Ultrasonic distance measurement method and system

Abstract

The present invention discloses an ultrasonic ranging method and system. In view of the problems existing in the prior art that when the sensitivity of the detection product fluctuates greatly, the actual angle will be affected; and the detection process is cumbersome and the detection envelope needs to filter the interference targets in sequence, the technical scheme of the present invention includes: constructing a first threshold through the farthest distance of ultrasonic detection and the measured distance of the target to eliminate the influence of the side lobe on the test; constructing a second threshold through distance attenuation and air absorption attenuation to constrain the long-distance angle; and constraining the short-distance angle by setting the farthest distance sensitivity and setting the third threshold. Its purpose is to be able to perform stable ultrasonic ranging through the ultrasonic ranging method of the present application.

Description

Technical Field

[0001] The present invention belongs to the technical field of ultrasonic detection, and in particular relates to an ultrasonic distance measurement method and system. Background Art

[0002] Because ultrasonic waves have strong directivity, slow energy consumption, and can propagate over long distances in the medium, they are often used to measure distance.

[0003] In ultrasonic ranging applications, the product's measured distance is often greater than the actual use distance, resulting in high sensitivity. At the same time, the detectable area is large, and other targets on both sides are prone to interference. The existing method is to set different thresholds at different distances to avoid the problem of high sensitivity, or to filter out other targets through interference learning.

[0004] Problems with existing technologies:

[0005] By setting different thresholds at different distances, when the sensitivity of the detection product fluctuates greatly, it will affect the actual angle; when filtering out targets through interference learning, the process is more cumbersome and it is necessary to filter out interference targets in the detection envelope one by one. Summary of the invention

[0006] In view of the problems in the prior art that when the sensitivity of the detection product fluctuates greatly, the actual angle will be affected; and the detection process is cumbersome and it is necessary to filter the interference targets of the detection envelope in sequence, the present invention proposes an ultrasonic ranging method and system, the purpose of which is to enable stable ultrasonic ranging through the ultrasonic ranging method of the present application.

[0007] To achieve the above-mentioned purpose, the present invention adopts a technical solution, which proposes an ultrasonic ranging method comprising:

[0008] S1: construct a first threshold value by using the farthest distance detected by ultrasonic wave and the measured distance of the target to eliminate the influence of side lobes on the test;

[0009] S2: construct the second threshold through distance attenuation and air absorption attenuation to constrain the long-distance angle;

[0010] S3: Constrain the close-range angle by setting the maximum distance sensitivity and setting the third threshold.

[0011] Preferably, in S1 of the present invention, the first threshold value constructed is:

[0012]

[0013] Among them, E0 represents the minimum threshold, d represents the measured distance, and dmax represents the maximum distance detected by ultrasonic wave.

[0014] Preferably, in S2 of the present invention, the second threshold value constructed is:

[0015]

[0016] Among them, E0 represents the minimum threshold, d represents the measured distance, dmax represents the farthest distance of ultrasonic detection, k1 represents the angle adjustment factor, k2 is the coefficient of frequency attenuation, and the number 2 represents the back and forth of sound waves. When the ultrasonic wave is separated into a transmitting and receiving part, the value is 1.

[0017] Preferably, in S3 of the present invention, the third threshold is:

[0018] E3=Eteach*k3

[0019] Among them, Eteach represents the ultrasonic echo sensitivity corresponding to the farthest detection distance, and k3 represents the safety factor, and the coefficient range is 0-1.

[0020] The present invention also proposes an ultrasonic ranging system, comprising:

[0021] Side lobe elimination module: a first threshold is constructed by the maximum distance detected by ultrasonic wave and the measured distance of the target, so as to eliminate the influence of side lobe on the test;

[0022] Constrained long-distance angle module: The second threshold is constructed through distance attenuation and air absorption attenuation to constrain long-distance angles;

[0023] Constrained close-range angle module: used to constrain close-range angles by setting the maximum distance sensitivity and setting the third threshold.

[0024] Preferably, in the sidelobe elimination module of the present invention, the first threshold value constructed is:

[0025]

[0026] Among them, E0 represents the minimum threshold, d represents the measured distance, and dmax represents the maximum distance detected by ultrasonic wave.

[0027] Preferably, in the long-distance angle constraint module of the present invention, the second threshold value constructed is:

[0028]

[0029] Among them, E0 represents the minimum threshold, d represents the measured distance, dmax represents the farthest distance of ultrasonic detection, k1 represents the angle adjustment factor, k2 is the coefficient of frequency attenuation, and the number 2 represents the back and forth of sound waves. When the ultrasonic wave is separated into a transmitting and receiving part, the value is 1.

[0030] Preferably, in the close-distance angle constraint module of the present invention, the third threshold is:

[0031] E3=Eteach*k3

[0032] Among them, Eteach represents the ultrasonic echo sensitivity corresponding to the farthest detection distance, and k3 represents the safety factor, and the coefficient range is 0-1.

[0033] Compared with the prior art, the technical solution of the present invention has the following advantages / benefits:

[0034] 1. The present invention not only eliminates the influence of side lobes, but also can adjust the angle according to the customer's usage environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0035] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. It should be understood that the following drawings only show certain embodiments of the present invention and therefore should not be regarded as limiting the scope. For ordinary technicians in this field, other related drawings can be obtained based on these drawings without paying creative work.

[0036] Figure 1 It is a schematic diagram of constraining a long-distance angle according to Embodiment 1 of the present invention.

[0037] Figure 2 It is a schematic diagram of constraining a long-distance angle according to Embodiment 1 of the present invention.

[0038] Figure 3 It is a schematic diagram of constraining the close-range angle according to embodiment 1 of the present invention.

[0039] Figure 4 It is a schematic diagram of various thresholds in Example 1 of the present invention.

[0040] Figure 5 It is a schematic diagram of the process of distance collection in Example 1 of the present invention. DETAILED DESCRIPTION

[0041] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions in the embodiments of the present invention are clearly and completely described below. Obviously, the described embodiments are part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in the field without creative work are within the scope of protection of the present invention. Therefore, the detailed description of the embodiments of the present invention provided below is not intended to limit the scope of the claimed invention, but merely represents the selected embodiments of the present invention.

[0042] Embodiment 1:

[0043] like Figure 1 , Figure 2, Figure 3 and Figure 4 As shown, the present invention proposes an ultrasonic ranging method comprising:

[0044] S1: The first threshold is constructed by the maximum distance detected by ultrasonic wave and the measured distance of the target to eliminate the influence of the side lobe on the test; the constructed first threshold is:

[0045]

[0046] Among them, E0 represents the minimum threshold, d represents the measured distance, and dmax represents the maximum distance detected by ultrasonic wave.

[0047] S2: The second threshold is constructed through distance attenuation and air absorption attenuation to constrain the long-distance angle; through distance attenuation and air absorption attenuation, that is, the corresponding relationship between sensitivity and distance, the advantage is that the angle can be further reduced, and the minimum can be close to zero degrees, such as Figure 1 and Figure 2 The figure shows the constrained long-distance angle. The light color is the original coverage map, and the dark color is the coverage map of the present embodiment 1. Figure 3 It can be seen that the minimum can approach zero degrees.

[0048] The second threshold constructed is:

[0049]

[0050] Among them, E0 represents the minimum threshold, d represents the measured distance, dmax represents the farthest distance of ultrasonic detection, k1 represents the angle adjustment factor, k2 is the coefficient of frequency attenuation, and the number 2 represents the back and forth of sound waves. When the ultrasonic wave is separated into a transmitting and receiving part, the value is 1.

[0051] S3: By setting the maximum distance sensitivity and the third threshold, the close distance angle is restricted. Figure 3 As shown, by setting the third threshold value of the maximum distance sensitivity, the advantage is that the angle change can be kept small, the sensitivity consistency of the calibration product, that is, the detection angle consistency, and the detection area is based on the actual demand area, that is Figure 3 The detection distance of the medium and dark coverage map. The dark gray is the actual required detection distance of 0.7 meters, and the light gray is the maximum design distance of the product of 1.6 meters.

[0052] Normally, when the target is in the light gray area, it will also be detected. Obviously, the angle is greater than our expectation.

[0053] When the learning distance is passed: However, the ultrasonic sensitivity itself fluctuates, and the target jitters. To ensure stable detection at the farthest distance, the third threshold is set as:

[0054] E3=Eteach*k3

[0055] Among them, Eteach represents the ultrasonic echo sensitivity corresponding to the farthest detection distance, and k3 represents the safety factor, which ranges from 0 to 1. The smaller the coefficient, the greater the fluctuation of the product echo sensitivity is allowed to be; the larger the coefficient, the greater the effect of reducing the angle. The effect diagram is as follows Figure 4 shown.

[0056] When the fluctuation is small, the coefficient approaches 1, and when the fluctuation is large, the coefficient approaches 0 (but not too small, the threshold multiplied by the coefficient must still be greater than the noise). At the same time, in order to reduce the fluctuation, multiple data processing can be used for judgment, such as taking the average of 5 groups, or taking the average after removing outliers, or the median, etc., all of which can reduce the fluctuation.

[0057] The present invention also proposes an ultrasonic ranging system, comprising:

[0058] Side lobe elimination module: The first threshold is constructed by the maximum distance detected by ultrasonic wave and the measured distance of the target, so as to eliminate the influence of the side lobe on the test; the constructed first threshold is:

[0059]

[0060] Among them, E0 represents the minimum threshold, d represents the measured distance, and dmax represents the maximum distance detected by ultrasonic wave.

[0061] Constrained long-distance angle module: The second threshold is constructed through distance attenuation and air absorption attenuation to constrain the long-distance angle; the constructed second threshold is:

[0062]

[0063] Among them, E0 represents the minimum threshold, d represents the measured distance, dmax represents the farthest distance of ultrasonic detection, k1 represents the angle adjustment factor, k2 is the coefficient of frequency attenuation, and the number 2 represents the back and forth of sound waves. When the ultrasonic wave is separated into a transmitting and receiving part, the value is 1.

[0064] Close-range angle constraint module: It is used to constrain close-range angles by setting the maximum distance sensitivity and the third threshold. The third threshold is:

[0065] E3=Eteach*k3

[0066] Among them, Eteach represents the ultrasonic echo sensitivity corresponding to the farthest detection distance, and k3 represents the safety factor, which ranges from 0 to 1. The smaller the coefficient, the greater the fluctuation of the product echo sensitivity is allowed to be; the larger the coefficient, the greater the effect of reducing the angle.

[0067] The process of distance measurement is to find the distance point. In the first embodiment, a threshold is defined and then the intersection point is found as the distance calculation point. The specific method is: a constant threshold is set as a threshold related to the distance, which reduces the blind spot on the one hand and compensates for the deviation caused by finding the point on the other hand.

[0068] like Figure 5 As shown, the process of distance acquisition in this embodiment 1 is: first determine whether it is a secondary acquisition flag, if so, configure the secondary ADC and complete the data acquisition flag, if not, use the primary ADC configuration; then perform noise acquisition, transmit ultrasonic pulses, and then perform ADC data acquisition, perform IIR filtering on the collected data, and finally calculate the distance by finding the distance point.

[0069] The above are only preferred embodiments of the present invention. It should be noted that the above preferred embodiments should not be regarded as limiting the present invention, and the protection scope of the present invention should be based on the scope defined by the claims. For ordinary technicians in this technical field, several improvements and modifications can be made without departing from the spirit and scope of the present invention, and these improvements and modifications should also be regarded as the protection scope of the present invention.

Claims

1. An ultrasonic distance measurement method, characterized in that: include: S1: construct a first threshold value by using the farthest distance detected by ultrasonic wave and the measured distance of the target to eliminate the influence of side lobes on the test; S2: construct the second threshold through distance attenuation and air absorption attenuation to constrain the long-distance angle; S3: constraining the close-range angle by setting the maximum distance sensitivity and setting the third threshold; In S1, the first threshold constructed is: E1= Among them, E0 represents the minimum threshold, d represents the measured distance, and dmax represents the maximum distance detected by ultrasonic wave; In S2, the second threshold constructed is: E2= Among them, E0 represents the minimum threshold, d represents the measured distance, dmax represents the farthest distance detected by ultrasonic wave, k1 represents the angle adjustment factor, k2 represents the coefficient of frequency attenuation, and the number 2 represents the round trip of sound waves. When the ultrasonic wave is separated into a transmitting and receiving part, the value is 1. In S3, the third threshold is: E3=Eteach*k3 Among them, Eteach represents the ultrasonic echo sensitivity corresponding to the farthest detection distance, and k3 represents the safety factor, and the coefficient range is 0-1.

2. An ultrasonic ranging system, characterized in that: include: Side lobe elimination module: a first threshold is constructed by the maximum distance detected by ultrasonic wave and the measured distance of the target, so as to eliminate the influence of side lobe on the test; Constrained long-distance angle module: The second threshold is constructed through distance attenuation and air absorption attenuation to constrain long-distance angles; Close-range angle constraint module: used to constrain close-range angles by setting the maximum distance sensitivity and setting the third threshold; In the sidelobe elimination module, the first threshold constructed is: E1= Among them, E0 represents the minimum threshold, d represents the measured distance, and dmax represents the maximum distance detected by ultrasonic wave; In the Constrained Distance Angle module, the second threshold is constructed as: E2= Among them, E0 represents the minimum threshold, d represents the measured distance, dmax represents the farthest distance detected by ultrasonic wave, k1 represents the angle adjustment factor, k2 represents the coefficient of frequency attenuation, and the number 2 represents the round trip of sound waves. When the ultrasonic wave is separated into a transmitting and receiving part, the value is 1. In the constrained close-range angle module, the third threshold is: E3=Eteach*k3 Among them, Eteach represents the ultrasonic echo sensitivity corresponding to the farthest detection distance, and k3 represents the safety factor, and the coefficient range is 0-1.

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