CN220625325U - IMU of inside vibration isolation - Google Patents

Abstract

The utility model relates to the technical field of strapdown inertial navigation, and provides an IMU with internal vibration isolation, which comprises a sensitive device, a flange and a shell, wherein the sensitive device is arranged on the flange, the flange is also provided with a vibration isolator for filtering vibration, the shell is provided with a concave cavity for the flange to be installed in, a gap is reserved between the flange and the inner wall of the shell, and a bottom plate for packaging the flange in the concave cavity is arranged on the shell. The utility model adopts a single flange design, ensures the vibration isolation performance while ensuring the integral rigidity, and synchronously vibrates each sensitive device (gyroscope and accelerometer), and simultaneously the flange and the shell are placed at a space position for hovering and avoiding. In the working process of the vibration isolator, the flange and devices on the flange cannot strike the inner wall of the shell, and normal working of the vibration isolator is guaranteed.

Description

IMU of inside vibration isolation

Technical Field

The utility model relates to the technical field of strapdown inertial navigation, in particular to an IMU with internal vibration isolation.

Background

Because the IMU adopts the MEMS gyroscope and the accelerometer, the volume and the cost of the IMU are greatly reduced, and the zero offset stability precision can be kept between 10 degrees/h and 100 degrees/h. The method is widely applied to the fields of unmanned aerial vehicles, missile guidance, unmanned aerial vehicles and the like. With the continuous penetration of unmanned fields and the like, the demand for high-precision IMU devices is also increasing.

In high precision IMUs, the main sources of systematic errors are: structural installation errors, uneven temperature, overhigh temperature, vibration and other factors. The vibration isolation requirements of the prior art on mes are not high, mainly by welding sensitive devices (gyroscopes and accelerometers) to a single plate, and the single plate is fixed on a workpiece. The relative position accuracy and vibration isolation performance of sensitive devices (gyroscopes and accelerometers) are poor. The sensitive device generates two position errors, namely, the relative position error of the sensitive device (gyroscope and accelerometer) and the PCB is generated by welding; and the other is a position error generated by the installation of the PCB and the structural part. In the working state, when vibration occurs, the PCB board adopts a multi-point fixed form and is easy to deform, so that the relative positions of sensitive devices (gyroscopes and accelerometers) are changed, and noise is introduced. The sensitive devices are in a suspension mode, so that the thermal stability among the devices is poor; and has an increased temperature difference.

Disclosure of Invention

The utility model aims to provide an IMU with internal vibration isolation, which can at least solve part of defects in the prior art.

In order to achieve the above object, the embodiment of the present utility model provides the following technical solutions: the utility model provides an IMU of inside vibration isolation, includes sensitive device, flange and shell, sensitive device locates on the flange, still install the isolator that is used for filtering vibration on the flange, the shell has the confession the concave cavity that the flange was packed into, just the flange with have the clearance between the inner wall of shell, install on the shell be used for with the flange encapsulation is in the bottom plate in the concave cavity.

Further, the vibration isolators are arranged in a plurality, and the vibration isolators are arranged at four corners of the flange.

Further, the sensitive device is fixed on the flange through a limiting structure.

Further, circuit boards electrically connected with the sensitive devices are arranged on a plurality of surfaces of the flange.

Further, the circuit board is locked on the flange through screws.

Further, the sensing device contacts the metal outer wall of the flange.

Further, the vibration isolator comprises a fixed shaft arranged on the flange and a buffer structure sleeved on the fixed shaft.

Further, the cushioning structure comprises rubber or springs.

Further, the fixed shaft extends in a direction consistent with a direction in which the base plate is fitted to the housing.

Further, the sensitive device comprises a gyroscope and/or an accelerometer.

Compared with the prior art, the utility model has the beneficial effects that:

1. the design of a single flange is adopted, the vibration isolation performance is ensured while the integral rigidity is ensured, and all sensitive devices (gyroscopes and accelerometers) vibrate synchronously, and meanwhile, the flange and the shell are placed at a space position where hovering and avoiding are adopted. In the working process of the vibration isolator, the flange and devices on the flange cannot strike the inner wall of the shell, and normal working of the vibration isolator is guaranteed.

2. The vibration direction, the vibration phase and the vibration intensity of each shaft are unified through the integrated vibration isolator, damping is weakened through the vibration isolator, and the error accumulation and the later calibration difficulty caused by the vibration direction, the vibration phase and the vibration intensity of devices which are not caused in the same vibration isolation system are reduced.

3. Each shaft is fixed on the same flange, parallelism and perpendicularity among the shafts are easier to be ensured, relative positions among the shafts are fixed, cross errors are reduced, and zero offset stability of the IMU is ensured.

4. The back of the sensitive device (gyroscope and accelerometer) is contacted with the metal surface of the flange for heat dissipation, and then the vibration isolator is uniformly installed through the flange and fixed in the shell, so that the heat dissipation capacity is improved, the temperature difference of each device is reduced, and the temperature compensation is facilitated.

5. The relative position accuracy of the sensitive devices (gyroscopes and accelerometers) is guaranteed through the direct contact limit of the sensitive devices (gyroscopes and accelerometers) and the structural members, and the accumulated errors (position errors generated during installation and welding) are reduced.

6. The deformation caused by the vibration of the large plate (large-size plate) is reduced by combining a plurality of small plates (small PCB plates) on the structural member, and the small plates are introduced into sensitive devices (gyroscopes and accelerometers).

7. The PCB is fixed in a mode of contacting all around and fixing by screws, so that the deformation of the PCB is further reduced.

Drawings

FIG. 1 is a schematic diagram of an IMU batch calibration device provided by an embodiment of the present utility model;

fig. 2 is a schematic view of a first view angle of a multi-layer calibration board and a second electrical switching circuit board of an IMU batch calibration apparatus according to an embodiment of the utility model;

fig. 3 is a schematic diagram of a second view angle of cooperation between a multi-layer calibration board and a second electrical switching circuit board of an IMU batch calibration apparatus according to an embodiment of the utility model;

FIG. 4 is a schematic diagram of a locking assembly of an IMU batch calibration device in cooperation with a calibration box according to an embodiment of the present utility model;

fig. 5 is a schematic diagram showing cooperation of a data end, a second electrical switching circuit board and a reinforcing structural member in a top view of an IMU batch calibration apparatus according to an embodiment of the utility model;

fig. 6 is a schematic diagram of a first view angle of a plurality of IMUs disposed on a calibration board of an IMU batch calibration apparatus according to an embodiment of the utility model;

FIG. 7 is a schematic diagram of the top view of FIG. 6;

fig. 8 is a schematic diagram of a second view angle of a plurality of IMUs disposed on a calibration board of an IMU batch calibration apparatus according to an embodiment of the utility model;

FIG. 9 is a schematic diagram of the second locating pin, pin hole and spring engagement of the locking assembly of an IMU batch calibration apparatus in accordance with an embodiment of the present utility model;

fig. 10 is a schematic diagram of an IMU with internal vibration isolation according to an embodiment of the present utility model;

fig. 11 is an exploded view of an IMU with internal vibration isolation according to an embodiment of the utility model;

FIG. 12 is a schematic illustration of an IMU with the housing and base plate removed for internal vibration isolation in accordance with embodiments of the present utility model;

FIG. 13 is an exploded view of FIG. 12;

FIG. 14 is a partial schematic view of the structure of FIG. 12;

FIG. 15 is a partial schematic view of the structure of FIG. 12;

FIG. 16 is an enlarged schematic view at A of FIG. 14;

in the reference numerals:

1-IMU; 10-a first electrical connector port; 11-gyroscopes; 12-an accelerometer; 13-flanges; 14-a housing; 140-concave chambers; 15-a bottom plate; 16-vibration isolator; 160-a fixed shaft; 161-buffer structure; 170-upper layer circuit board; 171-middle layer circuit board; 172-lower layer circuit board; 173-left side circuit board; 174-right side circuit board; 175—front side circuit board;

2-IMU batch calibration device; 20-calibrating a plate; 200-data terminal; 201-a first electrical switching circuit board; 2010-a second electrical connector port; 2011-a fourth electrical connector port; 202-a handle; 21-a calibration box; 22-a second electrical switching circuit board; 221-a third electrical connector port; 222-output interface; 23-reinforcing the structural member; 240-a first locating pin; 241-first positioning holes; 242-second locating pins; 243-a second positioning hole; 244-pin holes; 245-a spring; 25-screws.

Detailed Description

The following description of the embodiments of the present utility model will be made clearly and completely with reference to the accompanying drawings, in which it is apparent that the embodiments described are only some embodiments of the present utility model, but not all embodiments. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

Referring to fig. 1, 2 and 3, an IMU batch calibration apparatus is provided in an embodiment of the present utility model, which includes a plurality of calibration boards 20 and a calibration box 21 in which the calibration boards 20 are disposed, each calibration board 20 includes a first electrical switching circuit board 201 having a plurality of mounting positions for mounting IMUs, a data terminal 200 for collecting data of IMUs on each of the mounting positions, and a data terminal 200 for sending the data of IMUs to an external test module. Through the design can install the calibration board 20 of a plurality of IMUs and design can assemble the data end 200 of all IMU data, can carry out batch test with the data output of each IMU to external test module, realize the batch parameter calibration of IMU, and can be convenient for take out when meetting unusual equipment through the mode that calibration board 20 can insert or take out calibration case 21, can realize quick installation again can realize quick dismantlement. The IMU is an inertial measurement unit, and may include a gyroscope and/or an accelerometer. In the prior art, the parameter calibration is mostly carried out on the device, and the efficiency is extremely low. The calibration board 20 is adopted in the embodiment, the mounting position can be preset on the board body according to the requirement, the IMU can be mounted on the mounting position, the arrangement mode of the IMU is determined according to the position of the mounting position, for example, the structural form of the square matrix shown in the embodiment can be designed, other forms such as an annular array or irregular shapes can be designed according to the requirement, the data of each IMU can be collected to the data end 200 only through the first electric switching circuit board 201, the data end 200 is a total data end, and multiple groups of data can be output to an external test, so that the number of single test is increased, the direct independence of equipment is improved, the equipment mounting difficulty is reduced, the operation time and labor of the equipment are reduced, and the calibration efficiency can be greatly improved. And because the calibration plate 20 is convenient to insert or withdraw the calibration box 21, the assembly and disassembly are convenient, and the disassembly and the assembly are convenient when the equipment is abnormal. In addition, the mounting position of the IMU also needs to be positioned, the positioning in the first direction can be realized through the vertical baffle plate at the mounting position, and then the groove can be arranged at the mounting position, so that the IMU is positioned in the other two directions. The first electrical switching circuit board 201 may define a second electrical connector port 2010 and a fourth electrical connector port 2011, and the second electrical switching circuit board 22, which is detailed in the following embodiments, may define a third electrical connector port 221, which is further detailed in the following embodiments.

With further refinement of the batch calibration scheme, referring to fig. 1, 2 and 3, a plurality of calibration plates 20 may be designed, and accordingly, the size of the calibration box 21 may be increased according to the design, and the calibration box 21 further includes a guide slot for each of the calibration plates 20 to be inserted into or withdrawn from, and the internal guide slot is configured according to the number of the calibration plates 20, so that parameter calibration of a greater number of IMUs may be extended. Specifically, the laminated form shown in the present embodiment may be adopted, so that the worker can easily pull the calibration plate 20. Other arrangements are also possible, as long as a plurality of calibration plates 20 can be accommodated, which is not limited in this embodiment.

Referring to fig. 1, 2, 3, 6 and 7, the apparatus further includes a second electrical switching circuit board 22 for interfacing with an external test module, and the data end 200 of each calibration board 20 is connected to the second electrical switching circuit board 22. After the calibration boards 20 are provided, there are a plurality of data terminals 200, and in order to facilitate docking with an external test terminal, the second electrical switching circuit board 22 may be designed to electrically connect the data terminals 200, so that the data collected by the calibration boards 20 to the data terminals 200 may be collected again and output by the second electrical switching circuit board 22. In the form of a plurality of calibration boards 20 stacked in this embodiment, the second electrical switching circuit board 22 may be a riser, and preferably, each data terminal 200 is located at the same position of the calibration board 20, so that a long riser is designed to connect each data terminal 200. Preferably, the first electrical switching circuit board 201 may be configured in multiple pieces, the number of which may be determined based on the number of IMUs. As shown in the three rows of IMUs of the present embodiment, three first electrical switching circuit boards 201 may be disposed correspondingly. Each IMU has a first electrical connector port and each first electrical switching circuit board 201 has a plurality of second electrical connector ports 2010, the number of second electrical connector ports 2010 being the same as the number of IMUs of each row of IMUs, each first electrical connector port 10 being electrically connected to its corresponding second electrical connector port 2010. The plurality of second electrical connector ports 2010 on each first electrical switching circuit board 201 collect signals to the fourth electrical connector port 2011, and the fourth electrical connector port 2011 inputs data to the third electrical connector port 221, so that the plurality of third electrical connectors on the second electrical switching circuit board 22 can collect data of all IMUs to the data terminal 200.

Referring to fig. 4, 8 and 9, the device further comprises a locking assembly for locking and positioning each of the calibration plates 20 within the calibration box 21. In this embodiment, in order to ensure that the calibration plate 20 is inserted into the calibration box 21 to be positioned accurately, the locking assembly may be designed to complete positioning, so that the alignment accuracy is higher, the later stage is convenient to cooperate with the three-axis turntable, and the tolerance of the relative position is small. And simultaneously, the locking function can be realized, and the calibration plate 20 is prevented from being freely separated from the calibration box 21.

For further details of the above locking assembly, please refer to fig. 4, 8 and 9, the locking assembly includes a first positioning pin 240 disposed on each calibration plate 20, a first positioning hole 241 for inserting the first positioning pin 240 is disposed in the calibration box 21, and a depth direction of the first positioning hole 241 is consistent with a moving direction of the calibration plate 20. The first form of locking is locking in the Y direction of the present embodiment, that is, the first positioning pin 240 is designed on the calibration plate 20, the first positioning hole 241 corresponding to the first positioning pin 240 is provided in the calibration box 21, and after the position is adjusted, the calibration plate 20 is inserted into the calibration box 21 to complete the positioning. The locating pin and the locating hole can be designed into a clamping mode, so that a certain locking effect can be achieved.

For further details of the above locking assembly, referring to fig. 4, 8 and 9, the locking assembly includes second positioning pins 242, each of the calibration plates 20 is provided with a pin hole 244 in which the second positioning pin 242 slides, the calibration box 21 has a second positioning hole 243 into which the second positioning pin 242 is inserted, and the depth direction of the second positioning hole 243 is perpendicular to the moving direction of the calibration plate 20. The second form of locking is in the X-direction of the present embodiment so that positioning is accomplished in both the X-direction and Y-direction, and in the Z-direction, locking is accomplished by virtue of the mating of the indexing plate 20 with the guide slot. The locking in the X direction can also be realized by matching the positioning pin with the positioning hole with the Y-direction locking, and the extending directions of the positioning pin are different. Of course, the positioning pin can extend in the Z direction, and the locking effect can be realized. Preferably, the locking assembly further comprises a spring 245 for urging the second positioning pin 242 into the second positioning hole 243, the second positioning pin 242 being mounted on the spring 245. The spring 245 may be designed to effect the return. Of course, the second positioning pin 242 and the second positioning hole 243 can be designed at the insertion opening of the calibration box 21, so that manual locking is possible.

Referring to fig. 3 and 5, a reinforcing structure 23 is disposed on a side of the second electrical switching circuit board 22 facing away from the data terminal 200. The second electric switching circuit board 22 is provided with a reinforcing structural member 23, the reinforcing structural member 23 and the second electric switching circuit board are fixed through screws 25, and the reinforcing structural member 23 is convenient to fixedly mount with external equipment. The signal output interface 222 of the second electrical switching circuit board 22 may be provided on the reinforcing structure 23 to facilitate connection with external equipment.

Referring to fig. 7, a handle 202 is disposed on each calibration plate 20. The handle 202 is provided to facilitate the operator to push or pull the calibration plate 20.

The embodiment of the utility model provides an IMU batch test system, which comprises a three-axis turntable and the IMU batch calibration device 2, wherein the IMU batch calibration device is fixed on the three-axis turntable. The device described above may be fixed to the three-axis table, mainly with two perpendicular intersecting surfaces of the three-axis table. The calibration can be completed in the triaxial belt temperature control turntable. Due to the adoption of the device, on one hand, batch calibration can be realized, and on the other hand, due to the fact that the device is accurate in positioning, the three-axis turntable reference can be guaranteed to be transmitted to each IMU 1 through an internal structure, and therefore the accuracy of the whole system is controllable.

Referring to fig. 10 to 16, an embodiment of the present utility model provides an IMU (inertial measurement unit) with internal vibration isolation, which can be tested in batch by the IMU batch test system. The IMU comprises a sensitive device, a flange 13 and a shell 14, wherein the sensitive device is arranged on the flange 13, a vibration isolator 16 for filtering vibration is further arranged on the flange 13, the shell 14 is provided with a concave cavity 140 in which the flange 13 is arranged, a gap is reserved between the flange 13 and the inner wall of the shell 14, and a bottom plate 15 for packaging the flange 13 in the concave cavity is arranged on the shell 14. In the embodiment, a single flange 13 is adopted to ensure the integral rigidity and vibration isolation performance, and each sensitive device vibrates synchronously, and meanwhile, a gap is reserved between the flange 13 and the inner wall of the shell 14, and the space position of hovering and avoiding is adopted for placement. The flange 13 and devices on the flange 13 are prevented from striking the inner wall of the shell 14 in the working process of the vibration isolator 16, and the normal working of the vibration isolator 16 is ensured. Specifically, as shown in fig. 11, the IMU has a monolithic structure, in which the intermediate devices are all mounted on a single flange 13, and then the flange 13 is integrally mounted in a housing 14 having a concave cavity 140, and then a bottom plate 15 is covered on the housing 14. The vibration isolator 16 can ensure good vibration isolation effect while ensuring integral rigidity due to compact integral structure, the flange 13 is not contacted with the inner wall of the shell 14, devices on the flange 13 and the flange 13 can be prevented from striking the inner wall of the shell 14, and normal operation of the vibration isolator 16 is ensured. The vibration isolator 16 used herein can filter out low-frequency vibration and high-frequency vibration generated during operation.

With the above flange 13 in detail, referring to fig. 12 to 16, there are a plurality of vibration isolators 16, the flange 13 is square, and the vibration isolators 16 are disposed at four corners of the flange 13. The flange 13 may be a common square flange 13, so that four vibration isolators 16 are preferably arranged, and one vibration isolator 16 is arranged at each of four corners of the flange 13, so that a balanced vibration isolation effect can be achieved. The vibration directions, the vibration phases and the vibration intensities of the shafts are unified through the integrated vibration isolator 16, damping is weakened through the vibration isolator 16, and the error accumulation and the later calibration difficulty caused by the vibration directions, the vibration phases and the vibration intensities of devices which are not in the same vibration isolation system are reduced. The shafts are fixed on the same flange 13, the parallelism and the perpendicularity between the shafts are easier to ensure, the relative positions between the shafts are fixed, and the cross error is reduced. The zero offset stability of the IMU is ensured.

Referring to fig. 14 and 16, the sensing device is fixed on the flange 13 through a limiting structure. In the embodiment, the sensing devices (the gyroscope 11 and the accelerometer 12) are in direct contact with the structural parts for limiting, so that the relative position accuracy of the sensing devices (the gyroscope 11 and the accelerometer 12) is guaranteed, and accumulated errors (position errors generated during installation and welding) are reduced. Specifically, the limiting structure may be a groove thinned on the flange 13 for the sensitive device to be clamped in, or may be a designed step, and is a feasible limiting mode in combination with the clamping of a circuit board.

Referring to fig. 13, circuit boards capable of electrically connecting with the sensitive devices are disposed on multiple surfaces of the flange 13. In the present embodiment, the design form of the plurality of circuit boards (small circuit boards) can reduce the deformation caused by the vibration of the large board (large-size board) and is introduced into the sensitive devices (gyroscope 11, accelerometer 12). Specifically, the circuit boards may be defined as an upper circuit board 170, a middle circuit board 171, a lower circuit board 172, a left circuit board 173, a right circuit board 174, and a front circuit board 175 according to their positions, wherein the upper circuit board 170 covers the upper surface of the flange 13, and covers the gyroscope 11 in a groove on the upper surface of the flange 13. The middle circuit board 171 and the lower circuit board 172 are both located below the flange 13, the middle circuit board 171 covers the accelerometer 12, and the lower circuit board 172 covers the middle circuit board 171. While the left side circuit board 173, the right side circuit board 174, and the front side circuit board 175 are provided on three sides of the flange 13, respectively. The circuit boards can be locked on the flange 13 through screws, the PCB is fixed in a mode of surface peripheral contact and screw fixation, and the deformation of the PCB is further reduced.

Referring to fig. 14 to 16, the sensing device contacts the metal outer wall of the flange 13. The back of the sensitive device (gyroscope 11, accelerometer 12) is contacted with the metal surface of the flange 13 to dissipate heat, and then the vibration isolator 16 is uniformly arranged through the flange 13 and fixed in the shell 14, so that the heat dissipation capacity is improved, the temperature difference of each device is reduced, and the temperature compensation is facilitated.

With reference to fig. 11 to 13, the vibration isolator 16 includes a fixed shaft 160 mounted on the flange 13 and a buffer structure 161 provided on the fixed shaft 160. The buffer structure 161 comprises rubber or a spring, and the rubber or the spring is sleeved on the fixed shaft 160. In this embodiment, the vibration isolator 16 may be thinned into a fixed shaft 160 mounted on the flange 13, and the fixed shaft 160 is wrapped with a buffer structure 161, so as to perform a vibration isolation effect. The buffer structure 161 may be made of rubber, a spring, or the like, which is not limited in this embodiment.

The mounting position of the vibration isolator 16 is further refined, and the direction in which the fixed shaft 160 extends coincides with the direction in which the base plate 15 is fitted to the housing 14. As shown in fig. 11, the fixed shaft 160 is vertically disposed with a length direction or extending direction in accordance with a direction in which the base plate 15 is attached to the housing 14.

Referring to fig. 14 and 15, the sensing device includes a gyroscope 11 and/or an accelerometer 12, and the gyroscope 11 and/or the accelerometer 12 are/is mounted on the flange 13. The sensing devices in this embodiment may be a gyroscope 11 and an accelerometer 12, which are fixed to the flange 13 in a manner of structural limitation according to the respective sensing axis directions.

Although embodiments of the present utility model have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can be made therein without departing from the principles and spirit of the utility model, the scope of which is defined in the appended claims and their equivalents.

Claims (10)

1. An IMU with internal vibration isolation, characterized in that: the vibration isolator comprises a sensitive device, a flange and a shell, wherein the sensitive device is arranged on the flange, the flange is further provided with a vibration isolator for filtering vibration, the shell is provided with a concave cavity for the flange to be installed in, a gap is reserved between the flange and the inner wall of the shell, and the shell is provided with a bottom plate for packaging the flange in the concave cavity.

2. The IMU of claim 1, wherein: the vibration isolators are arranged in a plurality of mode and are arranged at four corners of the flange.

3. The IMU of claim 1, wherein: the sensitive device is fixed on the flange through a limiting structure.

4. The IMU of claim 1, wherein: and a plurality of surfaces of the flange are respectively provided with a circuit board electrically connected with the sensitive device.

5. The IMU of claim 4, wherein: the circuit board is locked on the flange through screws.

6. The IMU of claim 1, wherein: the sensing device contacts the metal outer wall of the flange.

7. The IMU of claim 1, wherein: the vibration isolator comprises a fixed shaft arranged on the flange and a buffer structure sleeved on the fixed shaft.

8. The IMU of claim 7, wherein: the cushioning structure comprises rubber or springs.

9. The IMU of claim 7, wherein: the fixed shaft extends in a direction consistent with a direction in which the base plate is assembled to the housing.

10. The IMU of claim 1, wherein: the sensitive device comprises a gyroscope and/or an accelerometer.