TWI749951B - Ultrasonic sensor module - Google Patents

Abstract

An ultrasonic sensor module comprising a housing, an ultrasonic transmitter and an ultrasonic receiver. The housing comprises a first surface, which has a first opening, a second opening, and at least one slot. The slot is located between the first opening and the second opening. The ultrasonic transmitter is disposed in the housing for transmitting sound wave through the first opening. The ultrasonic receiver is disposed in the housing for receiving sound wave through the second opening. The slot has a width determined by the formula: w = L (n + 1/m), wherein w is the width, m is an integer equal to or greater than zero, L is a wavelength of the sound wave transmitted by the ultrasonic transmitter, and m is a value between 3 to 16.

Description

Ultrasonic sensor module

This case is about an ultrasonic sensor.

The traditional ultrasonic sensor uses the transmitting end to emit sound waves to an object to be measured, and then uses the receiving end to receive the reflected sound waves to detect the distance between the ultrasonic sensor and the object to be measured.

However, in actual use, it is easy to encounter the direct diffraction of the sound wave from the transmitting end to the receiving end, which causes problems with the ranging function and makes the ultrasonic sensor misjudge.

According to an embodiment of this case, this case provides an ultrasonic sensor module. The ultrasonic sensor module includes a housing, an ultrasonic transmitter unit and an ultrasonic receiver unit. The housing includes a first surface. The first surface includes a first opening, a second opening and at least one groove. The groove is located between the first opening and the second opening. The ultrasonic transmitting unit is arranged in the casing and emits sound waves to the outside through the first opening. The ultrasonic receiving unit is arranged in the casing and receives sound waves through the second opening. Wherein, the groove has a width, and the width satisfies the following formula: w = L (n + 1/m); where w is the width, n is an integer greater than or equal to zero, and L is one of the sound waves emitted by the ultrasonic emission unit The wavelength, m is a value between 3 and 16.

There is at least one groove between the first opening and the second opening of the housing of the ultrasonic sensor module in this case. The groove has a specific width. The sound waves diffracted by the ultrasonic transmitter unit to the surface of the housing will be in this groove. The back and forth reflection in the groove reduces its intensity. In this way, the sound waves diffracted from the ultrasonic transmitter unit to the ultrasonic receiver unit can be effectively eliminated, and the ultrasonic sensor can avoid misjudgment.

The specific implementation of this case will be described in more detail below in conjunction with the schematic diagram. According to the following description and the scope of patent application, the advantages and features of this case will be clearer. It should be noted that the drawings are in a very simplified form and all use imprecise proportions, which are only used to conveniently and clearly assist in explaining the purpose of the embodiments of this case.

The first figure is a three-dimensional schematic diagram of the first embodiment of the ultrasonic sensor module in this case. The second to fourth figures are corresponding to a schematic front view, a schematic side view, and a schematic top view of the ultrasonic sensor module. The fifth figure is a schematic cross-sectional view corresponding to the A-A section in the third figure. In one embodiment, the ultrasonic sensor module 100 can be applied to robot-related products, such as industrial robots, toy robots, Lego robots, sweeping robots, etc., to detect the external environment and avoid collisions.

As shown in the first figure, the ultrasonic sensor module 100 includes a housing 120, an ultrasonic transmitter unit 140, and an ultrasonic receiver unit 160.

The casing 120 includes a first surface 121 and a second surface 122. The first surface 121 includes a first opening 123, a second opening 124, and at least one groove (three grooves 125a, 125b, and 125c are taken as an example in the figure). The ultrasonic transmitting unit 140 is disposed in the casing 120 and emits sound waves to the outside through the first opening 123. The ultrasonic receiving unit 160 is disposed in the housing 120 and receives sound waves through the second opening 124. The grooves 125a, 125b, and 125c are located between the first opening 123 and the second opening 124.

In one embodiment, the side of the housing 120 is provided with a connector 180 for providing the electrical energy required for the operation of the ultrasonic sensor module 100, and used for the detection signal generated by the ultrasonic sensor module 100 Outward transmission.

In an embodiment, as shown in FIG. 5, a spacer layer 170 may be provided between the ultrasonic transmitting unit 140 and the ultrasonic receiving unit 160 for separation. The spacer layer 170 is located in the housing 120. In an embodiment, the spacer layer 170 may be filled with a sound-absorbing material, such as foam.

In this embodiment, the grooves 125a, 125b, and 125c have the same width w, and the width w satisfies the following formula: w = L(n + 1/m); where w is the width and n is greater than or equal to zero An integer of, L is the wavelength of the sound wave emitted by the ultrasonic transmitting unit 140, and m is a value between 3-16.

This width setting can avoid the generation of standing waves in the grooves 125a, 125b, and 125c, so that the sound waves diffracted on the surface of the housing 120 can be reflected back and forth in the grooves 125a, 125b, and 125c to reduce its intensity. At the same time, the width of the trenches 125a, 125b, and 125c is too narrow to affect the manufacturing process. In this way, the sound waves diffracted from the ultrasonic transmitting unit 140 to the ultrasonic receiving unit 160 can be effectively eliminated.

In one embodiment, as shown in the second figure, the length of the grooves 125a, 125b, and 125c is approximately equal to the width of the first opening 123 or the second opening 124. But it is not limited to this. In other embodiments, the length of the grooves 125a, 125b, and 125c is greater than 1/2 the width of the first opening 123 or the second opening 124, which can effectively reduce the diffracted sound waves.

In one embodiment, as shown in the second figure, the first opening 123 is circular, and the second opening 124 is circular to match the transmission end of the ultrasonic transmitting unit 140 and the receiving end of the ultrasonic receiving unit 160. Appearance. The center of the first opening 123 and the center of the second opening 124 define a center line LM (that is, the line connecting the center of the first opening 123 and the center of the second opening 124). These grooves 125a, 125b, 125c are symmetrically distributed on both sides of the center line LM.

In one embodiment, as shown in the second figure, the grooves 125a, 125b, and 125c all extend along the linear direction D1, and the extending direction is perpendicular to the center line LM. But it is not limited to this. In other embodiments, the grooves 125a, 125b, and 125c can also be arranged on the first surface 121 in an oblique direction according to actual requirements. Moreover, in other embodiments, the extending direction of each trench 125a, 125b, 125c can also be different.

In one embodiment, as shown in the second figure, the three grooves 125a, 125b, 125c are arranged parallel to each other between the first opening 123 and the second opening 124, and two adjacent grooves 125a, 125b, The separation distance g of 125c is kept constant. But it is not limited to this. In other embodiments, because the sound waves generated by the ultrasonic transmitting unit 140 may slightly change, the spacing distance g of the grooves 125a, 125b, and 125c can be designed with different spacing distances in response to this change.

In one embodiment, as shown in the second figure, the extending directions of the grooves 125a, 125b, and 125c are parallel to each other, and the width w of the grooves 125a, 125b, and 125c is the same. However, it is not limited to this. In other embodiments, because the sound waves generated by the ultrasonic transmitting unit 140 will slightly change, the grooves 125a, 125b, and 125c can be designed with different widths in response to this change. However, these widths must satisfy the aforementioned formula: w = L (n + 1/m), and m is a value between 3 and 16. In one embodiment, the distance g between the trenches 125a, 125b, and 125c may be greater than or equal to the width w of the trenches.

The second surface 122 includes a plurality of connecting structures 1222 arranged in an array. In one embodiment, these connecting structures 1222 are circular. These connecting structures 1222 can be used to connect with other surfaces or elements having corresponding connecting structures. Thereby, the ultrasonic sensor module 100 of the present application can be easily fixed at the desired installation position in a module manner.

In one embodiment, the housing 120 is substantially a rectangular parallelepiped, and the second surface 122 and the first surface 121 are located on opposite sides of the housing. But it is not limited to this. In one embodiment, according to actual requirements, the second surface 122 for installation and the first surface 121 for sensing may also be located on two adjacent sides of the housing 120 to provide different installation methods.

The following table (Table 1) presents the improvement degree of the diffracted acoustic wave by the ultrasonic sensor module configured according to the first embodiment of the present case with experimental data. D in the table is the distance from the center of the first opening 123 to the center of the second opening 124. The diffraction increment caused by the shell is to compare the intensity of the diffraction signal before and after the shell is installed. The lower the value, the better the improvement of the diffraction. The first control sample in the table is an ultrasonic sensor module without grooves. The groove width of the control sample 2 is relatively large, and its corresponding m value is 2.01, which does not fall within the range set in this case (that is, a value between 3 and 16). Both sample 1 and sample 2 adopt the configuration of the first embodiment of this case, but their groove widths are different. Control sample one (without grooves) Control sample 2 (larger groove width) Sample one Sample two n N/A 0 0 0 m N/A 2.01 4.02 5.41 w(mm) N/A 4.3 2.15 1.6 D(mm) 22.4 22.4 22.4 22.4 Number of grooves 0 1 3 3 Diffraction increment caused by the shell (%) 25% 9% -69% -68% Table I

According to the experimental data in the above table, the shell of the ultrasonic sensor module does cause diffraction and affects the detection result of the ultrasonic sensor module. Moreover, although the formation of grooves on the shell can improve the diffraction problem, compared with the improvement effect of the control sample 2 (the corresponding m value of the groove width is 2.01), it is formed according to the groove width set in this case The grooves (namely sample one and sample two) can significantly improve the improvement of diffraction problems.

In addition, the ultrasonic sensor module of this case can be designed in different sizes or specifications according to requirements. In one embodiment, if the distance from the center of the first opening 123 to the center of the second opening 124 is large, it is also That is, when the value of D in the table is larger, the value of n can be increased accordingly. In one embodiment, if the size of the ultrasonic sensor module is limited by the fact that the value of D cannot be too large, that is, when the value of w needs to be reduced, the value of m can be increased.

The sixth figure is a three-dimensional schematic diagram of the second embodiment of the ultrasonic sensor module 200 in this case. Different from the ultrasonic sensor module 100 in the first figure, the length of the grooves 125a, 125b, 125c is approximately the same as the diameter of the first opening 123 or the second opening 124. The ultrasonic sensor module 200 of this embodiment The grooves 225a, 225b, and 225c extend to the edge of the first surface 221 to ensure that the sound waves diffracted by the ultrasonic transmitting unit 140 to the surface of the housing 220 will pass through the grooves 225a, 225b, and 225c to reduce its strength. Will be transmitted to the ultrasonic receiving unit 160. However, it is not limited to this. In one embodiment, the length of the grooves 125a, 125b, 125c is greater than 1/2 the width of the first opening 123 or the second opening 124, which can effectively reduce the diffracted sound waves.

The seventh figure is a three-dimensional schematic diagram of the third embodiment of the ultrasonic sensor module 300 in this case. Different from the ultrasonic sensor module 100 in the first figure, the three grooves 125a, 125b, 125c have the same length. The three grooves 325a, 325b, 325c of the ultrasonic sensor module 300 of this embodiment It adopts a design method with different lengths. As shown in the seventh figure, the length of the two grooves 325a, 325c near the first opening 123 and the second opening 124 is shorter, and the length of the groove 325b in the middle is longer to match the sound wave from the first opening. The trajectory of 123 spreading outward to the second opening 124 effectively covers the range of sound waves diffracted by the ultrasonic transmitter 140 to the surface of the housing 320.

The eighth figure is a three-dimensional schematic diagram of the fourth embodiment of the ultrasonic sensor module 400 in this case. Different from the ultrasonic sensor module 100 in the first figure, three grooves 125a, 125b, 125c are provided on the housing 120, and only one groove 425 is provided on the housing 420 of this embodiment. This embodiment can be applied to situations where the housing 420 has a small size or the distance between the first opening 123 and the second opening 124 is small.

The ninth figure is a three-dimensional schematic diagram of the fifth embodiment of the ultrasonic sensor module 500 in this case. Different from the ultrasonic sensor module 100 in the first figure, the three grooves 125a, 125b, 125c extend along the linear direction D1. The grooves 525a, 525b, 525c of the ultrasonic sensor module 500 of this embodiment It extends along the arc direction D2.

In one embodiment, the length of the grooves 525a, 525b, 525c is greater than 1/2 of the width of the first opening 123 or the second opening 124, and the radius of curvature of the arc direction D2 is greater than the first opening 123 or the second opening The width of 124 is 1/2 to ensure that these grooves 525a, 525b, 525c can effectively cover the range of sound waves diffracted by the ultrasonic transmitter 140 to the surface of the housing 520.

In an embodiment, as shown in the ninth figure, the bending directions of the grooves 525a, 525b, and 525c are all toward the first opening 123. But it is not limited to this. In other embodiments, the groove 525a near the first opening 123 may be bent toward the first opening 123, the groove 525b near the second opening 124 may be curved toward the second opening 124, and the groove located in the middle The 525b can be curved toward the first opening 123 or the second opening 124, and can also be a linear groove 125b as shown in the first figure.

In summary, there is at least one groove between the first opening and the second opening of the housing of the ultrasonic sensor module of this case. The groove has a specific width. The sound waves will be reflected back and forth in this groove to reduce their intensity. In this way, the sound waves diffracted from the ultrasonic transmitter unit to the ultrasonic receiver unit can be effectively eliminated, and the ultrasonic sensor can avoid misjudgment.

The above are only preferred embodiments of this case, and do not impose any restriction on this case. Any person in the technical field who makes any form of equivalent substitution or modification to the technical means and technical content disclosed in this case within the scope of the technical means of this case is not deviated from the technical means of this case. It still falls within the scope of protection of this case.

100, 200, 300, 400, 500: Ultrasonic sensor module 120, 220, 320, 420, 520: shell 140: Ultrasonic transmitter unit 160: Ultrasonic receiver unit 121, 221: the first surface 122: second surface 123: First opening 124: second opening 125a, 125b, 125c, 225a, 225b, 225c, 325a, 325b, 325c, 425, 525a, 525b, 525c: groove 170: Interval layer 180: Connector w: width LM: Midline g: separation distance 1222: connection structure D1: straight line direction D2: Arc direction

The first figure is a three-dimensional schematic diagram of the first embodiment of the ultrasonic sensor module in this case; The second to fourth figures are corresponding to one of the front view, side view and top view of the ultrasonic sensor module; The fifth figure is a schematic cross-sectional view corresponding to the A-A section in the third figure; Figure 6 is a three-dimensional schematic diagram of the second embodiment of the ultrasonic sensor module in this case; The seventh figure is a three-dimensional schematic diagram of the third embodiment of the ultrasonic sensor module in this case; Figure 8 is a three-dimensional schematic diagram of the fourth embodiment of the ultrasonic sensor module in this case; and The ninth figure is a three-dimensional schematic diagram of the fifth embodiment of the ultrasonic sensor module in this case.

100: Ultrasonic sensor module

120: shell

140: Ultrasonic transmitter unit

160: Ultrasonic receiver unit

121: first surface

122: second surface

123: First opening

124: second opening

125a, 125b, 125c: groove

180: Connector

1222: connection structure

Claims (10)

An ultrasonic sensor module, including: A housing including a first surface, the first surface including a first opening, a second opening, and at least one groove, the at least one groove being located between the first opening and the second opening; An ultrasonic transmitting unit, which is arranged in the casing and emits a sound wave through the first opening; An ultrasonic receiving unit arranged in the casing and receiving the sound wave through the second opening; Wherein, the groove has a width, and the width satisfies the following formula: w = L (n + 1/m); Wherein, w is the width, n is an integer greater than or equal to zero, L is the wavelength of the sound wave emitted by the ultrasonic emitting unit, and m is a value between 3-16. The ultrasonic sensor module according to claim 1, wherein the housing further includes a second surface, and the second surface includes a plurality of connection structures arranged in an array. The ultrasonic sensor module according to claim 2, wherein the second surface and the first surface are located on opposite sides of the casing. The ultrasonic sensor module according to claim 1, wherein the length of the groove is greater than 1/2 of the width of the first opening. The ultrasonic sensor module according to claim 1, wherein the groove extends along a straight line. The ultrasonic sensor module according to claim 1, wherein the first opening is circular, and the second opening is circular. The ultrasonic sensor module according to claim 6, wherein the groove extends along an arc direction, and the radius of curvature of the arc direction is greater than the radius of the first opening or the second opening. The ultrasonic sensor module according to claim 6, wherein the length of the groove is greater than 1/2 of the width of the first opening. The ultrasonic sensor module according to claim 1, wherein the number of the grooves is plural, and the grooves are arranged parallel to each other between the first opening and the second opening. The ultrasonic sensor module according to claim 9, wherein the distance between the grooves is greater than or equal to the width.

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