JP2008114666A - Degradation state determining device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To properly grasp a degradation state of chassis components of a vehicle, and to issue a warning with proper contents at a proper timing, by determining a degradation state of the chassis components of the vehicle on the basis of a road surface state or a vehicle state. <P>SOLUTION: The degradation state determining device comprises a data retracting portion storing portion storing map data, a present position detecting processing portion detecting a present position of a vehicle, information collecting portion obtaining information indicating the road surface state and a vehicle state at the present position, a degradation state determining portion determining the degradation state of the chassis components of the vehicle on the basis of the road surface state and the vehicle state, and a warning portion issuing a warning corresponding to the degradation state of the chassis components. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a deterioration state determination apparatus.

Conventionally, in a navigation device mounted on a vehicle such as an automobile, an optimum route from a set departure point to a destination is searched based on road map data and displayed on a display means. . In addition, a navigation device has also been proposed that displays a warning regarding maintenance of consumables such as engine oil and tires on a display unit based on the travel distance of the vehicle (see, for example, Patent Document 1).
JP-A-9-115097

  However, in the conventional navigation device, since the warning is displayed based on the statistical average value of the travel distance regarding the consumption state of the consumables, the original maintenance time cannot be notified to the user. For example, in the case of tires, the degree of wear is severe in the case of driving with sudden start and braking frequently, so even if a tire replacement warning is displayed based on the average value of mileage, a warning that is too late End up. On the other hand, since the degree of wear is moderate in a gentle driving manner, even if a tire replacement warning is displayed based on the average value of the distance traveled, the warning is too early and too early.

  The present invention solves the above-mentioned conventional problems, and appropriately determines the deterioration state of the undercarriage parts of the vehicle by determining the deterioration state of the undercarriage parts of the vehicle based on the road surface state and the vehicle state. An object of the present invention is to provide a degradation state determination device capable of notifying a warning having an appropriate content at an appropriate time.

  Therefore, in the degradation state determination device of the present invention, a data storage unit that stores map data, a current position detection processing unit that detects the current position of the vehicle, and information indicating a road surface state and a vehicle state at the current position are provided. An information collecting unit to be acquired; a deterioration state determining unit that determines a deterioration state of the undercarriage component of the vehicle based on the road surface state and the vehicle state; and a warning unit that issues a warning corresponding to the deterioration state of the undercarriage component; Have

  According to the present invention, the deterioration state determination device determines the deterioration state of the undercarriage parts of the vehicle based on the road surface state and the vehicle state, and issues a warning based on the determination. As a result, it is possible to appropriately grasp the deterioration state of the undercarriage parts of the vehicle and notify a warning with appropriate contents at an appropriate time.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.

  FIG. 1 is a block diagram showing a configuration of a deterioration state determination apparatus according to an embodiment of the present invention.

  In the figure, reference numeral 10 denotes a navigation device as a deterioration state determination device according to an embodiment of the present invention, which is mounted on a vehicle, displays the current position of the vehicle on a map, and searches for a route to a destination. Normal navigation processing is performed, and the deterioration state of the undercarriage parts of the vehicle is determined. The vehicle may be of any type as long as it can travel on a road such as a passenger car, a truck, a bus, or a motorcycle. However, in the embodiment of the present invention, for convenience of explanation, the vehicle is The case of a passenger car having four wheels will be described.

  The navigation device 10 is connected to an external information providing device 20, a sensor unit 30, an external warning device 40, and an external storage device 50 so that they can communicate with each other. Here, the external information providing apparatus 20 includes a center system 21 and another navigation system 22. The center system 21 includes VICS (R) (Vehicle Information & Communication System) information, RDS-TMC (Radio Data System-Traffic Message Channel) information, police, Japan. It is a computer system disposed in an information center (not shown) that collects and distributes information such as traffic control systems such as road corporations and weather information. Thereby, the navigation device 10 can acquire information such as VICS (R) information, RDS-TMC information, traffic control system information, and weather information. The other navigation system 22 is a vehicle navigation device or a vehicle navigation system mounted on another vehicle. Thereby, what is called vehicle-to-vehicle communication can be performed, and various information such as the average vehicle speed and the degree of congestion acquired while other vehicles are traveling can be acquired.

  The sensor unit 30 is attached to the suspension of each wheel, and includes a load sensor 31 that detects a load received by the tire, a vertical acceleration sensor 32 that detects vertical acceleration of the vehicle, and G that detects acceleration in the longitudinal direction of the vehicle. It has a sensor 33, a gyro sensor 34 for detecting the rotational angular velocity of the vehicle, that is, a lateral acceleration, and a vehicle speed sensor 35 for detecting the vehicle speed. The sensor unit 30 is a GPS sensor that detects a current position on the earth by receiving radio waves transmitted from a GPS (Global Positioning System) satellite in order for the navigation device 10 to appropriately perform navigation processing, and driving. Steering sensor for detecting the steering angle of the vehicle operated by the driver, a winker sensor for detecting the operation of the winker as the direction indicator of the vehicle, an accelerator sensor for detecting the accelerator opening operated by the driver, and driving It is desirable to further include a brake sensor for detecting movement of a brake pedal of a vehicle operated by a person, a vehicle weight sensor for acquiring vehicle weight information, a geomagnetic sensor, a distance sensor, a beacon sensor, an altimeter, and the like. The sensor unit 30 may be separate from the navigation device 10, but may be integrated with the navigation device 10.

  Further, the external warning device 40 includes a display unit 41 and an audio output unit 42. The display unit 41 is a CRT, a liquid crystal display, an LED (Light Emitting Diode) display, a plasma display, a hologram device that projects a hologram on a windshield, etc., and includes operation guidance, operation menus, operation key guidance for the navigation device 10, A map, a route from the current position to the destination, guidance information along the route, a warning, and the like are displayed. The display unit 41 is preferably a touch panel that also functions as an input unit. In this case, the display unit 41 also displays operation switches such as operation keys and an operation menu. The voice output unit 42 includes a speaker, headphones, and the like, and outputs voice guidance information, warnings, and the like along the route. The external warning device 40 may be separate from the navigation device 10, but may be integrated with the navigation device 10.

  The external storage device 50 includes a storage medium such as a hard disk, DVD, or CD, includes a map database 51 as a data storage unit, and stores various data. The map database 51 includes various data files such as a map data file, an intersection data file, a node data file, a road data file, a facility information data file in which information on facilities such as hotels and gas stations in each region is stored. . The external storage device 50 may be separate from the navigation device 10, but may be integrated with the navigation device 10. The road data stored in the road data file includes the width, gradient, cant, altitude, bank, number of road lanes, points where the number of lanes decrease, In addition to the data such as points, data indicating the road surface type is included.

  The navigation device 10 is a kind of computer that includes a calculation means such as a CPU and an MPU, a storage means such as a semiconductor memory, a magnetic disk, and an optical disk, a communication interface, and the like. The GPS, geomagnetic sensor, distance sensor, steering sensor, A current position detection processing unit that detects a current position by a beacon sensor, a gyro sensor, etc., a data storage unit that stores map data including road data, search data, and the like, and is set based on input information A navigation processing unit for performing various arithmetic processes such as a route search process for searching for a route to a destination, a route travel guidance process, a POI (Point of Interest) search process for searching for points and facilities, and the like. And search for the route to the set destination. You can give guidance.

  Further, the navigation device 10 includes a communication receiving unit 11, a sensor control unit 12, a wear state determination unit 13 as a deterioration state determination unit, a warning execution determination unit 14, and an external output interface 15. The communication receiving unit 11 communicates with the external information providing device 20 and acquires information on road surface conditions in addition to information such as VICS (R) information, RDS-TMC information, traffic control system information, weather information, and the like. To do. The sensor control unit 12 controls the operation of various sensors included in the sensor unit 30 and acquires information detected by the various sensors.

  And the said wear state determination part 13 determines the deterioration state of the vehicle suspension part based on the information which shows the road surface state and vehicle state which the said communication receiving part 11 and the sensor control part 12 acquired. In the embodiment of the present invention, only the case where the underbody part is a tire and the deteriorated state is a worn state will be described for convenience of explanation. In this case, the wear state determination unit 13 calculates the wear amount of each tire and determines the wear level of each tire.

  The warning execution determination unit 14 determines whether or not to notify the user of a warning based on the wear level of each tire determined by the wear state determination unit 13 and the content of the warning to be notified. Then, the warning execution determination unit 14 instructs the external warning device 40 to output via the external output interface 15 and outputs a warning of the determined content.

  Furthermore, the navigation device 10 includes an information collecting unit that acquires information indicating a road surface state and a vehicle state at the current position, and a warning unit that issues a warning corresponding to a tire deterioration state from the viewpoint of functions.

  Next, the operation of the navigation device 10 having the above configuration will be described. First, the overall operation will be described.

  FIG. 2 is a flowchart showing the overall operation of the deterioration state determination apparatus according to the embodiment of the present invention.

  First, when the engine of the vehicle is activated and the navigation device 10 starts operating, the navigation device 10 repeatedly executes a process as a deterioration state determination device at a predetermined cycle (for example, 1 to 100 [msec] cycle). And when the process as a degradation state determination apparatus is started, the navigation apparatus 10 will perform an information collection process first. In this case, the communication receiving unit 11 acquires information indicating the road surface state from the external information providing device 20, and the sensor control unit 12 is information indicating the vehicle state such as the vehicle speed, the longitudinal acceleration, and the lateral acceleration from the sensor unit 30. To get. Further, the cumulative amount of wear until the previous process of each tire calculated and stored in the previous process is also acquired from the external storage device 50.

  Subsequently, the navigation device 10 executes a wear amount calculation process. In this case, the wear state determination unit 13 is based on the road surface condition, the load of each tire, the slip of each tire, etc., and the instantaneous wear amount of each tire at the present time, that is, from the previous process to the present process, Calculate the amount of wear in a short time span. Then, a value obtained by adding the wear amount to the accumulated wear amount up to the previous process is calculated as an accumulated wear amount up to the current process, and the previous process stored in the external storage device 50 by the accumulated wear amount is calculated. Update cumulative wear.

  Subsequently, the navigation device 10 executes a wear level determination process. In this case, the wear state determination unit 13 determines a wear level based on the calculated cumulative wear amount up to the current process, and further determines a wear code corresponding to the determined wear level.

  Subsequently, the navigation device 10 executes notification determination processing and ends the processing. In this case, the wear state determination unit 13 determines whether or not to output a warning based on the determined wear code and the content of the warning, and causes the external warning device 40 to output the warning.

Next, a flowchart will be described.
Step S1: Information collection processing is executed.
Step S2: Wear amount calculation processing is executed.
Step S3 A wear level determination process is executed.
Step S4 The notification determination process is executed and the process is terminated.

  Next, a subroutine for information collection processing in step S1 will be described.

  FIG. 3 is a diagram showing classification of road surface conditions in the embodiment of the present invention, and FIG. 4 is a flowchart showing a subroutine of information collection processing in the embodiment of the present invention.

  The information collection process is roughly divided into an operation for determining the load received by the tire and an operation for determining the μ of the road surface.

  First, the navigation apparatus 10 acquires the cumulative amount of wear from the external storage device 50 up to the previous process of each tire calculated and stored in the previous process. Subsequently, the vehicle speed is obtained from the vehicle speed sensor 35 of the sensor unit 30, the vehicle longitudinal acceleration is obtained from the G sensor 33, and the vehicle lateral acceleration is obtained from the gyro sensor 34.

  Subsequently, the navigation device 10 determines whether or not the sensor unit 30 includes the load sensor 31. And when the load sensor 31 is included, the load which each tire receives from this load sensor 31 is acquired.

  When the load sensor 31 is not included, the navigation device 10 acquires the vehicle weight of the vehicle as a unique parameter. In this case, the acquired vehicle weight is a value obtained by adding the weight of the occupant detected by the occupant sensor disposed on the seat to the default vehicle weight value for each vehicle type. Note that the amount of suspension sinking when the vehicle is stopped may be measured using a sensor of an auto leveling device, and the vehicle weight may be calculated from the measured amount of sinking. Then, the load movement amount is calculated based on the longitudinal and lateral accelerations of the vehicle acquired from the G sensor 33 and the gyro sensor 34, and correction based on the load movement amount is performed to calculate the load received by each tire. Specifically, the calculation is performed as follows.

First, the load received by each tire when the vehicle is stopped is calculated by the following equation (1).
Load received by each tire = Load received by each wheel = vehicle weight / number of wheels (4) (1)
The load received by each tire during acceleration / deceleration is calculated by the following equation (2).
Load received by each tire = Load received by each wheel ± Amount of forward / backward load movement / 2 Formula (2)
here,
Front / rear load travel = pitching moment / wheel base (3)
Pitching moment = vehicle weight x longitudinal acceleration x height of center of gravity (4)
It is.

Moreover, the load which each tire receives at the time of turning right and left is calculated by the following formula (5).
Load received by each tire = Load received by each wheel ± Movement amount of left and right load / 2 (Expression (5))
here,
Left / right load travel = roll moment / wheel base (6)
Roll moment = vehicle weight x lateral acceleration x center of gravity height (7)
It is.

  The operation so far is an operation for determining the load received by the tire, and the subsequent operation is an operation for determining μ on the road surface.

  Subsequently, the navigation device 10 acquires the current position of the vehicle, that is, the own vehicle position. Then, it is determined whether there is inter-vehicle information as information from the other navigation system 22 or center information as information from the center system 21. Here, when there is neither vehicle-to-vehicle information nor center information, the road surface type at the vehicle position is acquired from the map database 51. When there is inter-vehicle information or center information, the road surface type at the vehicle position is acquired from the inter-vehicle information or center information. This is because the road surface type data included in the inter-vehicle information or the center information is considered to be newer and more accurate than the road surface type data stored in the map database 51.

  Subsequently, the navigation apparatus 10 acquires weather information at the vehicle position, acquires indoor / outdoor information indicating whether the vehicle position is indoor or outdoor, and ends the process. As for the weather information and the indoor / outdoor information, the information acquired in the own vehicle is the latest, so the inter-vehicle information or the center information is not used.

  The current road surface state at the vehicle position can be determined from the road surface type, weather information, and indoor / outdoor information acquired in this manner. The road surface state is classified as shown in FIG. 3, for example.

Next, a flowchart will be described.
Step S1-1: Accumulated wear amount of each tire until the previous process is acquired.
Step S1-2: The vehicle speed is acquired.
Step S1-3: Obtain the longitudinal acceleration.
Step S1-4: The lateral acceleration is acquired.
Step S1-5: It is determined whether or not the sensor unit 30 includes the load sensor 31. If the sensor unit 30 includes the load sensor 31, the process proceeds to step S1-6. If the sensor unit 30 does not include the load sensor 31, the process proceeds to step S1-7.
Step S1-6 The load received by each tire is acquired from the load sensor 31.
Step S1-7 Obtain the vehicle weight.
Step S1-8 The load movement amount is calculated based on the longitudinal and lateral accelerations, and the load received by each tire is calculated by performing correction based on the load movement amount.
Step S1-9: The own vehicle position is acquired.
Step S1-10: It is determined whether there is inter-vehicle information or center information. If there is inter-vehicle information or center information, the process proceeds to step S1-12, and if there is no inter-vehicle information or center information, the process proceeds to step S1-11.
Step S1-11: The road surface type at the vehicle position is acquired from the map database 51.
Step S1-12: The road surface type at the vehicle position is acquired from the inter-vehicle information or the center information.
Step S1-13: Obtain weather information at the vehicle position.
Step S1-14: Indoor / outdoor information indicating that the vehicle position is indoor or outdoor is acquired, and the process ends.

  Next, a subroutine for the wear amount calculation process in step S2 will be described.

  FIG. 5 is a diagram showing a dynamic friction coefficient corresponding to the road surface state in the embodiment of the present invention, and FIG. 6 is a flowchart showing a subroutine of wear amount calculation processing in the embodiment of the present invention.

  The cumulative amount of tire wear up to the present time is the cumulative amount of wear up to the previous treatment plus the instantaneous amount of wear at the current moment, that is, the amount of wear in the extremely short time span from the previous treatment to the current treatment. Can be considered. Further, the calculation formula used to calculate the wear amount is different between when the tire is slipping and when it is not slipping. The cumulative wear amount is calculated for each tire.

  First, the navigation device 10 determines the road surface state based on a combination of the road surface type, weather information, and indoor / outdoor information at the vehicle position acquired in the information collection process, and determines the road surface state based on the determined road surface state. The μ of the road surface, that is, the coefficient of friction between the road surface and the tire is determined. The friction coefficient is a dynamic friction coefficient. The relationship between the road surface condition and the dynamic friction coefficient can be associated as shown in FIG. 5 (see, for example, http://www.asahi-net.or.jp/zi3-kwrz/carstop.html).

  Subsequently, the navigation device 10 determines the load received by each tire acquired in the information collection process, further determines the slip of each tire, and determines whether or not the tire is slipping. Then, the wear amount of the tire when the tire is slipping and when the tire is not slipping is calculated.

Here, when the tire is slipping, that is, when wheel spin is generated, the amount of wear of the tire is proportional to the dynamic frictional force, and is calculated by the following equation (8).
Tire wear amount = dynamic friction force × 1 / tire hardness × distance × constant (8)
The tire hardness is a coefficient indicating that the tire rubber is softer as the numerical value is smaller, and can be measured by a hardness meter. For example, the tire hardness of a typical automobile studless tire is 54 to 56 at room temperature. The tire hardness changes depending on the tire temperature and the aging of the tire, but here, the tire temperature and the aging of the tire are not considered.

The dynamic friction force is calculated by the following equation (9).
Dynamic friction force = Dynamic friction coefficient x Tire load x Gravity acceleration (9)
On the other hand, when the tire is not slipping, that is, when the wheel spin is not generated, the wear amount of the tire is proportional to the external force that is the force in the vertical direction or the horizontal direction. Calculated.
Tire wear amount = external force × 1 / tire hardness × distance × constant (10)
The external force is calculated by the following equation (11).
External force = tire load x gravitational acceleration (11)
The limit of the external force is static friction coefficient × tire load × gravity acceleration.

  In this way, after calculating the instantaneous wear amount at the present time, the navigation apparatus 10 adds the instantaneous wear amount at the current time to the accumulated wear amount up to the previous process, and the accumulated wear amount up to the current process. Get. The wear amount of each tire can also be calculated by a known method other than the method described above (see, for example, JP-A Nos. 11-326143 and 2005-47295).

  And the navigation apparatus 10 preserve | saves the accumulated amount of wear until this process, and complete | finishes a process. As a result, the cumulative amount of wear up to the previous process stored in the external storage device 50 is updated with the cumulative amount of wear up to the current process.

Next, a flowchart will be described.
Step S2-1: The coefficient of friction between the road surface and the tire is determined.
Step S2-2: Determine the load received by each tire.
Step S2-3: Slip of each tire is determined.
Step S2-4: It is determined whether or not the tire is slipping. If the tire is slipping, the process proceeds to step S2-5. If the tire is not slipping, the process proceeds to step S2-6.
Step S2-5: The amount of wear of the tire when the tire is slipping is calculated.
Step S2-6: Calculate the amount of tire wear when the tire is not slipping.
Step S2-7 The instantaneous wear amount at the present time is added to the accumulated wear amount up to the previous processing to obtain the accumulated wear amount up to the current processing.
Step S2-8: The accumulated amount of wear up to the current process is stored, and the process ends.

  Next, a subroutine for the wear level determination process in step S3 will be described.

  FIG. 7 is a diagram showing a wear code corresponding to the wear level in the embodiment of the present invention, and FIG. 8 is a flowchart showing a subroutine of wear level determination processing in the embodiment of the present invention.

  First, the navigation apparatus 10 determines the wear level of each tire based on the accumulated wear amount up to the current process acquired in the wear amount calculation process. The wear level is set in advance so as to have a plurality of stages according to the amount of accumulated wear. Here, the description will be made assuming that the wear level is set to three levels of wear, that is, small, medium and large, from the new state to the limit state of safety performance.

  A large wear level corresponds to a state in which wear has progressed 100% or more from a new state when the tire is purchased. That is, the remaining width of the tire is 1.6 [mm] or less and a slip sign is present. This state is a dangerous state that does not pass the vehicle inspection.

  Further, during the wear level, it corresponds to a state in which 50 to 100% wear has progressed from the new state when the tire is purchased. That is, the tire braking force is slightly reduced, and if the person is familiar with automobiles, the tire is rotated.

  Further, the low wear level corresponds to a state in which 0 to 50% wear has progressed from the new state when the tire is purchased. That is, the tire braking force is sufficient.

  Then, the navigation device 10 determines whether the cumulative amount of wear up to the current process corresponds to small, medium, or large.

  Subsequently, the navigation device 10 determines a wear code corresponding to the wear level, and ends the process. For example, as shown in FIG. 7, the wear codes are set in advance from 1 to 7 in accordance with the balance between the wear level of each tire and the wear level between tires. The wear code is not limited to the example shown in FIG. 7 and can be arbitrarily set.

Next, a flowchart will be described.
Step S3-1: It is determined whether the cumulative amount of wear up to the current process corresponds to small, medium or large.
Step S3-2: The wear code corresponding to the wear level is determined, and the process is terminated.

  Next, the notification determination process subroutine in step S4 will be described.

  FIG. 9 is a flowchart showing a subroutine of notification determination processing in the embodiment of the present invention.

  First, the navigation device 10 determines whether or not to notify the user of a warning based on the wear code determined in the wear level determination process. That is, it is determined whether or not the determined wear code is a wear code to be notified of a warning. If it is not the wear code to be notified of the warning, the process is terminated as it is.

  If the wear code is a warning code to be notified, the navigation device 10 selects a warning voice corresponding to the wear code, that is, a warning content by voice. The content of the warning by voice is set in advance corresponding to the wear code as shown in FIG.

  Subsequently, the navigation device 10 selects a warning image corresponding to the wear code, that is, a warning content by the image. Note that the content of the warning by the image is also set in advance corresponding to the wear code, as shown in FIG.

  Then, the navigation device 10 issues a warning output instruction to the external warning device 40 via the external output interface 15, and ends the processing. Thereby, the image of the selected content is displayed on the display unit 41, and the audio output unit 42 outputs the audio of the selected content. The warning includes contents for notifying the user of the wear level of the tire and guidance for replacing the tire. In this case, since a warning corresponding to the wear level is output, the user can accurately grasp the deterioration state of the tire and can take appropriate measures.

Next, a flowchart will be described.
Step S4-1: It is determined whether or not the determined wear code is a wear code to be notified of a warning. If the determined wear code is a wear code to be notified of a warning, the process proceeds to step S4-2. If the determined wear code is not a wear code to be notified of a warning, the process is terminated.
Step S4-2: The content of the warning by voice is selected.
Step S4-3: The content of the warning by the image is selected.
Step S4-4: A warning output instruction is issued to the external warning device 40, and the process is terminated.

  As described above, in the embodiment of the present invention, the navigation device 10 acquires information indicating the road surface state and information indicating the vehicle state, and based on the road surface state and the vehicle state, the tire is a suspension part of the vehicle. The deterioration state, that is, the wear level is determined, and a warning is notified based on the determined wear level. Thereby, since the wear level of a tire can be determined appropriately, a warning with an appropriate content can be notified to the user at an appropriate time.

  Therefore, since the warning is not notified too early, unnecessary tire replacement is not performed according to the warning. Further, since the warning is not too late, the tire does not deteriorate too much.

  In the embodiment of the present invention, the case where the undercarriage part of the vehicle is a tire has been described. However, any kind of undercarriage part of the vehicle whose degree of deterioration is affected by the road surface state and the vehicle state may be used. For example, a brake pad for a brake device that decelerates or stops the rotation of a wheel, a hydraulic damper that is a damping device provided in the suspension of the wheel, a rubber bush interposed in a joint of a link member of the suspension, an axle bearing It may be a dust cover or the like for covering.

  The present invention is not limited to the above-described embodiment, and various modifications can be made based on the spirit of the present invention, and they are not excluded from the scope of the present invention.

It is a block diagram which shows the structure of the degradation state determination apparatus in embodiment of this invention. It is a flowchart which shows the whole operation | movement of the degradation state determination apparatus in embodiment of this invention. It is a figure which shows the division of the road surface state in embodiment of this invention. It is a flowchart which shows the subroutine of the information collection process in embodiment of this invention. It is a figure which shows the dynamic friction coefficient corresponding to the road surface state in embodiment of this invention. It is a flowchart which shows the subroutine of the abrasion amount calculation process in embodiment of this invention. It is a figure which shows the wear cord corresponding to the wear level in embodiment of this invention. It is a flowchart which shows the subroutine of the wear level determination process in embodiment of this invention. It is a flowchart which shows the subroutine of the notification determination process in embodiment of this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Navigation apparatus 13 Wear state determination part 51 Map database

Claims (5)

(A) a data storage unit for storing map data;
(B) a current position detection processing unit for detecting the current position of the vehicle;
(C) an information collecting unit that acquires information indicating a road surface state and a vehicle state at the current position;
(D) a deterioration state determination unit that determines the deterioration state of the undercarriage parts of the vehicle based on the road surface state and the vehicle state;
(E) A deterioration state determination device including a warning unit that issues a warning corresponding to a deterioration state of the underbody parts. The deterioration state according to claim 1, wherein the deterioration state determination unit determines a friction coefficient corresponding to the road surface state determined based on information indicating the road surface state, and determines the deterioration state according to the determined friction coefficient. Judgment device. The deterioration state determination device according to claim 1, wherein the deterioration state determination unit determines a load that the underbody component receives based on information indicating the vehicle state, and determines the deterioration state according to the determined load. The vehicle includes a plurality of undercarriage parts, the deterioration state determination unit determines a deterioration state of each undercarriage part, and the warning unit includes a deterioration state of each undercarriage part and a deterioration state between the undercarriage parts. The degradation state determination apparatus according to claim 1, wherein a warning corresponding to the balance of the selection is selected. The suspension part is a tire;
The deterioration determining unit determines a friction coefficient corresponding to the road surface state based on information indicating the road surface state, determines a load received by the tire based on the information indicating the vehicle state, and the friction coefficient and the load 2. The deterioration state determination device according to claim 1, wherein the wear amount of the tire is calculated based on and the deterioration state of the tire is determined based on the calculated wear amount.

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