CN102645654A - Distance detection device and method - Google Patents

Abstract

The invention discloses a distance detection device and a method, which are used for detecting a distance to be detected of an object. The emitter is used for emitting light along the emitting direction. The first receiver is disposed at one side of the emitter and has a first light incident surface for receiving light reflected by the object to generate a first electrical signal. The second receiver is arranged between the emitter and the first receiver and provided with a second light incident surface for receiving light reflected by the object to generate a second electric signal, wherein the first receiver is provided with a first electric signal-distance curve, the second receiver is provided with a second electric signal-distance curve, the first electric signal-distance curve is provided with a first peak, the second electric signal-distance curve is provided with a second peak, and the distance corresponding to the first peak is greater than the distance corresponding to the second peak. The invention determines whether the object is positioned in the preset distance or not through the magnitude relation of the two electric signals, thereby effectively improving the distance measuring accuracy.

Description

Distance detection device and method

technical field

The present invention relates to a distance detection device and method; specifically, the present invention relates to a short-distance detection device and method.

Background technique

With the rapid development of science and technology, various instruments with measuring distance function are constantly being introduced. From the most primitive measuring tape to various electronic range finders, these instruments meet the needs of different fields to achieve the purpose of distance measurement. Among them, the electronic ranging method includes electromagnetic ranging and photoelectric ranging. Among the distance measuring instruments mainly based on photoelectric distance measuring methods, the more popular ones are at least infrared distance measuring instruments, laser distance measuring instruments and ultrasonic sensors. Laser range finders and ultrasonic sensors have sensitive range accuracy, but are expensive. Although infrared range finders are cheaper, their range accuracy is not as good as laser range finders and ultrasonic sensors.

Generally speaking, a traditional infrared range finder includes a transmitter and a receiver. When the transmitter generates infrared rays and emits them to the object, the receiver receives the light reflected from the object to generate an electrical signal. Since the traditional infrared range finder has only one receiver, its electrical signal needs to be compared with a fixed reference electrical signal to determine the distance between the infrared range finder and the object. In addition, the material of the object will directly affect the strength of the reflected light. If the material of the object is a material that easily absorbs light, the reflected light is too weak, and the generated electrical signal is also weakened, which affects the measurement accuracy, or even cannot be compared with the reference electrical signal, and the distance cannot be measured.

Contents of the invention

An object of the present invention is to provide a distance detection device and method, which uses the curve of the electrical signal and the distance to determine the predetermined minimum distance to be measured.

Another object of the present invention is to provide a distance detection device and method, which utilizes two receivers to improve measurement accuracy in a way that is not affected by reflective materials.

Yet another object of the present invention is to provide a distance detection device and method, which can accurately perform short-distance measurement by adjusting the angle and/or position between the receiver and the transmitter.

The distance detecting device of the present invention is used for detecting the distance to be measured to an object. The distance detection device includes a transmitter, a first receiver and a second receiver. Emitters are used to emit light along the emission direction. The first receiver is arranged on one side of the transmitter and has a first light-incident surface for receiving light reflected by an object to generate a first electrical signal. The second receiver is arranged between the emitter and the first receiver and has a second light incident surface for receiving light reflected by the object to generate a second electrical signal. Wherein, the first receiver has a first electrical signal-distance curve, the second receiver has a second electrical signal-distance curve, and the first electrical signal-distance curve has a first peak, and the second electrical signal-distance curve has a second For two peaks, the distance corresponding to the first peak is greater than the distance corresponding to the second peak.

It should be noted that the distance corresponding to the intersection of the first electrical signal-distance curve and the second electrical signal-distance curve is substantially a predetermined distance. When the distance to be measured is less than the predetermined distance, the second electric signal is greater than the first electric signal, and when the distance to be measured is greater than the predetermined distance, the second electric signal is smaller than the first electric signal.

In one embodiment, the emitter has a light-emitting surface to provide light output, the normal direction of the first light-incident surface and the normal direction of the light-emitting surface of the emitter have a first angle, and the normal of the second light-incidence surface There is a second angle between the direction and the normal direction of the first light incident surface, and the first angle and the second angle are set according to a predetermined distance.

The distance detection method of the present invention is used to detect the distance to be measured to an object. The method includes: providing a distance detection device, including a transmitter, a first receiver, and a second receiver, wherein the first receiver and the second receiver The transmitter is arranged on one side of the transmitter, the first receiver has a first electrical signal-distance curve, the second receiver has a second electrical signal-distance curve, and the first electrical signal-distance curve has a first peak, and the second The electrical signal-distance curve has a second peak, and the distance corresponding to the first peak is greater than the distance corresponding to the second peak; the transmitter emits light along the emission direction; the first receiver and the second receiver receive the light reflected by the object to generate the first electrical signal and the second electrical signal; and obtaining the distance to be measured of the object or determining whether the object is within a predetermined distance according to the first electrical signal and the second electrical signal.

Specifically, the distance corresponding to the intersection point of the first electrical signal-distance curve and the second electrical signal-distance curve is substantially a predetermined distance, wherein when the distance to be measured is less than the predetermined distance, the second electrical signal is greater than the first electrical signal, and When the distance to be measured is greater than the predetermined distance, the second electrical signal is smaller than the first electrical signal.

Compared with the prior art, the distance detection device and method proposed by the present invention generate corresponding first electrical signals and second electrical signals through the first receiver and the second receiver, which can not only detect the distance between the object and The distance can further utilize the magnitude relationship between the first electrical signal and the second electrical signal to determine whether the object is within the predetermined distance, thereby improving the distance accuracy. In addition, the distance detecting device of the present invention can determine whether an object is within a predetermined distance through the relationship between the magnitudes of the electrical signals of the two receivers, not only not being affected by reflective materials but also effectively improving the distance accuracy.

Therefore, the present invention proposes a distance detection device and method that can improve the distance accuracy and is not affected by reflective materials.

The advantages and spirit of the present invention can be further understood by using the following detailed description of the invention and the accompanying drawings.

Description of drawings

Figure 1 shows a top view of an embodiment of a distance detection device;

Fig. 2 shows the electric signal-distance curve diagram of the first receiver and the second receiver;

Fig. 3 shows the electrical signal-distance curve diagram of the first object and the second object detected by the distance detection device;

FIG. 4 is a flow chart of the distance detection method of the present invention.

Detailed ways

According to a specific embodiment of the present invention, a distance detection device is provided. In this embodiment, the distance detecting device is capable of detecting the measured distance to the object and determining whether the object is within a predetermined distance. In one embodiment, the distance detection device and method of the present invention are applied to short-distance measurement, but not limited thereto.

Please refer to FIG. 1 , which is a top view of an embodiment of a distance detection device 1 . In fact, the shape of the distance detection device 1 can be determined according to the actual requirements of the product, and can be square, oblate or other different shapes, and is not limited to the embodiment shown.

As shown in FIG. 1 , the distance detection device 1 includes a transmitter 10 , a first receiver 20 and a second receiver 30 . The first receiver 20 is disposed on one side of the transmitter 10 and has a first light incident surface 25 ; the second receiver 30 is disposed between the transmitter 10 and the first receiver 20 and has a second light incident surface 35 . The emitter 10 has a light-emitting surface 15 for emitting light, and the emitter 10 emits light toward the object 2 along the emitting direction. In practical applications, the emitter 10 is preferably an invisible light, but not limited thereto. In this embodiment, the emitter is infrared. The first receiver 20 is used to receive the light reflected by the object 2 to generate a first electrical signal, and the second receiver 30 is used to receive the light reflected by the object 2 to generate a second electrical signal. That is, the first receiver 20 and the second receiver 30 are used to receive the light emitted from the transmitter 10 towards the object 2 and reflected by the object 2, and respectively generate a first electrical signal and a second electrical signal corresponding to the energy of the received light. Two electrical signals.

Specifically, the first receiver 20 has a first electrical signal-distance curve S1, the second receiver 30 has a second electrical signal-distance curve S2, and the first electrical signal-distance curve S1 has a first peak P1, and the second receiver 30 has a second electrical signal-distance curve S2. The second electrical signal-distance curve S2 has a second peak P2, and the distance d1 corresponding to the first peak P1 is greater than the distance d2 corresponding to the second peak P2, as shown in FIG. 2 . It can be seen from Figure 2 that the distance corresponding to the intersection of the first electrical signal-distance curve S1 and the second electrical signal-distance curve S2 is substantially a predetermined distance ds, and when the distance to be measured is less than the predetermined distance ds, the second electrical signal is greater than the first When the distance to be measured is greater than the predetermined distance ds, the second electrical signal is smaller than the first electrical signal. The first electrical signal-distance curve S1, the second electrical signal-distance curve S2, and the relationship between the predetermined distance and the first electrical signal and the second electrical signal will be described in detail later.

As shown in FIG. 1 , there is a first angle A1 between the normal direction of the first light incident surface 25 of the first receiver 20 and the normal direction of the light exit surface 15 of the emitter 10 . Similarly, there is a second angle A2 between the normal direction of the second light incident surface 35 of the second receiver 30 and the normal direction of the first light incident surface 25 of the first receiver 20 . In addition, the first receiver 20 and the transmitter 10 are separated from the second receiver 30 by a first distance D1 and a second distance D2 respectively.

It should be noted that the first distance D1 and the second distance D2 and the first angle A1 and the second angle A2 are selected so that the distance detection device 1 can determine whether the object 2 is located at within a predetermined distance.

Specifically, adjust the relative position and angle of the first receiver 20, the second receiver 30 and the transmitter 10, so that when the object 2 is at a predetermined distance, the first receiver 20 and the second receiver 30 correspond to the reflection of the object 2 The magnitudes of the first electrical signal and the second electrical signal obtained by the light energy are the same. In this embodiment, the predetermined distance is 5 cm, and the first electrical signal and the second electrical signal are analog voltages, but not limited thereto. In practical applications, the first distance D1 is between 8mm and 10mm, preferably 9mm; the second distance D2 is between 13mm and 15mm, preferably 14mm. In addition, the first angle A1 is between 6° and 8°, preferably 7°; and the second angle A2 is between 1° and 3°, preferably 2°.

Please refer to FIG. 2 . FIG. 2 is a graph showing electrical signal-distance curves of the first receiver 20 and the second receiver 30 . That is, by adjusting the angle and position of the receiver, a unique relationship between object distance and electrical signal will be obtained. As shown in FIG. 2 , under the condition of the above-mentioned preset relative position, the first angle A1 and the second angle A2 are selected so that the first receiver 20 and the second receiver 30 respectively have the first electric signal-distance of different peaks The curve S1 and the second electrical signal-distance curve S2, wherein the first electrical signal-distance curve S1 and the second electrical signal-distance curve S2 intersect at an intersection point, and the distance corresponding to the intersection point is substantially a predetermined distance. For example, in this embodiment, the first angle A1 is between 6° and 8°, preferably 7°; and the second angle A2 is between 1° and 3°, preferably 2°.

As shown in FIG. 2 , at a distance of 0.5 cm, the second electrical signal is greater than the first electrical signal. When the distance is increased from 0.5cm to 1.5cm, the first electrical signal increases slowly, while the second electrical signal increases rapidly. Although the distance is far away, because the position of the second receiver 30 is closer to the transmitter 10 than the first receiver 20, there will be more reflected light entering the second receiver 30 at this distance, so the change of the electrical signal-distance curve more obvious. When the distance was increased from 1.5cm to 3.5cm, the first electrical signal continued to increase slowly, while the second electrical signal decreased rapidly. This is due to the relationship between the reflection angle and the distance, so that the first receiver 20 receives more and more reflected light, while the reflected light entering the second receiver 30 becomes less and less.

When the distance increases from 3.5 cm to 5 cm, the reflected light entering the first receiver 20 and the second receiver 30 becomes less and less, so that the first electrical signal and the second electrical signal gradually become smaller. However, since the first electrical signal decreases slower than the second electrical signal, the two curves intersect at a distance of 5 cm, where 5 cm is the predetermined distance. When the distance continues to extend from 5cm to 10cm, the first electrical signal and the second electrical signal continue to decrease slowly, and the variation range of the second electrical signal is greater than the variation range of the first electrical signal, so that the second electrical signal is smaller than the first electric signal.

It is worth noting that, therefore, based on the above conditions, when the object 2 is located within a predetermined distance (eg 5cm), the second electrical signal is greater than or equal to the first electrical signal; when the object 2 is located outside the predetermined distance (eg 5cm), the second electrical signal The second electrical signal is smaller than the first electrical signal. Therefore, the distance detecting device 1 can determine whether the object 2 is within a predetermined distance by using the first electrical signal, the second electrical signal, the first electrical signal-distance curve, and the second electrical signal-distance curve. In other words, the user can set the shortest distance to be measured as a predetermined distance, and adjust the relative angles and/or positions of the transmitter 10, the first receiver 20, and the second receiver 30 according to the predetermined distance, and then The first electrical signal-distance curve S1 and the second electrical signal-distance curve S2 are obtained, wherein the intersection point of the first electrical signal-distance curve S1 and the second electrical signal-distance curve S2 is a predetermined distance (5 cm in this example). Therefore, when the distance detection device 1 performs measurement, it can determine whether the object is within the predetermined distance according to the magnitude relationship between the first electrical signal and the second electrical signal. In addition, the distance detection device 1 can not only accurately determine whether the object 2 is within a predetermined distance, but also use the electrical signal generated by the first receiver 20 and/or the second receiver 30 in response to the light signal reflected by the object 2 to directly detect The distance to be measured.

Please refer to FIG. 3 . FIG. 3 is a graph showing electrical signal-distance curves of the distance detection device 1 for different objects (such as a first object and a second object). In this embodiment, the materials of the first object and the second object are different, that is, the first object and the second object have different absorption degrees to the light emitted by the emitter 10 . For example, the first object is a wooden board, and the second object is black paper. As shown in Figure 3, since the second object (i.e. black paper) has a lower reflectivity than the first object (i.e. wood board), the first electrical signal and the second electrical signal corresponding to the second object are more corresponding The first electrical signal and the second electrical signal of the first object are weak.

As shown in FIG. 3, in this embodiment, the predetermined distance is 5 cm. That is, for the first object and the second object, the first receiver 20 and the second receiver 30 respectively have the first electrical signal-distance curve S11 and the second electrical signal-distance curve S12 corresponding to the first object, and the corresponding The first electrical signal-distance curve S21 and the second electrical signal-distance curve S22 of the second object. As shown in FIG. 3 , although the electrical signal strengths of the first receiver 20 and the second receiver 30 for the first object and the second object are different under the aforementioned relative angle and position conditions, they have similar trends. That is, as shown in FIG. 3, the intersection point of the first electrical signal-distance curve S11 corresponding to the first object and the second electrical signal-distance curve S12, and the first electrical signal-distance curve S21 corresponding to the second object and the second The intersection points of the two electrical signal-distance curves S22 are located at a distance of about 5 cm. Specifically, within a predetermined distance (for example, 5cm), whether it is the first electrical signal of the first electrical signal-distance curve S11 or the first electrical signal-distance curve S21, the first electrical signal is smaller than the second electrical signal-distance curve S12 or the second electrical signal. The corresponding second electrical signal of the signal-distance curve S22; and outside a predetermined distance (for example, 5cm), whether it is the first electrical signal-distance curve S11 or the first electrical signal-distance curve S21, the first electrical signal is greater than the second electrical signal The electrical signal-distance curve S12 or the corresponding second electrical signal of the second electrical signal-distance curve S22. Therefore, for the detection of different objects by the distance detection device 1 of the present invention, even if the material of the objects is different (that is, the reflection effect is different), the distance detection device 1 still maintains a relatively good distance measurement accuracy. Therefore, the distance detection device 1 of the present invention can determine whether an object is located within a predetermined distance through the magnitude relationship of the electrical signals of the two receivers, which not only can effectively improve the distance accuracy but is not affected by reflective materials.

FIG. 4 is a flow chart of the distance detection method of the present invention. The distance detection method includes step 1010, providing a distance detection device, which includes a transmitter, a first receiver, and a second receiver, wherein the first receiver and the second receiver are arranged on one side of the transmitter, and the first receiver The receiver has a first electrical signal-distance curve, the second receiver has a second electrical signal-distance curve, and the first electrical signal-distance curve has a first peak, the second electrical signal-distance curve has a second peak, and the first The distance corresponding to the peak is greater than the distance corresponding to the second peak. The distance detection device provided here may be as shown in FIG. 1 , wherein the second receiver is disposed between the first receiver and the transmitter, but not limited thereto. In addition, as mentioned above, the positions and angles of the first receiver and the second receiver relative to the transmitter can be adjusted so that they have the required first electrical signal-distance curve and the second electrical signal-distance curve respectively. .

Step 1020 includes the emitter emitting light along the emission direction. For example, an infrared emitter can be used as the emitter of the present invention to emit infrared rays in the direction of an object.

Step 1030 includes the first receiver and the second receiver receiving light reflected by the object to generate a first electrical signal and a second electrical signal respectively. For example, the first receiver and the second receiver receive the infrared rays reflected by the object, and respectively generate corresponding electrical signals in response to the energy of the infrared rays.

Step 1040 includes obtaining the distance to be measured of the object or determining whether the object is within a predetermined distance according to the relationship between the first electrical signal and the second electrical signal, where the intersection point of the first electrical signal-distance curve and the second electrical signal-distance curve corresponds to The distance of is essentially a predetermined distance. The predetermined distance mentioned here refers to the shortest distance that the user wants to measure, for example, 5 cm, but it is not limited thereto, and may vary according to actual applications and user needs. Step 1041 includes when the distance to be measured is less than the predetermined distance, the second electrical signal is greater than the first electrical signal; step 1042 includes when the distance to be measured is greater than the predetermined distance, the second electrical signal is smaller than the first electrical signal.

Compared with the prior art, the distance detection device and method proposed by the present invention can not only detect the distance to the object, but also can use the electric signal-distance curve to set the required predetermined distance, through the first receiver and the second The receiver is used to generate a corresponding first electrical signal and a second electrical signal, and determine whether the object is within a predetermined distance according to the magnitude relationship between the first electrical signal and the second electrical signal, thereby improving the distance accuracy. Because the traditional distance detection device only has a transmitter and a receiver, the electrical signal of the receiver can only be compared with the reference electrical signal, and the measurement effect obtained is limited, and the short-distance measurement is even more insufficient. Therefore, the distance detection device of the present invention can not only detect the distance to the object, but also determine whether the object is within the predetermined distance through the relationship between the electrical signals of the two receivers. Affected by reflective materials.

With the above detailed description of the preferred embodiments, it is hoped that the features and spirit of the present invention can be described more clearly, and the scope of the present invention is not limited by the preferred embodiments disclosed above. On the contrary, the intention is to cover various modifications and equivalent arrangements within the scope of the appended claims of the present invention.

Claims (10)

1. A distance detection device for detecting the distance to be measured to an object, characterized in that, the above-mentioned distance detection device comprises: Emitters for emitting light along the emission direction; The first receiver is arranged on one side of the above-mentioned transmitter and has a first light-incident surface for receiving light reflected by the above-mentioned object to generate a first electrical signal; and The second receiver is arranged between the above-mentioned transmitter and the above-mentioned first receiver and has a second light-incident surface for receiving light reflected by the above-mentioned object to generate a second electrical signal, Wherein, the above-mentioned first receiver has a first electric signal-distance curve, the above-mentioned second receiver has a second electric signal-distance curve, and the above-mentioned first electric signal-distance curve has a first peak, and the above-mentioned second electric signal- The distance curve has a second peak, and the distance corresponding to the first peak is greater than the distance corresponding to the second peak. 2 . The distance detection device according to claim 1 , wherein the distance corresponding to the intersection of the first electrical signal-distance curve and the second electrical signal-distance curve is a predetermined distance. 3. The distance detection device according to claim 2, characterized in that, when the distance to be measured is less than the predetermined distance, the second electrical signal is greater than the first electrical signal, and when the distance to be measured is greater than the predetermined distance, the The second electrical signal is smaller than the above-mentioned first electrical signal. 4. The distance detection device according to claim 2, characterized in that, there is a first angle between the normal direction of the first light incident surface and the normal direction of the light exit surface of the above-mentioned emitter, and the second light incident surface There is a second angle between the normal direction of the surface and the normal direction of the first light incident surface, and the first angle and the second angle are set according to the predetermined distance. 5 . The distance detection device according to claim 4 , wherein the first angle is between 6° and 8°, and the second angle is between 1° and 3°. 6. The distance detecting device according to claim 2, characterized in that, the midpoint of the first light-incident surface is a first distance away from the midpoint of the second light-incident surface, and the midpoint of the second light-incident surface There is a second distance away from the midpoint of the emitter, and the first distance and the second distance are set according to the predetermined distance. 7 . The distance detecting device according to claim 6 , wherein the first distance is between 8 mm and 10 mm, and the second distance is between 13 mm and 15 mm. 8. The distance detecting device according to claim 1, characterized in that, the above-mentioned emitter is an infrared light emitter. 9. A distance detection method for detecting the distance to be measured to an object, characterized in that the above-mentioned distance detection method comprises: A distance detection device is provided, including a transmitter, a first receiver, and a second receiver, wherein the first receiver and the second receiver are arranged on one side of the transmitter, and the first receiver has a first electrical signal - a distance curve, the second receiver has a second electrical signal-distance curve, and the first electrical signal-distance curve has a first peak, the second electrical signal-distance curve has a second peak, and the first peak corresponds to The distance is greater than the distance corresponding to the second peak above; The emitter emits light along the emitting direction; The first receiver and the second receiver receive light reflected by the object to generate a first electrical signal and a second electrical signal respectively; and Obtaining the distance to be measured of the object or determining whether the object is within a predetermined distance according to the first electrical signal and the second electrical signal. 10. The distance detection method according to claim 9, wherein the distance corresponding to the intersection point of the first electrical signal-distance curve and the second electrical signal-distance curve is the predetermined distance, and the distance to be measured is less than When the predetermined distance is reached, the second electrical signal is greater than the first electrical signal, and when the distance to be measured is greater than the predetermined distance, the second electrical signal is smaller than the first electrical signal.

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