High-overload-resistant MEMS high-precision inertial measurement unit

Abstract

The invention discloses a high-overload-resistant MEMS (Micro Electro Mechanical System) high-precision inertial measurement unit, which is mainly used for inertial measurement and attitude and position output of a carrier under high-overload and large-impact conditions, can adapt to a high-overload application environment and can meet the inertial measurement precision requirement under a high-dynamic condition at the same time. Three single-axis MEMS gyroscopes and three single-axis MEMS accelerometers are combined to form a three-axis orthogonal inertial measurement circuit, and the three-axis orthogonal inertial measurement circuit is matched with a small ARM processor to carry out data acquisition and information calculation and output carrier attitude and position information to the outside. A small full-balance multi-node shock isolation and absorption system is designed, the mechanical vibration noise of the system is optimized, and the high-overload and high-dynamic mechanical environment adaptability of the inertial measurement unit is improved. The system is small and light in design, high in attitude measurement precision and low in hardware power consumption and cost, adopts a national standard universal interface, has relatively high environmental adaptability and system stability, and has certain system expansion capability and great popularization and application space and market prospect.

Description

Technical Field

[0001] The present invention belongs to the technical field of inertial navigation, and in particular relates to a high-overload resistant MEMS high-precision inertial measurement unit. Background Art

[0002] A wide variety of inertial measurement products are emerging on the market, and the vast majority are based on inertial components from major foreign manufacturers, such as ADI's ADXRS642 and Colibrys' MS9110. Mature domestically produced inertial components are few and far between, and those few that exist suffer from large size, poor reliability, and large errors, particularly in high-overload, high-shock, and high-dynamic environments, making them difficult to meet technical specifications.

[0003] Since MEMS inertial navigation belongs to the integral incremental measurement type, the transient measurement errors of angular velocity and acceleration will cause the errors of the integrated angle or velocity to accumulate over time. Therefore, the accuracy of the transient measurement determines the actual accuracy index of the MEMS inertial navigation. In addition, unlike traditional fiber optic and laser-type inertial measurement equipment, MEMS inertial devices have certain principle design characteristics. The stability of the vibration state of their internal oscillators plays a decisive role in the accuracy of their detection frequency. When the MEMS oscillator encounters external shocks and vibrations while resonating, it will cause slight changes in the oscillator swing and frequency, resulting in error values ​​in transient measurements, and ultimately causing errors in the integrated angle and velocity, affecting the overall accuracy index of the MEMS inertial navigation. Finally, shocks of tens of thousands of g will directly damage the internal microstructure of the inertial device, placing high demands on the overload resistance design of the inertial measurement product. Therefore, a well-designed shock absorption and buffering system is a necessary condition for MEMS inertial navigation.

[0004] Furthermore, while the relative accuracy and cost of MEMS inertial navigation systems are lower than those of fiber optic and laser inertial navigation systems, the requirements for miniaturization and low power consumption are relatively high. The layout design and electromagnetic compatibility design of high-precision MEMS inertial devices within a small space are relatively difficult. Foreign components, due to their relatively mature packaging processes and relatively high component efficiency, have relatively low system requirements for layout size and electromagnetic compatibility. Developing products in confined spaces according to conventional design process requirements can generally meet hardware stability requirements. However, the manufacturing level of domestically produced components needs to be improved, placing even higher system requirements on product design.

[0005] Therefore, designing a MEMS high-precision inertial navigation system that meets the requirements of large impact, high overload, high dynamics, miniaturization and low power consumption has become an urgent need in the current military market. Summary of the Invention

[0006] In order to overcome the shortcomings of the existing technology, the present invention provides a high-overload resistant MEMS high-precision inertial measurement unit, which is mainly used for carrier inertial measurement and attitude and position output under high overload and large impact conditions. It can adapt to high overload application environments while meeting the inertial measurement accuracy requirements under high dynamic conditions. The present invention mainly utilizes three single-axis MEMS gyroscopes and three single-axis MEMS accelerometers to form a three-axis orthogonal inertial measurement circuit, cooperates with a small ARM processor to perform data acquisition and information solution, and outputs the carrier attitude and position information to the outside. In view of the mechanical adaptability characteristics and core quality characteristics of MEMS inertial devices, a small fully balanced multi-node shock isolation and damping system is specially designed and developed to optimize the system mechanical vibration and noise, and improve the high overload and high dynamic mechanical environment adaptability of the inertial measurement unit. The present invention is compact and lightweight, with high attitude measurement accuracy, low hardware power consumption and cost, and uses a national standard universal interface. It has strong environmental adaptability and system stability, a certain system expansion capability, and great promotion and application space and market prospects.

[0007] The technical solutions adopted by the present invention to solve the technical problems are as follows:

[0008] A high-overload resistant MEMS high-precision inertial measurement unit, comprising an inertial measurement circuit, structural components, and shock isolation and damping components;

[0009] The inertial measurement circuit is installed on the outer surface of the structural member, and relies on the six orthogonal outer surfaces of the structural member to achieve load bearing and protection, forming an inertial measurement assembly; after the inertial measurement assembly and the shock isolation and damping assembly are assembled, it is installed on the base of the structural member;

[0010] The inertial measurement circuit adopts an integrated design. Three internal single-axis accelerometers and three single-axis gyroscopes respectively realize sensitive measurement of acceleration and angular velocity, which are converted into standard digital quantities and sent to the ARM processor via the SPI interface. The ARM processor uses the currently collected inertial information to calculate the current carrier's attitude, speed, and position information through a navigation solution model, and interacts with the outside world through a standard communication interface.

[0011] Preferably, the inertial measurement circuit utilizes a flexible circuit to distribute the mass of the entire hardware circuit onto six pairwise orthogonal surfaces.

[0012] Preferably, the inertial measurement unit adopts a fully balanced multi-node design, using special asymmetric stiffness and size to offset the impact of launch shock on inertial devices.

[0013] Preferably, the shock isolation and damping assembly adopts a T-shaped rubber shock-absorbing pad design, which forms a small multi-node shock isolation and damping system after being assembled with the core bracket of the structural member.

[0014] Preferably, the inertial measurement circuit is composed of 6 connected circuits, which are made of flexible PCB technology and can be bent and folded, and are directly assembled and fixed to the six mounting surfaces of the structural component by M2 screws.

[0015] Preferably, the shock isolation and damping assembly is installed in the flanges around the structural member, a T-shaped thick pad is installed at the lower end, a T-shaped thin pad is installed at the upper end, and the limiting sleeve passes through the T-shaped pad.

[0016] The beneficial effects of the present invention are as follows:

[0017] 1) The high-overload resistant MEMS high-precision inertial measurement unit adopts an integrated hardware design, and is equipped with a fully balanced multi-node shock absorption system. This can achieve many advantages such as lightweight, small size, high precision, and low power consumption. It has high process accessibility, high product consistency, and reduces product hard costs.

[0018] 2) The product utilizes a standard interface design and universal manufacturing process, enabling software and hardware expansion and upgrade capabilities. This integrated hardware system significantly reduces hardware and human resource costs, shortens the R&D and manufacturing cycles of intelligent ammunition weapon systems, and fosters a trend toward modularization and standardization. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 This is a diagram showing the composition of the high-overload resistant MEMS high-precision inertial measurement unit of the present invention;

[0020] Figure 2 This is a schematic diagram of the inertial measurement circuit system framework of the present invention;

[0021] Figure 3 This is the external dimension diagram of the high-overload resistant MEMS high-precision inertial measurement unit of the present invention.

[0022] Reference numerals: inertial measurement circuit 1 , structural component 2 , shock isolation and damping assembly 3 . DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings and examples.

[0024] The purpose of this invention is to propose a high-overload-resistant MEMS high-precision inertial measurement unit for use in large-shock, high-overload, and high-dynamic application environments in light of development trends, so as to solve the problems of MEMS inertial guidance in terms of stability, adaptability, miniaturization, high precision, and low cost in large-shock, high-overload, and high-dynamic environments, and achieve the practical engineering goal of reducing costs and increasing efficiency.

[0025] To solve the above problems, the present invention is completed by the following technical solutions.

[0026] 1. The device of the present invention is composed of Figure 1Shown: inertial measurement circuit 1, structural component 2 and shock isolation and damping assembly 3.

[0027] 2. The implementation principle of this device is as follows Figure 2 As shown, the inertial measurement circuit 1 utilizes an integrated design. Three internal uniaxial accelerometers and three uniaxial gyroscopes provide sensitive acceleration and angular velocity measurements, respectively. These signals are converted into standard digital quantities and transmitted to the ARM processor via an SPI interface. The ARM processor uses this collected inertial information to calculate the vehicle's attitude, velocity, and position using a navigation solution model, communicating with the outside world via a standard communication interface. The design of the inertial measurement circuit 1 utilizes flexible circuits to distribute the entire hardware circuit mass onto six orthogonal surfaces. The design considers the effects of component heat generation and electromagnetic radiation, utilizing a comprehensive three-dimensional spatial design. The spatial placement of heat-generating components is then rationally adjusted to minimize the impact of thermal radiation on the MEMS inertial components.

[0028] 3. Such as Figure 3 As shown, in this device, the inertial measurement circuit 1, structural component 2 and shock isolation and damping component 3 are assembled to form a high-overload resistant MEMS high-precision inertial measurement unit. This inertial measurement unit adopts a fully balanced multi-node design, using special asymmetric stiffness and size to offset the impact of launch shock on inertial devices. Lightweight, small size, high process accessibility, and high product consistency are the biggest highlights of this design. The center of mass of the fully balanced core is centered, which can effectively reduce the impact of the lever arm effect generated by movement on inertial measurement, which is beneficial to improving measurement accuracy. The fully balanced multi-node damping method significantly reduces the performance requirements of a single shock pad, effectively avoiding the impact of vibration and shock on the measurement accuracy of inertial devices, and greatly improving the measurement accuracy of the system.

[0029] Example:

[0030] like Figure 3 As shown, in the first step, the inertial measurement circuit 1 of the present invention consists of six interconnected circuits. These circuits utilize flexible PCB technology, allowing for bendability and folding. These circuits are then directly assembled and secured to the six mounting surfaces of the structural member 2 using M2 screws. In the second step, after installation, the shock isolation and damping assembly 3 is mounted within the flanges surrounding the structural member 2. A thick T-shaped pad is installed at the lower end, and a thin T-shaped pad is installed at the upper end. A limiting sleeve is then inserted through the T-shaped pads to complete the quick assembly.

[0031] The inertial measurement circuit 1 consists of a single circuit. To accommodate the compact space, it is divided into multiple sections, each connected via a flexible PCB. When assembled with the structural component 2, this enables inertial quadrature measurement and signal transmission. With the shock isolation and damping assembly 3, the high-overload-resistant MEMS high-precision inertial measurement unit can be installed within any structural housing, becoming its internal component. Featuring a compact size, low power consumption, and direct output of attitude and position information, it possesses broad market prospects and application needs.

Claims

1. A high-overload resistant MEMS high-precision inertial measurement unit, characterized in that: Including inertial measurement circuits, structural parts and shock isolation components; The inertial measurement circuit is installed on the facade of the structural member, and relies on the six orthogonal facades of the structural member to achieve load bearing and protection, forming an inertial measurement assembly; after the inertial measurement assembly and the shock isolation and damping assembly are assembled, it is installed on the base of the structural member; The inertial measurement circuit adopts an integrated design. Three internal single-axis accelerometers and three single-axis gyroscopes respectively realize sensitive measurement of acceleration and angular velocity, which are converted into standard digital quantities and sent to the ARM processor via the SPI interface. The ARM processor uses the currently collected inertial information to calculate the current carrier's attitude, speed, and position information through a navigation solution model, and interacts with the outside world through a standard communication interface.

2. The high-overload resistant MEMS high-precision inertial measurement unit according to claim 1, characterized in that: The inertial measurement circuit utilizes a flexible circuit to distribute the mass of the entire hardware circuit onto six pairs of orthogonal surfaces.

3. The high-overload resistant MEMS high-precision inertial measurement unit according to claim 1, characterized in that: The inertial measurement unit adopts a fully balanced multi-node design and uses special asymmetric stiffness and size to offset the impact of launch shock on inertial devices.

4. The high-overload resistant MEMS high-precision inertial measurement unit according to claim 1, characterized in that: The shock isolation and vibration reduction assembly adopts a T-shaped rubber vibration reduction pad design, and forms a small multi-node shock isolation and vibration reduction system after being assembled with the core bracket of the structural component.

5. The high-overload resistant MEMS high-precision inertial measurement unit according to claim 1, characterized in that: The inertial measurement circuit is composed of 6 connected circuits. The circuits adopt flexible PCB technology, can be bent and folded, and are directly assembled and fixed to the six mounting surfaces of the structural parts through M2 screws.

6. The high-overload resistant MEMS high-precision inertial measurement unit according to claim 1, characterized in that: The shock isolation and damping assembly is installed in the flanges around the structural member, with a T-shaped thick pad installed at the lower end and a T-shaped thin pad installed at the upper end, and a limiting sleeve passes through the T-shaped pad.

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