Ultrasonic receiving and transmitting integrated ultrasonic distance measuring circuit and ultrasonic receiving and transmitting integrated ultrasonic distance measuring method

Abstract

The invention discloses an ultrasonic receiving and transmitting integrated ultrasonic ranging circuit and method. A driving unit drives an ultrasonic receiving and transmitting integrated unit to send an ultrasonic signal; when the ultrasonic signal encounters an obstacle, an echo signal is received through the ultrasonic receiving and transmitting integrated unit; performing amplification processing on the echo signal through an amplification unit; performing filtering processing on the amplified echo signal through a filtering unit; and the filtered echo signal is sent to the micro-control unit through the diode envelope detection unit, so that the micro-control unit carries out distance measurement according to the filtered echo signal. By adding the small-size ultrasonic receiving and transmitting integrated unit on the sound box, comprising the first amplifying unit, the second amplifying unit, the first filtering unit, the second filtering unit and the diode envelope detection unit, a traditional large-size ultrasonic horn and a driving circuit thereof can be replaced, and the overall size of the product is effectively reduced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of ultrasonic ranging, in particular to an ultrasonic ranging circuit and method with integrated ultrasonic transmitting and receiving. BACKGROUND

[0002] Ultrasonic ranging technology is widely used in various intelligent devices, especially in the field of smart speakers. This technology measures the distance of an object by transmitting ultrasonic waves and receiving the reflected echo signals. In smart speakers, it is usually used for environmental perception, distance estimation, and user interaction functions.

[0003] Currently, ultrasonic ranging in the field of smart speakers usually uses an audio amplifier to drive an ultrasonic speaker, and measures the distance by collecting the reflected echo through a microphone. However, this solution requires a large-sized ultrasonic speaker and microphone assembly, resulting in an increase in the overall volume of the product.

[0004] Therefore, how to reduce the overall volume of the product has become a problem that needs to be solved in the field. SUMMARY

[0005] The present application provides an ultrasonic ranging circuit and method with integrated ultrasonic transmitting and receiving, aiming to reduce the overall volume of the product.

[0006] To achieve the above-mentioned purpose, the present application provides the following technical solutions:

[0007] An ultrasonic ranging circuit with integrated ultrasonic transmitting and receiving, comprising: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2, a driving unit, an ultrasonic transmitting and receiving unit, an amplifying unit, a filtering unit, and a diode envelope detection unit.

[0008] One end of the first resistor R1 is connected to one end of the second resistor R2, the other end of the first resistor R1 is grounded, and the other end of the second resistor R2 is connected to a first end of the driving unit.

[0009] A second end of the driving unit is connected to a first end of the ultrasonic transmitting and receiving unit, and a third end of the driving unit is connected to a second end of the ultrasonic transmitting and receiving unit.

[0010] A third end of the ultrasonic transmitting and receiving unit is connected to one end of the first capacitor C1, and the other end of the first capacitor C1 is connected to one end of the amplifying unit.

[0011] The other end of the amplification unit is connected with one end of the third resistor R3, the other end of the third resistor R3 is connected with one end of the filter unit, the other end of the filter unit is connected with one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected with one end of the second capacitor C2, and the other end of the second capacitor C2 is connected with one end of the diode envelope detection unit.

[0012] The driving unit sends an ultrasonic signal through the ultrasonic transceiving integrated unit, receives a return signal through the ultrasonic transceiving integrated unit when the ultrasonic signal encounters an obstacle, amplifies the return signal through the amplification unit, filters the amplified return signal through the filter unit, and sends the filtered return signal to the micro control unit through the diode envelope detection unit, so that the micro control unit measures the distance according to the filtered return signal.

[0013] Optionally, the amplification unit comprises a third capacitor C3, a fifth resistor R5, a first amplification unit and a second amplification unit.

[0014] One end of the first amplification unit is connected with the other end of the first capacitor C1, and the other end of the first amplification unit is connected with one end of the third capacitor C3.

[0015] The other end of the third capacitor C3 is connected with one end of the fifth resistor R5, the other end of the fifth resistor R5 is connected with one end of the second amplification unit, and the other end of the second amplification unit is connected with one end of the third resistor R3.

[0016] Optionally, the filter unit comprises a first filter unit, a second filter unit and a sixth resistor R6.

[0017] One end of the first filter unit is connected with the other end of the third resistor R3, and the other end of the first filter unit is connected with one end of the sixth resistor R6.

[0018] The other end of the sixth resistor R6 is connected with one end of the second filter unit, and the other end of the second filter unit is connected with one end of the fourth resistor R4.

[0019] Optionally, the driving unit comprises a seventh resistor R7, a fourth capacitor C4, a transformer and a field effect tube D1.

[0020] The gate of the field effect tube D1 is connected with the other end of the second resistor R2, the drain of the field effect tube D1 is grounded, and the source of the field effect tube D1 is connected with the first primary coil of the transformer.

[0021] The second primary coil of the transformer is connected with one end of the seventh resistor R7, the common end of the connection is connected with one end of the fourth capacitor C4, the other end of the fourth capacitor C4 is grounded, and the other end of the seventh resistor R7 is connected with a power supply;

[0022] The first secondary coil of the transformer is connected with a first end of the ultrasonic transceiving integrated unit, and the second secondary coil of the transformer is connected with a second end of the ultrasonic transceiving integrated unit, and the common end of the connection is grounded.

[0023] Optionally, the ultrasonic transceiving integrated unit comprises a first diode Q1, a second diode Q2, a third diode Q3, a fourth diode Q4, an eighth resistor R8, a ninth resistor R9 and an ultrasonic probe.

[0024] The anode of the first diode Q1 is connected with the cathode of the second diode Q2, and the common end of the connection is connected with the second end of the driving unit.

[0025] The anode of the second diode Q2 is connected with the cathode of the first diode Q1, and the common end of the connection is connected with one end of the eighth resistor R8, one end of the ninth resistor R9 and one end of the ultrasonic probe, and the other end of the ultrasonic probe is connected with the third end of the driving unit.

[0026] The other end of the eighth resistor R8 is grounded, the other end of the ninth resistor R9 is connected with the anode of the third diode Q3, the common end of the connection is connected with one end of the first capacitor C1 and the cathode of the fourth diode Q4, the anode of the fourth diode Q4 is connected with the cathode of the third diode Q3, and the common end of the connection is grounded.

[0027] Optionally, the first amplifying unit comprises a fifth capacitor C5, a sixth capacitor C6, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13 and a first operational amplifier U1A.

[0028] The fifth capacitor C5 and the tenth resistor R10 are connected in parallel between the inverting input end and the output end of the first operational amplifier U1A, and the output end of the first operational amplifier U1A is connected with one end of the second capacitor C2.

[0029] The forward input end of the first operational amplifier U1A is connected with the other end of the eleventh resistor R11, the common end of the connection is connected with one end of the twelfth resistor R12.

[0030] The reverse input end of the first operational amplifier U1A is connected with one end of the thirteenth resistor R13, the other end of the thirteenth resistor R13 is connected with one end of the sixth capacitor C6, and the other end of the sixth capacitor C6 is grounded.

[0031] Optionally, the second amplifying unit comprises a seventh capacitor C7, a fourteenth resistor R14 and a second operational amplifier U2A.

[0032] The seventh capacitor C7 and the fourteenth resistor R14 are connected in parallel between the reverse input end and the output end of the second operational amplifier U2A, the reverse input end of the second operational amplifier U2A is connected with the other end of the third resistor R3, and the output end of the second operational amplifier U2A is connected with one end of the fourth resistor R4.

[0033] The positive power supply of the second operational amplifier U2A is connected with a power supply, and the negative power supply of the second operational amplifier U2A is grounded.

[0034] Optionally, the second operational amplifier U2A is specifically a single power supply operational amplifier.

[0035] Optionally, the first filtering unit comprises an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10, a fifteenth resistor R15, a sixteenth resistor R16 and a third operational amplifier U3A.

[0036] One end of the fifteenth resistor R15 is connected with one end of the eighth capacitor C8, and the common end connected thereby is connected with the other end of the fourth resistor R4 and one end of the ninth capacitor C9.

[0037] The other end of the ninth capacitor C9 is connected with the reverse input end of the third operational amplifier U3A, and the common end connected thereby is connected with one end of the sixteenth resistor R16 and one end of the tenth capacitor C10.

[0038] The other end of the eighth capacitor C8 is connected with the output end of the third operational amplifier U3A, and the common end connected thereby is connected with the other end of the sixteenth resistor R16 and the other end of the tenth capacitor C10.

[0039] The output end of the third operational amplifier U3A is connected with one end of the fifth resistor R5.

[0040] Optionally, the second filtering unit comprises an eleventh capacitor C11, a twelfth capacitor C12, a thirteenth capacitor C13, a seventeenth resistor R17, an eighteenth resistor R18 and a fourth operational amplifier U4A.

[0041] One end of the seventeenth resistor R17 is connected with one end of the eleventh capacitor C11, and the common end connected therewith is connected with the other end of the fifth resistor R5 and one end of the twelfth capacitor C12;

[0042] The other end of the twelfth capacitor C12 is connected with the inverting input end of the fourth operational amplifier U4A, and the common end connected therewith is connected with one end of the eighteenth resistor R18 and one end of the thirteenth capacitor C13;

[0043] The positive power supply of the fourth operational amplifier U4A is connected with a power supply, and the negative power supply of the fourth operational amplifier U4A is grounded;

[0044] The other end of the eleventh capacitor C11 is connected with the output end of the fourth operational amplifier U4A, and the common end connected therewith is connected with the other end of the eighteenth resistor R18 and the other end of the thirteenth capacitor C13;

[0045] The output end of the fourth operational amplifier U4A is connected with one end of the sixth resistor R6.

[0046] Optionally, the diode envelope detection unit comprises a fifth diode Q5, a sixth diode Q6, a fourteenth capacitor C14, a nineteenth resistor R19 and a twentieth resistor R20;

[0047] The negative electrode of the fifth diode Q5 is connected with the positive electrode of the sixth diode Q6, and the common end connected therewith is connected with the other end of the sixth resistor R6;

[0048] The positive electrode of the fifth diode Q5 is connected with one end of the nineteenth resistor R19, and the common end connected therewith is connected with one end of the fourteenth capacitor C14 and grounded;

[0049] The negative electrode of the sixth diode Q6 is connected with one end of the twentieth resistor R20, and the common end connected therewith is connected with the other end of the fourteenth capacitor C14 and the other end of the nineteenth resistor R19.

[0050] An ultrasonic ranging method of an ultrasonic transmitting-receiving integrated ultrasonic ranging circuit, applied to the ultrasonic transmitting-receiving integrated ultrasonic ranging circuit, comprising:

[0051] The driving unit drives the ultrasonic transmitting-receiving integrated unit to send an ultrasonic signal;

[0052] When the ultrasonic signal meets an obstacle, the ultrasonic transmitting-receiving integrated unit receives a return signal;

[0053] The amplifying unit amplifies the return signal;

[0054] Filter the amplified echo signal through the filter unit;

[0055] Send the filtered echo signal to the micro control unit through the diode envelope detection unit, so that the micro control unit measures distance according to the filtered echo signal.

[0056] The technical scheme provided in the application, the driving unit drives the ultrasonic transceiving integrated unit to send ultrasonic signals; when the ultrasonic signals meet an obstacle, the ultrasonic transceiving integrated unit receives echo signals; the amplification unit amplifies the echo signals; the filter unit filters the amplified echo signals; the diode envelope detection unit sends the filtered echo signals to the micro control unit, so that the micro control unit measures distance according to the filtered echo signals. By adding a small-volume ultrasonic transceiving integrated unit, including a first amplification unit, a second amplification unit, a first filter unit, a second filter unit and a diode envelope detection unit, on the sound box, the traditional large-volume ultrasonic horn and its driving circuit can be replaced, and the overall volume of the product is effectively reduced. BRIEF DESCRIPTION OF DRAWINGS

[0057] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without creative labor.

[0058] Figure 1 A first architecture schematic diagram of an ultrasonic transceiving integrated ultrasonic ranging circuit provided by the embodiment of the present application;

[0059] Figure 2 A second architecture schematic diagram of an ultrasonic transceiving integrated ultrasonic ranging circuit provided by the embodiment of the present application;

[0060] Figure 3 A third architecture schematic diagram of an ultrasonic transceiving integrated ultrasonic ranging circuit provided by the embodiment of the present application;

[0061] Figure 4 A fourth architecture schematic diagram of an ultrasonic transceiving integrated ultrasonic ranging circuit provided by the embodiment of the present application;

[0062] Figure 5 A fifth architecture schematic diagram of an ultrasonic transceiving integrated ultrasonic ranging circuit provided by the embodiment of the present application;

[0063] Figure 6 A sixth architecture schematic diagram of an ultrasonic transceiving integrated ultrasonic ranging circuit provided by the embodiment of the present application;

[0064] Figure 7 A seventh schematic diagram of an ultrasonic transmitting-receiving integrated ultrasonic ranging circuit is provided for the embodiment of the present application;

[0065] Figure 8 An eighth schematic diagram of an ultrasonic transmitting-receiving integrated ultrasonic ranging circuit is provided for the embodiment of the present application;

[0066] Figure 9 A ninth schematic diagram of an ultrasonic transmitting-receiving integrated ultrasonic ranging circuit is provided for the embodiment of the present application;

[0067] Figure 10 A tenth schematic diagram of an ultrasonic transmitting-receiving integrated ultrasonic ranging circuit is provided for the embodiment of the present application;

[0068] Figure 11 A flowchart of an ultrasonic transmitting-receiving integrated ultrasonic ranging method is provided for the embodiment of the present application;

[0069] Figure 12 An analog filter circuit simulation schematic diagram is provided for the embodiment of the present application.

[0070] Reference signs:

[0071] R1 - first resistor; R2 - second resistor; R3 - third resistor; R4 - fourth resistor; R5 - fifth resistor; R6 - sixth resistor; C1 - first capacitor; C2 - second capacitor; C3 - third capacitor; 11 - driving unit; 12 - ultrasonic transceiving unit; 13 - amplifying unit; 14 - filtering unit; 15 - diode envelope detection unit; C3 - third capacitor; R5 - fifth resistor; 21 - first amplifying unit; 22 - second amplifying unit; 31 - first filtering unit; 32 - second filtering unit; R6 - sixth resistor; R7 - seventh resistor; C4 - fourth capacitor; D1 - transformer field effect transistor; Q1 - first diode; Q2 - second diode; Q3 - third diode; Q4 - fourth diode; R8 - eighth resistor; R9 - ninth resistor; C5 - fifth capacitor; C6 - sixth capacitor; R10 - tenth resistor; R11 - eleventh resistor; R12 - twelfth resistor; R13 - thirteenth resistor; U1A - first operational amplifier; C7 - seventh capacitor; R14 - fourteenth resistor; U2A - second operational amplifier; C8 - eighth capacitor; C9 - ninth capacitor; C10 - tenth capacitor; R15 - fifteenth resistor; R16 - sixteenth resistor; U3A - third operational amplifier; C11 - eleventh capacitor; C12 - twelfth capacitor; C13 - thirteenth capacitor; R17 - seventeenth resistor; R18 - eighteenth resistor; U4A - fourth operational amplifier; Q5 - fifth diode; Q6 - sixth diode; C14 - fourteenth capacitor; R19 - nineteenth resistor; R20 - twentieth resistor. DETAILED DESCRIPTION

[0072] The technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application. Obviously, the described embodiments are only part of the embodiments of the present application, rather than all the embodiments of the present application. Based on the embodiments in the present application, all other embodiments obtained by those skilled in the art without creative work fall within the scope of protection of the present application.

[0073] In the present application, the terms "comprising", "containing" or any other variant thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such a process, method, article or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another same element in the process, method, article or device including the element.

[0074] As Figure 1The diagram shown is a schematic of the architecture of an ultrasonic ranging circuit integrating ultrasonic transceiver provided in an embodiment of this application. The ultrasonic ranging circuit includes: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a fifth resistor R5, a sixth resistor R6, a first capacitor C1, a second capacitor C2, a third capacitor C3, a driving unit 11, an ultrasonic transceiver unit 12, an amplification unit 13, a filtering unit 14, and a diode envelope detection unit 15.

[0075] One end of the first resistor R1 is connected to one end of the second resistor R2, the other end of the first resistor R1 is grounded, and the other end of the second resistor R2 is connected to the first end of the drive unit.

[0076] The second end of the drive unit 11 is connected to the first end of the ultrasonic transceiver unit, and the third end of the drive unit is connected to the second end of the ultrasonic transceiver unit.

[0077] The third end of the ultrasonic transceiver unit 12 is connected to one end of the first capacitor C1, and the other end of the first capacitor C1 is connected to one end of the amplification unit.

[0078] The other end of the amplification unit 13 is connected to one end of the third resistor R3, the other end of the third resistor R3 is connected to one end of the filter unit, the other end of the filter unit 14 is connected to one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is connected to one end of the diode envelope detection unit 15.

[0079] The drive unit 11 drives the ultrasonic transceiver unit 12 to send ultrasonic signals; when the ultrasonic signal encounters an obstacle, it receives the echo signal through the ultrasonic transceiver unit 12; the echo signal is amplified by the amplification unit 13; the amplified echo signal is filtered by the filtering unit 14; and the filtered echo signal is sent to the microcontroller unit by the diode envelope detector unit 15 so that the microcontroller unit can perform distance measurement based on the filtered echo signal.

[0080] It is understandable that the microcontroller unit controls the drive unit 11 to drive the ultrasonic transceiver unit 12 to work through the periodic oscillation signal generated by the MOS transistor (i.e., field-effect transistor), thereby exciting an ultrasonic signal (i.e., inverse piezoelectric effect) in the ultrasonic transceiver unit 12.

[0081] Furthermore, combined with Figure 1 For the content shown, please refer to [link / reference]. Figure 2 The amplification unit 13 includes: a third capacitor C3, a fifth resistor R5, a first amplification unit 21, and a second amplification unit 22.

[0082] One end of the first amplification unit 21 is connected to the other end of the first capacitor C1, and the other end of the first amplification unit 21 is connected to one end of the third capacitor C3.

[0083] The other end of the third capacitor C3 is connected to one end of the fifth resistor R5, the other end of the fifth resistor R5 is connected to one end of the second amplification unit 22, and the other end of the second amplification unit 22 is connected to one end of the third resistor R3.

[0084] Furthermore, combined with Figure 2 See the content shown. Figure 3 The filter unit 14 includes: a first filter unit 31, a second filter unit 32, and a sixth resistor R6.

[0085] One end of the first filter unit 31 is connected to the other end of the third resistor R3, and the other end of the first filter unit 31 is connected to one end of the sixth resistor R6.

[0086] The other end of the sixth resistor R6 is connected to one end of the second filter unit 32, and the other end of the second filter unit 32 is connected to one end of the fourth resistor R4.

[0087] Furthermore, combined with Figure 3 For the content shown, please refer to [link / reference]. Figure 4 The drive unit 11 includes: a seventh resistor R7, a fourth capacitor C4, a transformer, and a field-effect transistor D1;

[0088] The gate of the field-effect transistor D1 is connected to the other end of the second resistor R2, the drain of the field-effect transistor D1 is grounded, and the source of the field-effect transistor D1 is connected to the first primary coil of the transformer.

[0089] The second primary coil of the transformer is connected to one end of the seventh resistor R7, and the common terminal of the connection is connected to one end of the fourth capacitor C4. The other end of the fourth capacitor C4 is grounded, and the other end of the seventh resistor R7 is connected to the power supply.

[0090] The primary coil of the transformer is connected to the first end of the ultrasonic transceiver unit 12, and the secondary coil of the transformer is connected to the second end of the ultrasonic transceiver unit 12. The common terminal of their connection is grounded.

[0091] Understandably, a one-cycle ultrasonic signal is generated by a field-effect transistor and then loaded onto the ultrasonic transceiver unit 12.

[0092] Furthermore, combined with Figure 4 See the content shown. Figure 5 The ultrasonic transceiver unit 12 includes: a first diode Q1, a second diode Q2, a third diode Q3, a fourth diode Q4, an eighth resistor R8, a ninth resistor R9, and an ultrasonic probe;

[0093] The positive electrode of the first diode Q1 is connected with the negative electrode of the second diode Q2, and the common end connected with the second end of the driving unit;

[0094] The positive electrode of the second diode Q2 is connected with the negative electrode of the first diode Q1, and the common end connected with one end of the eighth resistor R8, one end of the ninth resistor R9 and one end of the ultrasonic probe, the other end of the ultrasonic probe is connected with the third end of the driving unit;

[0095] The other end of the eighth resistor R8 is grounded, the other end of the ninth resistor R9 is connected with the positive electrode of the third diode Q3, and the common end connected with one end of the first capacitor C1 and the negative electrode of the fourth diode Q4, the positive electrode of the fourth diode Q4 is connected with the negative electrode of the third diode Q3, and the common end connected is grounded.

[0096] It can be understood that a periodic ultrasonic signal is generated by the field effect transistor (MOS tube), and is loaded on the ultrasonic probe. When the ultrasonic signal encounters an obstacle, a return signal is generated. These return signals are generated on the ultrasonic probe through the piezoelectric effect and can be used for subsequent ranging analysis to determine the distance of the obstacle.

[0097] Further, in combination with the content shown in Figure 5 , see Figure 6 , the first amplification unit 21 includes: a fifth capacitor C5, a sixth capacitor C6, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13 and a first operational amplifier U1A.

[0098] The fifth capacitor C5 and the tenth resistor R10 are connected in parallel between the reverse input end and the output end of the first operational amplifier U1A, and the output end of the first operational amplifier U1A is connected with one end of the second capacitor C2.

[0099] The positive input end of the first operational amplifier U1A is connected with the other end of the eleventh resistor R11, and the common end connected with one end of the twelfth resistor R12.

[0100] The reverse input end of the first operational amplifier U1A is connected with one end of the thirteenth resistor R13, the other end of the thirteenth resistor R13 is connected with one end of the sixth capacitor C6, and the other end of the sixth capacitor C6 is grounded.

[0101] Among them, the first operational amplifier U1A is used to perform the first signal amplification processing on the return signal, mainly for amplifying the positive half cycle and the negative half cycle in the return signal.

[0102] Further, in combination with the content shown in Figure 6 , see Figure 7The second amplification unit 22 includes: a seventh capacitor C7, a fourteenth resistor R14, and a second operational amplifier U2A.

[0103] The seventh capacitor C7 and the fourteenth resistor R14 are connected in parallel to the inverting input and output terminals of the second operational amplifier U2A. The inverting input terminal of the second operational amplifier U2A is connected to the other end of the third resistor R3, and the output terminal of the second operational amplifier U2A is connected to one end of the fourth resistor R4.

[0104] The positive power supply of the second operational amplifier U2A is connected to the power supply, and the negative power supply of the second operational amplifier U2A is grounded.

[0105] It should be noted that since the amplification of the echo signal by the first operational amplifier U1A is small and insufficient to be detected, the upper half-cycle signal of the echo signal after the first amplification is amplified by the second operational amplifier U2A.

[0106] Furthermore, combined with Figure 7 See the content shown. Figure 8 The first filter unit 31 includes: an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10, a fifteenth resistor R15, a sixteenth resistor R16, and a third operational amplifier U3A.

[0107] One end of the fifteenth resistor R15 is connected to one end of the eighth capacitor C8, and the common terminal of the connection is connected to the other end of the fourth resistor R4 and one end of the ninth capacitor C9.

[0108] The other end of the ninth capacitor C9 is connected to the inverting input of the third operational amplifier U3A, and its common terminal is connected to one end of the sixteenth resistor R16 and one end of the tenth capacitor C10.

[0109] The other end of the eighth capacitor C8 is connected to the output of the third operational amplifier U3A, and the other end of the sixteenth resistor R16, which is connected to the common terminal, is connected to the other end of the tenth capacitor C10.

[0110] The output of the third operational amplifier U3A is connected to one end of the fifth resistor R5.

[0111] It is understandable that the amplified echo information is filtered by the first filtering unit 31 (i.e., the bandpass filter) to remove noise and interference components from the signal.

[0112] Furthermore, combined with Figure 8 See the content shown. Figure 9 The second filter unit 32 includes: an eleventh capacitor C11, a twelfth capacitor C12, a thirteenth capacitor C13, a seventeenth resistor R17, an eighteenth resistor R18, and a fourth operational amplifier U4A.

[0113] One end of the seventeenth resistor R17 is connected to one end of the eleventh capacitor C11, and the common terminal of their connection is connected to the other end of the fifth resistor R5 and one end of the twelfth capacitor C12.

[0114] The other end of the twelfth capacitor C12 is connected to the inverting input of the fourth operational amplifier U4A, and its common terminal is connected to one end of the eighteenth resistor R18 and one end of the thirteenth capacitor C13.

[0115] The positive power supply of the fourth operational amplifier U4A is connected to the power supply, and the negative power supply of the fourth operational amplifier U4A is grounded.

[0116] The other end of the eleventh capacitor C11 is connected to the output terminal of the fourth operational amplifier U4A, and the other end of the eighteenth resistor R18, which is connected to the common terminal, is connected to the other end of the thirteenth capacitor C13.

[0117] The output of the fourth operational amplifier U4A is connected to one end of the sixth resistor R6.

[0118] Optionally, the first operational amplifier U1A, the third operational amplifier U3A, and the fourth operational amplifier U4A are specifically single-supply operational amplifiers.

[0119] Understandably, the secondary filtering of the echo signal after the first filtering by the second filtering unit 32 is to further remove noise or unwanted signal components in different frequency ranges. Each stage of the bandpass filter usually has a specific frequency bandwidth and filtering characteristics. The first round of filtering may remove broadband noise or irrelevant frequencies, while the second round of filtering is more refined, focusing on extracting more accurate signal frequency bands.

[0120] Furthermore, combined with Figure 9 See the content shown. Figure 10 The diode envelope detection unit 15 includes: a fifth diode Q5, a sixth diode Q6, a fourteenth capacitor C14, a nineteenth resistor R19, and a twentieth resistor R20.

[0121] The cathode of the fifth diode Q5 is connected to the anode of the sixth diode Q6, and their common terminal is connected to the other end of the sixth resistor R6.

[0122] The positive terminal of the fifth diode Q5 is connected to one end of the nineteenth resistor R19, and its common terminal is connected to one end of the fourteenth capacitor C14 and grounded.

[0123] The negative terminal of the sixth diode Q6 is connected to one end of the twentieth resistor R20, and its common terminal is connected to the other end of the fourteenth capacitor C14 and the other end of the nineteenth resistor R19.

[0124] The diode envelope detection unit 15 processes the filtered echo signal to form an analog echo, and sends the analog echo to the micro control unit, so that the micro control unit calculates the distance according to the analog echo.

[0125] It should be noted that through the above content, the embodiment can realize the following beneficial effects:

[0126] 1、The signal processing part of the circuit uses a single power supply rail-to-rail operational amplifier. Compared with the audio amplifier and microphone back sampling circuit on the market, this design greatly optimizes the driving and signal processing circuit, saving circuit space.

[0127] 2、Compared with the audio amplifier and microphone back sampling circuit, this design does not require complex software algorithm support, and the program control is more concise. The micro control unit can be shared with the system level chip, without the need to additionally increase the signal processing unit, reducing the system cost and complexity.

[0128] 3、The bandpass filter of the ultrasonic signal processing part has stronger anti-interference ability than the microphone signal acquisition system, which can effectively improve the stability and accuracy of the signal.

[0129] 4、The circuit has good expansibility and can be applied to many fields such as car reversing radar, material level measurement, liquid level measurement, etc. In addition, according to the frequency of the ultrasonic probe, the peripheral resistance and capacitance elements can be adjusted to form an adaptive bandpass filter, meeting different application requirements.

[0130] As Figure 11 shown, a flow chart of an ultrasonic ranging method provided by the embodiment of the application is applied to the ultrasonic transceiving integrated ultrasonic ranging circuit of any of the above Figures 1 to 10 The method comprises the following steps:

[0131] S1101: The driving unit drives the ultrasonic transceiving integrated unit to send an ultrasonic signal.

[0132] The micro control unit controls the driving unit to generate a periodic oscillation signal through the field effect transistor, so as to load the ultrasonic probe in the ultrasonic transceiving integrated unit, and send the ultrasonic signal through the ultrasonic probe.

[0133] S1102: When the ultrasonic signal encounters an obstacle, the ultrasonic transceiving integrated unit receives an echo signal.

[0134] When the ultrasonic signal encounters an obstacle, the ultrasonic probe in the ultrasonic transceiving integrated unit receives an echo signal, and the echo signal generates a piezoelectric effect on the ultrasonic probe.

[0135] S1103: The echo signal is amplified by an amplification unit.

[0136] The amplification unit includes a first amplification unit and a second amplification unit.

[0137] It can be understood that the echo signal will usually be affected by factors such as propagation loss and environmental interference, resulting in signal attenuation. By amplifying through the first amplification unit and the second amplification unit, the strength of the echo signal can be effectively improved, so that the subsequent processing unit can more easily capture useful signals.

[0138] S1104: The amplified echo signal is filtered by a filtering unit.

[0139] The filtering unit includes a first filtering unit and a second filtering unit.

[0140] Optionally, the first filtering unit and the second filtering unit include but are not limited to a band-pass filter.

[0141] Specifically, referring to Figure 12 a band-pass filter circuit simulation schematic diagram, Figure 12 a band-pass filter with a center frequency of about 5KHz~10MHz, and a center frequency of 500KHz. The peripheral resistance and capacitance device parameters of the band-pass filter can be adjusted according to the use frequency of the ultrasonic probe to adjust the center frequency.

[0142] S1105: The filtered echo signal is sent to a micro control unit by a diode envelope detection unit, so that the micro control unit measures the distance according to the filtered echo signal.

[0143] The micro control unit needs to process the echo signal through a special algorithm. First, the micro control unit sets a reference voltage (for example: 0.8V), and when the amplitude of the echo signal exceeds the reference voltage, the detection process is triggered. Then, the micro control unit completes the wave emission operation and adds aftershock delay, and then starts the timer to count. When the echo signal is received, the timer stops counting. According to the speed of sound of ultrasonic wave in air (constant), the distance of the obstacle can be calculated by the formula S=V×T. Wherein, S is the distance, V is the speed of sound wave in medium (in this case, air), T is the time required from transmitting ultrasonic signal to receiving echo signal, which is usually measured by the micro control unit through the timer.

[0144] In summary, by adding a small volume of ultrasonic transceiver unit on the sound box, the amplification unit, the filtering unit and the diode envelope detection unit can replace the traditional large volume ultrasonic horn and its driving circuit, not only effectively reducing the overall volume of the product, but also reusing the chip of the sound box itself, without the need for additional micro control unit, thereby saving the cost of the product.

[0145] The various embodiments described in this specification are intended to be illustrative only and alterations and / or modifications to the illustrated embodiments can readily occur to those skilled in the art. Accordingly, the phraseology "at least one of A and B should be construed in the sense that A and B include at least one of A and B, but not the possibility of the presence of all of the members, in the sense of "and / or", unless otherwise indicated herein. Moreover, where a choice of means or elements is expressly contemplated by this specification (for example, where a parameter is "selected from the group consisting of A, B, and C"), then "at least one of A and B" is understood to allow for "A but not B", "B but not A", and "A and B" as well as the possibility of the presence of all of the members of the group. The various embodiments described in this specification can be described in the general context of computer-executable instructions of a computer program that runs on computer hardware. Computer-executable instructions include, but are not limited to, computer program code, routines, subroutines, programs, applications, software modules, microcode, bytecode, firmware, macros, interpreters, and machine code. Such computer-executable instructions or computer program can be stored, compiled, or interpreted to run on one or more computers, processors, or other hardware. As such, the term "computer" should be taken to encompass any of these possibilities and should not be limited to a general purpose computer. The above-described systems and system embodiments are merely illustrative and not restrictive, wherein the units described as separate components may or may not be physically separate, and the components shown as units may or may not be physical units, i.e., they may be located in one place or distributed over multiple network units. Some or all of the modules can be selected according to actual needs to achieve the purposes of the embodiments. Those skilled in the art can understand and implement without creative labor.

[0146] Those skilled in the art will further appreciate that the units and algorithm steps of the examples described in conjunction with the embodiments disclosed herein can be implemented in electronic hardware, computer software, or a combination of both. To clearly illustrate the interchangeability of hardware and software, the components and steps of the examples have been described in general terms hereinabove as being generally described in terms of functionality. Whether such functionality is implemented as hardware or software depends on the particular application and design constraints imposed on the overall system. Those skilled in the art can implement the described functionality in varying ways for each particular application, but such implementation should not be interpreted to change the scope of the present application.

[0147] The above description of disclosed embodiments enables a person skilled in the art to implement or use the application. Various modifications to these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the application. Therefore, the application will not be limited to the embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. An ultrasonic ranging circuit integrating ultrasonic transceiver, characterized in that, The ultrasonic ranging circuit includes: a first resistor R1, a second resistor R2, a third resistor R3, a fourth resistor R4, a first capacitor C1, a second capacitor C2, a driving unit, an ultrasonic transceiver unit, an amplification unit, a filtering unit, and a diode envelope detection unit. One end of the first resistor R1 is connected to one end of the second resistor R2, the other end of the first resistor R1 is grounded, and the other end of the second resistor R2 is connected to the first end of the driving unit. The second end of the driving unit is connected to the first end of the ultrasonic transceiver unit, and the third end of the driving unit is connected to the second end of the ultrasonic transceiver unit. The third end of the ultrasonic transceiver unit is connected to one end of the first capacitor C1, and the other end of the first capacitor C1 is connected to one end of the amplification unit. The other end of the amplification unit is connected to one end of the third resistor R3, the other end of the third resistor R3 is connected to one end of the filtering unit, the other end of the filtering unit is connected to one end of the fourth resistor R4, the other end of the fourth resistor R4 is connected to one end of the second capacitor C2, and the other end of the second capacitor C2 is connected to one end of the diode envelope detection unit. The driving unit transmits ultrasonic signals by driving an ultrasonic transceiver unit; when the ultrasonic signal encounters an obstacle, it receives an echo signal through the ultrasonic transceiver unit; the echo signal is amplified by the amplification unit; the amplified echo signal is filtered by the filtering unit; and the filtered echo signal is sent to the microcontroller unit by the diode envelope detector unit, so that the microcontroller unit can perform distance measurement based on the filtered echo signal.

2. The circuit according to claim 1, characterized in that, The amplification unit includes: a third capacitor C3, a fifth resistor R5, a first amplification unit, and a second amplification unit; One end of the first amplification unit is connected to the other end of the first capacitor C1, and the other end of the first amplification unit is connected to one end of the third capacitor C3. The other end of the third capacitor C3 is connected to one end of the fifth resistor R5, the other end of the fifth resistor R5 is connected to one end of the second amplification unit, and the other end of the second amplification unit is connected to one end of the third resistor R3.

3. The circuit according to claim 1, characterized in that, The filtering unit includes: a first filtering unit, a second filtering unit, and a sixth resistor R6; One end of the first filter unit is connected to the other end of the third resistor R3, and the other end of the first filter unit is connected to one end of the sixth resistor R6. The other end of the sixth resistor R6 is connected to one end of the second filter unit, and the other end of the second filter unit is connected to one end of the fourth resistor R4.

4. The circuit according to claim 1, characterized in that, The driving unit includes: a seventh resistor R7, a fourth capacitor C4, a transformer, and a field-effect transistor D1; The gate of the field-effect transistor D1 is connected to the other end of the second resistor R2, the drain of the field-effect transistor D1 is grounded, and the source of the field-effect transistor D1 is connected to the first primary coil of the transformer. The second primary coil of the transformer is connected to one end of the seventh resistor R7, and the common terminal of the connection is connected to one end of the fourth capacitor C4. The other end of the fourth capacitor C4 is grounded, and the other end of the seventh resistor R7 is connected to the power supply. The primary coil of the transformer is connected to the first end of the ultrasonic transceiver unit, and the secondary coil of the transformer is connected to the second end of the ultrasonic transceiver unit. The common terminal of their connection is grounded.

5. The circuit according to claim 1, characterized in that, The ultrasonic transceiver unit includes: a first diode Q1, a second diode Q2, a third diode Q3, a fourth diode Q4, an eighth resistor R8, a ninth resistor R9, and an ultrasonic probe; The positive terminal of the first diode Q1 is connected to the negative terminal of the second diode Q2, and their common terminal is connected to the second terminal of the driving unit. The positive terminal of the second diode Q2 is connected to the negative terminal of the first diode Q1, and their common terminal is connected to one end of the eighth resistor R8, one end of the ninth resistor R9 and one end of the ultrasonic probe. The other end of the ultrasonic probe is connected to the third end of the driving unit. The other end of the eighth resistor R8 is grounded, and the other end of the ninth resistor R9 is connected to the positive terminal of the third diode Q3. The common terminal of the connection is connected to one end of the first capacitor C1 and the negative terminal of the fourth diode Q4. The positive terminal of the fourth diode Q4 is connected to the negative terminal of the third diode Q3, and the common terminal of the connection is grounded.

6. The circuit according to claim 2, characterized in that, The first amplification unit includes: a fifth capacitor C5, a sixth capacitor C6, a tenth resistor R10, an eleventh resistor R11, a twelfth resistor R12, a thirteenth resistor R13, and a first operational amplifier U1A; The fifth capacitor C5 and the tenth resistor R10 are connected in parallel at the inverting input and output terminals of the first operational amplifier U1A, and the output terminal of the first operational amplifier U1A is connected to one end of the second capacitor C2. The positive input terminal of the first operational amplifier U1A is connected to the other end of the eleventh resistor R11, and the common terminal of the connection is connected to one end of the twelfth resistor R12. The inverting input terminal of the first operational amplifier U1A is connected to one end of the thirteenth resistor R13, the other end of the thirteenth resistor R13 is connected to one end of the sixth capacitor C6, and the other end of the sixth capacitor C6 is grounded.

7. The circuit according to claim 2, characterized in that, The second amplification unit includes: a seventh capacitor C7, a fourteenth resistor R14, and a second operational amplifier U2A; The seventh capacitor C7 and the fourteenth resistor R14 are connected in parallel to the inverting input and output terminals of the second operational amplifier U2A. The inverting input terminal of the second operational amplifier U2A is connected to the other end of the third resistor R3, and the output terminal of the second operational amplifier U2A is connected to one end of the fourth resistor R4. The positive power supply of the second operational amplifier U2A is connected to the power supply, and the negative power supply of the second operational amplifier U2A is grounded.

8. The circuit according to claim 7, characterized in that, The second operational amplifier U2A is specifically a single-supply operational amplifier.

9. The circuit according to claim 3, characterized in that, The first filter unit includes: an eighth capacitor C8, a ninth capacitor C9, a tenth capacitor C10, a fifteenth resistor R15, a sixteenth resistor R16, and a third operational amplifier U3A; One end of the fifteenth resistor R15 is connected to one end of the eighth capacitor C8, and the common end of the connection is connected to the other end of the fourth resistor R4 and one end of the ninth capacitor C9. The other end of the ninth capacitor C9 is connected to the inverting input of the third operational amplifier U3A, and the common terminal of the connection is connected to one end of the sixteenth resistor R16 and one end of the tenth capacitor C10. The other end of the eighth capacitor C8 is connected to the output terminal of the third operational amplifier U3A, and the common terminal of their connection is connected to the other end of the sixteenth resistor R16 and the other end of the tenth capacitor C10. The output terminal of the third operational amplifier U3A is connected to one end of the fifth resistor R5.

10. The circuit according to claim 3, characterized in that, The second filter unit includes: an eleventh capacitor C11, a twelfth capacitor C12, a thirteenth capacitor C13, a seventeenth resistor R17, an eighteenth resistor R18, and a fourth operational amplifier U4A; One end of the seventeenth resistor R17 is connected to one end of the eleventh capacitor C11, and the common terminal of their connection is connected to the other end of the fifth resistor R5 and one end of the twelfth capacitor C12. The other end of the twelfth capacitor C12 is connected to the inverting input of the fourth operational amplifier U4A, and the common terminal of the connection is connected to one end of the eighteenth resistor R18 and one end of the thirteenth capacitor C13. The positive power supply of the fourth operational amplifier U4A is connected to the power supply, and the negative power supply of the fourth operational amplifier U4A is grounded. The other end of the eleventh capacitor C11 is connected to the output terminal of the fourth operational amplifier U4A, and the common terminal of the connection is connected to the other end of the eighteenth resistor R18 and the other end of the thirteenth capacitor C13. The output terminal of the fourth operational amplifier U4A is connected to one end of the sixth resistor R6.

11. The circuit according to claim 1, characterized in that, The diode envelope detection unit includes: a fifth diode Q5, a sixth diode Q6, a fourteenth capacitor C14, a nineteenth resistor R19, and a twentieth resistor R20. The negative terminal of the fifth diode Q5 is connected to the positive terminal of the sixth diode Q6, and their common terminal is connected to the other end of the sixth resistor R6. The positive terminal of the fifth diode Q5 is connected to one end of the nineteenth resistor R19, and its common terminal is connected to one end of the fourteenth capacitor C14 and grounded. The negative terminal of the sixth diode Q6 is connected to one end of the twentieth resistor R20, and the common terminal of the connection is connected to the other end of the fourteenth capacitor C14 and the other end of the nineteenth resistor R19.

12. An ultrasonic ranging method integrating ultrasonic transceiver, characterized in that, An ultrasonic ranging circuit applied to the ultrasonic transceiver integrated circuit according to any one of claims 1 to 11 includes: The driving unit transmits ultrasonic signals by driving the ultrasonic transceiver unit. When the ultrasonic signal encounters an obstacle, the echo signal is received by the ultrasonic transceiver unit. The echo signal is amplified by the amplification unit. The amplified echo signal is filtered by the filtering unit. The filtered echo signal is sent to the microcontroller unit via the diode envelope detector, so that the microcontroller unit can perform distance measurement based on the filtered echo signal.

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