on the base 1 and level and secure the ring gauge 2 with the axial screw 11; ensure that the central through hole of the ring gauge 2 is perpendicular to the surface to be measured of the silicon wafer 4;

[0045] Step 2: Fix the silicon wafer base 3 to the base 1 with radial screws 11, and then place the silicon wafer 4 on the silicon wafer base 3;

[0046] Step 3: After the silicon wafer base 3 and the silicon wafer fixing plate 5 clamp the silicon wafer 4, use screws 11 to connect the silicon wafer base 3 and the silicon wafer fixing plate 5;

[0047] Step 4: Cover the silicon wafer fixing plate 5 with a magnetic protective cover 6, and insert the core rod located in the middle of the four-channel laser displacement sensor through the through hole of the magnetic protective cover 6 until it reaches the through hole of the ring gauge 2;

[0048] Step 5: Remove the magnetic protective cover 6. Rotate the four-channel laser displacement sensor several times relative to the normal vector measurement and calibration device with the core rod insertion direction as the axis to measure the normal vector of the through hole of the ring gauge 2. For example, rotate according to the 24 teeth 10 on the silicon wafer fixing plate 5 and measure 24 times.

[0049] Step 6: Use the vector addition method to obtain the reference vector by measuring the normal vectors of the through hole of the ring gauge 2 several times, and complete the normal vector measurement calibration of the four-channel laser displacement sensor.

[0050] Although the specific embodiments of the present invention are described in detail in conjunction with the accompanying drawings, this should not be construed as limiting the scope of protection of this patent. Within the scope described by the claims, various modifications and variations that can be made by those skilled in the art without creative work still fall within the scope of protection of this patent.

[0051] The above description is only a preferred embodiment of the present invention and does not limit the present invention in any form. Any simple modification or equivalent change made to the above embodiment based on the technical essence of the present invention shall fall within the scope of protection of the present invention.

Claims

1. A normal vector measurement and calibration device for a four-channel laser displacement sensor, characterized in that: The invention comprises a base (1), a ring gauge (2), a silicon wafer base (3), a silicon wafer (4), a silicon wafer fixing plate (5) and a magnetic protection cover (6); the base (1) is fixedly connected to the ring gauge (2), the silicon wafer base (3) and the silicon wafer fixing plate (5); the silicon wafer (4) is fixedly clamped between the silicon wafer base (3) and the silicon wafer fixing plate (5); the magnetic protection cover (6) is connected to the silicon wafer fixing plate (5) by magnetic attraction; a center hole is provided at the center of the silicon wafer (4); the center hole and the center through hole on the ring gauge (2) are on the same axis; the surface roughness of the silicon wafer (4) is smaller than that of the ring gauge (2); a large center hole is provided on the silicon wafer fixing plate (5) for the laser line of the four-channel laser displacement sensor to pass through and irradiate the surface of the silicon wafer (4); a groove (7) of the same size as the ring gauge (2) is provided on the top disk of the base (1), a radial screw hole (8) is provided on the outer side of the top disk, and an axial screw hole is provided on the bottom surface of the groove (7) (9); the ring gauge (2) is placed in the groove (7) of the base (1) and is fixed by the radial screw (11) of the top disk of the base (1), and the axial screw (11) on the bottom surface of the groove (7) is used to adjust the posture of the ring gauge (2); the silicon wafer base (3) is provided with a groove (7) of the same size as the silicon wafer (4), and is provided with a through hole coaxial with the central through hole of the ring gauge (2), a screw hole for connecting to the base (1) and a screw hole for connecting to the silicon wafer fixing plate (5); the silicon wafer ( The center hole of the ring gauge (4) is larger than the center through hole of the ring gauge (2), and the silicon wafer (4) is fixed to the silicon wafer base (3) by the silicon wafer fixing plate (5) and the screw (11); the center large hole on the silicon wafer fixing plate (5) is coaxial with the center through hole of the ring gauge (2) to ensure that the laser point of the laser displacement sensor falls on the silicon wafer (4), and a plurality of saw teeth (10) are evenly spaced on the inner edge of the center large hole, and the direction of the saw teeth (10) all points to the center of the silicon wafer fixing plate (5).

2. The normal vector measurement and calibration device for a four-channel laser displacement sensor according to claim 1, characterized in that: The magnetic protection cover (6) is used to protect the silicon wafer (4) from being scratched, and has a through hole at its center. The position of the magnet on the magnetic protection cover (6) corresponds to the position of the magnet on the silicon wafer fixing plate (5).

3. A method for calibrating the normal vector of a four-channel laser displacement sensor, using the device for calibrating the normal vector of a four-channel laser displacement sensor according to claim 1 or 2, characterized in that: The following steps are involved: Step 1. Place the ring gauge (2) into the groove (7) of the base (1) and use screws (11) to level and secure the ring gauge (2); Step 2: Fix the silicon wafer base (3) to the base (1) with screws (11), and then place the silicon wafer (4) on the silicon wafer base (3); Step 3: After the silicon wafer (4) is clamped by the silicon wafer base (3) and the silicon wafer fixing plate (5), the silicon wafer base (3) and the silicon wafer fixing plate (5) are connected with screws (11); Step 4: Cover the silicon wafer fixing plate (5) with a magnetic protective cover (6), and insert the core rod located in the middle of the four-channel laser displacement sensor through the through hole on the magnetic protective cover (6) until it reaches the through hole of the ring gauge (2); Step 5: Remove the magnetic protective cover (6), rotate the four-channel laser displacement sensor several times relative to the normal vector measurement calibration device with the core rod insertion direction as the axis, and measure the normal vector of the through hole of the ring gauge (2); Step 6: Use the vector addition method to obtain the reference vector by measuring the normal vectors of the through hole of the ring gauge (2) several times, and complete the normal vector measurement calibration of the four-channel laser displacement sensor.

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