A method and system for detecting the travel position of an object in a closed cavity

Abstract

The present invention discloses a method and system for detecting the travel position of an object in a closed cavity, and relates to the field of detecting the travel position of an object in an industrial closed cavity of a thermal power plant. The detection method comprises the following steps: S1, installing a plurality of evenly distributed magnetic switches on the outer wall of the closed cavity as detection nodes, and marking the positions and node numbers; S2, in the detection process of a movable object in the closed cavity, calculating the equivalent current signal of the equivalent circuit model in real time by Ohm's law; S3, converting the equivalent current signal obtained by real-time detection and the contact change information into a signal format; S4, establishing a virtual environment of the closed cavity based on digital twin technology, and then using the motion model of the movable object for position positioning. The present invention realizes real-time positioning of the object position by establishing a virtual environment and a motion model, provides intuitive and accurate information to operators, and is helpful for intelligent decision-making and system optimization.

Description

Technical Field

[0001] The invention relates to the field of object travel position detection in an industrial closed chamber of a thermal power plant, and in particular to a method and system for detecting the travel position of an object in a closed chamber. Background Art

[0002] In the thermal power plant industry, pneumatic actuators, as key control devices, play an indispensable role in the operation of thermal power plants. These mechanisms are widely used to control valves, actuators, and other key equipment to ensure the safe operation and efficient power generation of thermal power plants. Especially in linear pneumatic actuators, the actual position of its internal structure in the closed chamber is crucial to the overall production situation.

[0003] However, in the actual operation of thermal power plants, the closed and complex environment of pneumatic actuators in mechanical factories brings a series of challenges. Among them, one of the most significant challenges is how to effectively monitor the position of the mechanism along the process. At present, thermal power plants can usually only detect the end limit position through infrared switches installed at the end, but the position of the mechanism along the process of movement cannot be directly obtained. This means that in daily production processes, once the pneumatic actuator is stuck, damaged or other abnormal conditions occur, engineers will not be able to quickly obtain the accurate position information of the internal structure, and thus will not be able to respond in time, resulting in production interruptions, equipment failures and potential safety risks.

[0004] Therefore, how to effectively monitor the position of the pneumatic actuator along the stroke and respond promptly to abnormal situations such as jamming or damage to ensure the normal operation of the equipment. To solve this problem, engineers actively explore various advanced monitoring technologies and intelligent control strategies.

[0005] For example, high-precision position sensors, such as linear displacement sensors or magnetic encoders, are installed in closed cavities to accurately measure the actual position of pneumatic actuators, or vibration sensors or acceleration sensors are introduced to monitor the vibration of the mechanism and detect potential problems in advance. A remote monitoring and diagnostic system is then established to transmit the operating data of the mechanism to the cloud or remote server to achieve remote real-time monitoring and data analysis. However, high-precision sensors and advanced monitoring systems are usually accompanied by high costs. The deployment and maintenance of advanced monitoring systems and sensor networks require professional knowledge, which increases the complexity of the system and requires staff to be trained to adapt to new technologies. In addition, the long-term use of sensors in harsh environments may face reliability issues. For example, high temperature, high humidity and other conditions may affect the equipment. Therefore, how to reduce the cost and technical difficulty of object detection in closed cavities and intuitively and clearly check the travel position of internal objects is still a technical problem that needs to be solved urgently. Summary of the invention

[0006] Based on this, it is necessary to provide a method and system for detecting the travel position of an object in a closed cavity in order to address the above technical problems.

[0007] In a first aspect, the present invention provides a method for detecting the travel position of an object in a closed cavity, the detection method comprising the following steps:

[0008] S1. Install multiple evenly distributed magnetic switches on the outer wall of the closed cavity as detection nodes, mark the positions and node numbers, and then construct a control loop and its equivalent circuit model in parallel;

[0009] S2. During the detection of a movable object in a closed cavity, the equivalent current signal of the equivalent circuit model is calculated in real time by Ohm's law, and the contact changes of the detection node are recorded;

[0010] S3, converting the equivalent current signal and contact change information obtained by real-time detection into signal formats, and sending them to a signal receiver in the management center by wireless communication;

[0011] S4. Based on the digital twin technology, a virtual environment of a closed cavity is established. The motion model of the movable object is then used for positioning and imported into the virtual environment for visual display.

[0012] Furthermore, the number of magnetic switches is n, the spacing between two adjacent magnetic switches is equal, the two magnetic switches at both ends are arranged on the two end faces of the closed cavity, the n magnetic switches divide the closed cavity into m closed spaces, and m=n-1, and the space number is marked for each closed space in the order of the node number.

[0013] Furthermore, in the process of detecting a movable object in a closed cavity, the equivalent current signal of the equivalent circuit model is calculated in real time by Ohm's law, and the contact change of the magnetic switch is recorded, including the following steps:

[0014] S21, recording an initial equivalent current signal of the movable object before it moves;

[0015] S22, when the movable object moves, each time it passes a detection node, the magnetic switch corresponding to the detection node is converted from normally open to normally closed or from normally closed to normally open, and at this time, the real-time equivalent current signal of the equivalent circuit model is calculated by Ohm's law;

[0016] S23. Based on the numerical change information of the real-time equivalent current signal, determine the contact change of the magnetic switch corresponding to the detection node that the current movable object has passed most recently, and record the node number of the detection node and the space number of the closed space where the current movable object is located.

[0017] Furthermore, the magnetic switch is a circuit switch device controlled by a magnetic field signal. When the magnetic switch senses the passage of a movable object in a closed cavity, the contact drawn by the magnetic switch is converted from normally open to normally closed or from normally closed to normally open;

[0018] The control loop is a closed loop formed by connecting all magnetic switches in parallel, and then an equivalent circuit model is formed by configuring the supply voltage and the resistance value of each magnetic switch.

[0019] Furthermore, a virtual environment of a closed cavity is established based on the digital twin technology, and then the motion model of the movable object is used for position positioning, and the virtual environment is imported for visualization display, including the following steps:

[0020] S41. Using digital twin technology to construct a digital twin based on the physical parameters of the closed cavity, and integrating virtual detection nodes and virtual movable objects to form a virtual environment;

[0021] S42, using the timestamp information to calculate the speed of the movable object, and then establishing a motion model of the movable object based on an exponential smoothing prediction model to predict the current travel position information;

[0022] S43, importing the travel position information of the movable object into the virtual environment for visual display, and then continuing to calculate the travel position information at the next moment for real-time dynamic update;

[0023] S44: Verify the predicted travel position information using the actual position information corresponding to the next timestamp information to determine whether the travel position of the movable object meets the travel standard.

[0024] Furthermore, the speed of the movable object is calculated using the timestamp information, and then a motion model of the movable object is established based on the exponential smoothing prediction model to predict the current travel position information, including the following steps:

[0025] S421, obtaining timestamp information of a contact point change of each detection node during the wireless communication process, and marking the corresponding contact point change time according to the node sequence number of the detection node;

[0026] S422, calculating the interval between the latest contact change time and the previous contact change time, and dividing the interval time into five equal parts, each of which is a moving moment;

[0027] S423, establishing a motion model based on an exponential smoothing prediction model, predicting the motion trend of the movable object, and estimating the predicted position information of the movable object at the next moving moment;

[0028] S424, calculating the correction weight of the predicted position information by using the actual speed and the predicted speed, and then using the correction weight to correct the predicted position information of the movable object at the current moving moment to obtain the final travel position information.

[0029] Furthermore, a motion model is established based on the exponential smoothing prediction model to predict the motion trend of the movable object, and estimating the position information of the movable object at the next moving moment includes the following steps:

[0030] S4231, obtaining an initial speed of the movable object entering the closed cavity, where the initial speed is also the speed when the movable object passes through the first detection node;

[0031] S4232, when the movable object passes through the current detection node, using the interval time between the current contact change time and the previous contact change time, and the length of the closed space between the two detection nodes, calculate the acceleration of the movable object in the closed space and the actual speed when passing through the next detection node;

[0032] S4233, setting the movement of the movable object in the same closed space as uniformly accelerated movement, and calculating the position coordinates of the movable object at each moving moment according to the node sequence number and position information of the detection node that the movable object has recently passed;

[0033] S4234, obtaining the position coordinates of the movable object at the first five moving moments, setting the exponential smoothing value, and establishing an exponential smoothing calculation formula, which is:

[0034]

[0035] In the formula, Represents the exponential smoothing value at the t-th moving moment; represents the exponential smoothing value at the t-1th moving moment; Y t＋1 represents the predicted position at the t+1th moving moment; Y t represents the predicted position at the tth moving moment; α represents the smoothing coefficient;

[0036] S4235, estimating the predicted speed of the movable object at the current moving moment by a first-order exponential smoothing calculation formula, the calculation formula of the predicted speed is:

[0037]

[0038] In the formula, v t represents the predicted speed of the movable object at the tth moving moment; v max Indicates the maximum speed of the movable object in the first five moving moments; (x t ,y t) represents the position coordinates of the movable object at the tth moving moment; (x t-1 ,y t-1 ) represents the position coordinates of the movable object at the t-1th moving moment;

[0039] S4236: Taking the product of the predicted speed of the movable object at the current moment and the moving moment as the moving distance, the predicted position information of the movable object at the current moment is estimated.

[0040] Furthermore, the correction weight of the predicted position information is calculated by the actual speed and the predicted speed, and then the predicted position information of the movable object at the current moving moment is corrected by using the correction weight to obtain the final travel position information, including the following steps:

[0041] S4241, obtaining the actual speed of the currently passed detection node calculated by the current contact change time and the previous contact change time, and then obtaining the predicted speed at the moving moment corresponding to the current contact change time calculated by a first exponential smoothing calculation formula, and calculating the angle between the actual speed and the predicted speed;

[0042] S4242, using the reciprocal of the angle as a correction weight for the predicted position information;

[0043] S4243, using the correction weight to correct the predicted position information, to obtain the travel position information of the movable object in the closed cavity at the current moving moment, the correction formula is:

[0044]

[0045] In the formula, (x i ,y i ) represents the predicted position information of the movable object in the closed cavity at the i-th moving moment; (x c ,y c ) represents the travel position information of the movable object in the closed cavity; N represents the number of moving moments; w i Represents the correction weight corresponding to the i-th moving moment.

[0046] Further, the predicted travel position information is verified using the actual position information corresponding to the next timestamp information to determine whether the travel position of the movable object meets the travel standard. The following steps are performed:

[0047] S441, obtaining a contact point change time corresponding to the next timestamp information, at which time the travel position of the movable object is at a detection node corresponding to the contact point change time;

[0048] S442. Search for the moving moment that is at the same time as the contact change time in the predicted travel position information, and obtain the travel position information predicted by the moving moment, and compare the travel position information with the actual detection node position information. If the difference between the two is less than the standard distance, it is determined that the travel position prediction of the movable object meets the travel standard. If the difference between the two is greater than or equal to the standard distance, it is determined that the travel position prediction of the movable object does not meet the travel standard, and the detection node at this time is used as the initial node to re-predict the position.

[0049] In a second aspect, the present invention further provides a detection system for the travel position of an object in a closed cavity, the detection system comprising: an equivalent circuit model module, a closed cavity detection module, a wireless communication transmission module and a positioning identification display module, wherein:

[0050] The equivalent circuit model module is used to install multiple evenly distributed magnetic switches on the outer wall of the closed cavity as detection nodes, mark the positions and node numbers, and then construct a control loop and its equivalent circuit model in parallel;

[0051] A closed cavity detection module is used to calculate the equivalent current signal of the equivalent circuit model in real time through Ohm's law during the detection process of a movable object in a closed cavity, and record the contact changes of the detection node;

[0052] A wireless communication transmission module is used to convert the equivalent current signal and contact change information obtained by real-time detection into a signal format, and send them to a signal receiver in the management center by wireless communication;

[0053] The positioning, identification and display module is used to establish a virtual environment of a closed cavity based on digital twin technology, and then use the motion model of the movable object to locate the position and import it into the virtual environment for visual display.

[0054] The beneficial effects of the present invention are:

[0055] 1. Through the uniform distribution and marking of magnetic switches, high-precision monitoring of the travel position of movable objects in a closed cavity is achieved. The equivalent current signal of the equivalent circuit model is calculated in real time using Ohm's law, and the contact changes of the detection nodes are accurately recorded, thereby improving the accuracy of detection. The introduction of digital twin technology achieves real-time positioning of the object position by establishing a virtual environment and motion model, providing operators with intuitive and accurate information, which is helpful for intelligent decision-making and system optimization, thereby improving monitoring accuracy and realizing remote management, providing advanced and feasible solutions for intelligent monitoring and management in the industrial field.

[0056] 2. By building a virtual environment of a closed cavity through digital twin technology, the actual physical parameters can be accurately simulated, providing a reliable basis for subsequent positioning. The virtual detection nodes and virtual movable objects are integrated to realize the full simulation of the movement of objects in the actual environment, improve the simulation accuracy of the virtual environment, calculate the speed of the movable object through timestamp information, and establish a motion model using the exponential smoothing prediction model to achieve accurate prediction of the travel position, providing an efficient means for real-time positioning, and providing advanced and effective technical means for real-time monitoring, remote operation and intelligent decision-making in the industrial field. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of the present invention. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

[0058] Figure 1 is a flow chart of a method for detecting the travel position of an object in a closed cavity according to an embodiment of the present invention;

[0059] Figure 2 is a schematic diagram of a closed cavity, a magnetic switch and a movable object in a method for detecting a travel position of an object in a closed cavity according to an embodiment of the present invention;

[0060] Figure 3 It is a schematic diagram of the circuit principle of an equivalent circuit model in a method for detecting the travel position of an object in a closed cavity according to an embodiment of the present invention;

[0061] Figure 4 The present invention is a system principle block diagram of a system for detecting the travel position of an object in a closed cavity according to an embodiment of the present invention.

[0062] Figure numbers: 1. Equivalent circuit model module; 2. Closed cavity detection module; 3. Wireless communication transmission module; 4. Positioning identification display module. DETAILED DESCRIPTION

[0063] In order to make the purpose, technical solution and advantages of the present invention more clearly understood, the present invention is further described in detail below in conjunction with the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.

[0064] See also Figure 1-Figure 3 A method for detecting the travel position of an object in a closed cavity, the detection method comprising the following steps:

[0065] S1. Install multiple evenly distributed magnetic switches on the outer wall of the closed cavity as detection nodes, mark the positions and node numbers, and then construct the control loop and its equivalent circuit model in parallel.

[0066] In the description of the present invention, the number of magnetic switches is n, the spacing between two adjacent magnetic switches is equal, the two magnetic switches located at both ends are arranged on the two end faces of the closed cavity, the n magnetic switches divide the closed cavity into m closed spaces, and m=n-1, and the space number is marked for each closed space in the order of the node number.

[0067] like Figure 2 As shown, it is assumed that there are five magnetic switches outside the closed cavity, including magnetic switches 1(a), 1(b), 1(c), 1(d), and 1(e), and there is a movable object structure (A) inside the closed cavity (B). The measurement of the travel position of the object in the closed cavity is completed through the control loop.

[0068] The magnetic switch is a circuit switch device controlled by a magnetic field signal. When the magnetic switch senses the passage of a movable object in a closed cavity, the contact drawn by the magnetic switch changes from normally open to normally closed or from normally closed to normally open, and its action contact is a single contact (Kx). The magnetic switch is evenly distributed and installed on the outer wall of the closed cavity. Its contact is an iron sleeve that can withstand a pressure of 0.6MPa in the closed cavity. It is sealed and leak-proof. The edge of the internal structure should be in close contact with the sleeve wall. The internal movable object structure should have an iron object that can be sensed by the magnetic switch to represent its position.

[0069] The control loop is a closed loop formed by connecting all magnetic switches in parallel, and then an equivalent circuit model is formed by configuring the supply voltage and the resistance value of each magnetic switch, such as Figure 3 shown.

[0070] S2. During the detection of a movable object in a closed cavity, the equivalent current signal of the equivalent circuit model is calculated in real time by Ohm's law, and the contact changes of the detection node are recorded.

[0071] In the description of the present invention, in the process of detecting a movable object in a closed cavity, the equivalent current signal of the equivalent circuit model is calculated in real time by Ohm's law, and the contact change of the magnetic switch is recorded, which includes the following steps:

[0072] S21. Recording the initial equivalent current signal of the movable object before it moves.

[0073] S22. When the movable object moves, each time it passes a detection node, the magnetic switch corresponding to the detection node is converted from normally open to normally closed or from normally closed to normally open. At this time, the real-time equivalent current signal of the equivalent circuit model is calculated by Ohm's law.

[0074] The equivalent circuit model is based on Ohm's law. The equivalent circuit of a parallel circuit is equal to the sum of the reciprocals of each resistance, that is, the more resistors are connected in parallel, the smaller the equivalent resistance is. Therefore, the magnetic switch is evenly distributed outside the closed cavity from the initial position to the end position, and its lead-out contact Kx is introduced into the control circuit. A resistor RX is connected in series behind the contact. When the internal movable object structure passes through the magnetic switch 1(x), the contact is closed and the parallel resistance increases.

[0075] Take the case of connecting to a power supply voltage of 24V and distributing five magnetic switches outside the closed cavity as an example, the resistance Rx = 6KΩ, then when the internal movable object structure is in the initial position, the contact of magnetic switch 1(a) is closed, and the current of the total circuit is When the internal movable object structure moves to 25% of the overall length and passes through the magnetic switch 1 (b), the total circuit resistance R2 = 3KΩ, and the total current is Similarly, when the internal movable object structure moves to the end position, that is, the overall length is 100%, the total circuit resistance R5 = 1.2KΩ, and the total current is Through this method, the travel position of an object in a closed cavity can be converted into a 4-20mA current signal through a circuit, which can then be received by a card in the control system and displayed on the upper computer screen for monitoring operations by the monitoring personnel.

[0076] S23. Based on the numerical change information of the real-time equivalent current signal, determine the contact change of the magnetic switch corresponding to the detection node that the current movable object has passed most recently, and record the node number of the detection node and the space number of the closed space where the current movable object is located.

[0077] S3. Convert the equivalent current signal and contact change information obtained by real-time detection into signal formats, and send them to the signal receiver of the management center by wireless communication.

[0078] In the description of the present invention, the equivalent current signal and contact change information obtained by real-time detection usually exist in the form of analog signals, and need to be formatted for transmission and processing. Involving processes such as analog-to-digital conversion (A / D conversion), the analog signal is converted into a digital signal for better processing, transmission and storage. The digitized signal is easier to encode, compress and decode, which improves the stability and anti-interference of the signal. The converted digital signal and the contact change information are organized into a data packet. Data packet encapsulation usually includes adding header information (Header) to identify the type, length and other information of the data packet, and a check code to detect the integrity of data transmission.

[0079] Select an appropriate wireless communication protocol for data transmission. Common wireless communication protocols include Wi-Fi, Bluetooth, Zigbee, LoRa, etc. Select the appropriate communication protocol according to the specific application scenario and requirements. Each protocol has its own unique characteristics, such as transmission distance, energy consumption, data transmission rate, etc., which need to be weighed according to the actual situation. The encapsulated data packets are sent to the signal receiver of the management center through the wireless communication module, which involves hardware devices such as wireless transmitters and antennas, which are used to convert digital signals into electromagnetic waves and transmit them wirelessly.

[0080] A signal receiver is set up in the management center to receive the wireless signal from the monitoring node. The receiver decodes and decapsulates the received signal to obtain the original digital signal and contact change information.

[0081] S4. Based on the digital twin technology, a virtual environment of a closed cavity is established. The motion model of the movable object is then used for positioning and imported into the virtual environment for visual display.

[0082] In the description of the present invention, a virtual environment of a closed cavity is established based on digital twin technology, and then a motion model of a movable object is used for position positioning, and the virtual environment is imported for visual display, including the following steps:

[0083] S41. Use digital twin technology to construct a digital twin based on the physical parameters of the closed cavity, and integrate virtual detection nodes and virtual movable objects to form a virtual environment.

[0084] Collect the physical parameters of the closed cavity, including the geometry, material properties, temperature, humidity and other related parameters of the closed cavity. These physical parameters directly affect the authenticity and accuracy of the virtual environment for the modeling of the digital twin. Use the collected physical parameters to establish a mathematical model of the closed cavity, including the use of physical equations, mathematical models or computational fluid dynamics (CFD) and other methods to describe the physical processes such as fluid movement and heat conduction in the closed cavity.

[0085] Virtual detection nodes are integrated into the digital twin, and the virtual detection nodes simulate the location, characteristics and working principle of the actual detection nodes, so as to simulate the travel position monitoring in the virtual environment. Virtual movable objects are integrated into the digital twin, and the objects simulate the movement, travel position and other parameters of movable objects in the closed cavity, and the real-time update of their status is achieved through digital twin technology.

[0086] Based on the mathematical model, the digital twin technology is used to construct the digital twin of the closed cavity. The digital twin is a digital mapping of the physical system, which simulates the behavior of the real system and allows real-time updates to reflect changes in the actual environment, including digital modeling of the internal structure, temperature distribution, fluid movement, etc. of the closed cavity.

[0087] S42, using the timestamp information to calculate the speed of the movable object, and then establishing a motion model of the movable object based on the exponential smoothing prediction model to predict the current travel position information.

[0088] In the description of the present invention, the speed of the movable object is calculated using the timestamp information, and then the motion model of the movable object is established based on the exponential smoothing prediction model to predict the current travel position information, which includes the following steps:

[0089] S421. Acquire timestamp information of a contact point change of each detection node during wireless communication, and mark the corresponding contact point change time according to the node sequence number of the detection node.

[0090] S422, calculating the interval time between the latest contact change time and the previous contact change time, and dividing the interval time into five equal parts, each of which is a moving moment.

[0091] S423: Establish a motion model based on the exponential smoothing prediction model, predict the motion trend of the movable object, and estimate the predicted position information of the movable object at the next moving moment.

[0092] Among them, the exponential smoothing forecasting model is a time series analysis method, which is mainly used to predict future data. This model is based on the weighted average of past observations, giving higher weights to recent data and gradually reducing the weights to better adapt to the trends and seasonality of the data.

[0093] In the description of the present invention, a motion model is established based on an exponential smoothing prediction model to predict the motion trend of a movable object, and estimating the position information of the movable object at the next moving moment includes the following steps:

[0094] S4231. Obtain an initial velocity of the movable object entering the closed cavity, where the initial velocity is also the velocity when passing through the first detection node.

[0095] S4232. When the movable object passes through the current detection node, the acceleration of the movable object in the closed space and the actual speed when passing through the next detection node are calculated by using the interval time between the current contact change time and the previous contact change time and the length of the closed space between the two detection nodes. Some variables can be set according to the above parameters:

[0096] v0: initial speed, which is also the speed when passing the first detection node.

[0097] t1: The contact change time when passing the current detection node.

[0098] t0: The time when the previous contact changes.

[0099] L: The length of the closed space between two detection nodes.

[0100] a: Acceleration in a single enclosed space.

[0101] v1: The actual speed when passing the next detection node.

[0102] Δt: The interval time between two contact change times.

[0103] The acceleration can then be calculated using the formula:

[0104] Next, by substituting the acceleration into the first kinematics formula, the actual velocity when passing the next detection node can be calculated:

[0105] Through the above steps, the acceleration of the movable object in the closed cavity and the actual speed when passing the next detection node can be calculated according to the contact change time, interval time and the length of the closed space. However, it is necessary to assume that the motion between the two detection nodes is uniformly accelerated linear motion.

[0106] S4233, setting the movement of the movable object in the same closed space as uniformly accelerated motion, and calculating the position coordinates of the movable object at each moving moment according to the node sequence number and position information of the detection node that the movable object has recently passed.

[0107] S4234, obtaining the position coordinates of the movable object at the first five moving moments, setting the exponential smoothing value, and establishing an exponential smoothing calculation formula, which is:

[0108]

[0109] In the formula, represents the exponential smoothing value at the t-th moving moment, represents the exponential smoothing value at the t-1th moving moment, Y t+1 represents the predicted position at the t+1th moving moment, Y t represents the predicted position at the tth moving moment, and α represents the smoothing coefficient.

[0110] S4235, estimating the predicted speed of the movable object at the current moving moment by a first-order exponential smoothing calculation formula, the calculation formula of the predicted speed is:

[0111]

[0112] In the formula, v t represents the predicted speed of the movable object at the tth moving moment, v max represents the maximum speed of the movable object in the first five moving moments, (x t ,y t ) represents the position coordinates of the movable object at the tth moving moment, (x t-1 ,y t-1 ) represents the position coordinates of the movable object at the t-1th moving moment.

[0113] S4236: Taking the product of the predicted speed of the movable object at the current moment and the moving moment as the moving distance, the predicted position information of the movable object at the current moment is estimated.

[0114] S424, calculating the correction weight of the predicted position information by using the actual speed and the predicted speed, and then using the correction weight to correct the predicted position information of the movable object at the current moving moment to obtain the final travel position information.

[0115] In the description of the present invention, the correction weight of the predicted position information is calculated by the actual speed and the predicted speed, and then the predicted position information of the movable object at the current moving moment is corrected by the correction weight to obtain the final travel position information, which includes the following steps:

[0116] S4241. Obtain the actual speed of the currently passed detection node calculated by the current contact change time and the previous contact change time, then obtain the predicted speed at the moving moment corresponding to the current contact change time calculated by a first exponential smoothing calculation formula, and calculate the angle between the actual speed and the predicted speed.

[0117] S4242. Use the reciprocal of the angle as a correction weight for the predicted position information.

[0118] S4243, using the correction weight to correct the predicted position information, to obtain the travel position information of the movable object in the closed cavity at the current moving moment, the correction formula is:

[0119]

[0120] In the formula, (x i ,y i ) represents the predicted position information of the movable object in the closed cavity at the i-th moving moment, (x c ,y c ) represents the travel position information of the movable object in the closed cavity, N represents the number of moving moments, and wi Represents the correction weight corresponding to the i-th moving moment.

[0121] S43, importing the travel position information of the movable object into the virtual environment for visual display, and then continuing to calculate the travel position information at the next moment for real-time dynamic update.

[0122] S44: Verify the predicted travel position information using the actual position information corresponding to the next timestamp information to determine whether the travel position of the movable object meets the travel standard.

[0123] In the description of the present invention, the predicted travel position information is verified using the actual position information corresponding to the next timestamp information to determine whether the travel position of the movable object meets the travel standard. The following steps are performed:

[0124] S441, obtaining a contact point change time corresponding to the next timestamp information, at which time the travel position of the movable object is at a detection node corresponding to the contact point change time.

[0125] S442. Search for the moving moment that is at the same time as the contact change time in the predicted travel position information, and obtain the travel position information predicted by the moving moment, and compare the travel position information with the actual detection node position information. If the difference between the two is less than the standard distance, it is determined that the travel position prediction of the movable object meets the travel standard. If the difference between the two is greater than or equal to the standard distance, it is determined that the travel position prediction of the movable object does not meet the travel standard, and the detection node at this time is used as the initial node to re-predict the position.

[0126] See also Figure 4 , and also provides a detection system for the travel position of an object in a closed cavity, the detection system comprising: an equivalent circuit model module 1, a closed cavity detection module 2, a wireless communication transmission module 3 and a positioning identification display module 4, wherein:

[0127] The equivalent circuit model module 1 is used to install a plurality of evenly distributed magnetic switches as detection nodes on the outer wall of the closed cavity, mark the positions and node numbers, and then construct a control loop and its equivalent circuit model in parallel.

[0128] The closed cavity detection module 2 is used to calculate the equivalent current signal of the equivalent circuit model in real time through Ohm's law during the detection process of the movable object in the closed cavity, and record the contact change of the detection node.

[0129] The wireless communication transmission module 3 is used to convert the equivalent current signal and the contact change information obtained by real-time detection into a signal format, and send them to the signal receiver of the management center by wireless communication.

[0130] The positioning, identification and display module 4 is used to establish a virtual environment of a closed cavity based on the digital twin technology, and then use the motion model of the movable object to locate the position, and import it into the virtual environment for visual display.

[0131] In summary, with the help of the above technical scheme of the present invention, through the uniform distribution and marking of the magnetic switch, high-precision monitoring of the stroke position of the movable object in the closed cavity is achieved, the equivalent current signal of the equivalent circuit model is calculated in real time by using Ohm's law, the contact change of the detection node is accurately recorded, and the accuracy of the detection is improved; the digital twin technology is introduced, and the real-time positioning of the object position is achieved by establishing a virtual environment and a motion model, providing intuitive and accurate information for operators, which is helpful for intelligent decision-making and system optimization, thereby improving the monitoring accuracy and realizing remote management, and providing an advanced and feasible solution for intelligent monitoring and management in the industrial field. By constructing a virtual environment of a closed cavity through digital twin technology, the actual physical parameters can be accurately simulated, providing a true and reliable basis for subsequent position positioning, integrating virtual detection nodes and virtual movable objects, realizing a full-scale simulation of the movement of objects in the actual environment, and improving the simulation accuracy of the virtual environment. The speed of the movable object is calculated by timestamp information, and the motion model is established by applying an exponential smoothing prediction model to achieve accurate prediction of the stroke position, providing an efficient means for real-time position positioning, and providing advanced and effective technical means for real-time monitoring, remote operation and intelligent decision-making in the industrial field.

[0132] It should be understood that, although the steps in the flowchart of the accompanying drawings are displayed in sequence as indicated by the arrows, these steps are not necessarily executed in sequence in the order indicated by the arrows. Unless otherwise specified herein, there is no strict order restriction on the execution of these steps, and they can be executed in other orders. Moreover, at least a part of the steps in the flowchart of the accompanying drawings may include multiple sub-steps or multiple stages, and these sub-steps or stages are not necessarily executed at the same time, but can be executed at different times, and their execution order is not necessarily sequential, but can be executed in turn or alternately with other steps or at least a part of the sub-steps or stages of other steps.

Claims

1. A method for detecting the travel position of an object in a closed cavity, characterized in that: The detection method comprises the following steps: S1. Install multiple evenly distributed magnetic switches on the outer wall of the closed cavity as detection nodes, mark the positions and node numbers, and then construct a control loop and its equivalent circuit model in parallel; S2. During the detection of the movable object in the closed cavity, the equivalent current signal of the equivalent circuit model is calculated in real time by Ohm's law, and the contact change of the detection node is recorded; S3, converting the equivalent current signal and contact change information obtained by real-time detection into signal formats, and sending them to a signal receiver in a management center by wireless communication; S4. Establish a virtual environment of the closed cavity based on the digital twin technology, then use the motion model of the movable object to locate the position, and import it into the virtual environment for visual display; The process of establishing a virtual environment of the closed cavity based on the digital twin technology, locating the position of the movable object using the motion model of the movable object, and importing the movable object into the virtual environment for visual display includes the following steps: S41. Using digital twin technology to construct a digital twin based on the physical parameters of the closed cavity, and integrating virtual detection nodes and virtual movable objects to form a virtual environment; S42, calculating the speed of the movable object using the timestamp information, and then establishing a motion model of the movable object based on an exponential smoothing prediction model to predict the current travel position information; S43, importing the travel position information of the movable object into the virtual environment for visual display, and then continuing to calculate the travel position information at the next moment for real-time dynamic update; S44: Verify the predicted travel position information using the actual position information corresponding to the next timestamp information to determine whether the travel position of the movable object meets the travel standard.

2. A method for detecting the travel position of an object in a closed cavity according to claim 1, characterized in that: The number of the magnetic switches is n, the spacing between two adjacent magnetic switches is equal, the two magnetic switches located at the two ends are arranged on the two end faces of the closed cavity, the n magnetic switches divide the closed cavity into m closed spaces, and m=n-1, and the space number is marked for each closed space in the order of the node number.

3. A method for detecting the travel position of an object in a closed cavity according to claim 2, characterized in that: In the process of detecting the movable object in the closed cavity, the equivalent current signal of the equivalent circuit model is calculated in real time by Ohm's law, and the contact change of the magnetic switch is recorded, which includes the following steps: S21, recording the initial equivalent current signal of the movable object before it moves; S22, when the movable object moves, each time it passes through a detection node, the magnetic switch corresponding to the detection node is converted from normally open to normally closed or from normally closed to normally open, and at this time, the real-time equivalent current signal of the equivalent circuit model is calculated by Ohm's law; S23. Based on the numerical change information of the real-time equivalent current signal, determine the contact change of the magnetic switch corresponding to the detection node that the current movable object has passed most recently, and record the node number of the detection node and the space number of the closed space where the current movable object is located.

4. A method for detecting the travel position of an object in a closed cavity according to claim 3, characterized in that: The magnetic switch is a circuit switch device controlled by a magnetic field signal. When the magnetic switch senses that a movable object passes through the closed cavity, the contact point drawn by the magnetic switch is converted from normally open to normally closed or from normally closed to normally open; The control loop is a closed loop formed by connecting all the magnetic switches in parallel, and an equivalent circuit model is formed by configuring the supply voltage and the resistance value of each magnetic switch.

5. A method for detecting the travel position of an object in a closed cavity according to claim 4, characterized in that: The method of calculating the speed of the movable object by using the timestamp information and then establishing a motion model of the movable object based on an exponential smoothing prediction model to predict the current travel position information comprises the following steps: S421, obtaining timestamp information of a contact point change of each detection node during wireless communication, and marking the corresponding contact point change time according to the node sequence number of the detection node; S422, calculating the interval between the latest contact change time and the previous contact change time, and dividing the interval into five equal parts, each of which is a moving moment; S423, establishing a motion model based on an exponential smoothing prediction model, predicting the motion trend of the movable object, and estimating the predicted position information of the movable object at the next moving moment; S424, calculating a correction weight of the predicted position information by using the actual speed and the predicted speed, and then using the correction weight to correct the predicted position information of the movable object at the current moving moment to obtain final travel position information.

6. A method for detecting the travel position of an object in a closed cavity according to claim 5, characterized in that: The method of establishing a motion model based on an exponential smoothing prediction model, predicting the motion trend of the movable object, and estimating the position information of the movable object at the next moving moment comprises the following steps: S4231, obtaining an initial speed of the movable object entering the closed cavity, where the initial speed is also the speed when passing through the first detection node; S4232: when the movable object passes through the current detection node, using the interval between the current contact change time and the previous contact change time and the length of the closed space between the two detection nodes, calculate the acceleration of the movable object in the closed space and the actual speed when passing through the next detection node; S4233, setting the movement of the movable object in the same closed space as uniformly accelerated movement, and calculating the position coordinates of the movable object at each moving moment according to the node sequence number and position information of the detection node that the movable object has passed most recently; S4234, obtaining the position coordinates of the movable object at the first five movement moments, setting the exponential smoothing value, and establishing an exponential smoothing calculation formula, which is: In the formula, Represents the exponential smoothing value at the t-th moving moment; Represents the exponential smoothing value at the t-1th moving moment; T t+1 represents the predicted position at the t+1th moving moment; Y t represents the predicted position at the tth moving moment; α represents the smoothing coefficient; S4235, estimating the predicted speed of the movable object at the current moving moment by the first exponential smoothing calculation formula, the calculation formula of the predicted speed is: In the formula, v t represents the predicted speed of the movable object at the tth moving moment; v max Indicates the maximum speed of the movable object in the first five moving moments; (x t ,y t ) represents the position coordinates of the movable object at the tth moving moment; (x t-1 ,y t-1 ) represents the position coordinates of the movable object at the t-1th moving moment; S4236: Taking the product of the predicted speed of the movable object at the current moment and the moving moment as the moving distance, the predicted position information of the movable object at the current moment is estimated.

7. A method for detecting the travel position of an object in a closed cavity according to claim 6, characterized in that: The method of calculating the correction weight of the predicted position information by using the actual speed and the predicted speed, and then using the correction weight to correct the predicted position information of the movable object at the current moving moment to obtain the final travel position information comprises the following steps: S4241, obtaining the actual speed of the detection node currently passed by calculated by the current contact change time and the previous contact change time, and then obtaining the predicted speed at the moving moment corresponding to the current contact change time calculated by the first exponential smoothing calculation formula, and calculating the angle between the actual speed and the predicted speed; S4242, taking the reciprocal of the angle as a correction weight of the predicted position information; S4243, using the correction weight to correct the predicted position information, to obtain the travel position information of the movable object in the closed cavity at the current moving moment, the correction formula is: In the formula, (x i ,y i ) represents the predicted position information of the movable object in the closed cavity at the i-th moving moment; (x c ,y c ) represents the travel position information of the movable object in the closed cavity; N represents the number of moving moments; w i Represents the correction weight corresponding to the i-th moving moment.

8. A method for detecting the travel position of an object in a closed cavity according to claim 6, characterized in that: The predicted travel position information is verified by using the actual position information corresponding to the next timestamp information to determine whether the travel position of the movable object meets the travel standard. S441, acquiring the contact point change time corresponding to the next timestamp information, at which time the travel position of the movable object is at the detection node corresponding to the contact point change time; S442. Search for the moving moment that is at the same time as the contact change time in the predicted travel position information, and obtain the travel position information predicted by the moving moment, and compare the travel position information with the actual detection node position information. If the difference between the two is less than the standard distance, it is determined that the travel position prediction of the movable object meets the travel standard. If the difference between the two is greater than or equal to the standard distance, it is determined that the travel position prediction of the movable object does not meet the travel standard, and the detection node at this time is used as the initial node to re-predict the position.

9. A system for detecting the travel position of an object in a closed cavity, used to implement the method for detecting the travel position of an object in a closed cavity according to any one of claims 1 to 8, characterized in that: The detection system includes: an equivalent circuit model module, a closed cavity detection module, a wireless communication transmission module and a positioning identification display module, wherein: The equivalent circuit model module is used to install a plurality of evenly distributed magnetic switches as detection nodes on the outer wall of the closed cavity, mark the positions and node numbers, and then construct a control loop and its equivalent circuit model in parallel; The closed cavity detection module is used to calculate the equivalent current signal of the equivalent circuit model in real time by Ohm's law during the detection of the movable object in the closed cavity, and record the contact change of the detection node; The wireless communication transmission module is used to convert the equivalent current signal and contact change information obtained by real-time detection into a signal format, and send them to a signal receiver in the management center by wireless communication; The positioning identification and display module is used to establish a virtual environment of the closed cavity based on the digital twin technology, and then use the motion model of the movable object to locate the position, and import it into the virtual environment for visual display.

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