A single-channel TDC speed measurement system

Abstract

The utility model discloses a single -channel TDC speed measurement system belongs to the technical field of TDC speed measurement, and this speed measurement system includes: comparator, high low level control port is connected to the negative input of comparator, and the positive input of comparator is connected with input signal channel, high -speed switch -over switch, high -speed switch -over switch links to each other with the output of comparator, and the stop signal end and start signal end of high -speed switch -over switch are accessed to TDC chip respectively, to reach through internal high -speed switch -over switch, and the two sinusoidal wave signals of magnetic speed measurement sensor single -channel output are separated to satisfy the signal detection demand of TDC chip.

Description

Technical Field

[0001] This utility model belongs to the technical field of TDC speed measurement, specifically, it relates to a single-channel TDC speed measurement system. Background Technology

[0002] The TDC time-to-digital converter can be used to accurately measure the output signal of an atomic clock, helping to calibrate the atomic clock to achieve higher time accuracy. Atomic clocks are currently the most accurate timekeeping devices, and their accuracy is crucial for fields such as satellite navigation, communication, and scientific research.

[0003] By using a TDC time-to-digital converter to measure the time interval of an atomic clock with high precision, frequency deviations of the atomic clock can be detected in a timely manner and adjusted to ensure that the atomic clock always maintains high accuracy.

[0004] Radar can determine the speed of a target by measuring the frequency changes of the target's reflected signal. In this process, TDC can accurately measure the time changes of the signal, thereby calculating the target's speed and acceleration.

[0005] High-speed, high-precision radar velocity measurement (TDC) can improve the accuracy of radar in measuring target velocity, especially for high-speed moving targets such as aircraft and missiles. This is of great significance for military defense, industrial production, scientific research, traffic control, and other fields.

[0006] In the 1970s, TDC (Time-to-Digital Converter) technology was primarily based on integrated circuits, converting time into digital data by counting and processing clock signals. However, early TDC chips had low integration levels, and their accuracy and speed needed improvement.

[0007] With the rapid development of semiconductor technology, the performance of TDC (Transmitter Digital Converter) has been continuously improved. The integration density of chips has gradually increased, and circuit design has been continuously optimized, resulting in significant improvements in the measurement accuracy and speed of TDC. At the same time, the application scope of TDC has gradually expanded, beginning to be used in aerospace, communications, and other fields.

[0008] Its working principle is as follows: The speed of the bullet is calculated by measuring the time it takes for the bullet to pass between two known points during its flight. A high-speed camera or photoelectric sensor is typically used to record the bullet's trajectory. Timing starts when the bullet passes the first point and stops when it passes the second point. Based on the distance and time difference between the two points, the bullet's speed can be calculated, and the analog Start and Stop signals are recorded respectively.

[0009] In existing technologies, Start and Stop signals are detected separately through dual channels. However, when the magnetic speed sensor connects its two induction coils in series and has only one signal output interface, TDC speed measurement cannot be achieved. Therefore, existing TDC speed measurement has significant limitations in circuit design.

[0010] Therefore, there is an urgent need to develop a circuit system that can realize single-channel TDC speed measurement. Utility Model Content

[0011] In view of this, in order to solve the above-mentioned problems in the existing technology, the purpose of this utility model is to provide a single-channel TDC speed measurement system so as to separate the two sinusoidal signals output by the single channel of the magnetic speed sensor through an internal high-speed switching switch to meet the signal detection requirements of the TDC chip.

[0012] The technical solution adopted in this utility model is: a single-channel TDC speed measurement system, which includes:

[0013] The comparator has a negative input terminal connected to a high / low level control port and a positive input terminal connected to an input signal channel.

[0014] A high-speed switching switch is connected to the output of the comparator, and the Stop signal terminal and Start signal terminal of the high-speed switching switch are respectively connected to the TDC chip.

[0015] Furthermore, the high / low level control port is connected to the I / O control port of the MCU microcontroller.

[0016] Furthermore, the input signal channel includes a positive signal channel and a negative signal channel. The negative signal channel is connected in parallel with a second resistor and a transient TVS diode via a first resistor. The other ends of the second resistor and the transient TVS diode are connected in parallel and then connected to the positive input terminal of the comparator via a third resistor.

[0017] Furthermore, the high / low level control port is connected to the negative input terminal of the comparator through an RC filter circuit.

[0018] Furthermore, the speed measurement system also includes:

[0019] An external signal input port is provided, which is connected to a signal relay. The common terminal COM1 and common terminal COM2 of the signal relay are connected to the external signal input port, and the two normally closed contacts of the signal relay are connected to the negative signal channel CH1R- and the positive signal channel CH1R+, respectively.

[0020] Furthermore, the speed measurement system also includes:

[0021] A gate driver, the input of which is connected to the output of the comparator.

[0022] Furthermore, the output of the comparator is connected to a fourth resistor and a fifth resistor. The fourth resistor is connected to the input of the gate driver, and the other end of the fifth resistor is grounded.

[0023] The beneficial effects of this utility model are as follows:

[0024] 1. The single-channel TDC speed measurement system provided by this utility model generates a weak current when the object being measured passes through the electromagnetic induction sensor. The input current signal is amplified by the comparator, converted into a voltage signal, and shaped to form a pulse signal as the output signal. The output signal is separated into two sine wave signals by the built-in high-speed switching switch and transmitted to the Start and Stop signal ports respectively, thereby realizing single-channel TDC speed measurement. Attached Figure Description

[0025] Figure 1 This utility model provides a signal conditioning circuit for a single-channel TDC speed measurement system.

[0026] Figure 2 This utility model provides the external input signal circuit for a single-channel TDC speed measurement system.

[0027] Figure 3 This is a circuit diagram of the MCU microcontroller in the single-channel TDC speed measurement system provided by this utility model;

[0028] Figure 4 This utility model provides an internal high-speed switching circuit in a single-channel TDC speed measurement system.

[0029] Figure 5 This is a circuit diagram of the TDC chip in the single-channel TDC speed measurement system provided by this utility model. Detailed Implementation

[0030] The embodiments of this application are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar modules or modules having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and are only used to explain this application, and should not be construed as limiting this application. Rather, the embodiments of this application include all variations, modifications, and equivalents falling within the spirit and scope of the appended claims.

[0031] Example 1

[0032] like Figures 1-5As shown, this embodiment provides a single-channel TDC speed measurement system. TDC stands for Time-to-Digital Converter, and its core function is to convert the time information of analog signals into digital form for accurate measurement and processing. The speed measurement system in this embodiment mainly comprises a comparator, a high-speed switching switch, and a gate driver, among other components. Its specific design is as follows:

[0033] The current signal collected by the electromagnetic induction sensor from the object under test is input through an external signal input port. This external signal input port is connected to a signal relay, model G6K-2F-Y-TR DC5, which is an ultra-miniature 5V driven double-pole double-throw signal relay suitable for low-current, high-reliability switching scenarios. The common terminals COM1 and COM2 of this signal relay are connected to the external signal input port, and the two normally closed contacts of the signal relay are connected to the negative signal channel CH1R- and the positive signal channel CH1R+, respectively. Simultaneously, the positive terminal of the signal relay coil is connected to a 5V power supply, and the negative terminal of the coil is connected in series with transistor Q1 and resistor R39 to the PA11 port of the MCU microcontroller. A diode D7 is connected in series between the positive and negative terminals of the signal relay coil.

[0034] To amplify the acquired current signal, a comparator is also configured. The negative input of the comparator is connected to a high / low level control port, which is connected to the I / O control port PA4 of the MCU microcontroller. Control signals are then sent from the MCU microcontroller's I / O control port. Specifically, the high / low level control port is connected to the negative input of the comparator through an RC filter circuit, which consists of resistors R29 and C20. On the other hand, the positive input of the comparator is connected to an input signal channel, which includes a positive signal channel CH1R+ and a negative signal channel CH1R-. The negative signal channel CH1R- is connected in parallel with resistor R26, along with resistor R23 and a transient TVS diode. The other end of resistor R23 and the transient TVS diode are connected in parallel and then connected to the positive input of the comparator through resistor R21. The comparator model is GS8746U-TR, which is a low-power, high-speed voltage comparator.

[0035] To achieve switching between Stop and Start signals on a single-channel circuit, this system also includes a high-speed switch. The high-speed switch is connected to the output of the comparator, and its Stop and Start signal terminals are respectively connected to the TDC chip. Specifically, the high-speed switch is model 1P1G3157QDCKRQ1. Its A port is connected to the comparator's output, its B1 and B2 ports are connected to the TDC chip's START and STOP1 ports respectively, its S port is connected to the MCU microcontroller's PA12 port, and its VCC terminal is connected to a 3.3V power supply and grounded through capacitor C17. The response speed of this high-speed switch is 0.3ns.

[0036] The speed measurement system also includes a gate driver, specifically a high-speed low-side gate driver chip, model SL27517, which is specifically designed to drive key components of power switching devices (such as MOSFETs, IGBTs, GaN, SiC, etc.). The input terminal IN+ of the gate driver is connected to the output terminal of the comparator through a series resistor R22, and the output terminal of the comparator is grounded through a series resistor R20. The VDD terminal of the gate driver is connected to the power supply, and the input terminal IN- of the gate driver is grounded.

[0037] The single-channel TDC velocity measurement system described above works as follows: It calculates the velocity by measuring the time it takes for a bullet to travel between two known points during its flight. Typically, a high-speed camera or photoelectric sensor is used to record the bullet's trajectory. Timing starts when the bullet passes the first point and stops when it passes the second point. The bullet's velocity can be calculated based on the distance and time difference between the two points. However, this solution uses a magnetic induction point, along with an internal high-speed switching switch to record the analog Start and Stop signals respectively.

[0038] The system initializes the TDC (MS1030) chip, uses the SPI communication protocol to configure the TDC chip to be triggered by the rising edge of the Start and Stop signals, with the number of signal pulses being N. Subsequently, the MCU microcontroller pin PA0 is configured for advanced timer input capture function, PA4 is configured for analog voltage output function, and PA11 and PA12 are configured for push-pull output function.

[0039] During system operation, pull the PA11 and PA12 pins of the MCU low, set the high-speed switch to conduct at ports A and B1, keep the signal relay at the CH1R+ signal input port, and connect CH1R- to GND. Only capture the pulse signal of CH1R+. The CH1R+ signal passes through the signal relay, is filtered by RC, and then enters the comparator section. The voltage comparison pin of the comparator is directly connected to the MCU pin PA4. Set the voltage of PA4 to an appropriate range; currently, it is set to 0.8V. This way, signals below 0.8V will be filtered out, and only the target signal CH1R+ above 0.8V can pass through the comparator and be amplified to 3.3V. At this point, the signal can be named CH1TTLQ+, and CH1TTLQ+ is connected to the high-speed switch input port A.

[0040] Before the first CH1TTLQ+ pulse arrives, CH1TTLQ+ is directly connected to the MCU microcontroller pin PA0 and the high-speed switch port A. During system operation, ports A and B1 are conducting, and port B1 is connected to the START pin of the TDC chip. At this time, it is equivalent to CH1TTLQ+ being connected to the START pin of the TDC chip. When CH1TTLQ+ pulses for the first time, the TDC chip detects the rising edge of the START signal and starts timing, recording this moment as T1. Simultaneously, the input capture function on pin PA0 also detects the rising edge, triggering an input capture interrupt. In the interrupt, PA12 is pulled high, setting the high-speed switch to conduct between ports A and B2. Port B2 is connected to the STOP1 pin of the TDC chip. At this time, it is equivalent to CH1TTLQ+ being connected to the STOP1 pin of the TDC chip.

[0041] In subsequent pulses, since the CH1TTLQ+ signals are all connected to the STOP1 pin of the TDC chip, each rising edge of the subsequent Stop signal is recorded by the TDC chip, and the time is denoted as Tn. After the pulse count reaches a set number, the TDC chip's result register can be read using SPI communication to obtain data D0 to Dn. Data D0 to Dn is the difference between the Nth Stop signal time Tn and the START signal time T1. For the TDC chip, precise timing data Dn is obtained by accurately counting the difference between the rising edge time Tn of the signal and the adjacent reference clock, and by coarsely counting the number of reference clock cycles between signals. Therefore, the measurement time of the Nth Stop signal needs to record the time Tc1 of the Start signal relative to the rising edge of the next reference clock, the time Tc2 of the Stop signal relative to the rising edge of the next reference clock, the number of reference clock cycles count between the Start and Stop signals, and the reference clock cycle Tref. Finally, the time of the Nth Stop signal relative to the Start signal is obtained by Dn = Tref × (count) + (Tc1 - Tc2). Finally, the moving speed data of the object to be measured is calculated from the time interval data. ΔV is the velocity of the object being measured, where D n For the Nth Stop signal time, D n-1 For N-1 Stop signal times, S is the measurement path.

[0042] It should be noted that any process or method description in the flowchart or otherwise described herein can be understood as representing a module, segment, or portion of code comprising one or more executable instructions for implementing a particular logical function or process, and the scope of the preferred embodiments of this application includes additional implementations in which functions may be performed not in the order shown or discussed, including in substantially the same manner or in the reverse order of the functions involved, as should be understood by those skilled in the art to which the embodiments of this application pertain.

[0043] It should be understood that various parts of this application can be implemented using hardware, software, firmware, or a combination thereof. In the above embodiments, multiple steps or methods can be implemented using software or firmware stored in memory and executed by a suitable instruction execution system. For example, if implemented in hardware, as in another embodiment, it can be implemented using any one or a combination of the following techniques known in the art: discrete logic circuits having logic gates for implementing logical functions on data signals, application-specific integrated circuits (ASICs) having suitable combinational logic gates, programmable gate arrays (PGAs), field-programmable gate arrays (FPGAs), etc.

[0044] Those skilled in the art will understand that all or part of the steps of the methods in the above embodiments can be implemented by a program instructing related hardware. The program can be stored in a computer-readable storage medium, and when executed, the program includes one or a combination of the steps of the method embodiments.

[0045] Furthermore, the functional units in the various embodiments of this application can be integrated into a processing module, or each unit can exist physically separately, or two or more units can be integrated into a module. The integrated module can be implemented in hardware or as a software functional module. If the integrated module is implemented as a software functional module and sold or used as an independent product, it can also be stored in a computer-readable storage medium.

[0046] The storage media mentioned above can be read-only memory, disk, or optical disk, etc.

[0047] Although embodiments of this application have been shown and described above, it is understood that the above embodiments are exemplary and should not be construed as limiting this application. Those skilled in the art can make changes, modifications, substitutions and variations to the above embodiments within the scope of this application.

Claims

1. A single channel TDC speed measurement system characterized by, The speed measurement system includes: The comparator has a negative input terminal connected to a high / low level control port and a positive input terminal connected to an input signal channel. A high-speed switching switch is connected to the output of the comparator, and the Stop signal terminal and Start signal terminal of the high-speed switching switch are respectively connected to the TDC chip.

2. The single channel TDC speed measurement system of claim 1, wherein, The high / low level control port is connected to the IO control port of the MCU microcontroller.

3. The single channel TDC speed measurement system of claim 1, wherein, The input signal channel includes a positive signal channel and a negative signal channel. The negative signal channel is connected in parallel with a second resistor and a transient TVS diode via a first resistor. The other ends of the second resistor and the transient TVS diode are connected in parallel and then connected to the positive input terminal of the comparator via a third resistor.

4. The single channel TDC velocity measurement system of claim 1, wherein, The high / low level control port is connected to the negative input terminal of the comparator through an RC filter circuit.

5. The single channel TDC velocity measurement system of claim 1, wherein, The speed measurement system also includes: An external signal input port is provided, which is connected to a signal relay. The common terminal COM1 and common terminal COM2 of the signal relay are connected to the external signal input port, and the two sets of normally closed contacts of the signal relay are connected to the negative signal channel CH1R- and the positive signal channel CH1R+, respectively.

6. The single channel TDC velocity measurement system of claim 1, wherein, The speed measurement system also includes: A gate driver, the input of which is connected to the output of the comparator.

7. The single channel TDC speed measurement system of claim 6, wherein, The output of the comparator is connected to a fourth resistor and a fifth resistor. The fourth resistor is connected to the input of the gate driver, and the other end of the fifth resistor is grounded.

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