JP5652278B2 - Parking space detection device - Google Patents

Description

  The present invention relates to a parking space detection device that detects a parking space in which a host vehicle can be parked.

  Conventionally, this type of detection device includes a distance measuring sensor that transmits a sound wave and receives a reflected wave of the sound wave in a parked vehicle to detect distance data from the own vehicle to the parked vehicle. When passing the side, the distance is repeatedly detected by the distance measuring sensor, the contours of the two parked vehicles are estimated using the distance data for each of the detected measurement positions, and the two units are based on the estimated contours. There is one that determines a parking space as a space between the parked vehicles.

  As for estimating the outline of such a parked vehicle, when the host vehicle passes by the side of the parked vehicle, it is repeatedly detected by a distance measuring sensor to obtain distance data for each measurement position, and the obtained measurement position Point sequence data indicating a sequence of sound wave detection points in a parked vehicle is obtained using a plurality of sets of distance data of two adjacent measurement positions among the distance data. The detection point is a part estimated as a reflection point where sound waves are reflected in the parked vehicle. There is one that estimates the contour shape of a parked vehicle by performing curve approximation on the point sequence data of such detection points (see, for example, Patent Document 1).

JP 2008-21039 A

  The inventors of the present invention have studied to obtain a highly accurate detection point in order to estimate the parking space with high accuracy. As a result, the first level at which the reception level of the reflected wave first peaks after the sound wave is transmitted in the distance measuring sensor. When the detection point is obtained with the peak time as the time of receiving the reflected wave, as shown in FIG. 10, when the host vehicle 40 passes near the front side in the traveling direction of the parked vehicle 50, the corner of the parked vehicle 50. Since the vicinity of the portion 50a is detected as a detection point, it may not be obtained as a detection point for the most distal portion 50b of the parked vehicle 50.

  This is because, in the case where the detection point is provided with the time of the first peak when the reflected wave is received, the range sensor 10 and the parked vehicle 50 in the range where the sound wave reaches from the range sensor 10 in the parked vehicle 50 This is because the detection point having the shortest distance between the two is obtained. That is, even if the host vehicle 40 passes the side of the parked vehicle 50, it cannot be obtained as a detection point for the most distal portion 50b of the parked vehicle 50.

  Thus, when the most advanced part of the parked vehicle 50 cannot be obtained as a detection point, the parking space cannot be determined with high accuracy. Such a problem may also occur when a detection point for an obstacle other than the parked vehicle 50 is obtained.

  An object of this invention is to provide the parking space detection apparatus which enabled it to determine the parking space between two obstacles accurately in view of the said point.

To achieve the above object, according to the invention of claim 1, 2, when the vehicle (40) two obstacles progression are arranged in the direction of the vicinity of the (50, 51) is the vehicle moves Transmitting / receiving means (10) for repeatedly transmitting a search wave to the two obstacles and receiving a search wave reflected by one of the two obstacles;
Position detecting means (12a, 12b) for detecting a plurality of measurement positions at which the transmitting / receiving means transmits / receives the exploration wave;
Of the plurality of measurement positions, at the measurement position on the rear side in the traveling direction among the plurality of measurement positions corresponding to the obstacle (51) on the front side in the traveling direction, First path length calculation for calculating the first path length of the exploration wave based on the time from transmission to reception of the exploration wave for the time of reception when the reception level becomes the second or later peak. Means (S410);
Among the plurality of measurement positions, at the measurement position on the front side in the traveling direction among the plurality of measurement positions corresponding to the obstacle (50) on the rear side in the traveling direction, Second path length calculation for calculating the second path length of the exploration wave based on the time from transmission to reception of the exploration wave at the time when the reception level reaches the second and subsequent peaks at the time of reception. Means (S410);
The first path length of the two adjacent measurement positions and the position information of the two adjacent measurement positions among the first path lengths for each of the measurement positions calculated by the first path length calculation means. A first detection point calculation means (S510a) for calculating a first detection point of the exploration wave with respect to the obstacle (51) on the front side in the traveling direction using triangulation;
Among the second path lengths for each of the measurement positions calculated by the second path length calculation means, the second path lengths of the two adjacent measurement positions and the position information of the two adjacent measurement positions And second detection point calculation means (S510) for calculating a second detection point of the exploration wave for the obstacle (50) on the rear side in the traveling direction by triangulation,
Position information of the first detection point of the obstacle ahead of the traveling direction calculated by the first detection point calculating means and the obstacle behind the traveling direction calculated by the second detection point calculating means And determining means (S170) for determining a parking space between the two obstacles based on the positional information of the second detection point.

  Here, the detection point is a part estimated as a reflection point where the exploration wave is reflected from the obstacle.

  Here, the triangulation is a method in which two adjacent measurement positions are X1 and X2, a path length r1 of the measurement position X1, a path length r2 of the measurement position X2, and a radius r1 around the measurement position X1 as a center. When the second circle is drawn with the measurement position X2 as the center and r2 as the radius, the intersection of the first circle and the second circle is obtained as the detection point.

  Here, the path length is the length of a one-way path among the paths from when the exploration wave is transmitted from the measurement position and reflected by the obstacle until it is received at the measurement position.

According to the first and second aspects of the present invention, the first and second path length calculation means respectively calculate the path length from the time when the second and subsequent peaks are received. For this reason, a longer path length is obtained as compared with the case where the path length of the exploration wave is obtained at the time of reception when the reception level of the exploration wave first peaks. For this reason, the detection point as the front end part (F) in the traveling direction of the obstacle (50) on the rear side in the traveling direction can be obtained with high accuracy. In addition to this, the detection point as the rear end (R) in the traveling direction of the obstacle (51) on the front side in the traveling direction can be obtained with high accuracy. Thus, the traveling direction front end (F) of the traveling direction rear obstacle (50) and the traveling direction rear end (R) of the traveling direction front obstacle (51) can be obtained accurately. Therefore, the parking space between the obstacle (50) on the rear side in the traveling direction and the obstacle (51) on the front side in the traveling direction can be accurately determined.

In the first aspect of the present invention, at the plurality of measurement positions detected by the position detection unit, the time at which the reception level of the reflected wave first peaks after transmission of the exploration wave by the transmission / reception unit is Third path length calculating means (S110) for calculating, for each measurement position, a third path length of the exploration wave based on a time from transmission to reception of the exploration wave when receiving the exploration wave;
Using the third path length of any two adjacent measurement positions among the plurality of measurement positions detected by the position detection means and a plurality of sets of position information of the two adjacent measurement positions, A third detection point calculating means (S200) for calculating a plurality of third detection points of the exploration wave in the obstacle (50) on the side and the obstacle (51) on the front side in the traveling direction by triangulation;
Rear side detection located on the rear side in the traveling direction among the plurality of third detection points of the exploration wave in the obstacle (51) on the front side in the traveling direction calculated by the third detection point calculating means (S200). Rear detection point calculation means (S2 8 0) for obtaining the point (R2);
The front detection point (F1) located on the front side in the traveling direction among the plurality of third detection points of the exploration wave in the obstacle on the rear side in the traveling direction calculated by the third detection point calculating means (S200). Front side detection point calculation means (S2 4 0) for obtaining
Of the plurality of measurement positions corresponding to the obstacle (51) on the front side in the traveling direction, a measurement position located on the rear side in the traveling direction from the rear detection point (R2) is used as the first path length calculating means (S410). ) As the measurement position on the rear side in the traveling direction for calculating the first path length, and the front detection point (F1) among the plurality of measurement positions corresponding to the obstacle (50) on the rear side in the traveling direction. Further, the measurement position located on the front side in the traveling direction is set as the measurement position on the front side in the traveling direction for calculating the second path length by the second path length calculating means (S410).

In the invention according to claim 2 , at the plurality of measurement positions detected by the position detection unit, the time at which the reception level of the reflected wave first peaks after the transmission of the search wave by the transmission / reception unit is Third path length calculating means (S110) for calculating, for each measurement position, a third path length of the exploration wave based on a time from transmission to reception of the exploration wave when receiving the exploration wave;
Based on the position information for each measurement position and the third path length for each measurement position, the change ratio (Ln ″) of the change ratio of the third path length to the measurement position is a predetermined value or less. A front measurement position selection means (S612) for selecting a first measurement position (R2 ′) that is the measurement position and is located most rearward in the traveling direction;
Among the plurality of measurement positions, among the plurality of measurement positions corresponding to the obstacle (50) on the rear side in the traveling direction, the change ratio (Ln ″) of the change ratio of the third path length with respect to the measurement position is predetermined. A rear measurement position selection means (S603) for selecting a second measurement position (F1 ′) that is a measurement position that is equal to or less than a value and that is located closest to the front in the traveling direction,
Of the plurality of measurement positions corresponding to the obstacle (51) on the front side in the traveling direction, a measurement position located on the rear side in the traveling direction with respect to the first measurement position (R2 ′) is defined as the first path length calculation unit. (S410) as the measurement position on the rear side in the traveling direction for calculating the first path length,
Of the plurality of measurement positions corresponding to the obstacle (50) on the rear side in the traveling direction, a measurement position located on the front side in the traveling direction with respect to the second measurement position (F1 ′) is calculated as the second path length. The measurement position on the front side in the traveling direction for calculating the second path length by means (S410) is characterized.

According to a third aspect of the invention, of the first path lengths for each of the measurement positions calculated by the first path length calculation means, the first detection point calculation means is an obstacle on the front side in the traveling direction. First path length selection means (S470a) for selecting the first path length of the two adjacent measurement positions used when calculating the first detection point of (51);
Of the second path lengths for each of the measurement positions calculated by the second path length calculation means, the second detection point calculation means performs the second of the obstacles (50) on the rear side in the traveling direction. Second path length selection means (S470) for selecting the second path length of the two adjacent measurement positions used when calculating a detection point;
The first path length selection means is configured to detect the two adjacent measurement positions so that the first path length is longer at the measurement position on the rear side in the traveling direction than on the measurement position on the front side in the traveling direction. Selecting the first path length;
The second path length selection means is configured to detect the two adjacent measurement positions so that the second path length is longer at the measurement position on the front side in the traveling direction than on the measurement position on the rear side in the traveling direction. Selecting the second path length;
The first detection point calculation means (S510a) uses the first path lengths of the two adjacent measurement positions selected by the first path length selection means to obstruct the front side in the traveling direction. Calculating a first detection point of the exploration wave in (51);
The second detection point calculation means (S510) uses the second path lengths of the two adjacent measurement positions selected by the second path length selection means to cause an obstacle on the rear side in the traveling direction. A second detection point of the exploration wave in the object (50) is calculated.

According to the third aspect of the present invention, when calculating the detection point as the rear end portion in the traveling direction among the obstacles (51) on the front side in the traveling direction, the first path length selection means is provided on the front side in the traveling direction. The path lengths of two adjacent measurement positions are selected so that the path length is longer at the measurement position on the rear side in the traveling direction than the measurement position.

  Here, among the obstacles (51) on the front side in the traveling direction, on the rear side in the traveling direction with respect to the rear end (R) in the traveling direction, the adjacent measurement position (Xn) on the front side in the traveling direction and the rear side in the traveling direction. The measurement position (Xn-1) has the following relationship.

  That is, the measurement position (Xn-1) on the rear side in the traveling direction and the obstacle are larger than the distance between the measurement position (Xn) on the front side in the traveling direction and the rear end (R) in the traveling direction of the obstacle (51). The distance between the rear end portion (R) in the traveling direction of (51) becomes longer. For this reason, according to the fourth aspect of the present invention, as described above, the first path length selection means is configured such that the path length is longer at the measurement position on the rear side in the traveling direction than on the measurement position on the front side in the traveling direction. By selecting the path lengths of the two measurement positions adjacent to each other, it is possible to suppress the calculation of the part other than the rear end (R) in the traveling direction among the obstacles (51) in the forward traveling direction as detection points. it can.

In addition, according to the invention described in claim 3 , when calculating the detection point as the front end (F) in the traveling direction among the obstacles (50) (50) on the rear side in the traveling direction, The second path length selection means selects the path lengths of two adjacent measurement positions so that the path length of the measurement position on the front side in the traveling direction is longer than the measurement position on the rear side in the traveling direction.

  Here, of the obstacle (50) on the rear side in the traveling direction, the measurement position (Xn) on the rear side in the traveling direction and the measurement position on the front side in the traveling direction (on the front side in the traveling direction with respect to the front end (F) in the traveling direction) Xn + 1) has the following relationship.

  That is, the measurement position (Xn + 1) and the obstacle (50) on the front side in the traveling direction rather than the distance between the measurement position (Xn) on the rear side in the traveling direction and the front end part (F) in the traveling direction of the obstacle (50). The distance from the front end (F) in the traveling direction becomes longer.

For this reason, according to the third aspect of the present invention, the second path length selecting means is adjacent to the measurement position on the front side in the traveling direction so that the path length is longer than the measurement position on the rear side in the traveling direction. Since the path lengths of the two measurement positions are selected, it is possible to suppress the calculation of the part other than the front end (F) in the traveling direction among the obstacles (50) on the rear side in the traveling direction as detection points.

  As described above, the traveling direction front end (F) of the traveling direction rear obstacle (50) and the traveling direction rear end (R) of the traveling direction front obstacle (51) can be accurately calculated. it can.

In the invention according to claim 4, when the first detection point calculation means (S510a) calculates a plurality of the first detection points in the obstacle (51) on the front side in the traveling direction, the traveling direction is expressed as X. The average value of the X-coordinate values at the plurality of first detection points of the obstacle (51) on the front side in the traveling direction when the direction is set as the direction is the rear end in the traveling direction of the obstacle (51) on the front side in the traveling direction. First average value calculating means (S560a) for calculating as part position information;
When the second detection point calculation means (S510) calculates a plurality of the second detection points in the obstacle (50) on the rear side in the traveling direction, the traveling direction is determined when the traveling direction is the X direction. An average value of X-coordinate values at the plurality of second detection points of the rear obstacle (50) is calculated as position information of a front end portion in the advancing direction of the obstacle (50) in the advancing direction. Second average value calculating means (S560),
The determining means (S170) is based on the average value of the X coordinate values calculated by the first average value calculating means and the average value of the X coordinate values calculated by the second average value calculating means. It is characterized by determining a parking space between two obstacles.

According to the fourth aspect of the present invention, the positional information of the front end (F) in the traveling direction of the obstacle (50) on the rear side in the traveling direction and the rear end in the traveling direction of the front obstacle (51) in the traveling direction. The position information (R) can be calculated with high accuracy. For this reason, the determination means can determine the parking space with high accuracy.

In the invention according to claim 5 , the first detection point calculation means (S510a) falls within a predetermined range among the plurality of first detection points in the obstacle (51) on the front side in the traveling direction. First detection point selection means (S520a) for selecting a plurality of first detection points;
A plurality of second detection points that fall within a predetermined range among the plurality of second detection points in the obstacle (50) on the rear side in the traveling direction calculated by the second detection point calculation means (S510). Second detection point selection means (S520) to select,
The first average value calculation means (S560a) calculates an average value of X coordinate values at a plurality of first detection points selected by the first detection point selection means as an obstacle (front side in the traveling direction) 51) as the position information of the rear end portion in the traveling direction of 51),
The second average value calculation means (S560) calculates an average value of X coordinate values at a plurality of second detection points selected by the second detection point selection means as an obstacle on the rear side in the traveling direction. (50) is calculated as position information of the front end portion in the traveling direction.

According to the fifth aspect of the present invention, it is assumed that the detection point falls within a predetermined range if it is a detection point at the rear end (F) in the traveling direction of the obstacle (51) on the front side in the traveling direction. The first average value calculation means (S560a) uses the average value of the X coordinate values at the plurality of detection points selected by the first detection point calculation means as the traveling direction of the obstacle (51) on the front side in the traveling direction. Calculated as position information of the rear end (R). For this reason, it is possible to accurately calculate the position information of the rear end (R) in the traveling direction of the obstacle (50) on the front side in the traveling direction.

  In addition to this, if it is a detection point of the front end (F) in the traveling direction of the obstacle (50) on the rear side in the traveling direction, the second average value assumes that the detection point falls within a predetermined range. The calculation means (S560) calculates the average value of the X coordinate values at the plurality of detection points selected by the second detection point calculation means as the position of the front end portion in the traveling direction of the obstacle (50) on the rear side in the traveling direction. Calculate as information. For this reason, it is possible to accurately calculate the position information of the front end portion (F) in the traveling direction of the obstacle (50) on the rear side in the traveling direction.

  Accordingly, the position information of the rear end portion (R) in the traveling direction of the obstacle (51) on the front side in the traveling direction and the position information on the front end portion (F) in the traveling direction of the obstacle (50) on the rear side in the traveling direction, respectively. It can be detected with high accuracy.

Further, as in the invention described in claim 5 , the average value of the X coordinate values at the plurality of detection points selected by the first detection point calculating means is used as the traveling direction of the obstacle (51) on the front side in the traveling direction. Not only the position information of the rear end (R) but also the X coordinate value of the detection point on the rear side in the traveling direction among the plurality of detection points selected by the first detection point calculating means The position information of the rear end (R) in the traveling direction of the front obstacle (51) may be used.

  In addition to this, the average value of the X-coordinate values at the plurality of detection points selected by the second detection point calculating means is used as the position information of the front end in the traveling direction of the obstacle (50) on the rear side in the traveling direction. The position information of the detection point on the front side in the traveling direction among the plurality of detection points selected by the second detection point calculating means is not limited to the case, and the front end in the traveling direction of the obstacle (50) on the rear side in the traveling direction. It is good also as position information.

  In addition, the code | symbol in the bracket | parenthesis of each means described in this column and the claim shows the correspondence with the specific means as described in embodiment mentioned later.

It is a block diagram which shows the structure of the parking assistance apparatus in 1st Embodiment of this invention. It is a schematic diagram which shows a movement of the vehicle carrying the parking assistance apparatus of the said 1st Embodiment. It is a schematic diagram which shows a movement of the vehicle carrying the parking assistance apparatus of the said 1st Embodiment. It is a flowchart which shows the transmission / reception process of parking assistance ECU of the said 1st Embodiment. It is a flowchart which shows the whole parking space determination process of the parking assistance ECU of the said 1st Embodiment. It is a flowchart which shows the detail of the one part process of the partial parking space determination process of the said parking space determination process. It is a flowchart which shows the detail of a part of process of the said parking space determination process. It is a flowchart which shows the detail of a part of process of the said parking space determination process. It is a schematic diagram which shows each detection point calculated | required with execution of the said parking space determination process. It is a figure for demonstrating the effect of the said 1st Embodiment. It is a figure which shows the actual measurement result in the detection point of the said 1st Embodiment. It is a figure which shows the detection accuracy of the vehicle end of the said 1st Embodiment. It is a flowchart which shows the whole parking space determination process of parking assistance ECU in 1st Embodiment of this invention.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the following embodiments, parts that are the same or equivalent to each other are given the same reference numerals in the drawings in order to simplify the description.

(First embodiment)
Next, this embodiment of the parking assistance apparatus to which the parking space detection apparatus according to the present invention is applied will be described with reference to FIG. FIG. 1 is a block diagram showing the configuration of the parking assistance apparatus of the present embodiment.

  The parking assistance device 1 of the present embodiment includes a distance measuring sensor 10, a parking switch 11, a vehicle speed sensor 12a, a steering angle sensor 12b, and a parking assistance ECU 13.

  The distance measuring sensor 10 constitutes transmission / reception means, and includes a transmitter that transmits a search wave as an ultrasonic wave and a receiver that receives a reflected wave of the search wave reflected by an obstacle and outputs a reception signal. It is configured. The distance measuring sensor 10 is disposed on the side of the vehicle (own vehicle) 40 (see FIG. 2). FIG. 2 shows an example in which the distance measuring sensor 10 is arranged on the vehicle 40. Reference numeral 10a in FIG. 2 schematically shows a survey wave transmitted from the distance measuring sensor 10 or a reflected wave reflected by an obstacle.

  The parking switch 11 is a switch operated by an occupant, and is used to instruct the parking support ECU 13 to start execution of the control process. The vehicle speed sensor 12a is a sensor that detects the speed of the vehicle. The steering angle sensor 12b is a sensor that detects the steering angle of the steering wheel of the vehicle. The vehicle speed sensor 12a and the rudder angle sensor 12b constitute position detecting means.

  The parking assist ECU 13 is an electronic control device that includes a microcomputer, a memory, a counter, a register, and the like. The parking assist ECU 13 executes transmission / reception processing for repeatedly transmitting the exploration wave by the distance measuring sensor 10, receiving the reflected wave of the exploration wave for each transmission, and storing the reflected wave data indicating the received signal. The reflected wave data is data indicating a change in the signal level of the received signal over time after the transmission of the exploration wave. The parking assistance ECU 13 is based on a parking space determination process for determining the position information of the parking space between the two parked vehicles 50 and 51 according to the reflected wave data for each transmission of the exploration wave, and the position information of the parking space. A target rudder angle calculation process of calculating a target rudder angle of the steering wheel and outputting it to the steering control ECU 30 is executed. The steering control ECU 30 is an electronic control device that automatically controls the angle of the steering wheel according to the target steering angle when the vehicle 40 is parked in parallel, for example. Parallel parking is to park the vehicle 40 between two obstacles (parked vehicles) by moving the vehicle 40 backward.

  Next, the transmission / reception process and the parking space determination process of the parking assistance ECU 13 of this embodiment will be described separately.

  First, the transmission / reception process will be described. In the transmission / reception process, before the vehicle (own vehicle) 40 parks between the parked vehicles 50 and 51, as shown in FIG. This is executed when passing through the side as shown by arrows A and B in FIG. 2 (FIG. 3). The parked vehicles 50 and 51 are arranged in the traveling direction of the vehicle 40. Execution of the transmission / reception process is started when the parking switch 11 is operated and turned on by the passenger.

  FIG. 4 is a flowchart showing transmission / reception processing. The parking assistance ECU 13 executes transmission / reception processing according to the flowchart of FIG.

  First, in step S90 of FIG. 4, a search wave is transmitted from the transmitter of the distance measuring sensor 10. When this exploration wave reaches one of the parked vehicles 50 and 51, the reached exploration wave is reflected by the one parked vehicle. When this reflected reflected wave is received by the receiver of the distance measuring sensor 10, the receiver of the distance measuring sensor 10 outputs a reception signal based on the reflected wave. Accordingly, the reflected wave data corresponding to the received signal is stored in the memory.

  In the next step S91, position information of the distance measuring sensor 10 is obtained based on the output signal of the vehicle speed sensor 12a and the output signal of the steering angle sensor 12b. As a result, position information of the position of the distance measuring sensor 10 (hereinafter referred to as “measurement position”) that has transmitted the exploration wave by the distance measuring sensor 10 and received the reflected wave is obtained. In the next step S92, it is determined whether or not a certain period of time has elapsed since the transmission of the exploration wave. When it is determined NO that the elapsed time after the exploration wave transmission has not elapsed for a certain period, the process returns to step S92. Thereafter, when the elapsed time after the transmission of the exploration wave is less than a certain period, the NO determination is repeated in step S92. Then, when the elapsed time after the exploration wave transmission is equal to or longer than a certain period, YES is determined in step S92. Thereafter, in step S93, it is determined based on the output signal of the transmission whether or not the gear position of the automatic transmission of the vehicle is in the reverse mode (that is, the reverse mode). When the gear position of the automatic transmission is in a gear position other than the reverse mode (for example, drive mode), it is determined as NO and the process returns to step 90.

Therefore, the exploration wave transmission / reception wave data storage process in step 90, the position information detection process in step S91, and the determination process in step S92 are repeated until the automatic transmission is set to the reverse mode. For this reason, detection of position information and storage of the reflected wave data P _n are performed for each measurement position Xn. n is the number of the measurement position X where the minimum value is 1 and the maximum value is N, and also shows the correspondence between the reflected wave data P _n and the measurement position Xn. When n = 1, the measurement position Xn indicates the rearmost measurement position in the traveling direction, and when n = N, the measurement position Xn indicates the frontmost measurement position in the traveling direction.

Thereafter, if the automatic transmission is set to the reverse mode after passing the side of the parked vehicles 50 and 51, YES is determined in step S93. As a result, the transmission / reception process is terminated. As a result, the storage of the reflected wave data P _n for each measurement position Xn corresponding to each of the parked vehicles 50 and 51 ends.

  Next, details of the parking space determination process will be described. FIG. 5 is a flowchart showing parking space determination processing, and FIG. 6 is a flowchart showing details of step S140 in FIG. 7 and 8 are flowcharts showing details of step S150 in FIG.

  The parking assist ECU 13 executes a parking space determination process according to the flowcharts of FIGS. 5, 6, 7, and 8. The execution of the parking space determination process is started after completion of the transmission / reception process.

First, in step S100 of FIG. 5, to obtain the reflected wave data P _n for each measurement position Xn (n = 1~N) from the memory. That is, the reflected wave data P ₁ , P ₂ , P ₃ ,... P _N−1 , P _N are acquired from the memory.

Here, as will be described later, the reflected wave data P ₁ , P ₂ , P ₃ ,... P _N−1 , P _N are the reflection time of the first peak and the reflection time of the second and subsequent peaks. Used to find out.

  The reflection time of the first peak is a reflection time having a reception timing that is a peak timing at which the signal level of the reception signal first peaks after the transmission of the exploration wave. Time until peak timing. That is, the reflection time is the time from when an exploration wave is transmitted until it is reflected and received by an obstacle such as a parked vehicle 50, 51.

  In the present embodiment, it is determined that a peak has occurred when the signal level of the received signal exceeds a predetermined value after transmitting the exploration wave. Hereinafter, the peak timing at which the signal level of the received signal first peaks after the transmission of the exploration wave is referred to as a first peak timing.

Therefore, in the next step S110 (third path length calculation means), the reflection time of the first peak is obtained for each measurement position Xn based on the reflected wave data _Pn for each measurement position Xn, and this first peak is obtained. The path length L _n is calculated for each measurement position Xn from the reflection time. That is, the path lengths L ₁ , L ₂ ,... L _N are calculated from the reflected wave data P _{n for} each measurement position Xn. Path length L _n is half the value of the value obtained by multiplying the speed of sound to the reflection time of the first peak. The path length L _n corresponds to the third path length in the claims.

Here, the signal level of the received signal is less than a predetermined value for a certain period or longer after the exploration wave is transmitted (that is, the signal level of the received signal does not peak for a certain period or more after the exploration wave is transmitted). At the measurement position Xn, the path length L _{n is set} to zero (that is, L _n = 0). Therefore, in the first vehicle section measurement position Xn is continuous on the side of the parked vehicle 50, the path length L _n of each measurement position Xn is a positive value, respectively. In the second vehicle section measurement position Xn is continuous on the side of the parked vehicle 51, the path length L _n of each measurement position Xn is a positive value, respectively. Then, in the transmitted segment repeated probing wave by the distance measuring sensor 10 between the parked vehicles 50 and 51, so that the path length L _n is zero measuring position Xn is continuous. Hereinafter, this measurement position Xn path length L _n is zero between the parked vehicles 50, 51 a section are continuous in that the path length zero interval.

In the next step S120, each reflected wave data P _n (n = 1 to N) acquired in step S100 is divided for each parked vehicle. Specifically, each reflected wave data P _n at each measurement position Xn of the vehicle traveling direction rear side of the path length zero interval of the reflected wave data P _n, each traveling direction of the vehicle front side than the path length zero interval Each reflected wave data P _{n at the} measurement position Xn is divided.

That is, dividing each reflected wave data P _n obtained in step S100 to the respective reflected wave data P _n of each reflected wave data P _n of the first vehicle section second vehicle sections.

  Here, the number n of the measurement position X in the first and second vehicle sections can be set as in the following Equation 1.

n = Startflag to Endflag (Equation 1)
Here, flag is flag data indicating the number of the vehicle section, and a value of 1 or 2 is set. That is, one of the first and second vehicle sections is selected according to the set value of the flag data flag.

  Therefore, when 1 is set in the flag data flag, the number n (= Start1 to End1) of the measurement position X in the first vehicle section can be represented as the number n of the measurement position X. Start1 is the minimum value of the number n of the first vehicle section, and is the number n of the measurement position X on the rear side in the traveling direction in the first vehicle section. End1 is the maximum value of the number n of the first vehicle section, and is the number n of the measurement position X on the front side in the traveling direction in the first vehicle section. On the other hand, when 2 is set in the flag data flag, the number n (= Start 2 to End 2) of the measurement position X of the second vehicle section can be represented as the number n of the measurement position X. Start2 is the minimum value of the number n of the second vehicle section, and is the number n of the measurement position X on the rear side in the traveling direction in the second vehicle section. End2 is the maximum value of the number n of the second vehicle section, and is the number n of the measurement position X on the front side in the traveling direction in the second vehicle section.

  In the next step S130, 1 is set to the flag data flag, and the count value n of the first counter is set to (Start1 + 1). The first counter is a counter that counts the number n of the measurement position. That is, a value (Start1 + 1) obtained by adding “1” to the minimum value (Start1) of the number of the first vehicle section is set as the count value n of the first counter.

  In the next step S140, the foremost end F1 in the traveling direction in the first vehicle section corresponding to the flag data flag (= 1) in the first and second vehicle sections is obtained. The end F1 is a front detection point where the maximum value of XSn (X coordinate value) for each detection point in the first vehicle section is the X coordinate value, as will be described later. Details of the processing in step S140 will be described below with reference to FIG.

In step S200 (third detection point calculation means) in FIG. 6, the position information (XSn) of the detection point of the exploration wave based on the reflection time of the first peak described above using the path lengths L _n and L _n−1. , YSn) is obtained by triangulation.

Path length L _n is the path length of the measurement positions Xn corresponding to the count value n (= Start1 + 1). The path length L _n-1 is the path length of the measurement position Xn−1 having the number n, which is one smaller than the count value n (= Start1 + 1).

Specifically, in step S200, the position information of the measurement position Xn corresponding to the count value n, the position information of the measurement position X (n-1) of the number (n-1) smaller than the count value n, path length L _n, L _n-1 and the position information of the detected points using (XSn, YSn) will be obtained. The detection point corresponds to a third detection point in the claims.

The triangulation in this embodiment is a first circle drawn with the path length L _n as the radius around the measurement position Xn, and the path length L _n-1 around the measurement position X (n−1) as the radius. When a circle of 2 is drawn, the intersection of the first circle and the second circle is obtained as a detection point.

  Here, the detection point is a part that is estimated as a reflection point where the exploration wave from the transmitter of the distance measuring sensor 10 is reflected by one of the parked vehicles 50 and 51. In the present embodiment, the traveling direction of the vehicle 40 is the X direction, and the direction orthogonal to the X direction is the Y direction (see FIG. 2). XSn is the X coordinate value of the detection point, and YSn is the Y coordinate value of the detection point.

  In the next step S210, it is determined whether or not the count value n of the first counter is End1 (denoted as EndFlag in the drawing). Since Flag is 1 as described above, EndFlag in the figure means End1. End1 is the maximum value of the number n of the measurement position X in the first vehicle section. Here, when the count value n of the first counter has not reached End1, NO is determined. Accordingly, in step S220, the count value n of the first counter is incremented by one. Thereafter, the process returns to step S200.

For this reason, the position information of the measurement position Xn corresponding to the count value n incremented in step S220 and the position information of the measurement position X (n−1) of the number (n−1) smaller than the count value n The position information of the detection point is obtained by triangulation using the path lengths L _n and L _n−1 .

Thereafter, until the count value n of the first counter reaches End1, the NO determination in step S210, the increment of the count value n of the first counter in step S220, and the path lengths L _n and L _{n− in} step S200. The calculation of the position information of the detection point using ₁ is repeatedly obtained. That is, the determining until the count value n of the first counter reaches End1, the path length L _n, the position information of the detection point with L _n-1 for each measurement position Xn.

Thereafter, when the count value n of the first counter reaches End1, YES is determined in step S210. Accordingly, in step S230, it is determined whether or not the set value of the flag data flag is 1. When the set value of the flag data flag is 1, YES is determined in step S230. Along with this, in step S240 ( front detection point calculation means ), the maximum value Max is obtained from XSn (value of the X coordinate) for each detection point of the first vehicle section. As a result, the extreme end point F1 as the second detection point having the maximum value Max as the value of the X coordinate can be obtained.

  In the next steps S250 to S270, Edge1 is set as the count value n in the first counter. Nedge1 is the number of the measurement position closest to the end point F1 on the front side in the vehicle traveling direction from the end point F1 among the measurement positions Xn of the first vehicle section.

  Specifically, in step S250, the count value n of the first counter is set to Start1. As described above, Start1 is the minimum value of the number n of the measurement position X in the first vehicle section.

  Next, in step S260, the X coordinate value (denoted by x in the figure) of the measurement position Xn corresponding to the set count value n (= Start1) is the maximum value Max (the X coordinate value of the extreme end point F1). Determine if greater than. That is, it is determined whether or not the measurement position Xn is located on the front side in the traveling direction with respect to the end point F1. At this time, when the value of the X coordinate of the measurement position Xn corresponding to the count value n is smaller than the maximum value Max, NO is determined in step S260.

  Accordingly, in step S270, the count value n of the first counter is incremented by one. Then, the process proceeds to step S260 again, and it is determined whether or not the value of the X coordinate of the measurement position Xn corresponding to the incremented count value n is larger than the maximum value Max.

  Thereafter, the NO determination in step S260 and the increment of the count value n in step S260 are repeated until the value of the X coordinate of the measurement position Xn becomes larger than the maximum value Max. That is, the count value n is incremented until it is determined as YES in Step S260. Then, when the value of the X coordinate of the measurement position Xn becomes larger than the maximum value Max, it is determined as YES in Step S260. At this time, the above-mentioned Nedge 1 is set as the count value n in the first counter.

  Next, the process proceeds to step S150 in FIG. The vehicle end F is a front end portion of the vehicle 50 in the vehicle traveling direction. Details of the processing in step 150 will be described below with reference to FIGS.

  In step S400 of FIG. 7, the register XS3 is initialized. The register XS3 is a register for storing an integral value of an X coordinate value (XS2n) of a detection point described later.

In the next step S410, the path lengths L2 _m and _n are obtained for each peak from the reflection times of the second and subsequent peaks. The path lengths L2 _m and _n correspond to the second path length in the claims. m is a peak number (peak number) having a minimum value of 2 and a maximum value of M. The path lengths L2 _m and _n are half the value obtained by multiplying the reflection time of the m-th peak by the speed of sound at the measurement position Xn. Note that step S410 constitutes a first path length calculation unit and a second path length calculation unit.

  Here, the second and subsequent peaks are peaks that occur after the first peak timing in the signal level of the received signal. That is, the second and subsequent peaks are the second peak, the third peak,... (M−1) th peak, the Mth peak generated in the signal level of the received signal after transmission of the exploration wave. One of these peaks. In the present embodiment, the second peak, the third peak,... (M−1) th peak, and the Mth peak are referred to as a second peak, a third peak,.

  The second and subsequent peak reflection times are reflection times with the second and subsequent peak timings as reception timings. For example, the reflection time of the m-th (≧ 2) peak is a reflection time having the reception timing as the timing of the m-th peak in the signal level of the received signal after transmission of the search wave, and transmits the search wave. It is the time from the beginning to the timing of the mth peak.

For this reason, the value is calculated | required for every peak as reflection time of the peak after the 2nd. As a result, the path lengths L2 _m and _n are obtained for each peak number from the reflection times of the second and subsequent peaks. That is, in step S410, the path lengths L22, _n , L23, _n , L24, _n ,... L2 _M- 1 at a plurality of measurement positions Xn (rear measurement positions) where Nedge1 ≦ n ≦ End1. , _N , L2 _M , _n are obtained.

  In the next step S420, it is determined whether or not the set value of the flag data flag is 1. When the set value of the flag data flag is 1, YES is determined in step S420. Next, in step S430, it is determined whether or not the count value n of the first counter is End1. If the count value n of the first counter is not End1, NO is determined in step S430. Accordingly, in the next step S440, the count value n of the first counter is incremented by one.

Thereafter, the process returns to step S410, and the path length L2 _m , _{n is obtained} for each peak from the reflection time of the second and subsequent peaks at the measurement position Xn with respect to the incremented count value n.

After that, as long as the set value of the flag data flag is 1 and the count value n of the first counter is kept smaller than End1, the determination in step S420 is YES, the determination in step S430 is NO, the count value n in step S440 And the calculation of the path lengths L2 _m and _n in step S410 is repeatedly performed.

Thus, the path lengths L2 _m and _n are calculated for each peak at a plurality of measurement positions Xn. In other words, the path length _{L22, n, L23, n,} ··· L2 M, n is calculated for each measurement position Xn.

  Then, in step S450, the initial value q of the peak number is set to 2 (q = 2), the count value n of the first counter is set to Nedge1, and the count value of the second counter that counts the variable i is set to Set to zero (= 0). The variable i is a variable for increasing the peak number as will be described later.

In the next step S460, to the path length L2 _q, n is the path length D _n. Here, in step S440, q is set to 2 and Nedge1 is set as the count value n of the first counter. Therefore, in this step S450, the path length L22 and _Nedge1 are _set to the path length _DNedge1. .

In the next step S470 (second route length selection means), it is determined whether or not the route lengths L2 _{q + i} and _{n + 1} are larger than the route lengths L2 _q and _n . The path lengths L2 _{q + i} and _{n + 1} are path lengths obtained based on the reflection time of the q + i-th peak at the measurement position Xn + 1.

Here, in this step S470, since q = 2, n = Nedge1, and i = 0, it is determined whether or not the path length L22, _{Nedge1 + 1} is larger than the path length L22, _Nedge1 . If the path length L22, _{Nedge1 + 1} is smaller than the path length _L222 , _Nedge1 , NO is determined in step S470.

  In the next step S480, it is determined whether q + i + 1 is equal to the maximum value M of the peak number. q + i + 1 is a peak number corresponding to m, and is a value obtained by adding the initial value q of the peak number and the count value i and 1 of the second counter.

  When q + i + 1 is equal to the maximum value M of the peak number, “YES” is determined in the step S480, and the process proceeds to the step S540. On the other hand, when q + i + 1 is smaller than the maximum value M of the peak number, NO is determined in step S480.

  Accordingly, in step S490, the count value i of the second counter is incremented by 1 (i = i + 1). Along with this, the count value i of the second counter becomes 1.

Determining Thereafter, the flow returns to step S470, the path length L2 q _{+ i} corresponding to the count value i of the second counter that this increment, n _{+ 1} is the path length L2 _q, a greater or not than _n.

Here, since q = 2 and i = 1, it is determined in this step S470 whether or not the path length _{L2 3} and _{Nedge1 + 1} are larger than the path length L22 and _Nedge1 .

Thereafter, as long as it is determined that q + i + 1 is smaller than the maximum value M of the peak number and that the path lengths L2 _{q + i} and _{n + 1} are smaller than the path lengths L2 _q and _n , the determination in step S470 is NO and the determination in step S480 is NO The determination and the increment of variable i in step S490 are repeated. Thereafter, when q + i + 1 is smaller than the maximum value M of the peak numbers and the path lengths L2 _{q + i} and _{n + 1} are larger than the path lengths L2 _q and _n , it is determined as YES in step S470. Accordingly, the process proceeds to step S500 in FIG. 8, and the path lengths L2 _{q + i} and _{n + 1} determined as YES in step S470 are set as the path length D _{n + 1} .

In the next step S510 (second detection point calculation means) obtains the position information of the detection point by triangulation using a path length D _{n + 1} and the path length D _n (XS2n, YS2n). The detection point is a second detection point estimated as a reflection point at which the exploration wave from the transmitter of the distance measuring sensor 10 is reflected at the front end portion in the traveling direction of the parked vehicle 50.

Specifically, in step S510, triangulation using the position information of the path length D _{n + 1,} D _n, the measurement position n of the path length D _{n + 1} of the position information of the measuring position n + 1, and path length D _n Thus, the position information (XS2n, YS2n) of the detection point is obtained. XS2n is the X coordinate value of the detection point, and YS2n is the Y coordinate value of the detection point.

  Here, as a detection point, it is used in order to obtain | require the positional information on the advancing direction front side edge part (henceforth the vehicle end F) of the parked vehicle 50. FIG. If the position accuracy of the detection point is low, the position information of the vehicle end F cannot be obtained with high accuracy.

  Therefore, in order to obtain the position information of the vehicle end F with high accuracy, in the next step S520 (second detection point selection means), detection is performed by determining whether or not the detection point is within a predetermined range. It is determined whether or not the point position accuracy is greater than or equal to a predetermined value. Specifically, it is determined whether XS2n is larger than Max and XS2n is smaller than (Max + ΔX). As described above, Max is the value of the X coordinate of the extreme end F1 of the first vehicle section. ΔX is a value determined in advance in order to determine a predetermined X-coordinate value to be described later. The X direction is the vehicle traveling direction as described above. That is, in step S510, it is determined whether or not the detection point is located on the front side in the vehicle traveling direction with respect to the endmost portion F1 and on the rear side in the vehicle traveling direction with respect to the predetermined position. It is determined whether or not the vehicle is within a predetermined range in front of the vehicle traveling direction from F1. The X coordinate value of the predetermined position is (Max + ΔX), and the Y coordinate value of the predetermined position is the same as the Y coordinate value of the extreme end F1.

  Here, when XS2n is a value smaller than Max (XS2n <Max), or when XS2n is larger than (Max + ΔX) (XS2n> (Max + ΔX)), it is determined as NO in step S520, and the process proceeds to step S540. move on.

  On the other hand, when XS2n is larger than Max and XS2n is smaller than (Max + ΔX), the detection point is located on the front side in the vehicle traveling direction from the end F1, and on the rear side in the vehicle traveling direction from the predetermined position. As a result, YES is determined in step S520.

  Accordingly, in step S530, the integral value (= ΣXS2n) of XS2n obtained every time YES is determined in step S520 is stored in the register XS3n.

  Here, step S520 is repeatedly performed as long as NO is determined in step S540, as will be described later. For this reason, when YES is determined in step S510 a plurality of times, a plurality of XS2n are obtained. Therefore, a value obtained by adding a plurality of XS2n is obtained as an integral value. On the other hand, since step S530 of this time is the first step S520 after the execution of the parking space determination process is started, XS2n determined as YES in step S510 is set as an integral value.

  In the next step S540, it is determined whether or not n + 1 matches End1. n + 1 is the number of the measurement position X in the first vehicle section, and is a value obtained by adding 1 to the count value n of the first counter. End1 is the maximum value of the number of the measurement position X in the first vehicle section. When n + 1 is smaller than End1, NO is determined in the step S540.

  In the next step S550, the counter value n of the first counter is incremented by 1, and the counter value i of the second counter is set to zero (i = 0).

Then it returns to step S460 of FIG. 7, the incremented path length L2 _q corresponding to the counter value n of the first counter, _n is a path length D _n. Thereafter, as described above, as long as it is determined that m + i + 1 is smaller than the maximum value M of the peak number and the path lengths L2 _{q + i} and _{n + 1} are smaller than the path lengths L2 _m and _n , the NO determination in step S470. , NO determination in step S480 and increment of variable i in step S490 are repeated. Thereafter, when m + i + 1 is smaller than the maximum value M of the peak number and the paths L2 _{q + i} and _{n + 1} are larger than the path length L2 _q and _n , YES is determined in step S470.

Accordingly, in step S500, the path lengths L2 _{q + i} and _{n + 1} are set as the path length D _{n + 1} . At next step S510, it obtains the positional information of the detection point by triangulation (XS2n, YS2n) using a path length D _{n +} 1, D _n. For this reason, a detection point is calculated | required for every measurement position Xn by step S460, S470, S480, S490, S500, S510.

  If it is determined that the detection point is located on the front side in the vehicle traveling direction from the end F1, and on the rear side in the vehicle traveling direction from the predetermined position determined by (Max + ΔX), YES is determined in step S520. Accordingly, an integral value of XS2n is obtained in step S530. Specifically, an addition value obtained by adding XS2n obtained in the current step S530 to the integration value calculated in the previous step S530 is stored in the register XS3 as the current integration value.

  In the next step S540, when n + 1 is smaller than End1, NO is determined in step S540. Thereafter, steps S550, S460, S470, S480, S490, S500, S510, S520, S530, and S540 are repeated until n + 1 matches End1 and YES is determined in step S540.

  Accordingly, an integral value (= ΣXS2n) of XS2n obtained every time YES is determined in step S520, is stored in the register XS3. If n + 1 becomes equal to End1, YES is determined in the step S540.

  Accordingly, in step S560 (second average value calculation means), the integral value stored in the register XS3 is divided by the number of XS2n to calculate the average value of XS2n. The average value is the value of the X coordinate value of the vehicle end F described above.

  In the next step S160 in FIG. 5, it is determined whether or not the set value of the flag data flag is 2. If it is determined that the setting value of the flag data flag is 1 and NO is determined in step S160, 2 is set in the flag data flag and the count value n of the first counter is set to (Start2 + 1) in the next step S180. That is, a value (Start2 + 1) obtained by adding “1” to the minimum value (Start2) of the second vehicle section number is set as the count value n of the first counter.

  Thereafter, the process returns to step 140, and processing for calculating the value of the X coordinate of the rearmost end point R2 in the traveling direction in the second vehicle section is executed.

  The extreme end point R2 is a rear detection point in the second vehicle section where the minimum value Min of XSn (X coordinate value) for each detection point is the X coordinate value. Hereinafter, step 140 will be described with reference to FIG. The flowchart in FIG. 6 shows the details of the processing in step 140.

First, in step S200 of FIG. 6, as described above, the position information of the measurement position Xn corresponding to the count value n (= Start2 + 1) of the first counter and the number (n−1) that is one smaller than the count value n. obtaining of the position information of the measurement position X (n-1), the path length L _n, position information of the detection point by triangulation using the _{L n-1 (XSn, YSn} ) a. The detection point is a part that is estimated as a reflection point at which the exploration wave from the transmitter of the distance measuring sensor 10 is reflected by the parked vehicle 51.

In the next step S210, when the count value n of the first counter has not reached End2 (denoted as EndFlag in FIG. 6), NO is determined. In addition, since Flag is 2, EndFlag in the figure means End2. In step S220, the count value n of the first counter is incremented by one. Thereafter, the flow returns to step S200, the path length L _n, the position information of the detection point using L _n-1 determined by triangulation.

  Thereafter, until the count value n of the first counter reaches End2 and it is determined YES in step S210, the NO determination in step S210, the increment of the count value n of the first counter in step S220, and the step S200 The calculation of the position information of the detection point at is repeatedly performed.

Thereafter, when the count value n of the first counter reaches End2, YES is determined in step S210. Accordingly, in step S230, it is determined NO because the set value of the flag data flag is 2 instead of 1. Along with this. In step S280 ( rear detection point calculation means ), the minimum value Min is obtained from XSn (X coordinate value) for each detection point of the second vehicle section. Thus, the extreme end point R2 as the first detection point having the minimum value Min as the X coordinate value is obtained.

  In the next steps S290 to S310, Nedge2 is stored in the first counter as the count value n. Nedge2 is the number of the measurement position closest to the end point R2 on the rear side in the vehicle traveling direction from the end point R2 among the measurement positions Xn of the second vehicle section.

  Specifically, in step S290, the count value n of the first counter is set to End2. As described above, End2 is the maximum value of the number n of the measurement position X in the second vehicle section.

  Next, in step S300, the X coordinate value (denoted by x in the figure) of the measurement position Xn corresponding to the set count value n (= End2) is the minimum value Min (the X coordinate value of the extreme end point R2). Judge whether it is smaller or not. That is, it is determined whether or not the measurement position Xn is located behind the extreme end point F1 in the traveling direction.

  At this time, when the value of the X coordinate of the measurement position Xn corresponding to the count value n is larger than the minimum value Min, NO is determined in step S300. Accordingly, in step S310, the count value n of the first counter is decremented by one, and the process proceeds to step S300 again.

  Thereafter, the NO determination in step S300 and the decrement of the count value n in step S310 are repeated until the value of the X coordinate of the measurement position Xn becomes smaller than the minimum value Min. Thereafter, when the value of the X coordinate of the measurement position Xn becomes smaller than the minimum value Min, YES is determined in step S300. At this time, Nedge2 is set as the count value n in the first counter.

  Next, the process proceeds to step S150 in FIG. The vehicle end R is a rear end portion of the parked vehicle 51 in the vehicle traveling direction. Although the vehicle end R and the vehicle end F have different positions in the parked vehicle, the calculation process of the vehicle end R is substantially the same as the calculation process of the vehicle end F. Hereinafter, an outline of the calculation process of the vehicle end R will be described with reference to FIGS. 7 and 8.

  First, in step S400 of FIG. 7, after the register XS3 is initialized, the NO determination of step S410, step S420, the NO determination of step S430a, and step S440 until the count value n of the first counter reaches End2. repeat.

  Here, steps S400, S410, S420, S430a, and S440 correspond to steps S400, S410, S420, S430, and S440 in the calculation process of the vehicle end F described above. Step S430a corresponds to step S430, and is a step of determining whether or not the count value n of the first counter has reached End2. Note that steps S400, S410, S430, and S440 have been described in the above-described calculation process of the vehicle end R, and thus description thereof is omitted.

Through the processes of steps S400, S410, S420, S430a, and S440, the path length L2 _m , _n is calculated from the reflection time of the second and subsequent peaks until the count value n of the first counter reaches End2 from Nedge2. Is calculated for each peak. In other words, the path lengths L2 _m and _n are calculated for each peak at a plurality of measurement positions Xn where Start2 ≦ n ≦ Nedge2. The path lengths L2 _m and _n correspond to the second path length in the claims. As described above, m is a peak number having a minimum value of 2 and a maximum value of M.

Next, in step S450a, the initial value q of the peak number is set to 2, the count value n of the first counter is set to Nedge2, the count value i of the second counter is set to zero, and then the next step S460a. in, that the path length L2 _{q, n is} the path length D _n.

Next, the peak number "q + i + 1" is smaller than the maximum value M of the peak number, and the path length L2 _{q +} 1, as long as _{the Nedge2-1} is determined to be smaller than the path length L2 _{q, Nedge2,} step S470a, NO in S480a The determination and step S490a are repeated.

  Here, steps S470a, S480a, and S490a correspond to steps S470, S480, and S490 in the calculation process of the vehicle end F described above.

Step S470a (second path length selection means) is a step of determining whether the path length L2 q _{+ i, n-1} is greater than the path length L2 _{q, n.} The path lengths L2 _{q + i} and _n−1 are path lengths obtained based on the reflection time of the q + i-th peak at the measurement position n−1. Step S480a is a step for determining whether or not q + i + 1 is equal to the maximum value M, as in step S480. Step S490a is a step of incrementing the count value n of the first counter, similarly to step S490.

Such steps S470a, S480a, after repeating the processes of S490a, when the path length L2 _{q +} i, _n-1 is determined to be YES in Step S470a and greater than the path length L2 _{q, n,} the following In step S500a in FIG. 8, route lengths L2 _{q + i} and _n−1 determined as YES in step S470a are defined as route length D _n−1 .

In the next step S510a (first detection point calculation means), the path lengths D _n-1 and D _n , the position information of the measurement position n-1 of the path length D _{n-1 and} the measurement position n of the path length D _n are measured. The position information (XS2n, YS2n) of the detection point is obtained by triangulation using the position information. The detection point is a first detection point estimated as a reflection point at which the exploration wave from the transmitter of the distance measuring sensor 10 is reflected at the rear end portion in the traveling direction of the parked vehicle 51.

  In the next step S520a (first detection point selection means), as in step S520, in order to determine whether or not the position accuracy of the detection point is greater than or equal to a predetermined value, XS2n is smaller than Min and XS2n Is greater than (Min−ΔX). As described above, Min is the value of the X coordinate of the end portion R2 of the second vehicle section. ΔX is a predetermined value for determining a predetermined X coordinate value. That is, in step S520a, in order to determine whether or not the detection point (XS2n, YS2n) is within a predetermined range, the vehicle travels behind the end portion F1 in the vehicle traveling direction and beyond the predetermined position. It is determined whether or not it is located on the front side in the direction. The X coordinate value of the predetermined position is (Max−ΔX), and the Y coordinate value of the predetermined position is the same as the Y coordinate value of the extreme end R2.

  Here, when XS2n is smaller than Min (XS2n> Min), or when XS2n is smaller than (Max−ΔX) (XS2n <(Max−ΔX)), NO is determined in step S520a. Proceed to step S540a.

  On the other hand, when XS2n is smaller than Min and XS2n is larger than (Min−ΔX), the detection point is on the rear side in the vehicle traveling direction with respect to the end portion R2, and on the front side in the vehicle traveling direction with respect to the predetermined position. If it is located, YES is determined in step S520a.

  Accordingly, in step S530a, the integral value (= ΣXS2n) of XS2n obtained every time YES is determined in step S520 is stored in the register XS3n. Since step S530a this time is the first step S530a after the execution of the parking space determination process is started, XS2n determined as YES in step S520a is set as an integral value.

  In the next step S540a, it is determined whether n−1 matches Start2. n-1 is the number of the measurement position X in the second vehicle section, and is a value obtained by subtracting 1 from the count value n of the first counter. Start2 is the minimum value of the number of the measurement position X in the second vehicle section. When n-1 is larger than Start2, NO is determined in step S540a. In the next step S550a, the counter value n of the first counter is decremented by 1, and the counter value i of the second counter is set to zero.

  Such steps S550a, S460a, S470a, S480a, S490a, S500a, S510a, S520a, S530a, and S540a are repeated until n-1 matches End2 and YES is determined in step S540a.

Accordingly, position information (XS2n, YS2n) of the detection points is calculated for each measurement position Xn by triangulation using the path lengths D _n−1 and D _n . If it is determined that the detection point is located on the rear side in the vehicle traveling direction from the end R2 and on the front side in the vehicle traveling direction from the predetermined position determined by (Min−ΔX), YES is determined in step S520a. Accordingly, an integral value (= ΣXS2n) of XS2n obtained every time YES is determined in step S520a is calculated and stored in the register XS3n. In the next step S540a, YES is determined when n-1 matches Start2. Along with this, in step S560a (first average value calculation means), the integral value stored in the register XS3 is divided by the number u2 of XS2n to calculate the average value of XS2n. The number u2 of XS2n is also the number of times YES is determined in step 520a. The average value of XS2n calculated in this way is the value of the X coordinate of the vehicle end R.

  Next, in step S160 in FIG. 5, it is determined that the setting value of the flag data flag is 2, and the process proceeds to the next step S170 (determining means) to determine the X coordinate value of the vehicle end F and the vehicle end R. A parking space is set from the value of the X coordinate (see FIG. 9). In the parking space, the X coordinate value of the rear end of the vehicle traveling direction is the value of the X coordinate of the vehicle end F, and the X coordinate value of the front end of the parking space in the vehicle traveling direction is the X coordinate of the vehicle end R. Is the value of.

According to the present embodiment described above, the parking assist ECU 13 is the rear side in the traveling direction among the plurality of measurement positions Xn (Start2 ≦ n ≦ End2) corresponding to the parked vehicle 51 on the front side in the traveling direction among the plurality of measurement positions Xn. At a plurality of measurement positions, the path length L2 based on the time from the transmission of the exploration wave to the reception thereof is defined as the time when the exploration wave reception level reaches the second and subsequent peaks after the exploration wave is transmitted by the distance measuring sensor 10. _m and _n are calculated for each measurement position (step S410). Path length L2 _m for each measurement position where the calculated, any two adjacent measurement positions Xn-1, Xn path length D _n-1, D _n (data pairs) and of the two adjacent measurement of _n A plurality of detection points in the parked vehicle 51 are calculated by triangulation using a plurality of sets of position information of the positions Xn−1 and Xn. The value of the X coordinate of the vehicle end R is calculated as the average value of the calculated X coordinate values (XS2n) of the plurality of detection points.

The parking assist ECU 13 includes a distance measuring sensor at a plurality of measurement positions Xn (Start1 ≦ n ≦ End1) corresponding to the parked vehicle 50 on the rear side in the traveling direction among the plurality of measurement positions Xn. 10, the path length L2 _m and _n of the exploration wave based on the time from the transmission of the exploration wave to the reception is received at the time when the exploration wave reception level reaches the second and subsequent peaks after the exploration wave transmission. To calculate. Path length L2 _m for each measurement position where the calculated, any two adjacent measurement positions Xn of _n, Xn + 1 of the path length D _n, D _{n + 1} (data pair) and the two adjacent measurement positions Xn , Xn + 1 position information is used to calculate a plurality of detection points in the parked vehicle 50 by triangulation. The value of the X coordinate of the vehicle end F is calculated as the average value of the calculated X coordinate values (XS2n) of the plurality of detection points. And parking assistance ECU13 determines the parking space between the parked vehicles 50 and 51 based on the value of the X coordinate of the vehicle end F in the parked vehicle 50, and the value of the X coordinate of the vehicle end R in the parked vehicle 51.

Here, the path length D _n (D _{n + 1} ) is the time at which the exploration wave reception level reaches the second and subsequent peaks (see P2 in FIG. 10) after the exploration wave is transmitted by the distance measuring sensor 10. Is calculated as follows. The path length D _n (D _{n + 1} ) is the path length La (see FIG. 10) of the exploration wave calculated when the reception time of the exploration wave first reaches the peak (see P1 in FIG. 10). Compared to a long one. Reference numerals 50a and 50b in FIG. 10 indicate detection points, respectively.

Since a detection point with high accuracy is calculated for the vehicle end F of the parked vehicle 50 using such a path length D _n (D _{n + 1} ), a detection point with high accuracy for the vehicle end F is calculated. be able to. Thereby, the value (position information) of the X coordinate of the vehicle end F of the parked vehicle 50 can be obtained with high accuracy.

Similarly, the vehicle end R of the parked vehicle 50 is calculated using the path length D _n (D _n-1 ). For this reason, the value (position information) of the X coordinate of the vehicle end R of the parked vehicle 51 can be obtained with high accuracy.

  As described above, since the value of the X coordinate of the vehicle end R of the parked vehicle 51 and the value of the X coordinate of the vehicle end F of the parked vehicle 50 can be obtained with high accuracy, the parking space between the parked vehicles 50 and 51 can be determined. It can be determined with high accuracy.

In the present embodiment, the parking assist ECU 13 calculates a plurality of detection points (that is, a detection point sequence) in the parked vehicle 50 using a plurality of sets of route lengths D _{n + 1} and D _n as described above, and this calculation The value of the X coordinate of the vehicle end F is calculated as the average value of the X coordinate values (XS2n) of the plurality of detected points. For this reason, the position information (the value of the X coordinate) of the vehicle end F can be calculated with high accuracy.

  In the present embodiment, it is assumed that the detection point of the vehicle end F of the parked vehicle 50 falls within the predetermined range. Therefore, the X of the vehicle end F as an average value is obtained using only the values of the X coordinates of a plurality of detection points that satisfy the condition (YES in step S520) that is greater than Max and smaller than the predetermined value (Max + ΔX). Calculate the coordinate value. For this reason, the value of the X coordinate of the vehicle end F can be obtained with high accuracy.

Further, as described above, the parking assist ECU 13 calculates a plurality of detection points (that is, a detection point sequence) in the parked vehicle 51 using a plurality of sets of route lengths D _n−1 and D _n , and the calculated plurality of points. The value of the X coordinate of the vehicle end R is calculated as the average value of the X coordinate values (XS2n) of the detected points. For this reason, the position information (X coordinate value) of the vehicle end R can be calculated with high accuracy.

  In the present embodiment, it is assumed that the detection point of the vehicle end R of the parked vehicle 51 falls within the predetermined range. Therefore, the vehicle end R as an average value is calculated using only the X coordinate values of a plurality of detection points that satisfy the condition (YES in step S520a) that is smaller than Min and larger than a predetermined value (Min−ΔX). The value of the X coordinate is calculated. For this reason, the value of the X coordinate of the vehicle end R can be obtained with high accuracy.

In the present embodiment, the parking assist ECU 13 determines the measurement position Xn on the rear side in the traveling direction when calculating the path lengths D _n and D _{n + 1} for calculating the value of the X coordinate of the vehicle end F of the parked vehicle 50. pathlength L2 _q, measurement position in the traveling direction front side than the _n Xn + 1 of the path length L2 _{q, n + 1} pair of measurement positions adjacent to be longer Xn, Xn + 1 of the path length _{L2 q, n, L2 q,} n ₊₁ is selected, and a pair of route lengths L2 _q , _n , L2 _q , _{n + 1} is set as a pair of route lengths D _n and D _{n + 1} .

Here, in the parked vehicle 50, on the front side in the traveling direction with respect to the vehicle end F (front end in the traveling direction), the distance between the measuring position Xn and the vehicle end F increases as the measurement position Xn advances toward the front side in the traveling direction. become longer. That is, the distance between the measurement position Xn + 1 and the vehicle end F is longer than the distance between the measurement position Xn and the vehicle end F. Therefore, the path length L2 _{q, n} <path length L2 _{q, n + 1} to become the measurement position Xn, Xn + 1 of the path length _{L2 q, n, L2 q,} n + 1 with a pair of path length D _n, D _{n +} By setting it as ₁ , it can suppress calculating parts other than the vehicle end F of the parked vehicle 50 as a detection point. Thereby, the value of the X coordinate of the vehicle end F in the parked vehicle 50 can be accurately calculated.

In addition to this, on the rear side in the traveling direction with respect to the vehicle end R (the rear end portion in the traveling direction) of the parked vehicle 51, the measurement position Xn and the vehicle end R as the measurement position Xn advances toward the rear side in the traveling direction. The distance between becomes longer. That is, the distance between the measurement position Xn-1 and the vehicle end R is longer than the distance between the measurement position Xn and the vehicle end R. Therefore, the path length L2 _{q, n} <path length L2 _{q, n-1} to become the measurement position Xn, the path length L2 _q of _{Xn-1, n, L2 q} , the _n-1 of the pair path length D _n, D By setting it to _n-1 , it can suppress calculating parts other than the vehicle end R of the parked vehicle 51 as a detection point. Thereby, the value of the X coordinate of the vehicle end R in the parked vehicle 51 can be calculated with high accuracy.

  FIG. 11 shows an actual measurement result of detection points of one parked vehicle 50. In FIG. 11, a thick rectangular frame is the parked vehicle 50, the front-rear direction (vehicle traveling direction) of the parked vehicle 50 is the X direction, and the width direction (left-right direction) of the parked vehicle 50 is the Y direction.

  As can be seen from FIG. 11, detection points based on the reflection times of the third and fourth peaks are calculated in the vicinity of the front end of the parked vehicle 50, and in the vicinity of the rear end of the parked vehicle 50, Detection points based on the reflection time of the fifth peak were respectively calculated.

  FIG. 12 shows an actual measurement result of the positional accuracy of the vehicle end F (referred to as front accuracy in FIG. 12) and an actual measurement result of the positional accuracy of the vehicle end R (referred to as rear accuracy in FIG. 12). As can be seen from the bar graph of “rear accuracy” in the figure, the detection point calculated based on the reflection time of the first peak at the vehicle end R has a positional error of about 11 cm, whereas The position error of the detection point calculated based on the reflection time of the peak is about 6 cm.

  As can be seen from the bar graph of “front accuracy” in the figure, the detection point calculated based on the reflection time of the first peak at the vehicle end F has a positional error of about 24 cm, whereas The position error of the detection point calculated based on the peak reflection time is about 7 cm.

  Thus, at the vehicle ends R and F, the detection point calculated based on the reflection time of the second peak is more positional error than the detection point calculated based on the reflection time of the first peak. Is small and high in accuracy.

(Second Embodiment)
In the first embodiment described above, an example in which Nedge 1 is set as the count value n of the first counter based on the maximum value Max of XSn for each detection point of the first vehicle section has been described. In the second embodiment, an example in which Nedge 1 is set will be described as follows.

  Hereinafter, the parking space determination process of the parking assistance ECU 13 in the present embodiment will be described.

  The parking space determination process of the present embodiment is different from the parking space determination process of the first embodiment described above except that the process of step S140 in FIG. 5 is other processes (steps S100, S110, S120, S130, S150). Is the same as the parking space determination process of the first embodiment described above. Therefore, description of other processes (steps S100,..., S150) is omitted, and details of the process of step S140 of the present embodiment will be described below with reference to FIG. FIG. 13 is a flowchart showing details of the process in step S140 of the present embodiment.

  First, in step S600, it is determined whether or not the set value of the flag data flag is 1. When the set value of the flag data flag is 1, it is determined YES, and the process proceeds to the next step S602, where the count value n of the first counter is set to End1.

In the next step S602, a second derivative L _n (= d ² L _n / dXn ² ) with respect to the measurement position Xn of the path length L _n corresponding to the count value n (= End 1) of the first counter is calculated. The calculated position information and path length L _n of each measurement position Xn of the first vehicle section is used. The second order differential L _n indicates the change rate of the change rate with respect to the measurement position Xn of the path length L _n .

In the next step S603 (rear measurement position selection means), the count value n is set to a range in which the parked vehicle 50 can be detected based on the reflection time of the first peak among the measurement positions Xn of the first vehicle section. In order to determine whether or not the corresponding measurement position Xn is present, it is determined whether or not the second-order differential L _n is less than or _equal to the threshold SLESH. As the threshold SLESH, for example, a positive value close to zero is used.

Here, the X axis indicates the measurement positions Xn, when drawn in the Y-axis X-Y coordinates and the path length L _n of the plurality of detection points as each point, a range in which detection points are arranged in substantially linear first Based on the peak reflection time, the parked vehicle 50 can be detected. For this reason, in step S603, it is determined whether or not the detection point corresponding to the count value n is within the range in which the detection points are arranged substantially linearly in the XY coordinates.

In step S603, if the second derivative L _n is greater than the threshold SLESH the measurement position Xn is measured the position capable of detecting the parked vehicle 50 by the reflection time of the first peak of each measurement position Xn of the first vehicle section In step S603, it is determined as NO.

  In this case, in step S605, the count value n of the first counter is decremented by 1 (n = n−1), and the process proceeds to step S602 again.

At this time, the second-order differential L _n with respect to the measurement position Xn of the path length L _n corresponding to the count value n (= End 1-1) of the first counter is calculated. In the next step S603, it is determined whether or not the second-order differential L _n is not more than the threshold value SLESH.

Thereafter, in step S603, the decrement process in step S605, the second-order derivative calculation process in step S602, and the determination process in step S603 are repeated until the second-order derivative L _n becomes equal to or smaller than the threshold SLESH.

Thereafter, in step S603, if it is determined that the second-order differential L _n is equal to or smaller than the threshold SLESH, and YES is determined, the measurement position Xn corresponding to the second-order differential L _n determined to be YES is set as the measurement position F1 ′ (step S604). . The measurement position F1 ′ is a range in which the parked vehicle 50 can be detected based on the reflection time of the first peak among the measurement positions Xn of the first vehicle section, and is the measurement position on the most front side in the vehicle traveling direction. is there. The measurement position F1 ′ corresponds to a second measurement position described in the claims. In the next step S606, the count value n of the first counter is incremented by 1 (n = n + 1). At this time, Nedge 1 of the present embodiment is set as the count value n in the first counter. Nedge1 is the minimum value of the number of the measurement position Xn for calculating the path length L2 _m , _n of the first vehicle section in step S410 of FIG. Thereafter, the process proceeds to step S150 in FIG.

  Next, an example in which Nudge 1 is set as the count value n in the first counter in the second vehicle section will be described.

  First, in step S600, when the set value of the flag data flag is 2, it is determined as NO, the process proceeds to the next step S610, and the count value n of the first counter is set to Start2.

In the next step S611, a second-order differential L _n (= d ² L _n / dXn ² ) with respect to the measurement position Xn of the path length L _n corresponding to the count value n (= Start ² ) is calculated. The calculated position information and path length L _n of each measurement position Xn of the second vehicle section is used.

In the next step S612 (front measurement position selection means), the measurement position Xn corresponding to the count value n is a measurement that can detect the parked vehicle 51 at the reflection time of the first peak among the measurement positions Xn of the second vehicle section. In order to determine whether or not the position is within the range of the position, it is determined whether or not the second-order differential L _n is equal to or less than the threshold value SLESH.

In step S612, if the second-order differential L _n is greater than the threshold SLESH, NO is determined in step S6612. That is, it is determined that the measurement position Xn corresponding to the count value n is out of the measurement position range in which the parked vehicle 51 can be detected with the reflection time of the first peak among the measurement positions Xn of the second vehicle section. become. In this case, in step S613, the count value n of the first counter is incremented by 1 (n = n + 1), and the process proceeds to step S611 again.

At this time, the second-order differential L _n with respect to the measurement position Xn of the path length L _n corresponding to the count value n (= Start 2 + 1) of the first counter is calculated. In the next step S612, it is determined whether or not the second-order differential L _n is equal to or less than the threshold SLESH.

Thereafter, in step S612, the increment process in step S613, the second-order derivative calculation process in step S611, and the determination process in step S612 are repeated until the second-order derivative L _n becomes equal to or smaller than the threshold SLESH.

Thereafter, in step S612, if it is determined that the second-order differential L _n is equal to or smaller than the threshold SLESH, and YES is determined, the measurement position Xn corresponding to the second-order differential L _n determined to be YES is set as the measurement position R2 ′ (step S614). . The measurement position R2 ′ is a range of measurement positions where the parked vehicle 51 can be detected at the reflection time of the first peak among the measurement positions Xn of the second vehicle section among the measurement positions Xn of the second vehicle section. And the measurement position on the rearmost side in the vehicle traveling direction. The measurement position R2 ′ corresponds to a first measurement position described in the claims. In the next step S615, the count value n of the first counter is decremented by 1 (n = n-1). At this time, Nedge2 of the present embodiment is set as the count value n in the first counter. Nedge2 is the maximum value of the number of measurement positions Xn to calculate the path length L2 _{m, n} of the second vehicle section in step S410 in FIG. Thereafter, the process proceeds to step S150 in FIG.

According to the present embodiment described above, the second-order derivative L _n with respect to the measurement position Xn of the path length L _n of the first vehicle section is calculated for each measurement position Xn, and the second-order derivative L _n is greater than the threshold value SLESH. The count value n of the first counter is decremented by one, and then the decrement process (step S605), the second-order derivative calculation process (step S602), and the determination process until the second-order derivative L _n becomes equal to or smaller than the threshold SLESH. (Step S603) is repeated. In such a process, when it is determined that the second-order differential L _n is equal to or less than the threshold SLESH, if the count value n of the first counter is incremented by one, the count value of the first counter is the same as in the first embodiment. Nedge1 can be set as n.

Further, even when the setting of Nedge2, the second derivative L _n for measuring the position Xn of the path length L _n of the second vehicle section is calculated for each measurement position Xn, if the second derivative L _n is greater than the threshold SLESH is Then, the count value n of the first counter is incremented by one (n = n + 1), and thereafter, increment processing (step S613) and second-order derivative calculation processing (step S613) until the second-order derivative L _n becomes equal to or less than the threshold SLESH. Step S611) and the determination process (Step S612) are repeated. In such a process, after determining that the second-order differential L _n is equal to or less than the threshold SLESH and decrementing the count value n of the first counter by 1 (n = n−1), as in the first embodiment, Nedge 2 can be set as the count value n of the first counter.

(Other embodiments)
In the above-described embodiment, an example in which an ultrasonic wave is used as an exploration wave transmitted and received by the distance measuring sensor 10 is shown, but the present invention is not limited to this, and an electric wave, a sound wave, or the like may be used as the exploration wave.

  In the above-described embodiment, an example in which a parked vehicle is used as an obstacle has been shown, but instead of this, an object (for example, a wall or a fence) other than the parked vehicle may be used as an obstacle.

In the above embodiment, the example has been described in which the detection point having the minimum value Min of the XSn (X coordinate value) for each detection point in the second vehicle section as the X coordinate value is the extreme end point R2. Not only this but the detection point which makes the average value of several XSn of the advancing direction back side (minimum value side) XSn among the XSn for every detection point in a 2nd vehicle area may be made into the end point R2. .

  In the above-described embodiment, the example in which the position where the maximum value is the X coordinate value among the XSn (X coordinate value) of each detection point in the first vehicle section has been described as the end portion F1, is not limited thereto. Alternatively, in the first vehicle section, a detection point having an X coordinate value as an average value of a plurality of XSn on the front side (maximum value side) in the traveling direction among XSn of each detection point may be set as the end point F1.

In the above embodiment, the average value of the X coordinate values (XS2n) of the plurality of detection points in the parked vehicle 50 calculated using a plurality of sets of route lengths D _{n + 1} and D _n is the X coordinate of the vehicle end F. In the example shown here, instead of this, the value of the X coordinate of the vehicle end F is used as the value of the X coordinate of the detection point located closest to the traveling direction among the X coordinate values (XS2n) of the plurality of detection points. It is good.

In the above embodiment, the parking assist ECU 13 calculates the vehicle end F and the vehicle end R after obtaining all the reflected wave data P ₁ , P ₂ , P ₃ ,... P _N−1 , P _N. Although the example which performed the process was shown, instead of this, the parking assistance ECU 13 acquires the reflected wave data P ₁ , P ₂ , P ₃ ,... P _N−1 , P _N , the vehicle end F, and Processing for calculating the vehicle end R may be performed.

In the above embodiment, the average value of the X coordinate values (XS2n) of the plurality of detection points in the parked vehicle 51 is set as the X coordinate value of the vehicle end R using a plurality of sets of route lengths D _n-1 and D _n . Although an example is shown, instead of this, the X coordinate value of the detection point on the rearmost side in the traveling direction among the X coordinate values (XS2n) of the plurality of detection points may be set as the X coordinate value of the vehicle end R. .

DESCRIPTION OF SYMBOLS 1 Parking assistance apparatus 10 Ranging sensor 11 Parking switch 12a Vehicle speed sensor 12b Steering angle sensor 13 Steering angle sensor 30 Steering control ECU
40 Vehicle (own vehicle)
50 parked vehicle 51 parked vehicle

Claims (5)

When the own vehicle moves in the vicinity of the two obstacles (50, 51) arranged in the traveling direction of the own vehicle (40), a search wave is repeatedly transmitted to the two obstacles. Transmission / reception means (10) for receiving a survey wave reflected by one of the two obstacles;
Position detecting means (12a, 12b) for detecting a plurality of measurement positions at which the transmitting / receiving means transmits / receives the exploration wave;
Of the plurality of measurement positions, at the measurement position on the rear side in the traveling direction among the plurality of measurement positions corresponding to the obstacle (51) on the front side in the traveling direction, First path length calculation for calculating the first path length of the exploration wave based on the time from transmission to reception of the exploration wave for the time of reception when the reception level becomes the second or later peak. Means (S410);
Among the plurality of measurement positions, at the measurement position on the front side in the traveling direction among the plurality of measurement positions corresponding to the obstacle (50) on the rear side in the traveling direction, Second path length calculation for calculating the second path length of the exploration wave based on the time from transmission to reception of the exploration wave at the time when the reception level reaches the second and subsequent peaks at the time of reception. Means (S410);
The first path length of the two adjacent measurement positions and the position information of the two adjacent measurement positions among the first path lengths for each of the measurement positions calculated by the first path length calculation means. A first detection point calculation means (S510a) for calculating a first detection point of the exploration wave with respect to the obstacle (51) on the front side in the traveling direction using triangulation;
Among the second path lengths for each of the measurement positions calculated by the second path length calculation means, the second path lengths of the two adjacent measurement positions and the position information of the two adjacent measurement positions And second detection point calculation means (S510) for calculating a second detection point of the exploration wave for the obstacle (50) on the rear side in the traveling direction by triangulation,
Position information of the first detection point of the obstacle ahead of the traveling direction calculated by the first detection point calculating means and the obstacle behind the traveling direction calculated by the second detection point calculating means based of the said positional information of the second detection point, determining means for determining a parking space between the two obstacles and (S170),
At the plurality of measurement positions detected by the position detection unit, the time when the reception level of the reflected wave first peaks after the transmission of the search wave by the transmission / reception unit is defined as the time when the search wave is received. Third path length calculation means (S110) for calculating, for each measurement position, a third path length of the exploration wave based on the time from transmission to reception of
Using the third path length of any two adjacent measurement positions among the plurality of measurement positions detected by the position detection means and a plurality of sets of position information of the two adjacent measurement positions, A third detection point calculating means (S200) for calculating a plurality of third detection points of the exploration wave in the obstacle (50) on the side and the obstacle (51) on the front side in the traveling direction by triangulation;
Rear side detection located on the rear side in the traveling direction among the plurality of third detection points of the exploration wave in the obstacle (51) on the front side in the traveling direction calculated by the third detection point calculating means (S200). Rear detection point calculation means (S280) for obtaining the point (R2);
The front detection point (F1) located on the front side in the traveling direction among the plurality of third detection points of the exploration wave in the obstacle on the rear side in the traveling direction calculated by the third detection point calculating means (S200). Front side detection point calculating means (S240) for obtaining
Of the plurality of measurement positions corresponding to the obstacle (51) on the front side in the traveling direction, a measurement position located on the rear side in the traveling direction from the rear detection point (R2) is used as the first path length calculating means (S410). ) As the measurement position on the rear side in the traveling direction for calculating the first path length, and the front detection point (F1) among the plurality of measurement positions corresponding to the obstacle (50) on the rear side in the traveling direction. The parking position characterized in that the measurement position positioned further forward in the traveling direction is set as the measurement position in the forward direction for calculating the second path length by the second path length calculating means (S410). Spatial detection device. When the own vehicle moves in the vicinity of the two obstacles (50, 51) arranged in the traveling direction of the own vehicle (40), a search wave is repeatedly transmitted to the two obstacles. Transmission / reception means (10) for receiving a survey wave reflected by one of the two obstacles;
Position detecting means (12a, 12b) for detecting a plurality of measurement positions at which the transmitting / receiving means transmits / receives the exploration wave;
Of the plurality of measurement positions, at the measurement position on the rear side in the traveling direction among the plurality of measurement positions corresponding to the obstacle (51) on the front side in the traveling direction, First path length calculation for calculating the first path length of the exploration wave based on the time from transmission to reception of the exploration wave for the time of reception when the reception level becomes the second or later peak. Means (S410);
Among the plurality of measurement positions, at the measurement position on the front side in the traveling direction among the plurality of measurement positions corresponding to the obstacle (50) on the rear side in the traveling direction, Second path length calculation for calculating the second path length of the exploration wave based on the time from transmission to reception of the exploration wave at the time when the reception level reaches the second and subsequent peaks at the time of reception. Means (S410);
The first path length of the two adjacent measurement positions and the position information of the two adjacent measurement positions among the first path lengths for each of the measurement positions calculated by the first path length calculation means. A first detection point calculation means (S510a) for calculating a first detection point of the exploration wave with respect to the obstacle (51) on the front side in the traveling direction using triangulation;
Among the second path lengths for each of the measurement positions calculated by the second path length calculation means, the second path lengths of the two adjacent measurement positions and the position information of the two adjacent measurement positions And second detection point calculation means (S510) for calculating a second detection point of the exploration wave for the obstacle (50) on the rear side in the traveling direction by triangulation,
Position information of the first detection point of the obstacle ahead of the traveling direction calculated by the first detection point calculating means and the obstacle behind the traveling direction calculated by the second detection point calculating means Determination means (S170) for determining a parking space between the two obstacles based on the position information of the second detection point of
At the plurality of measurement positions detected by the position detection unit, the time when the reception level of the reflected wave first peaks after the transmission of the search wave by the transmission / reception unit is defined as the time when the search wave is received. Third path length calculation means (S110) for calculating, for each measurement position, a third path length of the exploration wave based on the time from transmission to reception of
Based on the position information for each measurement position and the third path length for each measurement position, the change ratio (Ln ″) of the change ratio of the third path length to the measurement position is a predetermined value or less. A front measurement position selection means (S612) for selecting a first measurement position (R2 ′) that is the measurement position and is located most rearward in the traveling direction;
Among the plurality of measurement positions, among the plurality of measurement positions corresponding to the obstacle (50) on the rear side in the traveling direction, the change ratio (Ln ″) of the change ratio of the third path length with respect to the measurement position is predetermined. A rear measurement position selection means (S603) for selecting a second measurement position (F1 ′) that is a measurement position that is equal to or less than a value and that is located closest to the front in the traveling direction,
Of the plurality of measurement positions corresponding to the obstacle (51) on the front side in the traveling direction, a measurement position located on the rear side in the traveling direction with respect to the first measurement position (R2 ′) is defined as the first path length calculation unit. (S410) as the measurement position on the rear side in the traveling direction for calculating the first path length,
Of the plurality of measurement positions corresponding to the obstacle (50) on the rear side in the traveling direction, a measurement position located on the front side in the traveling direction with respect to the second measurement position (F1 ′) is calculated as the second path length. A parking space detection device characterized in that the measurement position is a measurement position on the front side in the traveling direction for calculating the second route length by means (S410). Of the first path lengths for each of the measurement positions calculated by the first path length calculation means, the first detection point calculation means performs the first detection of the obstacle (51) on the front side in the traveling direction. First path length selection means (S470a) for selecting the first path lengths of the two adjacent measurement positions used for calculating points;
Of the second path lengths for each of the measurement positions calculated by the second path length calculation means, the second detection point calculation means performs the second of the obstacles (50) on the rear side in the traveling direction. Second path length selection means (S470) for selecting the second path length of the two adjacent measurement positions used when calculating a detection point;
The first path length selection means is configured to detect the two adjacent measurement positions so that the first path length is longer at the measurement position on the rear side in the traveling direction than on the measurement position on the front side in the traveling direction. Selecting the first path length;
The second path length selection means is configured to detect the two adjacent measurement positions so that the second path length is longer at the measurement position on the front side in the traveling direction than on the measurement position on the rear side in the traveling direction. Selecting the second path length;
The first detection point calculation means (S510a) uses the first path lengths of the two adjacent measurement positions selected by the first path length selection means to obstruct the front side in the traveling direction. Calculating a first detection point of the exploration wave in (51);
The second detection point calculation means (S510) uses the second path lengths of the two adjacent measurement positions selected by the second path length selection means to cause an obstacle on the rear side in the traveling direction. The parking space detection device according to claim 1 or 2 , wherein a second detection point of the exploration wave in an object (50) is calculated. When the first detection point calculation means (S510a) calculates a plurality of the first detection points in the obstacle (51) on the front side in the traveling direction, the front side in the traveling direction when the traveling direction is the X direction. The average value of the X-coordinate values at the plurality of first detection points of the obstacle (51) is calculated as position information of the rear end portion in the traveling direction of the obstacle (51) on the front side in the traveling direction. Mean value calculating means (S560a),
When the second detection point calculation means (S510) calculates a plurality of the second detection points in the obstacle (50) on the rear side in the traveling direction, the traveling direction is determined when the traveling direction is the X direction. An average value of X-coordinate values at the plurality of second detection points of the rear obstacle (50) is calculated as position information of a front end portion in the advancing direction of the obstacle (50) in the advancing direction. Second average value calculating means (S560),
The determining means (S170) is based on the average value of the X coordinate values calculated by the first average value calculating means and the average value of the X coordinate values calculated by the second average value calculating means. parking space detecting device according to any one of claims 1 to 3, characterized in that determining of the parking space between two obstacles. A plurality of first detection points that fall within a predetermined range are selected from the plurality of first detection points in the obstacle (51) on the front side in the traveling direction calculated by the first detection point calculation means (S510a). First detection point selection means (S520a) to perform,
A plurality of second detection points that fall within a predetermined range among the plurality of second detection points in the obstacle (50) on the rear side in the traveling direction calculated by the second detection point calculation means (S510). Second detection point selection means (S520) to select,
The first average value calculation means (S560a) calculates an average value of X coordinate values at a plurality of first detection points selected by the first detection point selection means as an obstacle (front side in the traveling direction) 51) as the position information of the rear end portion in the traveling direction of 51),
The second average value calculation means (S560) calculates an average value of X coordinate values at a plurality of second detection points selected by the second detection point selection means as an obstacle on the rear side in the traveling direction. The parking space detection device according to claim 4 , wherein the parking space detection device calculates the position information of the front end portion in the traveling direction of (50).

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