JP2021038977A - Ultrasonic sensor - Google Patents

Abstract

To provide an ultrasonic sensor that can accurately determine the height of an object.SOLUTION: An ultrasonic sensor is mounted on a vehicle. The ultrasonic sensor includes a transmission unit, a reception unit, a peak detection unit, and a height determination unit. The transmission unit transmits ultrasonic waves. The reception unit receives a reflected wave. The peak detection unit executes a peak detection process in the reflected wave for detecting (1) a first peak whose reflected wave intensity is larger than a first threshold value and (2) a second peak whose reflected wave intensity is greater than a second threshold value and less than the first threshold value and whose detection time is earlier than the detection time of the first peak and within a predetermined set time from the detection time of the first peak. The height determination unit determines the height of an object based on the detection result of the peak detection unit.SELECTED DRAWING: Figure 1

Description

The present disclosure relates to ultrasonic sensors.

Patent Document 1 discloses an ultrasonic sensor. The ultrasonic sensor transmits ultrasonic waves. In addition, the ultrasonic sensor receives the reflected wave generated by the ultrasonic wave reflected by the object. When the object is taller than the position of the ultrasonic sensor, the peak of the reflected wave having an intensity exceeding the threshold value occurs twice within a certain time. The first peak is the peak of the reflected wave reflected at the portion of the object at the same height as the ultrasonic sensor. The second peak is the peak of the reflected wave reflected at the base of the object. When the peak of the reflected wave having an intensity exceeding the threshold occurs twice within a certain time, the ultrasonic sensor determines that the object is taller than the position of the ultrasonic sensor.

When the object is shorter than the position of the ultrasonic sensor, the peak of the reflected wave having an intensity exceeding the threshold value occurs only once. The one-time peak of intensity above the threshold is the peak of the reflected wave reflected at the root of the object. When the peak of the reflected wave having an intensity exceeding the threshold occurs only once, the ultrasonic sensor determines that the object is shorter than the position of the ultrasonic sensor.

Japanese Patent No. 5846316

For example, objects such as guardrails and other vehicles are tall and have a gap between them and the road surface. When ultrasonic waves are transmitted to an object such as a guardrail or another vehicle, reflection at the root does not occur. Therefore, when ultrasonic waves are transmitted to an object such as a guard rail or another vehicle, only the peak of the reflected wave reflected at the same height as the ultrasonic sensor is generated, and the peak of the reflected wave reflected at the root of the object is generated. Does not occur. That is, in the case of an object such as a guardrail or another vehicle, even if the object is taller than the position of the ultrasonic sensor, the peak of the reflected wave having an intensity exceeding the threshold occurs only once.

The ultrasonic sensor described in Patent Document 1 determines that an object such as a guard rail or another vehicle is an object shorter than the position of the ultrasonic sensor. Therefore, the ultrasonic sensor described in Patent Document 1 cannot accurately determine the height of the object. One aspect of the present disclosure is to provide an ultrasonic sensor capable of accurately determining the height of an object.

One aspect of the present disclosure is an ultrasonic sensor mounted on a vehicle, which receives a transmission unit configured to transmit ultrasonic waves and a reflected wave generated by the ultrasonic waves reflected by an object. In the receiving unit configured as described above, in the reflected wave, (1) the first peak whose reflected wave intensity is larger than the first threshold value, and (2) the reflected wave intensity is larger than the second threshold value and less than the first threshold value. The peak detection process is configured to detect the second peak whose detection time is earlier than the detection time of the first peak and is within a predetermined set time from the detection time of the first peak. An ultrasonic wave having a peak detection unit and a height determination unit configured to determine the height of the object based on the detection result of the peak detection unit, and the second threshold value is smaller than the first threshold value. It is a sensor. The ultrasonic sensor, which is one aspect of the present disclosure, can accurately determine the height of an object.

Another aspect of the present disclosure is an ultrasonic sensor mounted on a vehicle, which receives a transmission unit configured to transmit ultrasonic waves and a reflected wave generated by the ultrasonic waves reflected by an object. In the receiving unit configured as described above, in the reflected wave, (1) the first peak whose reflected wave intensity is larger than the first threshold value, and (2) the reflected wave intensity is larger than the second threshold value smaller than the first threshold value. A peak detection process for detecting a second peak that is less than the first threshold value, has a detection time earlier than the detection time of the first peak, and is within a predetermined set time from the detection time of the first peak. The height of the object is determined from the peak detection unit configured to perform the above, the detection time of the first peak, the detection time of the second peak, and the distances of the transmission unit and the reception unit from the road surface. It is an ultrasonic sensor including an object height calculation unit configured to calculate. The ultrasonic sensor, which is one aspect of the present disclosure, can calculate the height of an object.

It is a block diagram which shows the structure of an ultrasonic sensor 1. It is a block diagram which shows the functional structure of the control part 3. It is a flowchart which shows the process which the ultrasonic sensor 1 executes. It is explanatory drawing which shows the 1st peak P1 and the 2nd peak P2. It is explanatory drawing which shows the method of calculating the distance D2. It is explanatory drawing which shows the reflected wave corresponding to a high obstacle. It is explanatory drawing which shows the method of calculating the height H of an obstacle 25. It is explanatory drawing which shows the reflected wave corresponding to the high obstacle which does not have a root part 29. It is explanatory drawing which shows the reflected wave corresponding to the high obstacle with the root part 29. It is explanatory drawing which shows the example that the 1st threshold value TH1 and the 2nd threshold value TH2 change with the lapse of time. It is explanatory drawing which shows another method of determining the height of an obstacle.

An exemplary embodiment of the present disclosure will be described with reference to the drawings.
<First Embodiment>
1. 1. Configuration of Ultrasonic Sensor 1 The configuration of the ultrasonic sensor 1 will be described with reference to FIGS. 1, 2, and 4. The ultrasonic sensor 1 is mounted on the vehicle. The ultrasonic sensor 1 is attached to, for example, a rear end portion, a front end portion, or the like of a vehicle. As shown in FIG. 1, the ultrasonic sensor 1 includes a control unit 3, a transmission unit 5, and a reception unit 7.

The control unit 3 includes a microcomputer having a CPU 9 and, for example, a semiconductor memory such as a RAM or a ROM (hereinafter referred to as a memory 11).
Each function of the control unit 3 is realized by the CPU 9 executing a program stored in a non-transitional substantive recording medium. In this example, the memory 11 corresponds to a non-transitional substantive recording medium in which a program is stored. Moreover, when this program is executed, the method corresponding to the program is executed. The control unit 3 may include one microcomputer or a plurality of microcomputers.

As shown in FIG. 2, the control unit 3 includes a transmission instruction unit 12, a peak detection unit 13, a height determination unit 15, a type determination unit 17, a set time calculation unit 19, and an object height calculation unit 21. And a distance calculation unit 23.

The transmission unit 5 transmits ultrasonic waves. The ultrasonic waves transmitted by the transmission unit 5 are reflected by an object to generate reflected waves. The receiving unit 7 receives the reflection. The transmitting unit 5 and the receiving unit 7 are attached to the vehicle 24 as shown in FIG. The transmitting unit 5 and the receiving unit 7 may be integrated.

2. Processing executed by the ultrasonic sensor 1 The processing executed by the ultrasonic sensor 1 will be described with reference to FIGS. 3 to 9. In step 1 of FIG. 3, the transmission instruction unit 12 transmits ultrasonic waves using the transmission unit 5.

In step 2, the receiving unit 7 receives the reflected wave. The reflected wave to be received is generated by reflecting the ultrasonic wave transmitted in step 1 on an object.
In step 3, the peak detection unit 13 performs the peak detection process. The peak detection process is a process for detecting a peak in the reflected wave received in step 2.

In step 4, the peak detection unit 13 determines whether or not the first peak P1 is detected in the peak detection process of step 3. As shown in FIG. 4B, the first peak P1 is a peak of the reflected wave whose reflected wave intensity is larger than the first threshold value TH1.

The horizontal axis of FIG. 4B represents the time with the time at which the ultrasonic wave is transmitted as the origin. The vertical axis of FIG. 4B represents the reflected wave intensity. The same applies to FIGS. 6B, 8B, 9B, and 10 which will be described later. When the first peak P1 is detected, this process proceeds to step 5. If the first peak P1 is not detected, this process ends.

In step 5, the distance calculation unit 23 calculates the distance D2. As shown in FIG. 5, the distance D2 is the distance in the horizontal direction from the transmitting unit 5 and the receiving unit 7 to the obstacle 25. The obstacle 25 corresponds to an object. Here, it is assumed that the first peak P1 determined to be detected in step 4 is the peak of the reflected wave 31 generated by the reflection of the ultrasonic wave 27 at the root portion 29 of the obstacle 25.

The method by which the distance calculation unit 23 calculates the distance D2 is as follows. The distance calculation unit 23 calculates the time difference ΔT1 from the time when the ultrasonic wave 27 is transmitted to the detection time T1 based on the detection time T1 when the first peak P1 is detected. Here, the detection time T1 is the time when the reflected wave 31 reflected by the root portion 29 is received.

The distance calculation unit 23 calculates the linear distance D1 from the transmission unit 5 and the reception unit 7 to the root portion 29 based on the time difference ΔT1. The distance D3 from the transmitting unit 5 and the receiving unit 7 to the road surface 30 is a known value.

As shown in FIG. 5, there is a right triangle whose hypotenuse is a straight line distance D1 and whose other two sides are a distance D2 and a distance D3. The distance calculation unit 23 calculates the distance D2 based on the straight line distance D1 and the distance D3.

Returning to FIG. 3, in step 6, the distance calculation unit 23 determines whether or not the distance D2 calculated in step 5 exceeds a preset predetermined value. When the distance D2 exceeds a predetermined value, this process ends. If the distance D2 is equal to or less than a predetermined value, this process proceeds to step 7.

In step 7, the height determination unit 15 determines whether or not the reflected wave intensity of the first peak P1 determined to be detected in step 4 is greater than the third threshold value TH3. The third threshold TH3 is larger than the first threshold TH3. FIG. 6B shows an example in which the reflected wave intensity of the first peak P1 is larger than the third threshold value TH3.

As shown in FIG. 6A, when the obstacle 25 is a high obstacle, the reflected wave intensity of the first peak P1A tends to be larger than the third threshold TH3 as shown in FIG. 6B. The high obstacle is, for example, an obstacle 25 whose height is equal to or higher than a predetermined height. The predetermined height is, for example, a height at which the position of the upper end 25A of the obstacle 25 is higher than or about the same as that of the transmitting unit 5 and the receiving unit 7.

The first peak P1A is, for example, the peak of the reflected wave 31 directly above the root portion 29 and reflected at a portion having the same height as the transmitting unit 5 and the receiving unit 7 (hereinafter referred to as the equal height portion 33). is there. If the obstacle 25 is a high obstacle, the contour 33 is part of the obstacle 25.

The first peak P1B shown in FIG. 6B is the peak of the reflected wave 31 reflected by the root portion 29 of the obstacle 25. The peak PX shown in FIG. 6B is the peak of the reflected wave 31 reflected by the obstacle 35 shown in FIG. 6A. Obstacle 35 is shorter than Obstacle 25. The obstacle 35 is closer to the transmitting unit 5 and the receiving unit 7 than the obstacle 25. Even if the peak PX corresponds to the second peak P2 described later, it is not used for determining the height of the obstacle 25.

When the reflected wave intensity of the first peak P1 is larger than the third threshold value TH3, this process proceeds to step 18. When the reflected wave intensity of the first peak P1 is equal to or less than the third threshold value TH3, this process proceeds to step 8.

In step 8, the type determination unit 17 determines whether the number of first peaks P1 detected in the peak detection process of step 3 is one or two. If the number of first peaks P1 is one, this process proceeds to step 9. If the number of first peaks P1 is two, this process proceeds to step 17.

In step 9, the set time calculation unit 19 calculates the set time S as shown in FIG. 4B. The set time S is the time from the time TS to the detection time T1. The time TS is the time when the reflected wave 31 is received when it is assumed that the ultrasonic wave 27 is reflected at the equal height portion 33. The distance from the transmitting unit 5 and the receiving unit 7 to the equal height portion 33 is the distance D2. The set time calculation unit 19 can calculate the distance D2 by the method described above, and can calculate the time TS based on the distance D2. The detection time T1 is the time when the first peak P1 is detected. The time TS may be a design value input in advance.

In step 10, the peak detection unit 13 determines whether or not the second peak P2 is detected in the peak detection process of step 3.
As shown in FIG. 4B, the reflected wave intensity of the second peak P2 is larger than the second threshold TH2. The second threshold TH2 is smaller than the first threshold TH1. The reflected wave intensity of the second peak P2 is less than the first threshold TH1. The detection time T2 at which the second peak P2 is detected is earlier than the detection time T1. The detection time T2 is within the set time S from the detection time T1. The set time S is a value calculated in step 9.

As shown in FIG. 4A, the second peak P2 is detected when the obstacle 25 is a low obstacle. The low obstacle is an obstacle 25 in which the position of the upper end 25A is lower than or similar to that of the transmitting unit 5 and the receiving unit 7. The second peak P2 is the peak of the reflected wave 31 reflected at the upper end 25A.

Since the reflected intensity of the reflected wave 31 reflected at the upper end 25A is low, the reflected intensity of the second peak P2 is less than the first threshold value TH1. When the obstacle 25 is a low obstacle, the upper end 25A is closer to the transmitting unit 5 and the receiving unit 7 than the root portion 29. Therefore, the detection time T2 is earlier than the detection time T1. When the obstacle 25 is a low obstacle, the upper end 25A is farther from the transmitting unit 5 and the receiving unit 7 than the equal height portion 33. Therefore, the detection time T2 is later than the time TS. When the obstacle 25 is a low obstacle, the equal height portion 33 is located above the upper end 25A.

When the second peak P2 is detected, this process proceeds to step 11. If the second peak P2 is not detected, this process proceeds to step 16.
In step 11, it is determined that the height determination unit 15 has detected a low obstacle.

In step 12, the object height calculation unit 21 calculates the height H of the obstacle 25. The method of calculating the height H of the obstacle 25 will be described with reference to FIG.
The object height calculation unit 21 calculates the distance D2 by the method described above. The object height calculation unit 21 calculates the time difference ΔT2 from the time when the ultrasonic wave 27 is transmitted to the detection time T2 based on the detection time T2. The detection time T2 is the time when the reflected wave 31 reflected at the upper end 25A is received. The object height calculation unit 21 calculates the distance D4 from the transmission unit 5 and the reception unit 7 to the upper end 25A based on the time difference ΔT2.

As shown in FIG. 7, the distance between the upper end 25A and the transmitting unit 5 and the receiving unit 7 in the vertical direction is D5. As shown in FIG. 7, there is a right triangle whose hypotenuse is the distance D4 and the other two sides are the distance D2 and the distance D5. The object height calculation unit 21 calculates the distance D5 based on the distance D2 and the distance D4. The object height calculation unit 21 calculates the height H of the obstacle 25 by subtracting the distance D5 from the distance D3. The distance D3 is a known value.

In step 13, the type determination unit 17 determines whether or not the height H of the obstacle 25 calculated in step 12 is equal to or greater than a predetermined reference value. The reference value is set as follows. When the height H is equal to or higher than the reference value, the obstacle 25 comes into contact with the vehicle 24. When the height H is less than the reference value, the obstacle 25 does not come into contact with the vehicle 24.

If the height H is equal to or greater than the reference value, the present process proceeds to step 14. If the height H is less than the reference value, the process proceeds to step 15.
In step 14, the type determination unit 17 determines that the obstacle 25 is a vehicle contact obstacle. The vehicle contact obstacle is an obstacle 25 which is a low obstacle and has a height H sufficient to contact the vehicle 24.

In step 15, the type determination unit 17 determines that the obstacle 25 is a vehicle non-contact obstacle. The vehicle contact obstacle is an obstacle 25 that is a low obstacle and does not have a height H sufficient to contact the vehicle 24.

In step 16, the type determination unit 17 determines that the obstacle 25 is a high obstacle without the root portion 29, as shown in FIG. 8A. In the case of a high obstacle without a root portion 29, the reflected wave from the upper end 25A is not received, so that the second peak P2 is not detected as shown in FIG. 8B. Further, in the case of a high obstacle without the root portion 29, only the reflected wave 31 from the equal height portion 33 is received and the reflected wave 31 from the root portion 29 is not received, so that the first peak P1 is only one. ..

In step 17, the height determination unit 15 performs the following processing. This process will be described with reference to FIG.
As shown in FIG. 9B, the two first peaks P1 are designated as the first peaks P1A and P1B. The time when the first peak P1A is detected is defined as the detection time T1A. The time when the first peak P1B is detected is defined as the detection time T1B. The detection time T1A is earlier than the detection time T1B.

The first peak P1A is the peak of the reflected wave 31 reflected at a position above the root portion 29 shown in FIG. 9A among the obstacles 25. The first peak P1B is the peak of the reflected wave 31 reflected by the root portion 29 shown in FIG. 9A.

The height determination unit 15 calculates the time difference ΔT1B from the time when the ultrasonic wave 27 is transmitted to the detection time T1B when the reflected wave 31 reflected by the root portion 29 is received, based on the detection time T1B when the first peak P1B is detected. To do.

The height determination unit 15 calculates the linear distance D1 from the transmission unit 5 and the reception unit 7 to the root portion 29 based on the time difference ΔT1B. The distance D3 from the transmitting unit 5 and the receiving unit 7 to the road surface 30 is a known value. As shown in FIG. 9A, there is a right triangle whose hypotenuse is a straight line distance D1 and whose other two sides are a distance D2 and a distance D3. The distance calculation unit 23 calculates the distance D2 based on the straight line distance D1 and the distance D3.

The height determination unit 15 calculates the time TS for receiving the reflected wave 31 reflected at a position where the distance from the transmission unit 5 and the reception unit 7 is the distance D2. The height determination unit 15 sets a time zone having a predetermined width around the time TS as a setting range X. The setting range X is a range set with reference to the detection time T1B.

The height determination unit 15 determines whether or not the detection time T1A is within the set range X. The fact that the detection time T1A is within the set range X corresponds to the difference between the detection time T1A and the detection time T1B being within the preset range. If the detection time T1A is within the set range X, this process proceeds to step 18. If the detection time T1A is not within the set range X, this process ends.

In step 18, the height determination unit 15 determines that a high obstacle with a root portion 29, as shown in FIG. 9A, has been detected. In the case of a high obstacle with a root portion 29, the reflected wave 31 from the root portion 29 becomes the first peak P1B shown in FIG. 9B. Further, in the case of a high obstacle having a root portion 29, the reflected wave 31 from the equal height portion 33 becomes the first peak P1A. Further, in the case of a high obstacle having a root portion 29, the first peak P1A is the peak of the reflected wave 31 reflected at the position where the distance from the transmitting unit 5 and the receiving unit 7 is the distance D2 (that is, the equal height portion 33). Therefore, the detection time T1A is within the set range X.

3. 3. Effects of the ultrasonic sensor 1 (1A) The ultrasonic sensor 1 performs a peak detection process for detecting the first peak P1 and the second peak P2 in the reflected wave 31. The ultrasonic sensor 1 determines the height of the obstacle 25 by the method described above based on the result of the peak detection process. Therefore, the ultrasonic sensor 1 can accurately determine the height of the obstacle 25.

(1B) The ultrasonic sensor 1 can determine the type of the obstacle 25 based on the number of the first peak P1 and the number of the second peak P2.
(1C) When the reflected wave intensity of the first peak P1 is further larger than the third threshold value TH3, the ultrasonic sensor 1 determines that the obstacle 25 is a high obstacle. Therefore, the ultrasonic sensor 1 can determine the height of the obstacle 25 more accurately.

(1D) When two first peaks P1 are detected and the difference between the detection times of the two first peaks P1 is within a preset range, the ultrasonic sensor 1 has an obstacle 25 as a high obstacle. Judge that there is. Therefore, the ultrasonic sensor 1 can determine the height of the obstacle 25 more accurately.

(1E) The ultrasonic sensor 1 calculates the distance D2 from the detection time T1 and the distance D3. The ultrasonic sensor 1 calculates the set time S based on the distance D2. The ultrasonic sensor 1 determines the height of the obstacle 25 using the set time S. Therefore, the ultrasonic sensor 1 can determine the height of the obstacle 25 more accurately.

(1F) When the ultrasonic sensor 1 determines that the obstacle 25 is a low obstacle, the ultrasonic sensor 1 calculates the height H of the obstacle 25 from the detection time T1, the detection time T2, and the distance D3. Therefore, the ultrasonic sensor 1 can calculate the height H of a low obstacle.

(1G) The ultrasonic sensor 1 calculates the distance D2 from the detection time T1 and the distance D3. The ultrasonic sensor 1 does not determine the height H of the obstacle 25 when the distance D2 exceeds a predetermined value. When the distance D2 exceeds a predetermined value, it is less necessary to determine the height H of the obstacle 25. The ultrasonic sensor 1 can suppress the execution of less necessary processing.
<Other Embodiments>
Although the embodiments of the present disclosure have been described above, the present disclosure is not limited to the above-described embodiments, and can be implemented in various modifications.

(1) As shown in FIG. 10, the first threshold value TH1 and the second threshold value TH2 may change with the passage of time. The third threshold TH3 may also change with the passage of time.
The first threshold value TH1, the second threshold value TH2, and the third threshold value TH3 become smaller as time elapses, for example. Since the reflected wave intensity basically decreases as time elapses, when the first threshold value TH1, the second threshold value TH2, and the third threshold value TH3 decrease as time elapses, the first peak P1 and the first peak P1 and Two peaks P2 can be detected more accurately.

(2) The peak detection unit 13 can perform the peak detection process of step 3 a plurality of times. The height determination unit 15 can determine the height of the obstacle 25 based on a plurality of peak detection processes. In this case, the ultrasonic sensor 1 can determine the height of the obstacle 25 more accurately.

The height determination unit 15 can determine the height of the obstacle 25 based on the detection result having the highest frequency among the detection results of the plurality of peak detection processes. In this case, the ultrasonic sensor 1 can determine the height of the obstacle 25 more accurately.

(3) The ultrasonic sensor 1 may determine the height of an object by the method shown in FIG. The transmission unit 5 transmits high-frequency ultrasonic waves FH and low-frequency ultrasonic waves FL. The receiving unit 7 receives each reflected wave. Ultrasonic FH has higher directivity than ultrasonic FL.

The ultrasonic FH and the ultrasonic FL reach the wall 37 in the front direction Y of the transmitting unit 5 and the receiving unit 7, and a reflected wave is generated. The receiving unit 7 receives the reflected wave of the ultrasonic FH reflected by the wall 37 and the reflected wave of the ultrasonic FL reflected by the wall 37.

The ultrasonic FH hardly reaches the step 39 or the beam 41 located at a position deviating from the front direction Y, and the ultrasonic FL reaches. The receiving unit 7 hardly receives the reflected wave of the ultrasonic FH reflected by the step 39 or the beam 41. The receiving unit 7 receives the reflected wave of the ultrasonic FL reflected by the step 39 and the beam 41.

The ultrasonic sensor 1 frequency-separates the received reflected wave. When the amplitude of the reflected wave of the ultrasonic FH is smaller than the amplitude of the reflected wave of the ultrasonic FL, the detected object is deviated from the front direction Y like the step 39 and the beam 41. Judge that it is in position. The step 39 corresponds to a short object.

When the amplitude of the reflected wave of the ultrasonic FH is larger than the amplitude of the reflected wave of the ultrasonic FL, the ultrasonic sensor 1 determines that the detected object is in the front direction Y like the wall 37. The wall 37 corresponds to a tall object.
The ultrasonic sensor 1 further includes, for example, an object detection unit configured to detect an object by the method described above based on a reflected wave when two types of transmitted waves having different directivities are transmitted, and the object detection unit. When detects an object, the height determination unit 15 determines the height of the object.
The ultrasonic sensor 1 further includes, for example, an object detection unit configured to detect an object by the method described above based on a reflected wave when two types of transmitted waves having different directivities are transmitted, and the object detection unit. When the object is detected, the object height calculation unit 21 calculates the height of the object.
The two types of transmitted waves having different directivity are, for example, ultrasonic FH and ultrasonic FL. The object detected by the object detection unit is, for example, an obstacle such as a step 39.

(4) The control unit 3 and its method described in the present disclosure are dedicated provided by configuring a processor and memory programmed to perform one or more functions embodied by a computer program. It may be realized by a computer. Alternatively, the control unit 3 and its method described in the present disclosure may be realized by a dedicated computer provided by configuring the processor with one or more dedicated hardware logic circuits. Alternatively, the control unit 3 and its method described in the present disclosure are a combination of a processor and memory programmed to execute one or more functions and a processor composed of one or more hardware logic circuits. It may be realized by one or more dedicated computers configured by. The computer program may also be stored on a computer-readable non-transitional tangible recording medium as an instruction executed by the computer. The method for realizing the functions of each unit included in the control unit 3 does not necessarily include software, and all the functions may be realized by using one or a plurality of hardware.
(5) A plurality of functions possessed by one component in the above embodiment may be realized by a plurality of components, or one function possessed by one component may be realized by a plurality of components. .. Further, a plurality of functions possessed by the plurality of components may be realized by one component, or one function realized by the plurality of components may be realized by one component. Further, a part of the configuration of the above embodiment may be omitted. In addition, at least a part of the configuration of the above embodiment may be added or replaced with the configuration of the other above embodiment.

(6) In addition to the ultrasonic sensor 1 described above, a system having the ultrasonic sensor 1 as a component, a program for operating a computer as a control unit 3 of the ultrasonic sensor 1, a semiconductor memory recording this program, and the like. The present disclosure can also be realized in various forms such as a non-transitional actual recording medium, a method for determining the height of an object, a method for calculating the height of an object, and the like.

1 ... Ultrasonic sensor, 3 ... Control unit, 5 ... Transmission unit, 7 ... Reception unit, 9 ... CPU, 11 ... Memory, 12 ... Transmission instruction unit, 13 ... Peak detection unit, 15 ... Height judgment unit, 17 ... Type judgment unit, 19 ... Set time calculation unit, 21 ... Object height calculation unit, 23 ... Distance calculation unit, 25 ... Obstacle, 25A ... Top, 27 ... Ultrasonic wave, 29 ... Root, 30 ... Road surface, 31 ... Reflected wave, 33 ... iso-high part,
35 ... Obstacles, 37 ... Walls, 39 ... Steps, 41 ... Beams

Claims (14)

An ultrasonic sensor mounted on a vehicle
With a transmission unit configured to transmit ultrasonic waves,
A receiving unit configured to receive the reflected wave generated by the ultrasonic wave reflected by an object, and
In the reflected wave, (1) the first peak whose reflected wave intensity is greater than the first threshold, and (2) the reflected wave intensity is greater than the second threshold and less than the first threshold, and the detection time is the first. A peak detection unit configured to perform a peak detection process for detecting a second peak that is earlier than the detection time of one peak and within a predetermined set time from the detection time of the first peak.
A height determination unit configured to determine the height of the object based on the detection result of the peak detection unit, and
With
The second threshold value is an ultrasonic sensor smaller than the first threshold value. The ultrasonic sensor according to claim 1.
An ultrasonic sensor further comprising a type determination unit configured to determine the type of the object based on the number of the first peaks and the number of the second peaks. The ultrasonic sensor according to claim 1 or 2.
When the reflected wave intensity of the first peak is further larger than the third threshold value larger than the first threshold value, the height determination unit determines that the height of the object is equal to or higher than a predetermined height. .. The ultrasonic sensor according to claim 3.
The third threshold value is an ultrasonic sensor that changes with the passage of time. The ultrasonic sensor according to any one of claims 1 to 4.
When the peak detection unit detects two first peaks and the difference between the detection times of the two first peaks is within a preset range, the height determination unit has a height of the object. An ultrasonic sensor that determines that the height is above a specified level. The ultrasonic sensor according to any one of claims 1 to 5.
The peak detection unit is configured to perform the peak detection process a plurality of times.
The height determination unit is an ultrasonic sensor configured to determine the height of the object based on a plurality of peak detection processes. The ultrasonic sensor according to claim 6.
The height determination unit is an ultrasonic sensor configured to determine the height of the object based on the detection result having the highest frequency among the detection results of the peak detection processing a plurality of times. The ultrasonic sensor according to any one of claims 1 to 7.
The distance in the horizontal direction from the ultrasonic sensor to the object is calculated from the detection time of the first peak and the distances from the road surface of the transmission unit and the reception unit, and based on the distance in the horizontal direction, the said An ultrasonic sensor further comprising a set time calculation unit configured to calculate the set time. The ultrasonic sensor according to any one of claims 1 to 8.
The first threshold value and the second threshold value are ultrasonic sensors that change with the passage of time. The ultrasonic sensor according to any one of claims 1 to 9.
When the height determination unit determines that the height of the object is equal to or less than a predetermined height, the detection time of the first peak, the detection time of the second peak, and the transmission unit and the reception unit An ultrasonic sensor further comprising an object height calculation unit configured to calculate the height of the object from the distance from the road surface. The ultrasonic sensor according to any one of claims 1 to 10.
A distance calculation unit configured to calculate the horizontal distance from the ultrasonic sensor to the object from the detection time of the first peak and the distances of the transmission unit and the reception unit from the road surface is further added. Prepare,
When the distance calculated by the distance calculation unit exceeds a predetermined value, the height determination unit is an ultrasonic sensor that does not determine the height of the object. An ultrasonic sensor mounted on a vehicle
With a transmission unit configured to transmit ultrasonic waves,
A receiving unit configured to receive the reflected wave generated by the ultrasonic wave reflected by an object, and
In the reflected wave, (1) the first peak whose reflected wave intensity is greater than the first threshold, and (2) the reflected wave intensity is greater than the second threshold smaller than the first threshold and less than the first threshold. A peak detection unit configured to perform peak detection processing for detecting a second peak whose detection time is earlier than the detection time of the first peak and within a predetermined set time from the detection time of the first peak. When,
An object height calculation configured to calculate the height of the object from the detection time of the first peak, the detection time of the second peak, and the distances of the transmission unit and the reception unit from the road surface. With the unit
Ultrasonic sensor with. The ultrasonic sensor according to any one of claims 1 to 11.
An object detection unit configured to detect the object based on the reflected wave when two types of transmitted waves having different directivities are transmitted is further provided.
When the object detection unit detects the object, the height determination unit is an ultrasonic sensor that determines the height of the object. The ultrasonic sensor according to claim 12.
An object detection unit configured to detect the object based on the reflected wave when two types of transmitted waves having different directivities are transmitted is further provided.
When the object detection unit detects the object, the object height calculation unit is an ultrasonic sensor that calculates the height of the object.

Images