College multifunctional experiment table and teaching system

Abstract

The invention discloses a multifunctional experiment table for colleges and universities and a teaching system, and belongs to the technical field of laboratory tables. The teaching system comprises a server, at least one experimental terminal and a plurality of leads, the server comprises a database and a data processing module, the experimental terminal is provided with a practical training terminal and a plurality of teaching aids, the practical training terminal is connected with the server through a wireless communication module, and the leads are provided with identification code assemblies used for generating digital signals containing unique identification codes. The data processing module comprises a path analysis assembly and is used for carrying out demodulation and feature extraction on the digital signals to obtain feature vectors and judging whether the digital signals undergo feature changes caused by the teaching aid or not by calculating the similarity of the feature vectors. According to the invention, through accurate identification, positioning and immediate feedback of wiring errors such as excessive traction, less traction and short circuit, equipment damage risks and data errors are reduced, students are guided to autonomously correct errors, and rigorous experimental habits are developed.

Description

Technical Field

[0001] This invention relates to the field of laboratory table technology, specifically to a multifunctional laboratory table and teaching system for colleges and universities. Background Technology

[0002] In electrical and electronic experimental teaching in colleges and universities, a training platform is an experimental table for students to connect circuits, measure data, and analyze experiments. Existing training platforms are usually designed as independent integrated platforms, which integrate a variety of teaching tool modules, such as power supplies, instruments, and loads. Functionally, they can be expanded through built-in or external teaching tools to support students in conducting complex electrical experiments, including data processing that requires drawing charts or pre-calculated formulas. Such training platforms aim to provide a comprehensive experimental environment to help students understand electrical and electronic principles.

[0003] In practice, due to the expansion of school enrollment and limited classroom space, practical training courses often adopt a collaborative model in which multiple students share a single training table. Theoretically, this model can promote student teamwork and simplify the data collection and recording process, with a designated person responsible for recording the data.

[0004] However, existing technologies have revealed problems in actual operation. When multiple students operate at the same time, messy wiring can easily lead to multiple or missing wires or short circuits, affecting experimental data and progress, and causing damage to teaching aids. Teachers, who are monitoring multiple groups, find it difficult to quickly locate the source of the problem, resulting in low teaching efficiency. Summary of the Invention

[0005] The purpose of this invention is to solve the problems in the prior art by proposing a multifunctional experimental table and teaching system for colleges and universities.

[0006] To achieve the above objectives, the present invention adopts the following technical solution: a teaching system, comprising: The server-side component includes a database and a data processing module. At least one experimental terminal, the experimental terminal is equipped with a training end and multiple teaching aids, the training end establishes a data connection with the server through a wireless communication module; Several leads are provided, and an identification code component is provided on the leads. The identification code component establishes a signal transmission connection with the training terminal. The identification code component is configured to generate a digital signal containing a unique identification code; The data processing module includes a path analysis component, which demodulates and extracts features from the digital signals flowing before and after the teaching aid to obtain the feature vector of the signal. By calculating the similarity of feature vectors, it can be determined whether a digital signal has undergone feature changes caused by teaching aids. a) When a digital signal passes through a high-resistance teaching aid, its feature vector has a similarity to the original signal that is lower than the first threshold, and it is determined that the signal features have changed. b) When a digital signal passes through a low-resistance teaching aid, its feature vector has a similarity to the original signal that is higher than the second threshold, and it is determined that the signal features have not changed. c) When the feature vectors of multiple digital signals are detected to be highly similar to the same original signal, it is determined that the digital signals are being transmitted in parallel; The data processing module counts the number of abnormal connections based on the above judgment results.

[0007] The present invention is further configured such that: the identification code component includes a magnetic field detection module and a digital encoder; the magnetic field detection module consists of a magnetic induction coil and a signal conditioning circuit; the magnetic induction coil is coaxially disposed inside the insulation layer of the lead wire; and the signal conditioning circuit includes an instrumentation amplifier, a bandpass filter, and an analog-to-digital converter.

[0008] The present invention is further configured such that: the database includes a connection rule base and an experimental case base; the connection rule base stores offset feature values ​​of different teaching aid offset digital signals; and the experimental case base stores recommended judgment thresholds for different experiments and lead wire connection comparison data.

[0009] The present invention is further configured such that: the data processing module further includes an experimental timing component, which records several timestamps according to the experimental case library based on the time sequence of changes in the lead connection status.

[0010] The present invention is further configured such that the digital signal generated by the digital encoder includes the following data fields: The unique identification code of the lead wire, the signal generation timestamp, the signal strength reference value, and the check code are included. The unique identification code of the lead wire adopts a segmented encoding structure and includes the lead wire type code, the length specification code, and the serial number.

[0011] The present invention is further configured such that: the digital encoder uses direct sequence spread spectrum modulation or orthogonal frequency division multiplexing modulation to modulate the unique identification code onto the carrier to generate the digital signal; the path analysis component tracks the transmission path of the signal by demodulating the digital signal and comparing it with the demodulated identification code.

[0012] The present invention is further configured such that the path analysis component identifies and tracks signal features using the following algorithm: a) Perform time-frequency analysis on the received digital signal and extract feature parameters including signal spectral centroid, spectral roll-off and zero-crossing rate to form a feature vector F; b) Calculate the cosine similarity S between the eigenvector F1 of the signal after passing through the teaching aid and the original eigenvector F0; c) State determination: If S < T1, where T1 is the low similarity threshold, it is determined that the signal has passed through the high-resistance teaching aid and the feature has changed; If S > T2, where T2 is the high similarity threshold and T2 > T1, it is determined that the signal has not passed through the high-resistance teaching aid and the feature has not changed; If the similarity between the eigenvectors of multiple signals is higher than T2, it is determined that these signals originate from the same lead and are parallel transmissions.

[0013] The present invention is further configured such that: the server further includes an early warning synchronization module, which is configured to generate a hierarchical early warning instruction according to the path analysis result and threshold comparison, and synchronize it to the experimental terminal and the server display interface. A multi-color LED indicator array is provided at the top of the experimental terminal, and the multi-color LED indicator array is controlled and connected by the early warning synchronization module.

[0014] A multi-functional experimental table for colleges and universities uses the above teaching system, and wire holes for connecting leads are provided on the teaching aid.

[0015] In summary, the present invention has the following beneficial effects: First: By assigning a digital identity to each lead and analyzing its signal path in real time, the teaching system accurately identifies, locates, and immediately feedbacks the three most typical wiring errors in multi-person collaborative experiments, namely over-wiring, under-wiring, and short-circuiting. This not only greatly reduces the risk of equipment damage and data errors caused by chaotic operations but also guides students to correct errors independently through the immediate feedback mechanism, cultivating students' rigorous experimental habits; Second: At the same time, the system provides a global perspective for teachers, enabling them to be liberated from the cumbersome one-by-one inspections and conduct more targeted teaching guidance, thus significantly improving the safety, efficiency, and teaching quality of experimental teaching. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 is a structural block diagram of the teaching system of the present invention; Figure 2 is a structural schematic diagram of the identification code component and the lead of the present invention; Figure 3 is a structural block diagram of the identification code component of the present invention; Figure 4 is a working flow chart of the data processing module of the present invention; Figure 5 is a structural schematic diagram of the multi-functional experimental table for colleges and universities of the present invention.

[0017] In the figure: 1, teaching aid; 2, lead; 3, identification code component. Detailed Implementation

[0018] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. In the description of the present invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", "top", "bottom", "inner", "outer", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on the present invention. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments.

[0019] A teaching system, such as Figure 1 as well as Figure 2 As shown, the system includes a server, at least one experimental terminal, and several leads 2. The server is located in the teacher's control area, and the experimental terminals are distributed in the student experimental areas. The server includes a database and a data processing module. The database adopts a distributed storage architecture, and the data processing module is implemented using a multi-core processor. The experimental terminals are equipped with training terminals and multiple teaching aids 1. The training terminals establish a data connection with the server through a wireless communication module. The wireless communication module adopts the Wi-Fi 6 protocol. In this embodiment, the teaching aids 1 include an AC voltmeter, an AC ammeter, a power factor meter, a DC voltmeter, a DC milliammeter, an AC current output module, a DC regulated power supply, a constant current source, and a 30W fluorescent tube.

[0020] like Figure 2 as well as Figure 3 As shown, an identification code component 3 is provided on lead 2. The identification code component 3 establishes a signal transmission connection with the training terminal through near-field communication. The identification code component 3 includes a magnetic field detection module and a digital encoder. The magnetic field detection module consists of a magnetic induction coil and a signal conditioning circuit. The magnetic induction coil is coaxially set inside the insulation layer of lead 2, maintaining an insulating distance from the conductor. The signal conditioning circuit includes an instrumentation amplifier, a bandpass filter, and an analog-to-digital converter. The instrumentation amplifier adopts a three-operation amplifier structure, which has a high common-mode rejection ratio and can effectively extract microvolt-level differential signals. Its input terminal is connected to the magnetic induction coil, and the gain is formed by an external resistor. The bandpass filter adopts a fourth-order Butterworth active filter architecture, and the passband frequency range is set according to the carrier frequency of the digital signal. The analog-to-digital converter adopts a 16-bit Σ-Δ ADC, and the sampling rate is set to more than 10 times the carrier frequency. The digital signal generated by the digital encoder contains the following data fields: the unique identity identification code of lead 2, the signal generation timestamp, the signal strength reference value, and the check code. Among them, the unique identity identification code of lead 2 adopts a segmented coding structure, including the lead 2 type code, the length specification code, and the serial number. The digital encoder uses the direct sequence spread spectrum modulation method to modulate the unique identity identification code onto the carrier to generate a digital signal.

[0021] The complete working principle of the identification code component 3: The magnetic field detection module first detects the alternating magnetic field generated by the current in lead 2, converts the magnetic field change into a weak electrical signal through the magnetic induction coil. After this signal is amplified by the instrumentation amplifier of the signal conditioning circuit and the noise is filtered by the band-pass filter, it is converted into a digital signal by the analog-to-digital converter. The digital encoder receives this digital signal as the trigger reference and loads the preset unique identity identification code onto the carrier through the direct sequence spread spectrum modulation method to generate a digital signal containing identity information. In this process, the magnetic field detection module provides the signal detection and initial processing functions, and the digital encoder is responsible for the encoding and modulation of the identity information. The two together form a complete signal generation and identification system.

[0022] As Figure 1 and Figure 4 shown, the data processing module includes a path analysis component, which is implemented by a digital signal processor. The path analysis component demodulates and extracts the features of the digital signals flowing through the teaching aid 1 before and after, and obtains the feature vector of the digital signal. The path analysis component tracks the transmission path of the digital signal by demodulating the digital signal and comparing the demodulated identity identification code. The path analysis component realizes the identification and tracking of signal features through the following algorithm: First, perform time-frequency analysis on the received digital signal, extract feature parameters including the signal spectrum centroid, spectrum roll-off, and zero-crossing rate, and form a feature vector F. Then calculate the cosine similarity S between the feature vector F1 after the digital signal passes through the teaching aid 1 and the original feature vector F0. Finally, perform state determination: If S < T1, where T1 is the low similarity threshold, it is determined that the digital signal passes through the high-resistance teaching aid 1 and the features have changed; If S > T2, where T2 is the high similarity threshold and T2 > T1, it is determined that the digital signal does not pass through the high-resistance teaching aid 1 and the features have not changed; If the similarity between the feature vectors of multiple digital signals is higher than T2, it is determined that these digital signals originate from the same lead 2 and are transmitted in parallel. Based on a large amount of experimental data statistics, the system sets the low similarity threshold T1 = 0.7 and the high similarity threshold T2 = 0.9.

[0023] To ensure the uniqueness of the feature vectors, the teaching system performs the following operations during the initialization phase: First, when each lead 2 leaves the factory, its digital encoder is pre-set with a globally unique identification code, thus ensuring the uniqueness of the encoding at the source of the lead 2. Second, when the system is used for the first time, the server-side data processing module performs reference signal acquisition on each lead 2 individually, extracts its feature vector under a standard test environment, and stores it in the database, establishing a mapping relationship between the identification code and the reference feature vector. Finally, the system periodically performs self-verification of the feature vectors of lead 2. If an abnormally high similarity of the feature vectors of multiple leads is detected, a recalibration process is automatically triggered, maintaining the distinguishability of the feature vectors of each lead 2 by adjusting the signal conditioning circuit parameters or updating the reference feature vector.

[0024] When the digital signal passes through the high-resistance teaching aid 1, the system achieves reliable detection through relevant detection technology. The receiving end uses the same pseudo-random code as the transmitting end to perform correlation operations. Even if the digital signal amplitude is attenuated to the noise level, the effective signal can still be extracted through integral gain. The system also indirectly judges the signal quality by monitoring the demodulation bit error rate of the identification code. When the bit error rate exceeds the threshold, it is determined that the signal characteristics have changed significantly.

[0025] Solution for multiple leads: The teaching system constructs a real-time connection topology diagram of the entire experimental circuit through the path analysis component. When any student connects an extra lead 2, resulting in a redundant connection outside the standard drawing in the topology diagram, the teaching system will trigger a yellow warning on the LED indicator of the experimental terminal through the early warning synchronization module, clearly indicating the wiring redundancy. By pointing out the error in the student's experiment, the student is encouraged to actively think about and modify the lead 2. Solution for missing wiring: The teaching system compares the real-time topology diagram with the standard topology in the database. When the teaching system detects that a certain teaching aid 1 or a certain connection in the standard topology is missing in the real-time topology, it is determined that the wiring is missing. The teaching system will report to the teacher through the server that "the circuit of Experiment Platform N is incomplete, missing the connection between a and b", and give a prompt on the experimental platform to guide students to check and complete the missing wiring. Solution for short circuits: When the teaching system detects that the digital signal has not deviated as expected and directly forms a closed loop, the teaching system will trigger a red alarm through the early warning synchronization module. The LED indicator array on the top of the experimental table will flash red, and a prominent warning will pop up on the server interface and accurately locate the specific lead 2 that forms the short circuit loop. This allows teachers and students to discover and cut off the dangerous connection in a short time, thereby effectively protecting the teaching aid 1 from damage.

[0026] The database includes a connection rule base and an experimental case base. The connection rule base stores the offset feature values ​​of different teaching aid 1 offset digital signals. The experimental case base stores recommended judgment thresholds for different experiments and lead 2 connection comparison data. The data processing module also includes an experimental timing component. The experimental timing component compares the changes in the lead 2 connection status with the experimental case base and records several timestamps, including the experiment start time, the time of each stage, and the end time. The server also includes an early warning synchronization module. The early warning synchronization module is set to generate early warning instructions based on path analysis results and threshold comparisons, and synchronize them to the experimental terminal and the server display interface. The top of the experimental terminal is equipped with a multi-color LED indicator array. The multi-color LED indicator array is controlled and connected by the early warning synchronization module, and displays different color light signals according to different lead 2 wiring conditions.

[0027] like Figure 5 As shown, a multifunctional experimental table for colleges and universities includes the above-mentioned teaching system. The teaching aid 1 is provided with a wire hole for connecting the lead wire 2. The top of the experimental terminal is provided with a multi-color LED indicator array. The teaching aid 1 is connected to the training terminal through a built-in interface, and the lead wire 2 is connected to the teaching aid 1 through the wire hole to realize the circuit connection.

[0028] In practice, teachers first preset the standard wiring topology and judgment thresholds for the experimental project in the database on the server. Taking the experiment "Research on the Relationship between the Light Emitting Power of the Lamp and Circuit Parameters" as an example, the teacher presets the standard topology on the server: AC power supply → power factor meter → AC ammeter → ballast → 30W fluorescent tube → starter → AC power supply circuit, with an AC voltmeter connected in parallel to monitor the power supply voltage. The teacher sets the standard signal characteristic range for each teaching aid 1 in the connection rule base, and sets the characteristic thresholds T1=0.7 and T2=0.9 in the experimental case base. The teacher allows 3 abnormal connections and the standard experimental time is 40 minutes.

[0029] After the students begin the experiment, they connect the circuit according to the standard topology. When lead 2 is connected to the 30W fluorescent tube, the identification code component 3 generates a digital signal containing a unique identification code. The path analysis component analyzes the characteristic changes of the digital signal during transmission in real time. After completing signal feature extraction and preliminary identification, the path analysis component initiates a multi-level database comparison process. First, based on the connection relationship of all digital signals of lead 2, a real-time connection topology graph is dynamically constructed in memory. The system retrieves the standard connection topology graph of the current experimental project from the experimental case library in the database and performs graph isomorphism matching between the real-time topology graph and the standard topology graph.

[0030] When the student correctly connects the ballast, the system detects a significant change in the signal spectrum characteristics, with the cosine similarity S = 0.68 < T1, and this value falls within the range of the standard characteristics of the ballast recorded in the database, determining that the connection is correct. When the student mistakenly connects the AC voltmeter in parallel across the two ends of the starter, this is over-wiring at this time, or when the student forgets to connect the ballast, this is under-wiring at this time, or when one lead wire 2 directly connects the positive and negative poles of the power supply, this is a short circuit at this time. The system will, in the above manner, immediately identify the type of error through real-time topology comparison and signal feature analysis, and trigger warnings at corresponding levels to guide the student to correct in a timely manner.

[0031] During the experiment, the student changes the circuit parameters by adjusting the AC current output module, observes the change in the light emission degree of the lamp tube, and at the same time uses an AC voltmeter, an AC ammeter, and a power factor meter to record relevant data. The experimental timing component records the time consumed in each measurement stage. The system compares the measured data with the theoretical values in real time, monitors the working state of the circuit, and when it detects that the power factor is lower than 0.5, the system automatically prompts the student to check the connection of the compensation capacitor.

[0032] After the experiment, the system generates a detailed report, including key indicators such as the total experimental time, the number of abnormal connections, the integrity of data records, and the measurement accuracy of the power factor. Through this system, the teacher can grasp the progress of each experimental bench in real time, and conduct centralized guidance on common connection problems, such as incorrect connection order between the ballast and the lamp tube, improper parallel connection position of the voltmeter, etc.

[0033] Beneficial effects: First: By assigning a digital identity to each lead wire 2 and analyzing its signal path in real time, the teaching system accurately identifies, locates, and immediately feedbacks the three most typical wiring errors in multi-person collaborative experiments, namely over-wiring, under-wiring, and short circuit. This not only greatly reduces the risk of equipment damage and data errors caused by chaotic operations, but also guides students to correct errors independently through the immediate feedback mechanism, cultivating students' rigorous experimental habits. Second: At the same time, the system provides a global perspective for the teacher, enabling the teacher to be liberated from the cumbersome process of checking one by one and conduct more targeted teaching guidance, thus significantly improving the safety, efficiency, and teaching quality of experimental teaching.

[0034] For those skilled in the art, it is obvious that the present invention is not limited to the details of the above exemplary embodiments, and can be implemented in other specific forms without departing from the spirit or basic characteristics of the present invention. Therefore, from any point of view, the embodiments should be regarded as exemplary and non-restrictive. The scope of the present invention is defined by the appended claims rather than the above description. Therefore, it is intended to embrace all changes falling within the meaning and scope of the equivalent elements of the claims in the present invention. Any reference signs in the claims should not be regarded as limiting the claims involved.

[0035] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A teaching system, characterized in that: Including: A server, which includes a database and a data processing module; At least one experimental terminal, which is provided with a training end and a plurality of teaching aids, and the training end establishes a data connection with the server through a wireless communication module; A number of leads, on which an identification code component is provided, and the identification code component establishes a signal transmission connection with the training end; The identification code component is set to generate a digital signal containing a unique identity identification code; The data processing module includes a path analysis component, which demodulates and extracts features from the digital signals before and after passing through the teaching aids to obtain the feature vectors of the signals; By calculating the similarity of the feature vectors, it is determined whether the digital signal has undergone a feature change caused by the teaching aid; a) When the digital signal passes through a high-resistance teaching aid, The similarity of its feature vector compared with the original signal is lower than the first threshold, and it is determined that the signal feature has changed; b) When the digital signal passes through a low-resistance teaching aid, The similarity of its feature vector compared with the original signal is higher than the second threshold, and it is determined that the signal feature has not changed; c) When it is detected that the feature vectors of multiple digital signals are highly similar to the same original signal, it is determined that the digital signals are transmitted in parallel; The data processing module statistically counts the number of abnormal connections based on the above determination results.

2. The teaching system according to claim 1, characterized in that: The identification code component includes a magnetic field detection module and a digital encoder. The magnetic field detection module consists of a magnetic induction coil and a signal conditioning circuit. The magnetic induction coil is coaxially arranged inside the insulating layer of the lead. The signal conditioning circuit includes an instrumentation amplifier, a band-pass filter, and an analog-to-digital converter.

3. The teaching system according to claim 2, characterized in that: The database includes a connection rule library and an experimental case library. The connection rule library stores the offset feature values of different teaching aids for offsetting digital signals. The experimental case library stores the recommended judgment thresholds for different experiments and the lead connection comparison data.

4. The teaching system according to claim 3, characterized in that: The data processing module further includes an experiment timing component, which records a number of timestamps by comparing the experiment case library according to the change timing of the lead connection state.

5. A teaching system according to claim 4, characterized in that: The digital signal generated by the digital encoder includes the following data fields: The unique identity identification code of the lead, the signal generation timestamp, the signal intensity reference value, and the check code. The unique identity identification code of the lead adopts a segmented coding structure, and the unique identity identification code of the lead includes a lead type code, a length specification code, and a serial number.

6. The teaching system according to claim 1, characterized in that: The digital encoder modulates the unique identity identification code onto the carrier by using direct sequence spread spectrum modulation or orthogonal frequency division multiplexing modulation to generate the digital signal. The path analysis component tracks the signal transmission path by demodulating the digital signal and comparing the demodulated identity identification code.

7. The teaching system according to claim 1, characterized in that: The path analysis component realizes the identification and tracking of signal features through the following algorithm: a) Perform time-frequency analysis on the received digital signal, extract feature parameters including the signal spectrum centroid, spectrum roll-off, and zero-crossing rate, and form a feature vector F; b) Calculate the cosine similarity S between the feature vector F1 of the signal after passing through the teaching aid and the original feature vector F0; c) State determination: If S < T1, where T1 is the low similarity threshold, it is determined that the signal has passed through a high-resistance teaching aid and the feature has changed; If S>T2, T2 is the high similarity threshold, and T2>T1, then it is determined that the signal did not pass through the high-resistance teaching aid and the features did not change. If the similarity between the feature vectors of multiple signals is higher than T2, then these signals are determined to originate from the same lead and are transmitted in parallel.

8. A teaching system according to claim 1, characterized in that: The server also includes an early warning synchronization module, which is configured to generate tiered early warning instructions based on path analysis results and threshold comparisons, and synchronize them to the experimental terminal and the server display interface. The experimental terminal is equipped with a multi-color LED indicator array on its top, which is controlled and connected by the early warning synchronization module.

9. A multifunctional experimental table for colleges and universities, characterized in that: Using the teaching system as described in any one of claims 1 to 8, the teaching aid is provided with a wire hole for connecting a lead wire.

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