Inertial measurement method for swing of large flexible mechanism
The MEMS inertial sensor and microcontroller software coordinated to measure the swing of a large flexible mechanism, which solves the problem of difficulty in measuring swing in outdoor environments, and realizes accurate monitoring and real-time feedback of the swing parameters of the flexible mechanism, ensuring the safe management and stable operation of the mechanism.
Patent Information
- Application Number
- CN202411876153.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2024-12-19
- Publication Date
- 2025-06-13
AI Technical Summary
In monitoring of large flexible mechanisms, it is difficult to accurately measure its swing, especially in outdoor environments, due to the difficulty in establishing zero references, the lack of direct measurement means and the difficulty in transmitting measurement data in a timely manner.
The MEMS inertial sensor is used to measure the angular rate and acceleration of the axial swing of the X, Y, and Z mechanisms, and the attitude navigation solution is performed through the microcontroller software, the pitch angle and roll angle are calculated, the angular rate channel data sequence is analyzed to judge the swing period, and the spatial swing value is obtained through vector calculations, and finally the data is output through the wireless communication module.
It realizes accurate measurement of the swing amplitude of large flexible mechanisms, can monitor the swing period and amplitude dynamic information in real time, reduces safety misjudgment and risk assessment deviation caused by measurement errors, and ensures the stable operation of the mechanism in harsh environments.
Smart Images
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Abstract
Description
Technical Field
[0001] The present invention belongs to the technical field of sensor measurement, and particularly relates to an inertial measurement method for the swing amplitude of a large flexible mechanism. Background Art
[0002] In the monitoring of large flexible mechanisms, accurately measuring their swing amplitude is crucial. Commonly used MEMS inertial sensors include gyroscopes (for angular rate measurement) and accelerometers (for linear acceleration measurement), which have the advantages of solid state, small size, low power consumption, and resistance to impact and vibration. Their output forms include voltage, current, SPI communication, etc. When analog output is used, analog-to-digital conversion is required. The measurement system usually reads the digital signal by a microcontroller and uploads it to the host computer.
[0003] Outdoor large facilities such as long-span suspension bridges, photovoltaic frames, and communication signal towers generate yaw (period 1 - 10 s) under the action of wind force during drastic climate changes. Due to the complex outdoor environment and long measurement distance, there are many difficulties in measuring their yaw amplitude: it is difficult to establish a zero reference, there is a lack of direct measurement means, and it is difficult to transmit measurement data to the network in a timely manner.
[0004] The Lora long-distance wireless transmission technology is based on spread-spectrum modulation, with a rate of several hundred bps to several tens of Kbps and a transmission distance of 100 m to 10 Km, which meets the communication requirements for small amounts of data outdoors. Summary of the Invention
[0005] The purpose of the present invention is to address the above problems and provide an inertial measurement method for the swing amplitude of a large flexible mechanism to meet the requirements of safety monitoring and protective control.
[0006] To achieve the above object, the present invention adopts the following technical solutions: An inertial measurement method for the swing amplitude of a large flexible mechanism, comprising the following steps: Step 1: Use a MEMS inertial sensor to measure the angular rate and acceleration of the mechanism's swing in the X, Y, and Z axes; Step 2: The microcontroller software of the measurement system reads the sensor data. The measurement system takes the microcontroller minimum system as the core and includes a power supply module, an inertial measurement module, a microcontroller system, and a wireless communication module; Step 3: The microcontroller software performs attitude navigation solution on the angular rate and acceleration values measured by the MEMS inertial sensor to obtain the pitch angle θ of the swing along the Y direction and the roll angle ; Step 4: The microcontroller software obtains the swing period of the mechanism through the analysis and comprehensive polarity judgment of the data sequence of the angular rate channel within a certain time interval; Step 5: The microcontroller software performs vector calculation based on the swing angle and swing period to obtain the spatial swing amplitude value; Step 6: The microcontroller software drives the wireless communication module through the UART serial port to output the measured data; Step 7: The user terminal far from the site can receive the measurement data through the wireless communication module (network) to obtain the swing parameters of the flexible mechanism.
[0007] In the above inertial measurement method for the swing amplitude of a large flexible mechanism, the MEMS inertial sensor includes 3 MEMS gyroscopes and 3 MEMS accelerometers. The data output of the MEMS inertial sensor is the SPI interface. These sensors are respectively installed on the X, Y, and Z axes of the mechanism carrier. Each direction includes 1 MEMS gyroscope and 1 MEMS accelerometer, jointly forming an inertial measurement unit in three spatial directions.
[0008] In the above inertial measurement method for the swing amplitude of a large flexible mechanism, the pitch angle θ and the roll angle of the swing along the Z direction are calculated respectively according to the following formulas .
[0009] In the above inertial measurement method for the swing amplitude of a large flexible mechanism, based on a certain time interval set according to the common mechanism swing period, the angular rate channel data sequence is collected. Within this time interval, at least data of no less than 3 swing periods should be collected. By double analyzing and judging the amplitude and polarity of the data of the 3 angular rate channels, the average swing period is obtained. If the swing angular rate amplitude of each channel is lower than the set value, it is determined that the mechanism has no swing, and no subsequent analysis, judgment, and period calculation are performed. The swing period T is calculated according to the following formula .
[0010] In the above inertial measurement method for the swing amplitude of a large flexible mechanism, based on the fact that the swing motion of the flexible mechanism conforms to the motion law of the standard simple pendulum model, first, according to the simple pendulum swing period calculation formula the equivalent swing radius of the flexible mechanism is obtained through conversion , and then according to the formulas , the swing amplitude P along the Y direction y and the swing amplitude P along the Z direction z are calculated respectively. Finally, the spatial swing amplitude value is obtained through the vector calculation formula .
[0011] In the above inertial measurement method for the swing amplitude of a large flexible mechanism, the UART serial port mentioned in Step 6 is a universal asynchronous communication transceiver integrated on the microcontroller, which can exchange data with terminal devices having RS232 or RS422 / 485 communication ports.
[0012] In the above-mentioned inertial measurement method for the swing amplitude of a large flexible mechanism, the user-side wireless communication module described in step seven is a same-specification Lora long-distance wireless communication module paired with the measurement output end. The paired user-side wireless communication module can receive measurement data at a distance greater than 100m in an environment with obstacles and greater than 1000m in an open environment.
[0013] In the above-mentioned inertial measurement method for the swing amplitude of a large flexible mechanism,
[0014] Compared with the existing technologies, the beneficial effects of the present invention are as follows: 1. In this inertial measurement method for the swing amplitude of a large flexible mechanism, through the cooperation of MEMS inertial sensors and advanced microcontroller software, the swing amplitude of the large flexible mechanism is accurately measured. With the multi-axis sensor layout and precise algorithm, the swing parameters of the mechanism in the X, Y, and Z axes are accurately captured. Even the minute swing of a suspension bridge can be accurately quantified, effectively avoiding safety misjudgments and risk assessment deviations caused by measurement errors, and laying a solid foundation for the safety management of large flexible mechanisms. With high-sensitivity sensors and a high-speed data processing mechanism, the swing amplitude changes of the mechanism are monitored in real time, data is collected and processed at short time intervals, and the dynamic information of the swing period and amplitude is quickly fed back. In complex working conditions such as sudden wind changes, it helps the operation and maintenance personnel to respond and adjust immediately, ensuring the stable operation of the mechanism in harsh environments.
[0015] 2. In this inertial measurement method for the swing amplitude of a large flexible mechanism, the entire measurement system has a rigorous architecture. With a high-performance microcontroller as the core, each module cooperates and complements each other. The power supply module provides stable power supply, the inertial measurement module accurately senses, the software performs intelligent calculation, and the wireless communication module transmits reliably, ensuring continuous and accurate data, and reducing maintenance costs and downtime risks. Specific embodiments
[0016] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments.
[0017] An inertial measurement method for the swing amplitude of a large flexible mechanism includes the following steps: Step 1: Use MEMS inertial sensors to measure the angular velocity and acceleration of the mechanism's swing in the X, Y, and Z axes; The MEMS inertial sensors include 3 MEMS gyroscopes and 3 MEMS accelerometers. It is required that the data output of the MEMS inertial sensors is in the SPI interface. These sensors are respectively installed on the X, Y, and Z axes of the mechanism carrier. Each direction includes 1 MEMS gyroscope and 1 MEMS accelerometer, jointly forming an inertial measurement unit in 3 spatial directions; The X, Y, and Z axes refer to the three rotational degree-of-freedom coordinate system axes of the mechanism in the outdoor space. Among them, the X axis is defined as azimuth, the Y axis is defined as roll, and the Z axis is defined as pitch. The three axes are pairwise orthogonal and conform to the right-hand rule.
[0018] Step 2: The measurement system microcontroller software reads the sensor data measurement data. The measurement system is designed with the microcontroller as the core. The measurement system is designed with the microcontroller minimum system as the core, mainly including a power supply module, an inertial measurement module, a microcontroller system, and a wireless communication module, etc. The microcontroller selects the STM32F103 of the ARM series or a microcontroller with the same performance. The controller has an SPI communication interface for data communication with the MEMS inertial sensor. The microcontroller software is the swing amplitude measurement and calculation software, developed using the common Keil uVision embedded system integrated development environment for ARM series microcontrollers, mainly including software modules such as data acquisition, measurement calculation, and communication output.
[0019] Step 3: The microcontroller software performs attitude navigation calculation on the angular rate and acceleration values measured by the MEMS inertial sensor to obtain the pitch angle θ of the swing along the Y direction and the roll angle ; The navigation calculation method is a general technical method in the inertial technology industry, which can perform projection and integral transformation on the angular rate and acceleration values output by the sensor to obtain the attitude angle of the navigation coordinate system and other navigation parameters.
[0020] The pitch angle θ of the swing along the Y direction is the angle formed by the Y axis and the horizontal plane after the carrier rotates around the Z axis. The pitch angle θ is simply calculated according to formula (1).
[0021] …………………(1) Where ax, zy, and az are the measured values of the accelerometers on the X, Y, and Z axes respectively; The roll angle of the swing along the Z direction is the angle formed by the Z axis and the horizontal plane after the carrier rotates around the Y axis. The roll angle is simply calculated according to formula (2).
[0022] …………………(2) Step 4: The microcontroller software obtains the swing period of the mechanism through the analysis and comprehensive polarity judgment of the data sequence in the angular rate channel within a certain time interval. A certain time interval (such as 10s) is the data sequence acquisition time proposed based on the swing period of common mechanisms. In principle, within one time interval, at least the data of no less than 3 swing periods should be collected. The analysis and comprehensive polarity judgment of the data sequence perform a dual analysis and judgment of the amplitude and polarity of the data of the three angular rate channels. The data sequence has a fixed sampling output time interval TS, for example, one data point every 2 ms. If the swing angular rate amplitudes of each channel are all lower than the set value (for example, 3° / s), it is considered that the mechanism does not swing, and no further analysis and judgment are carried out. Since the time difference of polarity change is related to the swing period, the period measurement is to determine the start point of the data point where the angular rate ω data sequence changes from monotonically increasing to monotonically decreasing, and the next data point where it changes from monotonically increasing to monotonically decreasing is the end point, and the swing period formula (3) is calculated; …………………(3) where TS is the data sampling output time interval, and N1 and N2 are the end point and start point timestamp serial numbers of the data changing from monotonically increasing to monotonically decreasing.
[0023] Step Five: The microcontroller software performs vector calculation based on the swing angle and swing period to obtain the spatial swing amplitude; The swing angle is the pitch angle θ swinging along the Y direction and the roll angle Φ swinging along the Z direction. For the swing motion of the flexible mechanism, it is consistent with the standard simple pendulum model. The subsequent calculation refers to the standard simple pendulum period calculation formula shown in formula (4). According to formula (4), the calculation formula (5) for the equivalent swing radius L can be obtained; …………………(4) …………………(5) where T is the simple pendulum swing period, L is the pendulum string length (equivalent swing radius), and g is the acceleration due to gravity (taking 9.8 m / s2); The swing amplitude Py along the Y direction and the swing amplitude Pz along the Z direction are calculated according to formula (6) and formula (7) respectively; …………………(6) …………………(7) where the pitch angle θ and the roll angle are in radian values.
[0024] The vector calculation is a method for synthesizing the actual spatial swing amplitude value P of the flexible mechanism through the swing amplitude Py along the Y direction and the swing amplitude Pz along the Z direction, as shown in formula (8).
[0025] …………………(8) Step Six: The microcontroller software drives the wireless communication module through the UART serial port to output the measured data; The UART serial port is a general asynchronous communication transceiver integrated on the microcontroller, which can exchange data with terminal devices having RS232 or RS422 / 485 communication ports; The wireless communication module is a Lora long-distance wireless communication module HC-14 or a module of the same type, and has an RS485 communication interface.
[0026] Step 7: The user terminal far from the site can receive the measurement data through the wireless communication module (network) to obtain the swing parameters of the flexible mechanism; The wireless communication module is a Lora long-distance wireless communication module HC-14 or a module of the same type paired with the measurement end, and has an RS485 communication interface. The obstacle reception distance of the Lora wireless communication module is more than 100m, and the reception distance in an open environment is more than 1000m.
[0027] The above are only the preferred embodiments of the present invention, and are not intended to limit the present invention. Any modifications, equivalent replacements, improvements, etc. made within the spirit and principle of the present invention shall be included in the protection scope of the present invention.
Claims
1. A method for measuring the inertia of a large flexible mechanism swing, characterized in that: The steps include: Step 1: Use MEMS inertial sensors to measure the angular velocity and acceleration of the X, Y, and Z axis swing of the mechanism; Step 2: The sensor data is read by the measurement system microcontroller software. The measurement system is based on the microcontroller minimum system, including power module, inertial measurement module, microcontroller system and wireless communication module; Step 3: The microcontroller software performs attitude navigation on the angular rate and acceleration values measured by the MEMS inertial sensor to obtain the pitch angle θ along the Y direction and the roll angle along the Z direction. ; Step 4: The microcontroller software obtains the swing period of the mechanism by analyzing the angular rate channel data sequence within a certain time interval and making a comprehensive polarity judgment; Step 5: The microcontroller software performs vector calculation based on the swing angle and the swing period to obtain the spatial swing amplitude value; Step 6: The microcontroller software drives the wireless communication module through the UART serial port to output the measured data; Step 7: The user end far away from the site can receive the measurement data through the wireless communication module (network) to obtain the swing parameters of the flexible mechanism.
2. The inertial measurement method of the swing amplitude of a large-scale flexible mechanism according to claim 1 is characterized in that: The MEMS inertial sensor includes three MEMS gyroscopes and three MEMS accelerometers. The data output of the MEMS inertial sensor is an SPI interface. These sensors are respectively installed in the X, Y, and Z axes of the mechanism carrier. Each direction includes one MEMS gyroscope and one MEMS accelerometer, which together constitute an inertial measurement unit in three directions of space.
3. The inertial measurement method of the swing amplitude of a large-scale flexible mechanism according to claim 1 is characterized in that: The pitch angle θ and the roll angle along the Z direction are Calculate according to the following formula 。 4. The inertial measurement method of the swing amplitude of a large-scale flexible mechanism according to claim 1 is characterized in that: The angular velocity channel data sequence is collected at a certain time interval set based on the common mechanism swing cycle. At least 3 swing cycle data should be collected within this time interval. The swing cycle average value is obtained by double analysis and judgment of the amplitude and polarity of the 3 angular velocity channel data. If the swing angular velocity amplitude of each channel is lower than the set value, it is determined that the mechanism has no swing, and no subsequent analysis and judgment and cycle calculation are performed. The swing cycle T is calculated according to the following formula 。 5. The inertial measurement method of the swing amplitude of a large-scale flexible mechanism according to claim 1 is characterized in that: Based on the fact that the swing motion of the flexible mechanism is consistent with the motion law of the standard simple pendulum model, the swing period of the single pendulum is calculated according to the formula Convert to get the equivalent flexible mechanism swing radius , and then according to the formula , Calculate the swing amplitude P along the Y direction respectively y and the swing amplitude P along the Z direction z , and finally through the vector calculation formula Obtain the value of the spatial swing amplitude.
6. The inertial measurement method of the swing amplitude of a large-scale flexible mechanism according to claim 1 is characterized in that: The UART serial port described in step six is a universal asynchronous communication transceiver integrated on the microcontroller, which can exchange data with a terminal device having an RS232 or RS422 / 485 communication port.
7. The inertial measurement method of the swing amplitude of a large-scale flexible mechanism according to claim 1 is characterized in that: The user-end wireless communication module described in step seven is a Lora long-distance wireless communication module of the same specification paired with the measurement output terminal. The paired user-end wireless communication module can receive measurement data at a receiving distance greater than 100m in an obstructed environment and a receiving distance greater than 1000m in an open environment.