JP5843948B1 - Parking assistance device and parking assistance method - Google Patents

Abstract

A parking assistance device and a parking assistance method capable of improving the estimation accuracy of parking space information by accurately estimating the position of a reflection point of an object to be detected by a distance sensor. In a guidance mode state, a reflection point position is newly estimated by one of a two-circle intersection process and a two-circle tangent process according to the part of an object detected by a distance sensor (100). Thus, the parking space information estimated in the search mode state is configured to be corrected. [Selection] Figure 1

Description

  The present invention estimates the parking space information of the own vehicle by estimating the reflection point position when the detection wave emitted from the distance sensor mounted on the own vehicle is reflected on the object, and parking assistance based on the estimation result The present invention relates to a parking support device and a parking support method.

  Conventionally, a parking assistance device for notifying the driver of the own vehicle who wants to park in the parking space existing between the first parked vehicle and the second parked vehicle, whether or not the own vehicle can be parked in the parking space. Has been proposed (see, for example, Patent Document 1).

  The parking assistance apparatus described in Patent Document 1 obtains distance data corresponding to the corner portion of each parked vehicle from a time series of distance data from the vehicle to the parked vehicle measured using a distance sensor mounted on the vehicle. The extracted distance data is subjected to noise processing and data interpolation by curve approximation as data processing.

  Moreover, this parking assistance apparatus estimates the reflection point position of each parked vehicle from the distance data after data processing and the sensor position data indicating the movement locus of the sensor position of the distance sensor. Furthermore, this parking assistance apparatus determines whether or not the own vehicle can be parked in this parking space by estimating the width of the parking space based on the position of the corner portion of each parked vehicle obtained from the estimated reflection point position. .

  Conventionally, after it has been determined that the vehicle can be parked in the parking space, the parking space does not require a steering operation by a driver who wants to park the vehicle in the parking space. In addition, a parking assist device that guides the vehicle by automatic steering has also been proposed (see, for example, Patent Document 2).

Japanese Patent No. 5506803 JP 2009-107529 A

However, the prior art has the following problems.
In the parking assistance devices described in Patent Documents 1 and 2, in order to perform appropriate parking assistance for the driver, the parking space information such as the width of the parking space, the width of the parking space, and the position of the parking space is accurately used. Good estimation is required.

  Here, the conventional technology is configured to estimate the parking space information by estimating the position of the reflection point when the object reflects the detection wave from the distance sensor. Therefore, in order to improve the estimation accuracy of the parking space information, a device for accurately estimating the reflection point position of the parked vehicle is required.

  The present invention has been made to solve the above-described problems, and improves the estimation accuracy of parking space information by accurately estimating the reflection point position of an object that is a detection target of a distance sensor. An object of the present invention is to obtain a parking assist device and a parking assist method.

  The parking assist device according to the present invention irradiates an object to be detected with a detection wave, and obtains a detection wave reflected at a reflection point position on the object corresponding to the shortest distance to the object, thereby obtaining distance data to the object. A distance sensor for detecting the vehicle and a vehicle information sensor for detecting a state relating to the speed and traveling direction of the own vehicle as own vehicle data, while detecting the time series by the distance sensor and the vehicle information sensor while moving the own vehicle. Based on the result, when the operation mode is the search mode, the parking space is estimated to be parked, and when the operation mode is the guidance mode, the guidance support for parking the vehicle in the parking space is performed. A parking assistance device that performs processing, and a reflection point estimation unit that estimates a reflection point position of an object in time series from a time series detection result by a distance sensor and a vehicle information sensor; Using the reflection point position estimated in time series by the point estimation unit, the object information for identifying the position of the object is estimated, and the parking space information for identifying the parking space in which the subject vehicle can be parked using the estimated object information. A parking space estimation unit that estimates the vehicle, a vehicle control unit that performs parking support for parking the vehicle in the parking space according to the parking space information estimated by the parking space estimation unit, and object information estimated by the parking space estimation unit And a reflection part estimation unit that estimates the part of the object detected by the distance sensor in time series while parking assistance is performed by the vehicle control unit from the current position of the host vehicle, and the current time It corresponds to the detection range of the distance sensor defined by the distance data detected by the distance sensor at the current time centering on the position of the distance sensor at The arc is the first arc, and the arc corresponding to the detection range of the distance sensor defined by the distance data detected by the distance sensor at the past time is centered on the position of the distance sensor at the past time before the current time. In the case of two arcs, a method of defining the intersection point of the first arc and the second arc as the reflection point position is defined as a two-circle intersection process, and a common tangent line of the first arc and the second arc is drawn and the second tangent line is in contact with the common tangent line. When the method of setting a contact point on one arc as a reflection point position is defined as a two-circle tangent process, the reflection point estimation unit, when the operation mode is the search mode, at least one of the two-circle intersection process and the two-circle tangent process The position of the reflection point is estimated in time series, and when the operation mode is the guidance mode, it is estimated in time series by the reflection part estimation unit while parking support is performed by the vehicle control unit. Depending on the part of the object detected by the distance sensor, when the object part is a point-shaped part, a two-circle intersection process is used, and when the object part is a surface-shaped part, a two-circle tangent process is used for reflection. The point position is newly estimated in time series. When the operation mode is the guidance mode, the parking space estimation unit newly estimates the object information using the reflection point position newly estimated by the reflection point estimation unit. By doing so, the parking space information is corrected.

  Further, the parking assist method of the present invention irradiates a detection wave to an object to be detected, and obtains a detection wave reflected at a reflection point position on the object corresponding to the shortest distance to the object. A distance sensor for detecting distance data and a vehicle information sensor for detecting a state related to the speed and traveling direction of the own vehicle as own vehicle data, while moving the own vehicle, a time series by the distance sensor and the vehicle information sensor. Based on the detection result, when the operation mode is the search mode, an estimation process of a parking space where the vehicle can be parked is performed, and when the operation mode is the guidance mode, the vehicle is parked in the parking space. A parking support method executed by a parking support device that performs a guidance support process, wherein a reflection point position of an object is determined from a time-series detection result by a distance sensor and a vehicle information sensor. Estimating object information that identifies the position of the object using the reflection point estimation step estimated in time series and the reflection point position estimated in time series in the reflection point estimation step, and using the estimated object information A parking space estimation step for estimating parking space information for identifying a parking space that can be parked, and a vehicle control step for performing parking assistance for parking the vehicle in the parking space according to the parking space information estimated in the parking space estimation step Then, from the object information estimated in the parking space estimation step and the current position of the host vehicle, the part of the object detected by the distance sensor is estimated in time series while parking assistance is performed in the vehicle control step. A reflection site estimation step, wherein the current time is centered on the position of the distance sensor at the current time. The arc corresponding to the detection range of the distance sensor defined by the distance data detected by the distance sensor is the first arc, and the distance sensor at the past time is centered on the position of the distance sensor at the past time before the current time. When the arc corresponding to the detection range of the distance sensor defined by the distance data detected in step 2 is the second arc, the method of setting the intersection of the first arc and the second arc as the reflection point position is a two-circle intersection process. When the method of defining and drawing the common tangent line of the first arc and the second arc and defining the contact point on the first arc in contact with the common tangent as the reflection point position is defined as the two-circle tangent process, When the mode is the search mode, the reflection point position is estimated in time series using at least one of the two-circle intersection process and the two-circle tangent process, and the operation mode is the guidance mode. The part of the object is a point-shaped part according to the part of the object detected by the distance sensor estimated in time series in the reflection part estimation step while parking assistance is performed in the vehicle control step. Sometimes two-circle intersection processing is used, and when the part of the object is a surface shape portion, two-circle tangent processing is used to newly estimate the reflection point position in time series. In the parking space estimation step, the operation mode is guided mode. In this case, the parking space information is corrected by newly estimating the object information using the reflection point position newly estimated in the reflection point estimation step.

  According to the present invention, in the guidance mode state, the reflection point position is newly estimated by one of the two-circle intersection process and the two-circle tangent process according to the part of the object detected by the distance sensor. Thus, the parking space information estimated in the search mode state is configured to be corrected. Thereby, the parking assistance apparatus and the parking assistance method which can improve the estimation precision of parking space information by estimating the reflective point position of the object which is a detection target of a distance sensor accurately can be obtained.

It is a block diagram which shows the structure of the parking assistance system containing the parking assistance apparatus in Embodiment 1 of this invention. It is explanatory drawing which shows an example of the positional relationship at the time of mounting the distance sensor connected to the parking assistance apparatus in Embodiment 1 of this invention in the own vehicle. In the first embodiment of the present invention, when the part of the object detected by the distance sensor is a side surface portion of the parked vehicle, the reflection point position is estimated by the two-circle intersection process and the reflection by the two-circle tangent process It is explanatory drawing compared with the time when a point position is estimated. In Embodiment 1 of the present invention, when the location of the object detected by the distance sensor is on the top viewpoint object, the reflection point position is estimated by the two-circle intersection process, and the reflection point by the two-circle tangent process It is explanatory drawing compared with the time when a position is estimated. In Embodiment 1 of the present invention, when the part of the object detected by the distance sensor is a corner portion of a parked vehicle, the reflection point position is estimated by the two-circle intersection process, and the reflection is performed by the two-circle tangent process. It is explanatory drawing compared with the time when a point position is estimated. In Embodiment 1 of this invention, it is explanatory drawing which shows the mode of a movement of the own vehicle at the time of a driver | operator carrying out parallel parking or parallel parking. In Embodiment 1 of this invention, it is explanatory drawing which shows operation | movement of the parking assistance apparatus at the time of a parking assistance apparatus estimating the parking space information of the own vehicle. It is explanatory drawing which shows operation | movement of the parking assistance apparatus at the time of the own vehicle moving to a parking space from the state of FIG. It is explanatory drawing which shows operation | movement of the parking assistance apparatus when the own vehicle further moves to a parking space from the state of FIG.

  Hereinafter, a parking assistance device and a parking assistance method according to the present invention will be described with reference to the drawings according to a preferred embodiment. In the description of the drawings, the same portions or corresponding portions are denoted by the same reference numerals, and redundant description is omitted.

Embodiment 1 FIG.
FIG. 1 is a block diagram showing a configuration of a parking assistance system including a parking assistance device 300 according to Embodiment 1 of the present invention. FIG. 2 is an explanatory diagram illustrating an example of a positional relationship when the distance sensor 100 connected to the parking assist device 300 according to Embodiment 1 of the present invention is mounted on the host vehicle.

  The parking support system in FIG. 1 includes a distance sensor 100, a vehicle information sensor 200, and a parking support device 300. Here, actually, as shown in FIG. 2, a plurality of distance sensors 100 are mounted on the host vehicle. However, in the first embodiment, the processing of the plurality of distance sensors 100 is the same, One distance sensor 100 will be described.

  The distance sensor 100 irradiates an object to be detected (for example, a parked vehicle) with a detection wave and acquires a detection wave reflected at a reflection point position on the object corresponding to the shortest distance to the object. Detect distance data. Specifically, the distance sensor 100 radiates an ultrasonic wave to an object to be detected, receives an ultrasonic wave reflected from the object, and based on a time difference between the irradiated ultrasonic wave and the received ultrasonic wave. Signal processing is performed, and the distance to the object is detected as distance data. At this time, only the distance to the object can be obtained by the distance sensor 100, and the direction of the object may not be detected. The distance sensor 100 detects the above-described distance data at a preset cycle.

  The distance sensor 100 outputs the detected distance data to the object detection unit 310. The distance data detected by the distance sensor 100 is stored in a storage unit (not shown) in association with the time when the distance data is detected.

  Here, it is assumed that the mounting position of the distance sensor 100 on the vehicle and the sensor orientation information of the distance sensor 100 are already known. This sensor orientation information includes the sensor orientation of the distance sensor 100 and the sensor viewing angle (ie, the detectable orientation width). Hereinafter, the mounting position of the distance sensor 100 on the own vehicle and the sensor orientation information of the distance sensor 100 are collectively referred to as known sensor information.

  Further, as the distance sensor 100, a type of sensor that detects a distance to an object as distance data using a detection wave such as an electromagnetic wave instead of an ultrasonic wave may be used. Furthermore, as the distance sensor 100, specifically, an ultrasonic sensor, a millimeter wave radar, a laser radar, an infrared sensor, an optical camera, or the like can be used.

  The vehicle information sensor 200 is mounted on a vehicle and detects a state relating to the speed and the traveling direction of the own vehicle as own vehicle data. Specifically, the vehicle information sensor 200 detects a state relating to the speed and traveling direction of the own vehicle such as the speed, wheel speed, steering angle, and yaw rate of the own vehicle as own vehicle data. Further, the vehicle information sensor 200 detects the own vehicle data at the previously set cycle.

  The vehicle information sensor 200 outputs the detected own vehicle data to the object detection unit 310. In addition, the host vehicle data detected by the vehicle information sensor 200 is stored in the storage unit in association with the time when the host vehicle data is detected. In addition, you may comprise the vehicle information sensor 200 so that the latitude, the longitude, and the advancing direction of the own vehicle may be detected as own vehicle data using GPS (Global Positioning System).

  The parking assist device 300 includes an object detection unit 310 and a vehicle control unit 320. If the operation mode is the search mode, the parking assistance apparatus 300 performs an estimation process of a parking space where the own vehicle can be parked. That is, when the operation mode is the search mode, the parking assist device 300 estimates the parking space information as the parking space estimation process, and determines whether or not the own vehicle can be parked in the parking space based on the estimation result. .

  In addition, when it is determined that parking is possible in the search mode, the parking support device 300 switches the operation mode from the search mode to the guidance mode, and performs a guidance support process for parking the vehicle in the parking space. That is, when the operation mode is the guidance mode, the parking assistance device 300 performs parking assistance while sequentially correcting the parking space information estimated in the search mode as guidance assistance processing.

  Specifically, the driver who drives the own vehicle activates the parking assist device 300 when the driver wants to park the own vehicle in the parking space. After the activation, the parking assistance device 300 sets the operation mode to the search mode. In this case, the parking assistance device 300 estimates the parking space information, and determines whether or not the own vehicle can be parked in the parking space based on the estimation result. Hereinafter, a state in which the operation mode of the parking assistance apparatus 300 is the search mode is referred to as a “search mode state”.

  Subsequently, when it is determined that parking is possible in the search mode state, the parking assistance device 300 switches the operation mode from the search mode to the guidance mode. In this case, the parking assistance device 300 performs parking assistance while sequentially correcting the parking space information estimated in the search mode. Hereinafter, a state in which the operation mode of the parking assistance device 300 is the guidance mode is referred to as a “guidance mode state”.

  The object detection unit 310 detects the object as the host vehicle moves to the side of the object existing at a position adjacent to the parking space. That is, the object detection unit 310 acquires the time-series detection results by the distance sensor 100 and the vehicle information sensor 200, and estimates the reflection point position of the object that changes in time series from the detection results, so that the position of the object, the object Object information such as the shape of the object, the position of the side surface portion of the object, the position of the corner portion of the object, and the like are estimated.

  Moreover, the object detection part 310 estimates parking space information, such as the width of a parking space, the width of a parking space, the position of a parking space, etc. using the estimated object information. Furthermore, the object detection unit 310 estimates parking space information such as the width of the parking space, the width of the parking space, and the position of the parking space using the estimated object information.

  The object detection unit 310 includes an object classification unit 311, a host vehicle position estimation unit 312, a reflection site estimation unit 313, a reflection point estimation unit 314, and a parking space estimation unit 315.

  The object classification unit 311 accumulates the distance data input from the distance sensor 100 after entering the search mode state or after entering the guidance mode state, and for each distance data estimated as one object. Sort and store each as a distance data string. In addition, although it does not mention here about a specific classification method, the method currently disclosed by patent document 1 may be used, for example, and another well-known method may be used. Further, the object classification unit 311 outputs distance data for each classified object to the reflection point estimation unit 314.

  The own vehicle position estimation unit 312 estimates the position of the own vehicle and the direction of the own vehicle as own vehicle position information from the own vehicle data input from the vehicle information sensor 200, and uses this own vehicle position information as the reflection site estimation unit 313. And output to the reflection point estimation unit 314.

  Although not shown in the figure, the object information estimated by the parking space estimation unit 315 in the search mode state is input to the reflection site estimation unit 313. In the guidance mode state, the reflection site estimation unit 313 includes the vehicle position information input from the vehicle position estimation unit 312, the known sensor information of the distance sensor 100, and the object information estimated in the search mode state. From this, it is estimated which part of the object the distance sensor 100 is detecting, and this estimation result is output to the reflection point estimation unit 314 as reflection part information. That is, the reflection site estimation unit 313 uses the object information estimated in the search mode state to estimate which part of the object the location detected as the shortest distance by the distance sensor 100 in the guidance mode state. The estimated part is output to the reflection point estimation unit 314 as reflection part information.

  On the other hand, in the search mode state, the reflection part estimation unit 313 is in the process of estimating the object information, and has not been completely estimated yet, so the part of the object detected by the distance sensor 100 is estimated. Can not do it. In this case, the reflection site estimation unit 313 outputs information indicating that the site is unknown to the reflection point estimation unit 314 as reflection site information.

  The reflection point estimation unit 314 includes a distance data string for each object input from the object classification unit 311, host vehicle position information input from the host vehicle position estimation unit 312, and a reflection site input from the reflection site estimation unit 313. The position of the reflection point for each object is estimated from the information and the known sensor information of the distance sensor 100, and the estimated reflection point position is output to the parking space estimation unit 315 as reflection point position information.

  In the search mode state, the parking space estimation unit 315 estimates parking space information from the reflection point position information for each object input from the reflection point estimation unit 314 and outputs the parking space information to the vehicle control unit 320. In the guidance mode state, the parking space estimation unit 315 corrects the parking space information estimated in the search mode state from the reflection point position information for each object newly input from the reflection point estimation unit 314. Then, the corrected parking space information is output to the vehicle control unit 320.

  The vehicle control unit 320 determines whether or not the own vehicle can be parked in the parking space based on the parking space information estimated in the search mode state input from the parking space estimation unit 315. Moreover, the vehicle control part 320 alert | reports this determination result to the driver who drives the own vehicle.

  By determining that parking is possible, the vehicle control unit 320 calculates a movement route for the own vehicle to move to the parking space using the estimated parking space information when the search mode state is changed to the guidance mode state. . Specifically, the vehicle control unit 320 calculates a movement route from the positional relationship between the position of the parking space included in the parking space information estimated in the search mode and the current position of the host vehicle.

  The vehicle control unit 320 provides parking assistance so that the vehicle moves to the parking space according to the travel route calculated first. Further, the vehicle control unit 320 corrects the parking space information estimated in the search mode state while the host vehicle is moving according to the travel route calculated first, and newly calculates using the corrected parking space information. Parking assistance is performed according to the travel route.

  As a specific example of parking support by the vehicle control unit 320, the vehicle control unit 320 does not require the driver to perform the steering operation on the assumption that the driver performs the accelerator operation, the brake operation, and the shift operation. Thus, the vehicle can be configured to be controlled. The vehicle control unit 320 can also be configured to control the host vehicle so that the driver does not need to perform at least one of the accelerator operation, the brake operation, and the shift operation in addition to the steering operation. .

  Next, estimation of the reflection point position by the reflection point estimation unit 314 will be described with reference to FIGS. FIG. 3 shows a case where the reflection point position is estimated by the two-circle intersection process when the part of the object detected by the distance sensor 100 is the side surface part of the parked vehicle in the first embodiment of the present invention. It is explanatory drawing which compared with the time of a reflective point position being estimated by circular tangent processing.

  FIG. 4 shows a case where the reflection point position is estimated by the two-circle intersection process when the part of the object detected by the distance sensor 100 is on the top viewpoint object in the first embodiment of the present invention, and two circles. It is explanatory drawing compared with the time when a reflective point position is estimated by a tangent process.

  FIG. 5 shows a case where the reflection point position is estimated by the two-circle intersection process when the part of the object detected by the distance sensor 100 is a corner part of the parked vehicle in the first embodiment of the present invention. It is explanatory drawing which compared with the time of a reflective point position being estimated by circular tangent processing.

  First, each of the two-circle intersection process and the two-circle tangent process, which are methods for estimating the reflection point position, using the distance data detected by the distance sensor 100 will be described.

  As shown in FIG. 3, a case is considered where the distance sensor position, which is the position of the distance sensor 100, is displaced in the direction of the arrow with respect to the parked vehicle as the host vehicle moves.

  In this case, at the current time t, the reflection point position R (t) of the parked vehicle is on the circumference with the distance sensor position as the center and the distance data D (t) detected by the distance sensor 100 at the time t as the radius. Exists somewhere. Further, on such a circumference, the existence range of the reflection point position R (t) is represented by an arc A (t) from the azimuth range defined by the sensor azimuth and sensor viewing angle included in the known sensor information of the distance sensor 100. Can be represented. That is, the reflection point position R (t) exists somewhere on the arc A (t).

  Similar to the time t, the existence range of the reflection point position R (t−Δt) of the parked vehicle at the time t−Δt past the time t can also be represented by the arc A (t−Δt).

  Here, in the two-circle intersection process, it is assumed that the reflection point position of the parked vehicle is substantially the same at time t and time t−Δt.

  Therefore, in the two-circle intersection processing, based on such an assumption, the arc A (t) indicating the existence range of the reflection point position R (t) at time t and the reflection point position R (t−t−) at time t−Δt. The intersection with the arc A (t−Δt) indicating the existence range of Δt) is set as the reflection point position R (t) at time t. In the prior art, the reflection point position of the object at time t is generally estimated only by such a two-circle intersection process described in the present application.

  On the other hand, in the two-circle tangent process, it is noted that the reflection point position actually changes between time t and time t−Δt as the distance sensor position changes between time t and time t−Δt. ing. Therefore, unlike the two-circle intersection process, the two-circle tangent process does not assume that the reflection point position of the parked vehicle is substantially the same at time t and time t−Δt. In addition, the reflection point position of the parked vehicle at each time is the shortest distance point at which the distance from the distance sensor 100 to the object is the shortest, and moves as the distance sensor 100 moves.

  Therefore, in the 2-circular tangent process, an arc A (t) indicating the existence range of the reflection point position R (t) at time t and an arc indicating the existence range of the reflection point position R (t-Δt) at time t−Δt. A common tangent line with A (t−Δt) is drawn, and a contact point on the arc A (t) in contact with the common tangent line is defined as a reflection point position R (t) at time t.

  As described above, two methods of the two-circle intersection process and the two-circle tangent process have been described as the method of estimating the reflection point position of the object using the distance data detected by the distance sensor 100.

  Subsequently, the difference between the accuracy of the reflection point position of the object estimated by the two-circle intersection process and the accuracy of the reflection point position of the object estimated by the two-circle tangent process will be further illustrated in addition to FIGS. This will be described with reference to FIG. FIG. 6 is an explanatory diagram showing the movement of the host vehicle when the driver performs parallel parking or parallel parking in Embodiment 1 of the present invention.

  6A shows the movement of the host vehicle when the parking assistance device 300 is in the search mode state when performing parallel parking, and FIG. 6B shows the parking assistance device 300 when performing parallel parking. The movement of the own vehicle in the guidance mode state is shown. Moreover, FIG.6 (c) shows the movement of the own vehicle when the parking assistance apparatus 300 is a search mode state when performing parallel parking, FIG.6 (d) shows the parking assistance apparatus 300 when performing parallel parking. The movement of the own vehicle when is in the guidance mode state.

  First, as a first example, for example, as shown in FIG. 3, a part of an object detected by the distance sensor 100 whose distance sensor position is displaced in the direction of the arrow as the host vehicle moves becomes a side surface portion of the parked vehicle. Think about the case. The situation in FIG. 3 corresponds to the situation in FIG.

  In such a case, when the trajectory of the plurality of reflection point positions estimated by the two-circle intersection process is compared with the trajectory of the plurality of reflection point positions estimated by the two-circle tangent process, the reflection point position by the two-circle tangent process The trajectory accurately represents the position of the side portion of the parked vehicle (see FIG. 3). Therefore, when the part of the object detected by the distance sensor 100 is a side surface portion of the parked vehicle, it can be said that the reflection point position can be estimated more accurately by the two-circle tangent process than by the two-circle intersection process.

  In particular, in the two-circle intersection process, when the distance between two arcs of the arc A (t) and the arc A (t−Δt) is widened due to the faster movement of the vehicle, the reflection point that is the intersection of the two arcs. The position R (t) moves away from the actual reflection point position. As a result, the estimation accuracy of the reflection point position is deteriorated.

  Therefore, if the part of the object detected by the distance sensor 100 is a surface-shaped portion in this way, the reflection point position can be estimated with higher accuracy by the two-circle tangent process rather than the two-circle intersection process. The same applies to the situation of FIG.

  As a second example, for example, as shown in FIG. 4, a case is considered where the part of the object detected by the distance sensor 100 whose distance sensor position is displaced in the direction of the arrow as the host vehicle moves is on the top viewpoint object. . The top view object here means an object that can be assumed to be a point by relative comparison with the vehicle size when viewed from above. Specific examples of the top view object include an upright pole or a triangular cone. Can be mentioned.

  In such a case, when the reflection point position R (t) estimated at time t estimated by the two-circle intersection process is compared with the reflection point position R (t) estimated at time t by the two-circle tangent process, two circles are obtained. The reflection point position R (t) estimated by the intersection process accurately represents the position of the top viewpoint object (see FIG. 4). Therefore, when the part of the object detected by the distance sensor 100 is on the top viewpoint object, it can be said that the reflection point position can be estimated with higher accuracy in the two-circle intersection process than in the two-circle tangent process.

  Therefore, if the part of the object detected by the distance sensor 100 is a point-shaped portion in this way, the reflection point position can be estimated more accurately by the two-circle intersection process rather than the two-circle tangent process.

  As a third example, for example, as shown in FIG. 5, a case where an object part detected by the distance sensor 100 whose distance sensor position is displaced in the direction of the arrow as the vehicle moves becomes a corner part of the parked vehicle. Think. The situation in FIG. 5 corresponds to the situation in FIG.

  Here, as shown in FIG. 5, when the distance sensor 100 and the corner portion of the parked vehicle face each other and the part of the object detected by the distance sensor 100 becomes the corner portion of the parked vehicle, strictly speaking, Although it depends on the shape of the corner portion, it shows a tendency similar to that of the second example. More specifically, as shown in FIG. 6B, when the parking assist device 300 is in the guidance mode state when performing parallel parking, the own vehicle is moving backward, but the distance sensor 100 The left rear corner of the second parked vehicle is directly facing. In this case, in the two-circle tangent process, the estimation accuracy of the reflection point position may be deteriorated with respect to the two-circle intersection process.

  In such a case, when the reflection point position R (t) estimated at the time t estimated by the two-circle intersection process and the reflection point position R (t) estimated at the time t estimated by the two-circle tangent process are compared, Similar to the example, the reflection point position R (t) estimated by the circle intersection process accurately represents the corner portion of the parked vehicle (see FIG. 5). Therefore, when the part of the object detected by the distance sensor 100 is a corner portion of the parked vehicle, it can be said that the reflection point position can be estimated more accurately in the two-circle intersection process than in the two-circle tangent process.

  Therefore, if the part of the object detected by the distance sensor 100 is a point-shaped portion in this way, the reflection point position can be estimated more accurately by the two-circle tangent process rather than the two-circle intersection process. In addition, as shown in FIG.6 (d), when the parking assistance apparatus 300 is a guidance mode state when carrying out parallel parking, although the own vehicle is moving backward, the distance sensor 100 and the 2nd parked vehicle The left rear corner is directly facing. Even in the situation of FIG. 6D, the same can be said as in FIG.

  As a result of the above consideration, the accuracy of the reflection point position estimated by the two-circle intersection process and the accuracy of the reflection point position estimated by the two-circle tangent process according to the part of the object detected by the distance sensor 100 And found that is different. In other words, the reflection point position can be estimated by the two-circle intersection process in a point-shaped portion where a point that can be regarded as almost the same at the current time and the past time is detected as the shortest distance, such as a corner portion. It is suitable, and the reflection point position can be estimated by the two-circle tangent process in a surface shape portion where a different point separated by a distance equal to or more than the current time and the past time is detected as the shortest distance, such as a side surface portion. I found it suitable.

  Therefore, the present invention has a technical feature that the reflection point position is estimated by properly using the two-circle intersection process and the two-circle intersection process according to the part of the object detected by the distance sensor 100. And by having such a technical feature, it is possible to accurately estimate the reflection point position of the object that is the detection target of the distance sensor 100. As a result, since the estimation accuracy of the parking space information can be improved, parking assistance can be performed appropriately.

  Next, a series of operations of the parking assist device 300 when the driver performs parallel parking will be described with reference to FIGS. FIG. 7 is an explanatory diagram showing the operation of the parking support apparatus 300 when the parking support apparatus 300 estimates the parking space information of the own vehicle in the first embodiment of the present invention. FIG. 8 is an explanatory diagram showing the operation of the parking assist device 300 when the host vehicle moves from the state of FIG. 7 to the parking space in the first embodiment of the present invention. FIG. 9 is an explanatory diagram showing the operation of the parking assist device when the host vehicle further moves to the parking space from the state of FIG. In addition, although a series of operation | movement of the parking assistance apparatus 300 when a driver | operator performs parallel parking is demonstrated here, a series of operation | movement of the parking assistance apparatus 300 when a driver | operator performs parallel parking is also the same.

  First, as shown in FIG. 7, in the search mode state, the distance sensor 100 detects the second parked vehicle and then the first parked vehicle by the vehicle moving in the arrow direction. Thereby, the parking assistance apparatus 300 can determine whether parking is possible in a parking space that exists between the first parked vehicle and the second parked vehicle.

  Specifically, the parking space estimation unit 315 uses the reflection point position information input from the reflection point estimation unit 314 to estimate the position of the corner portion of the parked vehicle adjacent to the parking space as the corner estimation position. In addition, as a method for estimating the corner estimated position using the reflection point position information, a known method may be used, and for example, a method disclosed in Patent Document 1 may be used.

  Subsequently, the parking space estimation unit 315 approximates the shape of each parked vehicle by a rectangle from the respective corner estimated positions of the first parked vehicle and the second parked vehicle, thereby determining the parked vehicle estimated position. Estimate as If the size of the parked vehicle can be measured, the measured value is used. If the size of the parked vehicle cannot be measured, approximation is performed using a preset size. By such processing, the parking space estimation unit 315 can estimate object information.

  In addition, the parking space estimation unit 315 estimates the parking space position as the parking space estimated position from the estimated corner estimated position and the estimated parking vehicle estimated position, and determines the width of the parking space and the width of the parking space. presume. By such processing, the parking space estimation unit 315 can estimate the parking space information.

  The vehicle control unit 320 determines whether or not the own vehicle can be parked in the parking space, using the width of the parking space or the width of the parking space estimated by the parking space estimation unit 315. When the vehicle control unit 320 determines that the vehicle cannot be parked in the parking space, the entire operation of the parking assist device 300 ends.

  In the search mode state, since the part of the object detected by the distance sensor 100 is unknown, the reflection point estimation unit 314 performs the two-circle intersection process and the two-circle tangent process when estimating the reflection point position. I don't know which process is appropriate. Therefore, in the search mode state, it is determined in advance whether to use the two-circle intersection process or the two-circle tangent process, and the reflection point estimation unit estimates the reflection point position by the predetermined process. 314 is configured.

  When it is determined that the vehicle can be parked in the parking space, the vehicle control unit 320 switches the operation mode from the search mode to the guidance mode. In the guidance mode state, the vehicle control unit 320 performs parking support using the parking space information estimated by the parking space estimation unit 315 in the search mode state.

  In addition, while the vehicle control unit 320 is performing parking support so that the vehicle enters the parking space using the parking space information estimated in the search mode state, the parking space estimation unit 315 displays the parking space information. By correcting, the estimation accuracy of parking space information is improved. That is, it is considered that the parking space information estimated by the parking space estimation unit 315 in the search mode state has an estimation error with respect to the actual parking space.

  Therefore, also in the guidance mode state, the parking space estimation unit 315 newly estimates object information using the reflection point position information input from the reflection point estimation unit 314, and uses the newly estimated object information. Correct the parking space information. By such processing, the vehicle control unit 320 performs parking support using the corrected parking space information corrected by the parking space estimation unit 315, so that the host vehicle is parked at a more appropriate position in the parking space. be able to.

  Here, the correction of the parking space information by the parking space estimation unit 315 in the guidance mode state will be described in more detail with reference to FIGS.

  As shown in FIG. 8, in the guidance mode state, the reflection site estimation unit 313 includes the shape of the parked vehicle, the corner estimated position, and the parked vehicle estimated position included in the object information estimated in the search mode state. The part of the parked vehicle detected by the distance sensor 100 can be estimated from the known sensor information of the distance sensor 100 and the current position of the host vehicle.

  As shown in FIG. 8, when it is estimated that the side surface portion of the parked vehicle is detected by the distance sensor 100, the reflection point estimation unit 314 estimates the reflection point position by the two-circle tangent process. On the other hand, as shown in FIG. 9, when it is estimated that the corner portion of the parked vehicle is detected by the distance sensor 100, the reflection point position is estimated by the two-circle intersection process.

  As described above, in the guidance mode state, the reflection point estimation unit 314 uses the two-circle tangent process and the two-circle intersection process according to the part of the object detected by the distance sensor 100, and newly sets the reflection point position. presume. Then, the reflection point estimation unit 314 improves the estimation accuracy of the reflection point position by reflecting the newly estimated reflection point position in the guidance mode state to the reflection point position estimated in the search mode state. Can be made.

  In addition, in the guidance mode state, the parking space estimation unit 315 sequentially corrects the parking space information by using the newly estimated reflection point position each time the reflection point position is newly estimated. The vehicle control unit 320 performs parking support using the more accurate parking space information after the correction. As a result, the own vehicle can be parked at a more appropriate position in the parking space.

  In the first embodiment, the reflection point estimation unit 314 is configured to estimate the reflection point position by a predetermined process in the search mode state. However, the reflection point estimation unit 314 may be configured to perform two processes of the two-circle intersection process and the two-circle tangent process in parallel and output the two processing results to the parking space estimation unit 315.

  In this case, the parking space estimation unit 315 estimates the object information from the two processing results of the two-circle intersection process and the two-circle tangent process, and 2 as the reflection point position of the part corresponding to the side surface portion of the object from the estimated object information. The processing result by the circle tangent processing is adopted, and the processing result by the two-circle intersection processing is adopted as the reflection point position corresponding to the corner portion, and then the parking space information is estimated.

  Thus, in the search mode state, the parking space estimation unit 315 can estimate the reflection point position of the object with higher accuracy, and as a result, can estimate the parking space information with higher accuracy.

  As described above, according to the first embodiment, the reflection point estimation unit responds to the part of the object detected by the distance sensor estimated by the reflection part estimation unit while parking assistance is performed by the vehicle control unit. Thus, the reflection point position is newly estimated by properly using the two-circle tangent process and the two-circle intersection process. Specifically, the reflection point estimation unit uses a two-circle intersection process when the part of the object is estimated to be a point-shaped part, and when the part of the object is estimated to be a surface-shaped part. The reflection point position is newly estimated using the 2-circle tangent process. The parking space estimation unit corrects the parking space information by newly estimating the object information using the reflection point position newly estimated by the reflection point estimation unit.

  By executing the reflection point estimation process and the parking space estimation process with such a configuration, it is possible to accurately estimate the reflection point position of the object that is the detection target of the distance sensor without any additional hardware. As a result, the estimation accuracy of the parking space information can be improved, and appropriate parking assistance can be provided to the driver.

  DESCRIPTION OF SYMBOLS 100 Distance sensor, 200 Vehicle information sensor, 300 Parking assistance apparatus, 310 Object detection part, 311 Object classification part, 312 Own vehicle position estimation part, 313 Reflection part estimation part, 314 Reflection point estimation part, 315 Parking space estimation part, 320 Vehicle control unit.

Claims (3)

A distance sensor for detecting distance data to the object by irradiating the object to be detected with a detection wave and obtaining a detection wave reflected at a reflection point position on the object corresponding to the shortest distance to the object; And a vehicle information sensor that detects a state related to the speed and traveling direction of the host vehicle as host vehicle data, based on a time-series detection result by the distance sensor and the vehicle information sensor while moving the host vehicle. When the operation mode is the search mode, a parking space in which the host vehicle can be parked is estimated. When the operation mode is the guidance mode, guidance for parking the host vehicle in the parking space is performed. A parking assistance device that performs assistance processing,
A reflection point estimation unit that estimates the reflection point position of the object in time series from the time series detection results by the distance sensor and the vehicle information sensor;
The reflection point position estimated in time series by the reflection point estimation unit is used to estimate object information for specifying the position of the object, and a parking space in which the host vehicle can be parked using the estimated object information. A parking space estimation unit that estimates parking space information to be identified;
A vehicle control unit that performs parking support for parking the host vehicle in the parking space according to the parking space information estimated by the parking space estimation unit;
While the parking support is being performed by the vehicle control unit from the object information estimated by the parking space estimation unit and the current position of the host vehicle, the part of the object detected by the distance sensor is determined. A reflection site estimation unit that estimates in time series;
With
An arc corresponding to the detection range of the distance sensor defined by the distance data detected by the distance sensor at the current time, with the position of the distance sensor at the current time as a center, is defined as a first arc, and is more than the current time. In the case where the arc corresponding to the detection range of the distance sensor defined by the distance data detected by the distance sensor at the past time is a second arc centered on the position of the distance sensor at the previous past time The method of setting the intersection point of the first arc and the second arc as the reflection point position is defined as a two-circle intersection process, and a common tangent line of the first arc and the second arc is drawn to contact the common tangent line. When the method of setting the contact point on the first arc as the reflection point position is defined as a two-circle tangent process,
The reflection point estimation unit is
When the operation mode is the search mode, the reflection point position is estimated in time series using at least one of the two-circle intersection process and the two-circle tangent process,
When the operation mode is the guidance mode, the object detected by the distance sensor estimated in time series by the reflection part estimation unit while the parking control is performed by the vehicle control unit. Depending on the part, when the part of the object is a point-shaped part, the two-circle intersection process is used, and when the part of the object is a surface-shaped part, the reflection point position is determined using the two-circle tangent process. Estimate a new time series,
The parking space estimation unit
When the operation mode is the guidance mode, the parking space information is corrected by newly estimating the object information using the reflection point position newly estimated by the reflection point estimation unit. Support device. The reflection point estimation unit is
When the operation mode is the search mode, the two circle intersection process and the two circle tangent process are performed in parallel, and two processing results are output to the parking space estimation unit.
The parking space estimation unit
The object information is estimated from the two processing results, and the processing result by the two-circular tangent processing is adopted and estimated as the reflection point position of the portion corresponding to the surface shape portion of the object from the estimated object information. The parking support apparatus according to claim 1, wherein the parking space information is estimated after adopting a processing result by the two-circle intersection process as a reflection point position of a portion corresponding to the point shape portion of the object from the object information. . A distance sensor for detecting distance data to the object by irradiating the object to be detected with a detection wave and obtaining a detection wave reflected at a reflection point position on the object corresponding to the shortest distance to the object; And a vehicle information sensor that detects a state related to the speed and traveling direction of the host vehicle as host vehicle data, based on a time-series detection result by the distance sensor and the vehicle information sensor while moving the host vehicle. When the operation mode is the search mode, a parking space in which the host vehicle can be parked is estimated. When the operation mode is the guidance mode, guidance for parking the host vehicle in the parking space is performed. A parking assistance method executed by a parking assistance device that performs assistance processing,
A reflection point estimation step for estimating the reflection point position of the object in time series from the time series detection results by the distance sensor and the vehicle information sensor;
The reflection point position estimated in time series in the reflection point estimation step is used to estimate object information for specifying the position of the object, and a parking space in which the host vehicle can be parked using the estimated object information. A parking space estimation step for estimating the parking space information to be identified;
A vehicle control step for providing parking assistance for parking the vehicle in the parking space according to the parking space information estimated in the parking space estimation step;
From the object information estimated in the parking space estimation step and the current position of the host vehicle, the part of the object detected by the distance sensor is detected while the parking support is being performed in the vehicle control step. Reflection site estimation step for estimating in time series,
With
An arc corresponding to the detection range of the distance sensor defined by the distance data detected by the distance sensor at the current time, with the position of the distance sensor at the current time as a center, is defined as a first arc, and is more than the current time. In the case where the arc corresponding to the detection range of the distance sensor defined by the distance data detected by the distance sensor at the past time is a second arc centered on the position of the distance sensor at the previous past time The method of setting the intersection point of the first arc and the second arc as the reflection point position is defined as a two-circle intersection process, and a common tangent line of the first arc and the second arc is drawn to contact the common tangent line. When the method of setting the contact point on the first arc as the reflection point position is defined as a two-circle tangent process,
In the reflection point estimation step,
When the operation mode is the search mode, the reflection point position is estimated in time series using at least one of the two-circle intersection process and the two-circle tangent process,
When the operation mode is the guidance mode, the object detected by the distance sensor estimated in time series in the reflection site estimation step while the parking assistance is performed in the vehicle control step. Depending on the part, when the part of the object is a point-shaped part, the two-circle intersection process is used, and when the part of the object is a surface-shaped part, the reflection point position is determined using the two-circle tangent process. Estimate a new time series,
In the parking space estimation step,
When the operation mode is the guidance mode, the parking space information is corrected by newly estimating the object information using the reflection point position newly estimated in the reflection point estimation step. Support method.

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