JP4613871B2 - Parking assistance device - Google Patents

Description

  The present invention relates to a parking support apparatus that supports parking.

  2. Description of the Related Art Conventionally, an imaging unit that captures an outside of a vehicle and a display unit that displays a captured image are provided, and a target parking frame is displayed on a screen of the display unit to assist a parking operation performed by the driver of the vehicle. A parking assist device, which obtains a vehicle deflection angle calculated by a moving distance and a turning radius of the vehicle during a turning movement as a running state of the vehicle up to the parking preparation position, and based on this deflection angle, Estimating the target parking position with respect to the parking preparation position, calculating an initial setting position of the target parking frame based on the estimated target parking position, and displaying the target parking frame at the initial setting position. A characteristic parking assistance device is known (see, for example, Patent Document 1).

Further, a technique for detecting a parking space that may exist adjacent to a parked vehicle based on a distance data series (dot sequence) to the parked vehicle detected by a distance measuring means such as a laser radar is known (for example, , See Patent Document 2).
Japanese Patent No. 3729786 JP 2002-243857 A

  However, unlike the configuration described in Patent Document 2, the configuration described in Patent Document 1 is advantageous in terms of cost and the like because it does not use distance measuring means such as a laser radar, but cannot detect a parking space. Therefore, parking assistance cannot be started until the parking preparation position (parking start position) is reached. For example, appropriate guidance to the parking start position cannot be performed. Further, the reliability of the estimation accuracy of the target parking position is inevitably low.

  On the other hand, in the configuration described in Patent Document 2, the position of the parking space can be detected with relatively high accuracy by using the distance measuring unit, but a plurality of parking spaces can be detected as candidates. It is necessary to select which parking space among the spaces is the parking space intended by the driver. For example, in a parking lot where parking frame lines are arranged on both sides of a passage, it is necessary to select which side of the parking space detected on both sides of the vehicle is the parking space intended by the driver. is there. If there is an error in the selection, parking assistance for a parking space that is not intended by the user will be executed. Therefore, even if parking assistance can be started at an early stage, it will be bothersome for the user. If there is an error in the selection, the target parking frame is intended by the driver on the screen when setting the target parking position based on the screen operation (touch panel operation) performed by the driver at the parking start position. Initially displayed in a parking space different from the parking space, the user must operate the touch switch to move the position of the target parking frame to the intended parking space position. There is a problem that it takes a great burden.

  In view of the above, an object of the present invention is to provide a parking assist device capable of accurately selecting a parking space that matches a driver's intention even in a situation where parking spaces are detected on both sides of the vehicle.

In order to achieve the above object, the first invention provides a parking space detecting means for detecting parking spaces existing on the left and right sides of the vehicle, and one of the parking spaces on both sides of the vehicle detected by the parking space detecting means. A parking support device that includes a selection unit that selects a parking space on the side, and that supports parking in the garage for the parking space on one side selected by the selection unit;
It has direction information acquisition means for acquiring information about the direction of the vehicle,
The selection means is on the opposite side to the direction of change of the vehicle direction in a section at a predetermined distance from the vehicle position when the parking space is selected among the parking spaces on both sides of the vehicle detected by the parking space detection means. A parking space is selected.

2nd invention is the parking assistance apparatus which concerns on 1st invention,
The selection means selects the parking space on the left side of the vehicle when the amount of change in the direction of the vehicle in the section at a predetermined distance from the vehicle position when selecting the parking space is smaller than the predetermined amount. .

  ADVANTAGE OF THE INVENTION According to this invention, the parking assistance apparatus which can select the parking space which matched a driver | operator's intent with high precision also in the condition where a parking space is detected on both sides of a vehicle is obtained.

  The best mode for carrying out the present invention will be described below with reference to the drawings.

  FIG. 1 is a system configuration diagram showing an embodiment of a parking assistance apparatus 10 according to the present invention. As shown in FIG. 1, the parking assistance device 10 is configured around an electronic control unit 12 (hereinafter referred to as “parking assistance ECU 12”). Parking assistance ECU12 is comprised as a microcomputer which consists of CPU, ROM, RAM, etc. which were mutually connected via the bus | bath which is not shown in figure. The ROM stores programs and data executed by the CPU.

  The parking assist ECU 12 detects a steering angle sensor 16 that detects a steering angle of a steering wheel (not shown) and a vehicle speed via an appropriate bus such as a CAN (Controller Area Network) or a high-speed communication bus. A vehicle speed sensor 18 is connected. The vehicle speed sensor 18 may be a wheel speed sensor that is disposed on each wheel and generates a pulse signal at a cycle according to the wheel speed.

  The parking assist ECU 12 is connected to a distance measuring sensor 70 that detects a distance from an obstacle using sound waves (for example, ultrasonic waves), radio waves (for example, millimeter waves), light waves (for example, laser), or the like. The distance measuring sensor 70 may be any sensor that can detect a distance, such as a laser vision, a millimeter wave radar, an ultrasonic radar, or a stereo vision. The distance measuring sensor 70 is set on both the left and right sides of the front portion of the vehicle.

  As shown in FIG. 2, the distance measuring sensor 70 detects a distance from an obstacle on the side of the vehicle by emitting a sound wave or the like in a predetermined direction centered on the vehicle width direction and receiving the reflected wave. To do. The distance measuring sensor 70 is mounted, for example, near the bumper in the front part of the vehicle, and may emit a sound wave or the like toward a diagonally forward direction of 17 degrees to 20 degrees with respect to the vehicle lateral direction.

  FIG. 3 is a schematic diagram showing a point sequence related to the vehicle Z obtained when a vehicle (vehicle) including the distance measuring sensor 70 travels near the obstacle (vehicle Z) in FIG. As shown in FIG. 3, the distance measuring sensor 70 may output an obstacle reflection part (a set of reflection points such as sound waves) in a point sequence, and output data is stored in a memory 72 (for example, for each output cycle). EEPROM) may be stored at any time.

  A reverse shift switch 50 and a parking switch 52 are connected to the parking assist ECU 12. The reverse shift switch 50 outputs an ON signal when the shift lever is operated to the reverse position (reverse), and maintains the OFF state in other cases. Moreover, the parking switch 52 is provided in the vehicle interior and can be operated by the user. The parking switch 52 is normally maintained in an off state, and is turned on by a user operation.

  The parking assistance ECU 12 determines whether or not the user needs parking assistance based on the output signal of the parking switch 52. That is, when the parking switch 52 is turned on while the vehicle is traveling, the parking assist ECU 12 starts parking assist control for assisting the vehicle traveling to the target parking position in the parking space as soon as possible. The parking support control includes not only vehicle control such as steering control when traveling to the target parking position, but also information output to the driver such as output of a guidance message for guiding the vehicle to the parking start position.

  FIG. 4 is a block diagram illustrating main functions of the parking assist ECU 12 according to the present embodiment. The parking assist ECU 12 includes a parking space detection unit 41, an information output control unit 42, a deflection angle calculation unit 43, a parking start position calculation unit 44, a parking space selection unit 46, a target movement trajectory calculation unit 48, a target A parking position determination unit 49. Hereinafter, the configuration and function of each unit will be described.

  The parking space detection unit 41 detects a parking space that may exist on the side of the vehicle based on the detection result (point sequence) of the distance measuring sensor 70. Based on the detection results of the left and right distance measuring sensors 70, the parking space detection unit 41 detects parking spaces that may exist on the left and right sides of the vehicle independently on the left and right sides in parallel. Since the left and right detection methods may be the same, the detection method on one side will be described below unless otherwise specified.

  The parking space detection method differs between garage parking and parallel parking. Hereinafter, an example of a parking space detection method in the case of garage parking will be described first, and then an example of a parking space detection method in the case of parallel parking will be described. The parking switch 52 may include a switch for specifying either garage parking or parallel parking. In this case, the parking assist ECU 12 may select a parking mode (garage insertion mode or parallel mode) according to the designated parking mode. ).

[Parking space detection method for garage parking]
FIG. 5 is a plan view showing the situation of a parking lot for parking in a garage. In this situation, there are a plurality of parking spaces (indicated by dotted squares) on both sides of the vehicle, and an obstacle adjacent to the parking space. (Vehicle Z) is parked. In FIG. 5, it is assumed that the vehicle (the host vehicle) passes through the side of the obstacle (and the parking space adjacent thereto) in the direction indicated by the arrow in the figure. In the following description, the back side and the near side are based on the traveling direction of the vehicle (own vehicle).

  First, as a premise, when the vehicle passes by a side of a certain obstacle, the obstacle detection area (the length of the point sequence) by the distance measuring sensor 70 increases as the vehicle moves. The parking space detection unit 41 of this example grasps the presence of an obstacle in three stages based on the detection result by the distance measuring sensor 70.

  The first stage is a stage at which an obstacle starts to be detected. For example, the length of the point sequence is less than 1 m. The parking space detection unit 41 sets a flag (hereinafter referred to as “detection start flag”) indicating that an obstacle appears to be present on the side of the vehicle when the length of the point sequence becomes 80 cm or more, for example. Here, the reason why it seems to be an obstacle is that there is a possibility of noise when the length of the point sequence is less than 1 m.

  The two stages are intermediate stages, for example, stages in which the length of the point sequence is 1 m or more. The parking space detection unit 41 sets a flag (hereinafter, “provisional flag”) that means that an obstacle has been provisionally detected.

  The third stage is a final stage in which a point sequence having a predetermined length (> 1 m) is detected, and the point sequence no longer exists after 50 cm. In this case, since it can be determined that the entire obstacle has been detected, the parking space detection unit 41 has a flag (hereinafter referred to as “the obstacle is present on the side of the vehicle) and the detection of the obstacle has been completed. Set the completion flag.

  After the completion flag is set, the parking space detection unit 41 determines that there is a parking space on the side of the vehicle when there is no point sequence longer than a predetermined length (for example, 2 m), and a flag (hereinafter, “ Set parking space valid flag "). In this example, the parking space detection unit 41 relates to the completion flag when a point sequence having a predetermined length (> 1 m) is detected and the point sequence no longer exists after the predetermined length L1. It is determined that there is a parking space behind the obstacle, and a parking space valid flag is set. The predetermined length L1 is a minimum opening width necessary as a parking space for garage parking, and is a value that should be determined depending on the vehicle width of the own vehicle (L1 = 2.5 m in this example). ).

  When the parking space valid flag is set, the driver can be notified that the parking space exists on the side of the vehicle under the control of the information output control unit 42 as described later. This notification output mode may be realized by sound and / or video (the output mode will be described in detail later). Thereby, the driver can know that there is a parking space that can be parked on the side, and the burden of searching for the parking space with his own eyes is reduced.

  In the case of parking in the garage, for example, when parking in the parking space on the front side of the obstacle vehicle Z, if the steering wheel is not started from the vicinity of the front side of the vehicle Z, assistance to the parking space (when the vehicle moves backward) It is often difficult to reach a parking start position where assistance is possible. In the present embodiment, in consideration of this, the space on the back side, not the front side of the obstacle, is set as the detection / notification target parking space. In this case, when a predetermined space (a space having an opening width of 2.5 m) is detected on the back side of the obstacle, a notification that informs the parking space is performed. In addition, it is possible to reach the parking start position where it is possible to support the parking space without difficulty. Similarly, a parking space between two obstacles (for example, an upper left parking space between the obstacle Z2 and the obstacle Z3) is similarly a predetermined space (opening width) on the back side of the obstacle Z2 on the near side. When a space of 2.5 m is detected, a notification that informs the parking space behind the obstacle Z2 (the parking space between the obstacle Z2 and the obstacle Z3) is performed. However, as will be described later, when the parking space to be supported is selected by the parking space selection unit 46, the notification is executed only for the selected parking space to be supported.

[Parallel parking parking space detection method]
FIG. 6 is a plan view showing the situation of the parking lot. In this situation, there are a plurality of parking spaces (indicated by dotted squares) on both sides of the vehicle, and an obstacle (vehicle Z) is adjacent to the parking space. Parked. In FIG. 6, it is assumed that the vehicle (the host vehicle) passes through the side of the obstacle (and the parking space adjacent thereto) in the direction indicated by the arrow in the figure.

  In the case of parallel parking, the parking space detection unit 41 grasps the presence of an obstacle in two stages based on the detection result by the distance measuring sensor 70.

  Specifically, the parking space detection unit 41 sets the provisional flag when, for example, the length of the point sequence becomes 2.0 m or more. In addition, the parking space detection unit 41 sets a completion flag when a point sequence having a predetermined length (> 2.0 m) is detected and there is no point sequence of 50 cm or more thereafter.

  The parking space detection unit 41 determines that there is a parking space on the side of the vehicle when the point sequence appears and the provisional flag is set from the state where the point sequence does not exist for the predetermined length L2 or more, and the parking space Set the enable flag. That is, the parking space detection unit 41 parks the front side of the obstacle related to the temporary flag when there is no point sequence of the predetermined length L2 and after that, for example, a point sequence of 2.0 m or more is detected. It is determined that there is a space, and a parking space valid flag is set. The predetermined length L2 is a minimum opening width necessary as a parking space for parallel parking, and is a value that should be determined depending on the total length of the own vehicle (L2 = 6 m in this example).

  In addition, after the completion flag is set, the parking space detection unit 41 determines that there is a parking space on the side of the vehicle when there is no point sequence more than a predetermined length (for example, L2-0.5 [m]), Set the parking space valid flag. In this example, the parking space detection unit 41 detects the completion flag when a point sequence having a predetermined length (> 2.0 m) is detected and no point sequence exists after the predetermined length L2. It is determined that there is a parking space on the back side of the obstacle according to, and a parking space valid flag is set.

  When the parking space validity flag is set, similarly, the driver can be notified that the parking space exists on the side of the vehicle under the control of the information output control unit 42 as described later. Thereby, the driver can know that there is a parking space that can be parked on the side, and the burden of searching for the parking space with his own eyes is reduced.

  In the case of parallel parking, the detection area of the obstacle to be detected (in the case of a vehicle, the side surface of the vehicle) is larger than in the case of parking in the garage, and it is not necessary to start turning the steering wheel at an early stage. In this embodiment, in consideration of this, the point sequence length when setting the provisional flag is increased compared to the case of parking in the garage, and the space on both the front side and the back side of the obstacle is increased. The parking space is subject to detection and notification. In this case, when a predetermined space (space with an opening width of 6 m) is detected on the front side of the obstacle, or when a predetermined space (space with an opening width of 6 m) is detected on the back side of the obstacle, Since the notification that informs the parking space is performed, it is possible to reach the parking start position where the parking space can be supported without difficulty from the point where the notification is made. However, as will be described later, when the parking space to be supported is selected by the parking space selection unit 46, the notification is executed only for the selected parking space to be supported.

  Next, processing realized by the deflection angle calculation unit 43 will be described. Output signals of the steering angle sensor 16 and the vehicle speed sensor 18 (see FIG. 1) are input to the deflection angle calculation unit 43 at predetermined intervals. The deflection angle calculation unit 43 calculates the amount of change in the direction of the vehicle in a predetermined section (hereinafter referred to as “deflection angle α”) based on the output signals of the steering angle sensor 16 and the vehicle speed sensor 18. The predetermined section is, for example, a section that is a predetermined distance (for example, 7 m) from the current vehicle position. The deflection angle α is defined as positive in the clockwise direction and negative in the counterclockwise direction. Here, in general, the deflection angle α can be calculated by the equation (1), where ds is a minute movement distance of the vehicle and γ is a road curvature (corresponding to the reciprocal of the turning radius R of the vehicle). This formula 1 is to obtain the deflection angle α as a change in the direction of the vehicle from the position before βm (β = 7 in this example) to the local point.

本実施例の駐車支援ＥＣＵ１２は、数１の式を変形した以下の数２の式に基づいて、所定の移動距離（本例では、０．５ｍ）毎の微小偏向角α_ｉを算出すると共に、算出した各微小偏向角α_１〜ｋを総和して偏向角αを算出する。

The parking assist ECU 12 according to the present embodiment calculates a minute deflection angle α _i for each predetermined movement distance (0.5 m in this example) based on the following formula 2 obtained by modifying the formula 1 Then, the calculated small deflection angles α ₁ to _k are summed to calculate the deflection angle α.

この際、所定の移動距離（本例では、０．５ｍ）は、車速センサ１８の出力信号（車輪速パルス）を時間積分することによって監視される。また、路面曲率γは、舵角センサ１６から得られる舵角Ｈａに基づいて決定され、例えばγ＝Ｈａ／Ｌ・ηにより演算される（Ｌはホイールベース長、ηは車両のオーバーオールギア比（車輪の転舵角に対する舵角Ｈａの比）である）。尚、微小偏向角α_ｉは、微小移動距離０．０１ｍ毎に得られる路面曲率γに当該微小移動距離０．０１を乗算し、これらの乗算値を移動距離０．５ｍ分積算することによって算出されてもよい。尚、路面曲率γと舵角Ｈａとの関係は、予め車両毎に取得された相関データに基づいて作成されたマップとして、駐車支援ＥＣＵ１２のＲＯＭに格納されていてよい。

At this time, the predetermined moving distance (0.5 m in this example) is monitored by time-integrating the output signal (wheel speed pulse) of the vehicle speed sensor 18. The road surface curvature γ is determined based on the steering angle Ha obtained from the steering angle sensor 16, and is calculated by, for example, γ = Ha / L · η (L is the wheelbase length, η is the overall gear ratio of the vehicle ( The ratio of the steering angle Ha to the steering angle of the wheel)). Note that the minute deflection angle α _i is calculated by multiplying the road surface curvature γ obtained every minute movement distance 0.01 m by the minute movement distance 0.01 and integrating these multiplied values by the movement distance 0.5 m. May be. The relationship between the road surface curvature γ and the steering angle Ha may be stored in the ROM of the parking assist ECU 12 as a map created based on correlation data acquired for each vehicle in advance.

The deflection angle α calculated in this way is used as a judgment material when the parking space selection unit 46 accurately selects the parking space intended by the driver as will be described later. The detection results of the vehicle speed sensor 18 and the rudder angle sensor 16 (or the data of the minute deflection angle α _i based on the detection results) are the same as the detection results of the distance measuring sensor 70 even in a situation where the parking switch 52 is not turned on. It is desirable to be memorized. As a result, when the parking switch 52 is turned on, the deflection angle α in the section 7 m ahead from the vehicle position at that time can be calculated. Is possible.

  Next, a parking space selection process realized by the parking space selection unit 46 will be described.

  FIG. 7 is a flowchart showing a parking space selection process realized by the parking space selection unit 46 in a garage parking scene. Note that the processing routine shown in FIG. 7 (and FIG. 8 below) is executed when the current parking mode is the garage entry mode. The current parking mode (garage insertion mode or tandem mode) may be specified when the parking switch 52 is operated. For example, the surrounding state detection means (for example, image recognition by a camera) or map data (for example, parking lot position information) In addition, it may be estimated and determined based on the map data storing the parking lot form.

  The processing routine shown in FIG. 7 is executed, for example, in a parking lot where the parking frame lines on both sides of the passage are lined up (see FIG. 9) while the vehicle driver is driving the vehicle while searching for a desired parking space. The selected parking space is particularly preferably used for parking assistance for guiding the vehicle to the parking start position.

  In step 100, the parking space selection unit 46 determines whether or not the parking space detection flag is set by the parking space detection unit 41. If the parking space valid flag is set, the process proceeds to step 110. Otherwise, the current processing routine is terminated.

  In step 110, the parking space selection unit 46 determines whether the parking space valid flag is set for the parking space on the left side of the vehicle or the parking space on the right side. This determination can be easily realized because the left and right distance measuring sensors 70 independently detect the parking space as described above. If the parking space valid flag is set for the parking space on the left side of the vehicle, the process proceeds to step 120. If the parking space valid flag is set for the parking space on the right side, the process proceeds to step 140.

  In step 120, the parking space selection unit 46 determines the direction of change of the vehicle direction based on the deflection angle calculated by the deflection angle calculation unit 43, and determines whether or not the direction of change of the vehicle direction is the right side. judge. Specifically, the parking space selection unit 46 determines whether or not the deflection angle α in a section of a predetermined distance in front (for example, 7 m) from the current vehicle position is within a range of 0 <α <θ1. θ1 is a relatively small angle, and may be, for example, 5 degrees. In this case, when the deflection angle α is within the range of 0 <α <θ1, the parking space selection unit 46 determines that the direction of change of the vehicle direction is the right side, and determines that the left side parking space is It is selected as a parking space to be supported (step 130). On the other hand, when the deflection angle α is outside the range of 0 <α <θ1, the process for the currently set parking space valid flag is performed without selecting the currently detected parking space as the parking space to be supported. Is terminated.

  Here, the fact that the deflection angle α is within the range of 0 <α <θ1 means a state in which the vehicle that has been traveling straight is starting to turn rightward. Generally, when attempting to park in the parking space on the left side of the vehicle, the driver tends to start turning the steering wheel in the right direction when passing through the parking space. Therefore, according to the present embodiment, by detecting this tendency based on the deflection angle α, the parking space on the side intended by the driver can be accurately selected even in a situation where parking spaces can exist on both sides of the vehicle. can do.

  In step 140, the parking space selection unit 46 determines the direction of change of the vehicle direction based on the deflection angle calculated by the deflection angle calculation unit 43, and determines whether or not the direction of change of the vehicle direction is the left side. judge. Specifically, the parking space selection unit 46 determines whether or not the deflection angle α in a section a predetermined distance (for example, 7 m) from the current vehicle position is within a range of −θ1 <α <0. θ1 is a relatively small angle, and may be, for example, 5 degrees. In this case, when the deflection angle α is in the range of −θ1 <α <0, the parking space selection unit 46 determines that the direction of change of the vehicle direction is the left side, and determines that the right parking space is Then, it is selected as a parking space to be supported (step 150). On the other hand, when the deflection angle α is outside the range of −θ1 <α <0, the processing for the parking space validity flag set this time is performed without selecting the parking space detected this time as the parking space to be supported. Is terminated.

  Here, the fact that the deflection angle α is in the range of −θ1 <α <0 means a state in which the vehicle that has been traveling straight is starting to turn leftward. Generally, when attempting to park in the parking space on the right side of the vehicle, the driver tends to start turning the steering wheel in the left direction when passing through the parking space. Therefore, according to the present embodiment, by detecting this tendency based on the deflection angle α, the parking space on the side intended by the driver can be accurately selected even in a situation where parking spaces can exist on both sides of the vehicle. can do.

  When the parking space to be supported is selected in this way, the parking space selection unit 46 notifies the information output control unit 42, the parking start position calculation unit 44, and the like of the selected parking space.

  When the parking start position calculation unit 44 receives the notification, the parking start position calculation unit 44 calculates a parking start position that can support the selected parking space (a parking start position that can generate a trajectory to the target parking position in the parking space). There are various ways to calculate the parking start position. For example, the parking start position calculation unit 44 determines the target parking direction in the parking space (how the vehicle is parked in the parking space) based on the deflection angle α of the vehicle (own vehicle) when passing through the parking space. And the target parking position (for example, the rear axle of the vehicle in the parking space) based on the end point P (see FIG. 3) of the obstacle adjacent to the parking space (the obstacle related to the set completion flag or provisional flag). The center position) may be determined. Alternatively, if possible, the direction of the obstacle is estimated by performing a straight line or curved line approximation on the point sequence representing the obstacle for which the completion flag is set, and the target parking is performed based on the direction of the obstacle. The direction may be determined. After determining the target parking direction and the target parking position, the parking start position calculation unit 44 then considers the maximum turning curvature of the vehicle and the like, and the parking start position where parking in the determined target parking direction and target parking position is possible. (Including the direction of the vehicle at the start of parking). In addition, since the parking start position which can assist the parking space has a range instead of a single point, the parking start position determined by the parking start position calculation unit 44 is defined by an allowable position range. It may be a thing.

  Moreover, the information output control part 42 may perform the guidance output of a parking space based on the selected parking space, if this notification is received. For example, the information output control unit 42 outputs a sound “pawn” via the speaker 24 (see FIG. 1) and issues a steering instruction for guiding the vehicle to the parking start position. Note that the sound of pawn may be output from the speaker 24 on the side where the parking space exists, among the speakers 24 present on the left and right. Thereby, the driver can understand the side where the parking space exists through hearing. In addition, the steering instruction may be a voice output indicating, for example, “Please move slowly until you hear a ping pong while turning the steering wheel”.

  As described above, according to the present embodiment, only the parking space selected by the parking space selection unit 46 is notified of the presence of the parking space, so that the driver can accurately determine the parking space intended for parking. In addition to being able to notify, it is possible to prevent the driver from unnecessarily reporting a parking space that is not intended for parking.

  In this embodiment, the voice guidance for informing the existence of the parking space and the steering guidance for guiding the vehicle to the parking start position are realized by voice, but instead of or in addition to this, video May be realized.

  Further, in this embodiment, it is determined whether or not to notify the presence of the parking space based on two conditions including a condition related to the parking space valid flag and a condition related to the deflection angle α. This condition may be added to limit the condition for performing such notification. For example, a condition that the vehicle speed is a small value within a predetermined range may be added.

  FIG. 8 is a flowchart showing another parking space selection process realized by the parking space selection unit 46 in the garage parking scene. The processing routine shown in FIG. 8 is typically executed when the vehicle reaches the parking start position, and the selected parking space obtained by the processing routine shown in FIG. 8 assists in setting the target parking position. It is suitable to be used for parking assistance.

  In step 200, the parking space selection unit 46 determines whether or not the parking space validity flag set for the left and right parking spaces is valid at the current vehicle position. Such a situation can occur, for example, in a parking lot situation as shown in FIG. Note that the parking space valid flag is valid at the current vehicle position means that a target movement trajectory from the current vehicle position (typically, the parking start position, hereinafter the same in the description of FIG. 8) to the parking space is generated. Means that it is possible. If the determination is affirmative, the routine proceeds to step 210.

  In step 210, the parking space selector 46 determines whether or not the absolute value of the deflection angle α at the current vehicle position is smaller than a predetermined value θ2. Specifically, the parking space selection unit 46 determines whether or not the absolute value of the deflection angle α in a section at a predetermined distance (for example, 7 m) from the current vehicle position is smaller than a predetermined value θ2. Note that this process may be executed afterwards (tracing back in the past) based on past data when the vehicle reaches the parking start position. For example, the predetermined value θ2 may be substantially zero (a value that can be regarded as a straight traveling state). If the absolute value of the deflection angle α is smaller than the predetermined value θ2, the process proceeds to step 220. Otherwise, the process proceeds to step 230.

  In step 220, the parking space selection unit 46 gives priority to the left side and selects the left parking space among the parking spaces on both sides as the parking space to be supported.

  In step 230, the parking space selection unit 46 determines whether or not the direction of change of the vehicle direction to the current vehicle position is the right side based on the deflection angle α calculated by the deflection angle calculation unit 43. To do. Specifically, the parking space selection unit 46 determines whether or not the value of the deflection angle α in a section a predetermined distance (for example, 7 m) from the current vehicle position is a positive value. When the deflection angle α is a positive value, the parking space selection unit 46 determines that the change direction of the vehicle direction is the right side, and determines the left parking space among the parking spaces on both sides as the parking space to be supported. (Step 220). On the other hand, when the deflection angle α is a negative value, the parking space selection unit 46 determines that the change direction of the vehicle direction is the left side, and determines the right parking space among the parking spaces on both sides as the support target. A parking space is selected (step 240).

  FIG. 9 is a plan view schematically showing the above selection process by the parking space selection unit 46 at the time of parking in the garage. FIG. 9 shows a parking lot situation where the left and right parking spaces S1, S2 are detected substantially simultaneously.

  According to the present embodiment, as described above, as shown in FIG. 9A, when the vehicle is directed to the right side (that is, in the case of a right turn), the left parking space S1 is Selected. Further, as shown in FIG. 9B, when the vehicle is directed to the left (that is, in the case of a left turn), the right parking space S2 is selected. Further, as shown in FIG. 9C, when the direction of the vehicle is substantially zero (that is, in a straight traveling state), the left parking space S1 is selected. Thereby, even when there are a plurality of supportable parking spaces on both the left and right sides of the vehicle, the parking space intended by the user is accurately selected based on the turning mode of the vehicle at the time of parking in the garage as described above. be able to.

  FIG. 10 is a flowchart showing a parking space selection process realized by the parking space selection unit 46 in a parallel parking scene. Note that the processing routine shown in FIG. 10 is executed when the current parking mode is the column mode. As described above, the current parking mode may be specified when the parking switch 52 is operated, or may be estimated / determined based on, for example, surrounding state detection means or map data.

  The selected parking space obtained by the processing routine shown in FIG. 10 is preferably used for parking assistance that supports the setting of the target parking position, but is used for parking assistance that guides the vehicle to the parking start position. May be. Therefore, this processing routine may be executed afterwards (retroactively) based on past data when the vehicle reaches the parking start position, or as shown in the flowchart shown in FIG. The vehicle may be executed in real time in the process of reaching the parking start position.

  In step 300, the parking space selection unit 46 determines whether the parking space validity flag set for the left and right parking spaces is valid at the current vehicle position. Such a situation can occur, for example, in a parking lot situation as shown in FIG. Note that the parking space valid flag is valid at the current vehicle position means that a target movement trajectory from the current vehicle position (typically, the parking start position, hereinafter the same in the description of FIG. 10) to the parking space is generated. Means that it is possible. If the determination is affirmative, the process proceeds to step 310.

In step 310, the parking space selection unit 46, based on the output result (stored data) of the distance measuring sensor 70, the side distances D _L and D _R [m ] (See FIG. 6) and the difference in the lateral distance (= | D _L −D _R |) is obtained. For example, the lateral distance D _L to the left side of the parking space, side based on the output result of the left distance measuring sensor 70 used for detection of the parking space, to the left of the obstacle defining the parking space The distances L1 and L1 ′ (see FIG. 11) may be calculated. Similarly, the lateral distance D _R to the right of the parking space, based on the output result of the right distance measuring sensors 70 used for detecting the parking space, until the right obstacle defining the parking space It may be calculated as the lateral distances R1 and R1 ′ (see FIG. 11).

In step 320, the parking space selection unit 46 determines whether or not the difference in the lateral distance to the left and right parking spaces is smaller than a predetermined value D0. Predetermined value D0 may be a value that causes considered when the vehicle is positioned substantially equal distances with respect to the right and left parking space (e.g. 50 cm), the sum of the left and right lateral distance (= D L ₊ D _R ) may be a variable value set based on. If the difference between the lateral distances to the left and right parking spaces is smaller than the predetermined value D0, the process proceeds to step 320, and otherwise, the process proceeds to step 340.

  In step 330, the parking space selection unit 46 gives priority to the left side and selects the left parking space of the parking spaces on both sides as the parking space to be supported.

In step 340, the parking space selection unit 46 determines the lateral distance D _L to the left side of the parking space, whether less than the lateral distance D _R to the right of the parking space. If the lateral distance D _L is smaller than the lateral distance D _R, that is, when towards the left of the parking space is close to the vehicle than the right parking space, the parking space selection unit 46 among the both sides of the parking space The left parking space is selected as a parking space to be supported (step 330). When parking in a parking lot with a relatively wide aisle in parallel parking in the parking space on the left side of the vehicle, the driver brings the vehicle to the parking space side on the left side and It is based on the tendency to pass the vehicle almost straight.

On the other hand, when the lateral distance D _L is (NO judgment in step 340) is greater than the lateral distance D _R, i.e. towards the right parking space is close to the vehicle than the left parking space, the parking space The selection unit 46 selects the right parking space among the parking spaces on both sides as the parking space to be supported (step 350). This is because when a driver wants to perform parallel parking in the parking space on the right side of the vehicle in a parking lot with a relatively wide passage, the driver brings the vehicle to the parking space side on the right side and It is based on the tendency to pass the vehicle almost straight.

  FIG. 11 is a plan view schematically showing the selection process described above by the parking space selection unit 46 during parallel parking. FIG. 11 shows a parking lot situation in which the left and right parking spaces S1, S2 are detected substantially simultaneously.

  According to the present embodiment, as described above, as shown in FIG. 11A, when the vehicle is close to the left parking space S1 (that is, to the left), the left parking space S1 is selected. The Also, as shown in FIG. 10B, when the vehicle is close to the right parking space S2 (that is, when it is to the right), the right parking space S2 is selected. Further, as shown in FIG. 9C, when the vehicle is located at substantially the same distance with respect to the left and right parking spaces S1, S2, the left parking space S1 is selected. Thus, even when there are a plurality of supportable parking spaces on both the left and right sides of the vehicle, the parking space intended by the user is accurately determined based on the positional relationship of the vehicle with respect to the parking spaces on the left and right sides of the vehicle as described above. You can choose well.

  When the parking space to be supported is selected by the processing of FIGS. 8 and 10, the parking space selection unit 46 notifies the target parking position determination unit 49 of the selected parking space.

  The target parking position determination unit 49 determines the target parking position based on, for example, the output result of the distance measuring sensor 70 related to the selected parking space (stored data related to the obstacle that defines the selected parking space). In this case, the target parking position determination unit 49 may determine, for example, a point having a predetermined relative positional relationship as the target parking position with respect to the end position (end point) of the obstacle on the turning center side. The target parking position may be a concept including a target parking direction in the parking space (in which direction the vehicle is parked in the parking space). The target parking direction may be determined based on the orientation of the vehicle when passing through the selected parking space, the shape of the obstacle (approximation result) adjacent to the selected parking space, and the like. In addition, when a parking space is detected between two obstacles (for example, when there is a section without a point sequence of a predetermined length or more between the end points of the point sequence representing the two obstacles. The target parking position may be determined at an intermediate point between the respective end points of the two obstacles. At this time, the target parking direction may be similarly determined based on the direction of the vehicle, the shape of the obstacle (approximation result), a straight line connecting the end points of the two obstacles, and the like. When the target parking position determination unit 49 determines the target parking position corresponding to the parking space selected by the parking space selection unit 46, the target parking position determination unit 49 supplies information regarding the determined target parking position to the information output control unit 42.

  The information output control unit 42, based on the information about the target parking position from the target parking position determination unit 49, has a target parking frame at a position (position on the screen) corresponding to the parking space selected by the parking space selection unit 46. The initial display of is performed. Specifically, when the reverse shift switch 50 is turned on at the parking start position, the information output control unit 42 shoots a landscape in a predetermined angle area behind the vehicle on the display 22 provided in the vehicle interior. A captured image (actual image) of the camera 20 is displayed. At this time, as shown in FIG. 12 (garage parking screen), the target parking frame is superimposed on the captured image on the display 22. The target parking frame may be a figure imitating the actual parking frame or the outer shape of the vehicle. For example, the target parking frame has a form in which the position and orientation can be visually recognized by the user, and is displayed for parking in a garage (parallel parking). And two types of display for parallel parking may be prepared.

  The initial display position / direction of the target parking frame displayed on the display 22 corresponds to the target parking position / target parking direction determined as described above. The target parking frame position / orientation (= target parking position / target parking direction) may be determined as it is, for example, by a final determination switch operation by the user. Alternatively, as shown in FIG. 12, the position of the target parking frame can be adjusted before the operation of the confirmation switch by a touch switch for moving the target parking frame in the vertical and horizontal directions and rotating. Also good.

  According to the present embodiment, as described above, even if the parking spaces on both sides of the vehicle are detected as candidates, the parking space on the side that is likely to match the driver's intention is selected, and the selection is made. Since the initial display position of the target parking frame is determined based on the parking space, the target parking frame can be initially displayed at an appropriate position where the driver intends to park (opposite that the driver does not intend to park) It is possible to prevent the target parking frame from being displayed corresponding to the parking space on the side). This eliminates the need to adjust the target parking frame by operating the touch switch many times, as in the case where the target parking frame is displayed at a position in the parking space different from the driver's intention. The time required for setting can be greatly reduced.

  When the position or the like of the target parking frame is determined by the operation by the user, the target movement trajectory calculation unit 48 calculates the target movement trajectory. When the rearward movement of the vehicle is started, the information output control unit 42 uses the vehicle movement amount calculated from the output signal of the vehicle speed sensor 18 and the steering angle position obtained from the steering angle sensor 16 during the automatic guidance control. The target steering angle is calculated according to the deviation of the estimated vehicle position from the target movement trajectory, and the target steering angle is transmitted to the steering control ECU 30. The steering control ECU 30 controls the motor 32 so as to realize the target steering angle. The motor 32 may be provided in a steering column or a steering gear box and rotate the steering shaft according to the rotation angle.

  The target movement trajectory calculation unit 48 estimates and calculates the vehicle position during execution of parking assistance based on the output signals of the steering angle sensor 16 and the vehicle speed sensor 18, and calculates the target movement trajectory calculated last time and the estimated vehicle position. Depending on the difference, the current target movement trajectory may be calculated, and the target steering angle at the estimated vehicle position described above may be determined based on the target movement trajectory. The calculation of the target movement trajectory may be performed every time the vehicle moves by a predetermined movement distance (for example, 0.5 m). At this time, the target movement trajectory calculation unit 48 appropriately corrects the target parking position / target parking direction (according to the calculation of the target movement trajectory) based on the parking frame line recognition processing result for the captured image of the back monitor camera 20. May be.

  The information output control unit 42 requests the driver to stop the vehicle when the vehicle is finally placed in the target parking position in the parking space in the target parking direction (or the vehicle is automatically driven by the automatic braking means). Stop) and parking support control is completed.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  For example, in the process shown in FIG. 8 described above, the change direction of the vehicle direction taken into account when selecting the parking space is the change direction of the vehicle direction at the current vehicle position (typically, the parking start position). However, the present invention is not limited to this. For example, the change direction of the direction of the vehicle considered when selecting the parking space may be a change direction based on the deflection angle α at an arbitrary time from the setting of the parking effective flag to the parking start position.

For the same reason, the lateral distance D _L from the vehicle to be considered when selecting a parking space to the parking _space, D _R, as long as it is detected and calculated by the vehicle position during traveling near the parking space The lateral distance detected at any vehicle position may be used.

  Further, in the above-described embodiment, as shown in FIGS. 9 and 11, the left and right parking spaces S1 and S2 are detected substantially at the same time and compete with each other. However, the present invention is limited to this. Never. For example, in the present invention, the left and right parking spaces S1, S2 in the garage parking situation shown in FIG. 13A, and the left and right parking spaces S1, S2 in the parallel parking situation shown in FIG. The parking spaces S1 and S2 on both the left and right sides are detected with a slight time difference, and the present invention is also applicable to a case where they compete. However, in this case, for example, one of the parking spaces may be selected in consideration of other conditions such as the distance in the vehicle longitudinal direction and the state of the generated target track.

  Further, the processing shown in FIGS. 8 and 10 relates to a case where two parking spaces on both sides of the vehicle compete with each other, but can be similarly applied to a case where three or more parking spaces on both sides of the vehicle compete. is there. Also in this case, for example, one of the parking spaces may be selected in consideration of other conditions such as the distance in the vehicle front-rear direction and the state of the generated target track.

In the above-described embodiment, the parameter considered when selecting the competing parking space is the change direction of the vehicle direction or the lateral distance from the vehicle to the parking space, but other conditions may be added. Good. For example, the driver's line of sight that can be recognized by an indoor camera or the like may be considered.
In the above-described embodiment, the target parking frame is measured at a position (position on the screen) corresponding to the parking space selected by the parking space selection unit 46 on the target parking position setting screen shown in FIG. Although the initial display is based on the detection data of the distance sensor 70, the present invention is not limited to this. For example, the parking frame line (white line) is image-recognized based on the image captured by the back monitor camera 20, and the parking space selected by the parking space selection unit 46 is determined based on the image recognition result (the position of the parking frame line). The target parking frame may be initially displayed at a corresponding position (position on the screen).

  Further, in the above-described embodiment, on the assumption that there is a parking space that can be supported at the parking start position, the target parking frame is initially displayed in correspondence with the position of the parking space. For example, when sufficient data cannot be acquired due to the fact that no supportable parking space has been detected at the parking start position, the target parking position is determined based on the traveling pattern of the vehicle up to the parking start position, for example. The target parking frame may be initially displayed in association with the estimated target parking position.

  In the above-described embodiment, various applications are activated when the parking switch 52 is turned on. However, the present invention is not limited to this, for example, when the parking switch 52 is not turned on. However, it may be activated when the vehicle speed is equal to or lower than a predetermined value, when it is determined from the map data of the navigation device that the vehicle position is in the parking lot. In this case, a configuration in which the parking switch 52 does not exist is also conceivable.

  In the above-described embodiment, the distance measuring sensor 70 suitable as the obstacle detection unit is used. However, it is also possible to detect an obstacle (and thus a parking space) by image recognition of the camera.

  Further, the memory 72 may be a dedicated memory for storing detection data of the distance measuring sensor 70 or a memory in the parking assist ECU 12. In the former case, other data may be stored in a memory in the parking assist ECU 12.

  In the above-described embodiment, for the sake of explanation, the obstacle is assumed to be a vehicle. However, as the obstacle, any tangible object such as a bicycle, a two-wheeled vehicle, a wall, and two or more pylons can be assumed.

  In the above-described embodiment, the vehicle speed sensor 18, the steering angle sensor 16, and the deflection angle calculation unit 43 obtain and derive information related to the vehicle direction, but instead of or in addition, a yaw rate sensor, a gyro sensor, An azimuth meter, a GPS positioning result, or the like may be used.

1 is a system configuration diagram showing an embodiment of a parking assistance device 10 according to the present invention. It is explanatory drawing which shows the detection aspect of the object (the vehicle Z in this example) of the detection target of the ranging sensor. FIG. 3 is a schematic diagram showing a point sequence related to a vehicle Z obtained when a vehicle (own vehicle) including a distance measuring sensor 70 travels near the vehicle Z in FIG. 2. It is a block diagram which shows the main functions of parking assistance ECU12 of a present Example. It is a top view which shows the condition of the parking lot for garage parking. It is a top view which shows the condition of the parking lot for parallel parking. It is a flowchart which shows the parking space selection process implement | achieved by the parking space selection part 46 in the scene of garage parking. It is a flowchart which shows the other parking space selection process implement | achieved by the parking space selection part 46 in the scene of garage parking. It is a top view which shows typically the above-mentioned selection process by the parking space selection part 46 in garage parking mode. It is a flowchart which shows the parking space selection process implement | achieved by the parking space selection part 46 in the scene of parallel parking. It is a top view which shows typically the above-mentioned selection process by the parking space selection part 46 in parallel parking mode. It is a figure which shows an example of the target parking position setting touch panel on the display. It is a figure which shows the other parking lot condition which can apply this invention.

Explanation of symbols

10 Parking assistance device 12 Parking assistance ECU
16 Steering angle sensor 18 Vehicle speed sensor 20 Back monitor camera 22 Display 30 Steering control ECU
DESCRIPTION OF SYMBOLS 41 Parking space detection part 42 Information output control part 43 Deflection angle calculation part 44 Parking start position calculation part 46 Parking space selection part 48 Target movement track | orbit calculation part 49 Target parking position determination part 50 Reverse shift switch 52 Parking switch 70 Distance sensor

Claims (2)

A parking space detecting means for detecting parking spaces existing on both right and left sides of the vehicle; and a selecting means for selecting a parking space on one side of the parking spaces on both sides of the vehicle detected by the parking space detecting means, In the parking assistance device that performs garage parking assistance for the parking space on one side selected by the selection means,
It has direction information acquisition means for acquiring information about the direction of the vehicle,
The selection means is on the opposite side to the direction of change of the vehicle direction in a section at a predetermined distance from the vehicle position when the parking space is selected among the parking spaces on both sides of the vehicle detected by the parking space detection means. A parking assistance device, wherein a parking space is selected. Said selecting means, when the amount of change in orientation of the vehicle in front predetermined distance interval from the vehicle position at the time of selecting a parking space is less than the predetermined amount, selects the left side of the parking space of the vehicle, to claim 1 The parking assistance device described.

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