Signal processing circuit of miniature high-frequency ultrasonic distance measuring sensor

Abstract

The utility model relates to the technical field of sensor circuits, in particular to a signal processing circuit of a miniature high-frequency ultrasonic distance measuring sensor, which mainly comprises an ultrasonic driving module, a band-pass amplification module, a logarithmic detection amplification module and a detection output amplification module which are sequentially connected. The band-pass amplification module is used for amplifying the signal; the logarithmic detection amplification module is used for carrying out second amplification processing on the signal transmitted by the band-pass amplification module, and the detection output amplification module is used for carrying out third amplification processing on the signal transmitted by the logarithmic detection amplification module. The detection blind area can be further reduced through multiple times of amplification processing of the modules and judgment of existence of secondary echoes.

Description

Technical Field

[0001] This utility model relates to the field of sensor circuit technology, and more specifically, to a signal processing circuit for a miniature high-frequency ultrasonic ranging sensor. Background Technology

[0002] Miniature high-frequency ultrasonic ranging sensors are devices that use ultrasonic technology to measure distances and are widely used in industrial automation, robotics, and automotive driver assistance systems. Their core principle is to emit high-frequency ultrasonic pulses and receive the reflected echoes, calculating the target distance using the speed of sound in air and the time difference. With the development of microelectronics technology, sensors have gradually become miniaturized and operate at higher frequencies, improving measurement accuracy and response speed. However, current sensors suffer from large blind zones, resulting in poor performance that needs further improvement. Utility Model Content

[0003] The purpose of this invention is to provide a signal processing circuit for a miniature high-frequency ultrasonic ranging sensor to solve the problem of large blind zones in existing technologies.

[0004] This utility model is achieved through the following technical solution:

[0005] A signal processing circuit for a miniature high-frequency ultrasonic ranging sensor includes an ultrasonic driving module, a bandpass amplification module, a logarithmic detection amplification module, and a detection output amplification module connected in sequence.

[0006] The ultrasonic drive circuit is used to drive the entire signal processing circuit to work.

[0007] The bandpass amplifier module is used to amplify the signal and transmit it to the logarithmic detector amplifier module;

[0008] The logarithmic detector amplifier module is used to amplify the signal transmitted from the bandpass amplifier module a second time and transmit it to the detector output amplifier module.

[0009] The detector output amplification module is used to amplify the signal transmitted from the logarithmic detector amplification module for a third time and transmit it to the MCU processor for calculation and output.

[0010] Preferably, the ultrasonic driving module includes a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a first transistor, a second transistor, an ultrasonic sensor, a first diode, and a second diode.

[0011] One end of the first resistor is connected to one end of the second capacitor and one end of the third capacitor simultaneously; the other end of the second capacitor is connected to one end of the first transistor, the third resistor and the fourth resistor simultaneously; and the other end of the third capacitor is connected to one end of the second transistor and one end of the second resistor simultaneously.

[0012] The other end of the third resistor is connected to one end of the second transistor and one end of the fourth capacitor, and the other end of the fourth resistor is connected to one end of the first capacitor, the first transistor and one end of the fifth resistor.

[0013] The other end of the second resistor is connected to one end of the second transistor, the sixth resistor, the ultrasonic sensor, and the first diode, and the other end of the fourth capacitor is connected to one end of the second diode and the sixth resistor.

[0014] The other end of the first transistor is connected to the second diode, the seventh resistor, and one end of the ultrasonic sensor simultaneously, and the other end of the seventh resistor is connected to the first diode.

[0015] Preferably, the bandpass amplifier module includes an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor, and a first operational amplifier unit;

[0016] The eighth resistor is connected to one end of the ninth resistor, the ninth capacitor, the sixth capacitor, and the twelfth resistor simultaneously; the other end of the ninth resistor is connected to one end of the sixth capacitor and the first operational amplifier unit simultaneously; the other end of the ninth capacitor is connected to one end of the fifth capacitor, the first diode, and the seventh resistor simultaneously; the other end of the sixth capacitor is also connected to the twelfth resistor, and the other end of the twelfth resistor is connected to one end of the fifth capacitor and the first operational amplifier unit simultaneously.

[0017] The tenth resistor is connected to one end of the seventh and eighth capacitors simultaneously. The other end of the seventh capacitor is connected to one end of the eleventh resistor and one end of the first operational amplifier unit simultaneously. The other end of the eighth capacitor is connected to one end of the eleventh resistor and one end of the first operational amplifier unit simultaneously.

[0018] Preferably, the logarithmic detector amplification module includes a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a sixteenth capacitor, and an amplification processor;

[0019] One end of the tenth capacitor is connected to the amplifier processor, and the other end is simultaneously connected to one end of the first operational amplifier unit, the eleventh resistor, and the eighth capacitor.

[0020] One end of the thirteenth resistor is connected to the amplifier processor, and the other end is simultaneously connected to the fourteenth resistor, the fourteenth capacitor, and another port of the amplifier processor.

[0021] The other end of the fourteenth capacitor is connected to the sixteenth resistor;

[0022] One end of the eleventh capacitor is connected to the amplifier processor, and the other end is connected to both the twelfth capacitor and another port of the amplifier processor. The other end of the twelfth capacitor is connected to the amplifier processor.

[0023] One end of the fifteenth resistor is connected to the amplifier processor, and the other end is connected to the fifteenth capacitor and the sixteenth capacitor.

[0024] Preferably, the detector output amplification module includes a seventeenth resistor, an eighteenth resistor, and a second operational amplifier unit;

[0025] One end of the seventeenth resistor is connected to both the second operational amplifier unit and one end of the sixteenth resistor, and the other end is connected to the output terminal of the second operational amplifier unit.

[0026] One end of the eighteenth resistor is connected to one end of the fifteenth capacitor, the twelfth capacitor, the eleventh capacitor, and the amplifier processor, while the other end is connected to one end of the sixteenth capacitor and the second operational amplifier unit.

[0027] Preferably, the ultrasonic sensor is an ultrasonic transducer.

[0028] Preferably, it also includes a power supply module, which is connected to the ultrasonic drive module, the bandpass amplification module, the logarithmic detector amplification module, and the detector output amplification module, respectively.

[0029] Preferably, it also includes an output interface module, which is connected to the detector output amplification module.

[0030] The technical solution of this utility model has at least the following advantages and beneficial effects:

[0031] The structure of this invention mainly includes an ultrasonic drive module, a bandpass amplification module, a logarithmic detection amplification module, and a detection output amplification module connected in sequence. The bandpass amplification module amplifies the signal; the logarithmic detection amplification module amplifies the signal transmitted from the bandpass amplification module a second time; and the detection output amplification module amplifies the signal transmitted from the logarithmic detection amplification module a third time. Through multiple amplification processes by these modules, and by determining the presence or absence of the signal through secondary echoes, the detection blind zone can be further reduced. Attached Figure Description

[0032] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.

[0033] Figure 1 This is a schematic diagram of the ultrasonic drive module of this utility model;

[0034] Figure 2 This is a schematic diagram of the bandpass amplifier module of this utility model;

[0035] Figure 3 This is a schematic diagram of the logarithmic detector amplification module of this utility model;

[0036] Figure 4 This is a schematic diagram of the detector output amplification module of this utility model.

[0037] Icons: R12 - First resistor, R13 - Second resistor, R14 - Third resistor, R15 - Fourth resistor, R16 - Fifth resistor, R17 - Sixth resistor, R18 - Seventh resistor, R19 - Eighth resistor, R20 - Ninth resistor, R21 - Tenth resistor, R22 - Eleventh resistor, R23 - Twelfth resistor, R24 - Thirteenth resistor, R25 - Fourteenth resistor, R26 - Fifteenth resistor, R27 - Sixteenth resistor, R8 - Seventeenth resistor, R9 - Eighteenth resistor, C20 - First capacitor, C21 - Second capacitor, C22 - Third capacitor C23 - Fourth capacitor, C24 - Fifth capacitor, C25 - Sixth capacitor, C26 - Seventh capacitor, C27 - Eighth capacitor, C36 - Ninth capacitor, C28 - Tenth capacitor, C29 - Eleventh capacitor, C30 - Twelfth capacitor, C31 - Thirteenth capacitor, C32 - Fourteenth capacitor, C34 - Fifteenth capacitor, C37 - Sixteenth capacitor, Q2 - First transistor, Q3 - Second transistor, T1 - Ultrasonic sensor, D5 - First diode, D6 - Second diode, U5 - First operational amplifier unit, U7 - Second operational amplifier unit, U6 - Amplifier processor. Detailed Implementation

[0038] 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, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0039] Please refer to Figures 1-4 The present invention provides a signal processing circuit for a miniature high-frequency ultrasonic ranging sensor, comprising an ultrasonic driving module, a bandpass amplification module, a logarithmic detection amplification module, and a detection output amplification module connected in sequence.

[0040] The ultrasonic drive circuit is used to drive the entire signal processing circuit to work.

[0041] The bandpass amplifier module is used to amplify the signal and transmit it to the logarithmic detector amplifier module;

[0042] The logarithmic detector amplifier module is used to amplify the signal transmitted from the bandpass amplifier module a second time and transmit it to the detector output amplifier module.

[0043] The detector output amplification module is used to amplify the signal transmitted from the logarithmic detector amplification module for a third time and transmit it to the MCU processor for calculation and output.

[0044] The structure of this invention mainly includes an ultrasonic drive module, a bandpass amplification module, a logarithmic detection amplification module, and a detection output amplification module connected in sequence. The bandpass amplification module amplifies the signal; the logarithmic detection amplification module amplifies the signal transmitted from the bandpass amplification module a second time; and the detection output amplification module amplifies the signal transmitted from the logarithmic detection amplification module a third time. Through multiple amplification processes by these modules, and by determining the presence or absence of the signal through secondary echoes, the detection blind zone can be further reduced.

[0045] In one exemplary embodiment of this utility model, the ultrasonic driving module includes a first resistor R12, a second resistor R13, a third resistor R14, a fourth resistor R15, a fifth resistor R16, a sixth resistor R17, a seventh resistor R18, a first capacitor C20, a second capacitor C21, a third capacitor C22, a fourth capacitor C23, a first transistor Q2, a second transistor Q3, an ultrasonic sensor T1, a first diode D5, and a second diode D6.

[0046] One end of the first resistor R12 is connected to one end of the second capacitor C21 and the third capacitor C22. The other end of the second capacitor C21 is connected to one end of the first transistor Q2, the third resistor R14 and the fourth resistor R15. The other end of the third capacitor C22 is connected to one end of the second transistor Q3 and the second resistor R13.

[0047] The other end of the third resistor R14 is connected to one end of the second transistor Q3 and the fourth capacitor C23, and the other end of the fourth resistor R15 is connected to one end of the first capacitor C20, the first transistor Q2 and the fifth resistor R16.

[0048] The other end of the second resistor R13 is connected to the second transistor Q3, the sixth resistor R17, the ultrasonic sensor T1 and one end of the first diode D5 at the same time; the other end of the fourth capacitor C23 is connected to the second diode D6 and one end of the sixth resistor R17 at the same time.

[0049] The other end of the first transistor Q2 is connected to the second diode D6, the seventh resistor R18, and one end of the ultrasonic sensor T1. The other end of the seventh resistor R18 is connected to the first diode D5.

[0050] In one exemplary embodiment of this utility model, the bandpass amplifier module includes an eighth resistor R19, a ninth resistor R20, a tenth resistor R21, an eleventh resistor R22, a twelfth resistor R23, a fifth capacitor C24, a sixth capacitor C25, a seventh capacitor C26, an eighth capacitor C27, a ninth capacitor C36, and a first operational amplifier unit U5.

[0051] The eighth resistor R19 is connected to one end of the ninth resistor R20, the ninth capacitor C36, the sixth capacitor C25, and the twelfth resistor R23; the other end of the ninth resistor R20 is connected to one end of the sixth capacitor C25 and the first operational amplifier unit U5; the other end of the ninth capacitor C36 is connected to one end of the fifth capacitor C24, the first diode D5, and the seventh resistor R18; the other end of the sixth capacitor C25 is also connected to the twelfth resistor R23, and the other end of the twelfth resistor R23 is connected to one end of the fifth capacitor C24 and the first operational amplifier unit U5.

[0052] The tenth resistor R21 is connected to one end of the seventh capacitor C26 and the eighth capacitor C27. The other end of the seventh capacitor C26 is connected to one end of the eleventh resistor R22 and the first operational amplifier unit U5. The other end of the eighth capacitor C27 is connected to one end of the eleventh resistor R22 and the first operational amplifier unit U5.

[0053] For the non-inverting input, the input value is used, where the ninth capacitor C36 is initially not electrically connected. The seventh resistor R18, the fifth capacitor C24, and the twelfth resistor R23 form a high-pass filter. To ensure no input attenuation, the seventh resistor R18 is much smaller than the twelfth resistor R23. The fifth capacitor C24 and the twelfth resistor R23 together form the cutoff frequency, which is not greater than the transducer frequency. For the inverting input, a band-pass filter is formed.

[0054] In one exemplary embodiment of this utility model, the logarithmic detector amplification module includes a thirteenth resistor R24, a fourteenth resistor R25, a fifteenth resistor R26, a sixteenth resistor R27, a tenth capacitor C28, an eleventh capacitor C29, a twelfth capacitor C30, a thirteenth capacitor C31, a fourteenth capacitor C32, a fifteenth capacitor C34, a sixteenth capacitor C37, and an amplification processor U6.

[0055] One end of the tenth capacitor C28 is connected to the amplifier processor U6, and the other end is simultaneously connected to the first operational amplifier unit U5, the eleventh resistor R22, and one end of the eighth capacitor C27.

[0056] One end of the thirteenth resistor R24 ​​is connected to the amplifier processor U6, and the other end is connected to the fourteenth resistor R25, the fourteenth capacitor C32, and another port of the amplifier processor U6.

[0057] The other end of the fourteenth capacitor C32 is connected to the sixteenth resistor R27;

[0058] One end of the eleventh capacitor C29 is connected to the amplifier processor U6, and the other end is connected to both the twelfth capacitor C30 and another port of the amplifier processor U6. The other end of the twelfth capacitor C30 is connected to the amplifier processor U6.

[0059] One end of the fifteenth resistor R26 is connected to the amplifier processor U6, and the other end is connected to the fifteenth capacitor C34 and the sixteenth capacitor C37.

[0060] The tenth capacitor C28 and the eleventh capacitor C29 are connected by a 50Ω resistor to form an impedance matching circuit. For input filtering, the OFLT has a built-in 33pF capacitor, keeping the operating frequency at 1MHz. For every 300pF increase, the bandwidth decreases by a factor of 10. The twelfth capacitor C30, with a value of 1nF, provides a cutoff frequency of 1kHz. For output filtering, BF IN can be adjusted by adding capacitors to allow the output to quickly return to the reference point. A built-in 3KΩ resistor allows a 2.7nF capacitor to reach 20kHz, while a 2.7µF capacitor can reach 20Hz.

[0061] In one exemplary embodiment of this utility model, the detector output amplification module includes a seventeenth resistor, an eighteenth resistor R9, and a second operational amplifier unit U7;

[0062] One end of the seventeenth resistor is connected to one end of the second operational amplifier unit U7 and one end of the sixteenth resistor R27, and the other end is connected to the output terminal of the second operational amplifier unit U7.

[0063] One end of the eighteenth resistor R9 is connected to one end of the fifteenth capacitor C34, the twelfth capacitor C30, the eleventh capacitor C29 and the amplifier processor U6, and the other end is connected to one end of the sixteenth capacitor C37 and the second operational amplifier unit U7.

[0064] The sixteenth resistor R27 and the seventeenth resistor form an inverting amplifier, while the fifteenth resistor R26, the sixteenth capacitor C37, the fifteenth capacitor C34, and the eighteenth resistor R9 form a bandpass filter. To ensure the design matches the theoretical values, the resistor values ​​are kept as small as possible.

[0065] In addition, it includes a power supply module, which is connected to the ultrasonic drive module, bandpass amplifier module, logarithmic detector amplifier module, and detector output amplifier module. It also includes an output interface module, which is connected to the detector output amplifier module.

[0066] It also includes an MCU main control circuit. The MCU generates a 300kHz ultrasonic drive signal and performs calculations on the signal after it is amplified by the signal processing circuit. It controls the output of NPN or PNP switching signals by the switching chip through SPI communication. The MCU model is STM32G030F8P6.

[0067] To avoid overheating, the power supplies for the MCU and signal conditioning circuit are separated. A dedicated LDO powers the signal conditioning circuit, while the LDO of the digital input chip powers the MCU. This solution uses a digital DC-DC converter to transform the input voltage to 6V, and then uses two LDOs to generate 5V and 3.3V power supplies respectively, powering the signal conditioning circuit and the MCU.

[0068] Based on the above structure, the working principle of this circuit is as follows:

[0069] The ultrasonic signal is generated by the MCU as a 3.3V 300K pulse signal, which is sent from the first resistor R12 to the ultrasonic drive module and the bandpass amplifier module for amplification. It generates a pulse signal of about twice the power supply voltage at both ends of the ultrasonic sensor T1. The transducer converts it into a 300K ultrasonic signal and emits it in front of the sensor. When the sound wave signal encounters an obstacle, it is reflected back to the transducer, which then converts it into an electrical signal and sends it to the subsequent amplification circuit for amplification.

[0070] The amplified signal is sent to the logarithmic detector amplification module through the tenth capacitor C28 for logarithmic detection and amplification. The logarithmically detected and amplified signal is sent to the detector output amplification module through the fifteenth resistor R26 and the sixteenth capacitor C37. The signal amplified by the detector output amplification module is then sent to the MCU for calculation, processing, and output.

[0071] The models of the relevant hardware involved in this solution have been listed. Figure 1-4 The winning bidders will not be listed in detail here.

[0072] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. A signal processing circuit of a miniature high-frequency ultrasonic distance measuring sensor, characterized by, The ultrasonic wave driving module, the band pass amplification module, the logarithmic detection amplification module and the detection output amplification module are sequentially connected. An ultrasonic wave driving circuit is used to drive the whole signal processing circuit to work. The band pass amplification module is used to amplify the signal and transmit it to the logarithmic detection amplification module. The logarithmic detection amplification module is used to amplify the signal transmitted by the band pass amplification module for the second time and transmit it to the detection output amplification module. The detection output amplification module is used to amplify the signal transmitted by the logarithmic detection amplification module for the third time and transmit it to the MCU processor for calculation and output.

2. The signal processing circuit of a miniature high-frequency ultrasonic ranging sensor according to claim 1, characterized in that, The ultrasonic wave driving module comprises a first resistor, a second resistor, a third resistor, a fourth resistor, a fifth resistor, a sixth resistor, a seventh resistor, a first capacitor, a second capacitor, a third capacitor, a fourth capacitor, a first triode, a second triode, an ultrasonic wave sensor, a first diode and a second diode. One end of the first resistor is connected with one end of the second capacitor and the third capacitor, the other end of the second capacitor is connected with one end of the first triode, the third resistor and the fourth resistor, and the other end of the third capacitor is connected with one end of the second triode and the second resistor. The other end of the third resistor is connected with one end of the second triode and the fourth capacitor, and the other end of the fourth resistor is connected with one end of the first capacitor, the first triode and the fifth resistor. The other end of the second resistor is connected with one end of the second triode, the sixth resistor, the ultrasonic wave sensor and the first diode, and the other end of the fourth capacitor is connected with one end of the second diode and the sixth resistor. The other end of the first triode is connected with one end of the second diode, the seventh resistor and the ultrasonic wave sensor, and the other end of the seventh resistor is connected with the first diode.

3. The signal processing circuit of a miniature high-frequency ultrasonic ranging sensor according to claim 2, characterized in that, The band pass amplification module comprises an eighth resistor, a ninth resistor, a tenth resistor, an eleventh resistor, a twelfth resistor, a fifth capacitor, a sixth capacitor, a seventh capacitor, an eighth capacitor, a ninth capacitor and a first operational amplifier unit. One end of the eighth resistor is connected with one end of the ninth resistor, the ninth capacitor, the sixth capacitor and the twelfth resistor, the other end of the ninth resistor is connected with one end of the sixth capacitor and the first operational amplifier unit, the other end of the ninth capacitor is connected with one end of the fifth capacitor, the first diode and the seventh resistor, the other end of the sixth capacitor is also connected with the twelfth resistor, and the other end of the twelfth resistor is connected with one end of the fifth capacitor and the first operational amplifier unit. The tenth resistor is connected with one end of the seventh capacitor and the eighth capacitor, the other end of the seventh capacitor is connected with one end of the eleventh resistor and the first operational amplifier unit, and the other end of the eighth capacitor is connected with one end of the eleventh resistor and the first operational amplifier unit.

4. The signal processing circuit of a miniature high-frequency ultrasonic ranging sensor according to claim 3, wherein The logarithmic detection amplification module comprises a thirteenth resistor, a fourteenth resistor, a fifteenth resistor, a sixteenth resistor, a tenth capacitor, an eleventh capacitor, a twelfth capacitor, a thirteenth capacitor, a fourteenth capacitor, a fifteenth capacitor, a sixteenth capacitor and an amplification processor. One end of the tenth capacitor is connected with the amplification processor, and the other end is connected with the first operational amplifier unit, the eleventh resistor and one end of the eighth capacitor simultaneously; One end of the thirteenth resistor is connected with the amplification processor, and the other end is connected with the fourteenth resistor, the fourteenth capacitor and the other port of the amplification processor simultaneously; The other end of the fourteenth capacitor is connected with the sixteenth resistor; One end of the eleventh capacitor is connected with the amplification processor, and the other end is connected with the twelfth capacitor and the other port of the amplification processor simultaneously, and the other end of the twelfth capacitor is connected with the amplification processor; One end of the fifteenth resistor is connected with the amplification processor, and the other end is connected with the fifteenth capacitor and the sixteenth capacitor.

5. The signal processing circuit of a miniature high-frequency ultrasonic ranging sensor according to claim 4, wherein, The wave detection output amplification module comprises a seventeenth resistor, an eighteenth resistor and a second operational amplifier unit; One end of the seventeenth resistor is connected with the second operational amplifier unit and one end of the sixteenth resistor simultaneously, and the other end is connected with the output end of the second operational amplifier unit; One end of the eighteenth resistor is connected with the fifteenth capacitor, the twelfth capacitor, the eleventh capacitor and one end of the amplification processor simultaneously, and the other end is connected with the sixteenth capacitor and one end of the second operational amplifier unit simultaneously.

6. The signal processing circuit of a miniature high-frequency ultrasonic ranging sensor according to claim 5, wherein, The ultrasonic sensor is an ultrasonic transducer.

7. The signal processing circuit of a miniature high-frequency ultrasonic ranging sensor according to claim 6, characterized in that, Further comprising a power module, the power module is connected with the ultrasonic driving module, the band pass amplification module, the logarithmic wave detection amplification module and the wave detection output amplification module respectively.

8. The signal processing circuit of a miniature high-frequency ultrasonic ranging sensor according to claim 6, characterized in that, Further comprising an output interface module, the output interface module is connected with the wave detection output amplification module.

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