JP2017181063A - Detection device and detection method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a detection device and a detection method with which it is possible to accurately detect a parkable section in a short time.SOLUTION: Provided is a detection device for detecting a parkable section on a side of a vehicle while the vehicle is traveling, comprising: a short wave transmission/reception unit for transmitting a first ultrasonic wave having a first wavelength to the side a number of times and receiving a first reflection wave that is reflected; a long wave transmission/reception unit provided behind the short wave transmission/reception unit in the travel direction of the vehicle, for transmitting a second ultrasonic wave having a second wavelength longer than the first wavelength to the side a number of times and receiving a second reflection wave that is reflected; a control unit for causing the long wave transmission/reception unit to start transmitting the second ultrasonic wave when the short wave transmission/reception unit does not receive the first reflection wave N times in succession (N is an integer equal to or greater than 2); and a detection unit for detecting a parkable section on the basis of the second reflection wave.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a detection device and a detection method for detecting a section where a vehicle can be parked.

  Conventionally, in order to support the parking operation when the driver parks the vehicle, the vehicle detects the obstacle on the side of the vehicle using a sensor such as sonar, and detects the section where the vehicle can be parked on the side. A support device is known (for example, Patent Document 1).

Japanese Patent No. 4045895

  However, conventionally, in order to detect a section where parking is possible with high accuracy, the sonar must be continuously driven after the start of detection, and the vehicle speed must be relatively low. There is a problem that it takes time to detect a possible section.

  The present invention has been made to solve such a problem, and an object of the present invention is to provide a detection device and a detection method capable of accurately detecting a section where parking is possible in a short time.

  The detection device of the present invention is a detection device that detects a side-parkable section of the vehicle while the vehicle is traveling, and transmits the first ultrasonic wave having the first wavelength to the side a plurality of times, A shortwave transmission / reception unit that receives the reflected first reflected wave, and a second wave that is provided behind the shortwave transmission / reception unit in the traveling direction of the vehicle and has a second wavelength that is longer than the first wavelength laterally. The long wave transmission / reception unit that transmits the ultrasonic wave multiple times and receives the reflected second reflected wave and the short wave transmission / reception unit continuously receive the first reflected wave N times (N is an integer of 2 or more). When there is not, the control part which starts transmission of a 2nd ultrasonic wave to a long wave transmission / reception part, and the detection part which detects the area which can be parked based on a 2nd reflected wave are provided.

  The detection method of the present invention is a detection method for detecting a side-parkable section of a vehicle while the vehicle is traveling, and a first ultrasonic wave having a first wavelength is transmitted laterally from a short-wave transmission / reception unit. When the first reflected wave is transmitted a plurality of times and is reflected, and the first reflected wave is not received N times (N is an integer of 2 or more) continuously, the vehicle traveling direction is The second reflected wave reflected by transmitting a second ultrasonic wave having a second wavelength longer than the first wavelength to the side from a long wave transmitting / receiving unit provided behind the short wave transmitting / receiving unit a plurality of times. , And a section where parking is possible is detected based on the received second reflected wave.

  According to the present invention, it is possible to accurately detect a section where parking is possible in a short time.

The block diagram which shows an example of a structure of the parking assistance system which concerns on embodiment of this invention. The figure which shows the 1st example of the procedure of the parking area detection in embodiment of this invention. The figure which shows the 2nd example of the procedure of the parking area detection in embodiment of this invention. The figure which shows the 3rd example of the procedure of the parking area detection in embodiment of this invention. The flowchart which shows the process sequence of the parking area detection process in embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings. Each embodiment described below is an example, and the present invention is not limited to these embodiments.

  FIG. 1 is a block diagram illustrating an example of a configuration of a parking assistance system 1 according to an embodiment of the present invention. The parking assist system 1 includes an electronic control unit (hereinafter referred to as ECU) 2, a front sonar 3, a rear sonar 4, and an engine 5.

  The front sonar 3 (short wave transmission / reception unit) is installed on both side surfaces of the front portion of the vehicle. The front sonar 3 receives a drive request from a sonar control unit 22 described later, and transmits a detection wave and receives a reflected wave at predetermined intervals.

  Specifically, the front sonar 3 is a short wave ultrasonic wave (first ultrasonic wave) having a relatively short wavelength (first wavelength) as a detection wave for detecting an obstacle existing near the side of the vehicle. Is transmitted in the direction directly outside the vehicle body. For example, the range in which the front sonar 3 detects an obstacle is a range from the side surface of the vehicle to a length that is about half the vehicle width. The front sonar 3 receives the reflected wave reflected by the obstacle. Then, the forward sonar 3 outputs the time difference from the transmission of the detection wave to the reception of the reflected wave to the sonar control unit 22 as the forward sonar detection information. Further, when the forward sonar 3 does not receive a reflected wave between the transmission of a detection wave and the transmission of the next detection wave, information indicating that there is no reflected wave (lost reflected wave) is detected by forward sonar detection. Information is output to the sonar control unit 22.

  The rear sonar 4 (long wave transmission / reception unit) is installed on both side surfaces on the rear side of the vehicle with respect to the front sonar 3. The rear sonar 4 receives a drive request from the sonar control unit 22 and transmits a detection wave and receives a reflected wave at predetermined intervals.

  Specifically, the rear sonar 4 has a relatively long wavelength (second wavelength longer than the first wavelength) as a detection wave for detecting an obstacle existing farther than the front sonar 3 on the side of the vehicle. The long wave ultrasonic wave (2nd ultrasonic wave) which it has is transmitted to the vehicle body right side outward direction. For example, the range in which the rear sonar 4 detects an obstacle is a range from the side surface of the vehicle to a length obtained by adding the half of the vehicle width and the vehicle length. Further, the rear sonar 4 receives the reflected wave reflected by the obstacle. Then, the rear sonar 4 outputs the time difference from the transmission of the detection wave to the reception of the reflected wave to the sonar control unit 22 as the rear sonar detection information.

  The engine 5 is a prime mover that generates driving force of the vehicle. The engine 5 generates driving force according to the amount of operation of the accelerator operated by the driver. Further, the engine 5 generates a target driving force under the control of a driving force control unit 23 described later.

  The ECU 2 includes a parking section detection unit 21, a sonar control unit 22, a driving force control unit 23, and an automatic parking processing unit 24.

  In response to a request for parking assistance from a driver or the like, the parking section detection unit 21 detects a section in which parking is possible for automatic parking (hereinafter referred to as a parking section). The request for parking assistance is made, for example, when a driver or the like presses a button on an operation unit (not shown). In addition, the detection method of a parking area is mentioned later.

  The parking section detection unit 21 outputs a detection start request for requesting the sonar control unit 22 to start detecting an obstacle, and the distance information obtained based on the detection results of the front sonar 3 and the rear sonar 4 from the sonar control unit 22. get. The parking section detection unit 21 detects a parking section based on the distance information and the vehicle speed (vehicle speed) acquired from the drive control unit 23 described later.

  The parking zone detection unit 21 notifies the sonar control unit 22 of a detection result indicating whether or not a parking zone has been detected. Moreover, the parking area detection part 21 outputs the drive request | requirement which shows starting the parking area information which shows the position of a parking area, and automatic parking to the automatic parking process part 24, when a parking area is detected.

  The sonar control unit 22 outputs a request to drive the front sonar 3 to the front sonar 3 based on the sonar drive request acquired from the parking section detection unit 21. Further, the sonar control unit 22 calculates the distance to the obstacle located in the vicinity of the vehicle side from the front sonar detection information acquired from the front sonar 3, and the distance information indicating the calculated distance is the parking section detection unit 21. Output to.

  When the sonar control unit 22 acquires the forward sonar detection information indicating the lost reflected wave from the forward sonar 3, it counts the number of times the reflected wave has been lost. The sonar control unit 22 outputs a request for driving the rear sonar 4 to the rear sonar 4 when the number of lost reflected waves reaches a threshold value N (N is a predetermined integer equal to or greater than 2). In addition, when the number of times of reflected wave loss reaches the threshold value N, the sonar control unit 22 outputs a driving force control request indicating that the vehicle speed is reduced to the driving force control unit 23.

  The sonar control unit 22 calculates distance information indicating the distance to the obstacle located far from the vehicle from the rear sonar detection information acquired from the driven rear sonar 4 and outputs the distance information to the parking section detection unit 21.

  The sonar control unit 22 stops driving the front sonar 3 and the rear sonar 4 when the detection result notification indicating that the parking section is detected is acquired from the parking section detection unit 21. When the sonar control unit 22 obtains from the parking section detection unit 21 a detection result notification indicating that the parking section has not been detected, the sonar control unit 22 stops driving the rear sonar 4 and continues to drive only the front sonar 3. At that time, the sonar control unit 22 outputs a driving force control request indicating that the vehicle speed is increased to the driving force control unit 23.

  Based on the current driving force acquired from the engine 5 and the target driving force indicated by the driving force control request acquired from the sonar control unit 22, the driving force control unit 23 causes the engine 5 to reach the target driving force. To control the driving force. Further, the driving force control unit 23 acquires the vehicle speed from a vehicle speed sensor (not shown) and outputs the vehicle speed to the parking section detection unit 21 and the automatic parking processing unit 24.

  The automatic parking processing unit 24 receives the parking section information and the driving request from the parking section detection unit 21 and starts the automatic parking process. Specifically, the automatic parking processing unit 24 controls the drive system device including the engine 5 of the vehicle, the brake system device including a brake (not shown), etc., and moves the vehicle to the position of the parking section indicated by the parking section information. Perform automatic parking to move.

  Next, the flow of the parking section detection process in the present embodiment will be described with reference to FIGS. In the following description, a parking section detection process using the front sonar 3 and the rear sonar 4 installed on the right side of the front sonar 3 and the rear sonar 4 installed on both side surfaces of the vehicle will be described. The parking zone detection process using the front sonar 3 and the rear sonar 4 installed on the left side is the same as the parking zone detection process using the front sonar 3 and the rear sonar 4 installed on the right side. The parking section detection process using the front sonar 3 and the rear sonar 4 installed on the left side and the parking section detection process using the front sonar 3 and the rear sonar 4 installed on the right side may be executed simultaneously. .

  FIG. 2 is a diagram illustrating a first example of a procedure for detecting a parking section in the present embodiment. In FIG. 2, the vehicle X traveling straight in the right direction detects the parking section P existing between the vehicle Y3 and the vehicle Y4 among the vehicles Y1 to Y7 parked in parallel on the right side when viewed from the traveling direction. The procedure to do is shown. In FIG. 2, states in which the vehicle X is detecting the parking section in the traveling direction of the vehicle X are shown as St1 to St6, and changes in the vehicle speed between the states are also shown. Moreover, in FIG. 2, the front sonar 3 provided in the front part on the right side of the traveling direction of the vehicle and the rear sonar 4 provided in the rear part on the right side transmit the detection wave.

  First, as shown in St1, the driver of the vehicle X makes a request for parking assistance, and detection by the front sonar 3 is started. In FIG. 2, while the vehicle X is traveling at a predetermined vehicle speed of medium speed (a speed that is faster than a low speed described later and slower than a high speed, for example, about 20 km / h to 40 km / h), the front sonar 3 A reflected wave is received from the front end part of vehicles Y1-Y3, and the position of the front end part of vehicles Y1-Y3 is detected.

  In St1, the front sonar 3 detects whether or not there is an obstacle on the side of the vehicle, specifically, a parked vehicle (primary detection). In primary detection, it is only necessary to detect whether or not a parked vehicle is present, so there is no need to make the detection interval fine. Therefore, in St1, primary detection by the forward sonar 3 can be performed without reducing the vehicle speed of the vehicle X.

  The front sonar 3 is in a state in which the reflected wave is not continuously received after detecting the position of the point F1 of the vehicle Y3. This state is due to the fact that no obstacle exists in the parking zone P within the distance that the front sonar 3 can detect. In this case, while the reflected wave is lost, the forward sonar 3 continuously outputs forward sonar detection information indicating the lost reflected wave to the sonar control unit 22 at a predetermined interval. When the sonar control unit 22 acquires the front sonar detection information indicating the lost reflected wave from the front sonar 3 continuously N times, the sonar control unit 22 drives the rear sonar 4 as indicated by St2. Further, the sonar control unit 22 sets the vehicle speed to a low speed (for example, 5 km / h).

  The result of the primary detection that the front sonar 3 does not receive the reflected wave N times consecutively means that a section where there is a high possibility that a parking section exists is detected. The sonar control unit 22 receives the result of the primary detection and starts detection of the parking section (secondary detection) by the rear sonar 4.

  As shown in St3, the rear sonar 4 receives the reflected wave from the obstacle W existing behind the parking section P when viewed from the vehicle X, and detects the position of the obstacle W. Note that while the rear sonar 4 is being driven, the front sonar 3 is also detecting.

  Next, when the position where the front sonar 3 of the vehicle X is provided passes through the parking section P and reaches a position where the front end of the vehicle Y4 can be detected, the front sonar 3 moves the front end of the vehicle Y4 as shown in St4. Multiple times (M times (M is a predetermined integer of 2 or more)) are detected. The sonar control unit 22 instructs the parking zone detection unit 21 to determine a parking zone, triggered by the fact that the front sonar 3 has been detected M times continuously.

  In response to the instruction from the sonar control unit 22, the parking section detection unit 21 calculates the position and size of the parking section P from the distance information and the vehicle speed acquired from the sonar control unit 22, and can the parking section P be parked? Determine whether or not.

  When parking is possible in the parking section P, the sonar control unit 22 stops the front sonar 3 and the rear sonar 4 as shown in St5. In addition, the parking section detection unit 21 causes the automatic parking processing unit 24 to start automatic parking. The automatic parking processing unit 24 temporarily stops the vehicle X and then starts automatic parking.

  When parking is not possible in the parking section P, the sonar control unit 22 stops the rear sonar 4 and performs primary detection by the front sonar 3 as shown in St6. At that time, the sonar control unit 22 requests the driving force control unit 23 to control the vehicle speed.

  FIG. 3 is a diagram illustrating a second example of the parking section detection procedure in the present embodiment. In FIG. 3, the vehicle X that goes straight to the right detects a parking section P that exists between the vehicle Y2 and the vehicle Y3 among the vehicles Y1 to Y4 that are parked in a column on the right side when viewed from the traveling direction. The procedure to do is shown. In FIG. 3, states where the vehicle X is detecting the parking section P in the traveling direction of the vehicle X are shown as St1 to St6, and changes in the vehicle speed between the states are also shown. Moreover, in FIG. 3, the front sonar 3 provided in the front part on the right side of the traveling direction of the vehicle and the rear sonar 4 provided in the rear part on the right side transmit the detection wave.

  St1 to St6 shown in FIG. 3 are the same as St1 to St6 shown in FIG. However, in St2, the threshold value N of the number of times the reflected wave is lost compared by the sonar control unit 22 at the time of determination differs between FIG. 2 and FIG.

  Specifically, the parking section P in the parallel parking shown in FIG. 2 only needs to have a width corresponding to at least the vehicle width in the direction parallel to the traveling direction of the vehicle X. On the other hand, the parking section P in the parallel parking shown in FIG. 3 requires at least a width corresponding to the vehicle length in a direction parallel to the traveling direction of the vehicle X. Therefore, it is preferable to increase the threshold value N when detecting the parallel parking parking section shown in FIG. 3 as compared with the case where the parallel parking parking section shown in FIG. 2 is detected.

  2 and 3, the case has been described in which the number of times the reflected wave is lost in the forward sonar 3 reaches the threshold value N. Next, the case where the number of times the reflected wave is lost in the forward sonar 3 is less than the threshold value N will be described with reference to FIG.

  FIG. 4 is a diagram showing a third example of the parking section detection procedure in the present embodiment. In FIG. 4, it is detected whether or not the vehicle X traveling straight in the right direction has a parking section between the vehicles Y1 to Y5 parked in parallel on the right side when viewed from the traveling direction. In FIG. 4, the state in which the vehicle X is detecting the parking section in the traveling direction of the vehicle X is shown as St11 to St13, and the vehicle speed in each state is also shown.

  First, as shown in St11, the driver of the vehicle X makes a request for parking assistance, and detection by the front sonar 3 is started. In FIG. 4, while the vehicle X is traveling at a medium speed, the front sonar 3 receives reflected waves from the front end portions of the vehicles Y1 to Y3 and detects the positions of the front end portions of the vehicles Y1 to Y3.

  Since the front sonar 3 does not receive an reflected wave as shown in St12 after detecting the position of the point F11 of the vehicle Y3 because there is no obstacle in the section T within the distance that the front sonar 3 can detect. Become. In this case, the forward sonar 3 continuously outputs forward sonar detection information indicating the lost reflected wave to the sonar control unit 22 while the reflected wave is lost.

  In the case of the example of FIG. 4, the number of times the front sonar 3 loses the reflected wave in the section T is less than the threshold value N. Therefore, the sonar control unit 22 continues the detection of the parking section as indicated by St3 in a state where only the front sonar 3 is driven without driving the rear sonar 4. At that time, the sonar control unit 22 does not suppress the vehicle speed.

  As shown in FIG. 4, when the number of times the reflected wave is lost continuously in the front sonar 3 is less than the threshold value N, the frequency of driving the rear sonar 4 can be reduced by not driving the rear sonar 4, Power consumption in the parking section detection process can be suppressed. Further, by not suppressing the vehicle speed, the frequency of changing the vehicle speed can be reduced, and the parking section detection process can be executed at high speed.

  Next, parking section detection processing in the present embodiment will be described with reference to FIG.

  FIG. 5 is a flowchart of parking section detection processing in the present embodiment. The parking section detection process is started, for example, when a parking assistance request is received from a driver or the like.

  The sonar control unit 22 starts transmitting and receiving the front sonar 3 by outputting a driving request for the front sonar 3 (S101).

  Next, the sonar control unit 22 determines whether or not the loss of the reflected wave in the front sonar 3 has been continuously generated N times (S102).

  If the reflected wave lost in front sonar 3 has not occurred N times consecutively (NO in S102), the process of S102 is executed again.

  When lost in front sonar 3 has occurred N times consecutively (YES in S102), sonar control unit 22 outputs a request for driving force control indicating that the vehicle speed is to be lowered to driving force control unit 23, thereby increasing the speed. The suppression control is started (S103).

  Next, the sonar control unit 22 starts transmission and reception of the rear sonar 4 by outputting a drive request for the rear sonar 4 (S104).

  Next, the parking section detection unit 21 detects the presence or absence of a parking section (S105).

  Specifically, as indicated by St4 in FIGS. 2 and 3, the sonar control unit 22 detects the parking section when the front sonar 3 continuously receives the reflected wave M times, and detects the parking section. 21. The parking section detection unit 21 detects the presence or absence of a parking section where the vehicle can be parked based on the distance information detected by the rear sonar 4 and the vehicle speed.

  When there is no parking section (NO in S105), the sonar control unit 22 stops the rear sonar 4 by outputting a request to stop the rear sonar 4 (S106).

  Next, the sonar control unit 22 recovers the vehicle speed by outputting a driving force control request indicating an increase in the vehicle speed to the driving force control unit 23 (S107). For example, the sonar control unit 22 outputs a driving force control request so as to increase the vehicle speed decreased in S103. Then, S102 is executed again.

  If there is a parking section at S105 (YES at S105), sonar control unit 22 stops front sonar 3 and rear sonar 4 by outputting a stop request to front sonar 3 and rear sonar 4 (S108). ).

  Next, the sonar control unit 22 stops the vehicle by outputting a driving force control request indicating that the vehicle is to be stopped to the driving force control unit 23 (S109).

  The parking section detection unit 21 starts automatic parking control by outputting information indicating the detected parking section and information indicating a drive request to the automatic parking processing unit 24 (S110). Then, the parking section detection process ends.

  In addition, in S103 of FIG. 5, the example in which the sonar control unit 22 performs the control to suppress the vehicle speed when the reflected wave lost in the front sonar 3 occurs N times continuously has been described, but the present invention is not limited to this. . The parking zone can also be detected by driving the rear sonar 4 without suppressing the vehicle speed when the reflected wave lost in the front sonar 3 occurs N times continuously. In this case, the process for recovering the vehicle speed described in S107 is not executed.

  Moreover, although the sonar control part 22 demonstrated the example which starts the detection of a parking area when the front sonar 3 received the reflected wave M times continuously in S105 of FIG. 5, this invention is limited to this. Not. The parking section detection unit 21 may detect the parking section based on the distance information and the vehicle speed detected by the rear sonar 4 before the front sonar 3 continuously receives the reflected wave M times.

  Further, the sonar control unit 22 may stop driving the front sonar 3 before the process of S105 is executed. In this case, the sonar control unit 22 causes the parking zone detection unit 21 to start detecting the parking zone without determining whether or not the front sonar 3 has continuously received the reflected wave M times. The parking section detection unit 21 detects a parking section based on the distance information detected by the rear sonar 4 and the vehicle speed.

  As described above, according to the above-described embodiment, the sonar control unit 22 drives the front sonar 3 without reducing the vehicle speed, thereby detecting a section where there is a high possibility that a parking section exists using a short wave. Execute. And the sonar control part 22 performs the secondary detection in which the back sonar 4 detects a parking area using a long wave, triggered by the fact that the reflected wave is lost N times continuously in the front sonar 3.

  With this configuration, it is possible to accurately detect a high-speed parking section without reducing the vehicle speed. Further, when the reflected wave is lost N times consecutively in the front sonar 3, the rear sonar 4 starts detection, so that it is possible to suppress power consumption in parking section detection.

  Moreover, according to the said embodiment, the sonar control part 22 may reduce a vehicle speed by using as a trigger that the reflected wave was lost N times continuously in the front sonar 3. FIG. With this configuration, since the rear sonar 4 can detect in detail the presence or absence of an obstacle in a section where there is a high possibility that a parking section exists, the detection accuracy of the parking section can be improved.

  The present invention is suitable for use in a vehicle parking assistance system.

1 Parking support system 2 ECU
DESCRIPTION OF SYMBOLS 3 Front sonar 4 Back sonar 5 Engine 21 Parking area detection part 22 Sonar control part 23 Driving force control part 24 Automatic parking process part

Claims (5)

A detection device that detects a section of the vehicle that can be parked while the vehicle is running,
A short-wave transceiver for transmitting the first ultrasonic wave having the first wavelength to the side a plurality of times and receiving the reflected first reflected wave;
A second ultrasonic wave that is provided behind the short wave transmission / reception unit with respect to the traveling direction of the vehicle and that has a second wavelength longer than the first wavelength is transmitted to the side and reflected several times. A long wave transmission / reception unit for receiving the second reflected wave;
Control that causes the long wave transmitting / receiving unit to start transmitting the second ultrasonic wave when the short wave transmitting / receiving unit has not received the first reflected wave N times (N is an integer equal to or greater than 2). And
Based on the second reflected wave, a detection unit that detects the section where parking is possible;
A detection device comprising: The controller is
When the short wave transmission / reception unit does not continuously receive the first reflected wave of N times, the speed of the vehicle is reduced,
When the detection unit does not detect the section where parking is possible, the speed of the vehicle is increased.
The detection device according to claim 1. The controller is
The long wave transmission / reception unit starts transmission of the second ultrasonic wave, and the short wave transmission / reception unit stops transmission of the first ultrasonic wave,
When the detection unit does not detect the section where the parking is possible, the short wave transmission / reception unit starts transmission of the first ultrasonic wave,
The detection device according to claim 1 or 2. The detection unit receives the first reflected wave M times (M is an integer of 2 or more) continuously after the long wave transmission / reception unit starts transmission of the second ultrasonic wave. When the parking area is detected,
The detection device according to claim 1 or 2. A detection method for detecting a section of the vehicle that can be parked while the vehicle is running,
From the short wave transmission / reception unit, the first ultrasonic wave having the first wavelength is transmitted to the side a plurality of times,
Receiving the reflected first reflected wave;
A long wave transmission / reception unit provided behind the short wave transmission / reception unit with respect to the traveling direction of the vehicle when the first reflected wave of N times (N is an integer of 2 or more) is not received continuously. From the side, the second ultrasonic wave having a second wavelength longer than the first wavelength is transmitted a plurality of times to the side,
Receiving the reflected second reflected wave;
Based on the received second reflected wave, the parkable section is detected.
Detection method.

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