Inertial navigation batch calibration test installation tool

Abstract

The utility model discloses a kind of inertial navigation calibration test installation tool, including base, at least two layers of inertial navigation installation tray, blind insertion butt joint component, inertial navigation compression strip and data acquisition board.Base edge reference leans on face top contact table positioning block to determine angular zero position;The profile of base concave table and tray boss, concave table is same side fillet rectangle towards consistent, straight edge is attached to complete translation and angular positioning in horizontal plane, this shape does not have rotational symmetry, so that each layer can only be positioned in only angular position.Inertial navigation installation position is attached with mounting surface, inertial navigation positioning pin clearance fit, reference leans on face attachment to realize triple restraint;Floating subboard is slid along blind insertion butt joint guide rod to complete insertion, blind insertion butt joint guide pin enters guide hole before insertion pin to complete centering.Each layer tray is independently compressed with inertial navigation compression strip, and the signal and power supply of this layer are led out through a outlet cable with data acquisition board, so that filling, interfacing, compression, wiring process can be completed outside equipment.

Description

Technical Field

[0001] This utility model relates to the field of inertial navigation system testing and calibration technology, and in particular to an installation fixture for fixing multiple MEMS inertial navigation systems on a turntable for batch calibration and testing. Background Technology

[0002] MEMS inertial navigation systems (hereinafter referred to as inertial navigation systems) need to be calibrated and tested on precision testing equipment before leaving the factory to obtain the error model coefficients of the gyroscope and accelerometer. In a mass production environment, in order to improve efficiency, multiple inertial navigation systems usually need to be installed on one device at the same time for batch calibration.

[0003] Inertial navigation system (INS) testing typically requires mounting fixtures to secure the INS to the mounting platform of the test equipment. Taking a certain type of dual-axis temperature-controlled rotary table as an example, its platform is an alloy disc with mounting holes. The disc's edge has dedicated horizontal positioning blocks serving as the angular reference for the fixture, and slip ring interfaces on both sides of the disc are used to lead power and signals to the outside of the equipment. Currently, mounting fixtures for securing INS mainly come in two forms: multi-layer and single-layer structures (see existing technologies such as CN206952818U). Both forms have drawbacks.

[0004] First, all assembly processes consume significant time of the testing equipment. In the existing tooling, inertial navigation systems (INS) need to be individually aligned with holes and screws tightened inside the equipment; connectors need to be manually inserted; and cables need to be individually organized and bundled. All of these processes are completed inside the equipment, and the loading time is directly proportional to the number of INS. With 48 INS, loading and unloading each consume a substantial amount of equipment time. Testing equipment is a relatively expensive and critical resource in the calibration production line, with single test cycles lasting several hours to tens of hours. The time consumed by the assembly process directly reduces the effective utilization rate of the equipment.

[0005] Secondly, the number of cables is physically limited by the number of slip ring channels. Each inertial navigation system (INS) requires at least four signal lines and two power lines. Taking 48 INS as an example, a total of 288 cables need to be led out through the slip rings. Conventional turntables have fewer than 200 slip ring channels, which cannot accommodate this scale of cables. The slip ring channels become a physical bottleneck restricting the batch calibration quantity.

[0006] Third, manual insertion of micro-rectangular connectors can easily damage the pins. The pin pitch of the J30J micro-rectangular connector is only 1.27mm. When manually aligning and inserting them in the confined space inside the equipment, lateral misalignment leading to pin bending or breakage is a common fault, and this failure rate is highly dependent on the operator's experience and feel.

[0007] Fourth, there is a lack of structural means to prevent misassembly. The inertial navigation system body has a regular shape and the multi-layered trays have the same appearance. During the assembly process, there are no structural means to prevent errors such as the inertial navigation system being installed backwards or the trays being misaligned. Usually, these can only be avoided by relying on operating procedures and manual inspection. Utility Model Content

[0008] To address the aforementioned technical problems, this utility model provides a batch calibration and testing installation fixture for inertial navigation systems. Its core concept is to design each inertial navigation system installation tray as a modular unit that can be independently assembled outside the testing equipment and transported as a whole, thus completely decoupling the assembly process from the time occupied by the testing equipment.

[0009] To achieve the above objectives, the present invention adopts the following technical solution: An inertial navigation system (INS) batch calibration test installation fixture includes a base, at least two layers of INS mounting trays, a blind-fit docking assembly, INS pressure strips, and data acquisition boards. The lower surface of the base is a flat surface that fits against the mounting table of the test equipment. Its edges have reference surfaces that abut against the sides of horizontal positioning blocks on the mounting table. The upper surface has a base recess, and the sides have multiple base interfaces corresponding to each layer of the data acquisition boards. The base has through holes extending along its thickness, and tension bolts threaded into these through holes are threaded onto the mounting table. Each layer of inertial navigation system (INS) mounting trays is stacked vertically on top of the base. Each tray has a lower surface protrusion and an upper surface recess. The lower surface protrusion of the bottom tray is embedded in the base recess, and the lower surface protrusions of the upper trays in adjacent layers are embedded in the upper surface recesses of the lower trays. The outlines of the base recess, the lower surface protrusions, and the upper surface recesses are all rounded rectangles on the same side; that is, the two corners at the ends of the same side of the rectangle are rounded, and the other two corners are right angles, and the sides containing the two rounded corners in each outline face the same direction. Each layer of INS mounting trays has vertically penetrating interlayer locking bolt holes. The upper surface of the base has threaded holes aligned vertically with the interlayer locking bolt holes of each layer. At least one interlayer locking bolt passes through the interlayer locking bolt holes of each layer sequentially from the top layer and is threadedly connected to the threaded holes. Each layer of the inertial navigation system (INS) mounting tray has multiple INS mounting positions on its upper surface, two crossbeams located at both ends of the INS mounting positions, and an INS reference surface fixed to the upper surface of the tray and extending along its length. The bottom of each INS mounting position is a mounting surface that fits against the bottom surface of the INS. At least three INS positioning pins are protruding from the mounting surface and are clearance-fitted with the mounting holes on the bottom surface of the INS. The side of each INS mounting position facing away from the INS reference surface is open, forming an opening. The side opposite the opening is the INS reference surface, which is a plane that fits against the side of the INS. At least two blind-mating guide rods are fixed to the inertial navigation reference surface, with one end fixed to the inertial navigation reference surface, the axis perpendicular to the inertial navigation reference surface and spanning the corresponding opening. The blind-mating assembly is located at each opening and includes a floating sub-plate, a micro-rectangular interface female, blind-mating guide pins, and a quick-locking structure. The floating sub-plate has a guide hole, the axis of which is parallel to the axis of the blind-mating guide rod. The floating sub-plate is fitted onto the blind-mating guide rod through the guide hole and can slide along it. The diameter of the guide hole is larger than the outer diameter of the blind-mating guide rod. The micro-rectangular interface female is fixed to the floating sub-plate. At least two blind-mating guide pins are parallel to each other and located on both sides of the micro-rectangular interface female, their axes parallel to the axis of the blind-mating guide rod, and their extension length is greater than the extension length of the electrical pins inside the micro-rectangular interface female. The quick-locking structure includes a pull rod hinged to the inertial navigation mounting tray and connecting rods with their ends hinged to the pull rod and the floating sub-plate, respectively. Each layer of the inertial navigation system (INS) mounting tray is provided with at least one INS pressure strip, with its two ends fixed to two crossbeams on the same layer. The INS pressure strip is located above multiple INS mounting positions. Each layer of the INS mounting tray is provided with at least one data acquisition board, which is equipped with a microcontroller, a multi-channel serial port interface circuit, an Ethernet interface circuit, and an INS power supply circuit. Each micro-rectangular interface female connector on the same layer is connected to the serial port interface circuit and the INS power supply circuit respectively via INS connection cables. Each layer of the data acquisition board is connected to the corresponding base interface via an output cable. The output cable contains a power supply wire connected to the INS power supply circuit and an Ethernet signal wire connected to the Ethernet interface circuit.

[0010] Preferably, one side containing two rounded corners of the same-side rounded rectangle is parallel to the inertial navigation reference surface, and the radius of the rounded corners is 3mm to 8mm. At least two pre-tension springs connect the floating sub-plate and the inertial navigation mounting tray, the force direction of which is parallel to the axis of the blind-fit docking guide pin and points towards the opening. The quick-locking structure also includes a fixed hinge and two movable hinges; the pull rod is a rigid rod integrally formed and hinged to the inertial navigation mounting tray via the fixed hinge; one end of the connecting rod is hinged to the pull rod via one of the movable hinges, and the other end of the connecting rod is hinged to the floating sub-plate via the other movable hinge; the rotational stroke of the pull rod around the fixed hinge crosses the position where the fixed hinge and the two movable hinges are collinear, forming an over-center self-locking mechanism. The connecting rod is an elastic rod; when the pull rod rotates to the position crossing the collinear position, it abuts against the inertial navigation reference surface. The front end of the blind-fit docking guide pin has a ball head section or a tapered guide section. The clearance between the inertial navigation positioning pin and the mounting hole on the bottom surface of the inertial navigation system is 0.1mm to 0.3mm; the difference between the diameter of the guide through hole and the outer diameter of the blind insertion guide rod is 0.2mm to 0.8mm. The inertial navigation system mounting tray has multiple cable routing holes running through its front and back sides, and a cable clamp is provided on the back side; the inertial navigation connecting cable runs from the front to the back side through the cable routing holes and is held by the cable clamp; the data acquisition board is fixed to the back side of the inertial navigation system mounting tray. Tray handles are provided on opposite sides of the inertial navigation system mounting tray.

[0011] To realize the above concept, three problems need to be solved simultaneously: First, the pallet must be able to independently fix the inertial navigation system (INS) of its own layer when detached from other layers; second, the electrical connection of the entire INS layer must be simplified to a single plug-and-play action on the equipment, otherwise individual wiring still needs to be done inside the equipment; third, the pallet handling and stacking process must not damage the positioning reference established outside the equipment. This utility model solves these three problems respectively through the crossbeams and INS pressure strips built into each layer, the data acquisition board and single output cable built into each layer, and the rounded rectangular stop on the same side running through the entire link.

[0012] In terms of reference transfer, the lower surface of the base fits against the mounting platform to determine the horizontal reference, and the reference surface at the edge of the base abuts against the horizontal positioning block on the mounting platform to determine the angular zero position. The contours of the base recess, the lower surface boss of the tray, and the upper surface recess of the tray are all rounded rectangles on the same side, that is, the two corners at the ends of the same side of the rectangle are rounded, and the other two corners are right angles. The four straight sides of the rectangle fit together, restricting the two translational degrees of freedom of the mating parts in the horizontal plane and determining their angular positions; the two rounded corners are concentrated on the same side, so that the contour does not have the inherent 180° rotational symmetry of a normal rectangle, thus allowing each layer of tray and base to be positioned in only one angular position. The two rounded corners in each stop contour have the same orientation, which is the premise that the upper and lower stops can complement each other and that the angular reference can be transferred layer by layer in the same direction. Thus, the angular reference starts from the inertial navigation reference surface, is transferred layer by layer through the stops to the base, and then through the reference surface to the test equipment shaft, forming a complete angular reference chain. It should be noted that for the static multi-position calibration method, the measurement principle of angular rate and specific force is independent of the radial position of the inertial navigation system relative to the axis of rotation. Therefore, this invention does not impose additional structural constraints on the radial translation position of the base relative to the mounting platform, but focuses the positioning accuracy on the angular aspect that truly affects the calibration results.

[0013] In terms of inertial navigation system (INS) positioning, the mounting surface of each INS mounting position is in contact with the bottom surface of the INS, constraining the INS' pitch attitude, roll attitude, and altitude reference. At least three INS positioning pins are clearance-fitted with the corresponding mounting holes on the bottom surface of the INS, used only for coarse positioning during vertical placement to avoid wear and assembly difficulties caused by excessive fit. The corresponding side of the INS is in contact with the INS reference surface, constraining the INS' position along the insertion direction and its azimuth reference around the vertical axis. The main constraint directions of the three sets of constraints do not overlap, and the gap between the positioning pins and the mounting holes is used to absorb pin hole position deviations, avoiding interference and assembly stress caused by redundant constraints.

[0014] In blind mating, one end of the blind mating guide rod is fixed to the inertial navigation reference surface, with its axis perpendicular to the inertial navigation reference surface and extending along the mating direction. The floating sub-plate is fitted onto the blind mating guide rod through a guide hole, and its sliding along the blind mating guide rod constitutes the mating stroke. The radial clearance formed by the guide hole diameter being larger than the rod diameter provides small displacement compensation for the floating sub-plate in both the lateral and vertical directions perpendicular to the mating direction, absorbing alignment deviations caused by accumulated machining tolerances. The blind mating guide pin is parallel to the blind mating guide rod, and its extension length is greater than that of the electrical pin. During the mating stroke, it must enter the guide hole at the inertial navigation end before the pin to complete the alignment. After the floating sub-plate reaches the mating position, it is locked and held by a self-locking quick-locking structure. The preload spring maintains the stable position of the floating sub-plate before the inertial navigation system is in place, and after mating, it continuously presses the inertial navigation system against the inertial navigation reference surface.

[0015] In terms of the clamping structure, each inertial navigation system mounting tray is equipped with a crossbeam and an inertial navigation pressure strip. The pressure strip is fixed to the crossbeam of the tray itself and independently clamps all the inertial navigation systems in the layer from above, without relying on the stacking with other layers.

[0016] In terms of signal aggregation, each tray is equipped with a data acquisition board. All serial port signals and power supplies of the inertial navigation system on this layer are aggregated to the acquisition board through blind-plug assembly and inertial navigation connection cable, and only one output cable is connected to the corresponding base interface. Beneficial effects

[0017] This utility model has the following beneficial effects:

[0018] I. The pallet structure forms a modular unit that can be pre-assembled independently, completely decoupling assembly operations from the occupation of testing equipment. Each pallet layer has its own crossbeam and inertial navigation system (INS) clamping strip, allowing for independent mechanical fixing of the INS in its layer while detached from other layers. Each pallet layer also has its own data acquisition board, where all signals and power supplies from the INS in that layer are converged to the acquisition board via blind-plug assembly and INS connection cables, with only one output cable. Combined with the tool-free, manual operation of the floating blind-plug assembly, all processes—INS loading, electrical connection, clamping, and cable arrangement—can be completed on a workbench outside the testing equipment. When loading into the testing equipment, only three actions are required: pallet stacking and positioning, tightening inter-layer locking bolts, and connecting the output cable. Existing tooling requires individual screw fixing of INS, manual insertion of connectors, and cable arrangement within the equipment, all of which consume equipment operating time. This invention essentially decouples equipment occupation time from the number of INS, relating only to the number of layers. Furthermore, the pre-assembly process can be performed by multiple people in parallel and can overlap with equipment operating time, improving the effective utilization rate of the testing equipment.

[0019] II. A single interface enables electrical connection of the entire inertial navigation system (INS) layer, overcoming the limitation imposed by the number of slip ring channels on batch production. The serial port signals and power supply of each of the 16 INS channels on each layer are aggregated via a data acquisition board and then connected to the corresponding base interface through a single 12-core output cable (8 cores for Ethernet signal, 4 cores for power supply including reserved cores). For 3 layers and 48 INS channels, the number of wires required to cross the slip rings is reduced from 288 in the existing scheme to 36 cores, a reduction of approximately 87.5%. Conventional turntables typically have fewer than 200 slip ring channels. Existing solutions already exceed the physical capacity of slip rings with 48 INS channels. This invention eliminates the slip ring channel limitation on batch production. Furthermore, the electrical connection of the entire INS layer on the equipment is simplified to a single plug-and-play action, a necessary prerequisite for achieving the first effect.

[0020] Third, structural means are used to eliminate pin damage in micro-rectangular connectors, eliminating the need for operator alignment experience. The J30J micro-rectangular connector has a pin pitch of only 1.27mm, and lateral misalignment during manual insertion is the main cause of pin bending and breakage. This invention features a blind-mating guide pin parallel to the blind-mating guide rod, with an extension length greater than the electrical pin. During the insertion stroke, the blind-mating guide pin inevitably enters the inertial navigation end guide hole before the pin to complete alignment. The floating daughter plate is fitted onto the blind-mating guide rod through a guide hole. The radial gap formed by the difference between the hole diameter and the rod diameter provides displacement compensation in both lateral and vertical directions, converting alignment deviation into displacement of the floating daughter plate rather than force on the pin. Physically, the pin cannot contact the inertial navigation end in an oblique posture, and only bears axial force throughout the insertion process. This effect is guaranteed by the structure itself and does not depend on the operator's experience or feel.

[0021] IV. The inertial navigation system (INS) mounting position is structurally designed to eliminate the possibility of reverse installation, and the multi-layer trays are structurally designed to prevent misalignment during stacking. One side of the INS mounting position has an opening for the connector to extend out, and the opposite side is the INS reference surface. If the INS is placed in the wrong orientation, its connector will interfere with the INS reference surface and will not be able to be positioned. The stop joint uses a rounded rectangle with the same orientation on the same side. The rounded corners are concentrated on one side, which destroys the inherent 180° rotational symmetry of the rectangle. Each layer of tray and base can only be positioned in a unique angular position, avoiding misalignment when stacking multi-layer trays with the same appearance, and preventing failure of angular reference transmission. Attached Figure Description

[0022] Figure 1 This is a cross-sectional view of the overall assembly of this utility model.

[0023] Figure 2 Top view of the inertial navigation system mounting tray.

[0024] Figure 3 This is a magnified view of the inertial navigation system installation location.

[0025] Figure 4 This is a diagram of the wiring on the back of the tray.

[0026] Figure 5 This is a magnified view of a part of the quick-locking structure.

[0027] Figure 6 This is a schematic diagram of a signal transmission link.

[0028] 1-Base; 11-Base recess; 12-Reference surface; 13-Base interface; 14-Tightening bolt; 2-Inertial navigation system mounting tray; 21-Leading boss on the lower surface of the tray; 22-Recessed platform on the upper surface of the tray; 23-Tray handle; 24-Interlayer locking bolt; 25-Interlayer locking bolt hole; 31-Crossbeam; 32-Inertial navigation reference surface; 33-Blind insertion guide rod; 34-Inertial navigation pressure strip; 41-Inertial navigation system mounting position; 42-Inertial navigation system positioning pin; 43-Preload spring; 44-Floating subplate; 45-Micro rectangular interface female connector; 46-Blind mating guide pin; 47-Cable routing hole; 48-Cable clamp; 51-Data acquisition board; 52-Output cable; 53-Inertial navigation connection cable; 60 - Quick-locking structure; 61 - Pull rod; 62 - Connecting rod; 63 - Fixed hinge; 64 - Movable hinge. Detailed Implementation

[0029] The technical solution of this utility model will be clearly and completely described below with reference to the accompanying drawings. Taking the batch calibration of a certain type of MEMS inertial navigation system on a dual-axis temperature-controlled turntable as an example, the inertial navigation system has multiple mounting holes on its bottom surface, and the external electrical interface is a micro-rectangular connector located on one side of the inertial navigation system. It should be noted that the dual-axis temperature-controlled turntable is only one application scenario of this utility model; this utility model is also applicable to other test equipment that requires batch installation of inertial navigation systems, such as temperature chambers and vibration tables.

[0030] 1. The reference fit between the base and the mounting surface.

[0031] Reference Figure 1 The base 1 is a plate-like structure with a flat lower surface that fits snugly against the mounting platform of the testing equipment, establishing a horizontal reference for the base relative to the mounting platform. The base 1 has a through hole extending along its thickness, through which a tension bolt 14 passes. The tension bolt 14 passes through the through hole from one side of the top surface of the base and is threaded into a threaded hole on the mounting platform, securing the base 1 to the platform. The side of the base 1 has multiple base interfaces 13, the number of which matches the number of layers in the inertial navigation system mounting tray 2. Each base interface 13 connects to the corresponding layer's outlet cable 52.

[0032] The base 1 has a reference surface 12 on the side of its edge facing the horizontal positioning block. When clamping, first place the base 1 on the mounting table, then make the reference surface 12 abut against the side of the horizontal positioning block to determine the angular zero position of the base relative to the rotating shaft of the test equipment, and then tighten the tension bolt 14.

[0033] 2. The same-side rounded rectangle stop and the angular reference transfer.

[0034] The upper surface of the base 1 is provided with a base recess 11, and the lower surface of the bottom inertial navigation mounting tray 2 is provided with a tray lower surface protrusion 21, which is embedded in the base recess 11; between two adjacent inertial navigation mounting trays 2, the lower surface protrusion 21 of the upper tray is embedded in the upper surface recess 22 of the lower tray.

[0035] The outlines of the aforementioned base recess 11, tray lower surface boss 21, and tray upper surface recess 22 are all same-sided rounded rectangles. That is, of the four corners of the rectangle, the two corners located at both ends of the same side are rounded, and the other two corners are right angles. During mating, the four straight sides of the rectangle fit together, restricting the two translational degrees of freedom of the mating parts in the horizontal plane and determining their angular positions; the end face mating completes the axial reference transfer. Since the two rounded corners are concentrated on the same side, this outline does not have the inherent 180° rotational symmetry of a normal rectangle: when the mating parts rotate 180° around the vertical axis, its rounded corner side will be opposite the right angle side of the mated parts, resulting in clearance at the rounded corners and interference at the right angles, preventing the mating parts from being positioned. Therefore, each layer of inertial navigation mounting tray 2 and base 1 can only be positioned in a single angular position and cannot be installed at other angles.

[0036] In each stop profile, the two rounded corners on the sides face the same direction. That is, the rounded corners of the base recess 11, the lower surface boss 21 of each pallet, and the upper surface recess 22 of the pallet point in the same direction when assembled. If the rounded corners of each stop do not face the same direction, the upper and lower stops will not be able to complement each other, and the angular reference cannot be transferred layer by layer in the same direction. Therefore, consistent rounded corner orientation is a prerequisite for the success of this solution.

[0037] In this embodiment, one side containing the two rounded corners of each stop contour is parallel to the inertial navigation reference surface 32, ensuring that the anti-rotation direction of the stop is consistent with the orientation direction of the inertial navigation, facilitating the unification of the machining reference and the detection reference. The rounded corner radius is 3mm to 8mm, balancing the guiding performance during placement with the interference reliability of the right-angle side. Furthermore, since the base recess 11 and the upper surface recess 22 of the tray are inner contours, the two right angles are difficult to machine into theoretically sharp corners due to the limitation of the milling cutter radius. Therefore, clearance grooves are provided at the two right angles. The size of the clearance grooves is smaller than the chamfer at the corresponding right angle of the boss, to ensure reliable contact of the straight edge and to ensure that the interference prevention function of the right angle side is not affected.

[0038] This forms a complete angular reference chain: the side of the inertial navigation system (INS) is aligned with the INS reference surface 32, determining the INS' orientation relative to the tray; the straight edge of the rounded rectangular stop on the same side is aligned with the asymmetrical rounded corner constraint, determining the orientation of each tray layer relative to the base; the base reference surface 12 rests against the horizontal positioning block, determining the orientation of the base relative to the test equipment's rotating shaft. Compared to the scheme using only annular stops, this method supplements the angular constraints without adding parts, enabling the INS' orientation reference to be reliably transmitted to the test equipment's rotating shaft.

[0039] III. Multi-layer stacking and interlayer locking.

[0040] Each inertial navigation system (INS) mounting tray 2 has vertically penetrating interlayer locking bolt holes 25, and the upper surface of the base 1 has threaded holes aligned vertically with the interlayer locking bolt holes 25 of each layer. During assembly, after the trays are stacked in sequence, at least one interlayer locking bolt 24, starting from the interlayer locking bolt hole 25 of the top INS mounting tray 2, passes through the interlayer locking bolt holes 25 of each subsequent tray and is tightened into the threaded hole of the base 1, thus locking all the stacked INS mounting trays and the base at once. The interlayer locking bolts 24 and the tension bolts 14 together form a complete fastening link from the INS mounting tray through the base to the mounting platform, ensuring that the tooling does not experience relative displacement or detachment during the rotation and turning of the dual-axis turntable.

[0041] IV. Triple positioning constraints and anti-reverse installation structure of the inertial navigation system installation position.

[0042] Reference Figure 2 Each inertial navigation system (INS) mounting tray 2 has multiple INS mounting positions 41 on its upper surface. The INS mounting tray 2 has tray handles 23 on opposite sides for easy handling of single-layer trays.

[0043] The bottom of the inertial navigation system (INS) mounting position 41 is a mounting surface that fits against the bottom surface of the INS, constraining the INS' pitch, roll, and height reference relative to the tray. At least three INS positioning pins 42 protrude from the mounting surface, engaging with at least three mounting holes on the bottom surface of the INS with clearance, for coarse positioning during vertical placement of the INS. In this embodiment, the clearance is 0.1mm to 0.3mm. This clearance avoids problems such as wear between the INS positioning pins and mounting holes, and increased effort during vertical placement caused by excessive clearance. When the clearance is less than 0.1mm, the placement resistance increases significantly; when it is greater than 0.3mm, the constraint effect of coarse positioning weakens.

[0044] The inertial navigation mounting position 41 is open on the side facing the inertial navigation connector to form an opening. On the side opposite to the opening, there is an inertial navigation reference surface 32. The inertial navigation reference surface 32 is a plane that fits against the corresponding side of the inertial navigation, constraining the position of the inertial navigation along the insertion direction and the orientation reference around the vertical axis.

[0045] The main constraint directions of the above three sets of constraints do not overlap: the contact constraint between the inertial navigation system's bottom surface and the mounting surface constrains the pitch and roll rotational degrees of freedom and height; the clearance fit between the inertial navigation system's locating pin and the mounting hole only provides coarse positioning to prevent the inertial navigation system from sliding or disengaging within the cavity; the inertial navigation system's reference surface provides precise positional and azimuth constraints for the insertion direction. The clearance between the inertial navigation system's locating pin and the mounting hole is used to absorb pin hole position deviations, ensuring that multi-pin fits do not experience interference or assembly stress due to redundant constraints.

[0046] This structure also provides a physical means to prevent the inertial navigation system (INS) from being installed backwards: one side of the INS mounting position 41 is open, and the opposite side is a solid barrier called the INS reference surface 32. The INS connector is located on one side of this barrier. If the INS is placed in the wrong orientation, the connector will interfere with the INS reference surface 32 and will not be able to be placed. The operator does not need to judge the orientation of the INS, and an incorrectly installed INS cannot be physically placed.

[0047] V. Inertial navigation reference surface and blind insertion guide rod.

[0048] The inertial navigation reference surface 32 is a component fixed to the upper surface of the inertial navigation mounting tray 2 and extending continuously along the length of the tray. It serves the dual purpose of determining the inertial navigation orientation reference and fixing the blind-fit docking guide rods. At least two blind-fit docking guide rods 33 have one end fixed to the inertial navigation reference surface 32, their axes perpendicular to the inertial navigation reference surface 32 and extending along the insertion direction, spanning the corresponding openings. (Refer to...) Figure 3 The two blind-plug guide rods 33 of the same inertial navigation installation position 41 are located on both sides of the inertial navigation installation position 41, avoiding the inertial navigation body in the lateral direction, so that the floating sub-plate 44 does not interfere with the inertial navigation during the entire stroke of sliding along the blind-plug guide rod.

[0049] VI. Floating blind-mating assembly.

[0050] Reference Figure 3 The floating subplate 44 is provided with a guide through hole, the axis of which is parallel to the axis of the blind mating guide rod 33. The floating subplate 44 is fitted onto the blind mating guide rod 33 through the guide through hole and can slide along the blind mating guide rod 33. This sliding constitutes the insertion stroke of the inertial navigation docking. The diameter of the guide through hole is larger than the outer diameter of the blind mating guide rod 33, with a radial gap between them. In this embodiment, the difference between the hole diameter and the rod diameter is 0.2mm to 0.8mm. This radial gap provides the floating subplate 44 with a small amount of displacement compensation in both the lateral and vertical directions perpendicular to the insertion direction, which is used to absorb the alignment deviation caused by the cumulative tolerance of the machining. This difference should be greater than the maximum lateral alignment deviation allowed by the micro rectangular connector. When the difference is less than 0.2mm, the compensation is insufficient to cover the cumulative tolerance; when it is greater than 0.8mm, the attitude stability of the floating subplate 44 in the no-load state decreases.

[0051] The micro-rectangular interface female socket 45 is fixed to the floating daughter plate 44 by screws, located at the center of the floating daughter plate 44, and its insertion direction is parallel to the axis of the blind mating guide rod 33. At least two blind mating guide pins 46 are parallel to each other and located on both sides of the micro-rectangular interface female socket 45, and their axes are parallel to the axis of the blind mating guide rod 33. The front end of the blind mating guide pin 46 is provided with a ball head section or a tapered guide section, and its extension length is greater than the extension length of the electrical pins inside the micro-rectangular interface female socket 45.

[0052] During the insertion process, the floating subplate 44 advances along the blind mating guide rod 33 towards the inertial navigation direction. The ball head of the blind mating guide pin 46 first contacts the locking screw holes on both sides of the inertial navigation connector. At this time, there is still a safe distance between the electrical pin and the inertial navigation end. If there is a lateral or vertical alignment deviation, the lateral component force generated by the ball head of the blind mating guide pin is transmitted through the floating subplate 44, causing the floating subplate 44 to produce a corresponding lateral or vertical displacement within the radial gap range between the guide hole and the blind mating guide rod, thus completing the correction. After the blind mating guide pin 46 is fully inserted into the screw hole, the floating subplate 44 is constrained to a position coaxial with the inertial navigation plug. Continued advancement allows the electrical pin to be smoothly inserted and the mating completed. Since the extension length of the blind mating guide pin 46 is greater than that of the electrical pin, the pin cannot physically contact the inertial navigation end in an incomplete alignment state, and only bears axial force throughout the process.

[0053] VII. Quick-locking structure and preload spring.

[0054] Reference Figure 5 A quick-locking structure 60 connects the floating subplate 44 to the inertial navigation system mounting tray 2. This structure drives the floating subplate 44 along the blind insertion guide rod 33 to the docking position and locks it in place once it reaches the docking position. The quick-locking structure 60 includes a pull rod 61, a connecting rod 62, a fixed hinge 63, and two movable hinges 64. The pull rod 61 is a rigid rod integrally formed and is hinged to the inertial navigation system mounting tray 2 via the fixed hinge 63. The position of the fixed hinge 63 is fixed, and the pull rod 61 can only rotate around it. One end of the connecting rod 62 is hinged to the pull rod 61 via one of the movable hinges 64, and the other end is hinged to the floating subplate 44 via the other movable hinge 64.

[0055] The operator pulls lever 61, causing it to rotate around fixed hinge 63. This rotation, via movable hinge 64, drives connecting rod 62 to rotate, propelling floating sub-plate 44 along blind-fit docking guide rod 33 to the vicinity of the docking position. Continuing to pull lever 61 ensures that the centers of fixed hinge 63 and the two movable hinges 64 are collinear, at which point connecting rod 62 experiences maximum pressure. After passing this collinear position, the mechanism enters an over-center self-locking state, maintaining lockability without continuous external force. At this point, lever 61 abuts against inertial navigation reference surface 32, forming a limit and providing the operator with clear feedback that docking is complete. The entire locking and releasing operation is performed manually, without the need for additional tools.

[0056] Link 62 is an elastic rod used to absorb the accumulated machining tolerances of the stroke required for the floating sub-plate 44 to reach the mating position. Since manufacturing tolerances exist in aspects such as cavity dimensions, inertial navigation system body dimensions, and connector extension, if link 62 were a rigid rod, the collinear geometric relationship of the three centers would be fixed. If the stroke tolerance is too large, the insertion may not be complete before the mechanism locks; if the stroke tolerance is too small, the mechanism may not be able to cross the collinear position to complete self-locking. The elastic deformation of link 62 provides compressible margin for this rigid geometric relationship.

[0057] Reference Figure 3 At least two preload springs 43 are connected between the floating subplate 44 and the inertial navigation system mounting tray 2. The preload springs 43 are fitted onto the blind mating guide rod 33, and their force direction is parallel to the axis of the blind mating guide pin 46 and points towards the opening, giving the floating subplate 44 a preload tendency toward the inertial navigation connector. When the inertial navigation system is not yet in place and the mating assembly is in an unloaded state, this preload is used to prevent the floating subplate 44 from drifting due to handling bumps or equipment vibration. After the mating is completed, the preload force is transmitted to the inertial navigation system body through the mating of the micro rectangular interface female 45 and the inertial navigation connector, continuously pressing the inertial navigation system against the inertial navigation reference surface 32 to maintain the precise orientation positioning of the inertial navigation system after it is in place.

[0058] 8. Self-supporting structure of inertial navigation pressure bar.

[0059] Reference Figure 2 The upper surface of the inertial navigation mounting tray 2 is provided with a crossbeam 31 at each end of the arrangement direction of each inertial navigation mounting position 41. At least one inertial navigation pressure strip 34 is fixed at both ends to two opposite crossbeams 31 on the same layer, spans over the corresponding inertial navigation mounting position 41, and presses the top surface of the inertial navigation in the corresponding inertial navigation mounting position 41 from above.

[0060] Each inertial navigation system (INS) mounting tray 2 is equipped with INS clamping strips 34, allowing each tray to independently clamp and secure the INS within its layer before being stacked with other layers. Once the INS is filled, blindly mated, and clamping strips are installed, each tray becomes a mechanically self-sustaining and safely transportable unit, independent of whether it has been stacked with other layers. This is the prerequisite for the trays to be assembled and transported as a whole outside of the testing equipment.

[0061] IX. Signal Convergence and Transmission Links.

[0062] Reference Figure 4 and Figure 6Each inertial navigation system (INS) mounting tray 2 has at least one data acquisition board 51. The data acquisition board 51 includes a microcontroller, a multi-channel serial port interface circuit, an Ethernet interface circuit, and an INS power supply circuit. The serial port signal pins of each micro-rectangular interface female connector 45 on the same layer are connected to the serial port interface circuit via INS connection cables 53; the INS power supply circuit is also connected to each micro-rectangular interface female connector 45 via INS connection cables 53. It should be noted that the data acquisition board 51 uses existing multi-serial port server circuitry, and its circuit structure itself is not an improvement of this invention. The improvement of this invention lies in the way the data acquisition board 51 is positioned on the INS mounting tray 2, and its connection structure with the micro-rectangular interface female connector 45, the output cable 52, and the base interface 13.

[0063] The inertial navigation system (INS) mounting tray 2 has multiple cable routing holes 47 running through its front and back, and a cable clamp 48 on the back. The INS connection cables 53 of each INS mounting position 41 run from the front to the back through the corresponding cable routing holes 47, and are clamped by the cable clamp 48 to fix the routing path. All INS connection cables 53 converge to the data acquisition board 51, which is fixed to the back of the INS mounting tray 2 and connected to the base interface 13 of the corresponding layer via an exit cable 52. The exit cable 52 contains an 8-core Ethernet signal wire connected to the Ethernet interface circuit and a 4-core power supply wire (including reserved cores) connected to the INS power supply circuit, for a total of 12 cores. These cores are connected to the external power supply and the host computer via a slip ring on the testing equipment. The number of cores in the power supply wires is determined based on the maximum allowable current of a single slip ring and the total power demand of the INS on this layer, with some cores reserved for future expansion or as redundant paths.

[0064] Taking 3 layers × 16 inertial navigation systems = 48 inertial navigation systems as an example, the 3 outlet cables occupy a total of 36 slip ring channels. Compared with the existing technology where each inertial navigation system has 6 cables that pass directly through the slip ring, totaling 288 cables, the reduction is about 87.5%. Since all electrical connections within the layer are completed outside the equipment, the equipment only needs to complete the outlet cable connection once per layer.

[0065] 10. Temperature adaptability.

[0066] When applied to full-temperature calibration scenarios, the main structural components (base 1, inertial navigation mounting tray 2, crossbeam 31, and inertial navigation reference surface 32) are made of hard aluminum alloy (such as 7075-T6), which has a coefficient of linear expansion close to that of aluminum alloys commonly used for inertial navigation housings. The data acquisition board 51 uses industrial-grade components (operating temperature -40℃ to +85℃), and the core crystal oscillator is a temperature-compensated crystal oscillator (TCXO) to reduce the impact of temperature drift. The connecting rod 62 and preload spring 43 of the quick-locking structure 60 are made of materials resistant to high and low temperatures. The base interface 13 uses a sealed connector adapted to the temperature environment.

[0067] XI. Complete Operating Procedures.

[0068] The core working principle of this invention is to transfer the main assembly work to be completed outside of the testing equipment.

[0069] External preparation stage (can be completed in advance and in parallel, without occupying equipment time): Place each inertial navigation system (INS) vertically into its mounting position 41 from above, inserting the INS positioning pin 42 into the mounting hole, ensuring the bottom surface aligns with the mounting surface. INSsels with incorrect orientation cannot be inserted due to interference between the connector and the INS reference surface 32. Actuate the lever 61 of the quick-locking structure 60 to drive the floating sub-plate 44 along the blind-fit docking guide rod 33 to complete the blind-fit docking; the mechanism self-locks after passing the center. Fix both ends of the INS pressure strip 34 to the crossbeam 31 of this layer's tray, pressing all INSsels firmly from above. Organize the INS connection cables 53 from each mounting position, routing them through the cable routing hole 47 to the back and securing them with cable clamps 48, converging them to the data acquisition board 51. Check that the exit cable 52 is intact. After completing the above steps, this layer's tray becomes a self-supporting unit that can be independently transported.

[0070] Equipment loading stage (determines equipment occupancy time): Place base 1 on the mounting platform, with reference surface 12 abutting against the horizontal positioning block, and tighten tension bolts 14 to secure base 1. Transport the prepared pallet layer by layer to the equipment via pallet handles 23, positioning it along the rounded rectangular stops on the same side; because the two rounded corners of this profile are concentrated on one side and do not have 180° rotational symmetry, and the rounded corners of each stop face the same direction, the pallet can only be placed at one correct angle. After all layers are stacked in place, insert interlayer locking bolts 24 through all layers and tighten them with base 1; connect the outlet cables 52 of each layer to the corresponding base interface 13.

[0071] Preparation work outside the equipment can be handled by multiple operators in parallel, or it can overlap with the testing time of the previous batch of equipment, and neither is included in the equipment occupancy time; the loading work on the equipment only includes three actions: stacking and positioning, bolt tightening, and cable connection, and its time consumption is not related to the number of inertial navigation systems, but only to the number of layers. The furnace unloading operation is the reverse of the above steps.

[0072] The above description is merely a preferred embodiment of this utility model and does not limit the scope of protection of this utility model. Any modifications, equivalent substitutions, and improvements made within the concept and principles of this utility model should be included within the scope of protection of this utility model.

Claims

1. An inertial navigation batch calibration test installation fixture, comprising a base (1) and at least two layers of inertial navigation mounting trays (2); the lower surface of the base (1) is a plane that fits against the test equipment mounting table; each layer of the inertial navigation mounting trays (2) is stacked vertically above the base (1); each layer of the inertial navigation mounting trays (2) has multiple inertial navigation mounting positions (41) on its upper surface. Its features are, It also includes blind-fit docking components, inertial navigation pressure strips (34) and data acquisition boards (51); The base (1) has a reference surface (12) on its edge, which is a plane that abuts against the side of the horizontal positioning block on the mounting platform; the upper surface of the base (1) has a base recess (11), and the side has multiple base interfaces (13) that correspond one-to-one with the data acquisition boards (51) of each layer. Each layer of the inertial navigation mounting tray (2) has a tray lower surface protrusion (21) on its lower surface and a tray upper surface recess (22) on its upper surface. The tray lower surface protrusion (21) of the bottom layer of the inertial navigation mounting tray (2) is embedded in the base recess (11). In the two adjacent layers of the inertial navigation mounting tray (2), the tray lower surface protrusion (21) of the upper layer is embedded in the tray upper surface recess (22) of the lower layer. The outlines of the base recess (11), the tray lower surface protrusion (21), and the tray upper surface recess (22) are all rounded rectangles on the same side. The rounded rectangle on the same side refers to a rectangle in which two corners located at the two ends of the same side are rounded and the other two corners are right angles. The two rounded corners of each rounded rectangle on the same side have the same orientation. Each layer of the inertial navigation mounting tray (2) is provided with interlayer locking bolt holes (25) that pass through vertically. The upper surface of the base (1) is provided with threaded holes, which are aligned vertically with the interlayer locking bolt holes (25) of each layer. At least one interlayer locking bolt (24) passes through the interlayer locking bolt holes (25) of each layer starting from the top layer of the inertial navigation mounting tray (2) and is threadedly connected to the threaded holes. The base (1) is also provided with through holes that pass through the thickness direction, and tension bolts (14) that are threadedly connected to the mounting platform are inserted in the through holes. Each layer of the inertial navigation mounting tray (2) is further provided with two crossbeams (31) located at both ends of the arrangement direction of each inertial navigation mounting position (41), and an inertial navigation reference surface (32) fixed to the upper surface of the inertial navigation mounting tray (2) and extending along its length direction; the bottom of the inertial navigation mounting position (41) is a mounting surface that fits against the bottom surface of the inertial navigation, and at least three inertial navigation positioning pins (42) are protruding on the mounting surface, and the inertial navigation positioning pins (42) are clearance-fitted with the mounting holes on the bottom surface of the inertial navigation; the side of the inertial navigation mounting position (41) facing away from the inertial navigation reference surface (32) is open to form an opening, and the side opposite to the opening is the inertial navigation reference surface (32), and the inertial navigation reference surface (32) is a plane that fits against the side of the inertial navigation; At least two blind-fit docking guide rods (33) are fixed on the inertial navigation reference surface (32). One end of the blind-fit docking guide rod (33) is fixed on the inertial navigation reference surface (32), and its axis is perpendicular to the inertial navigation reference surface (32) and spans the corresponding opening. The blind mating assembly is located at each of the openings and includes a floating sub-plate (44), a micro-rectangular interface female (45), a blind mating guide pin (46), and a quick-locking structure (60). The floating sub-plate (44) has a guide through hole, the axis of which is parallel to the axis of the blind mating guide rod (33). The floating sub-plate (44) is fitted onto the blind mating guide rod (33) through the guide through hole and can slide along the blind mating guide rod (33). The diameter of the guide through hole is larger than the outer diameter of the blind mating guide rod (33). The micro-rectangular interface female (45) is fixed to the floating sub-plate (44). At least two blind-fit guide pins (46) are parallel to each other and located on both sides of the micro-rectangular interface female (45). The axis of the blind-fit guide pin (46) is parallel to the axis of the blind-fit guide rod (33). The extension length of the blind-fit guide pin (46) is greater than the extension length of the electrical pin inside the micro-rectangular interface female (45). The quick-locking structure (60) includes a pull rod (61) and a connecting rod (62). The pull rod (61) is hinged to the inertial navigation mounting tray (2). One end of the connecting rod (62) is hinged to the pull rod (61), and the other end is hinged to the floating subplate (44). Each layer of the inertial navigation mounting tray (2) is provided with at least one inertial navigation pressure strip (34), the two ends of the inertial navigation pressure strip (34) are respectively fixed on two crossbeams (31) of the same layer, and the inertial navigation pressure strip (34) is located above multiple inertial navigation mounting positions (41); Each layer of the inertial navigation mounting tray (2) is provided with at least one data acquisition board (51), and the data acquisition board (51) is provided with a microcontroller, a multi-channel serial port interface circuit, an Ethernet interface circuit and an inertial navigation power supply circuit; each of the micro rectangular interface females (45) on the same layer is connected to the serial port interface circuit and the inertial navigation power supply circuit respectively via an inertial navigation connection cable (53); each layer of the data acquisition board (51) is connected to the corresponding base interface (13) via an exit cable (52), and the exit cable (52) is provided with a power supply wire connected to the inertial navigation power supply circuit and an Ethernet signal wire connected to the Ethernet interface circuit.

2. The inertial navigation batch calibration and testing installation fixture according to claim 1, characterized in that, The side containing the two rounded corners of the same-side rounded rectangle is parallel to the inertial navigation reference surface (32), and the radius of the rounded corner is 3mm to 8mm.

3. The inertial navigation batch calibration and testing installation fixture according to claim 1, characterized in that, At least two preload springs (43) are connected between the floating subplate (44) and the inertial navigation mounting tray (2). The force of the preload springs (43) is parallel to the axis of the blind insertion guide pin (46) and points towards the opening.

4. The inertial navigation batch calibration and testing installation fixture according to claim 1, characterized in that, The quick-locking structure (60) further includes a fixed hinge (63) and two movable hinges (64); the pull rod (61) is a rigid rod integrally formed and is hinged to the inertial navigation mounting tray (2) via the fixed hinge (63); one end of the connecting rod (62) is hinged to the pull rod (61) via one of the movable hinges (64), and the other end of the connecting rod (62) is hinged to the floating subplate (44) via the other movable hinge (64); the rotational stroke of the pull rod (61) around the fixed hinge (63) crosses the position where the fixed hinge (63) and the two movable hinges (64) are collinear, forming an over-center self-locking mechanism.

5. The inertial navigation batch calibration and testing installation fixture according to claim 4, characterized in that, The connecting rod (62) is an elastic rod; when the pull rod (61) rotates to a position that crosses the collinearity of the center, it abuts against the inertial navigation reference surface (32).

6. The inertial navigation batch calibration and testing installation fixture according to claim 1, characterized in that, The front end of the blind insertion guide pin (46) is provided with a ball head section or a tapered inlet section.

7. The inertial navigation batch calibration and testing installation fixture according to claim 1, characterized in that, The fit clearance between the inertial navigation positioning pin (42) and the mounting hole on the bottom surface of the inertial navigation system is 0.1mm to 0.3mm; the difference between the diameter of the guide through hole and the outer diameter of the blind insertion guide rod (33) is 0.2mm to 0.8mm.

8. The inertial navigation batch calibration and testing installation fixture according to claim 1, characterized in that, The inertial navigation mounting tray (2) is provided with multiple cable routing holes (47) that run through its front and back sides, and a cable clamp (48) is provided on the back side; the inertial navigation connecting cable (53) runs from the front to the back side through the cable routing holes (47) and is clamped by the cable clamp (48); the data acquisition board (51) is fixed to the back side of the inertial navigation mounting tray (2).

9. The inertial navigation batch calibration and testing installation fixture according to claim 1, characterized in that, The inertial navigation installation tray (2) is provided with tray handles (23) on its opposite sides.

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