CN113982773A

CN113982773A - Electronic Control Unit (ECU) and method of monitoring oil quality in a vehicle

Info

Publication number: CN113982773A
Application number: CN202110844211.3A
Authority: CN
Inventors: P·R·拉奥; S·K·汉德
Original assignee: Robert Bosch GmbH; Robert Bosch Engineering and Business Solutions Pvt Ltd
Current assignee: Robert Bosch GmbH; Bosch Global Software Technologies Pvt Ltd
Priority date: 2020-07-27
Filing date: 2021-07-26
Publication date: 2022-01-28

Abstract

The present disclosure proposes an electronic control unit (ECU (101)) adapted to monitor and indicate oil quality in a vehicle. The vehicle comprises an ECU (101), an oil pump (102) and at least one pressure sensor (103) in an outlet line of the oil pump (102). In step 201, the ECU stores a desired value of pressure in the oil pump outlet line for a set of engine operating conditions. In step 202, the ECU receives pressure transients for the set of engine operating conditions from the pressure sensor (103). In step 203, the ECU (101) compares the ideal value with an instantaneous value above a set of predefined activation conditions to determine a deviation. In step 204, the ECU (101) analyzes the deviation to calculate a correction factor. In step 205, the ECU (101) operates the oil pump (102) based on the calculated correction factor.

Description

Electronic Control Unit (ECU) and method of monitoring oil quality in a vehicle

Technical Field

The present disclosure relates to an ECU and a method of monitoring oil quality in a vehicle.

Background

In conventional systems for vehicles, the oil quality is known by an oil quality sensor measuring the electrical conductivity of the oil or by a physical inspection at rest, which may or may not be performed by the user since there is no warning light regarding the oil quality. Even if a user performs a physical inspection of the oil, the perceived quality of the oil may appear different for different users. As the physical state (color and viscosity) may be perceived differently by different users, or the end user may not always know the exact state required for engine oil quality. Furthermore, there is no deterministic/robust system that can always monitor the quality of the engine oil. Therefore, there is a need for a deterministic logic based on which oil quality can be quantified, wherein oil quality is correlated to engine and peripheral system properties.

Patent application "US 2006155502A-method for determining oil condition" discloses a method for determining oil condition (i.e. oil condition corresponding to oil age or oil damage) having the following steps: a) measuring the temperature of the oil or of the part through which the oil flows, coordinating each measured temperature with a temperature range defined by upper and/or lower limits; b) once the measured temperature exceeds or falls below the limits of the temperature range, measuring the period of time that the measured temperature stays within the range; c) in addition, during the period of time measured in step b), the flow of oil flowing during this period of time is integrated; d) determining the oil age or oil damage characteristic of the current temperature range from the integration of the time period measured in step b) and the oil flow determined in step c).

Drawings

Embodiments of the invention are described with reference to the following drawings:

FIG. 1 depicts a system (100) for monitoring oil quality in a vehicle; and

fig. 2 illustrates method steps (200) of monitoring oil quality in a vehicle.

Detailed Description

FIG. 1 depicts a system for monitoring oil quality in a vehicle. The system comprises an electronic control unit (ECU (101)) adapted to monitoring the quality of the oil in the vehicle, an oil pump (102) and at least a pressure sensor (103) in the outlet line of the oil pump (102). The pressure sensor (103) is in communication with the ECU (101). The ECU (101) includes a microcontroller, a memory unit, an input/output unit, and at least a communication module. An oil pump (102) circulates engine oil at a predetermined pressure to a rotary bearing, a sliding piston, and a camshaft of an internal combustion engine. The oil pump (102) may be one of many types known to those skilled in the art, such as a solenoid-based oil pump (102). This oil pump (102) is energized by the ECU (101). A pressure sensor (103) at the outlet line of the oil pump (102) measures the instantaneous value of the pressurized oil and sends it to the ECU (101).

Fig. 2 illustrates method steps (200) for detecting oil quality in a vehicle by means of the system depicted in fig. 1. The system comprises an ECU (101) adapted to monitor the quality of the oil in the vehicle, an oil pump (102) and at least a pressure sensor (103) in the outlet line of the oil pump (102). In step 201, the ECU (101) stores a desired value of pressure in the oil pump outlet line for a set of engine operating conditions. The set of engine operating conditions includes, but is not limited to, engine speed, engine load, and at least engine friction. In an embodiment, the ideal values are stored in a list in the ECU (101) memory unit, as shown in table 1 below.

Duty ratio (unit is%)	Engine friction (unit is Nm)	Engine negativeCarrier (unit is%)	Engine speed (unit is rpm)	Ideal pressure (bar) at outlet line of oil pump (102)
					0	T1	L1	N1	P1
25	T2	L2	N2	P2
					50	T3	L3	N3	P3
N	Tn	Ln	Nn	Pn

Table 1.

It is apparent from the table that the pressure value in the oil pump outlet line is measured at a specific engine speed, engine load and engine friction corresponding to a specific duty cycle of the oil pump. For example, at an engine speed of N2 rpm, an engine load of L2, and an engine friction of T2 Nm, the oil pump (102) is energized by 25%, and the desired pressure in the outlet line of the oil pump (102) is P1 bar. Similar correlations are found between the tabulated parameters and the pressure at the oil pump (102) outlet line for different parameter values and stored in the ECU (101).

In step 202, the ECU (101) receives pressure transients for the set of engine operating conditions from the pressure sensor (103). This is a real-time value observed while the vehicle is running. For example, currently when the vehicle is operating at an engine speed of N2 rpm, an engine load of L2, an engine friction of T2 Nm, the oil pump (102) is energized by 25%, and the instantaneous or real-time pressure measured in the outlet line of the oil pump (102) is P1r bar.

In step 203, the ECU (101) compares the ideal value with an instantaneous value above a set of predefined activation conditions to determine a deviation. The set of predefined activation conditions includes an engine temperature, an oil temperature, and at least an oil amount. The activation conditions are pre-requisite values of parameters such as, but not limited to, engine temperature, oil temperature and at least oil quantity, below which no comparison between the ideal value and the instantaneous value takes place. The activation condition is predetermined for a combination of the engine type and the engine oil. For example, in an "X" internal combustion engine designed to be lubricated by "Y" grade oil, the engine temperature must be higher than the so-called 80 degrees celsius, the oil temperature must be higher than 70 degrees celsius, and the oil volume must be higher than a minimum operating level (e.g., 750 milliliters) in order for a comparison to occur between ideal and instantaneous values. Based on the comparison, a model is used to calculate the deviation. The model takes into account deviations in pressure, indicated by using a comparison and averaging method, such as a linear average or EWMA (exponentially weighted moving average) filter or time input of only more than a constant value and other methods known to those skilled in the art. The model also adjusts for deviations in tolerance values based on various factors such as engine friction, oil temperature, ambient pressure, and oil type, as oil pressure will change as the system ages.

In step 204, the ECU (101) analyzes the deviation to calculate a correction factor. The deviations are analyzed for various ranges of engine operating conditions and correction factors are calculated. The correction factor acts as feedback to the oil pump (102). When oil quality deteriorates, more or less duty cycle is required to achieve the same pressure in the oil pump (102) outlet line. This is captured by a correction factor which is fed as feedback to the oil pump (102).

In step 205, the ECU (101) operates the oil pump (102) based on the calculated correction factor. The correction factor is continuously calculated and dynamically updated in the ECU (101). Meanwhile, if the oil quality deterioration exceeds a threshold value, i.e., when the required pressure at the outlet line of the oil pump (102) cannot be maintained even after the correction factor is calculated, the ECU (101) indicates that an oil change is required. The indication is given by the ECU (101) on the dashboard by audio or visual means.

The basic idea behind these method steps is to quantify the oil quality. The measured pressure of the oil is indicative of its viscosity, which in turn is a key factor in determining the quality of the oil. Viscosity may be related to the density of the oil. The density is in turn related to the oil pressure in the system using one of many equations known to those skilled in the art. Thus, we can relate viscosity to oil pressure in the system. The idea of developing an ECU (101) and method of monitoring oil quality in a vehicle provides predictive maintenance of engine oil life. This data can also be used to detect false oil or oil dilution, adulteration and impurity detection for a particular system. The concept also provides better fleet monitoring and instructions for better service and maintenance. Further, in a vehicle having a connection via the internet of things (IOT), the oil quality monitoring data collected from the ECUs and methods described above may be transmitted to a service station, thereby improving its supply chain.

It must be understood that the embodiments explained in the above detailed description are illustrative only and do not limit the scope of the present invention. Any modification of the ECU (101) and method (200) of monitoring oil quality in a vehicle is contemplated and forms part of the present invention. The scope of the invention is limited only by the claims.

Claims

1. An electronic control unit (ECU (101)) adapted to monitor oil quality in a vehicle, the vehicle comprising an oil pump (102) and at least a pressure sensor (103) in an outlet line of the oil pump (102), the pressure sensor (103) being in communication with the ECU (101), the ECU (101) being configured to:

storing a desired value of pressure in an outlet line of the oil pump for a set of engine operating conditions;

receiving pressure transients for the set of engine operating conditions from the pressure sensor (103);

comparing the ideal value with instantaneous values above a set of predetermined activation conditions to determine a deviation;

analyzing the deviation to calculate a correction factor;

the oil pump (102) is operated based on the calculated correction factor.

2. The ECU (101) of claim 1 wherein said set of engine operating conditions includes engine speed, engine load and at least engine friction.

3. The ECU (101) of claim 1, wherein the set of predefined activation conditions includes an engine temperature, an oil temperature, and at least an oil volume.

4. A method (200) of monitoring oil quality in a vehicle comprising an oil pump (102), a pressure sensor (103) in an outlet line of the oil pump (102), and at least an electronic control unit (ECU (101)), the pressure sensor (103) being in communication with the ECU (101), the method comprising:

storing (201), in the ECU (101), a desired value of pressure in an oil pump outlet line for a set of engine operating conditions;

receiving (202) pressure transients for the set of engine operating conditions from the pressure sensor (103);

comparing (203) the ideal value with instantaneous values above a set of predefined activation conditions to determine a deviation;

analyzing (204) the deviation to calculate a correction factor;

operating (205) the oil pump (102) based on the calculated correction factor.

5. The method of claim 4, wherein the set of engine operating conditions includes engine speed, engine load, and at least engine friction.

6. The method of claim 4, wherein the set of predefined activation conditions includes an engine temperature, an oil temperature, and at least an oil volume.