Measurement method capable of tracking and recording motion trail information of vibrating rod

Abstract

The invention relates to the technical field of radio orientation, in particular to a measuring method capable of tracking and recording motion trail information of a vibrating rod, which comprises the following steps: arranging at least four UWB (Ultra Wideband) base stations, fixing UWB transmitters at the joint of the vibrating end of the vibrating rod and a rubber tube, and fixing IMU (Inertial Measurement Unit) sensors at the vibrating end of the vibrating rod; according to the data output by the UWB transmitter and the IMU sensor, the position and posture of the vibrating rod in the detected target mold are calculated through a positioning algorithm, and the motion trail of the vibrating rod is further calculated; and according to the vibrating time, the vibrating area and the vibrating area overlapping degree of the vibrating rod, the vibrating state of the concrete is analyzed. The UWB technology and the IMU technology are fused, so that high-precision positioning of the vibrating rod can still be kept under the ground where wireless signals such as GPS signals cannot be transmitted, and the vibrating quality can be conveniently detected and evaluated.

Description

Technical Field

[0001] The invention relates to the technical field of radio orientation, in particular to a measuring method capable of tracking and recording movement trajectory information of a vibrating rod. Background Art

[0002] The compactness of concrete is one of the key factors to measure its overall quality. Good compactness helps ensure that concrete has ideal mechanical properties after solidification, such as high strength, high impermeability and excellent durability. During the construction stage, effective vibration can cause the concrete paste to flow and fill all pores, while expelling bubbles inside the concrete, so that the aggregate particles form close contact, thereby improving the microstructural integrity and overall performance of the concrete at a macro level.

[0003] During the construction process, if the vibration process does not meet the standards, it may lead to quality defects such as insufficient density and cold joints inside the concrete, which cannot be discovered and handled in time. Although the importance of vibration is widely recognized, as mentioned above, there are still great challenges in the quantitative control and theoretical research of the concrete vibration process. In the existing construction process, it is often more dependent on the experience of construction workers to judge whether the concrete is sufficiently vibrated. This method is highly subjective and variable, and is easily affected by various factors such as differences in operator skills and environmental changes, making it difficult to maintain consistent and stable vibration effects.

[0004] At present, some intelligent monitoring and automatic control systems have also appeared. Such systems can monitor the vibration trajectory, vibration time and related parameters in real time, realize scientific quantitative evaluation, thereby reducing human errors, and effectively preventing the occurrence of quality problems such as internal looseness of concrete, honeycombed surface, cold joints, etc. caused by improper vibration. Corrective measures can be taken at the first time, greatly improving the controllability and reliability of concrete engineering quality.

[0005] However, when faced with complex working conditions such as the casting of high-speed railway box girders, the harsh construction environment will shield wireless signals, causing conventional positioning sensors to fail, and the vibration time and vibration trajectory of the vibrating rod are difficult to measure, making real-time detection and quality assessment extremely difficult. Summary of the invention

[0006] In order to solve the problem that it is difficult to measure the vibration trajectory and vibration time of the vibrating rod and to accurately evaluate the concrete vibration quality in a harsh construction environment, the present invention provides a measurement method that can track and record the motion trajectory information of the vibrating rod.

[0007] The present invention provides a measurement method capable of tracking and recording the motion trajectory information of a vibrating rod, which adopts the following technical solution: A measurement method capable of tracking and recording the motion trajectory information of a vibrating rod comprises the following steps: At least four UWB base stations are deployed, with the UWB transmitter fixed at the connection between the vibrating end of the vibrating rod and the hose, and the IMU sensor fixed at the vibrating end of the vibrating rod; According to the data output by the UWB transmitter and the IMU sensor, the position and posture of the vibrator in the measured target are calculated through the positioning algorithm, and the motion trajectory of the vibrator is further calculated; The vibration state of concrete is analyzed based on the vibration time, vibration area, and degree of overlap of the vibration area of ​​the vibrating rod.

[0008] In a specific possible implementation scheme, after the analysis of the concrete vibration state is completed, different vibration states are marked with different colors on the model of the measured object.

[0009] In a specific possible implementation scheme, the UWB base station is 0.5m-2.5m higher than the target to be measured.

[0010] In a specific implementation scheme, the positioning algorithm includes a trilateration positioning algorithm and a multilateration positioning algorithm.

[0011] In a specific embodiment, the method for calculating the position of the vibrator in the measured object includes the following steps: Measure the signal transmission time between the vibrator and any three UWB base stations, and further calculate the distance between the vibrator and the UWB base station; Construct a three-dimensional space coordinate system, and transform the distance between the vibrator and the three UWB base stations into a nonlinear equation system in the three-dimensional space coordinate system; By solving the nonlinear equations, the estimated values ​​of the precise coordinates of the vibrating rod in the three-dimensional space coordinate system are obtained.

[0012] In a specific possible implementation scheme, when the signal strength of the UWB transmitter is less than or equal to a preset value, a state space model including state variables of position, velocity and attitude is established by a lossless Kalman filter algorithm; The distance obtained by the UWB base station is used to update the state variables in real time to obtain the measurement value; The state of the vibrator is predicted based on the acceleration and angular velocity measured by the IMU sensor; Calculate the lossless Kalman gain and correct the measured value; The measured values ​​and estimated values ​​are non-destructively fused to obtain the precise coordinate positioning of the vibrating rod in the three-dimensional space coordinate system.

[0013] In a specific possible implementation scheme, the motion trajectory of the vibrator is calculated by continuously acquiring data output by the UWB transmitter and the IMU sensor; Set the sliding window N, and perform weighted average calculation on the data at the current moment and the previous N-1 moments. The result after weighted average is the optimal output value at the current moment, and the positioning is denoised; The weights are in the form of a Gaussian kernel function that increases and decays over time.

[0014] In a specific possible implementation scheme, before analyzing the vibration state of concrete, the data output by the historical IMU sensor is divided into empty vibration state data and actual vibration state data; The empty vibration state data and the actual vibration state data are used as the input of the bidirectional LSTM neural network model, and the vibration state of the concrete is used as the output for model training. The bidirectional LSTM neural network model that has completed model training is used to judge the current vibration state of concrete.

[0015] In a specific possible implementation manner, the vibration time of the vibrating rod includes the vibration time of the vibrating rod at each position and the cumulative vibration time of the entire vibration process of the vibrating rod.

[0016] In a specific possible implementation scheme, when analyzing the vibration state of concrete, the vibration time of the vibrating rod at different times and positions, as well as the total vibration time of the overlapping part of the vibration range are displayed on the model of the measured object.

[0017] In summary, the present invention has the following beneficial effects: 1. By integrating UWB technology and IMU technology, it is possible to maintain high-precision positioning of the vibrator in underground areas where wireless signals such as GPS signals cannot be transmitted, making it easier to detect and evaluate the quality of the vibration.

[0018] 2. The weighted moving average algorithm further reduces the noise interference in the data, improves the positioning accuracy of the vibrator, and makes the obtained vibrator motion trajectory smoother.

[0019] 3. Through real-time monitoring of the vibrating rod, once problems such as insufficient vibration, normal vibration and excessive vibration are found, it is convenient for construction personnel to correct and adjust the construction plan in time.

[0020] 4. By visually outputting the motion path of the vibrating rod and the vibration status of the concrete, it is convenient to adjust the motion path of the vibrating rod in real time and improve the concrete vibration effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a flow chart of a measuring method capable of tracking and recording the movement trajectory information of a vibrating rod.

[0022] Figure 2 It is a schematic diagram of the UWB base station layout.

[0023] Figure 3 It is a flowchart of the positioning algorithm. DETAILED DESCRIPTION

[0024] The following combination Figure 1-Figure 3 The present invention is described in further detail.

[0025] To facilitate understanding, some technical terms are explained first.

[0026] UWB technology: Ultra-wideband technology is a positioning technology with high bandwidth, low power consumption, and strong anti-multipath interference capabilities. Its working principle is to send short pulse signals and calculate the distance at the receiving end based on the arrival time difference of the signal, thereby locating the target position. UWB technology can achieve a positioning range of tens of meters or even hundreds of meters, which is suitable for positioning needs in large construction sites. UWB signals have strong penetration capabilities and can penetrate obstacles such as walls and building structures. They are not affected by the environment, ensuring the stability and reliability of positioning. UWB technology has high-precision positioning. Although UWB technology has certain positioning errors, high-precision positioning results can be achieved through reasonable data processing and algorithm optimization.

[0027] IMU: Inertial Measurement Unit, is a device that uses sensors such as accelerometers and gyroscopes to measure the acceleration and angular velocity of an object in real time. IMU sensors can collect motion data of the object being measured in real time at a very high frequency, providing more detailed motion trajectory information. IMU technology has the characteristics of strong real-time performance, which can timely reflect the motion state of the object being measured and realize real-time monitoring and control of the motion process. IMU technology does not rely on external reference objects and can operate independently in various complex environments. It is suitable for special scenarios such as construction sites.

[0028] DTU: Data Transmission Unit, is a wireless terminal device dedicated to remote data transmission. It is widely used in the fields of Internet of Things (IoT), industrial automation, smart city construction, etc. The main function of DTU is to convert the data of serial port or other types of interfaces into a data format suitable for wireless network transmission, and send the data to the remote server through the mobile communication network. It can also receive the instructions issued by the server and convert them into corresponding control signals.

[0029] Reference Figure 1 The measurement method for tracking and recording the motion trajectory information of the vibrating rod includes the following steps: S100, deploy UWB base stations, UWB transmitters and IMU sensors.

[0030] At least four UWB base stations are required to achieve three-dimensional positioning. Increasing the number of UWB base stations can enhance anti-interference capabilities and provide redundancy. The height of the UWB base station is 0.5m-2.5m higher than the target to reduce the transmission blind area.

[0031] In this embodiment, four UWB base stations are used as an example. The layout of the UWB base stations is as follows: Figure 2 As shown in the figure, the four UWB base stations are divided into two groups, set up in pairs. The UWB base stations in the same group are set at the diagonal top surface of the box beam mold, and the heights of the UWB base stations in different groups are different. According to the application scenario, the distance between the base stations is controlled within the effective ranging range, and obstacles are avoided as much as possible to reduce multipath and non-line-of-sight propagation.

[0032] Specifically, there are four UWB base stations, namely UWB base station 1, UWB base station 2, UWB base station 3 and UWB base station 4, distributed at the four corners of the box girder. UWB base station 1 and UWB base station 3 are a group, 2.5m above the top surface of the box girder, and UWB base station 2 and UWB base station 4 are a group, 0.5m above the top surface of the box girder.

[0033] UWB base stations can be deployed in a symmetrical distribution form such as a tetrahedron or a cone to avoid the uncertainty caused by the coplanarity of the base stations.

[0034] The UWB transmitter is fixed at the connection between the vibration end of the vibrating rod and the hose. In this embodiment, the method of sticking it on the outer wall of the hose is adopted, which is convenient for quickly installing the UWB transmitter and detaching the UWB transmitter from the hose after use. The IMU sensor is fixed at the vibration end, specifically the end of the vibration end close to the hose, as close to the UWB transmitter as possible. The data cables of the UWB transmitter and the IMU sensor are arranged in the hose and connected to the DTU. The DTU is connected to the server through a mobile network and an industrial-grade 485 bus, so that the data output by the UWB transmitter and the IMU sensor can be received by the server.

[0035] Due to the harsh concrete environment, it is necessary to set up protective design for the installation of UWB transmitters and IMU sensors, including dust-proof, moisture-proof, impact-proof and other protection measures, and regularly check the working status, calibration and troubleshooting.

[0036] S200, calculates the position and posture of the vibrating rod in the box beam mold through the positioning algorithm.

[0037] The positioning algorithm can be specifically a trilateration positioning algorithm or a multilateration positioning algorithm. The flowchart of the positioning algorithm is as follows: Figure 3As shown. In this embodiment, a trilateral measurement positioning algorithm is specifically used to calculate the distance between the vibrator and the UWB base station by measuring the signal transmission time between the vibrator and at least three UWB base stations. A three-dimensional space coordinate system is constructed, and the distance between the vibrator and the three UWB base stations is converted into a nonlinear equation group in the three-dimensional space coordinate system, which is solved by the Gauss-Newton iteration method to obtain the estimated value of the precise coordinates of the vibrator in the three-dimensional space coordinate system.

[0038] As the UWB transmitter goes deeper into the concrete in the box beam mold, the UWB signal that can be received by the UWB base station gradually weakens. At this time, the estimated value of the precise coordinates of the vibrator obtained by calculation has a large error, making it difficult to locate the position of the vibrator in the box beam mold. Therefore, by setting a preset value, when the signal strength of the UWB transmitter is less than or equal to the preset value, the positioning algorithm will also combine the lossless Kalman filter algorithm to correct the estimated value.

[0039] Specifically, a state space model containing state variables such as position, velocity, and attitude is established through a lossless Kalman filter algorithm. The state variables are updated in real time through the distance obtained by the UWB base station to obtain the measurement value. The state of the vibrator is then predicted based on the acceleration and angular velocity measured by the IMU sensor. The lossless Kalman gain is then calculated, and the measurement value corrected by the lossless Kalman filter algorithm is losslessly fused with the estimated value to obtain a more accurate positioning of the precise coordinates of the vibrator, thereby making a more accurate judgment on the position and attitude of the vibrator.

[0040] By continuously acquiring the data output by the UWB transmitter and IMU sensor in real time, the position and posture of the vibrator in three-dimensional space are calculated in real time, and the real-time and accurate motion trajectory of the vibrator is obtained, so as to realize real-time and accurate response to the position change of the vibrator during the concrete pouring process.

[0041] The sliding window N is set, and the data of the current moment and the previous N-1 moments are weighted averaged. The result of the weighted average is the optimal output value at the current moment. The weight can be set to a Gaussian kernel function that decays with time. The estimated value corrected by the lossless Kalman filter algorithm is further de-noised by the weighted sliding average algorithm, which enhances the stability of the obtained motion trajectory of the vibrator and makes the rolling trajectory smoother.

[0042] S300, vibration status analysis.

[0043] According to the motion trajectory, speed and vibration law of the vibrating rod, the vibration time of the vibrating rod at each position and the cumulative vibration time of the entire vibration process of the vibrating rod are calculated and recorded, thereby achieving accurate recording of the time nodes and duration of the vibration process.

[0044] The data output by the IMU sensor of the historical vibrator is divided into two groups: empty vibration state data and actual vibration state data. The empty vibration state data and actual vibration state data are used as the input of the bidirectional LSTM neural network model for model training. By using the data output by the IMU sensor obtained by actual detection as the input of the trained bidirectional LSTM neural network model, the vibration state of the concrete is analyzed according to the vibration time, vibration area, and overlap degree of the vibration area of ​​the vibrator, such as insufficient vibration, normal vibration, and excessive vibration.

[0045] The motion trajectory of the vibrating rod, vibration time, vibration range and vibration status of the concrete are displayed in real time on the host computer or display screen through three-dimensional rendering technologies such as Three.js, so that construction personnel can monitor the vibration status of the concrete in real time and adjust the vibration plan according to the vibration status.

[0046] Specifically, taking Three.js and box beam as an example, a 3D model of the box beam is constructed with the help of Three.js, and the motion trajectory of the vibrator in the box beam is dynamically rendered over time. Three.js also supports multi-angle and multi-view interactive operations, making it easier to have a more intuitive and accurate understanding of the motion trajectory of the vibrator.

[0047] Then, through real-time communication technologies such as WebSocket and other communication connections with servers, the vibration process of the vibrating rod is displayed in real time. Combined with the recognition results output by the bidirectional LSTM neural network model, different colors are used to represent the vibration status on the box girder model, such as: light gray represents insufficient vibration areas, medium gray represents qualified vibration areas, dark gray represents excessive vibration areas, and white areas represent missed vibration areas that have not achieved effective vibration. When a missed vibration area is detected, the missed vibration area will be highlighted and flashed on the box girder model and an alarm will be issued.

[0048] It should be noted that the measurement method of the present invention that can track and record the movement trajectory information of the vibrating rod is not limited to the casting of box girders, but can also be used in other fields such as concrete casting of construction projects and bridge engineering. When the vibration state is visualized, the vibration time of the vibrating rod at different times and positions, as well as the total vibration time of the overlapping parts of the vibration range, can also be displayed, which is convenient for construction personnel to plan the vibration plan.

[0049] The above are all preferred embodiments of the present invention, and are not intended to limit the protection scope of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A measurement method capable of tracking and recording the motion trajectory information of a vibrating rod, characterized in that: The steps include: At least four UWB base stations are deployed, with the UWB transmitter fixed at the connection between the vibrating end of the vibrating rod and the hose, and the IMU sensor fixed at the vibrating end of the vibrating rod; According to the data output by the UWB transmitter and the IMU sensor, the position and posture of the vibrator in the measured target are calculated through the positioning algorithm, and the motion trajectory of the vibrator is further calculated; The vibration state of concrete is analyzed based on the vibration time, vibration area, and degree of overlap of the vibration area of ​​the vibrating rod.

2. The measuring method capable of tracking and recording the motion trajectory information of the vibrating rod according to claim 1, characterized in that: After completing the analysis of the concrete vibration status, different vibration status are marked with different colors on the model of the measured target.

3. The measuring method capable of tracking and recording the motion trajectory information of the vibrating rod according to claim 1, characterized in that: The UWB base station is 0.5m-2.5m higher than the target being measured.

4. The measuring method capable of tracking and recording the motion trajectory information of the vibrating rod according to claim 1, characterized in that: The positioning algorithms include trilateration positioning algorithm and multilateration positioning algorithm.

5. The measuring method capable of tracking and recording the motion trajectory information of the vibrating rod according to claim 1, characterized in that: The method for calculating the position of the vibrator in the measured object comprises the following steps: Measure the signal transmission time between the vibrator and any three UWB base stations, and further calculate the distance between the vibrator and the UWB base station; Construct a three-dimensional space coordinate system, and transform the distance between the vibrator and the three UWB base stations into a nonlinear equation system in the three-dimensional space coordinate system; By solving the nonlinear equations, the estimated values ​​of the precise coordinates of the vibrating rod in the three-dimensional space coordinate system are obtained.

6. The measuring method capable of tracking and recording the motion trajectory information of the vibrating rod according to claim 5, characterized in that: When the signal strength of the UWB transmitter is less than or equal to the preset value, a state space model containing state variables of position, velocity and attitude is established through a lossless Kalman filter algorithm; The distance obtained by the UWB base station is used to update the state variables in real time to obtain the measurement value; The state of the vibrator is predicted based on the acceleration and angular velocity measured by the IMU sensor; Calculate the lossless Kalman gain and correct the measured value; The measured values ​​and estimated values ​​are non-destructively fused to obtain the precise coordinate positioning of the vibrating rod in the three-dimensional space coordinate system.

7. The measuring method capable of tracking and recording the motion trajectory information of the vibrating rod according to claim 6, characterized in that: By continuously acquiring the data output by the UWB transmitter and the IMU sensor, the motion trajectory of the vibrator is calculated; Set the sliding window N, and perform weighted average calculation on the data at the current moment and the previous N-1 moments. The result after weighted average is the optimal output value at the current moment, and the positioning is denoised; The weights are in the form of a Gaussian kernel function that increases and decays over time.

8. The measuring method capable of tracking and recording the motion trajectory information of the vibrating rod according to claim 1, characterized in that: Before analyzing the vibration state of concrete, the historical IMU sensor output data is divided into empty vibration state data and real vibration state data; The empty vibration state data and the actual vibration state data are used as the input of the bidirectional LSTM neural network model, and the vibration state of the concrete is used as the output for model training. The bidirectional LSTM neural network model that has completed model training is used to judge the current vibration state of concrete.

9. The measuring method capable of tracking and recording the motion trajectory information of the vibrating rod according to claim 1, characterized in that: The vibration time of the vibrating rod includes the vibrating time of the vibrating rod at each position and the cumulative vibration time of the entire vibrating process of the vibrating rod.

10. The measuring method capable of tracking and recording the motion trajectory information of the vibrating rod according to claim 1, characterized in that: When analyzing the vibration state of concrete, the vibration time of the vibrating rod at different times and positions, as well as the total vibration time of the overlapping part of the vibration range, are displayed on the model of the measured target.

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