阅读说明：本技术 一种车辆机油粘度实时预测方法及装置 (Method and device for predicting viscosity of vehicle engine oil in real time ) 是由 陈秀 马蜀超 余亮 周祥军 于 2020-12-24 设计创作，主要内容包括：本申请涉及一种车辆机油粘度实时预测方法及装置,涉及汽车技术领域,该方法包括以下步骤：根据发动机额定功率下的第一机油压力、第一摩擦扭矩以及第一发动机曲轴转速,结合发动机曲轴直径以及机油初始粘度,计算获得机油粘度关系系数；根据监测获得发动机当前功率下的当前机油压力、当前摩擦扭矩以及发动机曲轴转速,结合发动机曲轴直径以及机油粘度关系系数,计算获得发动机当前功率下的当前机油粘度。本申请对机油情况进行实施监测,并结合车辆的多项因素综合评估,对车辆机油粘度进行合理预测,具有成本低、操作便利以及准确度高的优势。(The application relates to a method and a device for predicting viscosity of vehicle engine oil in real time, which relate to the technical field of automobiles, and the method comprises the following steps: calculating to obtain an engine oil viscosity relation coefficient according to the first engine oil pressure, the first friction torque and the first engine crankshaft rotating speed under the rated power of the engine and by combining the engine crankshaft diameter and the initial engine oil viscosity; and calculating to obtain the current engine oil viscosity under the current power of the engine by combining the diameter of the engine crankshaft and the engine oil viscosity relation coefficient according to the current engine oil pressure, the current friction torque and the engine crankshaft rotating speed under the current power of the engine obtained by monitoring. The engine oil condition is monitored, comprehensive evaluation is conducted on multiple factors of the vehicle, the viscosity of the engine oil of the vehicle is reasonably predicted, and the engine oil condition monitoring system has the advantages of being low in cost, convenient to operate and high in accuracy.)

1. A method for predicting viscosity of vehicle engine oil in real time, which is characterized by comprising the following steps:

calculating to obtain an engine oil viscosity relation coefficient according to the first engine oil pressure, the first friction torque and the first engine crankshaft rotating speed under the rated power of the engine and by combining the engine crankshaft diameter and the initial engine oil viscosity;

and calculating to obtain the current oil viscosity of the engine under the current power by combining the diameter of the engine crankshaft and the oil viscosity relation coefficient according to the current oil pressure, the current friction torque and the engine crankshaft rotating speed which are obtained under the current power of the engine through monitoring.

2. The method of real-time prediction of vehicle oil viscosity of claim 1, wherein the method is based on a custom oil viscosity calculation formula, the custom oil viscosity calculation formula being:

wherein the content of the first and second substances,

eta is the viscosity of the engine oil, k is the coefficient of the relationship between the viscosity of the engine oil, p_{Oil pressure}For oil pressure, T_{Friction of}D is the diameter of an output shaft of the engine, and n is the rotating speed of a crankshaft of the engine.

3. The method for real-time prediction of vehicle oil viscosity according to claim 1, further comprising the steps of:

according to a preset period, calculating a current viscosity ratio between the current engine oil viscosity and the initial engine oil viscosity;

and comparing the current viscosity ratio with an upper viscosity ratio value and a lower viscosity ratio value, and giving an engine oil viscosity alarm if the current viscosity ratio is not between the upper viscosity ratio value and the lower viscosity ratio value.

4. The method for predicting viscosity of vehicle oil in real time according to claim 2, wherein the step of calculating the oil viscosity relation coefficient according to the first oil pressure, the first friction torque and the first engine crankshaft speed under the rated power of the engine and combining the engine crankshaft diameter and the initial viscosity of the oil comprises the following steps:

obtaining a first engine oil pressure, a first friction torque and a first engine crankshaft rotating speed under the rated power of an engine;

obtaining the initial viscosity of the engine oil according to the model of the engine oil;

and substituting the first engine oil pressure, the first friction torque and the first engine crankshaft rotating speed into the user-defined engine oil viscosity calculation formula by combining the engine crankshaft diameter and the engine oil initial viscosity, and calculating to obtain the engine oil viscosity relation coefficient.

5. The method for predicting the viscosity of the vehicle oil in real time according to claim 2, wherein the step of calculating the current viscosity of the vehicle oil at the current power of the engine according to the current oil pressure, the current friction torque and the engine crankshaft speed at the current power of the engine obtained by monitoring and the engine crankshaft diameter and the oil viscosity relation coefficient comprises the following steps:

monitoring and obtaining the current engine oil pressure, the current friction torque and the engine crankshaft rotating speed under the current power of the engine;

obtaining the diameter of the engine crankshaft and the viscosity relation coefficient of the engine oil;

and substituting the current engine oil pressure, the current friction torque and the engine crankshaft rotating speed into the custom engine oil viscosity calculation formula by combining the engine crankshaft diameter and the engine oil viscosity relation coefficient, and calculating to obtain the current engine oil viscosity under the current power of the engine.

6. A vehicle oil viscosity real-time prediction apparatus, characterized in that the apparatus comprises:

the monitoring unit is used for detecting and obtaining first engine oil pressure, first friction torque and first engine crankshaft rotating speed under the rated power of the engine and is also used for monitoring and obtaining current engine oil pressure, current friction torque and engine crankshaft rotating speed under the current power of the engine;

the viscosity relation coefficient calculation unit is used for calculating and obtaining an oil viscosity relation coefficient according to the first oil pressure, the first friction torque and the first engine crankshaft rotating speed by combining the engine crankshaft diameter and the initial oil viscosity;

and the oil viscosity calculating unit is used for calculating and obtaining the current oil viscosity under the current power of the engine according to the current oil pressure, the current friction torque and the engine crankshaft rotating speed by combining the diameter of the engine crankshaft and the oil viscosity relation coefficient.

7. The vehicle oil viscosity real-time prediction device of claim 6, wherein the device is based on a custom oil viscosity calculation formula, the custom oil viscosity calculation formula being:

wherein the content of the first and second substances,

eta is the viscosity of the engine oil, k is the coefficient of the relationship between the viscosity of the engine oil, p_{Oil pressure}For oil pressure, T_{Friction of}D is the diameter of an output shaft of the engine, and n is the rotating speed of a crankshaft of the engine.

8. The vehicle oil viscosity real-time prediction apparatus of claim 6, further comprising an oil type analysis unit for obtaining an initial oil viscosity based on the oil type.

9. The vehicle oil viscosity real-time prediction apparatus of claim 6, further comprising a viscosity ratio calculation unit for calculating a current viscosity ratio between the current oil viscosity and the initial oil viscosity according to a preset period.

10. The vehicle oil viscosity real-time prediction device of claim 9, further comprising a viscosity alarm unit for comparing the current viscosity ratio value to a viscosity ratio threshold value and providing an oil viscosity alarm if the current viscosity ratio value is not between the upper viscosity ratio value limit and the lower viscosity ratio value limit.

Technical Field

The invention relates to the technical field of automobiles, in particular to a method and a device for predicting viscosity of vehicle engine oil in real time.

Background

At the present stage, in order to ensure that the engine can normally perform daily work, the engine oil needs to be replaced regularly, and during the engine oil replacement work, the engine oil viscosity needs to be predicted, and the engine oil viscosity prediction generally adopts the following method:

the engine oil replacement mileage or time is determined according to specific limit working conditions, but the service time and mileage accumulation curves of the same engine type and different configurations or the same configuration under different working conditions are different. The viscosity of the oil determined in terms of a single specific limit condition therefore varies over a large portion of the vehicle. In addition, under certain very harsh operating conditions or poor driving behavior, the viscosity of the oil may be significantly different from the viscosity of the oil determined for the particular extreme operating condition.

The viscosity of the engine oil is calculated through a single factor, but the mode takes the single factor into consideration, and the prediction accuracy is poor.

Therefore, the method for predicting the viscosity of the automobile engine oil, which is convenient to operate, high in accuracy and low in implementation cost, is lacked at present.

Disclosure of Invention

The application provides a method and a device for predicting the viscosity of vehicle engine oil in real time, which are used for monitoring the condition of the engine oil, comprehensively evaluating multiple factors of a vehicle and reasonably predicting the viscosity of the vehicle engine oil, and have the advantages of low cost, convenience in operation and high accuracy.

In a first aspect, the present application provides a method for predicting viscosity of vehicle oil in real time, the method comprising the steps of:

calculating to obtain an engine oil viscosity relation coefficient according to the first engine oil pressure, the first friction torque and the first engine crankshaft rotating speed under the rated power of the engine and by combining the engine crankshaft diameter and the initial engine oil viscosity;

and calculating to obtain the current oil viscosity of the engine under the current power by combining the diameter of the engine crankshaft and the oil viscosity relation coefficient according to the current oil pressure, the current friction torque and the engine crankshaft rotating speed which are obtained under the current power of the engine through monitoring.

Specifically, the method is based on a custom oil viscosity calculation formula, which is as follows:

wherein the content of the first and second substances,

eta is the viscosity of the engine oil, k is the coefficient of the relationship between the viscosity of the engine oil, p_{Oil pressure}For oil pressure, T_{Friction of}D is the diameter of an output shaft of the engine, and n is the rotating speed of a crankshaft of the engine.

Further, the method comprises the following steps:

according to a preset period, calculating a current viscosity ratio between the current engine oil viscosity and the initial engine oil viscosity;

and comparing the current viscosity ratio with an upper viscosity ratio value and a lower viscosity ratio value, and giving an engine oil viscosity alarm if the current viscosity ratio is not between the upper viscosity ratio value and the lower viscosity ratio value.

Specifically, the step of calculating the engine oil viscosity relation coefficient according to the first engine oil pressure, the first friction torque and the first engine crankshaft rotation speed under the rated power of the engine and by combining the engine crankshaft diameter and the initial engine oil viscosity includes the following steps:

obtaining a first engine oil pressure, a first friction torque and a first engine crankshaft rotating speed under the rated power of an engine;

obtaining the initial viscosity of the engine oil according to the model of the engine oil;

and substituting the first engine oil pressure, the first friction torque and the first engine crankshaft rotating speed into the user-defined engine oil viscosity calculation formula by combining the engine crankshaft diameter and the engine oil initial viscosity, and calculating to obtain the engine oil viscosity relation coefficient.

Specifically, the step of calculating and obtaining the current oil viscosity of the engine under the current power by combining the diameter of the engine crankshaft and the oil viscosity relation coefficient according to the current oil pressure, the current friction torque and the engine crankshaft rotating speed under the current power of the engine obtained by monitoring comprises the following steps:

monitoring and obtaining the current engine oil pressure, the current friction torque and the engine crankshaft rotating speed under the current power of the engine;

obtaining the diameter of the engine crankshaft and the viscosity relation coefficient of the engine oil;

and substituting the current engine oil pressure, the current friction torque and the engine crankshaft rotating speed into the custom engine oil viscosity calculation formula by combining the engine crankshaft diameter and the engine oil viscosity relation coefficient, and calculating to obtain the current engine oil viscosity under the current power of the engine.

In a second aspect, the present application provides a vehicle oil viscosity real-time prediction device, comprising:

the monitoring unit is used for detecting and obtaining first engine oil pressure, first friction torque and first engine crankshaft rotating speed under the rated power of the engine and is also used for monitoring and obtaining current engine oil pressure, current friction torque and engine crankshaft rotating speed under the current power of the engine;

the viscosity relation coefficient calculation unit is used for calculating and obtaining an oil viscosity relation coefficient according to the first oil pressure, the first friction torque and the first engine crankshaft rotating speed by combining the engine crankshaft diameter and the initial oil viscosity;

and the oil viscosity calculating unit is used for calculating and obtaining the current oil viscosity under the current power of the engine according to the current oil pressure, the current friction torque and the engine crankshaft rotating speed by combining the diameter of the engine crankshaft and the oil viscosity relation coefficient.

Specifically, the device is based on a custom oil viscosity calculation formula, which is as follows:

wherein the content of the first and second substances,

eta is the viscosity of the engine oil, k is the coefficient of the relationship between the viscosity of the engine oil, p_{Oil pressure}For oil pressure, T_{Friction of}D is the diameter of an output shaft of the engine, and n is the rotating speed of a crankshaft of the engine.

Further, the device also comprises an engine oil type analyzing unit which is used for obtaining the initial viscosity of the engine oil according to the engine oil type.

Further, the device further comprises a viscosity ratio calculation unit, which is used for calculating the current viscosity ratio between the current oil viscosity and the initial oil viscosity according to a preset period.

Further, the device further comprises a viscosity alarm unit, which is used for comparing the current viscosity ratio with an upper viscosity ratio value and a lower viscosity ratio value, and carrying out oil viscosity alarm if the current viscosity ratio is not between the upper viscosity ratio value and the lower viscosity ratio value.

The beneficial effect that technical scheme that this application provided brought includes:

the engine oil condition is monitored, comprehensive evaluation is conducted on multiple factors of the vehicle, the viscosity of the engine oil of the vehicle is reasonably predicted, and the engine oil condition monitoring system has the advantages of being low in cost, convenient to operate and high in accuracy.

Drawings

In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the description of the embodiments are briefly introduced below, and it is obvious that the drawings in the following description are only some embodiments of the present application, and it is obvious for those skilled in the art to obtain other drawings based on these drawings without creative efforts.

FIG. 1 is a flow chart illustrating steps of a method for predicting viscosity of vehicle oil in real time according to an embodiment of the present disclosure;

FIG. 2 is a schematic hardware block diagram of a method for predicting viscosity of vehicle oil in real time according to an embodiment of the present disclosure;

FIG. 3 is a block diagram illustrating a structure of a device for predicting viscosity of vehicle oil in real time according to an embodiment of the present disclosure.

Detailed Description

Interpretation of terms:

CAN Bus, Controller Area network-work Bus, serial Bus system;

sensors, Sensors;

GPS, Global Positioning System;

storm, a distributed real-time big data processing framework;

redis, Remote Dictionary Server, i.e., Remote Dictionary service;

spark, a general parallel framework like Hadoop MapReduce;

HBase, a distributed, column-oriented open source database;

HDFS, Hadoop Distributed File System, Distributed File System;

hive, a data warehouse tool based on Hadoop;

presto, a distributed SQL query engine;

PDM, Product Data Management;

CRM, Customer Relationship Management;

ECU, Electronic Control Unit.

In order to make the objects, technical solutions and advantages of the embodiments of the present application clearer, the technical solutions in the embodiments of the present application will be clearly and completely described below with reference to the drawings in the embodiments of the present application, and it is obvious that the described embodiments are some embodiments of the present application, but not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments given herein without making any creative effort, shall fall within the protection scope of the present application.

Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

The embodiment of the invention provides a method and a device for predicting the viscosity of vehicle engine oil in real time, which are used for monitoring the condition of the engine oil, reasonably predicting the viscosity of the vehicle engine oil by combining multiple factors of a vehicle, and have the advantages of low cost, convenience in operation and high accuracy.

In order to achieve the technical effects, the general idea of the application is as follows:

a method for predicting viscosity of vehicle engine oil in real time comprises the following steps:

s1, calculating and obtaining an engine oil viscosity relation coefficient according to the first engine oil pressure, the first friction torque and the first engine crankshaft rotating speed under the rated power of the engine and by combining the engine crankshaft diameter and the initial engine oil viscosity;

and S2, obtaining the current oil pressure, the current friction torque and the engine crankshaft speed under the current power of the engine according to monitoring, and calculating to obtain the current oil viscosity under the current power of the engine by combining the engine crankshaft diameter and the oil viscosity relation coefficient.

Embodiments of the present invention will be described in further detail below with reference to the accompanying drawings.

In a first aspect, referring to fig. 1 and 2, an embodiment of the present invention provides a method for predicting viscosity of vehicle oil in real time, including the following steps:

s1, calculating and obtaining an engine oil viscosity relation coefficient according to the first engine oil pressure, the first friction torque and the first engine crankshaft rotating speed under the rated power of the engine and by combining the engine crankshaft diameter and the initial engine oil viscosity;

and S2, obtaining the current oil pressure, the current friction torque and the engine crankshaft speed under the current power of the engine according to monitoring, and calculating to obtain the current oil viscosity under the current power of the engine by combining the engine crankshaft diameter and the oil viscosity relation coefficient.

In the embodiment of the application, the engine oil condition is monitored, the comprehensive evaluation of multiple factors of a vehicle is combined, the viscosity of the engine oil of the vehicle is reasonably predicted, and the engine oil monitoring system has the advantages of low cost, convenience in operation and high accuracy.

Further, the method comprises the following steps:

s3, according to a preset period, calculating a current viscosity ratio between the current engine oil viscosity and the initial engine oil viscosity;

and S4, comparing the current viscosity ratio with the upper limit value and the lower limit value of the viscosity ratio, and giving an engine oil viscosity alarm if the current viscosity ratio is not between the upper limit value and the lower limit value of the viscosity ratio.

It should be noted that the viscosity of the engine oil is an important index of the performance and the service life of the engine oil, and the viscosity characteristic of the engine oil is selected according to different configurations of the vehicle and actual operating conditions of the vehicle;

the oil is wasted due to excessive viscosity, the economical efficiency is poor, the viscosity is too low, and the lubrication is insufficient, so that the part abrasion is caused, and the service life of parts is reduced;

through the engine oil viscosity alarm, a driver can be informed to replace the engine oil in time, so that the waste of fuel oil and the abrasion of parts are avoided.

Specifically, the method is based on a custom oil viscosity calculation formula, which is as follows:

wherein the content of the first and second substances,

eta is the viscosity of the engine oil, k is the coefficient of the relationship between the viscosity of the engine oil, p_{Oil pressure}For oil pressure, T_{Friction of}D is the diameter of an output shaft of the engine, and n is the rotating speed of a crankshaft of the engine.

It should be noted that, according to the Stribeck curve, the comprehensive influence of the factors such as the viscosity, the rotating speed, the oil film thickness and the working pressure of the part of the lubricating oil on the friction factor f under different lubricating states can be clearly analyzed, and the formula is as follows:

in the formula (1), D is the diameter of the rotating shaft of the part, i.e., the diameter of the output shaft of the engine, h is the thickness of the oil film, η is the viscosity of the lubricating oil, n is the rotational speed of the crankshaft of the engine, Load is the pressure to which the part is subjected, and f is the coefficient of friction.

The oil film thickness is dependent on the oil pressure, i.e. h ═ kp_{Oil pressure}，p_{Oil pressure}Representing the oil pressure, and k is a coefficient of relationship.

Because the friction coefficient is equal to the ratio of friction torque to part bearing pressure, the formula (1) can be rewritten to obtain a new oil viscosity calculation method, namely, a custom oil viscosity calculation formula:

calculating k value, and searching the initial viscosity eta of the engine oil in an engine oil physicochemical database according to the brand information of the vehicle and the engine oil added to the vehicle₀And then obtaining the oil pressure and the friction torque, using the oil pressure and the friction torque under the rated power, substituting the values into the formula (2) to calculate the k value.

According to a preset calculation period, regularly calculating and calculating the viscosity value of the engine oil, calculating the viscosity value of the engine oil of each vehicle according to a formula (2), and further comparing the viscosity value with the initial viscosity to obtain the current viscosity ratio, namely

Specifically, in step S1, the step of obtaining the engine oil viscosity relation coefficient by calculation according to the first engine oil pressure, the first friction torque and the first engine crankshaft speed at the engine rated power, in combination with the engine crankshaft diameter and the initial engine oil viscosity includes the following steps:

obtaining a first engine oil pressure, a first friction torque and a first engine crankshaft rotating speed under the rated power of an engine;

obtaining the initial viscosity of the engine oil according to the model of the engine oil;

and substituting the first engine oil pressure, the first friction torque and the first engine crankshaft rotating speed into a custom engine oil viscosity calculation formula by combining the engine crankshaft diameter and the engine oil initial viscosity, and calculating to obtain an engine oil viscosity relation coefficient.

Specifically, in step S2, the method for calculating and obtaining the current oil viscosity of the engine under the current power according to the current oil pressure, the current friction torque, and the engine crankshaft speed obtained under the current power of the engine through monitoring, and by combining the engine crankshaft diameter and the oil viscosity relation coefficient includes the following steps:

monitoring and obtaining the current engine oil pressure, the current friction torque and the engine crankshaft rotating speed under the current power of the engine;

obtaining the diameter of an engine crankshaft and the viscosity relation coefficient of engine oil;

and substituting the current engine oil pressure, the current friction torque and the engine crankshaft rotating speed into a custom engine oil viscosity calculation formula by combining the engine crankshaft diameter and the engine oil viscosity relation coefficient, and calculating to obtain the current engine oil viscosity under the current power of the engine.

It should be noted that, in the embodiment of the present application, the method may calculate the viscosity of the engine oil in real time based on the vehicle operation network connection big data and the engine oil physicochemical parameters, and obtain the viscosity of the engine oil according to the real-time calculation. As shown in fig. 2, the implementation path is as follows:

(1) and the vehicle operation module is used for sensing vehicle operation condition analog signals by a sensor in the vehicle operation process, processing and analyzing the signals by each ECU to convert the signals into digital signals, and communicating the digital signals in a CAN Bus in a message form.

(2) The data acquisition module acquires related messages and GPS data, the related messages and the GPS data are transmitted to the data channel in a diary mode through a 4G/5G network, the message channel Kafka receives the data, the data are analyzed and processed through the real-time calculation module and the off-line calculation module, and the results are stored in the corresponding storage units.

(3) And carrying out modeling and data analysis in a Python environment of the data center, and storing the result in a storage unit.

As shown in fig. 2, in the vehicle operation module, a sensor senses vehicle operation condition information in the vehicle operation process, and the vehicle operation condition information is processed and analyzed by each ECU and communicated with the CAN Bus in the form of a message;

the data acquisition module acquires related messages and GPS data, the related messages and the GPS data are transmitted to a message channel of the data center station in a diary mode through a 4G/5G network, the message channel Kafka receives the data, the data are processed and analyzed through the real-time calculation module and the off-line calculation module, and the results are stored in corresponding storage units;

and carrying out modeling and data analysis in a Python environment of the data center, and storing the result in a storage unit.

In a second aspect, referring to fig. 3, an embodiment of the present invention provides a vehicle oil viscosity real-time prediction apparatus for performing the vehicle oil viscosity real-time prediction method mentioned in the first aspect, where the apparatus includes:

the monitoring unit is used for detecting and obtaining first engine oil pressure, first friction torque and first engine crankshaft rotating speed under the rated power of the engine and is also used for monitoring and obtaining current engine oil pressure, current friction torque and engine crankshaft rotating speed under the current power of the engine;

the viscosity relation coefficient calculation unit is used for calculating and obtaining an engine oil viscosity relation coefficient according to the first engine oil pressure, the first friction torque and the first engine crankshaft rotating speed by combining the engine crankshaft diameter and the initial engine oil viscosity;

and the engine oil viscosity calculating unit is used for calculating and obtaining the current engine oil viscosity under the current power of the engine according to the current engine oil pressure, the current friction torque and the engine crankshaft rotating speed by combining the engine crankshaft diameter and the engine oil viscosity relation coefficient.

In the embodiment of the application, the engine oil condition is monitored, the comprehensive evaluation of multiple factors of a vehicle is combined, the viscosity of the engine oil of the vehicle is reasonably predicted, and the engine oil monitoring system has the advantages of low cost, convenience in operation and high accuracy.

Specifically, the device is based on the user-defined oil viscosity computational formula, and the user-defined oil viscosity computational formula is:

wherein the content of the first and second substances,

eta is the viscosity of the engine oil, k is the coefficient of the relationship between the viscosity of the engine oil, p_{Oil pressure}For oil pressure, T_{Friction of}D is the diameter of an output shaft of the engine, and n is the rotating speed of a crankshaft of the engine.

It should be noted that, according to the Stribeck curve, the comprehensive influence of the factors such as the viscosity, the rotating speed, the oil film thickness and the working pressure of the part of the lubricating oil on the friction factor f under different lubricating states can be clearly analyzed, and the formula is as follows:

in the formula (1), D is the diameter of the rotating shaft of the part, i.e., the diameter of the output shaft of the engine, h is the thickness of the oil film, η is the viscosity of the lubricating oil, n is the rotational speed of the crankshaft of the engine, Load is the pressure to which the part is subjected, and f is the coefficient of friction.

The oil film thickness is dependent on the oil pressure, i.e. h ═ kp_{Oil pressure}，p_{Oil pressure}Representing the oil pressure, and k is a coefficient of relationship.

Because the friction coefficient is equal to the ratio of friction torque to part bearing pressure, the formula (1) can be rewritten to obtain a new oil viscosity calculation method, namely, a custom oil viscosity calculation formula:

calculating k value, and searching the initial viscosity eta of the engine oil in an engine oil physicochemical database according to the brand information of the vehicle and the engine oil added to the vehicle₀And then obtaining the oil pressure and the friction torque, using the oil pressure and the friction torque under the rated power, substituting the values into the formula (2) to calculate the k value.

According to a preset calculation period, regularly calculating and calculating the viscosity value of the engine oil, calculating the viscosity value of the engine oil of each vehicle according to a formula (2), and further comparing the viscosity value with the initial viscosity to obtain the current viscosity ratio, namely

Further, the device also comprises an engine oil type analyzing unit which is used for obtaining the initial viscosity of the engine oil according to the engine oil type.

Further, the device also comprises a viscosity ratio calculating unit which is used for calculating the current viscosity ratio between the current oil viscosity and the initial oil viscosity according to the preset period.

Further, the device also comprises a viscosity alarm unit which is used for comparing the current viscosity ratio with the upper limit value and the lower limit value of the viscosity ratio and carrying out oil viscosity alarm if the current viscosity ratio is not between the upper limit value and the lower limit value of the viscosity ratio.

It should be noted that the viscosity of the engine oil is an important index of the performance and the service life of the engine oil, and the viscosity characteristic of the engine oil is selected according to different configurations of the vehicle and actual operating conditions of the vehicle;

the oil is wasted due to excessive viscosity, the economical efficiency is poor, the viscosity is too low, and the lubrication is insufficient, so that the part abrasion is caused, and the service life of parts is reduced;

through the engine oil viscosity alarm, a driver can be informed to replace the engine oil in time, so that the waste of fuel oil and the abrasion of parts are avoided.

It is noted that, in the present application, relational terms such as "first" and "second", and the like, are used solely to distinguish one entity or action from another entity or action without necessarily requiring or implying any actual such relationship or order between such entities or actions. Also, the terms "comprises," "comprising," or any other variation thereof, are intended to cover a non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements does not include only those elements but may include other elements not expressly listed or inherent to such process, method, article, or apparatus. Without further limitation, an element defined by the phrase "comprising an … …" does not exclude the presence of other identical elements in a process, method, article, or apparatus that comprises the element.

The foregoing are merely exemplary embodiments of the present application and are presented to enable those skilled in the art to understand and practice the present application. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments without departing from the spirit or scope of the application. Thus, the present application is not intended to be limited to the embodiments shown herein but is to be accorded the widest scope consistent with the principles and novel features disclosed herein.