Route search device and route search method

Abstract

To provide a route search device capable of promoting the use of a road section where a user easily feels stress.SOLUTION: Based on the data of the plurality of drivers, the driver search unit 20 searches the plurality of drivers for a similar driver who feels stress from the stressor in a manner similar to that of the target driver. Subsequently, the allowable range estimation unit 21 estimates the allowable range of the target driver for the characteristic value of the stressor based on the stress data indicating the degree S of the stress felt by the similar driver during traveling in the road section for each characteristic value of the stressor existing in the road section traveled by the searched similar driver in the past. Subsequently, based on the estimated allowable range, the route search unit 22 searches for a travel route of the vehicle C e such that a road section in which the characteristic value of the stress factor is within the allowable range is traveled preferentially over a road section outside the allowable range.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present disclosure relates to a route search device and a route search method. [Background technology]

[0002] Conventionally, a vehicle control device has been proposed that determines whether a driver is under stress, and if so, identifies stress factors outside the vehicle from the direction of the driver's line of sight, and changes the vehicle's course to avoid the identified stress factors (see, for example, Patent Document 1). [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Patent Publication No. 2021-37795 Summary of the Invention [Problem to be solved by the invention]

[0004] However, with the vehicle control device described in Patent Document 1, for example, if the driver feels stressed due to a stress factor on the road, the vehicle's route may be changed to avoid that road. Therefore, once a road has caused stress, the driver may be permanently avoided. The present disclosure aims to provide a route search device and a route search method that can promote the use of road sections that are likely to cause stress. [Means for solving the problem]

[0005] A route search device according to one aspect of the present disclosure is a route search device that searches for a vehicle's driving route, and includes: a driver search unit that searches for a similar driver from among a plurality of drivers based on data of the plurality of drivers to find a similar driver who feels stress in response to stress factors in a manner similar to that of a target driver who is the driver of the vehicle; an acceptable range estimation unit that estimates the target driver's tolerance range for characteristic values ​​of stress factors based on stress data that indicates the degree of stress felt by the similar driver while driving on road sections on which the searched similar driver has previously driven, for each characteristic value of the stress factors present; and a route search unit that searches for a vehicle's driving route based on the estimated tolerance range so as to give priority to driving on road sections on which the characteristic values ​​of the stress factors are within the acceptable range over road sections on which the characteristic values ​​of the stress factors are outside the acceptable range.

[0006] In addition, a route search method of one aspect of the present disclosure is a route search method for searching for a vehicle's driving route, which searches for a similar driver from among the multiple drivers based on data of the multiple drivers who has a similar feeling of stress in response to stress factors to a target driver, who is a driver who feels stress in response to stress factors; estimates the target driver's tolerance range for the characteristic values ​​of stress factors based on stress data that indicates the degree of stress felt by the similar driver while driving on road sections that the searched similar driver has previously driven, for each characteristic value of the stress factors present in those road sections; and searches for a vehicle's driving route based on the estimated tolerance range so that road sections within which the characteristic values ​​of the stress factors are within the tolerance range are given priority over road sections outside the tolerance range. [Effects of the Invention]

[0007] According to the present disclosure, it is possible to provide a route search device and a route search method that can promote the use of road sections that tend to cause stress. [Brief explanation of the drawings]

[0008] [Figure 1] 1 is a diagram illustrating a schematic configuration of a route search device according to an embodiment. [Figure 2] FIG. 10 is a diagram showing an example of data of a plurality of drivers. [Figure 3] FIG. 10 is a diagram illustrating an example of stress data. [Figure 4] 4 is a flowchart showing the operation of the route search device. [Figure 5] FIG. 1 is a diagram illustrating a method for searching a vehicle's travel route. [Figure 6] 10 is a flowchart showing the processing content of a data accumulation and analysis process. [Figure 7] 10 is a flowchart showing the processing contents of a similar driver search process. [Figure 8] FIG. 10 is a diagram illustrating the processing content of a threshold setting process. [Figure 9] FIG. 10 is a diagram showing processing contents of a threshold setting process according to a modified example. DETAILED DESCRIPTION OF THE INVENTION

[0009] Hereinafter, embodiments of the present disclosure will be described with reference to the drawings. Note that the drawings are schematic and may differ from the actual embodiments. Furthermore, the embodiments of the present disclosure shown below are examples of devices and methods for embodying the technical ideas of the present disclosure, and the technical ideas of the present disclosure do not limit the structure, arrangement, etc. of the components to those described below. Various modifications can be made to the technical ideas of the present disclosure within the technical scope defined by the claims.

[0010] (composition) In this embodiment, as shown in Fig. 1, a case is illustrated in which the route search device and route search method of the present disclosure are applied to a route search device 1 that searches for a travel route Dr for a vehicle Ce and proposes the route Dr to a driver. Fig. 1 is a diagram showing a schematic configuration of the route search device 1 according to this embodiment. The route search device 1 includes a surrounding environment sensor 2, a driver sensor 3, a stress identification device 4, a personal database (DB) 5, a shared DB 6, and a navigation device . The surrounding environment sensor 2 detects objects (e.g., vehicles, pedestrians, roads) around the vehicle Ce. The surrounding environment sensor 2 may be, for example, an exterior camera 8, a LiDAR 9, or a radar 10 mounted on the vehicle Ce. The object detection results are output to the stress identification device 4. The driver sensor 3 detects the state of the driver of the vehicle Ce. As the driver sensor 3, for example, a driver camera 11 and a biometric sensor 12 can be used. The driver camera 11 is a camera that captures images including a facial image of the driver of the vehicle Ce. As the driver camera 11, for example, an infrared camera can be used. Furthermore, the biometric sensor 12 is a sensor that detects biometric information that indicates the biological state (e.g., emotional state) of the driver of the vehicle Ce. As the biometric sensor 12, for example, various sensors that detect heart rate, pulse rate, amount of sweat, electrocardiogram, brain waves, etc. can be used. The detection results of the driver's state, etc. are output to the stress identification device 4.

[0011] The stress identifying device 4 includes a stress estimation unit 13 and a factor identifying unit 14. The stress estimation unit 13 estimates the level of stress S felt by the driver when driving the vehicle Ce. Examples of stress include tension caused to the mind and body by external stimuli. One method for estimating the level of stress S is to measure the number of times the driver blinks per unit time based on a facial image of the driver obtained from the driver camera 11, and estimate the level of stress S according to the magnitude of the measured number of blinks. Another method is to estimate the driver's negative emotions (e.g., anxiety, contempt, disgust, anger, fear, discomfort, tension, sense of risk) based on the facial image of the driver obtained from the driver camera 11 and biometric information obtained from the biometric sensor 12, and estimate the level of stress S according to the magnitude of the estimated negative emotions. The factor identification unit 14 identifies the stress factors of the driver of the vehicle Ce. Examples of stress factors include narrow roads (road sections with narrow road widths) and objects around the vehicle Ce. As a method for identifying stress factors, for example, the road width is extracted from road section information obtained from the navigation device 7, and the extracted road width is determined to be the stress factor. Also, for example, the direction of the driver's line of sight is estimated based on a facial image obtained from the driver camera 11, and an object present in the estimated line of sight (an object detected by the surrounding environment sensor 2) is determined to be the stress factor.

[0012] The personal DB5 stores information (hereinafter also referred to as "similar driver information") indicating similar drivers to the driver of the vehicle Ce (hereinafter also referred to as "target driver"). Similar drivers include, for example, other drivers who, as shown in FIG. 2, feel stress in response to stress factors in a similar way to the target driver. In particular, drivers whose driving skills are slightly better than the target driver and drivers in whom more stress data than the target driver is stored are preferred. The personal DB5 also stores information (hereinafter also referred to as "tolerance information") indicating the target driver's tolerance range for the characteristic values ​​of stress factors. For example, if the stress factor is "narrow roads," the tolerance range stores a specific numerical value (e.g., 3.5 m) of the road width that the target driver can tolerate. The personal DB5 also stores the threshold of the tolerance range of the target driver (tolerance range threshold W TH The navigation device 7 stores and updates the similar driver information and the like in the personal DB 5.

[0013] The shared DB 6 stores data on multiple drivers. For example, as shown in FIG. 2, the data on multiple drivers may include one or more of a stress value for each driver, a stress value for each object, and driver characteristics. FIG. 2 illustrates an example in which the stress value for each road is the stress level S associated with the width of the road. The shared DB 6 also stores stress data on multiple drivers. For example, as shown in FIG. 3, the stress data may include data indicating the stress level S felt by the driver while traveling along a road section traveled by the driver, for each characteristic value (e.g., road width) of a stress factor present in the road section traveled by the driver in the past. FIG. 3 illustrates an example in which the stress level S felt by the driver while traveling along the road section is used for each road width (e.g., 3.5 m, 3 m, ...) of the road section. For example, the road section may be represented by a link used to represent a road network in a digital road map. The data on multiple drivers (excluding the target driver) is stored and updated in the shared DB 6 via wireless communication with a server device (not shown). Furthermore, the storage and updating of data on the target driver in the shared DB 6 is performed by the navigation device 7.

[0014] As shown in FIG. 1, the navigation device 7 includes a positioning unit 15, a map storage unit 16, and a route calculation unit 17. The positioning unit 15 detects the vehicle Ce's own position. For example, a GPS (Global Positioning System) receiver that receives radio waves from multiple navigation satellites to measure the current position of the vehicle Ce can be used as the positioning unit 15. The detection result of the vehicle Ce's own position is output to the route calculation unit 17. The map storage unit 16 stores road map data. For example, a navigation map that can be used to calculate a driving route Dr from the current position of the vehicle Ce to a destination can be used as the road map data. The road map data also includes information on the road width of each road section.

[0015] The path calculation unit 17 includes a processor 18 and peripheral components such as a storage device 19 that stores computer programs and the like. The processor 18 may be, for example, a CPU (Central Processing Unit) or an MPU. The storage device 19 may be, for example, a semiconductor storage device, a magnetic storage device, or an optical storage device. The storage device 19 may include memories such as a register, a cache memory, and a ROM and RAM used as a main storage device. Each function of the path calculation unit 17 described below is realized, for example, by the processor 18 executing a computer program stored in the storage device 19.

[0016] Next, each function of the path calculation unit 17 will be described in detail. The route calculation unit 17 of the route search device 1 includes a driver search unit 20 , an allowable range estimation unit 21 , and a route search unit 22 . The route search unit 22 searches for a driving route Dr for the vehicle Ce from the current location (self-position) to the destination (S101 in FIG. 4). FIG. 4 is a flowchart showing the operation of the route search device 1. In searching for the driving route Dr, the route search unit 22 reads tolerance information from the personal DB 5. Next, as shown in FIG. 5, based on the tolerance range indicated by the read tolerance information, the route search unit 22 searches for the driving route Dr for the vehicle Ce so that road sections whose characteristic values ​​of stress factors are within the tolerance range (hereinafter also referred to as "allowable road sections R1") are given priority over road sections whose characteristic values ​​are outside the tolerance range (hereinafter also referred to as "unallowable road sections R2"). The classification of the allowable road sections R1 and the unallowable road sections R2 may be performed based on the classification results of the road sections stored in the personal DB 5 (S205 in FIG. 6), as will be described later. FIG. 5 illustrates an example in which the driving route Dr is searched for so that the vehicle Ce travels only on the allowable road sections R1. For example, if the stress factor is "narrow road" and the tolerance range is "road width of 3.5 m or more," road sections with a road width of 3.5 m or more will be within the tolerance range R1, and road sections with a road width of 3 m or less will be within the tolerance range R2. In particular, when searching for the driving route Dr, the route search unit 22 preferably searches for the driving route Dr of the vehicle Ce such that, among road sections whose characteristic values ​​of stress factors are within the allowable range (allowable road sections R1), road sections with higher stress levels are given priority. For example, if the stress factor is "narrow road" and the allowable range is "3.0 m," both road sections with road widths of 3 m and 3.5 m are within the allowable road sections R1, but the route search unit 22 searches for the driving route Dr such that road sections with a road width of 3.0 m (i.e., road sections with a narrower road width) are given priority.

[0017] Furthermore, when the route search unit 22 finishes searching for the travel route Dr, the driver search unit 20 causes the stress identification device 4 to start acquiring detection results (e.g., images of the surroundings of the vehicle Ce, distances and directions of surrounding objects) output from the surrounding environment sensor 2 and road section information obtained from the navigation device 7 (S102 in FIG. 4). Next, the driver search unit 20 causes the stress identification device 4 to start acquiring detection results (e.g., facial images of the target driver and biological information of the target driver) output from the driver sensor 3 (S103 in FIG. 4). Next, the driver search unit 20 causes the stress identification device 4 to start estimating, for each road section, the degree of stress S felt by the target driver while traveling on that road section, based on the acquired detection results, etc. (S104 in FIG. 4). Furthermore, when the stress identification device 4 finishes estimating the stress level S, the driver search unit 20 executes a data accumulation and analysis process (S105 in FIG. 4). In the data accumulation and analysis process, as shown in FIG. 6, the driver search unit 20 acquires information on the stress factor and the stress level S for each road section from the stress identification device 4 and stores the acquired information in the shared DB 6 (S201 in FIG. 6). FIG. 6 is a flowchart showing the processing contents of the data accumulation and analysis process. Next, the driver search unit 20 acquires characteristic values ​​of the acquired stress factors (S202 in FIG. 6). As the characteristic value, for example, a specific value such as road width or the distance in a characteristic section after projecting an image onto a characteristic section using DeepCluster can be used. For example, if the stress factor is "narrow road," the "road width" of the road section is acquired as the characteristic value from the map storage unit 16. Next, the driver search unit 20 executes a similar driver search process to search for drivers similar to the target driver (S203 in FIG. 6). In the similar driver search process, the tolerance range estimation unit 21 also estimates the tolerance range of the target driver for the characteristic value of the stress factor.

[0018] In the similar driver search process, the driver search unit 20 acquires similar driver information from the personal DB 5 (S301 in FIG. 7). FIG. 7 is a flowchart showing the processing contents of the similar driver search process. If there is no similar driver, the similar driver information stores information indicating that there is no similar driver. Next, the driver search unit 20 determines whether there is a driver similar to the target driver based on the acquired similar driver information (S302 in FIG. 7). If it is determined that there is no similar driver (S302 "No" in FIG. 7), the driver search unit 20 determines a driver similar to the target driver from among multiple drivers based on the data of multiple drivers stored in the shared DB 6 (see FIG. 2) (S303 in FIG. 7). Examples of the data of multiple drivers include a stress value for each driver regarding roads (in FIG. 2, the stress level S for multiple road widths), a stress value regarding objects, and driver characteristics.

[0019] As a method for determining a similar driver, for example, a method can be adopted in which the similarity between the degree of stress S felt by the target driver in response to a stress factor and the degree of stress S felt by a similar driver is calculated, and a driver whose way of feeling stress in response to a stress factor is similar to that of the target driver is searched for based on the calculated similarity. For example, the target driver is clustered into one of a plurality of clusters, and a driver belonging to the same cluster as the target driver is determined as a similar driver. As a clustering method, for example, DBSCAN can be adopted. The clustering result (information on which cluster the target driver belongs to) and information indicating a similar driver (similar driver information of the target driver) are stored in the personal DB5. Note that as another method for determining a similar driver, for example, a method can be adopted in which the similarity between the driver characteristics of the target driver, such as the DSQ (Driving Style Questionnaire), and the driving characteristics of a similar driver is calculated, and a similar driver similar to the target driver is searched for based on the calculated similarity. After determining a similar driver, the tolerance range estimation unit 21 calculates the tolerance threshold W of the target driver (hereinafter referred to as the "tolerance threshold W") TH Then, a threshold setting process is performed to set the threshold (also called "threshold value") (S304 in FIG. 7).

[0020] In the threshold setting process, the tolerance estimation unit 21 reads out stress data of the similar driver from the shared DB 6. Next, based on the read stress data, the tolerance range of the target driver for the characteristic value of the stress factor is estimated. As an example of a method for estimating the tolerance range, first, based on the stress data of the similar driver, a first stress estimation line L1 is generated, as shown in FIG. 8, which indicates the correspondence between the number of times (hereinafter also referred to as the "reference number of times of driving") that the similar driver has driven a first road section in which the characteristic value of the stress factor is a predetermined value, and the degree of stress S that the similar driver felt when driving that first road section. As the predetermined value, for example, the previous tolerance range threshold W stored in the personal DB 5 is used. TH , that is, the boundary value of the previous allowable range for the characteristic value can be used. Fig. 8 illustrates an example in which the stress factor is "narrow road", the characteristic value is "road width", the predetermined value is "3.5 m", and the first stress estimation line L1 is a straight line.

[0021] Next, the tolerance range estimation unit 21 generates a second stress estimation line L2 based on the stress data of the similar driver. The second stress estimation line L2 indicates the correspondence between the travel count parameter, which increases with an increase in the reference travel count, and the degree of stress S felt by the similar driver when the similar driver traveled a second road section in which the stress level was higher than that of the first road section until the travel count parameter changed to the next number. For example, if the characteristic value of the stress factor is "road width," the second road section is a road section narrower than the first road section. FIG. 8 illustrates an example in which the second road section is a "road section with a road width of 3 m" and the second stress estimation line L2 is a straight line. The first stress estimation line L1 and the second stress estimation line L2 may be generated in advance by the tolerance range estimation unit 21, stored in the shared DB 6, and read from the shared DB 6 when used.

[0022] Next, the tolerance estimation unit 21 determines whether the degree of stress S felt by the similar driver when traveling on the second road section is equal to or greater than the threshold value S based on the generated first stress estimation line L1 and second stress estimation line L2. TH The following threshold S is estimated as the number of trips parameter:TH For example, the degree of stress S that gives the driver a sense of anxiety can be used as the parameter. In FIG. 8, when the number of driving times parameter is "2", S≦S TH Next, the allowable range estimation unit 21 extracts the number of times the first road section has been driven that corresponds to the estimated number of times of driving parameter. In FIG. 8, the number of times the first road section has been driven that corresponds to the number of times of driving parameter "2" is "4". Next, the allowable range estimation unit 21 determines whether the number of times the target driver has driven the first road section (hereinafter also referred to as "actual number of times of driving") is equal to or greater than the extracted number of times of driving (hereinafter also referred to as "threshold number of times"). Then, if it is determined that the actual number of times of driving is less than the threshold number of times, the allowable range estimation unit 21 calculates the previous allowable range threshold W so that the allowable range is maintained. TH This tolerance threshold W TH In FIG. 8, when the actual number of driving times is less than 4, the allowable range threshold W TH On the other hand, when the allowable range estimation unit 21 determines that the actual travel count is equal to or greater than the threshold count, it determines that the characteristic value of the stress factor of the second road section is within the allowable range, and adjusts the current allowable range threshold W so that the characteristic value of the second road section is within the allowable range. TH In FIG. 8, when the actual number of driving times is 4 or more, the allowable range threshold W TH is set to 3m. The tolerance threshold W TH is stored in the personal DB5. TH When the setting is completed, the process proceeds to S204 in FIG.

[0023] On the other hand, when the driver search unit 20 determines that a driver similar to the target driver exists (S302 "Yes" in FIG. 7), the driver search unit 20 determines whether the target driver and the similar driver have become different in how they feel stress (S305 in FIG. 7). For example, if the target driver becomes accustomed to a stress factor that caused stress, and the target driver's stress level S for that stress factor becomes lower than the threshold value S TH Is it smaller than (S TH ) and S TH ​​If it is determined that the driver's perception of stress has changed, it is determined that the driver's perception of stress has changed. If it is determined that the driver's perception of stress has changed ("Yes" in S305 of FIG. 7), the driver search unit 20 determines a driver similar to the target driver from among the multiple drivers based on the data of the multiple drivers stored in the shared DB 6 (S303 of FIG. 7). Next, the allowable range estimation unit 21 executes a threshold setting process (S304 of FIG. 7) and proceeds to S204 of FIG. 6. On the other hand, if the driver search unit 20 determines that the subject driver and the similar driver do not feel different (are similar) in how they perceive stress ("No" in S305 of FIG. 7), the driver search unit 20 does not change the similar driver of the subject driver and maintains the similar driver (S306 of FIG. 7). Subsequently, the allowable range estimation unit 21 executes a threshold setting process (S304 of FIG. 7) and proceeds to S204 of FIG. 6.

[0024] Furthermore, when the similar driver search process is completed, the route search unit 22 calculates the set allowable range threshold W from the road sections of the road map data stored in the map storage unit 16. TH In particular, a road section having a road width equal to or greater than the allowable range threshold W is selected (S204 in FIG. 6). TH It is preferable to select a road section having a road width equal to or larger than the above and having similar characteristics to the road section for which stress data of a similar driver was obtained. Next, the route search unit 22 classifies the selected road section as an allowable road section R1 and classifies other road sections as unallowable road sections R2 so that the selected road section is used preferentially for the travel route Dr (S205 in FIG. 6). As a result, by using this classification result when searching for the next travel route Dr (i.e., the next time S101 in FIG. 4 is executed), the allowable range threshold W TH A travel route Dr can be searched for that gives priority to road sections having a road width of this size. The classification results of the allowable road sections R1 and the unallowable road sections R2 are stored in the personal DB 5. Once the classification of the road sections is complete, the process proceeds to S106 in FIG. 4.

[0025] Next, the route search unit 22 provides route guidance to the target driver so that the vehicle Ce travels along the travel route Dr set in S101 of FIG. 4 (S106 of FIG. 4). Route guidance to the target driver is provided using an output device such as a display or speaker (not shown). As a result, the target driver performs driving operations of the vehicle Ce so that the vehicle Ce travels along the travel route Dr. Next, the route search unit 22 determines whether the vehicle Ce has arrived at the destination (S107 of FIG. 4). If it is determined that the vehicle Ce has not arrived at the destination ("No" in S107 of FIG. 4), the route search unit 22 repeatedly executes the above flow from the detection of the surrounding environment (S102 of FIG. 4). If the vehicle Ce arrives at the destination while repeatedly executing the above flow, the route search unit 22 determines that the vehicle Ce has arrived at the destination ("Yes" in S107 of FIG. 4) and ends route guidance to the target driver.

[0026] (Effects of this embodiment) (1) Here, as a comparative example, for example, when the stress level S of the target driver is less than the threshold value S TH Consider a case where a configuration is configured to search for a driving route Dr of a vehicle Ce so as to avoid road sections where stress factors exceeding the threshold value S are present. In the configuration of this comparative example, for example, when a target driver drives a road section with a road width of 3 m and the stress level S is greater than or equal to the threshold value S, TH In this case, only a driving route Dr that does not include road sections with a road width of 3 m or less is proposed. Therefore, the stress level S for road sections with a road width of 3 m or less is not updated. For example, even if the target driver gains driving experience and the stress level S for road sections with a road width of 3 m or less decreases, road sections with a road width of 3 m or less will be permanently avoided. Therefore, for example, as shown in Figure 5, even if a driving route that also uses road sections with a road width of 3 m (unacceptable road section R2 in Figure 5) has a shorter route length than a driving route Dr that uses only road sections with a road width greater than 3 m (acceptable road section R1 in Figure 5), the driving route Dr that uses only road sections with a road width of 3 m (acceptable road section R1) will always be obtained as the search result, which may reduce road utilization efficiency.

[0027] In contrast to this, in this embodiment, the driver search unit 20 searches for a similar driver from among multiple drivers who feels stress in response to stress factors similar to that of the target driver, based on data on the multiple drivers. Next, the tolerance range estimation unit 21 estimates the target driver's tolerance range for the characteristic values ​​of stress factors based on stress data indicating the degree of stress S felt by the similar driver while traveling on road sections on which the searched similar driver has traveled in the past, for each characteristic value of the stress factors present in the road sections. Next, the route search unit 22 searches for a driving route Dr for the vehicle Ce based on the estimated tolerance range, such that road sections on which the characteristic values ​​of the stress factors are within the tolerance range are given priority over road sections on which the characteristic values ​​are outside the tolerance range. Here, for example, if the stress factor is "narrow road" and the characteristic value is "road width," and the target driver travels on a road section with a road width of 3.5 m, the degree of stress S will be greater than or equal to the threshold value S TH When driving on a road section with a width of 3 m, the degree of stress S is less than the threshold S TH Consider the above case. In this case, a search is made for similar drivers for whom a road section with a width of 3.5m is within their tolerance range, and based on the stress data of the similar drivers found, it is estimated that the target driver's tolerance range for narrow road widths is 3.5m or more. As a result, road sections with a road width of 3.5m or more are given priority when searching for a driving route Dr for vehicle Ce. This reduces the stress of the target driver.

[0028] Furthermore, for example, if the target driver gains driving experience on road sections with a road width of 3.5 m and the stress felt by the target driver when driving on road sections with a road width of 3.5 m decreases, a search is made for a similar driver with better driving skills. For example, a similar driver for whom road sections with a road width of 3 m are within the acceptable range is searched for. Then, based on the stress data of the searched similar driver, it is estimated that the target driver's tolerance range for narrow road widths is 3 m or more. As a result, road sections with a road width of 3 m or more are preferentially used to search for the driving route Dr of the vehicle Ce. Therefore, compared to searching for the driving route Dr of the vehicle Ce using only road sections with a road width of 3.5 m or more, the use of road sections that are more likely to cause stress can be promoted.

[0029] (2) The data for multiple drivers includes one or more of the following for each driver: stress levels for roads, stress levels for objects, and driver characteristics. This makes it possible to search for similar drivers who have similar stress levels for roads and objects to the target driver. (3) Furthermore, the tolerance range estimation unit 21 determines whether the degree of stress S felt by the similar driver when traveling on the second road section is equal to or greater than the threshold value S based on the first stress estimation line L1 and the second stress estimation line L2. TH The system estimates a travel count parameter such that: ##EQU1## and extracts the number of times the target driver has traveled the first road section corresponding to the estimated travel count parameter. If it is determined that the number of times the target driver has traveled the first road section is equal to or greater than the extracted number of times, it determines that the characteristic value of the stress factor in the second road section is within the acceptable range. In other words, if the number of times the target driver has traveled the first road section is equal to or greater than the number of times a similar driver traveled the first road section when the similar driver became accustomed to the second road section, it determines that the target driver has become accustomed to driving operations and the degree of stress S felt in the second road section has decreased. This makes it possible to suggest more stressful road sections to the target driver.

[0030] (Variation) (1) In the present embodiment, in the threshold setting process shown in S304 of FIG. 7, the acceptable range estimation unit 21 determines whether a second road section, in which stress is higher than that of the first road section, is within the acceptable range based on the number of times the first road section has been driven. However, other configurations may also be employed. For example, as shown in FIG. 9, a configuration may be adopted in which the acceptable range estimation unit 21 determines whether a second road section is within the acceptable range based on the degree of stress S felt by the target driver when driving the first road section. Specifically, in the threshold setting process (S304 of FIG. 7), the acceptable range estimation unit 21 first generates (acquires) a first stress estimation line L1 and a second stress estimation line L2 based on the stress data of the similar driver, using the same procedure as in the above embodiment. Next, as shown in FIG. 9, the acceptable range estimation unit 21 determines whether the degree of stress S felt by the similar driver when driving the second road section is within the acceptable range based on the generated (acquired) first stress estimation line L1 and second stress estimation line L2. TH Below (S≦STH ) is estimated. In FIG. 9, the first road section is a "road section with a road width of 3.5 m" and the second road section is a "road section with a road width of 3 m". In the example of FIG. 9, when the travel count parameter is "2", S≦S TH This becomes:

[0031] Next, the tolerance estimation unit 21 extracts the number of times the first road section has been traveled that corresponds to the estimated number of times traveled parameter, and extracts the degree of stress S that corresponds to the extracted number of times traveled. In FIG. 9, the number of times the first road section has been traveled that corresponds to the number of times traveled in the first road section that is "2" is "4", and the degree of stress S that corresponds to the number of times the first road section has been traveled "4" is "X TH ". Next, the acceptable range estimation unit 21 determines whether the level of stress S felt by the subject driver when traveling through the first road section (hereinafter also referred to as "actual stress level") is equal to or greater than the extracted level of stress S (hereinafter also referred to as "threshold stress"). If it is determined that the actual stress level is equal to or greater than the threshold stress, the acceptable range estimation unit 21 adjusts the previous acceptable range threshold W so that the acceptable range is maintained. TH This tolerance threshold W TH In Figure 9, the actual stress is set as X TH If it is greater than or equal to the tolerance threshold W TH On the other hand, when the allowable range estimation unit 21 determines that the actual stress level is less than the threshold stress, it determines that the characteristic value of the stress factor of the second road section is within the allowable range, and adjusts the current allowable range threshold W so that the characteristic value of the second road section is within the allowable range. TH In Figure 9, the actual stress is set to X TH If it is less than the tolerance threshold W TH is set to 3m. The tolerance threshold W TH is stored in the personal DB5. TH When the setting is completed, the process proceeds to S204 in FIG. That is, in this modified example, when the similar driver becomes accustomed to the second road section, the degree of stress S(X TH) is calculated. The stress level S of the target driver when driving the first road section is calculated as the stress level S(X TH ), it is determined that the target driver has become accustomed to driving operations and the degree of stress S felt in the second road section has decreased. This makes it possible to suggest more stressful road sections (i.e., road sections where the target driver is likely to feel stressed) to the target driver.

[0032] (2) In addition, in the present embodiment, an example has been shown in which the route calculation unit 17 mounted on the vehicle Ce implements the functions of the driver search unit 20, the acceptable range estimation unit 21, the route search unit 22, etc., but other configurations may also be adopted. For example, at least some of the above functions, the stress identification device 4, the personal DB 5, and the shared DB 6 may be implemented by a device outside the vehicle, such as a server device (not shown). In this case, the route calculation unit 17 and the device outside the vehicle constitute the route search device 1. [Explanation of symbols]

[0033] 1...Route search device, 2...Ambient environment sensor, 3...Driver sensor, 4...Stress identification device, 5...Personal DB, 6...Shared DB, 7...Navigation device, 8...External camera, 9...LiDAR, 10...Radar, 11...Driver camera, 12...Biometric sensor, 13...Stress estimation unit, 14...Factor identification unit, 15...Positioning unit, 16...Map memory unit, 17...Route calculation unit, 18...Processor, 19...Memory device, 20...Driver search unit, 21...Tolerance range estimation unit, 22...Route search unit

Claims

1. A route search device that searches for a vehicle's travel route, a driver search unit that searches for a similar driver from among the plurality of drivers based on data of the plurality of drivers, the similar driver having a similar way of feeling stress in response to stress factors to a target driver who is the driver of the vehicle; an allowable range estimation unit that estimates the allowable range of the target driver for the characteristic values ​​of the stress factors based on stress data that indicates the degree of stress felt by the similar driver while traveling on the road section for each characteristic value of the stress factors present in the road section that the searched similar driver has traveled in the past; and a route search unit that searches for a driving route for the vehicle based on the estimated allowable range so that road sections in which the characteristic values ​​of the stress factors are within the allowable range are given priority over road sections in which the characteristic values ​​are outside the allowable range. Route finding device.

2. The data of the plurality of drivers is at least one of a stress value for each driver with respect to the road, a stress value for each object, and a driver characteristic. The route search device according to claim 1 .

3. The tolerance estimation unit Based on the stress data of the similar driver, a first stress estimation line is generated which shows the correspondence between a reference number of travels, which is the number of times the similar driver traveled a first road section in which the characteristic value of the stress factor is a predetermined value, and the degree of stress felt by the similar driver when traveling the first road section, and a second stress estimation line which shows the correspondence between a travel number parameter which increases with an increase in the reference number of travels and the degree of stress felt by the similar driver when the similar driver traveled a second road section in which the stress level becomes higher than that of the first road section until the travel number parameter changes to the next number, Based on the generated first stress estimation line and the second stress estimation line, the travel count parameter at which the degree of stress felt by the similar driver when traveling on the second road section is equal to or less than a threshold is estimated, the number of travels on the first road section corresponding to the estimated travel count parameter is extracted, and if it is determined that the number of travels on the first road section by the target driver is equal to or greater than the extracted number of travels, it is determined that the characteristic value of the stress factor on the second road section is within the allowable range.

3. The route search device according to claim 1 or 2.

4. The tolerance estimation unit Based on the stress data of the similar driver, a first stress estimation line is generated which shows the correspondence between a reference number of travels, which is the number of times the similar driver traveled a first road section in which the characteristic value of the stress factor is a predetermined value, and the degree of stress felt by the similar driver when traveling the first road section, and a second stress estimation line which shows the correspondence between a travel number parameter which increases with an increase in the reference number of travels and the degree of stress felt by the similar driver when the similar driver traveled a second road section in which the stress level becomes higher than that of the first road section until the travel number parameter changes to the next number, Based on the generated first stress estimation line and second stress estimation line, the travel count parameter at which the degree of stress felt by the similar driver when traveling on the second road section is equal to or less than a threshold is estimated, a degree of stress according to the number of times the first road section is traveled corresponding to the estimated travel count parameter is extracted, and if it is determined that the degree of stress felt by the target driver when traveling on the first road section is smaller than the extracted degree of stress, it is determined that the characteristic value of the stress factor of the second road section is within the allowable range.

3. The route search device according to claim 1 or 2.

5. A route search method for searching a vehicle travel route, comprising: Based on data of a plurality of drivers, a search is made for a similar driver from among the plurality of drivers whose way of feeling stress in response to stress factors is similar to that of the target driver, who is the driver; based on stress data indicating the degree of stress felt by the similar driver while traveling on the road section for each characteristic value of the stress factor present in the road section traveled by the searched similar driver in the past, an estimate of the target driver's tolerance range for the characteristic value of the stress factor; Based on the estimated allowable range, a travel route of the vehicle is searched for such that road sections in which the characteristic values ​​of the stress factors are within the allowable range are given priority over road sections in which the characteristic values ​​are outside the allowable range. Route finding methods.

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