Route search device

Abstract

The present invention presents a driver with a route that provides the brain with stimulation for improving cognitive function and promoting brain development.　A route search device 1 comprises: a route search unit 112 that searches for a plurality of routes from the current location of a vehicle 10 to the destination thereof; a driving difficulty calculation unit 113 that calculates a driving difficulty on the basis of the travel environment of a route; an estimation unit 116 that estimates the driver's level of concentration on the basis of the recognition results of a first recognition unit 114, which recognizes the driver's facial expressions, and a second recognition unit 115, which recognizes the driver's biological information; a provisional total driving load value calculation unit 117 that calculates a provisional total driving load value, in a case where the destination is reached, on the basis of the driving difficulty and an arbitrarily determined degree of concentration; an actual driving load value calculation unit 118 that calculates an actual driving load value on the basis of the driver's level of concentration while traveling the route and the driving difficulty; and a control unit 119 that re-searches for a route on the basis of an estimated total driving load value at a destination arrival time calculated on the basis of the actual driving load value, and the estimated total driving load value.

Description

Route search device

[0001] The present invention relates to a route search device.

[0002] In recent years, vehicles have been equipped with navigation devices that provide driving guidance for the vehicle and enable the driver to easily reach a desired destination. For example, one such technology has been disclosed that, when searching for a route from a departure point to a destination, does not only search for an optimal route, but also searches for, for example, a recommended route, a route that prioritizes toll roads, a route that prioritizes general roads, a route that prioritizes distance, etc., and presents the route to the driver (see, for example, Patent Document 1).

[0003] Japanese Patent Application Laid-Open No. 2008-209208

[0004] However, with the above-mentioned technology, the driver is presented with an easy route or a route with the shortest driving distance each time, so even if the driver drives the route that has been searched for, brain activity is not stimulated, and the driver's cognitive function and brain development cannot be improved, which is a problem.

[0005] Therefore, the present invention has been made in consideration of the above-mentioned problems, and aims to provide a route search device that presents a driver with routes that stimulate the brain to improve cognitive function and promote brain development.

[0006] Mode 1: One or more embodiments of the present invention are a route search device that searches for a route to a destination specified by a driver, the route search device including: a route search unit that searches for a plurality of routes from a current location of a vehicle to the destination based on map data; a driving difficulty calculation unit that calculates a driving difficulty level based on a driving environment of the route; a first recognition unit that recognizes a facial expression of the driver; a second recognition unit that recognizes biometric information of the driver; an estimation unit that estimates a concentration level of the driver based on a recognition result of at least one of the first recognition unit and the second recognition unit; and a virtual total driving load calculation unit that calculates a virtual total driving load value when the destination is reached based on the driving difficulty level and the arbitrarily determined concentration level. a value calculation unit that calculates an actual driving load value based on the driver's concentration level and the driving difficulty level while traveling along the route; and a control unit that calculates an estimated total driving load value when the destination is reached based on the actual driving load value at each predetermined timing before arriving at the destination, and when it is determined that the estimated total driving load value will be lower than the tentative total driving load value, causes the route search unit to re-search the route so that the driving difficulty level of the route increases, and when it is determined that the estimated total driving load value will be higher than the tentative total driving load value, causes the route search unit to re-search the route so that the driving difficulty level of the route decreases.

[0007] Mode 2: One or more embodiments of the present invention are a route search device that searches for a route to a destination specified by a driver, the route search device including a controller and a biometric information detection device that detects biometric information of the driver, the controller including one or more processors and one or more memories communicably connected to the one or more processors, the one or more processors estimating a concentration level of the driver based on at least one or more pieces of information of the driver, either facial expression or biometric information, calculating a driving difficulty level based on a driving environment of the route, calculating an actual driving load value based on the concentration level and the driving difficulty level, and calculating an actual driving load value based on an arbitrarily determined driving difficulty level. The present invention proposes a route search device that calculates a tentative total driving load value when the destination is reached based on the concentration level, calculates an actual driving load value based on the driver's concentration level while traveling along the route and the driving difficulty level, calculates an estimated total driving load value when the destination is reached based on the actual driving load value at each predetermined timing before arriving at the destination, and if it is determined that the estimated total driving load value will be lower than the tentative total driving load value, re-searches for the route so that the driving difficulty of the route is increased, and if it is determined that the estimated total driving load value will be higher than the tentative total driving load value, re-searches for the route so that the driving difficulty of the route is decreased.

[0008] According to one or more embodiments of the present invention, it is possible to provide a driver with a route to stimulate the brain to improve cognitive function and promote brain development.

[0009] FIG. 1 is a diagram showing the configuration of a route search device according to an embodiment of the present invention. FIG. 2 is a diagram showing the configurations of a controller and a processor of the route search device according to an embodiment of the present invention. FIG. 3 is a diagram showing an example of a driving difficulty level calculated by a route search device according to an embodiment of the present invention. FIG. 4 is a diagram showing an example of a concentration level calculated by a route search device according to an embodiment of the present invention. FIG. 5 is a diagram showing an example of a provisional total driving load value calculated by a route search device according to an embodiment of the present invention. FIG. 6 is a diagram showing an example of a provisional total driving load value and an actual driving load value calculated by a route search device according to an embodiment of the present invention. FIG. 7 is a diagram showing the processing flow of a control unit of a route search device according to an embodiment of the present invention.

[0010] <Embodiment> A route search device 1 according to an embodiment of the present invention will be described with reference to Figs.

[0011] <Configuration of Route Search Device 1> As shown in Fig. 1, the route search device 1 according to this embodiment is mounted on a vehicle 10. In this embodiment, the route search device 1 is configured to include a controller 100 and a communication device 130. In this embodiment, the controller 100 is connected to a navigation device 20 and a camera 30 installed in the vehicle 10, and transmits and receives information. The controller 100 will be described later.

[0012] In this embodiment, the navigation device 20 is configured to include a display unit 21. In this embodiment, the display unit 21 is a display panel such as a liquid crystal panel or an organic EL panel, and displays a display screen for acquiring destination information from the driver of the vehicle 10, and information about the route from the current location to the destination selected by the driver, etc. In this embodiment, the navigation device 20 provides route guidance by displaying, for example, information about the route from the current location of the vehicle 10 to the destination on the display unit 21.

[0013] In this embodiment, the navigation device 20 displays information about a route searched for in either a route search mode, for example, the "standard mode" or the "brain activation mode," on the display unit 21. In this embodiment, when, for example, the "standard mode" is selected, the navigation device 20 executes a route search from the current location of the vehicle 10 to the destination. In this embodiment, when, for example, the "standard mode" is selected, the navigation device 20 searches for routes, such as a toll road priority route, a general road priority route, or a distance priority route, and provides guidance for the route selected by the driver. In this embodiment, when, for example, the "brain activation mode" is selected, the navigation device 20 causes the route search device 1 to execute a route search from the current location of the vehicle 10 to the destination. In this embodiment, when, for example, the "brain activation mode" is selected, the navigation device 20 prompts the driver to specify the brain load level when driving from the current location to the destination. The driver, for example, operates the navigation device 20 to specify the desired brain load level (for example, specify one of "high," "medium," or "low"). In this embodiment, for example, when the "brain activation mode" is selected, the navigation device 20 outputs destination information specified by the driver and information regarding the brain load level desired by the driver to the controller 100. In this embodiment, for example, when the "brain activation mode" is selected, the navigation device 20 displays information regarding the route acquired from the controller 100 (the route searched by the route search device 1) on the display unit 21, and performs guidance for the route selected by the driver. Details of the route acquired from the controller 100 will be described later. In this embodiment, for example, when the "brain activation mode" is selected, the navigation device 20 outputs information regarding the route selected by the driver to the controller 100.

[0014] In this embodiment, the camera 30 is, for example, a camera installed in the cabin of the vehicle 10, and captures an image of at least the driver of the vehicle 10. In this embodiment, the camera 30 outputs captured image information to the controller 100. For example, if a driver monitoring system is installed in the vehicle 10, the camera 30 may be a camera included in the driver monitoring system.

[0015] In this embodiment, the communication device 130 is, for example, a known wireless communication device and functions as an interface for communicating with a server 200 connected to a network N. An example of the network N is the Internet. In this embodiment, the server 200 stores, for example, information about traffic conditions for each road (e.g., traffic jam, congestion, smooth traffic, etc.). The information stored in the server 200 is updated as appropriate. In this embodiment, the communication device 130 is, for example, a short-range wireless communication device such as Bluetooth (registered trademark) and functions as an interface for communicating with a wearable device 300 worn by a driver. In this embodiment, the wearable device 300 acquires, for example, biometric information such as the driver's heart rate, respiratory rate, and blood pressure. In this embodiment, the wearable device 300 acquires, for example, average values ​​of biometric information (heart rate, respiratory rate, and blood pressure) during the period when the driver wears the wearable device 300. In this embodiment, when the wearable terminal 300 receives a request to send biometric information from the controller 100, for example, via the communication device 130, it transmits the average value of the driver's biometric information and the current biometric information of the driver to the controller 100.

[0016] <Configuration of Controller 100> The controller 100 is configured to include one or more processors and one or more memories communicably connected to the one or more processors. As shown in Fig. 2, in this embodiment, the controller 100 is configured to include a processor 110 and a memory 120. The configuration of the processor 110 will be described later.

[0017] The memory 120 includes a read-only memory (ROM), a random access memory (RAM), etc. (not shown). In this embodiment, the memory 120 stores, for example, a control program and various data input from the processor 110. In this embodiment, the memory 120 stores, for example, map data in advance.

[0018] 2, the processor 110 includes a location information acquisition unit 111, a route search unit 112, a driving difficulty calculation unit 113, a first recognition unit 114, a second recognition unit 115, an estimation unit 116, a provisional total driving load value calculation unit 117, an actual driving load value calculation unit 118, and a control unit 119. Each unit of the processor 110 and the memory 120 inputs and outputs various types of information via a bus line BL.

[0019] In this embodiment, the location information acquisition unit 111 acquires location information of the vehicle 10. In this embodiment, the location information acquisition unit 111 acquires the location information of the vehicle 10 based on, for example, radio waves received from a GPS (Global Positioning System) satellite. In this embodiment, when a location information acquisition request is input from a control unit 119 (described later) via, for example, the bus line BL, the location information acquisition unit 111 acquires the location information of the vehicle 10, for example, every second. In this embodiment, the location information acquisition unit 111 outputs the location information of the vehicle 10 to a route search unit 112 (described later) and the control unit 119 via, for example, the bus line BL.

[0020] The route search unit 112 searches for multiple routes from the current location of the vehicle 10 to the destination based on map data. In this embodiment, for example, when a "brain activation mode" is selected in the navigation device 20, the route search unit 112 searches for multiple routes from the current location to the destination that can activate the brain. In this embodiment, when destination information is input from the control unit 119 (described later) via the bus line BL, for example, the route search unit 112 searches for multiple routes from the current location to the destination based on the destination location information included in the destination information, the current location information acquired from the location information acquisition unit 111, and the map data stored in the memory 120. Examples of routes that can activate the brain include a route with many right and left turns to the destination, a route that requires driving on roads with heavy traffic, and a route that requires driving on narrow roads. In this embodiment, the route search unit 112 outputs information about the multiple routes it has searched to the control unit 119 (described later) via the bus line BL, for example.

[0021] In the present embodiment, when information about the route currently being guided and a request to re-search for a route are input from the control unit 119 (described later) via the bus line BL, for example, the route search unit 112 re-searches for a route from the current position of the vehicle 10 to the destination. In the present embodiment, when information about the route currently being guided and a request to re-search for a route with a higher driving difficulty level are input from the control unit 119 (described later) via the bus line BL, for example, the route search unit 112 re-searches for a route with a higher driving difficulty level than the route currently being guided by the navigation device 20, and outputs information about the re-searched route to the control unit 119 (described later). In the present embodiment, when information about the route currently being guided and a request to re-search for a route with a lower driving difficulty level are input from the control unit 119 (described later) via the bus line BL, for example, the route search unit 112 re-searches for a route with a lower driving difficulty level than the route currently being guided by the navigation device 20, and outputs information about the re-searched route to the control unit 119 (described later). In this embodiment, the driving difficulty level of the above-mentioned route is determined, for example, by the road shape of the route, traffic conditions, and the number of right and left turns made when traveling along the route. In this embodiment, for example, the wider the road width of the route to be traveled, the lower the driving difficulty level. In this embodiment, for example, the lower the traffic volume of the route to be traveled, the lower the driving difficulty level. In this embodiment, for example, the fewer the number of right and left turns made when traveling from the current location to the destination, the lower the driving difficulty level.

[0022] The driving difficulty calculation unit 113 calculates the driving difficulty based on the driving environment of the route. In this embodiment, when the driving difficulty calculation unit 113 receives information about the route currently being guided from the control unit 119 (described later) via the bus line BL, the driving difficulty calculation unit 113 calculates the driving difficulty based on the driving environment of the route. The driving difficulty calculation unit 113 calculates the driving difficulty based on one or more of the traffic conditions of the route currently being guided, the road shape, and the number of right and left turns made while traveling along the route. An example of a method for calculating the driving difficulty based on the traffic conditions of the route, the road shape, and the number of right and left turns made while traveling along the route will be described with reference to FIG. 3 . In this embodiment, when the driving difficulty calculation unit 113 receives information about the route currently being guided from the control unit 119 (described later) via the bus line BL, the driving difficulty calculation unit 113 receives information about the traffic conditions of the route (e.g., smooth traffic, congestion, traffic jam, etc.) from the server 200 via the communication device 130. In this embodiment, the driving difficulty calculation unit 113 determines whether the acquired route includes a location where congestion / congestion has occurred, for example, based on information about the traffic conditions of the route acquired from the server 200 (Determination Result 1). In this embodiment, when the driving difficulty calculation unit 113 acquires information about the currently navigating route from the control unit 119 (described later) via the bus line BL, the driving difficulty calculation unit 113 determines, for example, whether the acquired route includes a narrow road where passing is impossible, based on the map data stored in the memory 120 (Determination Result 2). In this embodiment, when the driving difficulty calculation unit 113 acquires information about the currently navigating route from the control unit 119 (described later) via the bus line BL, the driving difficulty calculation unit 113 acquires the number of right and left turns made while traveling along the acquired route based on the map data stored in the memory 120, and determines whether the number of right and left turns is, for example, 30 or more (Determination Result 3). In this embodiment, the driving difficulty calculation unit 113 quantifies Determination Results 1, 2, and 3 based on, for example, the conversion table shown in FIG. 3, and multiplies the respective values ​​to obtain a driving difficulty level. The driving difficulty calculation unit 113 is not limited to the calculation method described above, as long as it can quantify the driving difficulty of the route currently being guided by the navigation device 20 .The driving difficulty calculation unit 113 may further check, for example, whether the route includes a mountain pass with a series of curves, and calculate the driving difficulty level. In this embodiment, the driving difficulty calculation unit 113 outputs information about the calculated driving difficulty level to a provisional total driving load value calculation unit 117, an actual driving load value calculation unit 118, and a control unit 119, which will be described later, via the bus line BL.

[0023] The first recognition unit 114 recognizes the driver's facial expression. In this embodiment, when a recognition request is input from the control unit 119 (described later) via the bus line BL, the first recognition unit 114 analyzes image information acquired from the camera 30 and detects, for example, the driver's eye opening degree and blink frequency (e.g., the number of blinks per minute). In this embodiment, the first recognition unit 114 stores in the memory 120 information on the driver's eye opening degree and blink frequency that is first detected when the recognition request is input from the control unit 119 (described later). In other words, the first recognition unit 114 stores in the memory 120 information on the driver's eye opening degree and blink frequency when the driver starts driving. In this embodiment, when a recognition request is input from the control unit 119 (described later) via the bus line BL, the first recognition unit 114 continuously detects the driver's eye opening degree and blink frequency, and outputs the detected information on the driver's eye opening degree and blink frequency (hereinafter referred to as facial expression information) to the estimation unit 116 (described later).

[0024] The second recognition unit 115 recognizes the driver's biometric information. The second recognition unit 115 recognizes one or more of the biometric information, namely, heart rate, respiratory rate, and blood pressure. In this embodiment, when a recognition request is input from the control unit 119 (described later) via the bus line BL, the second recognition unit 115 transmits a request to transmit the biometric information to the wearable terminal 300 via the communication device 130. In this embodiment, the second recognition unit 115 outputs, for example, via the bus line BL, the average value of the driver's biometric information (heart rate, respiratory rate, blood pressure) acquired from the wearable terminal 300 and the current driver's biometric information (heart rate, respiratory rate, blood pressure) to the estimation unit 116 (described later).

[0025] The estimation unit 116 estimates the concentration level of the driver based on the recognition result of at least one of the first recognition unit 114 and the second recognition unit 115. In this embodiment, when an estimation request is input from the control unit 119 (described later) via the bus line BL, the estimation unit 116 estimates the concentration level of the driver based on the recognition result acquired from the first recognition unit 114 and the biometric information of the driver acquired from the second recognition unit 115.

[0026] An example of a method for calculating the concentration level based on the recognition results of the first recognition unit 114 and the second recognition unit 115 will be described with reference to FIG. 4 . In this embodiment, when an estimation request is input from the control unit 119 (described later) via the bus line BL, the estimation unit 116 determines whether the current eye opening value of the driver acquired from the first recognition unit 114 is greater than the eye opening value of the driver stored in the memory 120. In this embodiment, when an estimation request is input from the control unit 119 (described later) via the bus line BL, the estimation unit 116 determines whether the current blink count of the driver acquired from the first recognition unit 114 is greater than the blink count of the driver stored in the memory 120. In other words, the estimation unit 116 determines how the current eye opening value and blink count of the driver have changed relative to the eye opening value and blink count at the start of driving. As shown in FIG. 4 , in this embodiment, the estimation unit 116 determines whether at least one of the current eye opening value and blink count of the driver is greater than the value stored in the memory 120 (determination result 4).

[0027] In this embodiment, when an estimation request is input from the control unit 119 (described later) via the bus line BL, for example, the estimation unit 116 determines whether the driver's current heart rate acquired from the second recognition unit 115 is 10% or more higher than the average driver heart rate. In this embodiment, when an estimation request is input from the control unit 119 (described later) via the bus line BL, for example, the estimation unit 116 determines whether the driver's current respiratory rate acquired from the second recognition unit 115 is 10% or more higher than the average driver respiratory rate. In this embodiment, when an estimation request is input from the control unit 119 (described later) via the bus line BL, for example, the estimation unit 116 determines whether the driver's current blood pressure acquired from the second recognition unit 115 is 10% or more higher than the average driver blood pressure. As shown in FIG. 4 , in this embodiment, the estimation unit 116 determines whether at least one of the driver's heart rate, respiratory rate, and blood pressure is 10% or more higher than the average (determination result 5). In this embodiment, the estimation unit 116 digitizes the determination results 4 and 5 based on, for example, the conversion table shown in Fig. 4 and obtains a numerical value obtained by multiplying the respective numerical values ​​as the driver's concentration level. In this embodiment, the estimation unit 116 outputs information related to the calculated driver's concentration level to a provisional total driving load value calculation unit 117 and an actual driving load value calculation unit 118 (described later) via, for example, the bus line BL. Note that the estimation unit 116 is not limited to the above-mentioned method as long as it can digitize the driver's concentration level based on the driver's facial expression and the driver's biological information.

[0028] The provisional total driving load value calculation unit 117 calculates a provisional total driving load value when the destination is reached based on the driving difficulty level and an arbitrarily determined concentration level. The provisional total driving load value calculation unit 117 calculates a provisional total driving load value when the destination is reached based on the driving difficulty level of the route currently being guided and the concentration level determined based on an instruction from the driver. In this embodiment, the provisional total driving load value calculation unit 117 calculates the provisional total driving load value based on, for example, the driving difficulty level of the route currently being guided calculated by the driving difficulty calculation unit 113 and the brain load level set by the driver (the brain load levels "high," "medium," or "low" set by the driver when setting the destination). In this embodiment, the provisional total driving load value calculation unit 117 calculates the provisional total driving load value when, for example, a calculation request and information on the brain load level set by the driver are input from the control unit 119 (described later) via the bus line BL. An example of a method for calculating the provisional total driving load value will be described with reference to FIG. 5 . In the present embodiment, the provisional total driving load value calculation unit 117 calculates a provisional total driving load value by multiplying the driving difficulty level obtained from the driving difficulty level calculation unit 113 by the concentration level determined based on the brain load level set by the driver. In the present embodiment, for example, if the brain load level set by the driver is "high," the provisional total driving load value calculation unit 117 sets the concentration level to 4 and calculates the provisional total driving load value. In the present embodiment, for example, if the brain load level set by the driver is "medium," the provisional total driving load value calculation unit 117 sets the concentration level to 2 and calculates the provisional total driving load value. In the present embodiment, for example, if the brain load level set by the driver is "low," the provisional total driving load value calculation unit 117 sets the concentration level to 1 and calculates the provisional total driving load value. In this embodiment, the tentative total operating load value calculation unit 117 outputs the calculation result to the control unit 119 (described later) via, for example, the bus line BL.

[0029] The actual driving load value calculation unit 118 calculates an actual driving load value based on the driver's concentration level while driving the route and the driving difficulty level. In other words, the actual driving load value calculation unit 118 quantifies the actual load on the driver's brain based on the driver's concentration level while driving the route and the driving difficulty level of the route currently being guided. In this embodiment, when an actual driving load value calculation request is input from the control unit 119 (described later) via the bus line BL, the actual driving load value calculation unit 118 calculates an actual driving load value based on the concentration level acquired from the estimating unit 116 and the driving difficulty level acquired from the driving difficulty calculation unit 113. In this embodiment, the actual driving load value calculation unit 118 calculates, for example, a value obtained by multiplying the concentration level value acquired from the estimating unit 116 by the driving difficulty level value acquired from the driving difficulty calculation unit 113, as the actual driving load value. In this embodiment, the actual driving load value calculation unit 118 outputs the calculated actual driving load value to a control unit 119 (described later) via, for example, the bus line BL. Note that the actual driving load value calculation unit 118 is not limited to the calculation method described above, as it is sufficient if it can quantify the magnitude of the load on the driver's brain based on the driver's concentration level while driving and the driving difficulty level of the route.

[0030] In this embodiment, the control unit 119 controls the entire route search device 1 in accordance with a control program stored in the memory 120. In this embodiment, for example, when destination information is input from the navigation device 20, the control unit 119 outputs the destination information to the route search unit 112 via the bus line BL. In this embodiment, for example, when destination information is input from the navigation device 20, the control unit 119 outputs a recognition request to the first recognition unit 114 and the second recognition unit 115 via the bus line BL. In this embodiment, for example, when the control unit 119 acquires information about a searched route from the route search unit 112, the control unit 119 outputs the information about the searched route to the navigation device 20. In this embodiment, for example, when the control unit 119 acquires information about a route selected by the driver from the navigation device 20, the control unit 119 outputs information about the route currently being guided (information about the route selected by the driver) to the driving difficulty calculation unit 113 via the bus line BL. In this embodiment, for example, when the control unit 119 acquires information regarding driving difficulty from the driving difficulty calculation unit 113, it outputs a calculation request and information regarding the load level on the brain set by the driver to the provisional total driving load value calculation unit 117 via the bus line BL.

[0031] The control unit 119 calculates an estimated total driving load value at the time of arrival at the destination based on the actual driving load value calculated by the actual driving load value calculation unit 118 at each predetermined timing before arrival at the destination. In other words, the control unit 119 quantifies the magnitude of the load on the driver's brain when driving the route being guided to the destination based on the actual concentration level of the driver estimated from the driver's biometric information and facial expression information and the driving difficulty level of the route being guided. In this embodiment, the control unit 119 calculates the estimated total driving load value at each predetermined timing before arrival at the destination, for example.

[0032] An example of the predetermined timing and a method for calculating the estimated total driving load value will be described with reference to FIG. 6 . In this embodiment, the control unit 119 divides, for example, a travel distance (e.g., 20 km) of a route from a departure point to a destination into four equal parts and sets checkpoints (e.g., checkpoints CP1, CP2, and CP3) on the route. In this embodiment, when the control unit 119 determines that the vehicle 10 has reached each checkpoint based on, for example, the location information of the vehicle 10 acquired from the location information acquisition unit 111, the control unit 119 outputs an estimation request to the estimation unit 116 and outputs an actual driving load value calculation request to the actual driving load value calculation unit 118. In this embodiment, the control unit 119 acquires, for example, an actual driving load value from the actual driving load value calculation unit 118 each time the vehicle 10 reaches a checkpoint. In this embodiment, the control unit 119 calculates the estimated total driving load value based on, for example, the actual driving load value acquired from the actual driving load value calculation unit 118. As shown in Fig. 6, in this embodiment, for example, if the actual driving load value acquired when the vehicle 10 reaches checkpoint CP1, which is set by equally dividing the distance traveled on the route from the departure point to the destination, is α, the control unit 119 calculates the estimated total driving load value as (4 x α) / 4. In this embodiment, for example, if the actual driving load value acquired when the vehicle 10 reaches checkpoint CP2, which is set by equally dividing the distance traveled on the route from the departure point to the destination, is β, the control unit 119 calculates the estimated total driving load value as (α + 3 x β) / 4. In this embodiment, for example, if the actual driving load value acquired when the vehicle 10 reaches checkpoint CP3, which is set by equally dividing the distance traveled on the route from the departure point to the destination, is γ, the control unit 119 calculates the estimated total driving load value as (α + β + 2 x γ) / 4.

[0033] When the control unit 119 determines that the estimated total driving load value is lower than the tentative total driving load value, the control unit 119 causes the route searching unit 112 to re-search for a route so that the driving difficulty of the route is increased. When the control unit 119 determines that the estimated total driving load value is higher than the tentative total driving load value, the control unit 119 causes the route searching unit 112 to re-search for a route so that the driving difficulty of the route is decreased. In this embodiment, for example, the control unit 119 compares the tentative total driving load value with the estimated total driving load value calculated at each checkpoint. In this embodiment, for example, when the control unit 119 determines that the tentative total driving load value is lower than the estimated total driving load value calculated at each checkpoint, the control unit 119 outputs information about the route currently being guided and a route search request with an increased driving difficulty to the route searching unit 112 via the bus line BL. In the present embodiment, for example, when the control unit 119 determines that the provisional total driving load value is higher than the estimated total driving load value calculated at the checkpoint, the control unit 119 outputs information about the route currently being guided and a request for route search with a lower driving difficulty level to the route search unit 112 via the bus line BL. In the present embodiment, for example, when the control unit 119 determines that the provisional total driving load value is lower than the estimated total driving load value calculated at the checkpoint, the control unit 119 outputs information about the route re-searched by the route search unit 112 and a suggested comment for the driver to the navigation device 20. In the present embodiment, for example, when the control unit 119 determines that the provisional total driving load value is lower than the estimated total driving load value calculated at the checkpoint, the control unit 119 displays a comment such as, for example, "If you continue driving the route being guided to your destination, it is unlikely that you will reach the brain load level you set. We will suggest a route that will further activate your brain. Please touch the screen to check the details of the proposed route," on the display unit 21 of the navigation device 20, and urges the driver to travel the re-searched route. In this embodiment, when the control unit 119 determines that the provisional total driving load value is higher than the estimated total driving load value calculated at the checkpoint, for example, it may display a message such as, "If you continue driving to your destination on the route being guided, it is likely that you will exceed the brain load level that you set. We will suggest a route that reduces the brain load. Please touch the screen to check the details of the suggested route."" is displayed on the display unit 21 of the navigation device 20, urging the driver to travel along the route that has been re-searched. In this embodiment, when the driver selects a new route proposed by the route search device 1, the navigation device 20 starts route guidance based on the new route.

[0034] <Processing Flow of Control Unit 119> The processing flow of the control unit 119 will be described with reference to FIGS. 7 and 8. FIG.

[0035] The control unit 119 determines whether or not destination information has been acquired from the navigation device 20 (step S110). If the control unit 119 determines that destination information has not been acquired from the navigation device 20 ("NO" in step S110), the control unit 119 returns the process to a standby state. If the control unit 119 determines that destination information has been acquired from the navigation device 20 ("YES" in step S110), the control unit 119 transitions the process to step S120.

[0036] The control unit 119 causes the route search unit 112 to search for a plurality of routes to the destination, outputs information about the searched routes to the navigation device 20 (step S120), and moves the process to step S130.

[0037] The control unit 119 determines whether information about the route selected by the driver has been acquired from the navigation device 20 (step S130). If the control unit 119 determines that information about the route selected by the driver has not been acquired from the navigation device 20 ("NO" in step S130), the control unit 119 returns the process to a standby state. If the control unit 119 determines that information about the route selected by the driver has been acquired from the navigation device 20 ("YES" in step S130), the control unit 119 transitions the process to step S140.

[0038] The control unit 119 causes the driving difficulty level calculation unit 113 to calculate the driving difficulty level of the route selected by the driver (step S140), and then causes the process to proceed to step S150.

[0039] The control unit 119 causes the first recognition unit 114 to start acquiring facial expression information of the driver (step S150), and then causes the process to proceed to step S160.

[0040] The control unit 119 causes the second recognition unit 115 to start acquiring biometric information of the driver (step S160), and then causes the process to proceed to step S170.

[0041] The control unit 119 causes the provisional total driving load value calculation unit 117 to calculate a provisional total driving load value (Y) based on the driving difficulty calculated in step S140 and the brain load level set by the driver (step S170), and then causes the process to proceed to step S180 shown in Figure 8.

[0042] The control unit 119 determines whether the vehicle 10 has reached a checkpoint set on the route being guided, based on the position information of the vehicle 10 acquired from the position information acquisition unit 111 (step S180). When the control unit 119 determines, based on the position information of the vehicle 10 acquired from the position information acquisition unit 111, that the vehicle 10 has not reached a checkpoint set on the route being guided ("NO" in step S180), the control unit 119 returns the process to standby. When the control unit 119 determines, based on the position information of the vehicle 10 acquired from the position information acquisition unit 111, that the vehicle 10 has reached a checkpoint set on the route being guided ("YES" in step S180), the control unit 119 transitions the process to step S190.

[0043] The control unit 119 causes the estimation unit 116 to calculate the driver's concentration level based on the driver's facial expression information and biometric information acquired from the first recognition unit 114 and the second recognition unit 115 (step S190), and then transitions the processing to step S200.

[0044] The control unit 119 causes the actual driving load value calculation unit 118 to calculate the actual driving load value based on the driving difficulty calculated in step S140 and the driver's concentration level obtained in step S190 (step S200), and then transitions the processing to step S210.

[0045] The control unit 119 calculates an estimated total operating load value (X) based on the actual operating load value calculated in step S200 (step S210), and then proceeds to step S220.

[0046] The control unit 119 compares the provisional total driving load value (Y) calculated in step S170 with the estimated total driving load value (X) calculated in step S210 (step S220). If the control unit 119 determines that the provisional total driving load value (Y) is greater than the estimated total driving load value (X) ("Y>X" in step S220), it outputs a request to the route search unit 112 to re-search for a route with an increased driving difficulty level (step S230), and proceeds to step S250. If the control unit 119 determines that the provisional total driving load value (Y) is less than the estimated total driving load value (X) ("Y<X" in step S220), it outputs a request to the route search unit 112 to re-search for a route with a decreased driving difficulty level (step S240), and proceeds to step S250. When the control unit 119 determines that the tentative total operating load value (Y) is the same as the estimated total operating load value (X) ("Y=X" in step S220), it ends the process.

[0047] The control unit 119 outputs information about the route searched for by the route search unit 112, comments, etc. to the navigation device 20 (step S250), and ends the process.

[0048] <Actions and Effects> As described above, the route search device 1 according to this embodiment includes a route search unit 112 that searches for a plurality of routes from the current location of the vehicle 10 to the destination based on map data, a driving difficulty calculation unit 113 that calculates a driving difficulty level based on the driving environment of the route, a first recognition unit 114 that recognizes the facial expression of the driver, a second recognition unit 115 that recognizes biometric information of the driver, an estimation unit 116 that estimates a concentration level of the driver based on recognition results of at least one of the first recognition unit 114 and the second recognition unit 115, and a provisional total driving load value calculation unit 117 that calculates a provisional total driving load value when the destination is reached based on the driving difficulty level and an arbitrarily determined concentration level. and a control unit 119 that calculates an estimated total driving load value at the time of arrival at the destination based on the actual driving load value calculated by the actual driving load value calculation unit 118 at each predetermined timing before arrival at the destination, and causes the route search unit 112 to re-search for a route so that the driving difficulty of the route increases when it is determined that the estimated total driving load value will be lower than the provisional total driving load value, and causes the route search unit 112 to re-search for a route so that the driving difficulty of the route decreases when it is determined that the estimated total driving load value will be higher than the provisional total driving load value. The route search device 1 calculates the load on the driver's brain when traveling the route to the destination (estimated total driving load value) based on the actual load on the driver's brain (actual driving load value) at a predetermined timing before arrival at the destination. If the route search device 1 determines that the assumed brain load (provisional total driving load value) will be exceeded if the driver drives the current route to the destination, it presents the driver with a route with a lowered driving difficulty level. If the route search device 1 determines that the assumed brain load value will not be reached if the driver drives the current route to the destination, it presents the driver with a route with a higher driving difficulty level. In this way, the route search device 1 can present the driver with a route that takes into account the magnitude of the driver's brain load. The route search device 1 can present the driver with a route that provides stimulation to the brain to improve cognitive function and promote brain development.

[0049] The provisional total driving load value calculation unit 117 of the route search device 1 according to this embodiment calculates a provisional total driving load value when the driver reaches the destination based on the driving difficulty level and the concentration level determined based on instructions from the driver. The route search device 1 calculates the brain load (provisional total driving load value) when traveling along the route to the destination based on the driving difficulty level of the searched route and the brain load level (e.g., "high," "medium," or "low") set by the driver. The route search device 1 checks, at a predetermined timing before arriving at the destination, whether the estimated total driving load value will exceed the provisional total driving load value if the driver drives the route to the destination at his / her current concentration level. In other words, if the route search device 1 determines that the brain load level set by the driver will be exceeded if the driver drives the current route to the destination at his / her current concentration level, it suggests a route with a lower driving difficulty level to the driver. If the route search device 1 determines that the brain load level set by the driver will be exceeded if the driver drives the route to the destination at his / her current concentration level, it displays a comment such as, for example, "If you continue driving the route being guided to the destination, it is likely that you will exceed the brain load level you set. We will suggest a route that reduces the brain load. Please touch the screen to check the details of the proposed route," on the navigation device 20, and urges the driver to travel the route that has been re-searched. If the route search device 1 determines that the brain load level set by the driver will not be reached if the driver drives the route to the destination at his / her current concentration level, it suggests a route with a higher driving difficulty to the driver. If the route search device 1 determines that the brain stress level set by the driver will not be reached if the driver drives the current route to the destination, it displays a comment on the navigation device 20, such as, "If you continue driving the route being guided to your destination, it is unlikely that you will reach the brain stress level you set. We will suggest a route that will further activate your brain. Please touch the screen to check the details of the proposed route," and urges the driver to drive the route that has been re-searched.As a result, the driver can train the desired amount of brain function by driving the route to the destination, as the route search device 1 suggests a route that matches the set brain load level. The route search device 1 can present the driver with a route that stimulates the brain to improve cognitive function and promote brain development.

[0050] The second recognition unit 115 of the route search device 1 according to this embodiment recognizes one or more of the biological information, namely, heart rate, respiratory rate, and blood pressure. The fluctuation value of the biological information while driving differs for each driver. Therefore, the brain load of the driver is estimated based on the difference between the driver's normal biological information and the biological information while driving. This makes it possible to estimate the brain load of the driver who drives the vehicle 10 with high accuracy.

[0051] The first recognition unit 114 of the route search device 1 according to this embodiment recognizes facial expression information such as the degree of eye opening and the number of blinks of the driver. The fluctuation value of facial expression information (e.g., the degree of eye opening and the number of blinks of the driver) while driving varies from driver to driver. Therefore, the route search device 1 estimates the load on the driver's brain based on the difference between the facial expression information acquired when the driver started driving and the driver's current facial expression information. This allows the route search device 1 to estimate the load on the driver's brain while driving the vehicle 10 with high accuracy.

[0052] The driving difficulty calculation unit 113 of the route search device 1 according to this embodiment calculates the driving difficulty level based on one or more of the road shape of the route, the traffic conditions, and the number of right and left turns made when traveling along the route. In other words, the driving difficulty calculation unit 113 evaluates the route to be traveled from multiple perspectives and calculates the driving difficulty level of the route. This allows the route search device 1 to calculate with high accuracy the load on the brain when driving along the route.

[0053] <Modification 1> The program for the processing of the route search device 1 described above may be executed in a processor and memory provided in the navigation device 20.

[0054] <Modification 2> The route search device 1 described above determines the predetermined timing based on the travel distance of the vehicle 10. However, for example, the actual driving load value calculation unit 118 may calculate the actual driving load value every hour, and calculate the estimated total driving load value.

[0055] <Modification 3> The provisional total driving load value calculation unit 117 of the above-described route search device 1 may perform a correction to lower the calculated provisional total driving load value when the weather is, for example, rainy or snowy. For example, when the route search device 1 determines that the weather around the vehicle 10 is rainy or snowy based on image information from a camera capturing an image of the area around the vehicle 10, the provisional total driving load value may be set to, for example, 50% of the provisional total driving load value calculated by the provisional total driving load value calculation unit 117. In other words, the route search device 1 is more likely to present routes with low driving difficulty, which can prevent excessive strain on the driver's brain. This allows the driver to drive with peace of mind.

[0056] <Variation 4> The route search device 1 may acquire from the driver, for example, information regarding sections of the route from the current location to the destination where the driver desires to place a strain on the brain and information regarding sections where the driver desires not to place a strain on the brain. For example, the driver may set a section where the driver desires to travel on an expressway or the like rather than a narrow road with many turns, and a section where the driver desires to travel on a road with many turns. This allows the driver to train their brain function in the desired section.

[0057] <Variation 5> The route search device 1 described above communicates with the wearable device 300 worn by the driver to acquire biometric information such as the driver's heart rate, respiratory rate, and blood pressure, but the biometric information may also be acquired from a biometric sensor installed on the steering wheel or seat of the vehicle 10. The second recognition unit 115 of the route search device 1 acquires the biometric information from the biometric sensor, for example, without going through the communication device 130. This makes it possible to acquire the driver's biometric information even when the driver is not wearing the wearable device 300.

[0058] <Modification 6> The route search device 1 described above does not re-search for a route when the estimated total driving load value and the tentative total driving load value are the same value. However, for example, if the difference between the estimated total driving load value and the tentative total driving load value is smaller than a predetermined value (for example, 20% of the tentative total driving load value), the route search device 1 may not re-search for a route. This can reduce the frequency of route changes.

[0059] The route search device 1 of the present invention can be realized by recording the processes of the above-mentioned route search unit 112, driving difficulty calculation unit 113, first recognition unit 114, second recognition unit 115, estimation unit 116, provisional total driving load value calculation unit 117, actual driving load value calculation unit 118, and control unit 119 on a recording medium readable by a computer system, and loading and executing the program recorded on this recording medium into memory. The computer system here includes hardware such as an OS and peripheral devices.

[0060] The above computer system also includes a homepage providing environment (or display environment) if it utilizes a WWW (World Wide Web) system. The above program may be transmitted from a computer system storing the program in a storage device or the like to another computer system via a transmission medium or by transmission waves in the transmission medium. The transmission medium for transmitting the above program refers to a medium having the function of transmitting information, such as a network (communication network) such as the Internet or a communication line (communication line) such as a telephone line.

[0061] The above program may be for realizing some of the above functions, or may be a so-called differential file (differential program) that can realize the above functions in combination with a program already recorded in the computer system.

[0062] Although embodiments of the present invention have been described above in detail with reference to the drawings, all route search devices that can be implemented by a person skilled in the art through appropriate design modifications based on the above-described route search device as an embodiment of the present invention also fall within the scope of the present invention as long as they incorporate the gist of the present invention. Within the scope of the concept of the present invention, a person skilled in the art may conceive of various modifications and alterations, and it is understood that these modifications and alterations also fall within the scope of the present invention. For example, devices in which a person skilled in the art appropriately adds, deletes, or modifies components of the above-described embodiments, or adds, omits, or modifies processes, also fall within the scope of the present invention as long as they incorporate the gist of the present invention.

[0063] Furthermore, other effects brought about by the aspects described in the present embodiment that are apparent from the description in this specification or that can be appropriately conceived by a person skilled in the art are naturally understood to be brought about by the present invention. Various inventions can be formed by appropriately combining multiple components disclosed in the above embodiments. For example, some components may be deleted from all of the components shown in the embodiments. Furthermore, components across different embodiments may be appropriately combined.

[0064] 1; Route search device 10; Vehicle 20; Navigation device 30; Camera 100; Controller 110; Processor 111; Position information acquisition unit 112; Route search unit 113; Driving difficulty calculation unit 114; First recognition unit 115; Second recognition unit 116; Estimation unit 117; Provisional total driving load value calculation unit 118; Actual driving load value calculation unit 119; Control unit 120; Memory 130; Communication device 200; Server 300; Wearable terminal N; Network

Claims

1. A route search device that searches for a route to a destination specified by a driver, comprising: a route search unit that searches for a plurality of routes from the current location of a vehicle to the destination based on map data; a driving difficulty calculation unit that calculates a driving difficulty level based on the driving environment of the route; a first recognition unit that recognizes the facial expression of the driver; a second recognition unit that recognizes the biometric information of the driver; an estimation unit that estimates the driver's concentration level based on the recognition results of at least one of the first recognition unit and the second recognition unit; a provisional total driving load value calculation unit that calculates a provisional total driving load value when the destination is reached based on the driving difficulty level and the arbitrarily determined concentration level; an actual driving load value calculation unit that calculates an actual driving load value based on the driver's concentration level and the driving difficulty level while traveling along the route; and an estimated total driving load value when the destination is reached based on the actual driving load value at each predetermined timing before arriving at the destination. a control unit that, when it is determined that the estimated total driving load value is lower than the tentative total driving load value, causes the route searching unit to re-search the route so that the driving difficulty of the route is increased, and when it is determined that the estimated total driving load value is higher than the tentative total driving load value, causes the control unit to re-search the route so that the driving difficulty of the route is decreased.

2. The route search device described in claim 1, characterized in that the provisional total driving load value calculation unit calculates the provisional total driving load value when the destination is reached based on the driving difficulty level and the concentration level determined based on instructions from the driver.

3. The route search device described in claim 1 or 2, characterized in that the driving difficulty calculation unit calculates the driving difficulty based on one or more of the traffic conditions on the route, the road shape of the route, and the number of right and left turns when traveling along the route.

4. The route search unit according to claim 3, characterized in that the second recognition unit recognizes one or more of the biological information of heart rate, respiratory rate, and blood pressure.

5. A route search device that searches for a route to a destination specified by a driver, comprising: a controller; and a biometric information detection device that detects biometric information of the driver, wherein the controller includes one or more processors and one or more memories communicably connected to the one or more processors, wherein the one or more processors: estimate the driver's concentration level based on at least one of facial expression and biometric information of the driver; calculate a driving difficulty level based on the driving environment of the route; calculate an actual driving load value based on the concentration level and the driving difficulty level; calculate a provisional total driving load value when the destination is reached based on the driving difficulty level and the arbitrarily determined concentration level; calculate an actual driving load value based on the driver's concentration level and the driving difficulty level while traveling on the route; and calculate an estimated total driving load value when the destination is reached based on the actual driving load value at each predetermined timing before arriving at the destination. When it is determined that the estimated total driving load value will be lower than the tentative total driving load value, the route search device re-searches for the route so that the driving difficulty of the route increases, and when it is determined that the estimated total driving load value will be higher than the tentative total driving load value, the route search device re-searches for the route so that the driving difficulty of the route decreases.

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