CN-122015813-A - Redundant inertial measurement unit and method based on heterogeneous system

CN122015813ACN 122015813 ACN122015813 ACN 122015813ACN-122015813-A

Abstract

The invention relates to a redundant inertial measurement unit based on a heterogeneous system, which is mainly used for solving the problems that signals are easy to cross talk and difficult to disassemble and assemble in the existing inertial measurement unit based on an MEMS gyroscope and an MEMS accelerometer, and the existing inertial measurement unit using a single optical fiber gyroscope or a laser gyroscope and a quartz flexible accelerometer has poor portability and integration. The invention comprises 3N quartz flexible accelerometers, MEMS modules, a power supply module, a host module and a signal resolving module. 3N quartz flexible accelerometers are added on the basis of the MEMS module to serve as redundant designs, so that the integrity of data collected by the accelerometers of the redundant inertial measurement unit in the using process is ensured, the reliability of the system is greatly improved, and the failure rate of the system is reduced.

Inventors

ZHOU JINGKE
XU BINGHUA
LI FENG
XIE BO
YANG YANG

Assignees

西安航天精密机电研究所

Dates

Publication Date: 20260512
Application Date: 20241112

Claims (6)

1. A redundant inertial measurement unit based on a heterogeneous system is characterized by comprising a table body (1), 3N quartz flexible accelerometers (2), an MEMS module (3), a host module (6), a power supply module (4) and a signal resolving module, wherein N is more than or equal to 1; the output ends of the 3N quartz flexible accelerometers (2) are connected with a signal resolving module and are divided into three groups for measuring visual acceleration information of an x axis, a y axis and a z axis respectively; the MEMS module (3) comprises an MEMS gyroscope and 3N MEMS accelerometers; The MEMS gyroscope is a triaxial gyroscope and is used for measuring angular motion information of a carrier relative to an inertial space, and the output end of the MEMS gyroscope is connected with the signal resolving module; The 3N MEMS accelerometers are divided into three groups and are respectively used for measuring visual acceleration information of an x axis, a y axis and a z axis, and the output ends of the three groups of MEMS accelerometers are respectively connected with the signal resolving module; the output end of the signal resolving module is connected with the host module (6) and is used for converting the angular motion information and the visual acceleration information into data formats matched with the host and transmitting the data formats to the host; The output end of the power supply module (4) is respectively connected with 3N quartz flexible accelerometers (2), 3N MEMS accelerometers, an MEMS gyroscope, a host module (6) and a signal resolving module; the host module (6) is used for being connected with external equipment to output the processed angular velocity and acceleration; the quartz flexible accelerometers (2) are arranged on the top surface of the table body (1), the MEMS accelerometers, the MEMS gyroscopes and the power supply modules (4) are arranged in the inner cavity of the table body (1) and are spaced, and the host computer modules (6) are arranged on the bottom surface of the table body (1).
2. A redundant inertial measurement unit based on a heterogeneous system according to claim 1, wherein: The MEMS accelerometer and the MEMS gyroscope are respectively connected with the output end of the power supply module (4) through the low-dropout linear voltage stabilizer.
3. A redundant inertial measurement unit based on a heterogeneous system according to claim 2, wherein: The power supply module (4) comprises a direct current power supply port and a power supply conversion module; the direct current power supply port is 25-31V, and the output end of the direct current power supply port is connected with the power supply conversion module; the output end of the power conversion module is respectively connected with the host module (6), the 3N quartz flexible accelerometers (2), the signal resolving module and the low-dropout linear voltage stabilizer for power supply.
4. A redundant inertial measurement unit based on a heterogeneous system according to claim 1, wherein: the vibration absorber also comprises a plurality of rubber vibration absorbers (5) which are respectively arranged at the joint of the table body (1) and other equipment and are used for absorbing and isolating external vibration.
5. A redundant inertial measurement unit based on a heterogeneous system according to any one of claims 1-4, characterized in that it comprises the following steps: 1) The MEMS gyroscope measures angular motion information of a carrier relative to an inertial space and is used as the finally output angular velocity, and the MEMS accelerometer and the quartz flexible accelerometer (2) on the x axis, the y axis and the z axis measure visual acceleration information of the carrier relative to the inertial space, wherein the sampling interval in the visual acceleration information is dt; The visual acceleration information comprises measurement output N a of 3N MEMS accelerometers or 3N quartz flexible accelerometers (2), equivalent K a , zero offset D a , measurement matrix H a and measurement noise V a ; 2) Constructing a weighting matrix W of the MEMS accelerometer and the quartz flexible accelerometer (2), wherein the calculation formula of the weighting matrix W is as follows: Wherein Ω n refers to the zero bias stability of the nth MEMS accelerometer or quartz flexible accelerometer (2), n=6n; 3) Estimating the real output value DeltaV of the MEMS accelerometer or the quartz flexible accelerometer (2) according to a least square method to obtain the suboptimal estimated value of the MEMS accelerometer or the quartz flexible accelerometer (2) The calculation formula of (2) is as follows: 4) Using a weighting matrix W for sub-optimal estimates Performing data fusion processing to obtain the optimal estimated value of the MEMS accelerometer or the quartz flexible accelerometer (2) The calculation formula is as follows: 5) Comparing performance parameters of MEMS accelerometer and quartz flexible accelerometer (2) on x axis, y axis and z axis during measuring apparent acceleration information, selecting optimal estimated value of accelerometer with smaller performance parameters As the acceleration of the final output, inertial measurement is completed.
6. The heterogeneous system-based redundant inertial measurement method of claim 5, wherein: in step 5, the performance parameters include mean, stability, scale factor stability.

Description

Redundant inertial measurement unit and method based on heterogeneous system Technical Field The invention relates to an inertial measurement unit and a measurement method, in particular to a redundant inertial measurement unit and a measurement method based on a heterogeneous system. Background An Inertial Measurement Unit (IMU) is a device for measuring the three-axis angular rate and acceleration of an object, and mainly comprises an accelerometer and a gyroscope. The accelerometer can measure acceleration of the object in three axial directions, and the gyroscope can measure angular velocity of the object in three-dimensional space. In the existing inertial measurement unit based on MEMS (micro electro mechanical system), a core component MEMS gyroscope and an MEMS accelerometer are concentrated on a host circuit board through glue, so that the MEMS device is not easy to maintain and assemble, signals are easy to cross talk with each other, and the reliability of the MEMS module is poor in a low-temperature environment. The existing inertial measurement unit can also use a single optical fiber gyroscope or a laser gyroscope and a quartz flexible accelerometer, compared with the inertial measurement unit based on MEMS, the structure, the volume and the weight of the scheme are greatly increased, the portability and the integration degree are poor, in addition, the gyroscope and the accelerometer are influenced by factors such as a manufacturing process and the like, measurement errors exist, and the measurement precision is easily limited by inertial device hardware. Disclosure of Invention The invention aims to solve the technical problems that the existing inertial measurement unit based on an MEMS gyroscope and an MEMS accelerometer is easy to cross talk and difficult to disassemble and assemble due to the fact that the existing inertial measurement unit based on an MEMS gyroscope and an MEMS accelerometer is poor in portability and integration degree due to the fact that the existing inertial measurement unit based on a single optical fiber gyroscope or a laser gyroscope and a quartz flexible accelerometer is poor in portability and integration degree, and provides a redundant inertial measurement unit based on a heterogeneous system and a measurement method. In order to solve the technical problems, the technical solution provided by the invention is as follows: the redundant inertial measurement unit based on the heterogeneous system is characterized by comprising a table body, 3N quartz flexible accelerometers, an MEMS module, a host computer module, a power supply module and a signal resolving module, wherein N is more than or equal to 1; The output ends of the 3N quartz flexible accelerometers are connected with the signal resolving module and are divided into three groups for measuring visual acceleration information of an x axis, a y axis and a z axis respectively; The MEMS module comprises an MEMS gyroscope and 3N MEMS accelerometers; The MEMS gyroscope is a triaxial gyroscope and is used for measuring angular motion information of a carrier relative to an inertial space, and the output end of the MEMS gyroscope is connected with the signal resolving module; The 3N MEMS accelerometers are divided into three groups and are respectively used for measuring visual acceleration information of an x axis, a y axis and a z axis, and the output ends of the three groups of MEMS accelerometers are respectively connected with the signal resolving module; The output end of the signal resolving module is connected with the host module and is used for converting the angular motion information and the visual acceleration information into data formats matched with the host and transmitting the data formats to the host; the output end of the power supply module is respectively connected with 3N quartz flexible accelerometers, 3N MEMS accelerometers, an MEMS gyroscope, a host module and a signal resolving module; The host module is used for being connected with external equipment to output the processed angular speed and acceleration; the 3N quartz flexible accelerometers are arranged on the top surface of the table body, the 3N MEMS accelerometers, the MEMS gyroscope and the power supply module are all arranged in the inner cavity of the table body and are spaced from each other, and the host module is arranged on the bottom surface of the table body. The MEMS accelerometer and the MEMS gyroscope are respectively connected with the power supply module through the low-dropout linear voltage stabilizer. Further, the power supply module comprises a direct current power supply port and a power supply conversion module; the direct current power supply port is 25-31V, and the output end of the direct current power supply port is connected with the power supply conversion module; the output end of the power conversion module is respectively connected with the host module, the 3N quartz flexible accelerometers, the si