Driving assistance device, driving assistance method, driving assistance program, and storage medium

Abstract

The present invention includes: a map database in which map data is stored; a vibration penalty database that manages, in association with each link of a road based on the map data, a vibration index expression or an actual vibration index expression corresponding to the magnitude of vibration applied to a moving body traveling on the link; a vibration penalty value acquisition unit that acquires, from the map database, vibration penalty values which are each calculated by the vibration index expression or the actual vibration index expression stored, by the vibration penalty database, in the map database as a vibration penalty index expression for calculating a vibration penalty value, and which correspond to links included in map information of a designated map area designated by a user; and a display control unit that, while displaying a map of the designated map area on a display, displays information representing the level of vibration, based on each of the acquired vibration penalty values, on the map being displayed so as to be visually associable with each of the links.

Description

Driving assistance device, driving assistance method, driving assistance program and storage medium

[0001] The present invention relates to a driving assistance device, and particularly to a driving assistance device, a driving assistance method, a driving assistance program, and a storage medium that provide driving assistance performed based on the behavior of a moving body.

[0002] A navigation device, which serves as a driving assistance device mounted on a moving body such as a vehicle, has a driving assistance function of searching for a route from a current point to a destination according to the designation of the destination, and guiding the searched route through display, voice, or other means.

[0003] Conventionally, route search is performed by giving priority to efficiency such as travel distance to the destination, required time, or energy consumption. Therefore, there has been a risk that a route with poor riding comfort may be searched.

[0004] Accordingly, a navigation device that performs route evaluation and route selection giving priority to riding comfort has been proposed (see Patent Document 1). In the route selection mode of this navigation device, for each of a plurality of route candidates searched in advance, a weighted sum of acceleration detection times calculated from the road shape indicated by road information corresponding to the route candidate is calculated as a comprehensive evaluation value representing the riding comfort of the vehicle. Then, the plurality of route candidates are compared with each other to select a route to be guided.

[0005] Japanese Unexamined Patent Application Publication No. 2017-20859

[0006] By the way, when driving a vehicle, the navigation device described in Patent Document 1 searches for a route in advance, so the route does not always provide the optimal riding comfort in some cases. In addition, when searching for a route, there was no room for the user to select between a route with small vehicle vibration and a route with a preferred magnitude of vehicle vibration. There was also the problem that it was not possible to provide a service that evaluated vehicle vibration not only based on riding comfort, or performed route search that mixed route evaluation based on factors other than vibration.

[0007] One of the objectives of the present invention is to provide a driver assistance device, a driver assistance method, a driver assistance program, and a storage medium that enable more optimal route searching in relation to shaking and that increase the degree of freedom of the user in route searching in relation to shaking.

[0008] The invention described in claim 1 comprises: a map database storing map data; a vibration penalty database that manages vibration index formulas or actual vibration index formulas corresponding to the magnitude of vibrations experienced by a moving body traveling along a road link based on the map data; a vibration penalty value acquisition unit that acquires vibration penalty values ​​from the map database, corresponding to each of the links included in the map information of a designated map area specified by the user, using vibration penalty index formulas or actual vibration index formulas stored in the map database to calculate vibration penalty values; and a display control unit that displays a map of the designated map area on a display and displays information representing the level of vibration based on each of the acquired vibration penalty values ​​on the displayed map in a way that allows visual association with each of the links.

[0009] The invention described in claim 9 involves a shake penalty database that stores shake index formulas or actual shake index formulas corresponding to the magnitude of shaking experienced by a moving object traveling along a road, associated with each road link based on map data stored in a map database. The shake penalty value is calculated using one of the shake index formulas or actual shake index formulas for each link stored in the map database as a shake penalty index formula for each link, and the shake penalty value is obtained from the shake index formula or actual shake index formula for each link, which is associated with the map information of a specified map area designated by the user. The map of the specified map area is displayed on the display, and information representing the level of shaking based on each of the obtained shake penalty values ​​is displayed on the displayed map in a way that allows it to be visually associated with each of the links.

[0010] The invention described in claim 10 is a program to be executed by a computer, comprising the steps of: obtaining a vibration penalty value calculated using a vibration index formula or actual vibration index formula corresponding to each of the links included in the map information of a designated map area specified by the user, from among the vibration index formulas or actual vibration index formulas for each link stored in the map database as vibration penalty index formulas for each link, which are associated with each road link based on map data stored in the map database and correspond to the magnitude of vibration acting on a moving body traveling along that link; and displaying the map of the designated map area on a display, and displaying on the displayed map information information representing the level of vibration based on each of the acquired vibration penalty values ​​so as to be visually associated with each of the links.

[0011] The invention described in claim 11 is a storage medium in which the program described in claim 10 is stored.

[0012] This is a diagram showing the configuration of the driver assistance system 100. This is a diagram showing an example of the contents stored in the sway penalty database 52. This is a diagram showing an example of the contents stored in the map database 51. This is a block diagram showing the configuration of the driver assistance device 10. This is a flowchart showing the procedure of the route search instruction routine. This is a flowchart showing the procedure of the route search routine. This is a flowchart showing the configuration of the driver assistance system 100A, showing the procedure of the sway level display routine. This is a flowchart showing the procedure of the route search instruction routine executed by the driver assistance system 100A. This is a diagram showing an example of the display of the sway level display map in display mode A. This is a diagram showing another example of the display of the sway level display map in display mode A. This is a diagram showing an example of the display of the sway level display map in display mode B. This is a diagram showing an example of the display of the sway level display map in display mode C. This is a diagram showing an example of the display of the sway level display map when the scale of the display map is increased.

[0013] Preferred embodiments of the present invention are described in detail below.

[0014] Figure 1 shows the configuration of the driver assistance system 100.

[0015] The driver assistance system 100 includes a driver assistance device 10 mounted on a vehicle VH as a mobile unit, and an information collection server 40, a server 50, and a driver assistance computer 60 connected to the Internet NW.

[0016] The driver assistance system 10 displays a map with a marker indicating the current position of the vehicle VH superimposed on the map, and also has a navigation function that guides the driver to a specified destination. The driver assistance system 10 also has the following route search modes for searching the above-mentioned route: normal mode, comfort mode, and sport driving mode. In normal mode, the route to the destination is searched with priority given to driving distance, travel time, or energy saving. In comfort mode, the route to the destination is searched with priority given to routes that minimize the shaking experienced by the vehicle's occupants. In sport driving mode, the route to the destination is searched with priority given to routes suitable for sport driving, such as routes with many curves that cause significant shaking.

[0017] Furthermore, the driver assistance system 10 is equipped with a vibration level display function that displays a map showing the level of vibration acting on the vehicle's VH during driving.

[0018] The information collection server 40 is a server managed by an organization that manages probe data, and has a driving database that stores the actual driving data as said probe data. The information collection server 40 collects actual driving data from multiple vehicles driving on the road, for example via the Internet NW, and stores it in the driving database, and also provides the actual driving data stored in the driving database to users. The actual driving data is, for example, location information, average speed and average acceleration (vertical, horizontal, and longitudinal directions), and driving history, linked to each road section for each time period when multiple vehicles are actually driving on the road.

[0019] Server 50 has various databases, including a map database 51 and a vibration penalty database (hereinafter also referred to as the vibration penalty DB) 52. Server 50 reads and stores desired information from the database specified in a request in response to a request received via the Internet NW. Furthermore, Server 50 includes a route search unit 53 that searches for a route from the starting point to the destination according to the route search mode described above.

[0020] The map database 51 stores various information about the Earth's surface, including the locations of all roads, rivers, railways, administrative divisions, and shops, as well as other locations included in maps of the entire country. The map database 51 also stores general penalty values ​​used for route searching in normal mode.

[0021] Incidentally, the vibration penalty DB52 stores a vibration index formula fn(n, v) which is associated with each road link or node shown in the map data and calculates a vibration penalty value corresponding to the magnitude of vibrations experienced by the vehicle in the longitudinal, lateral, or vertical directions when traveling along that link or node.

[0022] In the oscillation index formula fn(n,v), "n" is an identification number representing a link or node, and "v" is the travel speed.

[0023] In other words, the sway index formula fn(n,v) first calculates the lateral acceleration of the vehicle (v^2 / R) using the radius of curvature R at one link (node) or multiple connected links (nodes) determined from the road shape based on map data, and the driving speed v, as a sway index value representing the magnitude of lateral sway. Furthermore, for example, the sway index formula fn(n,v) calculates the longitudinal acceleration of the vehicle using the driving speed v immediately before entering one link (node) or multiple connected links (nodes) and the driving speed v within the link after a predetermined time has elapsed from immediately before entry, as a sway index value representing the magnitude of longitudinal sway. Then, the sway index formula fn(n,v) calculates the final sway penalty value by normalizing the above sway index values.

[0024] Furthermore, for links and nodes that include stopping and deceleration sections such as intersections, railway crossings, or pedestrian crossings where vehicles may stop, the sway index formula fn(n, v) is as follows:

[0025] In other words, the sway index formula fn(n, v) calculates the sway penalty value by normalizing the acceleration calculated based on the time or distance over which the vehicle decelerates from its speed v immediately before entering such a stopping and deceleration zone, and the speed difference between that time or distance and the vehicle's speed v immediately after deceleration.

[0026] Furthermore, for links and nodes where the stopping and deceleration section includes an intersection, the sway index formula fn(n, v) calculates a predetermined sway penalty value corresponding to the lateral sway of the vehicle, and a sway penalty value corresponding to the longitudinal sway of the vehicle, as described below. In other words, the sway index formula fn(n, v) calculates the sway penalty value corresponding to the longitudinal sway of the vehicle by normalizing the acceleration calculated based on the time length or distance over which the vehicle decelerates from its current speed v immediately before entering the stopping and deceleration section including the intersection, and the speed difference between this time length or distance and the vehicle's current speed v immediately after deceleration.

[0027] Here, the estimated driving speed v is used as the estimated driving speed for each time period, which is estimated based on the average driving speed at the link (node) obtained from traffic information, for example. In other words, the driving speed of a vehicle changes depending on the time of day, but the average driving speed of the vehicle at that time period can be obtained from traffic information. Therefore, fn(n, v, t*) may be adopted, which adds a parameter t* representing the time period to the oscillation index formula.

[0028] As shown in Figure 2A, the vibration penalty DB 52 stores a vibration index formula fn(n, v, t*) for each link (node).

[0029] Furthermore, the sway penalty value may be a normalized actual sway index value, which represents the magnitude of sway calculated based on actual driving data collected from multiple vehicles that traveled through that link (node) for each time period, and is calculated based on the actual sway index formula gn(n, t*). Here, as mentioned above, the actual driving data is probe data held by the information collection server 40, and includes information indicating the acceleration in the longitudinal direction, lateral direction, and vertical direction of the vehicle. Therefore, gn(n, t*) is calculated by obtaining actual sway index values ​​that represent the magnitude of sway in the longitudinal, lateral, and vertical directions of the vehicle from the acceleration in each of these directions, and normalizing these actual sway index values ​​to calculate the sway penalty value.

[0030] As shown in Figure 2A, the vibration penalty database manages the vibration index formula fn(n, v, t*) and the actual vibration index formula gn(n, t*) stored for each road link (node) as follows: First, the vibration index formula is stored in the map database 51. Then, when the actual driving data, which is probe data held by the information collection server 40, has accumulated sufficiently, the actual vibration index formula is stored in the map database 51. Furthermore, when changes such as road shape or the creation of new intersections appear in the map database 51 due to road construction, the vibration index formula fn(n, v, t*) in the vibration penalty database 52 is updated, and this update is also reflected in the vibration index formula stored in the map database 51. Similarly, when the actual driving data in the actual driving database is updated, gn(n, t*) in the vibration penalty database 52 is updated, and this update is also reflected in the actual vibration index formula stored in the map database 51. The timing of the update of gn(n, t*) may be when a predetermined number of actual driving data have been updated, or it may be at a predetermined time on a predetermined day of the week as separately defined.

[0031] As a result, the map database 51 stores one of the actual seismic index formulas gn(n, t*) and fn(n, v, t*), associated with each road link (node), as shown in Figure 2B, for example.

[0032] Furthermore, in addition to the actual vibration index formula gn(n, t*) and vibration index formula fn(n, v, t*), the map database 51 stores general penalty values ​​associated with each road link (node), as shown in Figure 2B. These include, for example, general penalty value 1 related to fuel consumption or general penalty value 2 related to travel time.

[0033] The map database on server 50 receives the link ID n and time zone t* in response to a request for obtaining a tremor penalty value from the section route search unit, calculates the tremor penalty value based on the stored tremor index formula or actual tremor index formula, and sends it to the requesting section route search unit.

[0034] The driver assistance computer 60 stores at least the software that controls the vibration level display function, which is installed in the driver assistance device 10, and is capable of displaying a map representing the vibration level, similar to the driver assistance device 10.

[0035] Figure 3 is a block diagram showing the internal configuration of the driver assistance device 10.

[0036] As shown in Figure 3, the driving assistance device 10 includes a communication unit 11, an input unit 12, an acceleration sensor 13, a map data acquisition unit 14, a position detection unit 15, a display unit 16, an audio output unit 17, a driving speed sensor 18, and a control unit 20.

[0037] The communication unit 11, in response to a request from the control unit 20, transmits and receives various information data to and from the server 50 via wireless communication over the Internet network (NW).

[0038] The input unit 12 includes, for example, an operation remote control, a switch located on the screen of the display unit 16, or an operation switch such as a touch panel attached to the screen that accepts user input. The input unit 12 supplies operation signals to the control unit 20 that represent the instruction content (described later) indicated by the user's input.

[0039] The acceleration sensor 13 detects acceleration acting on the vehicle VH in the longitudinal, lateral, and vertical directions. The acceleration sensor 13 may also detect jerk. The acceleration sensor 13 supplies acceleration signals to the control unit 20, individually indicating the detected acceleration acting on the vehicle VH in the longitudinal, lateral, and vertical directions.

[0040] The map data acquisition unit 14 includes a storage device in which map data is stored, and reads map information for a specified area from the storage device and supplies it to the control unit 20. The storage device is, for example, a magnetic disk drive, semiconductor memory, CD (Compact Disc), or DVD (Digital Versatile Disc). Alternatively, the map data acquisition unit 14 may acquire map data from the map database 51 contained in the server 50 via wireless communication through the communication unit 11.

[0041] The position detection unit 15 includes, for example, a GPS (Global Positioning System) receiver and analyzes GPS radio waves received from GPS satellites to acquire current position information indicating the current position (latitude and longitude) of the vehicle VH, and supplies it to the control unit 20. The position detection unit 15 may also have a function to estimate the current position of the vehicle VH by autonomous navigation using an acceleration sensor and an angular velocity sensor, etc.

[0042] The display unit 16 includes a display panel (display) such as a liquid crystal or organic EL, and displays images of operation switches for the touch panel or a map image in which a mark indicating the current location is superimposed on a map of the area around the vehicle VH's current location, according to display instructions from the control unit 20. The audio output unit 17 includes a speaker and outputs audio from the speaker according to audio instructions from the control unit 20.

[0043] The driving speed sensor 18 detects the current actual driving speed of the vehicle VH and supplies an actual driving speed signal indicating that actual driving speed to the control unit 20.

[0044] The control unit 20 includes a non-volatile memory 21 and a RAM (Random Access Memory) 22. In addition to the non-volatile memory 21 and the RAM 22, the control unit 20 may be a microcomputer including a CPU (Central Processing Unit) that executes programs and an arithmetic circuit.

[0045] The non-volatile memory 21 stores a driving support program that includes a vibration level display routine as a program for controlling a vibration level display function, in addition to a current position display routine, a route search instruction routine, a route guidance routine, etc., which are programs for controlling a navigation function. The non-volatile memory 21 may be a semiconductor memory such as a PROM (Programmable read only memory), an SSD (solid state drive), or a flash memory, or may be a magnetic disk or an optical disk. Furthermore, the driving support program may be provided from outside the vehicle VH via an information communication network such as the Internet NW. In this case, the device providing the driving support program is provided with a PROM, SSD, flash memory, magnetic disk, optical disk or the like storing the driving support program.

[0046] First, the control unit 20 executes a current position display routine stored in the non-volatile memory 21. In accordance with the current position display routine, the control unit 20 first acquires, from the map data acquisition unit 14, map information of a surrounding area including the position indicated by the current position information supplied from the position detection unit 15. Next, the control unit 20 causes the display unit 16 to display a map image in which a current position mark of the vehicle is superimposed on the position indicated by the aforementioned current position information on the map, together with the map of the surrounding area.

[0047] Here, when the user issues a route search instruction by operating the input unit 12 to cause the device to perform a route search, the control unit 20 proceeds to execution of the route search instruction routine.

[0048] FIG. 4A is a flowchart showing an outline procedure of the route search instruction routine.

[0049] In Figure 4A, the control unit 20 first receives input from the user regarding the departure point, departure time, destination, and route search mode (normal mode, comfort mode, or sport driving mode) (step S30).

[0050] Next, the control unit 20 confirms the information entered by the user, including the departure point, departure time, destination, and route search mode (step S31).

[0051] Next, the control unit 20 causes the communication unit 11 to send a route search request signal containing the confirmed information to the server 50 (step S32).

[0052] After step S32 is executed, the control unit 20 receives the route search result transmitted by the server 50 in response to the route search request signal via the communication unit 11 (step S33).

[0053] Figure 4B is a flowchart illustrating the general procedure of the route search routine that the server 50 instructs the route search unit 53 to execute when it receives a route search request signal.

[0054] In Figure 4B, the route search unit 53 first receives information indicating the departure point, departure time, destination, and route search mode, which is included in the route search request signal transmitted from the vehicle VH's driver assistance device 10 (step S40).

[0055] Next, the route search unit 53 obtains map information for the map area including the departure point and destination, and all vibration penalty values ​​from the map database 51, and stores them in its built-in RAM (step S41).

[0056] Next, the route search unit 53 determines whether the route search mode described above is the normal mode (step S42).

[0057] If it is determined in step S42 that it is in normal mode, the route search unit 53 proceeds to execute the normal route search routine (step S43).

[0058] In this standard route search routine, the route search unit 53 first obtains general penalty values ​​related to travel time and fuel consumption for each of the multiple links and nodes stored in the map database 51, based on the map information obtained in step S41. Next, the route search unit 53, for example, following Dijkstra's algorithm, selects the link with the smallest general penalty value from among the multiple links connected to each node in the multiple routes connecting the origin and destination, and selects the route connecting the origin and destination with the selected links as the guided route.

[0059] Therefore, if the route search mode specified by the user is normal mode, the route selected as the guided route from the current location to the destination will be one that minimizes factors such as travel time and fuel consumption.

[0060] On the other hand, if it is determined in step S42 that the mode is not normal, the route search unit 53 determines whether the route search mode is the comfort mode (step S44). If it is determined in step S44 that the mode is the comfort mode, the route search unit 53 proceeds to execute the comfort route search routine (step S45).

[0061] In this comfortable route search routine, the route search unit 53 first obtains general penalty values ​​and sway penalty values ​​related to travel time and fuel consumption for each of the multiple links connected from the starting point to the destination, which are stored in the map database 51, based on the map information obtained in step S41. Next, the route search unit 53 selects a guided route as follows, for example, according to Dijkstra's algorithm.

[0062] In other words, the route search unit 53 calculates, for each node included in the multiple routes connecting the origin and destination, that it weights and adds up the general penalty value and the vibration penalty value corresponding to each link from among the one or more links connected to that node. At this time, the route search unit 53 selects the link that minimizes the weighted sum from among the multiple links connected to each node, and selects the route connecting the origin and destination with the selected link as the guided route. The route search unit 53 may also be configured to allow adjustment of the weights used when weighting up the general penalty value and the vibration penalty value.

[0063] Furthermore, if in step S44 the route search mode is determined not to be the comfort mode, the route search unit 53 proceeds to execute the sports driving route search routine (step S46).

[0064] In the sports driving route search routine, the route search unit 53 sets a predetermined sway penalty value for sports driving. Next, the route search unit 53, for example, following Dijkstra's algorithm, selects a link from among the one or more links connected to each node in a route connecting the starting point and the destination, such that the weighted sum of the sway penalty value set according to the magnitude of the error with the predetermined sway penalty value and the general penalty value is minimized. Then, the route search unit 53 selects the route connecting the selected links between the starting point and the destination as the guided route. The user may also be allowed to increase or decrease the predetermined sway penalty value for sports driving based on the results of the previous sports driving mode.

[0065] After step S43, S45, or S46 is executed, the server 50 transmits a route search result signal indicating the guided route found by the route search unit 53 to the driver assistance device 10 of the requesting vehicle VH (step S47).

[0066] When the communication unit 11 of the driver assistance device 10 receives such a route search result signal, it supplies information indicating the guided route shown in the route search result signal to the control unit 20. As a result, the control unit 20 executes a route guidance routine, causing the display unit 16 and the audio output unit 17 to process the vehicle VH along the guided route using voice and display.

[0067] Furthermore, in addition to the aforementioned normal mode, comfort mode, and sport driving mode, the route search mode may also offer a user-customized mode. In user-customized mode, settings such as weighting combinations that minimize shaking, customizations that include many values ​​within a predetermined range of shaking penalty values, and customizations that completely exclude large shaking penalty values ​​corresponding to strong shaking may be pre-configured and available for the user to select and input. Moreover, the weighting itself may be customizable by the user.

[0068] Thus, in the driver assistance system 10, when the user specifies normal mode, the server 50 searches for a route from the vehicle VH's starting point to its destination, and the server 50 provides a guided route that prioritizes factors such as travel time and fuel efficiency.

[0069] Furthermore, if the user selects the comfort mode, the server 50 will provide a guided route that reduces the shaking on the vehicle's VH while also minimizing travel time and fuel consumption.

[0070] Furthermore, when the user selects a sports driving mode, the server 50 provides a guided route that minimizes the desired level of vibration on the vehicle's VH (vehicle vibration control) while also reducing travel time and fuel consumption. For example, the server 50 may provide a guided route that includes frequent curves or a route that prioritizes only lateral vibration without considering longitudinal acceleration.

[0071] Therefore, the driver assistance device 10 and server 50 enable route searching that prioritizes driving distance, travel time, or energy saving (normal mode), as well as route searching that suppresses vibrations on the vehicle's VH (comfort mode) and route searching that applies vibrations of a desired magnitude to the vehicle's VH (sports driving mode).

[0072] In the above embodiment, the route search instruction process and route search process for finding a route from the starting point to the destination are performed by software as shown in Figures 4A and 4B, but this may also be implemented in hardware.

[0073] In short, the driver assistance system should include the following: a section route search unit, a map database containing map data, and a vibration penalty database.

[0074] In other words, the vibration penalty database (52) associates each road link based on map data with a vibration index formula or actual vibration index formula corresponding to the magnitude of vibration experienced by a moving object traveling on that link.

[0075] The section route search unit (20, 50-53, S30-S33, S40-S47) receives a designation of the departure point and destination and searches for a guidance route to guide the moving object from the designated departure point to the destination based on map data as follows. Specifically, the section route search unit obtains a shake penalty value from the shake penalty database (52) that has been calculated using the shake index formula fn(n, v, t*) or the actual shake index formula gn(n, t*) stored in the map database (51) as a shake penalty index formula for calculating the shake penalty value, and uses the obtained shake penalty value to search for a guidance route based on map data.

[0076] By the way, in the driving support system 100 shown in Figure 1, the map database 51, the vibration penalty database 52, and the route search unit 53 are provided on the server 50, but these map database 51, vibration penalty database 52, and route search unit 53 may also be provided within the driving support device 10 mounted on the vehicle VH.

[0077] Figure 6 shows the configuration of a driver assistance system 100A, which is another example of a driver assistance system 100, made in view of the above points.

[0078] The driver assistance system 100A is identical to that shown in Figure 1, except that it uses an update management server 500 instead of server 50 and a driver assistance device 10A instead of driver assistance device 10 as a driver assistance device to be installed in vehicle VH.

[0079] Furthermore, the driver assistance device 10A is identical to the driver assistance device 10 in all other respects, except that it includes the map database 51, the vibration penalty database 52, and the route search unit 53 shown in Figure 1.

[0080] However, in the driver assistance device 10A, when the control unit 20 receives a route search instruction from the user, it executes the route search routine shown in Figure 7 instead of the route search instruction routine shown in Figure 4A.

[0081] In the route search routine shown in Figure 7, the control unit 20 of the driving support device 10A first executes steps S30 and S31 in order, similar to the route search instruction routine shown in Figure 4A. After executing step S31, the control unit 20 executes steps S41 to S46 of the route search routine shown in Figure 4B.

[0082] As a result, when the user selects normal mode, the driver assistance system 10A searches for a guided route that prioritizes travel time, fuel efficiency, etc. (S43). When the user selects comfort mode, the driver assistance system 10A searches for a guided route that suppresses the shaking on the vehicle VH while also minimizing travel time and fuel efficiency, etc. (S45). When the user selects sport driving mode, the driver assistance system 10A searches for a guided route that achieves the desired level of shaking on the vehicle VH while also minimizing travel time and fuel efficiency, etc. (S46).

[0083] Therefore, with the driver assistance device 10A, in addition to route searching that prioritizes driving distance, required time, or energy saving (normal mode), it is possible to perform route searching that suppresses vibrations on the vehicle's VH (comfort mode) and route searching that applies vibrations of a desired magnitude to the vehicle's VH (sports driving mode).

[0084] The update management server 500 includes a map database 501, a vibration penalty database 502, and a route search unit 503. The map database 501, vibration penalty database 502, and route search unit 503 each have the same functions as the aforementioned map database 51, vibration penalty database 52, and route search unit 53. However, the contents of the map database 501 and vibration penalty database 502 are constantly updated with the latest map data. As a result, the update management server 500 updates the contents of the map database 51, vibration penalty database 52, and route search unit 53 included in the driver assistance device 10A installed in the vehicle VH via the Internet network (NW).

[0085] In the embodiment described above, the server 50 and the update management server 500 are located on the Internet network, but this is not limited to that. For example, these servers (50, 500) may be distributed on the cloud, on the vehicle H, or on other networks, or they may be installed on a specific terminal. Similarly, the route search unit may be located on the server 50, on the vehicle, distributed on other networks, or installed on a specific terminal.

[0086] Incidentally, the driver assistance device 10 is equipped with a vibration level display function that displays a vibration level, which represents the magnitude of vibrations acting on the vehicle, on a display map within a map area specified by the user (referred to as the specified map area). In this case, the vibration level display function is activated in response to a vibration level display command from the user using the input unit 12.

[0087] The tremor level display command includes information specifying the departure point, destination, and planned travel time, as well as information specifying one of the following display modes A to C. [Display Mode A] Characters (numbers) representing the tremor level are displayed near each corresponding link (node). [Display Mode B] The tremor level is divided into multiple ranks, and the links (nodes) corresponding to each rank are displayed in a different color for each rank. [Display Mode C] Links (nodes) corresponding to tremor levels above a predetermined value that are subject to warning are displayed in a predetermined color (e.g., red) to indicate warning, and links (nodes) corresponding to tremor levels below the predetermined value are displayed in the same color other than the predetermined color.

[0088] Figure 5 is a flowchart showing the procedure of the shaking level display routine that the control unit 20 executes in response to the shaking level display command described above.

[0089] In Figure 5, the control unit 20 first acquires map information for a designated map area specified by the user from the map data acquisition unit 14 (step S200).

[0090] Next, the control unit 20 causes the communication unit 11 to send a request to the server 50 for obtaining a vibration penalty value, which includes the scheduled travel time specified by the user and information indicating all links (nodes) within the specified map area (step S201).

[0091] In this case, the server 50, upon receiving the request to acquire the vibration penalty value, calculates a vibration penalty value from the map database 51 for each link (node) indicated in the vibration penalty value acquisition request, corresponding to the time period estimated from the scheduled travel time. The server 50 then transmits the vibration penalty value corresponding to each link (node) to the driver assistance device 10 of the requesting vehicle VH via the Internet NW.

[0092] Here, when the control unit 20 receives multiple vibration penalty values ​​transmitted from the server 50 via the communication unit 11, it associates each of them with the corresponding link (node) and stores them in the RAM 22 (step S202).

[0093] Next, the control unit 20 determines which of the above-described display modes A to C the shaking level display command indicates (step S203).

[0094] In step S202, if it is determined that display mode A is specified, the control unit 20 causes the display unit 16 to display a map in which characters (numbers) representing the vibration penalty value corresponding to each link or node are displayed as vibration levels near each link or node included in the specified map area (step S204). As a result, for example as shown in Figure 8A, the display unit 16 displays a map in which characters (numbers) representing the vibration penalty value corresponding to each link are displayed near each link in the specified map area, which includes multiple road links shown by solid lines and multiple nodes shown by white circles, as vibration levels.

[0095] Furthermore, the control unit 20 may set a threshold to distinguish whether the tremor penalty value is large enough to warrant caution or attention, and display characters representing tremor penalty values ​​exceeding this threshold as tremor levels, and characters representing tremor penalty values ​​below the threshold as tremor levels, using different colors, font sizes, and character fonts. For example, if the control unit 20 sets the threshold to "10", as shown in Figure 8B, the characters (numbers) representing tremor levels "2", "5", and "7" below the threshold of "10" will be displayed in black. On the other hand, tremor levels "15", "23", and "26" exceeding the threshold of "10" will be displayed in red with a different font and font size than those representing tremor levels "2", "5", and "7" below the threshold of "10", as shown in Figure 8B. Furthermore, the above threshold may be adjustable to any size by user operation using the input unit 12.

[0096] Furthermore, if the control unit 20 determines in step S203 that display mode B is specified, it causes the display unit 16 to perform a process to display the link (node) corresponding to that rank in a color corresponding to the magnitude of the shaking level (step S205). Specifically, the control unit 20 converts the entire specified map area into a black and white line drawing, divides the range from the minimum to the maximum value that can be taken as the magnitude of the shaking level into multiple ranks, and displays the link or node corresponding to that rank in a different color (for example, green, red, blue, yellow) for each rank, as shown in Figure 8C.

[0097] Furthermore, if it is determined in step S203 that display mode C is specified, the control unit 20 causes the display unit 16 to display a map in which, among the links or nodes included in the specified map area, only those links or nodes corresponding to shaking levels exceeding the threshold described above are shown in a color indicating a warning (step S206). For example, as shown in Figure 8D, the control unit 20 displays links or nodes corresponding to shaking levels of threshold "10" or less in black, and displays links or nodes corresponding to shaking levels exceeding the predetermined threshold "10" in red to indicate a warning.

[0098] Therefore, by executing steps S204, S205, or S206 described above, information representing the degree of shaking at each link or node is presented within the map area shown in Figures 8A to 8D.

[0099] Here, for example, when the display shown in Figure 8A is shown, if the user performs an operation to increase the scale of the displayed map, the control unit 20 causes the display unit 16 to display a wider area map, including the area enclosed by the dashed line as shown in Figure 9, while the designated map area shown in Figure 8A is reduced in size. Furthermore, in response to this operation to increase the scale, the control unit 20 calculates the average value of the vibration penalty value corresponding to each link in each link group, for each group of links consisting of a series of links connected within the designated map area shown in Figure 9. The control unit 20 then uses the character (number) representing this average value as the vibration level and causes the display unit 16 to display a map in the vicinity of the corresponding link group.

[0100] Incidentally, the driver assistance computer 60, along with the driver assistance device 10, is equipped with a program that includes a vibration level display routine that controls the vibration level display function described above. Furthermore, the driver assistance computer 60 includes a communication unit, input unit, map data acquisition unit, display unit, and control unit that can operate in the same manner as the communication unit 11, input unit 12, map data acquisition unit 14, display unit 16, and control unit 20 included in the driver assistance device 10.

[0101] Therefore, the control unit (CPU: central processing unit) of the driver assistance computer 60 executes the vibration level display routine shown in Figure 5 in response to a vibration level display command that includes information indicating the departure point, destination, planned travel time, and display mode entered by the user. As a result, the driver assistance computer 60, like the driver assistance device 10, displays a map in which the vibration level is shown as shown in Figures 8A to 8D and Figure 9 in a designated map area that includes the departure point and destination specified by the user.

[0102] Therefore, by referring to maps showing vibration levels, such as those shown in Figures 8A to 8D and Figure 9, users can determine the magnitude of vibration that their vehicle will experience when traveling along road links and nodes within a specified map area. This allows users to select and drive on routes that will produce a desired level of vibration.

[0103] In the above embodiment, the process of displaying a map showing the shaking levels as shown in Figures 8A to 8D or Figure 9 is performed by software as shown in Figure 5, but this may also be implemented in hardware.

[0104] In short, the driver assistance system should include the following: a sway penalty database, a map database, a sway penalty value acquisition unit, and a display control unit.

[0105] The sway penalty database (52) stores sway index formulas and actual sway index formulas that correspond to the magnitude of sway experienced by a moving object traveling on each road link based on map data.

[0106] The map database stores a tremor index formula or an actual tremor index formula, which is stored and managed by the tremor penalty database. Here, the tremor penalty value is calculated from the map database using the tremor index formula or actual tremor index formula corresponding to the link (node) specified by the tremor penalty value acquisition unit (20, S200 to S202).

[0107] The shake penalty value acquisition unit (20, S200-S202) acquires shake penalty values ​​from the map database that correspond to each link included in the map information of the specified map area specified by the user.

[0108] The display control unit (20, S203 to S206) displays a map of a designated map area on the display (16), and visually displays information representing the level of shaking based on each of the shaking penalty values ​​obtained from the map database on the displayed map so that it can be associated with each of the links.

[0109] 10 Driving support device 12 Input unit 13 Acceleration sensor 14 Map data acquisition unit 15 Position detection unit 16 Display unit 17 Audio output unit 20 Control unit 21 Non-volatile memory 50 Server 52 Vibration penalty database 100 Driving support system

Claims

1. A driving assistance device comprising: a map database storing map data; a vibration penalty database that manages vibration index formulas or actual vibration index formulas corresponding to the magnitude of vibrations experienced by a moving object traveling along a road link based on the map data; a vibration penalty value acquisition unit that acquires vibration penalty values ​​from the map database, corresponding to each of the links included in the map information of a designated map area specified by the user, using vibration penalty index formulas or actual vibration index formulas stored in the map database to calculate vibration penalty values; and a display control unit that displays a map of the designated map area on a display and displays information representing the level of vibration based on each of the acquired vibration penalty values ​​on the displayed map in a way that allows visual association with each of the links.

2. The driving support device according to claim 1, characterized in that the display control unit displays characters indicating the level of shaking as information near each of the corresponding links in the designated map area.

3. The driving support device according to claim 2, characterized in that the display control unit sets a threshold for each of the levels of shaking individually, and displays, among the levels of shaking corresponding to each of the links in the designated map area, characters indicating the level of shaking that exceeds the corresponding threshold and characters indicating the level of shaking that is less than or equal to the threshold, in different colors, character sizes, and fonts.

4. The driving assistance device according to claim 3, characterized in that when the display control unit receives an operation to increase the scale of the map in the designated map area, it calculates the average value of the vibration level corresponding to each link in the link group for each group of links consisting of a series of links connected in the designated map area, and displays the character representing the average value near the corresponding link group.

5. The driving assistance device according to claim 1, characterized in that the display control unit displays each of the links in the designated map area in a color corresponding to the magnitude of the vibration level corresponding to that link.

6. The driving assistance device according to claim 5, characterized in that the display control unit displays the designated map area as a black and white line drawing, divides the range from the lowest to the highest possible level of shaking into multiple ranks, and displays each of the links included in the designated map area in a color corresponding to the rank to which the level of shaking corresponding to that link belongs.

7. The driving support device according to claim 5, characterized in that the display control unit displays only the links in the designated map area whose corresponding level of shaking exceeds a predetermined threshold in a predetermined color to indicate a warning.

8. The driving support device according to claim 3 or 7, characterized in that the threshold is adjustable by user operation.

9. A driving assistance method characterized by: obtaining the vibration penalty value calculated using a vibration penalty database that stores vibration index formulas or actual vibration index formulas corresponding to the magnitude of vibration experienced by a moving object traveling along a link, which are associated with each road link based on map data stored in a map database; and, while displaying the map of the specified map area on a display, displaying information representing the level of vibration based on each of the acquired vibration penalty values ​​on the displayed map so that it can be visually associated with each of the links.

10. A program to be executed by a computer, comprising the steps of: obtaining a vibration penalty value calculated using a vibration penalty database that stores vibration index formulas or actual vibration index formulas corresponding to the magnitude of vibration experienced by a moving object traveling along a link, which are associated with each road link based on map data stored in a map database, and which are stored in the vibration penalty database as vibration penalty index formulas for each link, from among the vibration index formulas or actual vibration index formulas for each link stored in the map database as vibration penalty index formulas for each link, which are included in the map information of a specified map area specified by the user; and displaying a map of the specified map area on a display, and displaying information representing the level of vibration based on each of the obtained vibration penalty values ​​on the displayed map in a way that can be visually associated with each of the links.

11. A storage medium characterized in that it stores the program described in claim 10.

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