EP3312397A1

EP3312397A1 - Oil life detection device and oil life detection method

Info

Publication number: EP3312397A1
Application number: EP16827413.2A
Authority: EP
Inventors: Ryutaro SENO
Original assignee: Panasonic Intellectual Property Management Co Ltd
Current assignee: Panasonic Intellectual Property Management Co Ltd
Priority date: 2015-07-17
Filing date: 2016-07-05
Publication date: 2018-04-25
Also published as: WO2017013845A1; EP3312397A4; JPWO2017013845A1; JP6503562B2

Abstract

Provided is oil remaining life detection device (1) that detects a remaining life of engine oil in vehicle (2), including: vehicle information acquisition part (21) that acquires, from vehicle (2), information relating to a travel distance of vehicle (2) and information relating to an driving state of an engine of vehicle (2) at every vehicle information acquisition period set in advance; engine state determination part (22) that determines the driving state of the engine during an engine state determination period set in advance, based on the information relating to the driving state of the engine; travel distance correction part (23) that corrects the travel distance of vehicle (2) during the engine state determination period according to the driving state of the engine to calculate a corrected driving distance; and oil remaining life calculation part (24) that subtracts the corrected driving distance from a residual remaining distance, which indicates the remaining life of engine oil, to calculate a new residual remaining distance. With this constitution, oil remaining life detection device (1) in the present disclosure is effective in detecting a remaining life of engine oil of a vehicle with greater accuracy.

Description

TECHNICAL FIELD

The present invention relates to an oil remaining life calculation device for detecting a remaining life of engine oil of a vehicle, and an oil remaining life calculation method.

BACKGROUND ART

Engine oil, which is used for an engine of a vehicle, plays roles such as lubrication, cooling, seal, flashing, and rust prevention of each part within the engine. As the engine oil is used, it deteriorates due to oxidization caused by heat generated in the engine, contamination caused by mixing of soot generated when gasoline is combusted, and the like. Accordingly, it is necessary to replace the engine oil periodically. Time to oil exchange engine oil is typically determined by a predetermined travel distance (e.g., 5000 km) or driving time (e.g., six months) as a standard.
The time to oil exchange engine oil, i.e., a remaining life of engine oil can typically be expressed by a residual remaining distance of engine oil or time. The residual remaining distance of engine oil or the time can be calculated such that an accumulated value of a travel distance of a vehicle or time is subtracted from the remaining distance or the time set in advance (see, e.g., Patent Literature 1).

Citation List

Patent Literature

PTL 1: Unexamined Japanese Patent Publication No. 2003-056324

SUMMARY OF THE INVENTION

An oil remaining life calculation device of the present disclosure, which is an oil remaining life calculation device for detecting a remaining life of engine oil of a vehicle, includes: a vehicle information acquisition part that acquires, from the vehicle, information relating to a travel distance of the vehicle and information relating to an driving state of an engine of the vehicle at every vehicle information acquisition period set in advance; an engine state determination part that determines the driving state of the engine during an engine state determination period set in advance, based on the information relating to the driving state of the engine; a travel distance correction part that corrects the travel distance of the vehicle during the engine state determination period according to the driving state of the engine to calculate a corrected driving distance; and an oil remaining life calculation part that subtracts the corrected driving distance from a residual remaining distance, which indicates the remaining life of engine oil, to calculate a new residual remaining distance.
With this constitution, the oil remaining life calculation device in the present disclosure is effective in detecting a remaining life of engine oil of a vehicle with greater accuracy.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a block diagram showing a schematic configuration of an oil remaining life detection device in accordance with the present disclosure.
FIG. 2 is a flowchart showing a flow of a oil remaining life detection process of engine oil by the oil remaining life detection device in accordance with the present disclosure.
FIG. 3 is a view explaining a process that determines an driving state of an engine based on water temperature of engine cooling fluid.
FIG. 4 is a flowchart for explaining a process that determines the driving state of an engine based on oil temperature of engine oil or water temperature of engine cooling fluid.
FIG. 5 is a flowchart for explaining a process that determines the driving state of the engine based on low-speed driving time of the vehicle.
FIG. 6 is a flowchart for explaining a process that determines the driving state of the engine based on idling time of the vehicle.
FIG. 7 is a view explaining a correction processing a travel distance when the driving state of the engine is determined based on the oil temperature of engine oil.

DESCRIPTION OF EMBODIMENT(S)

The degree of degradation of engine oil is greatly changed depending on an driving state of an engine. In other words, the degradation of engine oil will be promoted, if the driving state of the engine is in severe condition. Accordingly, in the case where the degradation of engine oil is promoted, the oil needs to be replaced a little earlier than a general standard. Therefore, the remaining life of engine oil is preferably detected not by merely using an accumulated value of a travel distance of a vehicle or time, but by considering the driving state of the engine.
By the way, in recent years, it has been standardized that Engine Control Unit (ECU) in a vehicle is equipped with an on-board diagnostic system that periodically monitors an engine key compornent, various kinds of automotive sensors, and the like to diagnose failure of the vehicle. Accordingly, if a vehicle information acquisition device is connected to the on-board diagnostic system via a standard type of connector, it will be possible to acquire various information (hereinafter, referred to as "vehicle information") such as information relating to failure of the vehicle, or operational information (e.g., vehicle speed, engine RPM(revolutions per minute), and accelerator position) of engine key compornents, sensors, or the like, from the on-board diagnostic system. Thus, if the vehicle information, which is acquired from the on-board information detection system such as an on-board diagnostic system, can be used to detect a remaining life of engine oil of the vehicle, the oil remaining life will be detected easily, which is desirable.
Hereinafter, exemplary embodiments will be described in detail with reference to the drawings, as necessary. However, description that is in more detail than necessary may be omitted. For instance, detailed description about already well-known matters and overlapped description about the substantially same configurations may be omitted. This is because the following description is avoided from being unnecessarily redundant, and a person skilled in the art is made to easily understand the present disclosure.
Note that, the accompanying drawings and the following description are provided for a person skilled in the art to fully understand the present disclosure, and do not intend to limit the subject matter described in claims.

(FIRST EXEMPLARY EMBODIMENT)

Hereinafter, a first exemplary embodiment will be described with reference to FIGS. 1 to 7.
FIG. 1 is a block diagram showing a schematic configuration of an oil remaining life detection device in accordance with the present disclosure. Oil remaining life detection device 1 can detect a remaining life of engine oil based on information relating to a travel distance of vehicle 2, which is acquired from an on-board diagnostic system mounted in vehicle 2, and information (hereinafter, referred to as "engine state information") relating to an driving state of an engine of vehicle 2.
Vehicle 2 is a well-known car that drives wheels by using power of an engine, a motor, or the like. Vehicle 2 includes Engine Control Unit (ECU) 11 that performs multiple-unit control relating to operation of vehicle 2 such as engine control, and connector part 12 disposed in the interior of the vehicle. ECU11 is equipped with a well-known on-board failure diagnostic (On-Board Diagnostics (OBD)) system, i.e., a failure diagnostic processing program. Connector part 12 is a data link connector of well-known OBD2 standards.
A user can connect oil remaining life detection device 1 to ECU11 (i.e., the on-board diagnostic system) via connector part 12. Note that, if oil remaining life detection device 1 is allowed to acquire the information relating to the travel distance of vehicle 2 and the engine state information from the on-board diagnostic system mounted in ECU11, the connection form between ECU11 and oil remaining life detection device 1 will not necessarily be limited to connector part 12.
Oil remaining life detection device 1 includes vehicle information acquisition part 21, engine state determination part 22, travel distance correction part 23, oil remaining life calculation part 24, oil remaining life storage part 25, and oil change determination part 26. Vehicle information acquisition part 21 acquires the information relating to the travel distance of vehicle 2 and the engine state information from the on-board diagnostic system mounted in ECU11 of vehicle 2 at every vehicle information acquisition period set in advance. Engine state determination part 22 determines the driving state of the engine during an engine state determination period set in advance, based on the engine state information. Travel distance correction part 23 corrects the total travel distance according to the driving state of the engine to calculate a corrected driving distance, while accumulating the travel distance of vehicle 2 during the engine state determination period to calculate a total travel distance during the engine state determination period. Oil remaining life calculation part 24 subtracts the corrected driving distance from a residual remaining distance, which is a remaining life of engine oil, to calculate a new residual remaining distance. Oil remaining life storage part 25 stores the new residual remaining distance. Oil change determination part 26 determines time to oil exchange engine oil based on the new residual remaining distance.
Oil remaining life detection device 1 includes CPU20 and memory 30. Memory 30 constitutes oil remaining life storage part 25. Further, memory 30 stores a program to be executed by CPU20. CPU20 executes the program stored in memory 30 to achieve various kinds of functions. In other words, by executing the program, CPU20 functions as vehicle information acquisition part 21, engine state determination part 22, travel distance correction part 23, oil remaining life calculation part 24, and oil change determination part 26.
FIG. 2 is a flowchart showing a flow of a oil remaining life detection process of engine oil by oil remaining life detection device 1. Note that, the process shown in FIG. 2 exemplarily shows that the process in step ST101 is performed during the engine state determination period (see below) and the processes subsequent to step ST102 are performed one by one after the engine state determination period.
First, in step ST101, vehicle information acquisition part 21 acquires the information relating to the travel distance of vehicle 2 and the engine state information from ECU11 via connector part 12 of vehicle 2 during a engine state determination period set in advance at every vehicle information acquisition period set in advance.
The engine state determination period may employ, for example, one driving cycle which is a period from when an ignition switch of the engine is turned on until when the ignition switch is turned off, but not limited to this. In this case, the total travel distance during the engine state determination period is a travel distance of vehicle 2 during the one driving cycle. Further, as the engine state determination period, a time interval with a predetermined length in the one driving cycle may be employed. In this case, the total travel distance during the engine state determination period is a travel distance of vehicle 2 during the time interval with a predetermined length.
The vehicle information acquisition period may be one second, for example. The information relating to the travel distance of vehicle 2 is, for example, speed of vehicle 2. Vehicle information acquisition part 21 can determine the travel distance of vehicle 2 based on the speed of vehicle 2. Note that, vehicle information acquisition part 21 may acquire the travel distance of the vehicle from ECU11 of vehicle 2 directly.
The engine state information is information relating to a load of the engine when the engine is operated. The engine state information, which is not limited to this, may employ at least one of oil temperature of engine oil, water temperature of engine cooling fluid, engine RPM(revolutions per minute) of the engine, intake manifold pressure, boost pressure, air intake quantity, throttle position, or accelerator position of vehicle 2.
Subsequently, in step ST102, engine state determination part 22 determines the driving state of the engine during the engine state determination period based on the engine state information that has been acquired from ECU11 of vehicle 2 through vehicle information acquisition part 21. Next, in step ST103, travel distance correction part 23 corrects the total travel distance according to the engine state information to calculate a corrected driving distance, while accumulating the travel distance of vehicle 2 during the engine state determination period to calculate a total travel distance. More specifically, with respect to the travel distance at every vehicle information acquisition period, travel distance correction part 23 performs the correction according to the engine state information during the vehicle information acquisition period. Travel distance correction part 23 calculates the sum of travel distance, after the correction, during each vehicle information acquisition period in the engine state determination period to obtain a corrected driving distance.
In subsequent step ST104, oil remaining life calculation part 24 subtracts the corrected driving distance, which is calculated by travel distance correction part 23, from the residual remaining distance that is stored in oil remaining life storage part 25 to calculate a new residual remaining distance. In subsequent step ST105, oil remaining life calculation part 24 causes oil remaining life storage part 25 to store the new residual remaining distance calculated above.
In step ST106, oil change determination part 26 determines time to oil exchange engine oil, based on the new residual remaining distance calculated by oil remaining life calculation part 24. In this manner, oil remaining life detection device 1 can detect a remaining life of engine oil, in consideration of the driving state of the engine, based on the information relating to the travel distance of vehicle 2 and the engine state information which are acquired from ECU11 of vehicle 2. Accordingly, the time to oil exchange engine oil can be determined based on the remaining life of engine oil detected above.
Next, the operation and process of each part of oil remaining life detection device 1 will be described.
Vehicle information acquisition part 21, which is connected to ECU11 (i.e., an on-board diagnostic system) via connector part 12, acquires the information relating to the travel distance of vehicle 2 and the engine state information from the on-board diagnostic system at every vehicle information acquisition period set in advance. Vehicle information acquisition part 21 is connected to engine state determination part 22 and travel distance correction part 23. The information relating to the travel distance of vehicle 2, which is acquired by vehicle information acquisition part 21, is inputted to travel distance correction part 23. Further, the engine state information of vehicles 2 is inputted to engine state determination part 22. Note that, if the travel distance is employed to determine the driving state of the engine, the information relating to the travel distance will also be inputted to engine state determination part 22.
Engine state determination part 22 determines the driving state of the engine during the engine state determination period, based on the engine state information of vehicle 2 inputted from vehicle information acquisition part 21. Specifically, at every vehicle information acquisition period, engine state determination part 22 firstly determines whether the engine is in usual condition or in severe condition. The driving state of the engine can be determined based on various kinds of engine state information such as oil temperature of engine oil and water temperature of engine cooling fluid. Vehicle information acquisition part 21 acquires the engine state information, which is used for a determination method employed by engine state determination part 22, from ECU11 of vehicle 2. Next, when the driving state of the engine is determined to be in severe condition, engine state determination part 22 detects elapsed time of the severe condition. The elapsed time of the severe condition during each vehicle information acquisition period in the engine state determination period is accumulated to calculate elapsed time of the severe condition during the engine state determination period.
Note that, in the case where the driving state of the engine is turned into the severe condition again within a short period of time after the severe condition ends, it can be deemed that the severe condition of the engine substantially continues. Accordingly, when detecting the elapsed time of the severe condition of the engine, engine state determination part 22 establishes a protection period (hereinafter, referred to as "protection time interval") with a predetermined length after the severe condition of the engine ends. In the case where the severe condition of the engine is detected again within the protection time interval, engine state determination part 22 may determine that the severe condition of the engine continues. By doing so, even in the case where the usual condition and the severe condition are repeated and the severe condition is deemed to be continued substantially, the elapsed time thereof can be detected.
In the case where the driving state of the engine is determined based on oil temperature of engine oil, engine state determination part 22 firstly determines whether or not the oil temperature of engine oil exceeds a threshold set in advance. When the oil temperature exceeds the threshold, engine state determination part 22 determines that the driving state of the engine is in severe condition. When the oil temperature is less than or equal to the threshold, engine state determination part 22 determines that the engine is in usual condition. The threshold may be set to, for example, 120°C. If the oil temperature of engine oil exceeds 120°C, the engine oil will deteriorate due to heat, so that the oil remaining life is shortened. When the driving state of the engine is determined to be in severe condition, engine state determination part 22 detects elapsed time of the severe condition.
Instead of the oil temperature of engine oil, water temperature of engine cooling fluid may be employed. In this case, engine state determination part 22 determines whether or not the water temperature of engine cooling fluid exceeds a threshold set in advance. When the water temperature exceeds the threshold, engine state determination part 22 determines that the driving state of the engine is in severe condition. When the water temperature is less than or equal to the threshold, engine state determination part 22 determines that the engine is in usual condition. The threshold may be set to, for example, 100°C. When the driving state of the engine is determined to be in severe condition, engine state determination part 22 detects elapsed time of the severe condition.
FIG. 3 is a view for explaining a process that determines the driving state of the engine based on the water temperature of engine cooling fluid. In the example of FIG. 3, when the water temperature of engine cooling fluid exceeds 100°C, the driving state of the engine is determined to be in severe condition. In the example of FIG. 3, as the engine state determination period, time intervals with a predetermined length within one driving cycle are employed. Accordingly, in the example of FIG. 3, a total travel distance during the engine state determination period is the travel distance of vehicle 2 during the time intervals with a predetermined length.
With reference to FIG. 3, the beginning of severe condition (high load) is detected at time T1, and the end of the severe condition is detected at a corresponding one of time T2, time T3, and time T4. Note that, the high load, described herein, means that the driving state of the engine is in severe condition. At the corresponding one of time T2, time T3, and time T4, i.e., at the time when the end of the severe condition is detected, protection time interval t1 with a predetermined length is established after the severe condition ends. After the severe condition ends at time T2, severe condition is detected again within protection time interval t1 (see the portion surrounded by dashed line circle A). Thus, the severe condition is deemed to be continued after time T2. Similarly, after the severe condition ends at time T3, severe condition is detected again within protection time interval t1 (see the portion surrounded by dashed line circle B). Thus, the severe condition is deemed to be continued after time T3. However, after the severe condition ends at time T4, severe condition is not detected again within protection time interval t1 (see the portion surrounded by dashed line circle C). Therefore, the severe condition is deemed to end after time T4. Accordingly, it can be considered that the severe condition is continued from time T1 to time T4 and the severe condition ends at time T4. This makes it possible to detect elapsed time of the time interval (high load time interval) in which severe condition and usual condition are repeated and the severe condition is deemed to be continued substantially.
Similarly, in the example of FIG. 3, the beginning of severe condition is detected at time T5, and the end of severe condition is detected at a corresponding one of time T6 and time T7. At the corresponding one of time T6 and time T7, i.e., at the time when the end of severe condition is detected, protection time interval t1 with a predetermined length is established after the severe condition ends. After the severe condition ends at time T6, the severe condition is detected again within protection time interval t1 (see the portion surrounded by dashed line circle D). Thus, the severe condition is deemed to be continued after time T6. However, after the severe condition ends at time T7, the severe condition is not detected again within protection time interval t1 (see the portion surrounded by dashed line circle E). Therefore, the severe condition is deemed to end after time T7. Accordingly, it can be considered that the severe condition is continued from time T5 to time T7 and the severe condition ends at time T7. This makes it possible to detect elapsed time of the time interval (high load time interval) in which severe condition and usual condition are repeated and the severe condition is deemed to be continued substantially.
FIG. 4 is a flowchart for explaining a process that determines the driving state of the engine based on oil temperature of engine oil or water temperature of engine cooling fluid. The determination process shown in the flowchart of FIG. 4 is an exemplary process in the step (step ST102) that determines the driving state of the engine in the flowchart of FIG. 2. According to the present exemplary embodiment, the determination process of FIG. 4 is performed after the engine state determination period. In the determination process of FIG. 4, as the engine state determination period, a time interval with a predetermined length within one driving cycle is employed. Therefore, in the example of FIG. 4, a total travel distance during the engine state determination period is the travel distance of vehicle 2 during the time interval with a predetermined length.
To perform the determination process of FIG. 4, the driving state is determined at every vehicle information acquisition period. First, in step ST201, engine state determination part 22 determines an initial vehicle information acquisition period during the engine state determination period as a target time period.
In step ST202, based on the engine state information during the target time period, engine state determination part 22 determines whether or not the severe condition has been detected as the driving state of the engine. As mentioned above, the determination can be performed by comparing oil temperature of engine oil (or water temperature of engine cooling fluid) with a threshold set in advance. When it is determined that the severe condition has been detected, the step is progressed to step ST203. When it is determined that the severe condition has not been detected, the step is progressed to step ST209.
In step ST203, engine state determination part 22 determines that the high load time interval, which serves as elapsed time of the severe condition, is started in the target time period.
In next step ST204, engine state determination part 22 updates the target time period to the next vehicle information acquisition period.
In subsequent step ST205, based on the engine state information during the updated target time period, engine state determination part 22 determines whether or not the severe condition has been detected as the driving state of the engine. Similarly in step ST202, the determination can also be performed by comparing oil temperature of engine oil (or water temperature of engine cooling fluid) with the threshold set in advance. When it is determined that the severe condition has been detected, the step is returned back to step ST204. When it is determined that the severe condition has not been detected, the step is progressed to step ST206.
In step ST206, engine state determination part 22 determines whether or not an elapsed time from when the driving state of the engine is no longer in the severe condition exceeds the protection period (protection time interval) with a predetermined length. When it is determined that the elapsed time has exceeded the protection period, the step is progresses to step ST207. When it is determined that the elapsed time has not exceeded the protection period, the step is returned back to step ST204.
In step ST207, engine state determination part 22 determines that the high load time interval is completed in the target time period.
In subsequent step ST208, engine state determination part 22 calculates elapsed time of the high load time interval. The elapsed time can be calculated as an elapsed time from when it is determined that the high load time interval is started in step ST203 until when it is determined that the high load time interval is completed in step ST207.
In subsequent step ST209, engine state determination part 22 determines whether the engine state determination period is completed or not. When it is determined that the engine state determination period is completed, the process is ended. When it is determined that the engine state determination period is not completed, the step is progressed to step ST210.
In step ST210, engine state determination part 22 updates the target time period to the next vehicle information acquisition period, and the process is returned back to step ST202.
By doing so, when the driving state of the engine is in the severe condition, the high load time interval, which is the time interval in which severe condition and usual condition are repeated and the severe condition is deemed to be continued substantially, and the elapsed time of the high load time interval can be detected. Engine state determination part 22 can determine that the driving state of the engine during the high load time interval is the severe condition, and the driving state of the engine during a time interval other than the high load time interval is the usual condition.
Further, engine state determination part 22 can determine the driving state of the engine based on engine RPM(revolutions per minute) of the engine, intake manifold pressure, boost pressure, air intake quantity, throttle position, or accelerator position of vehicle 2. In this case, engine state determination part 22 determines whether or not the engine RPM(revolutions per minute), the intake manifold pressure, the boost pressure, the air intake quantity, the throttle position, or the accelerator position exceeds a threshold set in advance. When the engine RPM(revolutions per minute) or the like exceeds the threshold, engine state determination part 22 determines that the driving state of the engine is in severe condition. When the engine RPM(revolutions per minute) or the like is less than or equal to the threshold, engine state determination part 22 determines that the driving state of the engine is in usual condition. When the driving state of the engine is determined to be in severe condition, engine state determination part 22 detects elapsed time of the severe condition. Further, instead of the elapsed time, a proportion of a period of time when the engine RPM(revolutions per minute), the intake manifold pressure, the boost pressure, the air intake amount, the throttle position, or the accelerator position exceeds the threshold set in advance to a period set in advance, i.e., frequency of occurrence may be employed. For instance, there is supposed a proportion of a period of time when the engine RPM(revolutions per minute) exceeds a threshold set in advance to a period set in advance. When the proportion exceeds a predetermined proportion, the driving state of the engine may be determined to be in the severe condition.
Further, engine state determination part 22 can determine the driving state of the engine based on low-speed driving time or idling time of vehicle 2 in the engine state determination period. FIG. 5 is a flowchart for explaining a process that determines the driving state of the engine based on low-speed driving time of vehicle 2. The determination process shown in the flowchart of FIG. 5 is an exemplary process in the step (step ST102) that determines the driving state of the engine in the flowchart of FIG. 2. The determination process of FIG. 5 employs one driving cycle as the engine state determination period. Accordingly, in the example of FIG. 5, a total travel distance during the engine state determination period is the travel distance of vehicle 2 during the one driving cycle. Note that, the determination process of FIG. 5 is performed at every one driving cycle. Therefore, the high load time interval and the protection time interval are not set, unlike the determination process (see FIGS. 3 and 4) performed based on oil temperature of engine oil or water temperature of engine cooling fluid.
With reference to FIG. 5, in step ST301, engine state determination part 22 firstly detects a period of time (low-speed driving time) when vehicle 2 travels at a speed of less than threshold th1 set in advance. Specifically, engine state determination part 22 determines whether or not the speed of vehicle 2 is less than threshold th1 at every time interval with a predetermined length (e.g., per one second). Engine state determination part 22 calculates the low-speed driving time based on the result of determination. Threshold th1 may be 30 km/h, for example. In subsequent step ST302, engine state determination part 22 determines whether or not a ratio of a period of low-speed driving time to the engine state determination period, i.e., the one driving cycle, exceeds threshold th2 set in advance. When it is determined that the ratio of the period of low-speed running time to the engine state determination period exceeds threshold th2, the step is progresses to step ST303. When it is determined that the ratio is less than or equal to threshold th2, the process is ended. In step ST303, engine state determination part 22 determines that the driving state of the engine is in severe condition. In the determination process, the driving state of the engine is determined to be in severe condition or to be in usual condition, over the entire engine state determination period.
FIG. 6 is a flowchart for explaining a process that determines the driving state of the engine based on idling time of vehicle 2. The determination process shown in the flowchart of FIG. 6 is an exemplary process in the step (step ST102) that determines the driving state of the engine in the flowchart of FIG. 2. The determination process of FIG. 6 employs one driving cycle as the engine state determination period. Therefore, in the example of FIG. 6, a total travel distance during the engine state determination period is the travel distance of vehicle 2 during the one driving cycle. Note that, the determination process of FIG. 6 is performed at every one driving cycle. Therefore, the high load time interval and the protection time interval are not set, unlike the determination process (see FIGS. 3 and 4) performed based on oil temperature of engine oil or water temperature of engine cooling fluid.
With reference to FIG. 6, in step ST401, engine state determination part 22 firstly detects a period of time (idling time) when vehicle 2 is in an idling state. Specifically, engine state determination part 22 determines whether vehicle 2 is in the idling state or not at every time interval with a predetermined length (e.g., per one second). Engine state determination part 22 calculates idling time based on the result of determination. To determine whether vehicle 2 is in the idling state or not, it may be detected whether or not engine RPM(revolutions per minute) or throttle position is less than or equal to a predetermined threshold. In subsequent step ST402, engine state determination part 22 determines whether or not a ratio of a period of idling time to the engine state determination period, i.e., the one driving cycle, exceeds threshold th3 set in advance. When it is determined that the ratio of the period of idling time to the engine state determination period exceeds threshold th3, the step is progresses to step ST403. When it is determined that the ratio is less than or equal to threshold th3, the process is ended. In step ST403, engine state determination part 22 determines that the driving state of the engine is in severe condition. In the determination process, the driving state of the engine is determined to be in severe condition or to be in usual condition, over the entire engine state determination period.
Further, the driving state of the engine may be determined based on the sum of low-speed driving time and idling time of vehicle 2. In this case, when a ratio of a period of the sum of low-speed running time and idling time to the engine state determination period exceeds a threshold set in advance, the driving state of the engine is determined to be in severe condition. As the engine state determination period, one driving cycle may be employed, for example.
Further, engine state determination part 22 can determine the driving state of the engine based on a total travel distance during the engine state determination period. In this case, engine state determination part 22 determines whether or not the total travel distance during the engine state determination period is less than a threshold set in advance. When the total travel distance is less than the threshold, engine state determination part 22 determines that the driving state of the engine is in severe condition. When the total travel distance is more than or equal to the threshold, engine state determination part 22 determines that the driving state of the engine is in usual condition. As the engine state determination period, one driving cycle may be employed, for example. In the determination process, the driving state of the engine is determined to be in severe condition or to be in usual condition, over the entire engine state determination period.
By doing so, engine state determination part 22 can determine the driving state of the engine during the engine state determination period set in advance, based on the engine state information of vehicle 2 inputted from vehicle information acquisition part 21. The result of determination in engine state determination part 22 is inputted to travel distance correction part 23.
First, travel distance correction part 23 accumulates the travel distance of vehicle 2 during the engine state determination period to calculate a total travel distance during the engine state determination period. To calculate a corrected total travel distance (hereinafter, referred to as "corrected driving distance"), the total travel distance during the engine state determination period is corrected based on the result of determination in engine state determination part 22. More specifically, with respect to the travel distance at every vehicle information acquisition period, travel distance correction part 23 performs the correction according to the engine state information during the vehicle information acquisition period. Travel distance correction part 23 calculates the sum of travel distance, after the correction, during each vehicle information acquisition period in the engine state determination period to obtain a corrected driving distance.
For the correction, travel distance correction part 23 performs the correction such that the travel distance when the driving state of the engine is in severe condition is larger than an actual travel distance. The correction can be performed using a weighted coefficient that is set according to the driving state of the engine. In other words, the corrected driving distance is obtained as a travel distance reflecting the degradation of engine oil resulting from severe condition of the engine, rather than a travel distance obtained by merely accumulating the travel distance of vehicle 2 during the engine state determination period.
Further, in the case where a weighted coefficient according to elapsed time of severe condition is employed, the travel distance when the driving state of the engine is in severe condition can be corrected according to the elapsed time of the severe condition. For instance, when the engine is in usual condition, the weighted coefficient is set to 1, and according to the elapsed time of the severe condition, when the driving state of the engine is in the severe condition, the weighted coefficient is set to 1.1 to 2. Note that, these values of the weighted coefficient are an example and not limited to this. Further, the weighted coefficient may be changed depending on kinds of engine oil (i.e., oil viscosity and a oil grade) and volume of engine oil, as necessary.
FIG. 7 is a view for explaining a process that corrects a travel distance when the driving state of the engine is determined based on oil temperature of engine oil. With reference to FIG. 7, a correction processing method of the travel distance using a weighted coefficient will be described. In the example of FIG. 7, when oil temperature of engine oil exceeds 120°C, travel distance correction part 23 determines that the driving state of the engine is in severe condition. In A interval (the interval surrounded by dashed line circle A) and B interval (the interval surrounded by dashed line circle B) of FIG. 7, the weighted coefficient is set to "1.2," because elapsed time of the severe condition is short. In C interval (the interval surrounded by dashed line circle C), the weighted coefficient is set to "1.5," because C interval is longer than A interval and B interval, although elapsed time of the severe condition is short. In D interval (the interval surrounded by dashed line circle D), the weighted coefficient is set to "2," because elapsed time of the severe condition is long.
Travel distance correction part 23 multiplies the travel distance during a usual condition interval (an interval other than A to D intervals) by 1, as the weighted coefficient. Further, travel distance correction part 23 multiplies the travel distances during the severe condition intervals (A to D intervals) by 1.2 to 2, as the weighted coefficient according to the elapsed time of the severe condition. In other words, the travel distance during A interval and B interval is multiplied by 1.2 as the weighted coefficient, the travel distance during C interval is multiplied by 1.5 as the weighted coefficient, and the travel distance during D interval is multiplied by 2 as the weighted coefficient. By doing so, the travel distance during each severe condition interval can be corrected, according to the elapsed time of the severe condition, such that the corrected driving distance is larger than an actual travel distance.
Note that, in the example of FIG. 7, an actual travel distance is multiplied by the weighted coefficient to correct the travel distance, but a correction processing method of the travel distance using a weighted coefficient is not limited to this. Other various kinds of methods may be employed. For instance, travel distance correction part 23 may add a distance according to elapsed time of severe condition to the travel distance when the driving state of the engine is in severe condition to perform the correction such that the travel distance when the driving state of the engine is in the severe condition is larger than an actual travel distance.
Further, in the example of the FIG. 7, the weighted coefficient is set to "2" when the elapsed time of the severe condition is long. However, the weighted coefficient may be increased exponentially according to the elapsed time of the severe condition. This makes it possible to perform the correction such that the corrected driving distance is increased as the elapsed time of the severe condition increases.
Also in the case where the driving state of the engine is determined based on water temperature of engine cooling fluid, engine RPM(revolutions per minute) of the engine, intake manifold pressure, boost pressure, air intake quantity, throttle position, or accelerator position of vehicle 2, correction of the travel distance is performed similarly. In other words, travel distance correction part 23 multiplies the travel distance when the driving state of the engine is in severe condition by the weighted coefficient according to the elapsed time of the severe condition to perform the correction such that the travel distance when the driving state of the engine is in the severe condition is larger than an actual travel distance. Alternatively, travel distance correction part 23 may add a distance according to elapsed time of severe condition to the travel distance when the driving state of the engine is in severe condition to perform the correction such that the travel distance when the driving state of the engine is in the severe condition is larger than an actual travel distance. For instance, like the example of FIG. 3, in the case where the driving state of the engine is determined based on water temperature of engine cooling fluid, the weighted coefficients during high load time intervals of T1 to T4 and high load time intervals of T5 to T7 are set to 2, and a weighted coefficient during an interval other than the above-mentioned high load time intervals may be set to 1. Further, instead of the travel distance when the driving state of the engine is in severe condition, a total travel distance during the engine state determination period (i.e., including not only the travel distance when the driving state of an engine is in severe condition but the travel distance when the driving state of an engine is in usual condition) may be employed. In other words, not only during the high load time interval but over the entire engine state determination period, the driving state of the engine is determined and the weighted coefficient is calculated. Thus, the total travel distance during the engine state determination period may be multiplied by the weighted coefficient.
In the case where the driving state of the engine is determined based on low-speed driving time or idling time of vehicle 2, travel distance correction part 23 multiplies the total travel distance during the engine state determination period (e.g., one driving cycle) by a weighted coefficient set in advance to perform the correction such that the total travel distance is larger than an actual travel distance. Specifically, travel distance correction part 23 performs such correction that the travel distance at every vehicle information acquisition period is multiplied by a weighted coefficient of more than 1, which is changed according to the engine state information during the vehicle information acquisition period. Travel distance correction part 23 calculates the sum of travel distances, after the correction, during the engine state determination period to obtain a corrected driving distance. Further, the weighted coefficient according to a ratio of a period of low-speed driving time or idling time to the engine state determination period may be employed. In this case, the ratio of the period of low-speed driving time or idling time to the engine state determination period is detected by engine state determination part 22. A total travel distance is multiplied by the weighted coefficient according to the ratio of a period of low-speed driving time or idling time to the engine state determination period, or a distance according to the weighted coefficient is added to the total travel distance to perform the correction such that the total travel distance is larger than an actual travel distance.
Likewise, in the case where the driving state of the engine is determined based on a total travel distance during engine state determination period, travel distance correction part 23 multiplies the total travel distance during engine state determination period (e.g., one driving cycle) by a weighted coefficient set in advance to perform the correction such that the total travel distance is larger than an actual travel distance. Alternatively, travel distance correction part 23 may use a weighted coefficient according to the total travel distance to perform the correction such that the total travel distance is larger than an actual travel distance.
Further, when the driving state of the engine is in severe condition, travel distance correction part 23 may change a weighted coefficient according to a degree of the severe condition of the engine. In this case, the degree of the severe condition is detected by engine state determination part 22. For instance, in the case where the driving state of the engine is determined based on oil temperature of engine oil, when the oil temperature of engine oil exceeds 120°C, the degree of the severe condition may be determined to be "level 1", and when the oil temperature exceeds 140°C, the degree of the severe condition may be determined to be "level 2." Travel distance correction part 23 may change a weighted coefficient according to the degree of the severe condition. For instance, when the degree of the severe condition is "level 1," the weighted coefficient may be set to 1.1 to 2, and when the degree of severe condition is "level 2," the weighted coefficient may be set to 2.1 to 3.
By doing so, based on the travel distance of vehicle 2 and the engine state information that is inputted from vehicle information acquisition part 21 and engine state determination part 22, travel distance correction part 23 can correct the total travel distance during the engine state determination period set in advance to calculate a corrected driving distance. The corrected driving distance calculated by travel distance correction part 23 is inputted to oil remaining life calculation part 24.
Oil remaining life calculation part 24 subtracts the corrected driving distance, which is calculated by travel distance correction part 23, from the residual remaining distance stored in oil remaining life storage part 25 to calculate a new residual remaining distance. As mentioned above, the corrected driving distance is corrected according to the driving state of the engine. In other words, the travel distance when the driving state of the engine is in severe condition is corrected to be larger than an actual travel distance. This makes it possible to detect a remaining life of engine oil in consideration of the driving state of the engine, by subtracting the corrected driving distance from the residual remaining distance. The new residual remaining distance calculated by oil remaining life calculation part 24 is inputted to oil remaining life storage part 25 and stored therein. In other words, the residual remaining distance is updated. Further, the new residual remaining distance calculated by oil remaining life calculation part 24 is inputted to oil change determination part 26.
Oil remaining life storage part 25 stores the residual remaining distance serving as an oil remaining life. First, when replacing engine oil, a user sets an initial value of the residual remaining distance through input means (not shown). The initial value of the residual remaining distance is a remaining distance when the driving state of the engine is in usual condition. The initial value of the residual remaining distance is changed depending on kinds of engine oil (i.e., oil viscosity and a oil grade), volume of engine oil, and vehicle types (or engine types). Note that, for the initial value of the residual remaining distance, a user may input directly, or oil remaining life detection device 1 may set automatically based on information relating to engine oil and vehicle 2, which is inputted from a user.
Oil change determination part 26 determines time to oil exchange engine oil based on the new residual remaining distance calculated by oil remaining life calculation part 24. For instance, when the residual remaining distance is 300 km or more, it is determined that the residual remaining distance, serving as an oil remaining life, remains still enough. Thus, oil change determination part 26 determines that "replacement is not necessary." When the residual remaining distance is less than 300 km and more than or equal to 100 km, it is determined that time to oil exchange engine oil grows nearer. Thus, oil change determination part 26 determines that "time to oil exchange grows nearer." When the residual remaining distance is less than 100 km, it is determined that time to oil exchange engine oil has come. Thus, oil change determination part 26 determines that "time to oil exchange has come."
Further, engine oil aging due to oxidization caused by contact with air, or the like. Thus, the time to oil exchange engine oil may be determined in consideration of driving time of the engine oil. Furthermore, severe travel condition, such as a circuit running, makes the driving state of the engine still severer, for example. Accordingly, the time to oil exchange engine oil may be determined in consideration of frequency, time, and a travel distance of such severe travel condition.
In the above-mentioned exemplary embodiment, as the oil remaining life detection process of engine oil, it has been described that the vehicle information acquisition process is carried out during the engine state determination period, and other processes are carried out one by one after the engine state determination period. In other words, it has been described that the residual remaining distance is updated at every engine state determination period. As the oil remaining life detection process of engine oil, each process during the vehicle information acquisition period, i.e., acquisition of vehicle information, determination of the driving state of the engine, calculation of a corrected driving distance, calculation of a residual remaining distance, and determination of time to oil exchange oil may be carried out at every vehicle information acquisition period. For instance, with respect to the travel distance at every vehicle information acquisition period, travel distance correction part 23 makes correction according to the engine state information during the vehicle information acquisition period. Oil remaining life calculation part 24 subtracts the corrected driving distance, which is calculated by travel distance correction part 23, from the residual remaining distance to calculate a new residual remaining distance. The above processes are carried out at every vehicle information acquisition period during the engine state determination period.
Further, in agreement with the passage of real time while vehicle 2 is running, the above-mentioned process may be carried out at every vehicle information acquisition period. For instance, in the case where the driving state of the engine is determined in agreement with the passage of real time at every vehicle information acquisition period, the processes of step ST204 and step ST210 shown in FIG. 4 may be caused to wait until the next vehicle information acquisition period as time elapses. When the next vehicle information acquisition period has come, vehicle information acquisition part 21 may acquire the vehicle information.
As mentioned above, in the present exemplary embodiment, oil remaining life detection device 1, which detects a remaining life of engine oil of vehicle 2, includes: vehicle information acquisition part 21 that acquires, from vehicle 2, information relating to a travel distance of vehicle 2 and information relating to an driving state of an engine of vehicle 2 at every vehicle information acquisition period set in advance; engine state determination part 22 that determines the driving state of the engine during an engine state determination period set in advance, based on the information relating to the driving state of the engine; travel distance correction part 23 that corrects the travel distance of vehicle 2 during the engine state determination period according to the driving state of the engine to calculate a corrected driving distance; and oil remaining life calculation part 24 that subtracts the corrected driving distance from a residual remaining distance, which indicates the remaining life of engine oil, to calculate a new residual remaining distance.
By doing so, the total travel distance during the engine state determination period can be corrected according to the driving state of the engine. This makes it possible to detect a remaining life of engine oil, in consideration of the driving state of the engine, based on the vehicle information acquired from vehicle 2.
Further, oil remaining life detection device 1 includes oil change determination part 26 that determines time to oil exchange engine oil based on the residual remaining distance.
This makes it possible to determine the time to oil exchange engine oil based on the new residual remaining distance calculated by oil remaining life calculation part 24, for example, by comparing the new residual remaining distance with a predetermined threshold.
Further, engine state determination part 22 determines whether or not the driving state of the engine is in severe condition. When the driving state of the engine is determined to be in severe condition, engine state determination part 22 detects elapsed time or frequency of occurrence of the severe condition. When the driving state of the engine is determined to be in the severe condition, travel distance correction part 23 performs the correction such that the total travel distance during the engine state determination period is larger than an actual travel distance, according to the elapsed time or the frequency of occurrence of the severe condition.
This makes it possible to correct the residual remaining distance until engine oil is replaced, according to the elapsed time or the frequency of occurrence of the severe condition.
Further, when the driving state of the engine is determined to be in severe condition, engine state determination part 22 sets a protection time interval with a predetermined length after the severe condition ends. When the severe condition is detected again in the protection time interval, the severe condition of the engine is deemed to be continued.
This makes it possible to detect a remaining life of engine oil in consideration of the case where the usual condition and the severe condition are repeated and the severe condition is deemed to be continued substantially.
Further, engine state determination part 22 determines whether or not the driving state of the engine is in severe condition. When the driving state of the engine is determined to be in severe condition, engine state determination part 22 examines a degree of the severe condition. When the driving state of the engine is determined to be in severe condition, travel distance correction part 23 performs the correction, according to the degree of the severe condition, such that the total travel distance during the engine state determination period is larger than an actual travel distance.
This makes it possible to correct the residual remaining distance until engine oil is replaced, according to the degree of the severe condition.
Further, travel distance correction part 23 corrects the total travel distance during the engine state determination period using a weighted coefficient that is set according to the driving state of the engine.
This makes it possible to correct the total travel distance during the engine state determination period easily.
Further, travel distance correction part 23 corrects the total travel distance during the engine state determination period using a weighted coefficient that is set according to the driving state of the engine and elapsed time or frequency of occurrence of the severe condition.
This makes it possible to correct the total travel distance during the engine state determination period easily and appropriately.
Further, travel distance correction part 23 corrects the total travel distance during the engine state determination period using a weighted coefficient that is set according to the driving state of the engine and a degree of the severe condition.
This makes it possible to correct the total travel distance during the engine state determination period easily and appropriately.
Further, the information relating to the driving state of the engine of vehicle 2 includes oil temperature of engine oil or water temperature of engine cooling fluid of vehicle 2. When the oil temperature of engine oil or the water temperature of engine cooling fluid exceeds a value set in advance, the driving state of the engine is determined to be in severe condition.
This makes it possible to determine the driving state of the engine simply and easily.
Further, the information relating to the driving state of the engine of vehicle 2 is at least one of engine RPM(revolutions per minute) of the engine, intake manifold pressure, boost pressure, air intake quantity, throttle position, or accelerator position of vehicle 2. When the revolution speed of the engine, the intake manifold pressure, the boost pressure, the air intake quantity, the throttle position, or the accelerator position of vehicle 2 exceeds a value set in advance, engine state determination part 22 determines that the driving state of the engine is in severe condition.
This makes it possible to determine the driving state of the engine simply and easily.
Further, the information relating to the driving state of the engine of vehicle 2 includes low-speed driving time or idling time of vehicle 2 in the engine state determination period. When a ratio of a period of low-speed driving time or idling time to the engine state determination period exceeds a value set in advance, engine state determination part 22 determines that the driving state of the engine is in severe condition.
This makes it possible to determine the driving state of the engine simply and easily.
Further, the information relating to the driving state of the engine of vehicle 2 includes the total travel distance during the engine state determination period. When the total travel distance during the engine state determination period is less than a value set in advance, engine state determination part 22 determines that the driving state of the engine is in severe condition.
This makes it possible to determine the driving state of the engine simply and easily.
As mentioned above, the present disclosure has been described based on specified exemplary embodiments, but theses exemplary embodiments are merely illustrative and do not intend to limit the present disclosure. Note that, for each of components of the oil remaining life calculation device and the oil remaining life calculation method in accordance with the present disclosure described in the above-mentioned exemplary embodiments, all of the components are not necessarily essential and can be selected as necessary, without departing from at least the scope of the present disclosure.

INDUSTRIAL APPLICABILITY

The present disclosure is applicable to an oil remaining life calculation device for detecting a remaining life of engine oil based on vehicle information acquired from a vehicle, and an oil remaining life calculation method. Specifically, the present disclosure is useful as an oil remaining life calculation device and an oil remaining life calculation method that make it possible to detect a remaining life of engine oil, in consideration of an driving state of an engine, based on vehicle information acquired from on-board information detection systems such as an on-board diagnostic system.

REFERENCE MARKS IN THE DRAWINGS

1: oil remaining life detection device
2: vehicle
11: ECU
12: connector part
20: CPU
21: vehicle information acquisition part
22: engine state determination part
23: travel distance correction part
24: oil remaining life calculation part
25: oil remaining life storage part
26: oil change determination part
30: memory

Claims

An oil remaining life calculation device for detecting a remaining life of engine oil of a vehicle, the oil remaining life calculation device comprising:
a vehicle information acquisition part that acquires, from the vehicle, information relating to a travel distance of the vehicle and information relating to an driving state of an engine of the vehicle at every vehicle information acquisition period set in advance;

an engine state determination part that determines the driving state of the engine during an engine state determination period set in advance, based on the information relating to the driving state of the engine;

a travel distance correction part that corrects the travel distance of the vehicle during the engine state determination period according to the driving state of the engine to calculate a corrected driving distance; and

an oil remaining life calculation part that subtracts the corrected driving distance from a residual remaining distance indicating the remaining life of the engine oil to calculate a new residual remaining distance.
The oil remaining life calculation device according to claim 1, further comprising
an oil change determination part that determines time to oil exchange the engine oil based on the residual remaining distance.
The oil remaining life calculation device according to claim 1, wherein:
the engine state determination part determines whether or not the driving state of the engine is in severe condition, and detects elapsed time or frequency of occurrence of the severe condition when determining that the driving state of the engine is in the severe condition; and

when the driving state of the engine is determined to be in the severe condition, the travel distance correction part performs the correction such that a total travel distance during the engine state determination period is larger than an actual travel distance, according to the elapsed time or the frequency of occurrence of the severe condition.
The oil remaining life calculation device according to claim 3, wherein
when the driving state of the engine is determined to be in the severe condition, the engine state determination part sets a protection time interval with a predetermined length after the severe condition ends, and

when the severe condition of the engine is detected again during the protection time interval, the engine state determination part determines that the severe condition of the engine continues.
The oil remaining life calculation device according to claim 1, wherein:
the engine state determination part determines whether or not the driving state of the engine is in severe condition, and examines a degree of the severe condition when determining that the driving state of the engine is in the severe condition; and

when the driving state of the engine is determined to be in the severe condition, the travel distance correction part performs the correction such that a total travel distance during the engine state determination period is larger than an actual travel distance, according to the degree of the severe condition.
The oil remaining life calculation device according to claim 1, wherein
the travel distance correction part uses a weighted coefficient that is set according to the driving state of the engine to correct a total travel distance during the engine state determination period.
The oil remaining life calculation device according to claim 3, wherein
the travel distance correction part uses a weighted coefficient that is set according to the driving state of the engine and the elapsed time or the frequency of occurrence of the sever condition to correct the total travel distance during the engine state determination period.
The oil remaining life calculation device according to claim 5, wherein
the travel distance correction part uses a weighted coefficient that is set according to the driving state of the engine and the degree of the severe condition to correct the total travel distance during the engine state determination period.
The oil remaining life calculation device according to claim 3, wherein
the information relating to the driving state of the engine of the vehicle includes oil temperature of the engine oil or water temperature of engine cooling fluid of the vehicle, and

when the oil temperature of the engine oil or the water temperature of the engine cooling fluid exceeds a value set in advance, the engine state determination part determines that the driving state of the engine is in the severe condition.
The oil remaining life calculation device according to claim 3, wherein
the information relating to the driving state of the engine of the vehicle includes at least one of engine revolutions per minute of the engine, intake manifold pressure, boost pressure, air intake quantity, throttle position, or accelerator position of the vehicle, and

when the at least one of engine revolutions per minute of the engine, intake manifold pressure, boost pressure, air intake quantity, throttle position, or accelerator position of the vehicle exceeds a value set in advance, the engine state determination part determines that the driving state of the engine is in the severe condition.
The oil remaining life calculation device according to claim 3, wherein
the information relating to the driving state of the engine of the vehicle includes low-speed driving time or idling time of the vehicle in the engine state determination period, and

when a ratio of the low-speed driving time or the idling time to the engine state determination period exceeds a value set in advance, the engine state determination part determines that the driving state of the engine is in the severe condition.
The oil remaining life calculation device according to claim 3, wherein
the information relating to the driving state of the engine of the vehicle includes the total travel distance during the engine state determination period, and

when the total travel distance during the engine state determination period is less than a value set in advance, the engine state determination part determines that the driving state of the engine is in the severe condition.
The oil remaining life calculation device according to claim 5, wherein
the information relating to the driving state of the engine of the vehicle includes oil temperature of the engine oil or water temperature of engine cooling fluid of the vehicle, and

when the oil temperature of the engine oil or the water temperature of the engine cooling fluid exceeds a value set in advance, the engine state determination part determines that the driving state of the engine is in the severe condition.
The oil remaining life calculation device according to claim 5, wherein
the information relating to the driving state of the engine of the vehicle includes at least one of engine revolutions per minute of the engine, intake manifold pressure, boost pressure, air intake quantity, throttle position, or accelerator position of the vehicle, and

when the at least one of engine revolutions per minute of the engine, intake manifold pressure, boost pressure, air intake quantity, throttle position, or accelerator position of the vehicle exceeds a value set in advance, the engine state determination part determines that the driving state of the engine is in the severe condition.
The oil remaining life calculation device according to claim 5, wherein
the information relating to the driving state of the engine of the vehicle includes low-speed driving time or idling time of the vehicle in the engine state determination period, and

when a ratio of the low-speed driving time or the idling time to the engine state determination period exceeds a value set in advance, the engine state determination part determines that the driving state of the engine is in the severe condition.
The oil remaining life calculation device according to claim 5, wherein
the information relating to the driving state of the engine of the vehicle includes the total travel distance during the engine state determination period, and

when the total travel distance during the engine state determination period is less than a value set in advance, the engine state determination part determines that the driving state of the engine is in the severe condition.
An oil remaining life calculation method for detecting a remaining life of engine oil of a vehicle, the oil remaining life calculation method comprising the steps of:
acquiring, from the vehicle, information relating to a travel distance of the vehicle and information relating to an driving state of an engine of the vehicle at every vehicle information acquisition period set in advance;

determining whether the driving state of the engine during an engine state determination period set in advance is in usual condition or in severe condition, based on the information relating to the driving state of the engine;

correcting and accumulating the travel distance of the vehicle during the engine state determination period according to the driving state of the engine to calculate a corrected driving distance;

subtracting the corrected driving distance from a residual remaining distance indicating the remaining life of the engine oil to calculate a new residual remaining distance; and

storing the new residual remaining distance.