A carrier motion measuring device based on MEMS inertial navigation

Abstract

The utility model relates to a kind of carrier motion measuring device based on MEMS inertial navigation, including bottom plate, outer cover, inner cover, temperature control module and six-axis MEMS inertial navigation module, information processing module, WIFI communication module, power supply module installed on bottom plate, inner cover is covered in inside with six-axis MEMS inertial navigation module, information processing module, WIFI communication module, power supply module, outer cover is set in the outside of inner cover, and gap is left between outer cover and inner cover;Temperature control module includes temperature sensor and heating sheet, temperature sensor and heating sheet are all installed on the outer surface of six-axis MEMS inertial navigation module, adsorption fixing mechanism is equipped on the bottom surface of bottom plate, temperature sensor is fed back to information processing module with acquisition temperature, information processing module is connected with six-axis MEMS inertial navigation module, and information processing module controls the heating power of heating sheet.The utility model can improve measurement accuracy.

Description

Technical Field

[0001] This utility model relates to the field of carrier motion measurement, specifically to a carrier motion measurement device based on MEMS inertial navigation. Background Technology

[0002] The measurement of velocity and angular velocity of moving objects often faces numerous challenges in complex applications, including external signal interference, insufficient environmental adaptability, and high cost. MEMS inertial navigation systems are inertial measurement devices based on microelectromechanical systems. This system, through highly integrated miniaturized gyroscopes, accelerometers, and other sensors using MEMS technology, exhibits several significant advantages in measuring the motion state of a vehicle: it achieves autonomous measurement through internal accelerometers and gyroscopes, eliminating reliance on external signals and making it suitable for signal-obstructed environments such as indoors and underwater; its miniaturized architecture, through highly integrated technology, significantly reduces size and weight, flexibly adapting to space- or load-sensitive applications; relying on semiconductor mass production processes, the system significantly reduces manufacturing costs while maintaining performance; and the absence of mechanical moving parts enhances the system's reliability and resistance to external environmental factors such as vibration and shock.

[0003] Given the aforementioned advantages, applying low-cost MEMS inertial navigation systems to motion measurement of vehicles is a promising technical approach for achieving real-time monitoring of the velocity and angular velocity of moving objects. However, MEMS inertial sensors are highly sensitive to changes in ambient temperature. Temperature variations can cause changes in sensor zero bias and scaling factor, thus affecting measurement accuracy. Especially in complex application environments, such as outdoors or with significant temperature variations, temperature drift becomes one of the main factors affecting the accuracy and stability of MEMS inertial navigation systems. Therefore, effectively suppressing the impact of temperature on the accuracy of MEMS sensors and improving the system's stability in variable temperature environments is a crucial technical problem that needs to be solved.

[0004] Therefore, this invention uses a MEMS inertial navigation system to achieve real-time monitoring of the speed and angular velocity of moving objects, and adopts heat insulation and active temperature control design in its structure to suppress the influence of complex environmental temperature on the sensor and ensure the application accuracy of the sensor in complex environments. Utility Model Content

[0005] This utility model discloses a carrier motion measurement device based on MEMS inertial navigation, which has the technical advantages of high measurement accuracy and low cost.

[0006] To achieve the above objectives, the technical solution adopted by this utility model is as follows: A carrier motion measurement device based on MEMS inertial navigation includes a base plate, an outer shell, an inner shell, a six-axis MEMS inertial navigation module, an information processing module, a WIFI communication module, a power supply module, and a temperature control module. The six-axis MEMS inertial navigation module, information processing module, WIFI communication module, and power supply module are all mounted on the base plate. The inner shell is mounted on the base plate and encloses the six-axis MEMS inertial navigation module, information processing module, WIFI communication module, and power supply module inside. The outer shell is fitted over the inner shell and is fixedly connected to the base plate, with a gap between the outer shell and the inner shell. The temperature control module includes a temperature sensor and a heating element, both mounted on the outer surface of the six-axis MEMS inertial navigation module. An adsorption and fixing mechanism is provided on the bottom surface of the base plate. The temperature sensor feeds back the collected temperature to the information processing module, which is connected to the six-axis MEMS inertial navigation module and controls the heating power of the heating element.

[0007] Furthermore, five temperature sensors are provided, which are respectively located on the top surface and four sides of the six-axis MEMS inertial navigation module.

[0008] Furthermore, two heating elements are provided, which are respectively located on two opposite sides of the six-axis MEMS inertial navigation module.

[0009] Furthermore, four adsorption and fixing mechanisms are provided, located at the four corners of the base plate, and each adsorption and fixing mechanism includes a magnet.

[0010] Furthermore, the carrier motion measuring device also includes a horizontal adjustment mechanism, which includes a level and adjusting bolts. The level is installed on the top of the outer casing, and the adjusting bolts are located at the four corners of the base plate. The adjusting bolts are used to adjust the distance between the base plate and the mounting surface.

[0011] Furthermore, the magnet is fixedly installed at the end of the adjusting bolt, and a protective shell is provided on the outer periphery of the magnet. The protective shell, the magnet, and the adjusting bolt are integrated into one unit.

[0012] Furthermore, the information processing module uses an STM32 series microprocessor.

[0013] Furthermore, the power supply module is powered by a lithium battery.

[0014] Furthermore, the temperature sensor is a DS18B20. Furthermore, the level is a bubble level.

[0015] The beneficial effects of this utility model are as follows: 1) The use of low-cost MEMS inertial sensors for measurement significantly reduces equipment costs; 2) The temperature control module maintains the MEMS inertial sensor at a constant temperature, effectively suppressing temperature drift and improving measurement accuracy and stability. The heat insulation cavity design effectively reduces the power consumption of temperature control, which is beneficial for constant temperature control. 3) The installation of the measuring device is simplified by using a horizontal adjustment mechanism and an adsorption fixing mechanism, which can improve the installation level and further improve the measurement accuracy; 4) Supports WIFI wireless communication, facilitating system integration and remote monitoring; 5) It has a compact structure and low power consumption, making it suitable for motion measurement applications on various mobile carriers. Attached Figure Description

[0016] Figure 1 This is a block diagram illustrating the structural principle of the carrier motion measurement device in the embodiment; Figure 2 This is a schematic diagram of the external structure of the carrier motion measuring device in the embodiment; Figure 3 for Figure 2 Structural diagram from an upward angle; Figure 4 for Figure 2 Exploded view; Figure 5 This is a schematic diagram of the structure of the six-axis MEMS inertial navigation module in the embodiment; Figure 6 for Figure 5 Side view; Figure 7 This is a schematic diagram of the adsorption and fixation mechanism in the embodiment; Figure 8 A schematic diagram showing the state of the carrier motion measuring device adsorbed onto the object being lifted by the crane. Figure 9 This is a schematic diagram showing the state of the carrier motion measuring device adsorbed on the cantilever of a tower crane.

[0017] Figure label: 1. Six-axis MEMS inertial navigation module; 2. Information processing module; 3. WIFI communication module; 4. Power supply module; 5. Temperature control module; 6. Horizontal adjustment mechanism; 7. Adsorption and fixing mechanism; 8. Outer shell; 9. Inner shell; 10. Base plate; 11. Heating element; 12. Temperature sensor; 13. Adjusting bolt; 14. Magnet; 15. Protective shell; 16. Carrier motion measurement device. Detailed Implementation

[0018] The technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments of the present invention.

[0019] This embodiment discloses a carrier motion measurement device based on MEMS inertial navigation. Its core component is a six-axis MEMS inertial navigation module 1, a commercially available product. This module is a navigation parameter calculation system using gyroscopes and accelerometers as sensing devices. It is a miniature device or system integrating microsensors, microactuators, micromechanical structures, micropower supplies, signal processing and control circuits, high-performance electronic integrated devices, interfaces, and communication. This embodiment utilizes the six-axis MEMS inertial navigation module 1 to measure the angular velocity and acceleration of a moving carrier. To facilitate installation and simplify the overall structure of the measurement device, the six-axis MEMS inertial navigation module 1 is housed inside a casing, which forms a heat-insulating cavity to reduce heat exchange with the external environment, creating a favorable working environment for the module to operate at a constant temperature.

[0020] like Figure 1 As shown, the entire measurement device comprises a six-axis MEMS inertial navigation module 1, an information processing module 2, a WIFI communication module 3, a power supply module 4, and a temperature control module 5. The six-axis MEMS inertial navigation module 1 is used to acquire real-time triaxial acceleration and triaxial attitude angle information (including pitch, roll, and yaw angles) of the moving vehicle. Its data transmission frequency is 100Hz, and it maintains the same coordinate system as the moving vehicle. The information processing module 2 is connected to the six-axis MEMS inertial navigation module 1 via UART communication. It processes and calculates the acquired data and simultaneously acquires temperature sensor data from the temperature control module 5. Based on the acquired temperature data, it compares it with the set temperature to generate corresponding heating power and control the temperature stability of the six-axis MEMS inertial navigation module 1. In this embodiment, the information processing module 2 uses an STM32 series microprocessor. The WIFI communication module 3 is configured as a TCP server, listening on a specific port to receive commands from the upper-level system and send measurement data. The power supply module 4 provides working power to each functional module and provides the required heating power to the temperature control module 5. In this embodiment, the power supply module 4 is powered by a lithium battery and provides a suitable working voltage to each module through a voltage regulator circuit, especially providing sufficient power support for the heating element 11 of the temperature control module 5.

[0021] like Figures 2 to 4As shown, the entire motion measurement device housing includes a base plate 10, an outer shell 8, and an inner shell 9. Functional modules such as the six-axis MEMS inertial navigation module 1, information processing module 2, WIFI communication module 3, and power supply module 4 are mounted on the base plate 10 and covered and fixed to the base plate 10 by the inner shell 9, which has an open bottom. The outer shell 8 is fitted over the inner shell 9, with an open bottom. A gap is left between the outer shell 8 and the inner shell 9 to form a vacuum insulation cavity. The bottom of the outer shell 8 is fixed to the base plate 10. The insulation cavity design maintains the thermal stability inside the inner shell 9 while significantly reducing heating power. The temperature control module 5 includes a temperature sensor 12 and a heating element 11. To ensure good temperature uniformity within the inner shell 9, such as… Figure 5 and Figure 6 As shown, in this embodiment, a total of five temperature sensors 12 and two heating elements 11 are provided. The five temperature sensors 12 are respectively located on the top surface and four sides of the six-axis MEMS inertial navigation module 1 (i.e., Figure 5 The top, front, back, left, and right surfaces of the structure are shown, while the heating elements 11 are respectively located on... Figure 5 The front and rear of the six-axis MEMS inertial navigation module 1 shown are heated as uniformly as possible. In this embodiment, the temperature sensor 12 is a high-precision digital temperature sensor, such as DS18B20. The temperature sensor 12 monitors the temperature of the six-axis MEMS inertial navigation module 1 in real time. The information processing module 2 uses a PID control algorithm to control the power of the heating element 11 based on the received temperature data, thereby controlling the operating temperature of the six-axis MEMS inertial navigation module 1 near the set temperature point (e.g., 40℃±2℃), effectively suppressing the impact of temperature changes on measurement accuracy.

[0022] To further simplify the installation and fixation of the entire measuring device, a horizontal adjustment mechanism 6 and an adsorption fixing mechanism 7 are respectively provided at the four corners of the bottom of the base plate 10 in this embodiment. The horizontal adjustment mechanism 6 includes a level (not shown in the figure) and adjusting bolts 13. In this embodiment, a bubble level is used. The bubble level is installed on the top of the outer casing 8, and the position of the bubble in the level is observed to ensure that it is centered. By adjusting the height of the four adjusting bolts 13, the testing device is placed horizontally on the carrier surface, further improving the accuracy of the test results of the six-axis MEMS inertial navigation module 1. The adsorption fixing mechanism 7 in this embodiment uses a strong magnet to achieve rapid installation and fixation on the ferromagnetic carrier surface. Together with the horizontal adjustment mechanism 6, it ensures that the measuring device remains parallel to the carrier reference plane, improving measurement accuracy. Figure 3 and Figure 7As shown, in this embodiment, the adjusting bolt in the horizontal adjustment mechanism 6 and the adsorption fixing mechanism 7 are integrated. Specifically, a magnet 14 is placed on the outer periphery of the non-screw end of the adjusting bolt 13, fixing the magnet 14 to the adjusting bolt 13. A protective shell 15 is placed on the outer periphery of the magnet 14, making the protective shell 15, magnet 14, and adjusting bolt 13 a single unit. The carrier motion measuring device 16 in this embodiment can be installed as follows: Figure 8 The overhead crane can be used to lift items from the top, or it can be mounted on top of items such as... Figure 9 The top of the tower crane's cantilever can be fixed according to the location of the carrier to be measured. During installation, the carrier motion measuring device 16 is placed on the top surface of the moving carrier. The strong magnetic force of the four magnets 14 is used to attract it to the carrier surface. The bubble level is observed. According to the position of the bubble, the height is finely adjusted by rotating the adjusting bolts 13 at the corresponding corners until the bubble position is centered. At this time, it is indicated that the carrier motion measuring device 16 is parallel to the carrier surface.

[0023] The working principle of the carrier motion measuring device designed in this utility model is explained as follows: (1) The installation state of the carrier motion measuring device 16 is adjusted by the adsorption fixing mechanism 7 and the horizontal adjustment mechanism 6 to keep it as horizontal as possible, so as to facilitate rapid calibration and high-precision measurement.

[0024] (2) Temperature sensor 12 collects the temperature of the surface of the six-axis MEMS inertial navigation module 1 and feeds it back to information processing module 2. Information processing module 2 compares the received temperature data with the set temperature and generates the corresponding heating power. When the temperature is controlled to the set temperature range and stabilized, it enters the next step. At the same time, temperature control module 5 works at a certain frequency to ensure that the temperature remains stable in the set temperature range.

[0025] (3) Automatic gravity calibration: When the carrier motion measuring device 16 is stationary or slightly shaking, the local gravity acceleration value is accurately measured as a reference through the anti-shaking algorithm.

[0026] (4) Perform data preprocessing, use median filtering to eliminate sudden noise, and use a thresholding method based on the 3σ criterion. When the measured value is less than the noise threshold, it is considered to be in a stationary state, and the acceleration data is set to zero.

[0027] (5) Perform information calculation. Using the calibrated gravitational acceleration and attitude angle information, the measured values ​​are transformed to the carrier coordinate system through coordinate transformation. The velocity information is obtained through integration calculation, and the angular velocity information is obtained by subtracting the Earth's rotation component.

[0028] (6) The results are transmitted to the upper-level monitoring system via the WIFI communication module 3. The WIFI communication module 3 is configured in TCP server mode, supporting remote command reception and data transmission.

[0029] This utility model does not involve technical improvements to specific data processing methods and algorithms. The working principle given above is intended to introduce the working process of the carrier motion measuring device 16 when used for measuring moving carriers.

[0030] Although embodiments of the present invention 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 to these embodiments without departing from the principles and spirit of the present invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A carrier motion measurement device based on MEMS inertial navigation, characterized in that: The system includes a base plate, an outer shell, an inner shell, a six-axis MEMS inertial navigation module, an information processing module, a WIFI communication module, a power supply module, and a temperature control module. The six-axis MEMS inertial navigation module, information processing module, WIFI communication module, and power supply module are all mounted on the base plate. The inner shell is mounted on the base plate and encloses the six-axis MEMS inertial navigation module, information processing module, WIFI communication module, and power supply module inside. The outer shell is fitted over the inner shell and is fixedly connected to the base plate, with a gap between the outer shell and the inner shell. The temperature control module includes a temperature sensor and a heating element, both mounted on the outer surface of the six-axis MEMS inertial navigation module. An adsorption and fixing mechanism is provided on the bottom surface of the base plate. The temperature sensor collects the temperature data and feeds it back to the information processing module, which is connected to the six-axis MEMS inertial navigation module and controls the heating power of the heating element.

2. The carrier motion measurement device based on MEMS inertial navigation according to claim 1, characterized in that: Five temperature sensors are provided, which are respectively located on the top surface and four sides of the six-axis MEMS inertial navigation module.

3. The carrier motion measurement device based on MEMS inertial navigation according to claim 1, characterized in that: Two heating elements are provided, and the two heating elements are respectively located on two opposite sides of the six-axis MEMS inertial navigation module.

4. The carrier motion measurement device based on MEMS inertial navigation according to claim 1, characterized in that: The adsorption and fixing mechanism is provided in four parts, located at the four corners of the base plate, and the adsorption and fixing mechanism includes a magnet.

5. A carrier motion measurement device based on MEMS inertial navigation according to claim 4, characterized in that: The carrier motion measuring device also includes a horizontal adjustment mechanism, which includes a level and adjusting bolts. The level is installed on the top of the outer casing, and the adjusting bolts are located at the four corners of the base plate. The adjusting bolts are used to adjust the distance between the base plate and the mounting surface.

6. The carrier motion measurement device based on MEMS inertial navigation according to claim 5, characterized in that: The magnet is fixedly installed at the end of the adjusting bolt, and a protective shell is provided on the outer periphery of the magnet. The protective shell, the magnet, and the adjusting bolt are connected as one unit.

7. The carrier motion measurement device based on MEMS inertial navigation according to claim 1, characterized in that: The information processing module uses an STM32 series microprocessor.

8. The carrier motion measurement device based on MEMS inertial navigation according to claim 1, characterized in that: The power supply module is powered by a lithium battery.

9. A carrier motion measurement device based on MEMS inertial navigation according to claim 1, characterized in that: The temperature sensor used is a DS18B20.

10. A carrier motion measurement device based on MEMS inertial navigation according to claim 5, characterized in that: The level used is a bubble level.

Images