CN107390203A - A kind of ultrasonic ranging method, apparatus and system - Google Patents

Abstract

The embodiments of the invention provide a kind of ultrasonic ranging method, device and system.This method includes：Launch ultrasonic wave to determinand, and record the first current moment；Receives echo-signal；Prime amplification and sampling are carried out to the echo-signal of reception within the default blind area time；By the signal intensity of the echo-signal sampled every time compared with the first signal strength threshold；First signal strength threshold is more than amplitude of the signal intensity of interference signal under prime multiplication factor, and is less than amplitude of minimum signal strength of the blind area apart from interior useful signal under prime multiplication factor；Within the default blind area time, if the signal intensity of echo-signal of sampling is more than the first signal strength threshold, record the second current moment, the time interval at the second moment and the first moment for ultrasonic propagation total duration；The distance value of determinand is obtained according to ultrasonic propagation velocity and total duration.As can be seen that the distance-finding method can detect to the distance value of the determinand in existing blind area.

Description

A kind of ultrasonic ranging method, apparatus and system

Technical field

The present invention relates to ultrasonic technology field, more particularly to a kind of ultrasonic ranging method, device and is System.

Background technology

Existing ultrasonic ranging system is commonly divided into two classes, i.e., transmitting-receiving integrated system and transmitting-receiving are split type System.For transmitting-receiving integrated system, the system only has a ultrasonic sensor, the sensor Play a part of launching and receiving ultrasonic wave simultaneously, when launching ultrasonic wave, the system can apply the arteries and veins of high intensity Signal is rushed on ultrasonic sensor, if transmitting makes the system be transferred to reception state immediately to detect back after terminating Ripple signal, the then remained shock that sensor can be retained on its own are disturbed, and can not detect echo-signal exactly In useful signal (i.e. by the ultrasonic wave that the ultrasonic sensor is sent in itself by determinand reflection Afterwards, finally by the part signal received by the ultrasonic sensor, the i.e. echo of ultrasonic wave in itself, and Do not include interference signal part), therefore typically need just to carry out after after a period of time, treating remained shock signal de-emphasis The detection of echo-signal.For receiving and dispatching split type system, the system has two ultrasonic sensors, One is used for launching ultrasonic wave, and one is used for receiving ultrasonic wave, and the problem of remained shock is disturbed is not present in the system, But the ultrasonic wave launched by emission sensor might have a part and directly be received by reception sensor, be Avoid receiving sensor and directly receive ultrasonic signal, usually after ultrasonic wave sends a period of time Carry out the detection of echo-signal.

Both the above system is likely to be received certain interference signal, whether in transmitting-receiving integrated system Reception is acted directly in interference signal caused by remained shock, or the split type system of transmitting-receiving by transmission sensor to pass Interference signal on sensor, therefore in order to avoid interference signal impacts to measurement result, sent in ultrasonic wave In the one shorter time (i.e. blind area time, the value can be obtained by test of many times) afterwards without The detection of echo-signal, correspondingly, if the distance value of determinand is smaller, i.e., when determinand is placed exactly in blind area Between within the distance range (blind area distance) that can measure, then the useful signal of determinand feedback will be unable to by Sensor receives, not to mention calculates the distance value of determinand accordingly.

As can be seen that for prior art, the distance value of the determinand in the distance of blind area can not obtain To detection.

The content of the invention

The purpose of the embodiment of the present invention is to provide a kind of ultrasonic ranging method, apparatus and system, for pair The distance of determinand in the distance of blind area is detected.

On the one hand, the embodiments of the invention provide a kind of ultrasonic ranging method, this method to comprise the following steps：

Control ultrasonic sensor to launch ultrasonic wave to determinand, and record the first current moment；

Control ultrasonic sensor receives echo-signal；

Within the default blind area time, prime amplification and sampling are carried out in real time to the echo-signal of reception；

By the signal intensity of the echo-signal sampled every time and the first signal intensity threshold in advance measuring and store Value is compared；First signal strength threshold is more than the signal intensity of the interference signal measured in advance preceding Amplitude under level multiplication factor, and it is strong less than the minimum signal of the useful signal in the blind area distance measured in advance Spend the amplitude under prime multiplication factor；

Within the default blind area time, if the signal intensity of the echo-signal of sampling is more than the first signal intensity threshold Value, it is determined that detect useful signal, and record the second current moment, second moment and described the Time interval between one moment is the total duration of ultrasonic propagation；According to the speed of ultrasonic propagation and described Total duration obtains the distance value of the determinand.

Further, the above method also includes：

If being not detected by useful signal within the default blind area time, when reaching the default blind area time, Rear class amplification and sampling are carried out in real time to the echo-signal of reception；Wherein, rear class multiplication factor is more than prime Multiplication factor；By the signal intensity of the echo-signal sampled every time and the second letter in advance measuring and store Number intensity threshold is compared；The secondary signal intensity threshold is that the blind area distance measured in advance is outer, ultrasonic Amplitude of the minimum signal strength of useful signal under rear class multiplication factor in the maximum range of wave sensor；

If the signal intensity of the echo-signal of sampling is more than secondary signal intensity threshold, it is determined that detects Useful signal, and record the 3rd current moment, the time between the 3rd moment and first moment At intervals of the total duration of ultrasonic propagation；Treated according to obtaining the speed of ultrasonic propagation and the total duration Survey the distance value of thing；

Wherein, the detection time of the rear class amplification is equal to the ultrasonic sensor plus the blind area time Maximum range corresponding to the very first time.

Further, the above method also includes：

If being not detected by useful signal in the very first time corresponding to the maximum range in ultrasonic sensor, When reaching the very first time, the distance value for setting the determinand is maximum range value, and controls the ultrasound Wave sensor launches ultrasonic wave to determinand again, re-starts detection.

Further, in the above method, default rear class number of stages of amplification is N, and N is the natural number not less than 2, The above method also includes：

If being not detected by useful signal within the default blind area time, step is performed：

A1, when reaching the default blind area time, first order rear class is carried out in real time to the echo-signal of reception Amplification and sampling；

A2, by the signal intensity of the echo-signal sampled every time and the 3rd signal that in advance measures and store Intensity threshold is compared；3rd signal strength threshold is the blind area measured in advance apart from the outer, first order Amplitude of the minimum signal strength of useful signal under first order rear class multiplication factor in rear class detecting distance；

A3, within the default first order rear class amplification detection time, if sampling the echo-signal signal Intensity is more than the 3rd signal strength threshold, it is determined that and useful signal is detected, and records the 4th current moment, Time interval between 4th moment and first moment is the total duration of ultrasonic propagation；According to super The speed of Acoustic Wave Propagation and the total duration obtain the distance value of the determinand；

If when reaching the default first order rear class amplification detection time, useful signal is not detected by, then

B1, the echo-signal to reception carry out the amplification of next stage rear class and sampling in real time；

B2, the signal intensity of the echo-signal sampled every time believed with the l+2 in advance measuring and storing Number intensity threshold is compared, wherein, l is current rear class number of stages of amplification, the l+2 signal intensity thresholds Outside the blind area distance for being worth to measure in advance, the minimum signal strength of useful signal exists in l level rear class detecting distances Amplitude under next stage multiplication factor, wherein, l is the natural number not less than 2 and no more than N；

B3, within the default next stage rear class amplification detection time, if sampling the echo-signal signal Intensity is more than l+2 signal strength thresholds, it is determined that when detecting useful signal, and recording current l+3 Carve, the time interval between the l+3 moment and first moment is the total duration of ultrasonic propagation； The distance value of the determinand is obtained according to the speed of ultrasonic propagation and the total duration；

If B4, when reaching the default next stage rear class amplification detection time, useful signal is not detected by, then Perform step：

C1, judge whether current rear class number of stages of amplification is N, if so, then setting the distance of the determinand It is worth for maximum range value, and controls the ultrasonic sensor to launch ultrasonic wave to determinand again, enters again Row detection；Otherwise, return and perform the step B1；

Wherein, the summation of the default N levels rear class amplification detection time was equal to along with the blind area time The very first time corresponding to the maximum range of the ultrasonic sensor, also, in N level rear class amplification process, Multiplication factor at different levels is all higher than the multiplication factor of previous stage.

Further, the above method also includes：

Measure and be stored under different detection total times in advance, the echo-signal arrival moment reaches with echo-signal Time interval between at the time of each signal strength threshold, the time interval are the compensation time；

Obtain the total duration and the duration difference of the compensation time；

The distance value that determinand is obtained according to ultrasonic propagation velocity and total duration, it is：According to ultrasonic wave Spread speed and the duration difference obtain the distance value of the determinand.

Further, the above method also includes：

Obtain the environment temperature residing for the ultrasonic wave；

The actual propagation speed of the ultrasonic wave is obtained according to the environment temperature；

The distance value that determinand is obtained according to ultrasonic propagation velocity and total duration, it is：According to described super The actual propagation speed of sound wave and the total duration obtain the distance value of the determinand.

On the other hand, the embodiment of the present invention additionally provides a kind of supersonic range finder, and the device includes：

Transmitter module, for controlling ultrasonic sensor to launch ultrasonic wave to determinand, and record current the One moment；

Receiving module, for controlling ultrasonic sensor receives echo-signal；

First processing module, within the default blind area time, being carried out in real time to the echo-signal of reception Prime is amplified and sampling；

First comparison module, for by the signal intensity of the echo-signal sampled every time with measuring and storing in advance The first signal strength threshold be compared；First signal strength threshold is more than the interference letter measured in advance Number amplitude of the signal intensity under prime multiplication factor, and less than effective in the blind area distance measured in advance Amplitude of the minimum signal strength of signal under prime multiplication factor；

First computing module, within the default blind area time, if the signal intensity of the echo-signal of sampling More than the first signal strength threshold, it is determined that detect useful signal, and record the second current moment, institute State the total duration that the time interval between the second moment and first moment is ultrasonic propagation；According to ultrasound Speed and the total duration that ripple is propagated obtain the distance value of the determinand.

Further, said apparatus also includes：

Second processing module, if for being not detected by useful signal within the default blind area time, default The blind area time reach when, rear class amplification and sampling are carried out in real time to the echo-signal of reception, wherein, after Level multiplication factor is more than prime multiplication factor；

Second comparison module, for the signal intensity of the echo-signal sampled every time to be measured simultaneously with advance The secondary signal intensity threshold of storage is compared；The secondary signal intensity threshold is the blind area measured in advance The minimum signal strength of useful signal is in rear class multiplication factor in outer, ultrasonic sensor maximum range Under amplitude；

Second computing module, if the signal intensity of the echo-signal for sampling is more than secondary signal intensity Threshold value, it is determined that detect useful signal, and record the 3rd current moment, the 3rd moment with it is described Time interval between first moment is the total duration of ultrasonic propagation；According to the speed of ultrasonic propagation and institute State the distance value that total duration obtains the determinand；

Wherein, the detection time of the rear class amplification is equal to the ultrasonic sensor plus the blind area time Maximum range corresponding to the very first time.

Further, said apparatus also includes：

First judge module, if in the very first time corresponding to the maximum range in ultrasonic sensor not Useful signal is detected, then when reaching the very first time, the distance value for setting the determinand is maximum range Value, and control the ultrasonic sensor to launch ultrasonic wave to determinand again, re-start detection.

Further, in said apparatus, default rear class number of stages of amplification is N, and N is the natural number not less than 2, Said apparatus also includes：

3rd processing module, if for being not detected by useful signal within the default blind area time, default The blind area time reach when, the amplification of first order rear class and sampling are carried out in real time to the echo-signal of reception；

3rd comparison module, for the signal intensity of the echo-signal sampled every time to be measured simultaneously with advance 3rd signal strength threshold of storage is compared；3rd signal strength threshold is the blind area measured in advance The minimum signal strength of useful signal is in first order rear class times magnification in outer, first order rear class detecting distance Amplitude under several；

3rd computing module, within the default first order rear class amplification detection time, if sampling is described The signal intensity of echo-signal is more than the 3rd signal strength threshold, it is determined that detects useful signal, and records The 4th current moment, the time interval between the 4th moment and first moment is ultrasonic propagation Total duration；The distance value of the determinand is obtained according to the speed of ultrasonic propagation and the total duration；

Fourth processing module, if for when reaching the default first order rear class amplification detection time, not detecting To useful signal, then the amplification of next stage rear class and sampling are carried out in real time to the echo-signal of reception；

4th comparison module, for the signal intensity of the echo-signal sampled every time to be measured simultaneously with advance The l+2 signal strength thresholds of storage are compared, wherein, l is current rear class number of stages of amplification, described the L+2 signal strength thresholds are the blind area measured in advance useful signal in outer, l level rear class detecting distances Amplitude of the minimum signal strength under next stage multiplication factor, wherein, l is not less than 2 and no more than N's Natural number；

4th computing module, within the default next stage rear class amplification detection time, if sampling is described The signal intensity of echo-signal is more than l+2 signal strength thresholds, it is determined that detects useful signal, and remembers At the record current l+3 moment, the time interval between the l+3 moment and first moment is ultrasonic wave The total duration of propagation；The distance of the determinand is obtained according to the speed of ultrasonic propagation and the total duration Value；

Second judge module, if for when reaching the default next stage rear class amplification detection time, not detecting To useful signal, then judge whether current rear class number of stages of amplification is N, if so, then set determinand away from It is maximum range value from value, and controls ultrasonic sensor to launch ultrasonic wave to determinand again, re-starts Detection；Otherwise, the amplification of more next stage rear class and sampling are carried out in real time to the echo-signal of reception；

Wherein, the summation of the default N levels rear class amplification detection time was equal to along with the blind area time The very first time corresponding to the maximum range of the ultrasonic sensor, also, in N level rear class amplification process, Multiplication factor at different levels is all higher than the multiplication factor of previous stage.

Further, said apparatus also includes：

Measurement module, for measuring and being stored in advance under different detection total times, when echo-signal arrives Carve and at the time of echo-signal reaches each signal strength threshold between time interval, the time interval is compensation Time；

First acquisition module, for obtaining the total duration and the duration difference of the compensation time；

5th computing module, obtained for the spread speed according to ultrasonic wave and the duration difference described to be measured The distance value of thing.

Further, said apparatus also includes：

Second acquisition module, for obtaining the environment temperature residing for the ultrasonic wave；

Second acquisition module, for obtaining the actual propagation speed of the ultrasonic wave according to the environment temperature；

6th computing module, institute is obtained for the actual propagation speed according to the ultrasonic wave and the total duration State the distance value of determinand.

Another further aspect, the embodiment of the present invention additionally provide a kind of ultrasonic ranging system, and the system includes：It is super Sonic sensor and the controller for being connected to the ultrasonic sensor；Wherein,

The ultrasonic sensor is used to launch ultrasonic wave and receives echo-signal；

The controller was used within the default blind area time, before being carried out in real time to the echo-signal received Level amplification and sampling, and by the signal intensity of the echo-signal sampled every time with advance measure and store first Signal strength threshold is compared；First signal strength threshold is more than the interference signal measured in advance Amplitude of the signal intensity under prime multiplication factor, and less than the minimum signal of the useful signal measured in advance Amplitude of the intensity under prime multiplication factor；Within the default blind area time, if the letter of the echo-signal of sampling Number intensity is more than the first signal strength threshold, it is determined that useful signal is detected, according to detecting useful signal At the time of and ultrasonic wave at the time of launch between time interval obtain the total duration of ultrasonic propagation, and according to The speed and total duration of ultrasonic propagation obtain the distance value of the determinand.

Further, in said system, the ultrasonic sensor is transmitting-receiving integrated sensor or transmitting-receiving point Body formula sensor.

As seen from the above technical solutions, for this ultrasonic ranging method provided in an embodiment of the present invention, It for device and system, can first control ultrasonic sensor to launch ultrasonic wave to determinand, and record current The first moment, then control ultrasonic sensor receives echo-signal；Then within the default blind area time, The signal intensity of the echo-signal sampled every time is entered with the first signal strength threshold for measuring and storing in advance Row compares；First signal strength threshold is more than the signal intensity of the interference signal measured in advance in prime times magnification Amplitude under several, and the minimum signal strength of the useful signal less than the blind area measured in advance in is in prime Amplitude under multiplication factor；Within the default blind area time, if the signal intensity of the echo-signal of sampling is more than First signal strength threshold, it is determined that detect useful signal, and record the second current moment, when second The time interval at quarter and the first moment is the total duration of ultrasonic propagation；Finally according to the speed of ultrasonic propagation Degree and total duration obtain the distance value of determinand.As can be seen that the embodiment of the present invention is sent in ultrasonic wave After can immediately begin to receives echo-signal and echo-signal is detected, without waiting the blind area time Just started the detection of echo-signal after past, therefore the embodiment of the present invention can receive what is returned in the time of blind area Useful signal, and then the distance value for the determinand being pointed in the distance of blind area is detected.In addition, with it is existing Technology is compared, and the method for judging whether to have useful signal in the embodiment of the present invention is relatively simple, direct basis Whether the ADC under AWD mode of operations occurs whether to interrupt the arrival that may know that useful signal, no Need to carry out the steps such as rectification, envelope detected, differential, zero passage detection and peakvalue's checking successively, so as to significantly Ground simplifies the judgment step of useful signal, and then makes the ultrasonic ranging method more simple.

Brief description of the drawings

In order to illustrate more clearly about the embodiment of the present invention or technical scheme of the prior art, below will be to implementing The required accompanying drawing used is briefly described in example or description of the prior art, it should be apparent that, describe below In accompanying drawing be only some embodiments of the present invention, for those of ordinary skill in the art, do not paying On the premise of going out creative work, other accompanying drawings can also be obtained according to these accompanying drawings.

Fig. 1 is the flow chart of ultrasonic ranging method provided in an embodiment of the present invention；

Fig. 2 is the another flow chart of ultrasonic ranging method provided in an embodiment of the present invention；

Fig. 3 is the another flow chart of ultrasonic ranging method provided in an embodiment of the present invention；

Fig. 4 is the another flow chart of ultrasonic ranging method provided in an embodiment of the present invention；

Fig. 5 is the another flow chart of ultrasonic ranging method provided in an embodiment of the present invention；

Fig. 6 is the structured flowchart of supersonic range finder provided in an embodiment of the present invention；

Fig. 7 is the another structured flowchart of supersonic range finder provided in an embodiment of the present invention；

Fig. 8 is the another structured flowchart of supersonic range finder provided in an embodiment of the present invention；

Fig. 9 is the another structured flowchart of supersonic range finder provided in an embodiment of the present invention；

Figure 10 is the structural representation of ultrasonic ranging system provided in an embodiment of the present invention.

Embodiment

Below in conjunction with the accompanying drawing in the embodiment of the present invention, the technical scheme in the embodiment of the present invention is carried out clear Chu, it is fully described by, it is clear that described embodiment is only part of the embodiment of the present invention, rather than Whole embodiments.Based on the embodiment in the present invention, those of ordinary skill in the art are not making creation Property work under the premise of the every other embodiment that is obtained, belong to the scope of protection of the invention.

Ultrasonic ranging method embodiment：

Referring to Fig. 1, Fig. 1 is the flow chart of ultrasonic ranging method provided in an embodiment of the present invention.Such as Fig. 1 institutes Show, this method comprises the following steps：

When step S101, controlling ultrasonic sensor to launch ultrasonic wave to determinand, and recording current first Carve.

Wherein, ultrasonic sensor can be transmitting-receiving integrated sensor or the split type sensor of transmitting-receiving.This reality Apply in example, ultrasonic sensor can be connected with a controller, and the controller can include：Single-chip microcomputer and Timer.When it is implemented, the port of single-chip microcomputer can produce multiple, such as 8 opposite polarities simultaneously, Frequency is 40KHz square-wave signal, to act on ultrasonic sensor, makes the ultrasonic sensor to be measured Thing launches ultrasonic wave, while timer automatically turns on, and timer is recorded the first current moment.

Step S102, control ultrasonic sensor receives echo-signal.

Step S103, within the default blind area time, prime amplification is carried out in real time to the echo-signal of reception And sampling.

In the present embodiment, controller can also include amplifying circuit and ADC (Analog Digital Converter, analog-digital converter), wherein, amplifying circuit is used for carrying out prime amplification, ADC to echo-signal For sampling the echo-signal after prime is amplified to obtain sampled value.Due to entering within the default blind area time Row sampling, therefore echo-signal different may be formed by two kinds：When sampling time very in short-term, echo letter May only have interference signal in number；May only have when lengthening the time of sampling, in echo-signal effective Signal.Once echo-signal is amplified by prime, then useful signal or interference signal can be exaggerated, and prime is put Big multiple can determine according to actual conditions, only need to ensure that the interference signal after prime is amplified is undistorted i.e. Can, the present embodiment does not do any restriction to the specific multiplication factor that prime is amplified.

Step S104, by the signal intensity of the echo-signal sampled every time and the first letter in advance measuring and store Number intensity threshold is compared, and the first signal strength threshold is more than the signal intensity of the interference signal measured in advance Amplitude under prime multiplication factor, and it is less than the minimum signal strength of the useful signal measured in advance in prime Amplitude under multiplication factor.

It can be seen from test of many times, the amplitude of interference signal and duration (i.e. blind area time) are fixation Value, the two values can obtain by testing.Specifically, the blind area time can be 1.8ms.And for For useful signal in the distance of blind area, its minimum signal strength may be considered the boundary from blind area distance The signal intensity of the echo-signal of return, the value can also be obtained by testing, eventually through interference signal The minimum signal strength of amplitude and useful signal of the signal intensity under prime multiplication factor amplify in prime Amplitude under multiple, you can obtain the first signal strength threshold.When it is implemented, can be previously according to first The first sampling threshold is calculated in signal strength threshold, and the first sampled intensity threshold value then is pre-stored in into ADC It is interior, ADC is under AWD (Analog Watchdog, simulating house dog) mode of operation, this Sample ADC can be constantly by sampled value compared with the first sampling threshold.

Step S105, within the default blind area time, if the signal intensity of the echo-signal after sampling is more than the One signal strength threshold, it is determined that detect useful signal, and record the second current moment, the second moment Time interval between the first moment is the total duration of ultrasonic propagation；According to the speed of ultrasonic propagation and Total duration obtains the distance value of determinand.

By test of many times, within the time of blind area, the amplitude of useful signal can be much larger than interference signal Amplitude, correspondingly, the amplitude of the useful signal under same multiplication factor can also be much larger than the amplitude of interference signal. Again because the first signal strength threshold is in amplitude of the signal intensity of interference signal under prime multiplication factor Between the amplitude of the minimum signal strength of useful signal under prime multiplication factor, if therefore the letter of echo-signal Number intensity is more than the first signal strength threshold, then the signal intensity of the echo-signal sampled is naturally larger than prime and put The amplitude of interference signal under big multiple, therefore necessarily there is useful signal in echo-signal, at this moment record Second moment was at the time of receiving useful signal.When it is implemented, it is placed under AWD mode of operations ADC samples the echo-signal after prime is amplified with being continued for, and automatically by sampled value and the first sampling Threshold value is compared, if sampled value is more than the first sampling threshold, illustrates that the signal intensity of echo-signal is more than First signal strength threshold, that is, there is useful signal in the echo-signal sampled, during now ADC can be produced Disconnected, ADC will not continue to sampled echo signals, and timer can record the specific moment for producing and interrupting, i.e., Second moment.So, the difference between the second moment and the first moment recorded according to timer can obtain To the total duration t of ultrasonic propagation, the speed v of ultrasonic propagation can directly refer to its theoretical value, then to be measured The distance value L of thing can be calculated by formula L=v*t/2.

As can be seen that in the ultrasonic ranging method that the present embodiment provides, ultrasonic sensor can be in ultrasound Ripple gets started receives echo-signal and echo-signal is detected after sending, without wait blind area when Between in the past after just start to detect, therefore the present invention can receive the useful signal returned in the time of blind area, and most The distance value of the determinand in the distance of blind area is obtained according to the total duration of ultrasonic propagation and speed eventually.This Outside, compared with prior art, judge whether to have that the method for useful signal is relatively simple in the embodiment of the present invention, Directly know arriving for useful signal according to whether the ADC being under AWD mode of operations produces interruption can Whether come, it is not necessary to the steps such as rectification, envelope detected, differential, zero passage detection and peakvalue's checking are carried out successively, So as to significantly simplify the judgment step of useful signal, and then make the ultrasonic ranging method more simple.

In practical application, if being not detected by useful signal within the time of blind area, illustrate determinand positioned at blind Offset can be carried out from outer in real time when reaching the default blind area time to the echo-signal received Rear class is amplified and sampling, is detected with the distance value to the determinand outside the distance of blind area.Amplified according to rear class The difference of series, the ultrasonic ranging method can have two kinds of different embodiments.

In the first embodiment, the series of rear class amplification can be only one-level, now the ultrasonic ranging side The flow chart of method is referred to Fig. 2.As shown in Fig. 2 the present invention may include steps of：

When step S201, controlling ultrasonic sensor to launch ultrasonic wave to determinand, and recording current first Carve.

Step S202, control ultrasonic sensor receives echo-signal.

Step S203, within the default blind area time, prime amplification is carried out in real time to the echo-signal of reception And sampling.

Step S204, by the signal intensity of the echo-signal sampled every time and the first letter in advance measuring and store Number intensity threshold is compared, and the first signal strength threshold is more than the signal intensity of the interference signal measured in advance Amplitude under prime multiplication factor, and it is less than the minimum signal strength of the useful signal measured in advance in prime Amplitude under multiplication factor.

Step S205, within the default blind area time, if the signal intensity of the echo-signal after sampling is more than the One signal strength threshold, it is determined that detect useful signal, and record the second current moment, the second moment Time interval between the first moment is the total duration of ultrasonic propagation；According to the speed of ultrasonic propagation and Total duration obtains the distance value of determinand.

Wherein, step S201 to step S205 specific implementation process reference described above, herein no longer Repeat.

Step S206, if useful signal is not detected by within the default blind area time, at default blind area Between when reaching, rear class amplification and sampling are carried out in real time to the echo-signal of reception.

Wherein, rear class multiplication factor can be more than prime multiplication factor, and the specific value of rear class multiplication factor can To be determined according to actual conditions, the present embodiment does not do any restriction to this.Due to the determinand of rear class amplification Be respectively positioned on blind area distance outside, with blind area distance in determinand compared with, its distance value is larger, thus need with Bigger multiplication factor carries out the amplification of echo-signal, can so ensure the letter of amplified echo-signal Number intensity is larger, so as to ensure that useful signal can be clearly identified.

Step S207, by the signal intensity of the echo-signal sampled every time and the second letter in advance measuring and store Number intensity threshold is compared；Secondary signal intensity threshold is that the blind area measured in advance passes apart from outer, ultrasonic wave Amplitude of the minimum signal strength of useful signal under rear class multiplication factor in the maximum range of sensor.

Wherein, the minimum signal strength of blind area useful signal in outer, ultrasonic sensor maximum range Can be the intensity of the echo-signal returned by the maximum range of ultrasonic sensor, its value can also pass through Test of many times obtains, and so, secondary signal intensity threshold is can obtain according to the value.When it is implemented, can It is then that the second sampling threshold is pre- so that the second sampling threshold is calculated previously according to secondary signal intensity threshold It is stored in ADC, ADC is under AWD mode of operations, such ADC can be constantly by sampled value Compared with the second sampling threshold.

Step S208, if the signal intensity of the echo-signal of sampling is more than secondary signal intensity threshold, it is determined that Useful signal is detected, and records the 3rd current moment, between the time between the 3rd moment and the first moment It is divided into the total duration of ultrasonic propagation；The distance of determinand is obtained according to the speed of ultrasonic propagation and total duration Value.

Wherein, the detection time of rear class amplification is equal to the maximum range institute of ultrasonic sensor plus the blind area time The corresponding very first time.So, this method can be pointed to all determinands in the maximum range of ultrasonic wave Distance value detected.

If when it is implemented, when being not detected by useful signal within the default blind area time, AWD works are placed in ADC under operation mode can constantly sample the echo-signal after rear class is amplified, and automatically by sampled value with Second sampling threshold is compared, if sampled value is more than the second sampling threshold, illustrates the signal of echo-signal Intensity is more than secondary signal intensity threshold, that is, has useful signal in the echo-signal sampled, now ADC Interruption is produced, ADC will not continue to sampled echo signals, at the time of timer can record generation interruption, That is the 3rd moment.So, difference between the 3rd moment and the first moment recorded according to timer and The speed of ultrasonic propagation is that can obtain the distance value of determinand.

As can be seen that the present embodiment can also be pointed to outside the distance of blind area, the maximum range of ultrasonic sensor The distance value of interior determinand measures, also, its judge whether to receive the operation of useful signal also compared with To be simple, directly know effectively according to whether the ADC being under AWD mode of operations produces interruption can Whether signal arrives, so that the ultrasonic ranging method is more simple.

In the first embodiment, the flow chart of ultrasonic ranging method can be with reference picture 3.As shown in figure 3, The present invention may include steps of：

Step 3201, when controlling ultrasonic sensor to launch ultrasonic wave to determinand, and recording current first Carve.

Step S302, control ultrasonic sensor receives echo-signal.

Step S303, within the default blind area time, prime amplification is carried out in real time to the echo-signal of reception And sampling.

Step S304, by the signal intensity of the echo-signal sampled every time and the first letter in advance measuring and store Number intensity threshold is compared, and the first signal strength threshold is more than the signal intensity of the interference signal measured in advance Amplitude under prime multiplication factor, and it is less than the minimum signal strength of the useful signal measured in advance in prime Amplitude under multiplication factor.

Step S305, within the default blind area time, if the signal intensity of the echo-signal after sampling is more than the One signal strength threshold, it is determined that detect useful signal, and record the second current moment, the second moment Time interval between the first moment is the total duration of ultrasonic propagation；According to the speed of ultrasonic propagation and Total duration obtains the distance value of determinand.

Step S306, if useful signal is not detected by within the default blind area time, at default blind area Between when reaching, rear class amplification and sampling are carried out in real time to the echo-signal of reception.

Step S307, by the signal intensity of the echo-signal sampled every time and the second letter in advance measuring and store Number intensity threshold is compared；Secondary signal intensity threshold is that the blind area measured in advance passes apart from outer, ultrasonic wave Amplitude of the minimum signal strength of useful signal under rear class multiplication factor in the maximum range of sensor.

Step S308, if the signal intensity of the echo-signal of sampling is more than secondary signal intensity threshold, it is determined that Useful signal is detected, and records the 3rd current moment, between the time between the 3rd moment and the first moment It is divided into the total duration of ultrasonic propagation；The distance of determinand is obtained according to the speed of ultrasonic propagation and total duration Value.

Wherein, step S301 to step S308 embodiment is with reference to described above, the present embodiment It will not be repeated here.

Step S309, if being not detected by very first time corresponding to maximum range in ultrasonic sensor Signal is imitated, then when reaching the very first time, the distance value for setting determinand is maximum range value, and is controlled super Sonic sensor launches ultrasonic wave to determinand again, re-starts detection.

In the present embodiment, the process of rear class amplification can not possibly go on without end, if in the very first time not Useful signal is detected, then illustrates that determinand is located at outside the measuring range of ultrasonic sensor, now can be with Ultrasonic sensor is set to launch ultrasonic wave to determinand again, to carry out next round detection process.

In second of embodiment, the series of rear class amplification can be N levels, and N is the natural number not less than 2, Now the flow chart of the ultrasonic ranging method is referred to Fig. 4.As shown in figure 4, the present invention can be included such as Lower step：

When step S401, controlling ultrasonic sensor to launch ultrasonic wave to determinand, and recording current first Carve.

Step S402, control ultrasonic sensor receives echo-signal.

Step S403, within the default blind area time, prime amplification is carried out in real time to the echo-signal of reception And sampling.

Step S404, by the signal intensity of the echo-signal sampled every time and the first letter in advance measuring and store Number intensity threshold is compared, and the first signal strength threshold is more than the signal intensity of the interference signal measured in advance Amplitude under prime multiplication factor, and it is less than the minimum signal strength of the useful signal measured in advance in prime Amplitude under multiplication factor.

Step S405, within the default blind area time, if the signal intensity of the echo-signal after sampling is more than the One signal strength threshold, it is determined that detect useful signal, and record the second current moment, the second moment Time interval between the first moment is the total duration of ultrasonic propagation；According to the speed of ultrasonic propagation and Total duration obtains the distance value of determinand.

Wherein, step S401 to S405 specific implementation process will not be repeated here with reference to described above.

Step S406, if useful signal is not detected by within the default blind area time, at default blind area Between when reaching, the amplification of first order rear class and sampling are carried out in real time to the echo-signal of reception.

Wherein, first order rear class multiplication factor can be more than prime multiplication factor, first order rear class multiplication factor Specific value can determine that the present embodiment does not do any restriction to this, through the first order according to actual conditions The sampling process of echo-signal after rear class amplification can also be completed by ADC.

Step S407, by the signal intensity of the echo-signal sampled every time and the 3rd letter that in advance measures and store Number intensity threshold is compared；3rd signal strength threshold is that the blind area distance measured in advance is outer, after the first order Amplitude of the minimum signal strength of useful signal under first order rear class multiplication factor in level detecting distance.

Wherein, the 3rd signal strength threshold can also be obtained by test of many times.

Step S408, within the default first order rear class amplification detection time, if the letter of the echo-signal of sampling Number intensity is more than the 3rd signal strength threshold, it is determined that when detecting useful signal, and recording current the 4th Carve, the time interval between the 4th moment and the first moment is the total duration of ultrasonic propagation；According to ultrasonic wave The speed and total duration of propagation obtain the distance value of determinand.

Step S409, if when reaching the default first order rear class amplification detection time, it is not detected by effective letter Number, then the amplification of next stage rear class and sampling are carried out in real time to the echo-signal of reception.

Step S410, by the signal intensity of the echo-signal sampled every time and the l+2 that in advance measures and store Signal strength threshold is compared, wherein, l is current rear class number of stages of amplification；L+2 signal strength thresholds For the blind area distance that measures in advance is outer, in l level rear class detecting distances useful signal minimum signal strength under Amplitude under one-level multiplication factor, wherein, l is the natural number not less than 2 and no more than N.

Wherein, l+2 signal strength thresholds can also be obtained by test of many times.

Step S411, within the default next stage rear class amplification detection time, if the letter of the echo-signal of sampling Number intensity is more than l+2 signal strength thresholds, it is determined that detects useful signal, and records current l+3 Moment, the time interval between l+3 moment and the first moment are the total duration of ultrasonic propagation；According to super The speed and total duration of Acoustic Wave Propagation obtain the distance value of determinand.

Step S412, if when reaching the default next stage rear class amplification detection time, it is not detected by effective letter Number, then judge whether current rear class number of stages of amplification is N, if so, then setting the distance value of determinand as most Wide range value, and control ultrasonic sensor to launch ultrasonic wave to determinand again, re-start detection；It is no Then, return and perform step S409.

In the present embodiment, a pair of the detecting distance 1 of any level rear class amplification detection time and this grade of rear class amplification Should.Specifically, the one-level rear class amplification detection time can be pointed to be measured in one-level rear class detecting distance The distance value of thing is detected, the two level rear class amplification detection time can be pointed to two level rear class amplification detection away from Distance value from interior determinand is detected, the like.When it is implemented, rear class amplification detections at different levels Time can determine according to actual conditions, only need to ensure the total of default N levels rear class amplification detection time With along with the blind area time be equal to ultrasonic sensor maximum range corresponding to the very first time.Wherein, One time can also be obtained by test of many times.So, this method can be pointed to ultrasonic sensor most The distance value of all determinands in wide range is detected.

In the present embodiment, in N level rear class amplification process, multiplication factor at different levels is all higher than the amplification of previous stage Multiple.Specifically, first order rear class multiplication factor is more than prime multiplication factor, second level rear class times magnification Number is more than first order rear class multiplication factor, and third level rear class multiplication factor is more than second level rear class multiplication factor, The like.When it is implemented, the detection time per one-level rear class amplification process has been prestored in controller, Maximum duration i.e. corresponding to the rear class amplification process.Amplifying circuit can be believed echo with different multiplication factors Number it is amplified.The N levels rear class amplification detailed process be：First order rear class is carried out to echo-signal first Amplification, the signal that now ADC is sampled is the echo-signal after the amplification of first order rear class, if in the first order In the maximum duration of rear class amplification, ADC produces the letter of interruption, i.e. echo-signal after the amplification of first order rear class Number intensity is more than the 3rd signal strength threshold, then representing in the echo-signal that ADC is sampled has effectively letter Number, it was the 4th moment that ADC, which is produced at the time of interruption, then according to the difference at the 4th moment and the first moment Value and the spread speed of ultrasonic wave can calculate the distance value of determinand.If ADC amplifies in first order rear class Interruption is not produced in maximum duration, that is, represents ADC and is not detected by useful signal, now echo-signal is entered The rear class amplification of the row second level, therefore the signal that ADC is sampled is the echo-signal after the amplification of second level rear class. It is similar with the process of first order rear class amplification, interrupted when ADC is produced, then represent ADC and detect effective letter Number, if ADC does not produce interruption in the maximum duration that second level rear class is amplified yet, that is, represent second level rear class Amplification process is also not detected by useful signal, now may determine that whether current rear class number of stages of amplification is N, Judge whether second level rear class amplification is default afterbody rear class amplification, if so, then illustrating determinand Outside maximum range in ultrasonic sensor, ultrasonic sensor can be now controlled to be sent out again to determinand Ultrasonic wave is penetrated, to carry out next round detection process；If second level rear class amplification process is not default last One-level rear class is amplified, then can carry out third level rear class amplification to echo-signal, that is to say, that as long as a certain Level rear class amplification is not detected by useful signal in the maximum duration of this grade amplification, and this grade amplification is not pre- If afterbody amplification process, you can the detection process of next stage is transferred to, with another bigger multiplication factor Echo-signal is amplified, follow-up each rear class detection process is amplified with first order rear class and second level rear class The detection process of amplification is similar, and its specific Cleaning Principle will not be repeated here with reference to described above.

In the present embodiment, the process of N levels rear class amplification is particularly suitable for use in the larger situation of distance value of determinand. Specifically, echo-signal is after the amplification of certain one-level rear class, if being not detected by useful signal in echo-signal, It is probably because the distance value of determinand is larger, and the rear class multiplication factor of this grade is smaller, therefore echo-signal Signal intensity is weaker, so as to cause sensor can not collect obvious useful signal, at this moment will can gather The echo-signal arrived carries out next stage rear class amplification, after being more than previous stage due to the rear class multiplication factor of next stage Level multiplication factor, therefore signal intensity of the echo-signal under next stage rear class multiplication factor will be more than it is previous Signal intensity under level multiplication factor, if now can not still detect useful signal, can be put with bigger Big multiple is amplified to echo-signal, and the signal of such echo-signal will be bigger, and useful signal will more have It may be clearly identified.

At the time of ADC is produced interruption by above-described embodiment, i.e., the signal intensity of echo-signal exceedes a certain threshold As at the time of receiving useful signal at the time of value, and due to the oscillogram undulate of echo-signal, and And echo-signal also needs to be amplified and sample upon receipt, thus ADC produce interruption at the time of with There may be certain deviation between at the time of being an actually-received useful signal, therefore need to original ultrasound The total duration that ripple is propagated is compensated, and the distance value of such determinand can be corrected.

Specifically, the method compensated to the total duration of ultrasonic propagation includes：

Measure and be stored under different detection total times in advance, the echo-signal arrival moment reaches with echo-signal Time interval between at the time of each signal strength threshold, the time interval are the compensation time；

The measuring process of time is repaid with visible subsidy for a specific example below.

Assuming that the range of ultrasonic sensor is 5m, range 5m is equally divided into 100 parts, then per a reality Border distance value is 5cm, then since distance is at 5cm, detects an ADC every 5cm and produces what is interrupted The difference t at moment and the first moment, and according to the distance value L of difference t calculating determinands, through the calculating process Obtained distance value L is theoretical value, and the actual value L of distance value₁For what is predefined, its value is Know, so can be obtained by L and L₁Difference L₂, finally according to formula t₂=L₂/ v can obtain different inspections Survey the compensation time t corresponding to total time t₂。

Total duration is obtained with compensating the duration difference of time.

The distance value of determinand is obtained according to ultrasonic propagation velocity and total duration, is：According to ultrasonic propagation Speed and duration difference obtain the distance value of determinand.

As can be seen that the present embodiment can compensate to the total duration of ultrasonic propagation, so finally give Distance value will be more accurate.

In above-described embodiment, the spread speed of ultrasonic wave can be the theoretical spread speed of ultrasonic wave, still, May be with due to the influence of environment temperature, between the actual propagation speed of ultrasonic wave and its theoretical spread speed There is a certain degree of deviation, there is certain with actual distance value so as to cause the distance value of determinand that measures Deviation, therefore also need to be corrected the spread speed of ultrasonic wave, the distance value of such determinand can also obtain To correction.

Specifically, the method being corrected to the spread speed of ultrasonic wave comprises the following steps：

Obtain the environment temperature residing for ultrasonic wave.

Wherein, environment temperature can be measured in real time by temperature sensor.

The actual propagation speed of ultrasonic wave is obtained according to environment temperature.Wherein, environment temperature can be with T come table Show, the actual propagation speed of ultrasonic wave can use v₁To represent, v₁Conversion relation with T is：V₁(m/s) =331.5+0.607T.

The distance value of determinand is obtained according to ultrasonic propagation velocity and total duration, is：According to the reality of ultrasonic wave Border spread speed and total duration obtain the distance value of determinand.

As can be seen that the present embodiment take into account influence of the environment temperature to ultrasonic propagation velocity, and it is not straight Selecting theoretical spread speed of ultrasonic wave known to is the spread speed of ultrasonic wave, therefore avoids due to environment The change of temperature and measurement result is impacted so that the distance value finally given is more accurate.

With reference to Fig. 5, the situation that one-level is enlarged into rear class is carried out to the specific implementation process of the present embodiment Explanation.

As shown in figure 5, when it is implemented, progress step S501 first, completes ultrasonic wave transmitting.Then Perform step S502, i.e. TIMER1 counter resets.Specifically, calculator, which resets, launches ultrasonic wave Zero moment is designated as at the time of completion.Then step S503 is carried out, opens ADC sampling channels 1.Specifically, ADC opens sampling channel 1, and at this moment amplifying circuit carries out prime amplification, prime to the echo-signal collected The multiplication factor of amplification can be 23 times, while ADC samples to the echo-signal after amplification.Then hold Row step S504, judge whether that the AWD that ADC occurs is interrupted, if ADC occurs under AWD mode of operations Interrupt, that is, the signal intensity for representing echo-signal is more than the first signal strength threshold preset, therefore ADC is examined Useful signal has been measured, now by step S510, the TIMER1 count values recorded in being interrupted, TIMER1 count values are the total duration of ultrasonic propagation.Then according to step S511, using time bias, Obtain accurate transmission time.Wherein, the method reference described above of time bias, herein no longer Repeat.Step S512, Current Temperatures are obtained, and calculate the velocity of sound, the propagation speed that the step can be to ultrasonic wave Degree is corrected, and specific bearing calibration will not be repeated here with reference to described above.Then step is performed S513, according to the half for the product that distance value is TIMER1 count values and the velocity of sound, calculate distance value.Finally Perform step S515, that is, after treating that distance value calculates, open ultrasonic wave transmitting, re-emit ultrasonic wave with Carry out next round detection.

If ADC is not interrupted under AWD mode of operations in step S504,：Step S505 is first carried out, Whether judge TIMER1 values more than prime detection time-out time, i.e., the blind area time measured in advance, if so, Then represent and useful signal is not detected by the time of blind area, now perform step S506.Step S506 is unlatching ADC sampling channels 2.Specifically, when ADC opens sampling channel 2, amplifying circuit is believed the echo collected Number rear class amplification is carried out, rear class multiplication factor can be 34 times, while ADC enters to the echo-signal after amplification Row sampling.Then step S507 is carried out, judges whether that ADC, which occurs, to interrupt.If so, represent ADC detections Useful signal has been arrived, has now performed step S514, the TIMER1 count values recorded in being interrupted, the meter Numerical value is at the time of receiving useful signal, finally to carry out step S511, step S512, step S513 successively With step S515.

If judging that ADC is not interrupted in step S507, step S508 is performed, judges that TIMER1 is current Value whether be more than rear class detection time-out time, i.e., corresponding to the maximum range of ultrasonic sensor first when Between., now can be with if so, then represent measurement range of the distance value beyond ultrasonic sensor of determinand The distance value for showing the ultrasonic sensor is maximum range, step S515 is then performed, to open ultrasound Ripple is launched, and re-starts next round detection.

To sum up, the ultrasonic ranging method that the present embodiment provides can be pointed to the determinand in the distance of blind area Distance value is detected, also, this method judges whether that the operation for receiving useful signal is also relatively simple.

Supersonic range finder embodiment：

Referring to Fig. 6, the structured flowchart of supersonic range finder provided in an embodiment of the present invention is shown in figure. As shown in fig. 6, the device includes：

Transmitter module 11, for controlling ultrasonic sensor to launch ultrasonic wave to determinand, and record currently First moment；

Receiving module 12, for controlling ultrasonic sensor receives echo-signal；

First processing module 13, within the default blind area time, entering in real time to the echo-signal of reception Row prime is amplified and sampling；

First comparison module 14, for by the signal intensity of the echo-signal sampled every time with measuring and depositing in advance First signal strength threshold of storage is compared；First signal strength threshold is more than the interference signal measured in advance Amplitude of the signal intensity under prime multiplication factor, and less than effective letter in the blind area distance measured in advance Number amplitude of the minimum signal strength under prime multiplication factor；

First computing module 15, within the default blind area time, if the signal of the echo-signal of sampling is strong Degree is more than the first signal strength threshold, it is determined that and useful signal is detected, and records the second current moment, Time interval between second moment and the first moment is the total duration of ultrasonic propagation；According to ultrasonic propagation Speed and total duration obtain determinand distance value.

Because ultrasonic ranging method has an above-mentioned technique effect, therefore the supersonic range finder based on this method Also there is corresponding technique effect, will not be repeated here.

Referring to Fig. 7, the another structural frames of supersonic range finder provided in an embodiment of the present invention are shown in figure Figure.As shown in fig. 7, the device includes：

Transmitter module 21, for controlling ultrasonic sensor to launch ultrasonic wave to determinand, and record currently First moment；

Receiving module 22, for controlling ultrasonic sensor receives echo-signal；

First processing module 23, within the default blind area time, entering in real time to the echo-signal of reception Row prime is amplified and sampling；

First comparison module 24, for by the signal intensity of the echo-signal sampled every time with measuring and depositing in advance First signal strength threshold of storage is compared；First signal strength threshold is more than the interference signal measured in advance Amplitude of the signal intensity under prime multiplication factor, and less than effective letter in the blind area distance measured in advance Number amplitude of the minimum signal strength under prime multiplication factor；

First computing module 25, within the default blind area time, if the signal of the echo-signal of sampling is strong Degree is more than the first signal strength threshold, it is determined that and useful signal is detected, and records the second current moment, Time interval between second moment and the first moment is the total duration of ultrasonic propagation；According to ultrasonic propagation Speed and the total duration obtain determinand distance value；

Second processing module 26, if for being not detected by useful signal within the default blind area time, pre- If the blind area time reach when, rear class amplification and sampling are carried out in real time to the echo-signal of reception, wherein, Rear class multiplication factor is more than prime multiplication factor；

Second comparison module 27, for by the signal intensity of the echo-signal sampled every time with measuring and depositing in advance The secondary signal intensity threshold of storage is compared；Secondary signal intensity threshold is the blind area distance measured in advance Outside, in the maximum range of ultrasonic sensor the minimum signal strength of useful signal under rear class multiplication factor Amplitude；

Second computing module 28, if the signal intensity of the echo-signal for sampling is more than secondary signal intensity threshold Value, it is determined that detect useful signal, and record the 3rd current moment, the 3rd moment and the first moment it Between time interval be ultrasonic propagation total duration；Institute is obtained according to the speed of ultrasonic propagation and total duration State the distance value of determinand.

Wherein, the detection time of rear class amplification is equal to the maximum range institute of ultrasonic sensor plus the blind area time The corresponding very first time.

Referring to Fig. 8, the another structural frames of supersonic range finder provided in an embodiment of the present invention are shown in figure Figure.As shown in figure 8, the device includes：

Transmitter module 801, for controlling ultrasonic sensor to launch ultrasonic wave to determinand, and record current The first moment；

Receiving module 802, for controlling ultrasonic sensor receives echo-signal；

First processing module 803, within the default blind area time, to the echo-signal of reception in real time Carry out prime amplification and sampling；

First comparison module 804, for the signal intensity of the echo-signal sampled every time to be measured simultaneously with advance First signal strength threshold of storage is compared；First signal strength threshold is more than the interference letter measured in advance Number amplitude of the signal intensity under prime multiplication factor, and less than effective in the blind area distance measured in advance Amplitude of the minimum signal strength of signal under prime multiplication factor；

First computing module 805, within the default blind area time, if the signal of the echo-signal of sampling Intensity is more than the first signal strength threshold, it is determined that and useful signal is detected, and records the second current moment, Time interval between second moment and the first moment is the total duration of ultrasonic propagation；According to ultrasonic propagation Speed and the total duration obtain determinand distance value.

Second processing module 806, if for being not detected by useful signal within the default blind area time, When the default blind area time reaches, rear class amplification and sampling are carried out in real time to the echo-signal of reception, wherein, Rear class multiplication factor is more than prime multiplication factor；

Second comparison module 807, for the signal intensity of the echo-signal sampled every time to be measured simultaneously with advance The secondary signal intensity threshold of storage is compared；Secondary signal intensity threshold is the blind area distance measured in advance Outside, in the maximum range of ultrasonic sensor the minimum signal strength of useful signal under rear class multiplication factor Amplitude；

Second computing module 808, if the signal intensity of the echo-signal for sampling is more than secondary signal intensity Threshold value, it is determined that useful signal is detected, and records the 3rd current moment, the 3rd moment and the first moment Between time interval be ultrasonic propagation total duration；Obtained according to the speed of ultrasonic propagation and total duration The distance value of the determinand；

First judge module 809, if for the very first time corresponding to the maximum range in ultrasonic sensor Useful signal is inside not detected by, then when reaching the very first time, the distance value for setting determinand is maximum range Value, and control ultrasonic sensor to launch ultrasonic wave to determinand again, re-start detection.

Referring to Fig. 9, the another structural frames of supersonic range finder provided in an embodiment of the present invention are shown in figure Figure.As shown in figure 9, the device includes：

Transmitter module 501, for controlling ultrasonic sensor to launch ultrasonic wave to determinand, and record current The first moment；

Receiving module 502, for controlling ultrasonic sensor receives echo-signal；

First processing module 503, within the default blind area time, to the echo-signal of reception in real time Carry out prime amplification and sampling；

First comparison module 504, for the signal intensity of the echo-signal sampled every time to be measured simultaneously with advance First signal strength threshold of storage is compared；First signal strength threshold is more than the interference letter measured in advance Number amplitude of the signal intensity under prime multiplication factor, and less than effective in the blind area distance measured in advance Amplitude of the minimum signal strength of signal under prime multiplication factor；

First computing module 505, within the default blind area time, if the signal of the echo-signal of sampling Intensity is more than the first signal strength threshold, it is determined that and useful signal is detected, and records the second current moment, Time interval between second moment and the first moment is the total duration of ultrasonic propagation；According to ultrasonic propagation Speed and the total duration obtain determinand distance value；

3rd processing module 506, if for being not detected by useful signal within the default blind area time, When the default blind area time reaches, the amplification of first order rear class is carried out in real time to the echo-signal of reception and adopted Sample；

3rd comparison module 507, for the signal intensity of the echo-signal sampled every time to be measured simultaneously with advance 3rd signal strength threshold of storage is compared；3rd signal strength threshold is the blind area distance measured in advance Outside, in the first order rear class detecting distance minimum signal strength of useful signal under first order rear class multiplication factor Amplitude；

3rd computing module 508, within the default first order rear class amplification detection time, if sampling The signal intensity of echo-signal is more than the 3rd signal strength threshold, it is determined that detects useful signal, and records The 4th current moment, time interval between the 4th moment and the first moment for ultrasonic propagation it is total when It is long；The distance value of determinand is obtained according to the speed of ultrasonic propagation and total duration；

Fourth processing module 509, if for when reaching the default first order rear class amplification detection time, not Useful signal is detected, then the amplification of next stage rear class and sampling are carried out in real time to the echo-signal of reception；

4th comparison module 510, for the signal intensity of the echo-signal sampled every time to be measured simultaneously with advance The l+2 signal strength thresholds of storage are compared, wherein, l is current rear class number of stages of amplification；L+2 believes Number intensity threshold be the blind area distance measured in advance is outer, in l level rear class detecting distances useful signal minimum letter Number amplitude of the intensity under next stage multiplication factor, wherein, l is the natural number not less than 2 and no more than N；

4th computing module 511, within the default next stage rear class amplification detection time, if sampling The signal intensity of the echo-signal is more than l+2 signal strength thresholds, it is determined that useful signal is detected, And the current l+3 moment is recorded, the time interval between l+3 moment and the first moment is ultrasonic propagation Total duration；The distance value of determinand is obtained according to the speed of ultrasonic propagation and total duration；

Second judge module 512, if for when reaching the default next stage rear class amplification detection time, not Useful signal is detected, then judges whether current rear class number of stages of amplification is N, if so, then setting determinand Distance value be maximum range value, and control ultrasonic sensor determinand again launch ultrasonic wave, again Detected；Otherwise, the amplification of more next stage rear class and sampling are carried out in real time to the echo-signal of reception；

Wherein, the summation of default N levels rear class amplification detection time is along with the blind area time is equal to ultrasonic wave biography The very first time corresponding to the maximum range of sensor, also, in N level rear class amplification process, amplification at different levels Multiple is all higher than the multiplication factor of previous stage.

In above-described embodiment, the device can also include：

Second transmitter module, if in the very first time corresponding to the maximum range in ultrasonic sensor not Detect useful signal, then when reaching the very first time, the distance value for setting determinand is maximum range value, And control ultrasonic sensor to launch ultrasonic wave to determinand again, re-start detection.

In above-described embodiment, the device can also include：

Measurement module, for measuring and being stored in advance under different detection total times, when echo-signal arrives Carve and at the time of echo-signal reaches each signal strength threshold between time interval, the time interval is compensation Time；

First acquisition module, for the duration difference for obtaining total duration with compensating the time；

5th computing module, the distance of determinand is obtained for the spread speed according to ultrasonic wave and duration difference Value.

In above-described embodiment, the device can also include：

Second acquisition module, for obtaining the environment temperature residing for ultrasonic wave；

Second acquisition module, for obtaining the actual propagation speed of ultrasonic wave according to environment temperature；

6th computing module, for according to the actual propagation speed and total duration of ultrasonic wave obtain determinand away from From value.

To sum up, the distance value for the determinand that the supersonic range finder can be pointed in the distance of blind area is examined Survey, also, it judges whether that the operation for receiving useful signal is also relatively simple.

Ultrasonic ranging system embodiment：

Referring to Figure 10, the structural representation of ultrasonic ranging system provided in an embodiment of the present invention is shown in figure Figure.As shown in Figure 10, the present embodiment includes：Ultrasonic sensor (only shows its transmitting terminal 2 and connect in figure Receiving end 3) and it is connected to the controller 1 of ultrasonic sensor.Wherein, ultrasonic sensor is used to launch ultrasound Ripple and receives echo-signal.Controller 1 was used within the default blind area time, to the echo-signal received Prime amplification and sampling are carried out in real time, and by the signal intensity of the echo-signal sampled every time with measuring in advance And the first signal strength threshold stored is compared；First signal strength threshold is more than the interference measured in advance Amplitude of the signal intensity of signal under prime multiplication factor, and less than the minimum of the useful signal measured in advance Amplitude of the signal intensity under prime multiplication factor；Within the default blind area time, if the echo-signal of sampling Signal intensity be more than the first signal strength threshold, it is determined that detect useful signal, and record current the Two moment, the time interval between the second moment and the first moment are the total duration of ultrasonic propagation；According to super The speed and total duration of Acoustic Wave Propagation obtain the distance value of determinand.

As shown in Figure 10, the controller 1 can be MCU control unit, and MCU control unit can have ADC, two IO (Input/Outerput, input/output) mouths, and I2C (Intel-Integrated Circuit). Wherein, an I/O port is connected with ultrasonic sensor, leads to the square wave excitation of 40KHz caused by the I/O port The transmitting terminal 2 through ultrasonic sensor is sent after over level conversion, and another I/O port is connected with temperature measurement module 4 Connect, to detect environment temperature in real time.ADC successively with amplifying circuit and the receiving terminal 3 of ultrasonic sensor It is connected, makes quilt after the amplified circuit amplification of the echo-signal in the ultrasonic wave that ultrasonic sensor receives ADC is sampled, and then judges whether to connect according to whether the ADC under AWD mode of operations occurs to interrupt It has received useful signal.I2C is used for being communicated with host computer.

Specifically, ultrasonic sensor can be transmitting-receiving integrated sensor or the split type sensor of transmitting-receiving.

Because the ultrasonic ranging method has an above-mentioned technique effect, therefore the ultrasonic ranging system based on this method System also has corresponding technique effect.

It should be noted that herein, such as first and second or the like relational terms be used merely to by One entity or operation make a distinction with another entity or operation, and not necessarily require or imply these Any this actual relation or order be present between entity or operation.Moreover, term " comprising ", " bag Containing " or any other variant thereof is intended to cover non-exclusive inclusion, so that including a series of elements Process, method, article or equipment not only include those key elements, but also including being not expressly set out Other element, or also include for this process, method, article or the intrinsic key element of equipment. In the case of more limiting, the key element that is limited by sentence "including a ...", it is not excluded that including Other identical element also be present in the process of the key element, method, article or equipment.

Each embodiment in this specification is described by the way of related, identical phase between each embodiment As part mutually referring to, what each embodiment stressed be it is different from other embodiment it Place.For system embodiment, because it is substantially similar to embodiment of the method, so description Fairly simple, the relevent part can refer to the partial explaination of embodiments of method.

The foregoing is merely illustrative of the preferred embodiments of the present invention, is not intended to limit the protection model of the present invention Enclose.Any modification, equivalent substitution and improvements made within the spirit and principles of the invention etc., are wrapped Containing within the scope of the present invention.

Claims (14)

1. a kind of ultrasonic ranging method, it is characterised in that comprise the following steps：

Control ultrasonic sensor to launch ultrasonic wave to determinand, and record the first current moment；

Control ultrasonic sensor receives echo-signal；

Within the default blind area time, prime amplification and sampling are carried out in real time to the echo-signal of reception；

By the signal intensity of the echo-signal sampled every time and the first signal intensity threshold in advance measuring and store Value is compared；First signal strength threshold is more than the signal intensity of the interference signal measured in advance preceding Amplitude under level multiplication factor, and it is strong less than the minimum signal of the useful signal in the blind area distance measured in advance Spend the amplitude under prime multiplication factor；

Within the default blind area time, if the signal intensity of the echo-signal of sampling is more than the first signal intensity threshold Value, it is determined that detect useful signal, and record the second current moment, second moment and described the Time interval between one moment is the total duration of ultrasonic propagation；According to the speed of ultrasonic propagation and described Total duration obtains the distance value of the determinand.

2. according to the method for claim 1, it is characterised in that also include：

If being not detected by useful signal within the default blind area time, when reaching the default blind area time, Rear class amplification and sampling are carried out in real time to the echo-signal of reception；Wherein, rear class multiplication factor is more than prime Multiplication factor；By the signal intensity of the echo-signal sampled every time and the second letter in advance measuring and store Number intensity threshold is compared；The secondary signal intensity threshold is that the blind area distance measured in advance is outer, ultrasonic Amplitude of the minimum signal strength of useful signal under rear class multiplication factor in the maximum range of wave sensor；

If the signal intensity of the echo-signal of sampling is more than secondary signal intensity threshold, it is determined that detects Useful signal, and record the 3rd current moment, the time between the 3rd moment and first moment At intervals of the total duration of ultrasonic propagation；Treated according to obtaining the speed of ultrasonic propagation and the total duration Survey the distance value of thing；

Wherein, the detection time of the rear class amplification is equal to the ultrasonic sensor plus the blind area time Maximum range corresponding to the very first time.

3. according to the method for claim 2, it is characterised in that also include：

If being not detected by useful signal in the very first time corresponding to the maximum range in ultrasonic sensor, When reaching the very first time, the distance value for setting the determinand is maximum range value, and controls the ultrasound Wave sensor launches ultrasonic wave to determinand again, re-starts detection.

4. according to the method for claim 1, it is characterised in that default rear class number of stages of amplification is N, N For the natural number not less than 2, this method also includes：

If being not detected by useful signal within the default blind area time, step is performed：

A1, when reaching the default blind area time, first order rear class is carried out in real time to the echo-signal of reception Amplification and sampling；

A2, by the signal intensity of the echo-signal sampled every time and the 3rd signal that in advance measures and store Intensity threshold is compared；3rd signal strength threshold is the blind area measured in advance apart from the outer, first order Amplitude of the minimum signal strength of useful signal under first order rear class multiplication factor in rear class detecting distance；

A3, within the default first order rear class amplification detection time, if sampling the echo-signal signal Intensity is more than the 3rd signal strength threshold, it is determined that and useful signal is detected, and records the 4th current moment, Time interval between 4th moment and first moment is the total duration of ultrasonic propagation；According to super The speed of Acoustic Wave Propagation and the total duration obtain the distance value of the determinand；

If when reaching the default first order rear class amplification detection time, useful signal is not detected by, then

B1, the echo-signal to reception carry out the amplification of next stage rear class and sampling in real time；

B2, the signal intensity of the echo-signal sampled every time believed with the l+2 in advance measuring and storing Number intensity threshold is compared, wherein, l is current rear class number of stages of amplification, the l+2 signal intensity thresholds Outside the blind area distance for being worth to measure in advance, the minimum signal strength of useful signal exists in l level rear class detecting distances Amplitude under next stage multiplication factor, wherein, l is the natural number not less than 2 and no more than N；

B3, within the default next stage rear class amplification detection time, if sampling the echo-signal signal Intensity is more than l+2 signal strength thresholds, it is determined that when detecting useful signal, and recording current l+3 Carve, the time interval between the l+3 moment and first moment is the total duration of ultrasonic propagation； The distance value of the determinand is obtained according to the speed of ultrasonic propagation and the total duration；

If B4, when reaching the default next stage rear class amplification detection time, useful signal is not detected by, then Perform step：

C1, judge whether current rear class number of stages of amplification is N, if so, then setting the distance of the determinand It is worth for maximum range value, and controls the ultrasonic sensor to launch ultrasonic wave to determinand again, enters again Row detection；Otherwise, return and perform the step B1；

Wherein, the summation of the default N levels rear class amplification detection time was equal to along with the blind area time The very first time corresponding to the maximum range of the ultrasonic sensor, also, in N level rear class amplification process, Multiplication factor at different levels is all higher than the multiplication factor of previous stage.

5. according to the method any one of claim 1-4, it is characterised in that also include：

Measure and be stored under different detection total times in advance, the echo-signal arrival moment reaches with echo-signal Time interval between at the time of each signal strength threshold, the time interval are the compensation time；

Obtain the total duration and the duration difference of the compensation time；

The distance value that determinand is obtained according to ultrasonic propagation velocity and total duration, it is：According to ultrasonic wave Spread speed and the duration difference obtain the distance value of the determinand.

6. according to the method any one of claim 1-4, it is characterised in that also include：

Obtain the environment temperature residing for the ultrasonic wave；

The actual propagation speed of the ultrasonic wave is obtained according to the environment temperature；

The distance value that determinand is obtained according to ultrasonic propagation velocity and total duration, it is：According to described super The actual propagation speed of sound wave and the total duration obtain the distance value of the determinand.

A kind of 7. supersonic range finder, it is characterised in that including：

Transmitter module, for controlling ultrasonic sensor to launch ultrasonic wave to determinand, and record current the One moment；

Receiving module, for controlling ultrasonic sensor receives echo-signal；

First processing module, within the default blind area time, being carried out in real time to the echo-signal of reception Prime is amplified and sampling；

First comparison module, for by the signal intensity of the echo-signal sampled every time with measuring and storing in advance The first signal strength threshold be compared；First signal strength threshold is more than the interference letter measured in advance Number amplitude of the signal intensity under prime multiplication factor, and less than effective in the blind area distance measured in advance Amplitude of the minimum signal strength of signal under prime multiplication factor；

First computing module, within the default blind area time, if the signal intensity of the echo-signal of sampling More than the first signal strength threshold, it is determined that detect useful signal, and record the second current moment, institute State the total duration that the time interval between the second moment and first moment is ultrasonic propagation；According to ultrasound Speed and the total duration that ripple is propagated obtain the distance value of the determinand.

8. device according to claim 7, it is characterised in that also include：

Second processing module, if for being not detected by useful signal within the default blind area time, default The blind area time reach when, rear class amplification and sampling are carried out in real time to the echo-signal of reception, wherein, after Level multiplication factor is more than prime multiplication factor；

Second comparison module, for the signal intensity of the echo-signal sampled every time to be measured simultaneously with advance The secondary signal intensity threshold of storage is compared；The secondary signal intensity threshold is the blind area measured in advance The minimum signal strength of useful signal is in rear class multiplication factor in outer, ultrasonic sensor maximum range Under amplitude；

Second computing module, if the signal intensity of the echo-signal for sampling is more than secondary signal intensity Threshold value, it is determined that detect useful signal, and record the 3rd current moment, the 3rd moment with it is described Time interval between first moment is the total duration of ultrasonic propagation；According to the speed of ultrasonic propagation and institute State the distance value that total duration obtains the determinand；

Wherein, the detection time of the rear class amplification is equal to the ultrasonic sensor plus the blind area time Maximum range corresponding to the very first time.

9. device according to claim 8, it is characterised in that also include：

First judge module, if in the very first time corresponding to the maximum range in ultrasonic sensor not Useful signal is detected, then when reaching the very first time, the distance value for setting the determinand is maximum range Value, and control the ultrasonic sensor to launch ultrasonic wave to determinand again, re-start detection.

10. device according to claim 7, it is characterised in that default rear class number of stages of amplification is N, N For the natural number not less than 2, the device also includes：

3rd processing module, if for being not detected by useful signal within the default blind area time, default The blind area time reach when, the amplification of first order rear class and sampling are carried out in real time to the echo-signal of reception；

3rd comparison module, for the signal intensity of the echo-signal sampled every time to be measured simultaneously with advance 3rd signal strength threshold of storage is compared；3rd signal strength threshold is the blind area measured in advance The minimum signal strength of useful signal is in first order rear class times magnification in outer, first order rear class detecting distance Amplitude under several；

3rd computing module, within the default first order rear class amplification detection time, if sampling is described The signal intensity of echo-signal is more than the 3rd signal strength threshold, it is determined that detects useful signal, and records The 4th current moment, the time interval between the 4th moment and first moment is ultrasonic propagation Total duration；The distance value of the determinand is obtained according to the speed of ultrasonic propagation and the total duration；

Fourth processing module, if for when reaching the default first order rear class amplification detection time, not detecting To useful signal, then the amplification of next stage rear class and sampling are carried out in real time to the echo-signal of reception；

4th comparison module, for the signal intensity of the echo-signal sampled every time to be measured simultaneously with advance The l+2 signal strength thresholds of storage are compared, wherein, l is current rear class number of stages of amplification, described the L+2 signal strength thresholds are the blind area measured in advance useful signal in outer, l level rear class detecting distances Amplitude of the minimum signal strength under next stage multiplication factor, wherein, l is not less than 2 and no more than N's Natural number；

4th computing module, within the default next stage rear class amplification detection time, if sampling is described The signal intensity of echo-signal is more than l+2 signal strength thresholds, it is determined that detects useful signal, and remembers At the record current l+3 moment, the time interval between the l+3 moment and first moment is ultrasonic wave The total duration of propagation；The distance of the determinand is obtained according to the speed of ultrasonic propagation and the total duration Value；

Second judge module, if for when reaching the default next stage rear class amplification detection time, not detecting To useful signal, then judge whether current rear class number of stages of amplification is N, if so, then set determinand away from It is maximum range value from value, and controls ultrasonic sensor to launch ultrasonic wave to determinand again, re-starts Detection；Otherwise, the amplification of more next stage rear class and sampling are carried out in real time to the echo-signal of reception；

Wherein, the summation of the default N levels rear class amplification detection time was equal to along with the blind area time The very first time corresponding to the maximum range of the ultrasonic sensor, also, in N level rear class amplification process, Multiplication factor at different levels is all higher than the multiplication factor of previous stage.

11. according to the device any one of claim 7-10, it is characterised in that also include：

Measurement module, for measuring and being stored in advance under different detection total times, when echo-signal arrives Carve and at the time of echo-signal reaches each signal strength threshold between time interval, the time interval is compensation Time；

First acquisition module, for obtaining the total duration and the duration difference of the compensation time；

5th computing module, obtained for the spread speed according to ultrasonic wave and the duration difference described to be measured The distance value of thing.

12. according to the device any one of claim 7-10, it is characterised in that also include：

Second acquisition module, for obtaining the environment temperature residing for the ultrasonic wave；

Second acquisition module, for obtaining the actual propagation speed of the ultrasonic wave according to the environment temperature；

6th computing module, institute is obtained for the actual propagation speed according to the ultrasonic wave and the total duration State the distance value of determinand.

A kind of 13. ultrasonic ranging system, it is characterised in that including：Ultrasonic sensor and it is connected to institute State the controller of ultrasonic sensor；Wherein,

The ultrasonic sensor is used to launch ultrasonic wave and receives echo-signal；

The controller was used within the default blind area time, before being carried out in real time to the echo-signal received Level amplification and sampling, and by the signal intensity of the echo-signal sampled every time with advance measure and store first Signal strength threshold is compared；First signal strength threshold is more than the interference signal measured in advance Amplitude of the signal intensity under prime multiplication factor, and less than the minimum signal of the useful signal measured in advance Amplitude of the intensity under prime multiplication factor；Within the default blind area time, if the letter of the echo-signal of sampling Number intensity is more than the first signal strength threshold, it is determined that useful signal is detected, according to detecting useful signal At the time of and ultrasonic wave at the time of launch between time interval obtain the total duration of ultrasonic propagation, and according to The speed and total duration of ultrasonic propagation obtain the distance value of the determinand.

14. system according to claim 13, it is characterised in that the ultrasonic sensor is transmitting-receiving Integral sensor or the split type sensor of transmitting-receiving.