Route generation device, parking assistance system, and route generation method

Abstract

To provide a route generation device which generates a route for accurately parking at a parking target position.SOLUTION: A route generation device 100 includes: an own vehicle position acquiring part 10 which acquires an own vehicle position; a peripheral environmental information acquiring part 11 which acquires peripheral environmental information; a vehicle information acquiring part 12 which acquires vehicle information; a parking space information calculation part 13 which calculates a parking target position 45 and a travelable area 41 as parking space information; and a route generation part 14 which generates a route based on the own vehicle position, peripheral environmental information, vehicle information and parking space information. Therein, the route generation part 14 includes: a reference route generation part 21 which generates a reference route 51 extending to a parking target position 45 from a parking starting position 44; and a local route generation part 22 which generates, at a present position of the own vehicle being moving along the reference route 51, a local route 52 getting to a movement track which converges to a reference route 51 from the present position.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present application relates to a route generation device, a parking assistance system, and a route generation method. [Background technology]

[0002] With the development of autonomous driving technology for vehicles, various parking assistance devices that assist vehicles in parking into parking spaces have been proposed or put into practical use. For example, the parking assistance device described in Patent Document 1 calculates the amount of deviation between the current position of the vehicle and its position on a target route, corrects at least one of the target vehicle speed and the target steering angle so as to reduce the amount of deviation, and drives the vehicle along the target route with high accuracy. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2018-34540 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, in the parking assistance device described in Patent Document 1, the vehicle speed control only corrects the deviation amount due to the free running distance when the vehicle is stopped, and this deviation amount alone does not take into account the deviation amount in the lateral direction relative to the route due to steering delay and the deviation amount of the vehicle attitude angle, so it is not possible to accurately estimate the traveling distance to the parking target position. As a result, there is a possibility that the vehicle will suddenly decelerate just before the stopping position or the route length will increase.

[0005] In addition, if the parking target position, parking space information, etc. are recalculated along the route from the parking start position to the parking target position within the parking space, there is a problem in that it is not possible to calculate the correction amount required for accurate parking.

[0006] The present disclosure has been made to solve the above-mentioned problems, and aims to provide a route generation device and a route generation method that generate a route for parking a vehicle accurately at a target parking position within a parking space, as well as a parking assistance system that automatically drives along the generated route. [Means for solving the problem]

[0007] The route generation device according to the present disclosure comprises: a vehicle position acquisition unit that acquires the vehicle position; a surrounding environment information acquisition unit that acquires surrounding environment information of the host vehicle; a vehicle information acquisition unit that acquires vehicle information of the host vehicle; a parking space information calculation unit that detects a parking space and calculates a parking target position and a drivable area of ​​the vehicle as parking space information; a route generation unit that generates a route for the host vehicle to travel based on the host vehicle position, the surrounding environment information, the vehicle information, and the parking space information; The path generation unit a reference path generating unit that generates a reference path from a parking start position to the parking target position; a local route generation unit that generates, at a current position of the host vehicle while the host vehicle is moving along the reference route, a local route that is a movement trajectory that converges from the current position to the reference route. 、 The local route generation unit includes a stop position setting unit that sets a next stop position of the host vehicle based on the local route generated at a current stop position of the host vehicle when the host vehicle stops multiple times along the reference route. .

[0008] The parking assistance system according to the present disclosure comprises: The above-mentioned route generation device; and a vehicle control device that parks the vehicle in the parking space based on the route information generated by the route generation unit.

[0009] The route generation method according to the present disclosure includes: A route generation method for generating a route for a vehicle to travel from a parking start position to a parking target position, comprising: generating a reference path from the parking start position to the parking target position; generating, at a current position of the host vehicle while the host vehicle is moving along the reference route, a local route that is a movement trajectory that converges from the current position to the reference route; and when the host vehicle stops multiple times along the reference route, setting the next stopping position of the host vehicle based on a local route generated at the current stopping position of the host vehicle. [Effects of the Invention]

[0010] According to the route generation device, parking assistance system, and route generation method of the present disclosure, by generating a reference route and a local route, it is possible to generate a route that takes into account deviation from the current vehicle position to the target position even if the vehicle position deviates from the target, and it also has the effect of enabling parking in a parking space by automatic driving control along the generated route. [Brief explanation of the drawings]

[0011] [Figure 1] 1 is a block diagram of a path generating device according to a first embodiment. [Figure 2] FIG. 1 is a schematic diagram illustrating a path generating device according to a first embodiment. [Figure 3] FIG. 1 is a schematic diagram illustrating a path generating device according to a first embodiment. [Figure 4] FIG. 2 is a schematic diagram illustrating a first application example of the path generation device according to the first embodiment. [Figure 5] FIG. 2 is a schematic diagram illustrating a first application example of the path generation device according to the first embodiment. [Figure 6] FIG. 10 is a flowchart illustrating a processing flow in a first application example of the path generation device according to the first embodiment. [Figure 7] FIG. 10 is a flowchart illustrating a processing flow in a first application example of the path generation device according to the first embodiment. [Figure 8]FIG. 2 is a schematic diagram illustrating a first application example of the path generation device according to the first embodiment. [Figure 9] FIG. 2 is a schematic diagram illustrating a first application example of the path generation device according to the first embodiment. [Figure 10] FIG. 2 is a schematic diagram illustrating a first application example of the path generation device according to the first embodiment. [Figure 11] FIG. 10 is a block diagram of a configuration of a path generating device according to the first embodiment, which is used in a second application example. [Figure 12] FIG. 10 is a schematic diagram illustrating a second application example of the path generation device according to the first embodiment. [Figure 13] FIG. 10 is a schematic diagram illustrating a second application example of the path generation device according to the first embodiment. [Figure 14] FIG. 10 is a schematic diagram illustrating a second application example of the path generation device according to the first embodiment. [Figure 15] FIG. 10 is a block diagram of a configuration of the path generating device according to the first embodiment, which is used in a third application example. [Figure 16] FIG. 10 is a flowchart illustrating a processing flow in a third application example of the path generation device according to the first embodiment. [Figure 17] FIG. 10 is a schematic diagram illustrating a third application example of the path generation device according to the first embodiment. [Figure 18] FIG. 10 is a schematic diagram illustrating a third application example of the path generation device according to the first embodiment. [Figure 19] FIG. 10 is a block diagram of a configuration of the path generation device according to the first embodiment, which is used in a fourth application example. [Figure 20] FIG. 10 is a flowchart illustrating a processing flow in a fourth application example of the path generation device according to the first embodiment. [Figure 21] FIG. 10 is a schematic diagram illustrating a fourth application example of the path generation device according to the first embodiment. [Figure 22] FIG. 10 is a functional block diagram showing the configuration of a parking assistance system according to a second embodiment. [Figure 23] FIG. 10 is a schematic diagram of a vehicle equipped with a parking assistance system according to a second embodiment. [Figure 24] 1 is a diagram showing a hardware configuration for realizing a route generation device according to a first embodiment and a parking assistance system according to a second embodiment. [Figure 25] 1 is a diagram showing a hardware configuration for realizing a route generation device according to a first embodiment and a parking assistance system according to a second embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0012] Embodiment 1 <Configuration of the path generation device according to the first embodiment> A block diagram of a route generation device 100 according to the first embodiment is shown in Fig. 1. The route generation device 100 is mounted on a vehicle.

[0013] The route generation device 100 includes a vehicle position acquisition unit 10, a surrounding environment information acquisition unit 11, a vehicle information acquisition unit 12, a parking space information calculation unit 13, and a route generation unit 14. The route generation unit 14 includes a reference route generation unit 21 and a local route generation unit 22.

[0014] <Vehicle position acquisition unit> The vehicle position acquisition unit 10 acquires the vehicle position and outputs the vehicle position to the route generation unit 14. One example of the means for acquiring the vehicle position by the vehicle position acquisition unit 10 is a GNSS receiver that receives signals transmitted from a GNSS (Global Navigation Satellite System) such as a GPS (Global Positioning System) to acquire information on the absolute position (latitude, longitude). Alternatively, the vehicle position may be detected by a speed sensor, a direction sensor, or the like.

[0015] <Surrounding Environment Information Acquisition Department> The surrounding environment information acquisition unit 11 acquires surrounding environment information of the host vehicle 1 using various sensors mounted on the host vehicle 1, and outputs the information to the route generation unit 14. Methods for acquiring the surrounding environment information include a method of detecting an obstacle 38 by measuring the distance between the obstacle 38 and the host vehicle 1 using a sonar sensor, and a method of detecting an obstacle 38 around the host vehicle using a high-precision sensor such as LiDAR (Light Detection And Ranging). Alternatively, the surrounding environment information may be image information obtained from at least one or more in-vehicle cameras mounted on the host vehicle 1 that capture images of the area around the host vehicle. It is also possible to detect the position of the imaged obstacle 38 from the image information.

[0016] <Vehicle Information Acquisition Unit> The vehicle information acquisition unit 12 acquires vehicle information, which is information about the host vehicle 1, and outputs it to the route generation unit 14. The vehicle information includes state quantities of the host vehicle 1 that indicate the state of the host vehicle 1. Examples of the vehicle information include the vehicle speed from the wheel speed pulse sensor, the yaw rate from the yaw rate sensor, the pitch angle and roll angle from the gyro sensor, etc. In addition, the vehicle information acquired includes the amount of depression of the accelerator pedal when the user depresses it during manual driving, the status of past parking assistance operations, and the like.

[0017] <Parking space information calculation unit> The parking space information calculation unit 13 detects the parking space 40, calculates the parking target position 45 and drivable area 41 of the vehicle 1 as parking space information, and outputs the parking space information to the path generation unit 14. In other words, the parking space information calculation unit 13 detects the parking space 40 from the surrounding environment information around the vehicle 1 and the vehicle position, and sets the parking target position 45.

[0018] The parking space information calculation unit 13 determines the aisle boundary 39 from the position of an obstacle 38 detected while the vehicle 1 is traveling on the road, and sets the area that combines the drivable aisle and the parking space 40 as the drivable area 41. If there is no obstacle 38 in the aisle, the drivable area 41 is set to a certain distance from the vehicle 1 as the upper limit.

[0019] 2 and 3 are schematic diagrams illustrating the operation of the path generation device 100 according to the embodiment 1. As shown in Fig. 2, when the host vehicle 1 passes in front of a target parking space 40, the surrounding environment information acquisition unit 11 detects an adjacent vehicle 2 adjacent to the parking space 40 as an obstacle 38, and sets a space that is larger than the host vehicle 1 by a certain width or more as the parking space 40.

[0020] The parking target position 45 indicates the position of the vehicle 1 and the attitude angle of the vehicle 1 when parking is completed, and the target attitude angle may be set in accordance with the direction of the adjacent vehicle 2, or may be set according to the direction of the aisle.

[0021] 3, a section with a white line 46 drawn on it, captured by an on-board camera, can also be set as the parking space 40. When using the white line 46, the area other than the area where the obstacle 38 and adjacent vehicle 2 exist is set as the drivable area 41, and the area outside the parking space 40 that extends beyond the white line 46 is also set as the drivable area 41.

[0022] <Route Generation Unit> The route generation unit 14 generates a route from a parking start position 44 to a parking target position 45 based on the vehicle position, surrounding environment information, vehicle information, and parking space information. The route generation unit 14 is made up of a reference route generation unit 21 and a local route generation unit 22.

[0023] <Reference path generation section> The reference path generation unit 21 generates a reference path 51, which is an overall path for parking the vehicle 1 from the parking start position 44 to the parking target position 45, based on the parking space information. The reference path 51 is composed of a combination of any curves. Examples of curves include straight lines, clothoid curves, and circular arc curves. The reference path 51 can also be generated to satisfy various constraints such as parking space information, obstacles 38, and vehicle performance.

[0024] In the route search, i.e., generation, of the reference route 51, an evaluation function including the route length, steering amount, number of turns, etc. is used, and the route that minimizes the evaluation function is output as the optimal route for parking. Note that the route generation method is not limited to this method, and a graph search method, etc., may also be used. Furthermore, the reference route 51 outputs a route that includes multiple turns as necessary.

[0025] <Local Route Generation Unit> When the local path generation unit 22 controls the vehicle 1 so that it follows the reference path 51 from its current vehicle position, the local path generation unit 22 estimates a future position at a predetermined distance interval to generate a travel trajectory (movement trajectory) that the vehicle 1 will actually travel from its current vehicle position as the local path 52. In other words, the local path generation unit 22 generates the local path 52 as a movement trajectory that converges from the current position to the reference path 51 at the current position while the vehicle 1 is moving along the reference path 51. One example of generating the local path 52 is a method of generating a movement trajectory by estimating a future position at a predetermined distance interval.

[0026] The local route 52 is generated and updated periodically during guidance by parking control, i.e., at predetermined time intervals or predetermined travel distance intervals. In other words, if the host vehicle 1 virtually or actually stops multiple times along the reference route 51, a local route 52 including a future position is generated at each stopping position. In the following description, the stopping position does not only refer to a realistic stopping position, but also includes a position where the vehicle actually moves almost continuously but is considered to have stopped virtually. In short, the stopping positions can be said to be each point at which the local route 52 is generated. This concludes the description of each component of the path generating device 100 according to the first embodiment.

[0027] <First application example of the path generation device> A first application example of the path generation device 100 will be described below, but application examples of the path generation device are not limited to the following first to fourth application examples. 4 and 5 are schematic diagrams illustrating a first application example of the route generation device 100. The first application example of the route generation device 100 will be described with reference to Fig. 4 and Fig. 5. The first application example is applied to the case of parallel backward entry.

[0028] At the start of the parking path, the reference path generating unit 21 of the path generating device 100 generates a reference path 51 from the parking start position 44 to the parking target position 45. When generating the reference path 51, a path with one step is generated.

[0029] When the vehicle position deviates from the reference route 51, the local route generation unit 22 generates a local route 52. The vehicle 1 calculates the remaining distance based on the local route 52, and calculates the driving route length to the parking target position 45. The above is the basic operation of the first application example of the path generation device 100. The operation of the first application example of the path generation device 100 will be described in more detail below.

[0030] If the current position of the vehicle 1 deviates from the reference route 51, the driving path length when guiding the vehicle from the deviated position to the parking target position 45 may differ from the driving path length assumed in the reference route 51.

[0031] Therefore, the path generation device 100 generates a local path 52 and calculates in advance with high accuracy the remaining travel distance to the parking target position 45, i.e., the remaining distance. The remaining distance means the travel distance from the current vehicle position (current stop position) to the next stop position (target position) when the vehicle 1 actually or virtually stops at a predetermined travel distance interval along the reference path 51. There are various factors that cause the vehicle position to deviate from the reference path 51, but FIG. 4 shows an example in which there is a delay in steering angle control.

[0032] FIG. 5 also shows a case where the parking target position 45 and the pre-update reference route 51a are updated to the updated reference route 51b during guidance due to factors such as the accuracy of the vehicle's position or the detection accuracy of the obstacle 38, resulting in the vehicle's position deviating from the pre-update reference route 51a.

[0033] In both cases shown in FIG. 4 and FIG. 5, a difference occurs between the remaining distance on the reference route 51 and the remaining distance to be actually traveled, resulting in a decrease in accuracy when parking is completed.

[0034] In such a situation, the route generation device 100 generates the local route 52 and calculates the remaining distance to be actually traveled, thereby controlling the vehicle speed so that the vehicle can be stopped at the parking target position 45 with high accuracy.

[0035] Furthermore, when estimating a future position using the local route 52, by taking into consideration the vehicle speed control characteristics, steering angle control characteristics, etc., it is possible to calculate a local route 52 that is close to the route to be traveled in the future.

[0036] The generation of the reference path 51 and the local path 52 by the path generation device 100 is not limited to the parking method (parallel / parallel, forward / backward), etc. In addition, it can be applied not only to the parking entry operation but also to the parking exit operation, and also to the case of performing parking control such as entering the parking space 40 while detecting the parking space 40.

[0037] <Route Generation Method Using Route Generation Device in First Application Example> The processing flow by the route generation device in the first application example, that is, the route generation method, will be explained below using the flowcharts in Figures 6 and 7. Steps S101 to S106 will be explained using the flowchart in Figure 6, and steps S111 to S117 will be explained using the flowchart in Figure 7.

[0038] First, in step S101, the surrounding environment information acquisition unit 11 acquires surrounding environment information around the host vehicle. For example, the position of an obstacle 38 that may obstruct driving is detected by an in-vehicle camera mounted on the host vehicle 1, and the position is stored as surrounding environment information.

[0039] In step S102, the host vehicle position acquisition unit 10 acquires the current host vehicle position of the host vehicle 1.

[0040] In step S103 , the vehicle information acquisition unit 12 acquires vehicle information relating to the host vehicle 1 .

[0041] In step S104, the parking space information calculation unit 13 detects the parking space 40 and calculates the parking target position 45 and drivable area 41 of the host vehicle 1 as parking space information. That is, the parking space information calculation unit 13 detects the parking space 40 based on the surrounding environment information around the host vehicle and the host vehicle position, and sets the parking target position 45 within the parking space 40.

[0042] In step S105, the reference path generation unit 21 generates an entire path for parking the vehicle 1 from the parking start position 44 to the parking target position 45 as a reference path 51 based on the parking space information, as schematically shown in Figure 8.

[0043] In step S106, as shown in Fig. 9, when the local route generation unit 22 controls the vehicle 1 so that it follows the reference route 51 from the current vehicle position, the local route generation unit 22 estimates the future position of each travel section provided at a predetermined distance interval, thereby generating a travel trajectory (movement trajectory) along which the vehicle 1 will actually travel from the current vehicle position as a local route 52. The processing flow of the local route generation will be described in detail using the flowchart in Fig. 7.

[0044] In step S111, a tentative remaining distance to be traveled in the current travel section is calculated based on the route length of the current travel section based on the reference route 51 and the travel distance traveled by the vehicle 1 in the current travel section, or the remaining distance calculated last time, and the distance interval for estimating the future position is set according to the length of the tentative remaining distance. For example, if the tentative remaining distance is long, the estimated distance interval is set large to reduce the calculation load, while if the tentative remaining distance is short, the estimated distance interval is set small, allowing the remaining distance to be calculated with high accuracy. Furthermore, if the vehicle deviates from the route, the remaining distance until the next stopping position is reached may be longer than the provisional remaining distance, so the distance interval for estimating the future position is set so that the remaining distance when the future position is estimated until the maximum number of loops is reached is longer than the provisional remaining distance.

[0045] In step S112, a target curvature for following the reference path 51 is calculated based on the position deviation between the current vehicle position and the reference path 51, with the current vehicle position as the starting point. A publicly known technique may be used as a method for controlling following of the reference path 51. One example of the publicly known technique is a method for calculating the target curvature while suppressing a sudden change in the vehicle attitude angle, using the technique disclosed in Japanese Patent Application Laid-Open No. 2017-88112. However, the method for generating the travel path is not particularly limited.

[0046] In step S113, the future position and vehicle attitude angle of the host vehicle 1 when the host vehicle 1 has traveled a predetermined distance according to the target curvature are calculated. When calculating the future position, vehicle information, vehicle speed control conditions, and vehicle steering control characteristics such as maximum steering angle, maximum steering speed, and steering angle delay may be reflected.

[0047] In step S114, the position deviation between the calculated future position and the target position is calculated, and it is determined that the target position has been reached if the position deviation is less than a threshold. As described above, the target position refers to the next stopping position on the reference path 51. The position deviation between the future position and the target position is determined by calculating the vehicle length direction position deviation, vehicle width direction position deviation, and attitude angle deviation based on the orientation of the host vehicle 1 at the target position, and performing threshold determination. It may also be determined that the target position has been reached if at least one of the vehicle length direction position deviation, vehicle width direction position deviation, and attitude angle deviation, which are schematically shown in FIG. 10, is less than a threshold. The determination condition for determining that the target position has been reached may be the time when the host vehicle 1 is closest to the target position, or the time when the host vehicle 1 has passed the target position.

[0048] In step S115, it is determined whether or not the upper limit number of loops has been performed. If it is determined that the upper limit number of loops has not been performed, the processes from step S111 to step S115 are repeated. If it is determined in step S115 that the upper limit number of loops has been performed, the process proceeds to step S116.

[0049] In step S116, if it is determined in step S114 that the target position has been reached, the target position is set as the next stop position. On the other hand, in step S116, if it is determined in step S115 that the upper limit of loop counts has been performed, the target position at the time the upper limit of loop counts has been reached is set as the next stop position.

[0050] By repeating the processes from step S111 to step S115, the calculation of the future position is repeated until the next stop position is set, and thus the local route 52 is generated.

[0051] In step S117, the remaining distance from the current vehicle position (current stop position) to the next stop position is calculated based on the local route 52 and output. The above is the processing flow of the operation of the route generation device 100 in the first application example, that is, the route generation method.

[0052] <Characteristics and Effects of the First Application Example of the Path Generation Device> The first application example is characterized in that the number of steps is one, and the remaining distance to the target position is calculated by setting the position where the position deviation between the current vehicle position and the target position is less than a threshold as the stopping position.

[0053] The first application example has the following advantages. (1) Even if a deviation from the reference path 51 occurs due to a steering delay or the like, it is possible to recover. (2) Even if a deviation from the reference path 51 occurs due to a change in the target position and the reference path 51 being updated, it is possible to recover. (3) It is possible to calculate the future position in a way that reflects the steering control characteristics.

[0054] <Second application example of the path generation device> A second application example of the route generation device will be described below. First, the configuration of the route generation device 200 used in the second application example will be described. FIG. 11 is a block diagram of the route generation device 200 according to the first embodiment, which is used in the second application example. In addition to the configuration of the route generation device 100, the route generation device 200 further has a stop position setting unit 23 inside the local route generation unit 22.

[0055] The stop position setting unit 23 is a part of the local route generating unit 22, and sets the next stop position of the host vehicle 1 based on the local route 52 generated at the current stop position of the host vehicle.

[0056] 12, 13, and 14 are schematic diagrams each illustrating a second application example of the path generation device 200. The second application example is applied to the case of parallel forward entry into storage.

[0057] At the start of the parking path, the reference path generating unit 21 of the path generating device 200 generates a reference path 51 from the parking start position 44 to the parking target position 45. As shown in FIG. 12 , in the second application example, when generating the reference path 51, a path with two steps is generated.

[0058] When the vehicle position deviates from the reference route 51, the local route generation unit 22 generates a local route 52. The vehicle 1 calculates the remaining distance based on the local route 52, and calculates the driving route length to the parking target position 45.

[0059] The above is the basic operation of the second application example of the path generation device 200. The operation of the second application example of the path generation device 200 will be described in more detail below.

[0060] The processing flow of the second application example, i.e., the route generation method, is almost the same as the processing flow of the first application example shown in the flowcharts of Figures 6 and 7, but the content of the processing of step S114 is partially different. The following description will be limited to the processing of step S114.

[0061] In step S114, in determining whether the vehicle has reached the target position, the determination method may be switched between the case where the next stop position is the turning position 48 and the case where the next stop position is the parking target position 45. For example, if the next stop position is the turning position 48, threshold determination is performed using only the attitude angle deviation, and if the next stop position is the parking target position 45, threshold determination is performed using all of the vehicle length direction position deviation, vehicle width direction position deviation, and attitude angle deviation.

[0062] Depending on the constraints of the parking space 40 or the parking method, the route may require multiple turns. The reference route 51 is the entire route from the parking start position 44 to the parking target position 45, and the local route 52 is generated as a route for one distance interval from the current vehicle position (current stopping position) to the next stopping position in order to calculate the remaining distance to the next stopping position.

[0063] However, as long as the processing load allows, a multi-step route including a turn from the current vehicle position 49 to the parking target position 45 may be generated as the local route 52. In the processing of step S114, as described above, the determination of whether the target position has been reached when turning may be made based only on the target attitude angle deviation.

[0064] 13 and 14, when performing parallel forward parking, if there is a large attitude angle deviation between a target attitude angle and an actual attitude angle at a turning position 48 in the passage, the vehicle 1 may interfere with the outside of the drivable area 41 and may not be able to enter the parking space 40 in one step. Therefore, by prioritizing the attitude angle deviation over the position deviation when determining whether the vehicle has reached the target position, the opportunity to follow the reference path 51 within the drivable area 41 can be increased.

[0065] In the steps of guiding the vehicle 1 to the parking target position 45, since the position accuracy is involved, the method of determining whether the target position has been reached may be switched for each step, such as by determining whether the target position has been reached, including the position deviation.

[0066] <Characteristics and Effects of the Second Application Example of the Path Generation Device> The second application example is characterized in that the number of steps is two, and the remaining distance to the target position is calculated using a position where the position deviation between the current vehicle position and the target position or the attitude angle deviation between the current attitude angle and the target attitude angle is less than a threshold value as the stopping position.

[0067] The second application example has the following advantages. (1) Even if a deviation from the reference path 51 occurs due to a steering delay or the like, it is possible to recover. (2) Even if a deviation from the reference path 51 occurs due to a change in the target position and the reference path 51 being updated, it is possible to recover. (3) It is possible to calculate the future position in a way that reflects the steering control characteristics. (4) By prioritizing the adjustment of the vehicle attitude angle, guidance becomes easier.

[0068] <Third application example of the path generation device> A third application example of the route generation device will be described below. First, the configuration of route generation device 300 used in the third application example will be described. FIG. 15 is a block diagram of route generation device 300 according to the first embodiment, which is used in the third application example. In addition to the configuration of route generation device 200, route generation device 300 further includes a residual distance calculation unit 24 inside local route generation unit 22.

[0069] The remaining distance calculation unit 24 is part of the local route generation unit 22, and calculates the remaining distance, which is the travel distance from the current vehicle position (current stop position) to the next stop position, based on the generated local route 52.

[0070] A processing flow by the route generation device in the third application example, that is, a flowchart showing a route generation method, is shown in Fig. 16. Figs. 17 and 18 are schematic diagrams each explaining a third application example of the route generation device 300. The third application example is applied to the case of parallel backward entry.

[0071] At the start of the parking path, the reference path generating unit 21 of the path generating device 300 generates a reference path 51 from the parking start position 44 to the parking target position 45. As shown in Fig. 17, when generating the reference path 51, a path with one step is generated.

[0072] When the vehicle position deviates from the reference route 51, the local route generation unit 22 generates a local route 52. The remaining distance calculation unit 24 calculates the remaining distance based on the local route 52, and calculates the driving route length to the parking target position 45. The above is the basic operation of the third application example of the path generation device 300. The operation of the third application example of the path generation device 300 will be described in more detail below.

[0073] <Route generation method using the route generation device in the third application example> In the processing flow of the third application example, that is, in the route generation method, the processing of step S121 is added between the processing of step S113 and step S114 in the processing flow of the second application example, and part of the processing content of step S116 is added, as shown in the flowchart of the third application example in Fig. 16. Only the parts that differ from the processing flow of the second application example will be explained below.

[0074] In step S121, it is determined whether the host vehicle 1 will interfere with an obstacle 38 or a travel-prohibited area at its future position. In the interference determination, the minimum distance that the host vehicle 1 is allowed to approach the obstacle 38 may be set as a safety margin for parking control purposes, and an area including the safety margin from the vehicle edge may be determined as a safety margin area 47.

[0075] In step S116, the position where it is determined that the vehicle 1 will interfere with the obstacle 38 or the position where it is determined that the vehicle 1 has reached the target position is set as the next stopping position. At the position where it is determined that the vehicle 1 will interfere with the obstacle 38, a position a predetermined distance before the interference position may be set as the next stopping position so that the interference does not actually occur.

[0076] If the host vehicle 1 deviates from the route, there is a possibility that the host vehicle 1 will interfere with a non-drivable area that is not a drivable area 41, as shown schematically in FIG. 17, or that an obstacle 38 will be detected near the route, as shown schematically in FIG. 18. When generating the local route 52, it is determined whether the host vehicle 1 will interfere with the obstacle 38, and the travel distance to the position where it is determined that interference will occur is calculated as the remaining distance. By outputting the distance to the position where interference may occur as the remaining distance in advance, it is possible to control the vehicle speed of the host vehicle 1 with respect to the obstacle 38 from a closer distance.

[0077] According to the third application example, the following effects are obtained. (1) Even if a deviation from the reference path 51 occurs due to a steering delay or the like, it can be corrected. (2) Even if a deviation from the reference path 51 occurs due to a change in the target position and the reference path 51 being updated, it can be corrected. (3) It is possible to calculate the future position in a way that reflects the steering control characteristics. (4) When the vehicle interferes with an obstacle 38, the remaining distance to the interference position is calculated, making it possible to prevent sudden deceleration.

[0078] <Fourth application example of the path generation device> A fourth application example of the route generation device will be described below. First, the configuration of route generation device 400 used in the fourth application example will be described. FIG. 19 is a block diagram of route generation device 400 according to the first embodiment, which is used in the fourth application example. In addition to the configuration of route generation device 300, route generation device 400 further has a control stop determination unit 25 inside local route generation unit 22.

[0079] The control termination determination unit 25 is part of the local route generation unit 22, and calculates the distance deviation between the local route 52 and the reference route 51, and if the distance deviation is greater than or equal to a predetermined distance, determines that parking control of the vehicle 1 should be terminated.

[0080] The processing flow by the route generation device in the fourth application example is shown in the flowchart of Fig. 20. Fig. 21 is a schematic diagram showing the fourth application example of the route generation device 400. The fourth application example is applied to the case of parallel backward entry.

[0081] At the start of the parking path, the reference path generating unit 21 of the path generating device 400 generates a reference path 51 from the parking start position 44 to the parking target position 45. As shown schematically in Fig. 21, when generating the reference path 51, a path with one step is generated.

[0082] When the vehicle position deviates from the reference route 51, the local route generation unit 22 generates a local route 52. The remaining distance calculation unit 24 calculates the remaining distance based on the local route 52, and calculates the driving route length to the parking target position 45. The above is the basic operation of the fourth application example of the path generation device 400. The operation of the fourth application example of the path generation device 400 will be explained in more detail below.

[0083] <Route generation method using the route generation device in the fourth application example> In the processing flow of the fourth application example, that is, the route generation method, the processing of step S131 is added after the processing of step S117 in the processing flow of the third application example, as shown in the flowchart of Fig. 20. Only the parts that differ from the processing flow of the third application example will be explained below.

[0084] If the host vehicle 1 is being guided in a direction deviating from the route, or if it is determined that the deviation from the route is so great that the host vehicle 1 cannot keep up with the route, the route generation device 400 halts parking control. For example, as schematically shown in Fig. 21, if it is determined that it is difficult to converge the local route 52 onto the reference route 51 even though the host vehicle 1 has generated a local route 52 because the deviation from the route of the host vehicle 1 is so great that the control halt determination unit 25 determines that it is difficult to guide the host vehicle 1 to the parking target position 45 and therefore determines to halt parking control.

[0085] Also, as shown schematically in FIG. 18, if the vehicle is stopped due to an obstacle interference determination because an obstacle 38 exists near the reference route 51 within the drivable area 41, the parking control is interrupted, and if the vehicle continues to be stopped due to the obstacle interference determination for a certain period of time and it is difficult to guide the vehicle to the parking target position 45, it is determined that the parking control is to be discontinued.

[0086] According to the fourth application example, the following effects are obtained. (1) Even if a deviation from the reference path 51 occurs due to a steering delay or the like, it can be corrected. (2) Even if a deviation from the reference path 51 occurs due to a change in the target position and the reference path 51 being updated, it can be corrected. (3) It is possible to calculate the future position in a way that reflects the steering control characteristics. (4) If the deviation from the route is large, parking control is stopped.

[0087] <Advantages of First Embodiment> The advantages achieved by the route generation device and route generation method according to the first embodiment are listed below. (1) By generating a local route, even if the vehicle position deviates from the target position, it is possible to generate a route that takes into account the deviation from the current vehicle position to the target position. (2) In particular, by accurately calculating the travel distance (remaining distance) from the current vehicle position to the next stopping position based on the local route, it is possible to accurately guide the vehicle to the target position even if the vehicle position deviates from the target route. (3) By continuously updating the remaining distance to the target position or obstacle and controlling the vehicle speed according to the remaining distance, sudden deceleration can be suppressed, enabling the vehicle to stop safely. (4) Even if the target position or parking space information is recalculated during guidance, the remaining distance can be calculated accurately.

[0088] Embodiment 2 <Configuration of parking assistance system according to embodiment 2> 22 is a block diagram showing the configuration of a parking assistance system 500 according to the second embodiment. The parking assistance system 500 according to the second embodiment includes the route generation device 100 according to the first embodiment and a vehicle control device 501. Note that the route generation device may be any of the route generation devices 200, 300, and 400 other than the route generation device 100 according to the first embodiment.

[0089] The vehicle control device 501 performs vehicle control to park the vehicle 101a in the parking space 40 based on the route information output from the route generation unit 14 of the route generation device 100. The vehicle control device 501 calculates a target steering amount in accordance with the target curvature generated by the route generation unit 14, and parks the vehicle 101a with high accuracy at a target parking position 45 within the parking space 40 by automatic driving. In addition, the vehicle control device 501 calculates a target acceleration / deceleration based on the remaining distance generated by the route generation unit 14, and smoothly guides the vehicle 101a to the target parking position 45 within the parking space 40.

[0090] The target steering amount and the target acceleration / deceleration in the vehicle control device 501 can be calculated using a known calculation method such as a calculation method using feedback control or a calculation method using MPC (Model Predictive Control).

[0091] The actuator 530 includes an Electronic Power Steering (EPS) unit 535, a powertrain unit 536, a brake unit 537, an EPS controller 531, a powertrain controller 532, and a brake controller 533. The actuator 530 controls the EPS, the brake, and the accelerator so that the vehicle 101a follows a target steering amount and a target acceleration / deceleration.

[0092] The vehicle control device 501 then processes information input from various connected sensors (not shown) according to a program stored in ROM, transmits a target control amount to the EPS controller 531, transmits a target driving force to the powertrain controller 532, and transmits a target braking force to the brake controller 533.

[0093] The EPS controller 531 controls the EPS unit 535 based on the target control amount transmitted from the vehicle control device 501. The EPS controller 531 can control, for example, the steering angle so that the vehicle 101a travels along a target trajectory.

[0094] The powertrain controller 532 controls the powertrain unit 536 so as to realize the target driving force transmitted from the vehicle control device 501 .

[0095] In the description of the second embodiment, a vehicle using only an engine as a driving force source is given as an example, but the present invention may also be applied to a vehicle using only an electric motor as a driving force source, or a vehicle using both an engine and an electric motor as a driving force source.

[0096] The brake controller 533 controls the brake unit 537 so as to realize the target braking force transmitted from the vehicle control device 501 . The above is an outline of the configuration of the parking assistance system 500 including the route generation device 100 and the vehicle control device 501.

[0097] 23 is a schematic diagram of a vehicle 101a equipped with a parking assistance system 500 according to embodiment 2. The parking assistance system 500 and an actuator 530 are installed in the vehicle 101a.

[0098] <Advantages of the Second Embodiment> As described above, according to the parking assistance system of embodiment 2, route generation is performed using one of the route generation devices of embodiment 1, thereby achieving the effect of realizing parking with high positional accuracy through highly stable automatic driving control.

[0099] The above has described a configuration in which the functions of each component of the path generation devices 100, 200, 300, and 400 according to the first embodiment and the parking assistance system 500 according to the second embodiment are realized by either hardware or software, etc. However, the present invention is not limited to this, and the path generation devices 100, 200, 300, and 400 and the parking assistance system 500 may be configured such that some of the components are realized by dedicated hardware and other components are realized by software, etc.

[0100] For example, as shown in Figures 24 and 25, the functions of some components can be realized by a processing circuit 800 as dedicated hardware, and the functions of other components can be realized by the processing circuit 800 as a processor 801 reading and executing a program stored in a memory device 802 for executing the route generation method of embodiment 1 on a computer or the like.

[0101] Furthermore, as shown in FIG. 25, the setting data used by each functional unit of the route generation devices 100, 200, 300, 400 and the parking assistance system 500 may be installed in the storage device 802 from a recording medium 803 that stores a part of the software, i.e., a program 804 for executing the route generation method of embodiment 1 on a computer or the like.

[0102] As described above, the path generation devices 100, 200, 300, and 400 according to the first embodiment and the parking assistance system 500 according to the second embodiment can realize the above-described functions by hardware, software, or a combination of these.

[0103] <Summary of various aspects of the present application> Various aspects of the present application will be summarized below as appendices.

[0104] (Appendix 1) a vehicle position acquisition unit that acquires the vehicle position; a surrounding environment information acquisition unit that acquires surrounding environment information of the host vehicle; a vehicle information acquisition unit that acquires vehicle information of the host vehicle; a parking space information calculation unit that detects a parking space and calculates a parking target position and a drivable area of ​​the vehicle as parking space information; a route generation unit that generates a route for the host vehicle to travel based on the host vehicle position, the surrounding environment information, the vehicle information, and the parking space information; The path generation unit a reference path generating unit that generates a reference path from a parking start position to the parking target position; a local route generation unit that generates, at a current position of the host vehicle while the host vehicle is moving along the reference route, a local route that is a movement trajectory that converges from the current position to the reference route; A route generation device comprising:

[0105] (Appendix 2) The route generation device described in Appendix 1, wherein the local route generation unit further includes a stop position setting unit that sets the next stop position of the host vehicle based on the local route generated at the current stop position of the host vehicle when the host vehicle stops multiple times along the reference route.

[0106] (Appendix 3) the stop position setting unit calculates a position deviation and an attitude angle deviation between a current stop position and a vehicle attitude angle of the host vehicle used when generating the local path, and a target stop position and a target attitude angle at a next stop position along the reference path, 3. The path generation device according to claim 2, wherein a position on the local path where at least one of the position deviation and the attitude angle deviation is less than a threshold value is set as the next stopping position.

[0107] (Appendix 4) The path generation device according to claim 2, wherein, when a next stop position of the host vehicle along the reference path is a turning position, the stop position setting unit sets, as the next stop position, a position on the local path where at least one of a vehicle attitude angle and a position deviation and an attitude angle deviation of the vehicle attitude angle when turning is less than a threshold value.

[0108] (Appendix 5) The stop position setting unit determining whether or not a no-travel area or an obstacle based on the parking space information and the surrounding environment information interferes with the host vehicle at each position when the host vehicle moves along a local route; The route generation device described in Appendix 2 is characterized in that, when it is determined that the vehicle will interfere with a non-traveling area or an obstacle, a position on the local route a predetermined distance before the position of interference is set as the next stopping position.

[0109] (Appendix 6) The route generation device according to any one of Supplementary Notes 1 to 5, wherein the local route generation unit further includes a remaining distance calculation unit that calculates a remaining distance, which is a travel distance from the current position of the vehicle to the next stopping position, based on the generated local route.

[0110] (Appendix 7) The route generation device according to any one of appendixes 1 to 6, wherein the local route generation unit reflects steering angle control characteristics included in the vehicle information when calculating a future vehicle position.

[0111] (Appendix 8) The route generation device according to any one of Supplementary Notes 1 to 7, wherein the local route generation unit further includes a control cancellation determination unit that calculates a distance deviation between the local route and the reference route, and determines to cancel parking control of the host vehicle if the distance deviation is equal to or greater than a predetermined distance.

[0112] (Appendix 9) A path generation device according to any one of Supplementary Notes 1 to 8; a vehicle control device that parks the vehicle in the parking space based on the route information generated by the route generation unit; A parking assistance system equipped with

[0113] (Appendix 10) A route generation method for generating a route for a vehicle to travel from a parking start position to a parking target position, comprising: generating a reference path from the parking start position to the parking target position; generating, at a current position of the host vehicle while the host vehicle is moving along the reference route, a local route that is a movement trajectory that converges from the current position to the reference route; When the host vehicle stops multiple times along the reference route, setting a next stop position of the host vehicle based on a local route generated at a current stop position of the host vehicle; A route generation method comprising:

[0114] (Appendix 11) calculating a position deviation and an attitude angle deviation between a current stop position and a vehicle attitude angle of the host vehicle used when generating the local path and a target stop position and a target attitude angle at a next stop position along the reference path; setting a position on the local path where at least one of the position deviation and the attitude angle deviation is less than a threshold as a next stop position; 11. The route generation method according to claim 10, further comprising:

[0115] Although the present disclosure describes various exemplary embodiments and examples, the various features, aspects, and functions described in one or more embodiments are not limited to application to a particular embodiment, but may be applied to the embodiments alone or in various combinations.

[0116] Therefore, countless variations not illustrated are conceivable within the scope of the technology disclosed in the present specification, including, for example, cases where at least one component is modified, added, or omitted, and cases where at least one component is extracted and combined with components of another embodiment. [Explanation of symbols]

[0117] 1 Vehicle, 2 Adjacent vehicle, 10 Vehicle position acquisition unit, 11 Surrounding environment information acquisition unit, 12 Vehicle information acquisition unit, 13 Parking space information calculation unit, 14 Path generation unit, 21 Reference path generation unit, 22 Local path generation unit, 23 Stop position setting unit, 24 Remaining distance calculation unit, 25 Control termination determination unit, 38 Obstacle, 39 Passage boundary, 40 Parking space, 41 Drivable area, 44 Parking start position, 45 Parking target position, 46 White line, 47 Safety margin area, 48 Turning position, 49 Current vehicle position, 51 Reference path, 51a Reference path before update, 51b Reference path after update, 52 Local path, 100, 200, 300, 400 Path generation device, 500 Parking assistance system, 501 Vehicle control device, 530 Actuator, 531 EPS controller, 532 Power train controller, 533 brake controller, 535 EPS unit, 536 power train unit, 537 brake unit, 800 processing circuit, 801 processor, 802 storage device, 803 recording medium, 804 program

Claims

1. a vehicle position acquisition unit that acquires the vehicle position; a surrounding environment information acquisition unit that acquires surrounding environment information of the host vehicle; a vehicle information acquisition unit that acquires vehicle information of the host vehicle; a parking space information calculation unit that detects a parking space and calculates a parking target position and a drivable area of ​​the vehicle as parking space information; a route generation unit that generates a route for the host vehicle to travel based on the host vehicle position, the surrounding environment information, the vehicle information, and the parking space information; The path generation unit a reference path generating unit that generates a reference path from a parking start position to the parking target position; a local route generation unit that generates, at a current position of the host vehicle while the host vehicle is moving along the reference route, a local route that is a movement trajectory that converges from the current position to the reference route; Equipped with The local route generation unit is characterized in that, when the vehicle stops multiple times along the reference route, it includes a stop position setting unit that sets the next stop position of the vehicle based on the local route generated at the current stop position of the vehicle.

2. the stop position setting unit calculates a position deviation and an attitude angle deviation between a current stop position and a vehicle attitude angle of the host vehicle used when generating the local path, and a target stop position and a target attitude angle at a next stop position along the reference path, 2. The path generation device according to claim 1, wherein a position on the local path where at least one of the position deviation and the attitude angle deviation is less than a threshold value is set as the next stopping position.

3. 2. The path generation device according to claim 1, wherein, when a next stop position of the host vehicle along the reference path is a turning position, the stop position setting unit sets, as the next stop position, a position on the local path where at least one of a vehicle attitude angle and a position deviation and an attitude angle deviation of the vehicle attitude angle when turning is less than a threshold value.

4. The stop position setting unit determining whether or not a no-travel area or an obstacle based on the parking space information and the surrounding environment information interferes with the host vehicle at each position when the host vehicle moves along a local route; The route generation device according to claim 1, characterized in that, when it is determined that the vehicle will interfere with a non-traveling area or an obstacle, a position on the local route a predetermined distance before the position of interference is set as the next stopping position.

5. A vehicle position acquisition unit that acquires the vehicle position; a surrounding environment information acquisition unit that acquires surrounding environment information of the host vehicle; a vehicle information acquisition unit that acquires vehicle information of the host vehicle; a parking space information calculation unit that detects a parking space and calculates a parking target position and a drivable area of ​​the vehicle as parking space information; a route generation unit that generates a route for the host vehicle to travel based on the host vehicle position, the surrounding environment information, the vehicle information, and the parking space information; The path generation unit a reference path generating unit that generates a reference path from a parking start position to the parking target position; a local route generation unit that generates, at a current position of the host vehicle while the host vehicle is moving along the reference route, a local route that is a movement trajectory that converges from the current position to the reference route, The local route generation unit may further include a remaining distance calculation unit that calculates a remaining distance, which is a travel distance from the current position of the vehicle to a next stopping position, based on the generated local route.

6. 5. The route generation device according to claim 1, wherein the local route generation unit reflects steering angle control characteristics included in the vehicle information when calculating a future vehicle position.

7. A vehicle position acquisition unit that acquires the vehicle position; a surrounding environment information acquisition unit that acquires surrounding environment information of the host vehicle; a vehicle information acquisition unit that acquires vehicle information of the host vehicle; a parking space information calculation unit that detects a parking space and calculates a parking target position and a drivable area of ​​the vehicle as parking space information; a route generation unit that generates a route for the host vehicle to travel based on the host vehicle position, the surrounding environment information, the vehicle information, and the parking space information; The path generation unit a reference path generating unit that generates a reference path from a parking start position to the parking target position; a local route generation unit that generates, at a current position of the host vehicle while the host vehicle is moving along the reference route, a local route that is a movement trajectory that converges from the current position to the reference route, The local route generation unit calculates a distance deviation between the local route and the reference route, and if the distance deviation is equal to or greater than a predetermined distance, the route generation device further includes a control cancellation determination unit that determines to cancel parking control of the vehicle.

8. A path generation device according to any one of claims 1 to 5 and 7; a vehicle control device that parks the vehicle in the parking space based on the route information generated by the route generation unit; A parking assistance system equipped with

9. A route generation method for generating a route for a vehicle to travel from a parking start position to a parking target position, comprising: generating a reference path from the parking start position to the parking target position; generating, at a current position of the host vehicle while the host vehicle is moving along the reference route, a local route that is a movement trajectory that converges from the current position to the reference route; When the host vehicle stops multiple times along the reference route, setting a next stop position of the host vehicle based on a local route generated at a current stop position of the host vehicle; A route generation method comprising:

10. calculating a position deviation and an attitude angle deviation between a current stop position and a vehicle attitude angle of the host vehicle used when generating the local path and a target stop position and a target attitude angle at a next stop position along the reference path; setting a position on the local path where at least one of the position deviation and the attitude angle deviation is less than a threshold as a next stop position; The route generation method of claim 9 further comprising:

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