CN215524640U

CN215524640U - Accurate positioning and attitude tracking assembly based on semiconductor MEMS sensor

Info

Publication number: CN215524640U
Application number: CN202021691536.XU
Authority: CN
Inventors: 陈可; 李绍荣; 廖原; 杨秀洪
Original assignee: Anhui Lichuang Cloud Technology Co ltd
Current assignee: Anhui Lichuang Cloud Technology Co ltd
Priority date: 2020-08-14
Filing date: 2020-08-14
Publication date: 2022-01-14
Anticipated expiration: 2030-08-14

Abstract

The utility model discloses an accurate positioning and attitude tracking component based on a semiconductor MEMS sensor, which comprises: the MEMS device is integrated with a three-axis accelerometer, a three-axis gyroscope, a temperature sensor and a three-axis magnetometer; the MEMS device comprises an STM32F769 processor, a three-axis accelerometer, a three-axis gyroscope and a three-axis magnetometer of the MEMS device are connected with a data acquisition interface of the STM32F769 processor in an IIC or SPI mode; the MEMS device has small volume, low price and low power consumption. With the rapid development of the MEMS technology and the penetration into various discipline fields, various performances such as precision, robustness, dynamic response, etc. are greatly improved. The long-time accumulated error of the MEMS sensor is solved by using Kalman filtering, and long-time stable and reliable positioning and attitude measurement are realized. And modeling compensation is respectively carried out on errors of components of the system, so that the accuracy of attitude measurement is further improved.

Description

Accurate positioning and attitude tracking assembly based on semiconductor MEMS sensor

Technical Field

The utility model relates to the technical field of sensing measurement equipment, in particular to an accurate positioning and attitude tracking assembly based on a semiconductor MEMS sensor.

Background

With the development of small wearable personal navigation systems, personal navigation systems are used in more and more occasions, such as hospitals, museums, superstores and other indoor occasions. Among them, personal navigation systems based on the inertial technology have been widely studied because of their high accuracy in short-term positioning. In military and defense fields, such as rocket, ship and other fields, the inertial navigation technology is widely applied. Therefore, the research on inertial navigation technology meets the needs of business needs and national development. The traditional mechanical rotor gyro is based on Newton mechanics, and the basic equation is the theorem of moment of momentum. The mechanical rotation generates angular momentum, but the mechanical rotation must rely on support, so the support technology is the core technology of the mechanical rotor top. The limitation of the mechanical rotor gyroscope is the supporting technology, the better the gyroscope performance is, the more complex the required supporting technology is, the higher the corresponding cost is, and the popularization is limited. The inertial sensing system is a newly developed attitude tracking system, and an inertial measurement unit mainly comprises an accelerometer, a gyroscope and a magnetometer, but the current inertial navigation technology also has some problems. The current carrier attitude can be calculated by integrating the angular velocity values output by the gyroscope and then by knowing the initial attitude angle, however, since the gyroscope error is accumulated with time, it is not feasible to obtain the carrier attitude by the gyroscope only for a long time. The accelerometer measures unbiased gravity acceleration, and the attitude of the carrier can be calculated by matching with a three-axis magnetometer to measure local magnetic field components, but the gyroscopic-free attitude measurement unit receives a plurality of limitations: when the carrier is in a motion state, the output value of the accelerometer is the vector sum of the gravity acceleration and the motion acceleration, and the actual significance of attitude measurement is lost; magnetometers are greatly interfered by surrounding magnetic materials, and magnetometer measurement is accurate only in a closed environment.

Aiming at the technical problems, the utility model mainly provides an accurate positioning and attitude tracking component based on a semiconductor MEMS sensor, and solves the problems that an MEMS inertial device in the prior art is low in measurement accuracy and difficult to work continuously for a long time. The influence caused by a low-precision MEMS device can be compensated by using a high-precision navigation data fusion algorithm, and long-term stable and reliable positioning is realized. Meanwhile, the MEMS inertial sensor is very suitable for being applied to the wearable field due to the advantages of small volume and light weight.

Disclosure of Invention

The utility model aims to design a semiconductor MEMS sensor-based accurate positioning and attitude tracking component with low cost and simple structure, and provides a scheme which can solve the problem of high transient accuracy of an MEMS sensor, so that the MEMS sensor is in a high-accuracy state for a long time and can normally operate for a long time.

In order to achieve the purpose, the utility model provides the following technical scheme:

accurate positioning and attitude tracking assembly based on semiconductor MEMS sensor: the MEMS device is integrated with a three-axis accelerometer, a three-axis gyroscope, a temperature sensor and a three-axis magnetometer; the system also comprises an STM32F769 processor, wherein a three-axis accelerometer, a three-axis gyroscope and a three-axis magnetometer of the MEMS device are connected with a data acquisition interface of the STM32F769 processor in an IIC or SPI mode, a Flash memory is arranged in the STM32F769 processor, and an upper computer communication module of the STM32F769 processor is connected with external equipment through a crystal oscillator; and the power supply is respectively connected with the MEMS sensor and the STM32F769 processor.

The three-axis gyroscope is a FXAS21002C three-axis digital gyroscope, and is communicated with a host machine in an IIC or SPI mode.

The STM32F769 processor may communicate with an ethernet of an external device via an external port physical layer (PHY) chip, preferably a LAN8742 model.

The STM32F769 processor performs filtering processing on acquired data by using Kalman filtering to reduce the offset and measurement noise of the sensor in the whole data acquisition process, so that accurate motion information is obtained.

And the STM32F769 processor respectively performs filtering processing on the acquired real-time measurement data to reduce noise, then respectively establishes error models for the MEMS accelerometer, the gyroscope and the magnetometer, performs calibration technical analysis, and calibrates the real-time signal data.

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

the MEMS product is called a great reform of the traditional inertia measurement combination because of small volume, low price and low power consumption, and is increasingly applied to attitude measurement application. Moreover, with the rapid development of the MEMS technology and the penetration into various subject areas, various performances such as precision, robustness, dynamic response, etc. are greatly improved. The utility model solves the long-time accumulated error of the MEMS sensor by using Kalman filtering, and realizes long-term stable and reliable positioning and attitude measurement. The three-axis gyroscope selected by the utility model is provided with the temperature sensor, so that the generated temperature drift can be compensated better. The utility model respectively carries out modeling compensation on the errors of the components of the system, thereby further improving the accuracy of attitude measurement.

Drawings

FIG. 1 is a schematic structural view of the present invention;

FIG. 2 is a schematic diagram of a Kalman filter structure of the present invention;

in the figure: 1. a MEMS device; 2. an STM32F769 processor; 3. a power source.

Detailed Description

The technical solutions in the embodiments of the present invention will be clearly and completely described below with reference to the drawings in the embodiments of the present invention, and it is obvious that the described embodiments are only a part of the embodiments of the present invention, and not all of the embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present invention.

In the description of the present invention, it should be noted that the terms "vertical", "upper", "lower", "horizontal", and the like indicate orientations or positional relationships based on those shown in the drawings, and are only for convenience of describing the present invention and simplifying the description, but do not indicate or imply that the referred device or element must have a specific orientation, be constructed in a specific orientation, and be operated, and thus, should not be construed as limiting the present invention.

In the description of the present invention, it should also be noted that, unless otherwise explicitly specified or limited, the terms "disposed," "mounted," "connected," and "connected" are to be construed broadly and may, for example, be fixedly connected, detachably connected, or integrally connected; can be mechanically or electrically connected; they may be connected directly or indirectly through intervening media, or they may be interconnected between two elements. The specific meanings of the above terms in the present invention can be understood by those skilled in the art according to specific situations.

Referring to fig. 1-2, the present invention provides a technical solution:

Furthermore, the three-axis gyroscope selects an FXAS21002C three-axis digital gyroscope, communicates with the host computer in an IIC or SPI mode, has high sensitivity and low price in the similar system, is provided with a temperature sensor, can measure the working temperature of the gyroscope and is convenient for compensating the temperature drift of the sensor.

The working principle is as follows:

(1) referring to fig. 1, a structure diagram of an attitude measurement system is shown, the MEMS device integrates a three-axis accelerometer, a three-axis gyroscope and a three-axis magnetometer, selects a 9-axis MEMS device with low cost and low precision, and simultaneously measures sensor data in real time by using an STM32F769 processor to acquire attitude and positioning information.

(2) The adopted processor STM32F769 chip integrates a MAC802.3, can complete data handover with a physical layer, and only needs to be externally connected with a port physical layer (PHY) chip if Ethernet communication between the STM32F769 processor and external equipment is to be realized. The communication data line of PHY chip LAN8742 needs a transformer to connect with the RJ-45 hardware jack, and optionally, the RJ-45 interface with the transformer may be selected, or the transformer and the RJ-45 may be selected separately, and attention should be paid to the matching of the internal structure. The domestic H2019 transformer is selected to be matched with the RJ-45 hardware socket, noise between a network and equipment can be filtered through connection of the Ethernet transformer, mutual isolation and interference resistance can be achieved, and a chip is protected.

A. The micro inertial device data measurement module: and the microprocessor reads the data output by the inertia measurement unit through a corresponding SPI communication interface.

B. The attitude information processing module: the module needs to process the output data of the sensor, solve the attitude information and store the important data information in Flash.

C. The attitude information display module: the system is communicated with an upper computer in a serial port or Ethernet mode, and the attitude information is displayed in the upper computer.

(3) Wherein three-axis gyroscope selects FXAS21002C three-axis digital gyroscope, communicates with host computer through IIC or SPI mode, in the system of the same kind, sensitivity is higher, and low price to take temperature sensor certainly, can measure gyroscope operating temperature, be convenient for compensate sensor temperature drift.

(4) And filtering the acquired data by using Kalman filtering to reduce the offset and measurement noise of the sensor in the whole data acquisition process so as to obtain accurate motion information. The random linear discrete system kalman filter structure is shown in fig. 2. X_kIs an n-dimensional state vector, Z, of the system_kIs a systematic m-dimensional observation sequence, phi_k,k-1Is a systematic n x n dimensional state transition matrix, H_kIs an m x n dimensional observation matrix, K_kRepresenting the kalman gain.

(5) And respectively filtering the acquired real-time measurement data to reduce noise, then respectively establishing error models for the MEMS accelerometer, the gyroscope and the magnetometer, carrying out calibration technical analysis, and calibrating the real-time signal data.

Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes, modifications, substitutions and alterations can be made in these embodiments 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

1. An accurate positioning and attitude tracking component based on a semiconductor MEMS sensor is characterized in that: the MEMS device is integrated with a three-axis accelerometer, a three-axis gyroscope, a temperature sensor and a three-axis magnetometer; the system also comprises an STM32F769 processor, wherein a three-axis accelerometer, a three-axis gyroscope and a three-axis magnetometer of the MEMS device are connected with a data acquisition interface of the STM32F769 processor in an IIC or SPI mode, a Flash memory is arranged in the STM32F769 processor, and an upper computer communication module of the STM32F769 processor is connected with external equipment through a crystal oscillator; and the power supply is respectively connected with the MEMS sensor and the STM32F769 processor.

2. The semiconductor MEMS sensor-based fine positioning and attitude tracking assembly of claim 1 wherein: the three-axis gyroscope selects an FXAS21002C three-axis digital gyroscope and communicates with the host machine in an IIC or SPI mode.

3. The semiconductor MEMS sensor-based fine positioning and attitude tracking assembly of claim 1 wherein: the STM32F769 processor may communicate with an ethernet of an external device through an external port physical layer (PHY) chip, which is a LAN8742 type.