An inertial measurement unit calibration device and calibration method

Abstract

This invention provides an inertial measurement unit (IMU) calibration device and method. The device comprises a hexahedral frame including an XYZ three-axis slide rail unit. Each XYZ three-axis slide rail unit includes an X-axis track groove, a Y-axis track groove, and a Z-axis track groove. Each track groove includes multiple sets of track grooves. Each set of track grooves houses a mounting plate assembly, which can slide back and forth along the corresponding axis direction on the track groove. Each set of X-axis track grooves includes a first track groove disposed on the xoz surface and a smaller track groove disposed on a first frame corresponding to the position of the first track groove. The first frame is disposed opposite to the xoz surface. Each set of Y-axis track grooves includes... The invention comprises a second track groove on the xoy plane and a smaller track groove on a second frame corresponding to the position of the second track groove, the second frame being positioned opposite to the xoy plane; each group of track grooves on the Z-axis includes a third track groove on the zoy plane and a smaller track groove on a third frame corresponding to the position of the third track groove, the third frame being positioned opposite to the zoy plane; the invention fully utilizes the internal space of the box, improving space utilization, increasing the number of items calibrated at one time, enabling rapid installation and disassembly of multiple sets of products in a single operation along the X, Y, and Z axes, and improving the assembly accuracy of the products through pin hole fitting.

Description

Technical Field

[0001] This invention belongs to the field of inertial measurement unit calibration technology, and particularly relates to an inertial measurement unit calibration device and calibration method. Background Technology

[0002] Inertial measurement units (IMUs) are widely used in control systems for drones, unmanned vehicles, missiles, submarines, and other applications. Gyroscopes, accelerometers, and other inertial components are essential parts of IMUs. These components (gyroscopes, accelerometers) have inherent error sources during processing, manufacturing, and assembly, necessitating precise calibration of the IMU to improve its measurement accuracy.

[0003] The existing calibration fixture for the dual-axis rotary table is a hexahedral box structure. The bottom surface is installed on the rotary table, and the remaining 5 faces are used to install the inertial measurement unit in three axes. The installation and disassembly are cumbersome, the space utilization rate inside the box is low, and the number of inertial measurement units calibrated at one time is small and the efficiency is low. Summary of the Invention

[0004] To address the technical problems in existing technologies, such as cumbersome installation and disassembly of inertial measurement units (IMUs) in three axes, low space utilization within the box, and low efficiency in calibrating a small number of IMUs at a time, this invention provides an IMU calibration device and method that enables rapid assembly and disassembly in three directions.

[0005] In a first aspect, embodiments of the present invention provide an inertial measurement unit calibration device, comprising: a hexahedral frame (1) and a mounting plate assembly (19);

[0006] The hexahedral frame (1) includes an XYZ three-axis slide rail unit, which includes an X-axis track groove, a Y-axis track groove and a Z-axis track groove. Each track groove includes multiple sets of track grooves. Each set of track grooves is used to place a mounting plate assembly (19). The mounting plate assembly (19) can slide back and forth on the track groove along the corresponding axis direction.

[0007] Each set of X-axis track slots includes a first track slot (8-1) disposed on the xoz surface (7) and a small track slot (8-2) disposed on the first frame (26) corresponding to the position of the first track slot (8-1). The first frame (26) is disposed opposite to the xoz surface (7).

[0008] Each set of Y-axis track slots includes a second track slot (3-1) disposed on the xoy plane (27) and a small track slot (3-2) disposed on the second frame (30) corresponding to the position of the second track slot (3-1). The second frame (30) is disposed opposite to the xoy plane (27).

[0009] Each set of Z-axis track slots includes a third track slot (13-1) set on the zoy plane (2) and a small track slot (13-2) set on the third frame (28) corresponding to the position of the third track slot (13-1). The third frame (28) is set opposite to the zoy plane.

[0010] The hexahedral frame (1) can satisfy the four mounting plate assemblies (19) to slide along the track groove in the X, Y and Z directions respectively by pushing and pulling, and achieve high-precision positioning of the hexahedral frame (1) and the mounting plate assembly (19) by the pin holes on both sides.

[0011] The mounting plate assembly (19) includes a mounting plate (31).

[0012] After the mounting plate assembly (19) is slid into place, the front diamond pin (21) and the front cylindrical pin (20) are inserted into the hexahedral frame (1), and the rear diamond pin (23) and the rear cylindrical pin (22) are inserted into the hexahedral frame (1).

[0013] Among them, the rear diamond pin (23) and the rear cylindrical pin (22) are provided with internal hexagonal cylindrical head non-removable screws (24) for fixing the mounting plate (31) to the hexagonal square frame (1).

[0014] Among them, the plane formed by the center lines of the front diamond pin (21) and the front cylindrical pin (20) is less than 0.01mm parallel to the plane formed by the center lines of the rear diamond pin (23) and the rear cylindrical pin (22), which facilitates the positioning of the mounting plate assembly (19) and the hexahedral frame (1).

[0015] Each set of track grooves in each axis has two first positioning holes at the front end and two second positioning holes and two mounting holes at the rear end. The first positioning holes, second positioning holes and mounting holes are all located on the hexahedral frame (1).

[0016] The two first positioning holes are respectively positioned by the front diamond pin (21) and the front cylindrical pin (20), the two second positioning holes are respectively positioned by the rear diamond pin (23) and the rear cylindrical pin (22), and the two mounting holes are connected by the internal hexagonal head non-removable screw (24).

[0017] For each axis track groove, the parallelism between the plane formed by the center lines of the two second positioning holes at the rear end and the plane formed by the center lines of the two first positioning holes at the front end is less than 0.01 mm.

[0018] For the X-axis track groove, the parallelism between the plane formed by the center lines of the two first positioning holes in each group and the xoy plane is 0.01mm, and the parallelism between the plane formed by the center lines of the two second positioning holes in each group and the xoy plane is 0.01mm.

[0019] For the Y-axis and Z-axis track grooves, the perpendicularity of the plane formed by the center lines of the two first positioning points in each group to the xoy plane is 0.01mm, and the perpendicularity of the plane formed by the center lines of the two second positioning holes in each group to the xoy plane is 0.01mm.

[0020] For the Y-axis track groove, the perpendicularity between the plane formed by the center lines of the two first positioning points of each group and the plane formed by the center lines of the two first positioning points of each group of the Z-axis track groove is 0.01mm.

[0021] Furthermore, the mounting plate assembly (19) also includes a mounting handle (25) located in the middle of the rear end for easy operation.

[0022] Furthermore, the bottom surface of the mounting plate assembly (19) is provided with multiple mounting holes for mounting the inertial measurement unit, and the number of mounting holes can be adjusted appropriately according to the size of the inertial measurement unit.

[0023] Optionally, the front diamond pin (21), the front cylindrical pin (20), the rear diamond pin (23), and the rear cylindrical pin (22) are all fixed to the hexahedral frame (1) by locking nuts 26.

[0024] In a second aspect, a calibration method for the inertial measurement unit calibration device described in the first aspect is provided, comprising:

[0025] When calibration is required, an inertial measurement unit (29) is installed at the bottom of the mounting plate (31) of the mounting plate assembly (19);

[0026] Place the mounting plate assembly (19) in the X-axis track groove and slide the mounting plate assembly (19) forward along the X-axis direction on the track groove. After tightening, start the turntable according to the calibration procedure and obtain the installation angle and scale coefficient of the gyroscope and accelerometer in the inertial measurement unit (29) through the testing equipment. The dual-axis turntable rotates around the Z-axis at a high speed, while the other axis is locked, and the angular rate of the Z-axis gyroscope in the inertial measurement unit (29) is tested.

[0027] The mounting plate assembly (19) is placed in the Y-axis track groove and the mounting plate assembly (19) is slid forward along the Y-axis direction on the track groove. After fastening, the dual-axis turntable rotates at a high speed around the Z-axis, and the other axis is locked. The angular rate of the Y-axis gyroscope in the inertial measurement unit (29) is tested.

[0028] The mounting plate assembly (19) is placed in the Z-axis track groove and slid forward along the Z-axis direction on the track groove. After fastening, the dual-axis turntable rotates at a high speed around the Z-axis while the other axis is locked. The angular rate of the X-axis gyroscope in the inertial measurement unit (29) is tested.

[0029] The beneficial effects of this invention are at least as follows:

[0030] This invention makes full use of the internal space of the box, improves space utilization, increases the number of calibrations at one time, enables rapid installation and disassembly of multiple sets of products (inertial measurement units) in a single operation, and improves the assembly accuracy of the products through pin hole mating. Attached Figure Description

[0031] Figure 1 This is a three-dimensional outline view of an inertial measurement unit calibration device according to the present invention;

[0032] Figure 2 This is a schematic diagram of the mounting plate assembly structure of an inertial measurement unit calibration device according to the present invention;

[0033] Figure 3 This is a schematic diagram of the hexahedral frame structure of an inertial measurement unit calibration device according to the present invention;

[0034] Figure 4 This is a schematic diagram of the mounting plate assembly and the inertial measurement unit of an inertial measurement unit calibration device according to the present invention. Detailed Implementation

[0035] To make the objectives, technical solutions, and advantages of the present invention clearer, the embodiments of the present invention will be described in detail below with reference to the accompanying drawings. It should be noted that, unless otherwise specified, the embodiments and features described in this application can be arbitrarily combined with each other.

[0036] This device, based on a dual-axis turntable, enables rapid installation and calibration along three axes. It is easy, quick, and has high assembly accuracy. It makes full use of the internal space of the square box, allowing for the calibration of a large number of samples at once with high efficiency.

[0037] This invention makes efficient use of the structural space on a dual-axis turntable, enabling the installation of multi-layer products within the cavity. The push-pull installation method improves the efficiency of assembly and disassembly during product calibration, effectively ensuring installation consistency. One embodiment of this invention provides an inertial measurement unit calibration device; please refer to [link to relevant documentation]. Figure 1 As an example of installing a four-layer product, the inertial measurement unit calibration device includes: a hexahedral frame 1 and a mounting plate assembly 19.

[0038] Among them, the hexahedral box 1 includes an XYZ three-axis slide rail unit;

[0039] The XYZ three-axis slide rail unit includes an X-axis slide rail, a Y-axis slide rail, and a Z-axis slide rail. Each axis slide rail contains multiple sets of slide rails. Each set of slide rails is used to place a mounting plate assembly 19. The mounting plate assembly 19 can slide back and forth on the slide rail along the corresponding axis direction. Figure 2 ;

[0040] Each set of X-axis track slots includes a first track slot 8-1 disposed on the xoz plane 7 (composed of the x-axis and z-axis), and a small track slot 8-2 disposed on the first frame 26 corresponding to the position of the first track slot 8-1. The first frame 26 is disposed opposite to the xoz plane 7.

[0041] Each set of Y-axis track slots includes a second track slot 3-1 disposed on the xoy plane 27 (composed of the x-axis and y-axis), and a small track slot 3-2 disposed on the second frame 30 corresponding to the position of the second track slot 3-1. The second frame 30 is disposed opposite to the xoy plane 27.

[0042] Each set of Z-axis track slots includes a third track slot 13-1 set on the zoy plane 2 (composed of the y-axis and z-axis), and a small track slot 13-2 set on the third frame 28 corresponding to the position of the third track slot 13-1. The third frame 28 is set opposite to the zoy plane 2.

[0043] In one embodiment, please refer to Figure 3 Mounting plate assembly 19 includes mounting plate 31.

[0044] After the mounting plate 31 slides into place, the front diamond pin 21 and the front cylindrical pin 20 are inserted into the hexahedral frame, and the rear diamond pin 23 and the rear cylindrical pin 22 are inserted into the hexahedral frame. This facilitates the positioning of the mounting plate assembly after it is in place.

[0045] Furthermore, a hexagonal head screw 24 is provided below the rear diamond pin 23 and the rear cylindrical pin 22 to fix the mounting plate 31 to the hexagonal frame, see... Figure 2 .

[0046] The plane formed by the center lines of the front diamond pin 21 and the front cylindrical pin 20 has a parallelism of less than 0.01mm with the plane formed by the center lines of the rear diamond pin 23 and the rear cylindrical pin 22, which facilitates the positioning of the mounting plate assembly with the hexahedral frame.

[0047] Please see Figure 1 Each set of track slots on each axis has two first positioning holes at the front end and two second positioning holes and two mounting holes at the rear end. The first positioning holes, second positioning holes, and mounting holes are all located on the hexahedral frame 1.

[0048] Please see Figure 2 The two first positioning holes are respectively positioned by engaging with the front diamond pin 21 and the front cylindrical pin 20, and the two second positioning holes are respectively positioned by engaging with the rear diamond pin 23 and the rear cylindrical pin 22. The two mounting holes are connected by engaging with the internal hexagonal head non-removable screw 24.

[0049] See Figure 1For each track groove, the parallelism between the plane formed by the center lines of the two second positioning holes at the rear end and the plane formed by the center lines of the two first positioning holes at the front end is less than 0.01 mm.

[0050] For the X-axis track groove, the parallelism between the plane formed by the center lines of the two first positioning holes in each group and the xoy plane is 0.01 mm. The parallelism between the plane formed by the center lines of the two second positioning holes in each group and the xoy plane is 0.01 mm.

[0051] For the Y-axis and Z-axis track grooves, the perpendicularity of the plane formed by the center lines of the two first positioning points in each group to the xoy plane is 0.01 mm. The perpendicularity of the plane formed by the center lines of the two second positioning holes in each group to the xoy plane is also 0.01 mm.

[0052] For the Y-axis track groove, the perpendicularity between the plane formed by the center lines of the two first positioning points of each group and the plane formed by the center lines of the two first positioning points of each group of the Z-axis track groove is 0.01mm.

[0053] In another embodiment, please refer to Figure 2 The mounting plate assembly 19 also includes a mounting handle 25 located in the middle of the rear end, which facilitates workers to quickly push and pull the mounting plate.

[0054] Further, please see Figure 2 and Figure 4 The bottom surface of the mounting plate 31 is provided with multiple mounting holes for mounting the inertial measurement unit 29. In practical applications, the number of mounting holes can be adjusted appropriately according to the size of the inertial measurement unit.

[0055] Please see Figure 3 The front diamond pin 21, the front cylindrical pin 20, the rear diamond pin 23, and the rear cylindrical pin 22 are all fixed to the hexahedral frame 1 by locking nuts 26.

[0056] An embodiment of the present invention also provides a method for using an inertial measurement unit calibration device, see below. Figures 1 to 4 It includes the following steps:

[0057] Step 1: When calibration is required, install the inertial measurement unit 29 on the bottom of the mounting plate 31 of the mounting plate assembly 19.

[0058] Step 2: Place the mounting plate assembly 19 in the X-axis track groove and slide the mounting plate assembly 19 forward along the X-axis direction on the track groove. After tightening, start the turntable according to the calibration procedure and obtain the installation angle and scale coefficient of the gyroscope and accelerometer in the inertial measurement unit 29 through the testing equipment; rotate the dual-axis turntable around the Z-axis at a high speed, lock the other axis, and test the angular rate of the Z-axis gyroscope in the inertial measurement unit 29.

[0059] Step 3: Place the mounting plate assembly 19 in the Y-axis track groove and slide the mounting plate assembly 19 forward along the Y-axis direction on the track groove. After tightening, the dual-axis turntable rotates at a high speed around the Z-axis, while the other axis is locked. Test the angular rate of the Y-axis gyroscope in the inertial measurement unit 29.

[0060] Step 4: Place the mounting plate assembly 19 in the Z-axis track groove and slide the mounting plate assembly 19 forward along the Z-axis direction on the track groove. After tightening, the dual-axis turntable rotates at a high speed around the Z-axis, while the other axis is locked. Test the angular rate of the X-axis gyroscope in the inertial measurement unit 29.

[0061] Through the embodiments of the present invention, it is possible not only to test the scale coefficients, installation angles, and angular rates of three-axis gyroscopes and accelerometers, but also to save space, increase the number of calibrations per calibration, facilitate installation and disassembly, and ensure high reliability.

[0062] The above description merely illustrates the embodiments of this application, and while it is quite specific and detailed, it should not be construed as limiting the scope of the patent. It should be noted that those skilled in the art can make various modifications and improvements without departing from the concept of this application, and these all fall within the protection scope of this application. Furthermore, any parts not detailed in this application are conventional techniques.

Claims

1. An inertial measurement unit calibration device, characterized in that, include: A hexahedral frame (1) and a mounting plate assembly (19); wherein the hexahedral frame (1) includes an XYZ three-axis slide rail unit, the XYZ three-axis slide rail unit includes an X-axis track groove, a Y-axis track groove and a Z-axis track groove, each track groove includes multiple sets of track grooves, each set of track grooves is used to place a mounting plate assembly (19), the mounting plate assembly (19) can slide back and forth on the track groove along the corresponding axis direction; each set of track grooves of the X-axis track groove includes a first track groove (8-1) set on the xoz surface (7), and a small track groove (8-2) set on the first frame (26) corresponding to the position of the first track groove (8-1), the first frame (26) 6) The Y-axis track groove is set opposite to the xoz plane (7); each set of track grooves includes a second track groove (3-1) set on the xoy plane (27) and a small track groove (3-2) set on the second frame (30) corresponding to the position of the second track groove (3-1), the second frame (30) being set opposite to the xoy plane (27); each set of track grooves of the Z-axis track groove includes a third track groove (13-1) set on the zoy plane (2) and a small track groove (13-2) set on the third frame (28) corresponding to the position of the third track groove (13-1), the third frame (28) being set opposite to the zoy plane (2); The mounting plate assembly (19) includes a mounting plate (31). After the mounting plate (31) is slid into place, it is inserted into the hexahedral frame (1) using a front-end diamond pin (21) and a front-end cylindrical pin (20), and is inserted into the hexahedral frame (1) using a rear-end diamond pin (23) and a rear-end cylindrical pin (22). Below the rear diamond pin (23) and the rear cylindrical pin (22) are provided internal hexagonal head non-removable screws (24) for fixing the mounting plate (31) to the hexagonal square frame (1); The bottom surface of the mounting plate (31) is provided with multiple mounting holes for mounting the inertial measurement unit (29).

2. The apparatus according to claim 1, characterized in that, The parallelism between the plane formed by the center lines of the front diamond pin (21) and the front cylindrical pin (20) and the plane formed by the center lines of the rear diamond pin (23) and the rear cylindrical pin (22) is less than 0.01 mm.

3. The apparatus according to claim 2, characterized in that, Each set of track slots in each axis has two first positioning holes at the front end, two second positioning holes and two mounting holes at the rear end, and the first positioning holes, second positioning holes and mounting holes are all located on a hexagonal cube (1). The two first positioning holes are respectively positioned by the front end diamond pin (21) and the front end cylindrical pin (20), and the two second positioning holes are respectively positioned by the rear end diamond pin (23) and the rear end cylindrical pin (22). The two mounting holes are connected by the internal hexagonal head non-removable screw (24). For each axis track slot, the parallelism between the plane formed by the center lines of the two second positioning holes at the rear end and the plane formed by the center lines of the two first positioning holes at the front end is less than 0.01 mm. For the X-axis track groove, the parallelism between the plane formed by the center lines of the two first positioning points in each group and the xoy plane is 0.01 mm, and the parallelism between the plane formed by the center lines of the two second positioning holes in each group and the xoy plane is 0.01 mm. For the Y-axis and Z-axis track grooves, the perpendicularity between the plane formed by the center lines of the two first positioning points in each group and the xoy plane is 0.01 mm, and the perpendicularity between the plane formed by the center lines of the two second positioning holes in each group and the xoy plane is 0.01 mm. For the Y-axis track groove, the perpendicularity between the plane formed by the center lines of the two first positioning points in each group and the plane formed by the center lines of the two first positioning points in each group of the Z-axis track groove is 0.01 mm.

4. The apparatus according to claim 1, characterized in that, The mounting plate assembly (19) also includes a mounting handle (25) located at the rear center.

5. The apparatus according to claim 1, characterized in that, The front diamond pin (21), the front cylindrical pin (20), the rear diamond pin (23), and the rear cylindrical pin (22) are all fixed to the hexahedral frame (1) by locking nuts (26).

6. A calibration method for an inertial measurement unit calibration device according to any one of claims 1 to 5, characterized in that, include: When calibration is required, an inertial measurement unit (29) is installed at the bottom of the mounting plate (31) of the mounting plate assembly (19); the mounting plate assembly (19) is placed in the X-axis track groove, and the mounting plate assembly (19) slides forward along the X-axis direction on the track groove. After tightening, the turntable is started according to the calibration procedure, and the installation angle and scale coefficient of the gyroscope and accelerometer in the inertial measurement unit (29) are obtained through the testing equipment; the dual-axis turntable rotates at a high speed around the Z-axis, and the other axis is locked to test the angular rate of the Z-axis gyroscope in the inertial measurement unit (29); The mounting plate assembly (19) is placed in the Y-axis track groove and slides forward along the Y-axis direction on the track groove. After being secured, the dual-axis turntable rotates at a high speed around the Z-axis, while the other axis is locked. The angular rate of the Y-axis gyroscope in the inertial measurement unit (29) is tested. The mounting plate assembly (19) is placed in the Z-axis track groove and slides forward along the Z-axis direction on the track groove. After being secured, the dual-axis turntable rotates at a high speed around the Z-axis, while the other axis is locked. The angular rate of the X-axis gyroscope in the inertial measurement unit (29) is tested. The mounting plate assembly (19) includes a mounting plate (31). After the mounting plate (31) is slid into place, it is inserted into the hexahedral frame (1) using a front-end diamond pin (21) and a front-end cylindrical pin (20), and is inserted into the hexahedral frame (1) using a rear-end diamond pin (23) and a rear-end cylindrical pin (22). Below the rear diamond pin (23) and the rear cylindrical pin (22) are provided internal hexagonal head non-removable screws (24) for fixing the mounting plate (31) to the hexagonal square frame (1); The bottom surface of the mounting plate (31) is provided with multiple mounting holes for mounting the inertial measurement unit (29).

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