Signal acquisition circuit and maglev train

Abstract

The utility model discloses a signal acquisition circuit and a magnetically levitated train, relates to the field of signal processing, and can prevent a gap signal from generating a negative voltage signal due to sensor output characteristic offset or circuit design defects by superposing a forward direct current bias voltage, thereby ensuring the stability and reliability of the signal. The intensity of the gap signal can be further enhanced through the signal amplification link, so that the gap signal can more accurately reflect the gap information between the train and the track in the subsequent sampling process, and the signal acquisition precision is improved; the signal sampling circuit is used for sampling the adjusting signal, noise interference can be filtered out more effectively, and the quality of the gap signal is further improved. Therefore, the utility model can solve the problems of insufficient precision of gap signals, obvious noise interference, possible generation of negative voltage signals and the like, and provides more reliable signal acquisition guarantee for safe and stable operation of the magnetically levitated train.

Description

Technical Field

[0001] This utility model relates to the field of signal processing, and in particular to a signal acquisition circuit and a magnetic levitation train. Background Technology

[0002] Maglev trains use levitation sensors and guidance sensors to monitor the gap between the train and the track. These sensors collect gap signals in real time and feed them back to the control system, enabling levitation and guidance control of the train. High-precision acquisition of the gap signals is crucial for ensuring the safe and stable operation of the train.

[0003] However, current technologies suffer from problems such as insufficient accuracy and significant noise interference in the gap signals acquired by sensors. Furthermore, conventional gap signal acquisition circuits may generate negative voltage signals due to electromagnetic interference, sensor output characteristic deviations, or circuit design defects, leading to abnormal gap acquisition by the sensor and consequently causing abnormal control commands, which threatens the safety of train operation. Utility Model Content

[0004] The purpose of this invention is to provide a signal acquisition circuit and a maglev train, which solves problems such as insufficient accuracy of gap signals, significant noise interference, and the potential generation of negative voltage signals, thereby providing a more reliable signal acquisition guarantee for the safe and stable operation of maglev trains.

[0005] To solve the above-mentioned technical problems, this utility model provides a signal acquisition circuit, comprising:

[0006] The signal adjustment circuit has its input terminal connected to the output terminal of the gap sensor. It is configured to superimpose a preset positive DC bias voltage on the gap signal output by the gap sensor and amplify the superimposed signal to obtain the adjustment signal.

[0007] A signal sampling circuit, the input of which is connected to the output of the signal adjustment circuit, is configured to sample the adjustment signal to obtain an intermittent sampling signal.

[0008] Optionally, the signal conditioning circuit includes:

[0009] A voltage output circuit configured to output the preset positive DC bias voltage;

[0010] The signal amplification circuit has its input terminals connected to the output terminals of the gap sensor and the voltage output circuit, respectively. It is configured to superimpose the preset positive DC bias voltage onto the gap signal and amplify the superimposed signal to obtain the adjustment signal.

[0011] Optionally, the signal amplification circuit includes:

[0012] Inverting amplifier, first resistor, second resistor, third resistor, and fourth resistor;

[0013] The inverting input terminal of the inverting amplifier is connected to the first terminal of the first resistor, the first terminal of the second resistor, and the first terminal of the third resistor, respectively. The non-inverting input terminal of the inverting amplifier is grounded through the fourth resistor. The output terminal of the inverting amplifier is connected to the second terminal of the second resistor and the input terminal of the signal sampling circuit, respectively. The second terminal of the first resistor is connected to the output terminal of the gap sensor, and the second terminal of the third resistor is connected to the output terminal of the voltage output circuit.

[0014] Optionally, when the signal sampling circuit is an analog-to-digital converter IC3, the voltage output circuit reuses the sub-circuit in the analog-to-digital converter IC3 used for outputting voltage, and the reference circuit output terminal of the signal sampling circuit is connected to the input terminal of the signal amplification circuit as the output terminal of the voltage output circuit.

[0015] Optionally, it also includes:

[0016] The signal preprocessing circuit has its input terminal connected to the output terminal of the gap sensor and its output terminal connected to the signal adjustment circuit. It is configured to filter out interference signals in the gap signal and transmit the processed signal to the signal adjustment circuit.

[0017] Optionally, the signal preprocessing circuit includes at least: a fifth resistor and a first capacitor;

[0018] The first end of the fifth resistor is connected to the output end of the gap sensor, the second end of the fifth resistor is connected to the output end of the signal adjustment circuit and the first end of the first capacitor, and the second end of the first capacitor is grounded.

[0019] Optionally, it also includes:

[0020] A voltage protection circuit, whose input terminal is connected to the output terminal of the signal amplification circuit and whose output terminal is connected to the input terminal of the signal sampling circuit, is configured to turn on when the voltage of the adjustment signal is greater than a preset threshold, so as to reduce the adjustment signal to a preset clamping voltage and output it to the signal sampling circuit.

[0021] Optionally, the voltage protection circuit includes:

[0022] At least two clamping diodes are provided. The anode of the first clamping diode is connected to the output terminal of the signal amplification circuit, the cathode of the first clamping diode is connected to the anode of the second clamping diode, and the cathode of the second clamping diode is connected to the input terminal of the signal sampling circuit.

[0023] Optionally, the voltage protection circuit further includes:

[0024] At least one sixth resistor is disposed between the cathode of the second clamping diode and the input terminal of the signal sampling circuit.

[0025] To solve the above-mentioned technical problems, this utility model provides a magnetic levitation train, including a gap sensor and the signal acquisition circuit described above.

[0026] This invention provides a signal acquisition circuit and a maglev train, relating to the field of signal processing. By superimposing a positive DC bias voltage, it avoids negative voltage signals in the gap signal caused by sensor output characteristic deviations or circuit design defects, ensuring signal stability and reliability. The signal amplification stage further enhances the strength of the gap signal, enabling it to more accurately reflect the gap information between the train and the track during subsequent sampling, improving signal acquisition accuracy. Sampling the adjustment signal through a signal sampling circuit effectively filters out noise interference, further improving the quality of the gap signal. Therefore, this invention solves problems such as insufficient gap signal accuracy, significant noise interference, and the potential for negative voltage signals, providing a more reliable signal acquisition guarantee for the safe and stable operation of maglev trains. Attached Figure Description

[0027] To more clearly illustrate the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this utility model. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0028] Figure 1 A block diagram of a signal acquisition circuit provided by this utility model;

[0029] Figure 2 The present invention provides a circuit diagram of a signal acquisition circuit. Detailed Implementation

[0030] The core of this invention is to provide a signal acquisition circuit and a maglev train, which solves problems such as insufficient accuracy of gap signals, significant noise interference, and the potential generation of negative voltage signals, thus providing a more reliable signal acquisition guarantee for the safe and stable operation of maglev trains.

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0032] like Figure 1 This utility model provides a signal acquisition circuit, including: a signal adjustment circuit 12, whose input terminal is connected to the output terminal of a gap sensor, configured to superimpose a preset positive DC bias voltage on the gap signal output by the gap sensor, and amplify the superimposed signal to obtain an adjustment signal; and a signal sampling circuit 13, whose input terminal is connected to the output terminal of the signal adjustment circuit 12, configured to sample the adjustment signal to obtain a gap sampling signal.

[0033] In this embodiment, the signal sampling circuit 13 is designed to process and optimize the gap signal output by the gap sensor in order to improve the quality and reliability of the signal, thereby meeting the requirements of maglev trains for high-precision acquisition of gap signals.

[0034] First, the gap sensor's function is to monitor the gap between the train and the track in real time and convert this physical quantity into an electrical signal output. However, the gap signal directly output from the sensor often has some problems, such as weak signal strength, potential noise interference, or the generation of negative voltage signals in certain situations. These problems can affect the accuracy and reliability of the signal. To overcome these shortcomings, the signal conditioning circuit 12 preprocesses the gap signal.

[0035] The core function of the signal conditioning circuit 12 is to superimpose the gap signal with a preset positive DC bias voltage. This preset positive DC bias voltage effectively prevents the gap signal from exhibiting negative voltage during subsequent processing. Negative voltage signals can lead to signal processing abnormalities in some circuit designs, and may even be misjudged as fault signals, thus affecting the normal operation of the train. By superimposing the preset positive DC bias voltage, the signal baseline can be raised, ensuring that the signal remains within the positive voltage range, thereby improving signal stability and reliability.

[0036] After applying the bias voltage, the signal conditioning circuit 12 further amplifies the signal. The amplification stage enhances the signal amplitude, making it more suitable for subsequent sampling and processing. Signal amplification not only improves the signal-to-noise ratio and reduces the impact of noise, but also makes the signal more stable during transmission, preventing misjudgment or loss due to weak signals. The amplified signal, called the adjusted signal, has undergone preliminary optimization and possesses better quality and stability.

[0037] The adjustment signal is then transmitted to the input of the signal sampling circuit 13. The main function of the signal sampling circuit 13 is to sample the adjustment signal, that is, to convert the continuous analog signal into a discrete digital signal so that the subsequent control system can process and analyze it. The sampling process is a key step in signal acquisition, as it determines the accuracy and real-time performance of the signal acquisition. By sampling the adjustment signal, a gap sampling signal can be obtained. This signal can accurately reflect the gap information between the train and the track, providing reliable data support for the train's suspension and guidance control system.

[0038] In summary, this signal sampling circuit 13 optimizes the gap signal through the signal adjustment circuit 12, including superimposing a positive DC bias voltage and signal amplification, effectively solving the problems of negative voltage and insufficient signal strength that may exist in the gap signal. The optimized and adjusted signal is then sampled by the signal sampling circuit 13, ultimately obtaining a high-precision and high-reliability gap sampling signal, thus providing important technical support for the safe and stable operation of maglev trains.

[0039] In one exemplary embodiment, the signal adjustment circuit 12 includes: a voltage output circuit configured to output a preset positive DC bias voltage; and a signal amplification circuit, the input terminals of which are respectively connected to the output terminals of the gap sensor and the voltage output circuit, configured to superimpose the preset positive DC bias voltage onto the gap signal and amplify the superimposed signal to obtain an adjustment signal.

[0040] In this embodiment, the core function of the voltage output circuit is to output a preset positive DC bias voltage. This preset positive DC bias voltage is a stable DC level, and its value is preset based on the output characteristics of the gap sensor and the requirements of subsequent circuits. The introduction of the preset positive DC bias voltage is mainly to solve the problem of negative voltage that may occur in the gap signal under certain circumstances. By superimposing a positive DC bias voltage, the baseline of the gap signal can be raised to a safe positive voltage range, ensuring that the signal remains stable throughout the entire processing and that negative voltage does not occur.

[0041] Through this design, the signal adjustment circuit 12 can effectively solve the problems of negative voltage and insufficient signal strength that may be encountered during the acquisition of gap signals. The superposition of the preset positive DC bias voltage ensures the stability of the signal, while the signal amplification circuit further enhances the amplitude and quality of the signal. The final adjusted signal is a high-quality signal that has been optimized, providing a more accurate and reliable input for the subsequent signal sampling circuit 13, thus providing important technical support for the levitation and guidance control of the maglev train.

[0042] like Figure 2 In one exemplary embodiment, the signal amplification circuit includes: an inverting amplifier IC2, a first resistor R1, a second resistor R2, a third resistor R3, and a fourth resistor R4; the inverting input terminal of the inverting amplifier IC2 is connected to the first terminal of the first resistor R1, the first terminal of the second resistor R2, and the first terminal of the third resistor R3, respectively; the non-inverting input terminal of the inverting amplifier IC2 is grounded through the fourth resistor R4; the output terminal of the inverting amplifier IC2 is connected to the second terminal of the second resistor R2 and the input terminal of the signal sampling circuit 13, respectively; the second terminal of the first resistor R1 is connected to the output terminal of the gap sensor; and the second terminal of the third resistor R3 is connected to the output terminal of the voltage output circuit.

[0043] In this embodiment, the signal amplification circuit is designed based on the synergistic effect of the inverting amplifier IC2 and its peripheral resistor network. Through precise circuit connection and resistor configuration, the superposition and amplification of the gap signal and the preset positive DC bias voltage are realized, thereby providing a high-quality adjustment signal for subsequent signal acquisition.

[0044] The inverting amplifier IC2 features high input impedance, low output impedance, and high gain. The inverting input of IC2 is a crucial node in signal processing; it is connected to multiple resistors to achieve signal superposition and feedback control. Specifically, the inverting input of IC2 is connected to one end of the first resistor R1, the second resistor R2, and the third resistor R3, respectively. This connection allows IC2 to receive signals from two different paths: the gap signal output from the gap sensor and the preset positive DC bias voltage provided by the voltage output circuit.

[0045] The other end of the first resistor R1 is connected to the output of the gap sensor, which is responsible for introducing the raw gap signal output by the gap sensor into the inverting input of the inverting amplifier IC2. The gap signal is usually a weak analog signal, and its amplitude and stability may be affected by various factors, such as the accuracy of the sensor and environmental noise. Through the first resistor R1, the gap signal is introduced into the inverting amplifier IC2, preparing it for subsequent processing.

[0046] The other end of the third resistor R3 is connected to the output terminal of the voltage output circuit, responsible for introducing the preset positive DC bias voltage into the inverting input terminal of the inverting amplifier IC2. The function of the positive DC bias voltage is to raise the baseline of the gap signal to a safe positive voltage range, thereby avoiding the occurrence of negative voltage in the signal during subsequent processing.

[0047] The non-inverting input of inverting amplifier IC2 is grounded through the fourth resistor R4. This grounding configuration provides a stable reference level for inverting amplifier IC2, ensuring that the amplifier's output signal can be amplified at a fixed reference level. The choice of grounding resistor also has a certain impact on the amplifier's performance and stability; it can help suppress common-mode noise and improve signal quality.

[0048] The output of inverting amplifier IC2 is connected to the other end of the second resistor R2 and to the input of signal sampling circuit 13. The second resistor R2 acts as a feedback resistor, and together with the first resistor R1, it determines the gain of inverting amplifier IC2. The gain of inverting amplifier IC2 is -R2 / R3, and the output voltage U0 of inverting amplifier IC2 is -Ui × R2 × R1 (if a fifth resistor R5 is connected at the front end, the output voltage U0 of inverting amplifier IC2 is -Ui × R2 × (R1 + R5), where Ui is the input signal (gap signal) at the inverting input terminal of inverting amplifier IC2). This feedback mechanism allows the amplifier to precisely control the signal amplification factor, ensuring that the amplitude of the output signal meets the requirements of the subsequent signal sampling circuit 13.

[0049] When the gap signal and bias voltage are introduced into the inverting input of the inverting amplifier IC2 through the first resistor R1 and the third resistor R3, they are superimposed at this node. The inverting amplifier IC2 amplifies the superimposed signal according to the ratio of resistors R2 and R6. The amplified signal is output from the output of the inverting amplifier IC2 and fed back to the inverting input through the second resistor R2 to achieve a stable amplification effect. Finally, the amplified signal is transmitted to the input of the signal sampling circuit 13 as an adjustment signal for subsequent processing.

[0050] Through this design, the signal amplification circuit not only superimposes the gap signal with the preset positive DC bias voltage, but also enhances the signal amplitude and stability through the amplification effect of the inverting amplifier IC2. This circuit structure effectively solves the problems of negative voltage and insufficient signal strength that may be encountered during the acquisition of the gap signal. Simultaneously, through precise resistor configuration and feedback mechanisms, it ensures high-precision signal processing. The resulting adjustment signal is a high-quality, optimized signal that provides reliable data support for the levitation and guidance control of the maglev train.

[0051] In one exemplary embodiment, when the signal sampling circuit 13 is an analog-to-digital converter IC3, the voltage output circuit reuses the sub-circuit in the analog-to-digital converter IC3 used for output voltage, and the reference circuit output terminal of the signal sampling circuit 13 is connected to the input terminal of the signal amplification circuit as the output terminal of the voltage output circuit.

[0052] In this embodiment, when the signal sampling circuit 13 uses an analog-to-digital converter IC3 (ADC), the voltage output circuit and the reference circuit of the analog-to-digital converter IC3 are reused. This design not only simplifies the circuit structure, but also improves the system integration and reliability.

[0053] Specifically, the analog-to-digital converter IC3 typically includes a reference circuit, whose main function is to provide a stable reference voltage for the ADC, enabling accurate conversion of analog signals into digital signals. In this embodiment, the output of the ADC's reference circuit is not only used for the ADC's own reference voltage requirement but is also multiplexed as the output of the voltage output circuit. This means that the stable reference voltage output by the reference circuit can simultaneously serve as a preset positive DC bias voltage, directly provided to the input of the signal amplification circuit.

[0054] The advantage of this multiplexing design is that it avoids the need for an additional independent voltage output circuit to generate the bias voltage, thereby reducing the number and complexity of circuit components. Simultaneously, since the reference circuit of the analog-to-digital converter IC3 typically possesses high precision and stability, using the voltage output from this circuit as the bias voltage ensures that the DC bias voltage superimposed in the signal amplification circuit exhibits the same high precision and stability. This not only optimizes signal quality but also improves the performance of the entire signal sampling circuit 13.

[0055] Furthermore, connecting the ADC's reference circuit output to the signal amplification circuit input allows the bias voltage to directly participate in the signal amplification process. In the signal amplification circuit, the gap signal output from the gap sensor is superimposed on this bias voltage and amplified, thus avoiding negative voltage and enhancing signal amplitude and stability. Finally, the optimized signal is sent to the analog-to-digital converter IC3 for sampling and digitization, providing a high-precision gap sampling signal for the subsequent control system.

[0056] Through this multiplexing design, the signal sampling circuit 13 not only achieves functional optimization, but also improves the overall performance and reliability of the system, while reducing cost and circuit complexity.

[0057] In one exemplary embodiment, the system further includes a signal preprocessing circuit 11, whose input terminal is connected to the output terminal of the gap sensor and whose output terminal is connected to the signal adjustment circuit 12. This circuit is configured to filter out interference signals in the gap signal and transmit the processed signal to the signal adjustment circuit. In one exemplary embodiment, the signal preprocessing circuit 11 includes at least a fifth resistor R5 and a first capacitor C1. The first end of the fifth resistor R5 is connected to the output terminal of the gap sensor, and the second end of the fifth resistor R5 is connected to both the output terminal of the signal adjustment circuit and the first end of the first capacitor C1. The second end of the first capacitor C1 is grounded.

[0058] In this embodiment, the signal preprocessing circuit 11 is introduced at the front end of the signal sampling circuit 13. Its main function is to perform preliminary processing on the raw signal output by the gap sensor to filter out interference signals, thereby improving the signal quality and stability. The design of this preprocessing circuit is based on a simple passive filtering principle, and may include, but is not limited to, the fifth resistor R5 and the first capacitor C1.

[0059] Specifically, the fifth resistor, R5, is responsible for receiving the original gap signal. The resistor acts as a damper and also helps match the impedance of the circuit, ensuring the signal can be smoothly transmitted to subsequent circuits. This combination of resistor and capacitor forms a low-pass filter (RC filter). The principle of a low-pass filter is to utilize the characteristic that a capacitor has lower impedance to high-frequency signals and higher impedance to low-frequency signals, thereby filtering out high-frequency interference signals. In practical applications, the signal output by the gap sensor may contain various noises and interferences, such as high-frequency electromagnetic interference and power supply ripple. These high-frequency interference signals may affect subsequent signal processing circuits, reducing signal accuracy and reliability. Through the action of the RC filter, high-frequency interference signals are effectively filtered out, while the low-frequency gap signal is preserved.

[0060] The pre-processed signal, i.e., the signal after interference has been filtered out, is transmitted to the input terminal of the signal adjustment circuit 12 through the connection point of the fifth resistor R5 and the first capacitor C1. This pre-processing not only improves the signal quality but also provides a more stable input signal for subsequent signal adjustment and amplification circuits, thereby further enhancing the performance of the entire signal sampling circuit 13.

[0061] Through this design, the signal preprocessing circuit 11 effectively filters the gap signal using a simple combination of resistors and capacitors, providing a cleaner signal foundation for subsequent signal processing. This low-cost and efficient preprocessing method has significant application value in the signal sampling circuit 13, and can significantly improve the system's anti-interference capability and the accuracy of signal acquisition.

[0062] In one exemplary embodiment, the circuit further includes a voltage protection circuit, the input of which is connected to the output of the signal amplification circuit and the output of which is connected to the input of the signal sampling circuit 13. The circuit is configured to turn on when the voltage of the adjustment signal is greater than a preset threshold, so as to reduce the preset clamping voltage of the adjustment signal and output it to the signal sampling circuit 13.

[0063] In this embodiment, a voltage protection circuit is introduced to enhance the stability and reliability of the entire system. The function of the voltage protection circuit is to monitor and limit the voltage amplitude of the adjustment signal during signal processing, ensuring that the signal is transmitted within a safe voltage range and preventing damage or misjudgment of the subsequent signal sampling circuit 13 due to excessively high voltage.

[0064] Specifically, the input terminal of the voltage protection circuit is connected to the output terminal of the signal amplification circuit to receive the amplified adjustment signal. When the voltage amplitude of the adjustment signal exceeds a preset threshold, the voltage protection circuit is triggered and turned on. This threshold is usually preset based on the input voltage range of the signal sampling circuit 13 and the system's safety requirements to ensure that the signal does not exceed the circuit's tolerance during subsequent processing. Once the voltage of the adjustment signal exceeds the preset threshold, the voltage protection circuit will reduce the signal voltage to a preset clamping voltage to achieve a safe voltage level. The preset threshold is a fixed voltage value set in the voltage protection circuit. When the input signal exceeds this value, the circuit will reduce the signal to the preset clamping voltage, thereby preventing the signal amplitude input to the signal sampling circuit 13 from being too high. This not only protects the signal sampling circuit 13 from excessive voltage impact but also ensures the integrity and accuracy of the signal, enabling the signal sampling circuit 13 to operate stably without being affected even when the signal amplitude is abnormal.

[0065] When a seventh resistor R7 is provided between the output of the original signal amplification circuit and the input of the signal sampling circuit 13, the voltage protection circuit is connected in parallel with the seventh resistor R7.

[0066] By introducing a voltage protection circuit, the signal sampling circuit 13 exhibits enhanced robustness when processing intermittent signals. It not only effectively handles fluctuations in signal amplitude but also maintains stable system operation in complex electromagnetic environments. This design is particularly important in applications such as maglev trains, where signal acquisition accuracy and reliability are extremely critical, effectively ensuring the safe operation of the train.

[0067] In one exemplary embodiment, the voltage protection circuit includes at least two clamping diodes, the anode of the first clamping diode D20 is connected to the output terminal of the signal amplification circuit, the cathode of the first clamping diode D20 is connected to the anode of the second clamping diode D21, and the cathode of the second clamping diode D21 is connected to the input terminal of the signal sampling circuit 13.

[0068] In this embodiment, the voltage protection circuit uses at least two clamping diodes to effectively clamp and protect the adjustment signal voltage, ensuring that the signal is transmitted within a safe voltage range, while preventing excessive voltage from damaging the subsequent signal sampling circuit 13.

[0069] Specifically, by connecting two clamping diodes in series, when the voltage of the adjustment signal exceeds a preset threshold, the two clamping diodes conduct, clamping the voltage of the adjustment signal within a preset safe range. This clamping mechanism not only improves the reliability of voltage protection but also effectively prevents instantaneous voltage spikes from damaging subsequent circuits.

[0070] When the voltage of the adjustment signal is within the normal range, the clamping diode will not conduct, and the signal can be transmitted normally to the signal sampling circuit 13 (as described by R7 in the above embodiment). Only when the voltage of the adjustment signal exceeds a preset threshold will the clamping diode activate its protection function, reducing the signal voltage to a safe level. This design ensures the integrity and accuracy of the signal under normal operating conditions while providing an effective protection mechanism in abnormal situations.

[0071] Specifically, clamping diodes D1 and D2 form a series clamping circuit to clamp the input signal voltage within a safe range. When the input signal voltage exceeds a preset threshold, the clamping diodes activate their protection function. Assuming the ADC chip's internal reference voltage (i.e., the preset forward DC bias voltage) is 2.5V, and the forward voltage drop of each diode is approximately 0.7V, then the total voltage drop across the two diodes is 1.4V. In this case, if the input signal voltage exceeds 2.5V - 1.4V = 1.1V, clamping diodes D1 and D2 will conduct, reducing the excess voltage across the diodes and thus clamping the output signal voltage above 1.1V.

[0072] With this voltage protection circuit composed of clamping diodes, the signal sampling circuit 13 can operate stably in complex electromagnetic environments, while avoiding circuit damage or data acquisition errors caused by excessively high signal amplitude. This design is particularly important in high-precision signal processing systems, significantly improving system reliability and security.

[0073] In one exemplary embodiment, the voltage protection circuit further includes at least one sixth resistor R6 disposed between the cathode of the second clamping diode D21 and the input terminal of the signal sampling circuit 13.

[0074] In this embodiment, the voltage protection circuit includes not only two clamping diodes, but also at least one sixth resistor R6 to further optimize the circuit's performance and protection function.

[0075] The introduction of the sixth resistor, R6, further optimizes the performance of the clamping circuit. The main function of R6 is to limit the current through the clamping diode, preventing damage to the diode or subsequent circuitry due to excessive current. Simultaneously, the presence of R6 also generates a small voltage drop, further reducing the voltage of the signal input to the signal sampling circuit 13. By appropriately selecting the value of R6, the relationship between current limiting and voltage drop can be balanced, ensuring stable operation of the circuit even when the protection function is activated.

[0076] By using a simple combination of clamping diodes and resistors, precise clamping of the input signal is achieved, while providing effective overvoltage protection. This not only prevents damage to the ADC chip from excessively high signal voltage but also ensures signal transmission within a safe range, thereby improving the reliability and stability of the entire signal acquisition system.

[0077] In one specific embodiment, the first end of the fifth resistor R5 is connected to the output terminal of the gap sensor, the second end of the fifth resistor R5 is connected to the first end of the first capacitor C1 and the second end of the first resistor R1, the second end of the first capacitor C1 is connected to the second end of the fourth resistor R4 and ground, the first end of the fourth resistor R4 is connected to the non-inverting input terminal of the inverting amplifier IC2, the second end of the first resistor R1 is connected to the inverting input terminal of the inverting amplifier IC2, the first end of the second resistor R2 and the first end of the third resistor R3, the second end of the second resistor R2 is connected to the output terminal of the inverting amplifier IC2 and the first end of the seventh resistor R7, the second end of the seventh resistor R7 is connected to the VIN pin of the signal sampling circuit 13, the second end of the third resistor R3 is connected to the CAP pin of the signal sampling circuit 13 and the anode of the first clamping diode D20, the cathode of the first clamping diode D20 is connected to the anode of the second clamping diode D21, the cathode of the second clamping diode D21 is connected to the first end of the sixth resistor R6, and the second end of the sixth resistor R6 is connected to the second end of the seventh resistor R7 and the VIN pin of the signal sampling circuit 13.

[0078] The specific workflow is as follows: R5 and C1 filter the gap signal, IC2 amplifies its own input signal in reverse and superimposes the preset positive DC bias voltage output by CAP. When the signal output by IC2 is greater than the voltage division value of D20-D21-R6, the output signal of IC2 passes through R2, R3, D20, D21, R6 and then to VIN of IC3. When the signal output by IC2 is not greater than the voltage division value of D20-D21-R6, the output signal of IC2 reaches VIN of IC3 through R7.

[0079] To solve the above-mentioned technical problems, this utility model provides a magnetic levitation train, including a gap sensor and the aforementioned signal acquisition circuit.

[0080] To address the issues of insufficient accuracy, significant noise interference, and potential negative voltage signals in the gap signal acquisition process of maglev trains, this invention also provides a maglev train, including a gap sensor and the aforementioned optimized signal acquisition circuit.

[0081] Gap sensors are used to monitor the gap between the train and the track in real time and convert this physical quantity into an electrical signal output (i.e., a gap signal). However, the signal output directly from the sensor often suffers from problems such as noise interference, insufficient signal strength, or the possibility of negative voltage. These problems may affect the normal operation of the train's suspension and guidance control system, and even threaten the safety of the train.

[0082] To address these issues, this invention introduces an improved signal acquisition circuit. This circuit optimizes the gap signal through a signal adjustment circuit, including superimposing a preset positive DC bias voltage to prevent negative voltage, and enhancing the signal amplitude and stability through a signal amplification circuit.

[0083] Through this design, the magnetic levitation train system of this invention can achieve high-precision and high-stability gap signal acquisition, effectively filter out noise interference, avoid the occurrence of negative voltage signals, and maintain reliable operation of the system in complex electromagnetic environments. Ultimately, the optimized signal acquisition circuit provides high-quality gap sampling signals for the train's levitation and guidance control system, thereby ensuring the safe and stable operation of the magnetic levitation train.

[0084] For other descriptions of the maglev train, please refer to the above embodiments; these will not be repeated here.

[0085] It should also be noted that, in this specification, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0086] The above description of the disclosed embodiments enables those skilled in the art to make or use the present invention. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the general principles defined herein may be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention is not to be limited to the embodiments shown herein, but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A signal acquisition circuit, characterized in that, include: The signal adjustment circuit has its input terminal connected to the output terminal of the gap sensor. It is configured to superimpose a preset positive DC bias voltage on the gap signal output by the gap sensor and amplify the superimposed signal to obtain the adjustment signal. A signal sampling circuit, the input of which is connected to the output of the signal adjustment circuit, is configured to sample the adjustment signal to obtain an intermittent sampling signal.

2. The signal acquisition circuit as described in claim 1, characterized in that, The signal conditioning circuit includes: A voltage output circuit configured to output the preset positive DC bias voltage; The signal amplification circuit has its input terminals connected to the output terminals of the gap sensor and the voltage output circuit, respectively. It is configured to superimpose the preset positive DC bias voltage onto the gap signal and amplify the superimposed signal to obtain the adjustment signal.

3. The signal acquisition circuit as described in claim 2, characterized in that, The signal amplification circuit includes: Inverting amplifier, first resistor, second resistor, third resistor, and fourth resistor; The inverting input terminal of the inverting amplifier is connected to the first terminal of the first resistor, the first terminal of the second resistor, and the first terminal of the third resistor, respectively. The non-inverting input terminal of the inverting amplifier is grounded through the fourth resistor. The output terminal of the inverting amplifier is connected to the second terminal of the second resistor and the input terminal of the signal sampling circuit, respectively. The second terminal of the first resistor is connected to the output terminal of the gap sensor, and the second terminal of the third resistor is connected to the output terminal of the voltage output circuit.

4. The signal acquisition circuit as described in claim 2, characterized in that, When the signal sampling circuit is an analog-to-digital converter, the voltage output circuit reuses the sub-circuit used for output voltage in the analog-to-digital converter, and the reference circuit output terminal of the signal sampling circuit is connected to the input terminal of the signal amplification circuit as the output terminal of the voltage output circuit.

5. The signal acquisition circuit as described in claim 2, characterized in that, Also includes: The signal preprocessing circuit has its input terminal connected to the output terminal of the gap sensor and its output terminal connected to the signal adjustment circuit. It is configured to filter out interference signals in the gap signal and transmit the processed signal to the signal adjustment circuit.

6. The signal acquisition circuit as described in claim 5, characterized in that, The signal preprocessing circuit includes at least: a fifth resistor and a first capacitor; The first end of the fifth resistor is connected to the output end of the gap sensor, the second end of the fifth resistor is connected to the output end of the signal adjustment circuit and the first end of the first capacitor, and the second end of the first capacitor is grounded.

7. The signal acquisition circuit as described in any one of claims 2-6, characterized in that, Also includes: A voltage protection circuit, whose input terminal is connected to the output terminal of the signal amplification circuit and whose output terminal is connected to the input terminal of the signal sampling circuit, is configured to turn on when the voltage of the adjustment signal is greater than a preset threshold, so as to reduce the adjustment signal to a preset clamping voltage and output it to the signal sampling circuit.

8. The signal acquisition circuit as described in claim 7, characterized in that, The voltage protection circuit includes: At least two clamping diodes are provided. The anode of the first clamping diode is connected to the output terminal of the signal amplification circuit, the cathode of the first clamping diode is connected to the anode of the second clamping diode, and the cathode of the second clamping diode is connected to the input terminal of the signal sampling circuit.

9. The signal acquisition circuit as described in claim 8, characterized in that, The voltage protection circuit also includes: At least one sixth resistor is disposed between the cathode of the second clamping diode and the input terminal of the signal sampling circuit.

10. A magnetic levitation train, characterized in that, It includes a gap sensor and a signal acquisition circuit as described in any one of claims 1-9.

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