KR102575144B1 - Apparatus and method for estimating distance to empty of electric vehicle - Google Patents

Abstract

The present invention relates to an apparatus and method for predicting the driving range of an electric vehicle. The apparatus for predicting the possible driving range of an electric vehicle according to an embodiment of the present invention measures the driving range (DTE) based on battery available energy (SOE). a DTE calculation unit for calculating 'SOE-based DTE'; A DTE correction value calculation unit for calculating a 'DTE correction value' indicating a possible driving distance corresponding to the amount of auxiliary energy used by electric vehicle additional devices; and a DTE correction unit for correcting 'SOE-based DTE' in consideration of the 'DTE correction value'.

Description

Apparatus and method for predicting driving distance of electric vehicle

The present invention relates to an apparatus and method for predicting a drivable distance of an electric vehicle, and more particularly, to a drivable distance (drivable distance ( An apparatus and method for predicting a driving distance of an electric vehicle for improving accuracy by reducing an error of driving distance by calculating and predicting DTE).

An electric vehicle (PHEV or BEV) consists of the basic functions of a vehicle having the same components as a general vehicle, a drive motor driven by electricity to operate the vehicle, and a battery that supplies electricity to the drive motor. do.

Such an electric vehicle charges electricity in a battery and uses the charged electricity to drive a motor, thereby checking the battery status regarding the battery temperature and available energy SOE (State Of Energy) of the battery, and checking that the battery status exceeds a certain level. It is very important to manage it so that it can be maintained.

Electric vehicles provide a function of estimating the distance to empty (DTE) based on the current battery available energy and displaying it on a cluster. In particular, as the driving distance of an electric vehicle is limited according to the battery capacity, the driving distance is provided as very important driving information to the driver.

Here, the available energy (SOE) of the battery can be defined as in Equation 1 below.

이고,

이며,

이다.here,

ego,

is,

am.

는 도 1과 같은 관계성을 가지며, 배터리의 가용에너지는 수학식 1을 통해 얻을 수 있다. 도 1은 SOC(State Of Charge)와 배터리 셀전압의 관계를 나타낸 도면이다.

has a relationship as shown in FIG. 1, and the available energy of the battery can be obtained through Equation 1. 1 is a diagram showing a relationship between a state of charge (SOC) and a battery cell voltage.

Table 1 below shows SOE according to SOC and battery cell voltage. Through this, the electric vehicle can calculate the possible driving distance based on the available energy of the battery.

U _OCV (V) SOC (%) U _{OCV|SOC=[0%,SOC]} SOE (%) 3.300 0.0 3.300 0.0 3.877 25.9 3.744 24.5 3.988 51.9 3.839 50.3 4.070 77.8 3.903 76.7 4.210 100.0 3.957 100.0

However, when an electric vehicle calculates a drivable distance based on available energy of a battery, an error may occur in the drivable distance depending on the driving environment. This is because not only the battery is used to drive the motor, but also the battery is used to drive additional devices.

Representative additional devices include an air conditioner to satisfy the vehicle's cooling/heating performance and an LDC (Low voltage DC-DC Converter) to convert high-voltage DC power to low-voltage AC power and charge the low-voltage battery. there is. Accordingly, air conditioning devices or LDCs, etc., use high-voltage batteries, which may be a factor that causes errors in the driving distance when calculating the driving distance based on the available energy of the battery.

Therefore, it is necessary to prepare a method for predicting the driving distance in consideration of battery usage of additional devices when calculating the driving distance based on the available battery energy of the electric vehicle.

Republic of Korea Patent Registration No. 10-1394867 (Registered on 2014.05.07)

An object of the present invention is to improve accuracy by reducing errors in the driving distance by calculating and predicting the driving distance (DTE) in consideration of the amount of auxiliary energy used by the auxiliary devices other than the energy for driving the motor of the electric vehicle. It is to provide an apparatus and method for predicting the driving range of an electric vehicle for the purpose.

An apparatus for predicting a driving range of an electric vehicle according to an embodiment of the present invention includes a DTE calculation unit for calculating a driving range (DTE) based on battery available energy (SOE); A DTE correction value calculation unit for calculating a 'DTE correction value' corresponding to the amount of auxiliary energy used by the electric vehicle additional devices; and a DTE correction unit for correcting 'SOE-based DTE' in consideration of the 'DTE correction value'.

According to an embodiment, the device further includes an auxiliary energy usage storage unit for measuring and storing an auxiliary energy usage amount of a previous driving cycle, and the DTE correction value calculation unit, when the electric vehicle is initially started, The 'DTE correction value' may be calculated using the 'auxiliary energy usage of the previous driving cycle' stored in the auxiliary energy usage storage unit.

According to an embodiment, the auxiliary energy usage measuring unit for measuring the auxiliary energy usage of a previous window; further including the DTE correction value calculating unit, when the electric vehicle is running, the auxiliary energy usage measuring unit It may be to calculate the 'DTE correction value' using the 'auxiliary energy consumption of the previous window' measured in .

The 'DTE correction value' may be defined as a function relationship between the outside air temperature and the coolant temperature.

The DTE correction unit may output a difference between the 'SOE-based DTE' and the 'DTE correction value' as a DTE correction result.

According to the embodiment, a DTE prediction unit for predicting the driving distance of the electric vehicle by externally displaying the DTE correction result; may be further included.

The DTE correction value calculator may update the 'DTE correction value' at an ignition off time point.

In addition, a method for predicting a driving distance of an electric vehicle according to an embodiment of the present invention includes calculating a driving distance (DTE) based on battery available energy (SOE); Calculating a 'DTE correction value' corresponding to the amount of auxiliary energy used by the electric vehicle additional devices; and correcting the 'SOE-based DTE' in consideration of the 'DTE correction value'.

According to an embodiment, before the step of calculating the 'DTE correction value', the step of measuring and storing the auxiliary energy consumption of the previous driving cycle; When the electric vehicle is initially started, the 'DTE correction value' may be calculated using the stored 'auxiliary energy consumption of the previous driving cycle'.

According to the embodiment, the step of measuring the auxiliary energy consumption of the previous window before the step of calculating the 'DTE correction value'; further comprising the step of calculating the 'DTE correction value', the electric vehicle While driving, the 'DTE correction value' may be calculated using the measured 'auxiliary energy usage of the previous window'.

The 'DTE correction value' may be defined as a function relationship between the outside air temperature and the coolant temperature.

The correcting step may include outputting a difference between the 'SOE-based DTE' and the 'DTE correction value' as a DTE correction result.

According to an embodiment, after the calibrating step, the step of estimating the drivable distance of the electric vehicle by externally displaying the DTE correction result may be further included.

The present invention can improve accuracy by reducing the error in the drivable distance by calculating and predicting the drivable distance (DTE) by considering the amount of auxiliary energy used by auxiliary devices excluding the energy for driving the motor of the electric vehicle. .

In addition, the present invention can improve the prediction accuracy of the drivable distance by predicting the drivable distance using the auxiliary energy usage (average energy) of the previous driving cycle at the initial stage of starting the electric vehicle.

In addition, the present invention can improve the prediction accuracy of the drivable distance by predicting the drivable distance using the auxiliary energy usage (average energy) of the previous window while the electric vehicle is driving.

1 is a diagram showing the relationship between SOC (State Of Charge) and battery cell voltage;
2 is a diagram showing an apparatus for predicting a driving distance of an electric vehicle according to an embodiment of the present invention;
3 is a diagram showing the driving distance corresponding to the auxiliary energy consumption according to the outside air temperature and the coolant temperature;
4 is a diagram explaining a process of correcting a driving distance based on available battery energy in consideration of auxiliary energy usage;
5 is a diagram illustrating a method for predicting a drivable distance of an electric vehicle according to an embodiment of the present invention.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the accompanying drawings. However, detailed descriptions of known functions or configurations that may obscure the gist of the present invention are omitted in the following description and attached drawings. Additionally, it should be noted that the same components throughout the drawings are indicated by the same reference numerals whenever possible.

The terms or words used in this specification and claims described below should not be construed as being limited to ordinary or dictionary meanings, and the inventors are appropriately defined as terms for describing their invention in the best way. It should be interpreted as meaning and concept consistent with the technical idea of the present invention based on the principle that it can be done.

Therefore, the embodiments described in this specification and the configurations shown in the drawings are only one of the most preferred embodiments of the present invention, and do not represent all of the technical ideas of the present invention. It should be understood that there may be equivalents and variations.

In the accompanying drawings, some components are exaggerated, omitted, or schematically illustrated, and the size of each component does not entirely reflect the actual size. The present invention is not limited by the relative sizes or spacings drawn in the accompanying drawings.

When it is said that a certain part "includes" a certain component throughout the specification, it means that it may further include other components without excluding other components unless otherwise stated. In addition, when a part is said to be "connected" to another part, this includes not only the case of being "directly connected" but also the case of being "electrically connected" with another element interposed therebetween.

Singular expressions include plural expressions unless the context clearly dictates otherwise. Terms such as “include” or “have” are intended to designate the presence of features, numbers, steps, operations, components, parts, or combinations thereof described in the specification, but do not include one or more other features, numbers, or steps. , it should be understood that this does not exclude in advance the possibility of the presence or addition of operations, components, parts, or combinations thereof.

Additionally, the term “unit” used in the specification refers to a hardware component such as software, FPGA, or ASIC, and the “unit” performs certain roles. However, "unit" is not meant to be limited to software or hardware. The “copy” may be configured to reside on an addressable storage medium and may be configured to run on one or more processors. Thus, as an example, “unit” can refer to components such as software components, object-oriented software components, class components and task components, processes, functions, properties, procedures, subroutines, segments of program code, drivers, firmware, microcode, circuitry, data, databases, data structures, tables, arrays and variables. Functionality provided within components and "parts" may be combined into fewer components and "parts" or further separated into additional components and "parts".

Below, with reference to the attached drawings, embodiments of the present invention will be described in detail so that those skilled in the art can easily implement the present invention. However, the present invention may be embodied in many different forms and is not limited to the embodiments described herein. In order to clearly explain the present invention in the drawings, parts that are not related to the description are omitted, and similar parts are given similar reference numerals throughout the specification.

Hereinafter, preferred embodiments of the present invention will be described with reference to the accompanying drawings.

2 is a diagram showing an apparatus for predicting a driving distance of an electric vehicle according to an embodiment of the present invention.

As shown in FIG. 2, the apparatus for predicting the driving distance of an electric vehicle according to an embodiment of the present invention (hereinafter referred to as the 'DTE predictor', 100) is an 'additional device excluding energy for driving the motor of the electric vehicle. Accuracy can be improved by reducing errors in the driving distance (DTE) by calculating and predicting the driving distance (DTE) in consideration of the amount of energy used by the vehicle (hereinafter referred to as 'auxiliary energy').

Here, the auxiliary energy includes energy for using A/C for cooling performance, energy for using a heater for heating performance, and energy for using LDC for charging/maintaining a low-voltage battery of an electric vehicle. . Such auxiliary energy exhibits variable characteristics depending on driving conditions and outdoor temperature.

This auxiliary energy can be expressed as in Equation 2 below.

The DTE prediction device 100 includes a DTE calculation unit 110, an auxiliary energy consumption storage unit 120, an auxiliary energy consumption measurement unit 130, a DTE correction value calculation unit 140, a DTE correction unit 150, a DTE prediction unit ( 160).

First, the DTE calculation unit 110 calculates a driving distance (DTE) of the electric vehicle based on the available energy (SOE) of the battery. That is, the DTE calculation unit 110 calculates the original driving distance without considering the amount of auxiliary energy used. As described above with reference to FIG. 1, a description thereof will be omitted since it can be easily understood by those skilled in the art. Here, as the original drivable distance calculated by the DTE calculation unit 110, the SOE-based DTE calculation value is hereinafter referred to as 'DTE _SOE '.

Next, the auxiliary energy usage storage unit 120 may be a non-volatile memory, and measures and stores auxiliary energy usage in a previous driving cycle.

That is, the auxiliary energy amount storage unit 120 stores a moving average of the auxiliary energy for a predetermined time based on the outdoor temperature range in consideration of the variable characteristics of the auxiliary energy according to the operating conditions and the outdoor temperature.

Here, the amount of auxiliary energy used in the previous driving cycle is used as an initial value for the next driving cycle. That is, the amount of auxiliary energy used in the previous driving cycle is used to calculate the drivable distance at the start of the electric vehicle by the DTE correction value calculation unit 140 to be described later.

Next, the auxiliary energy usage measurement unit 130 measures the auxiliary energy usage for a previous window while the electric vehicle is driving. That is, when the next window starts at the current point in time, the auxiliary energy usage measurement unit 130 measures the auxiliary energy usage for the previous window. Through this, the auxiliary energy usage for the previous window is used for DTE calculation by the DTE correction value calculator 140 at the start of the next window.

Here, the window is a unit section to which a predetermined time interval is allocated to measure auxiliary energy usage while the electric vehicle is driving, and becomes a part constituting a driving cycle.

In addition, since the auxiliary energy usage of the previous window does not exist when the electric vehicle is initially started, the auxiliary energy usage measurement unit 130 measures the auxiliary energy usage for the previous window from the time the previous window exists. This is the reason why the DTE correction value calculation unit 140, which will be described later, applies the amount of auxiliary energy used in the previous driving cycle to the calculation of the driving distance at the initial stage of starting the electric vehicle.

The DTE correction value calculation unit 140 calculates a possible driving distance corresponding to the auxiliary energy consumption as a DTE correction value for correcting the DTE _SOE error.

Here, the DTE correction value can be defined as a functional relationship between ambient temperature and coolant temperature (ie, DTE _AUX = f (outside temperature, coolant temperature)), It represents the value obtained by calculating the average energy amount of energy consumption as the driving distance. Accordingly, the DTE correction value may be expressed as 'DTE _Aux-ij ', which is a value corresponding to a specific region of the outside air temperature and the coolant temperature, as shown in FIG. 3 . 3 is a diagram showing a driving distance corresponding to auxiliary energy consumption according to outside air temperature and coolant temperature. In this way, the DTE correction value may be defined in detail according to the outside air temperature and the coolant temperature.

On the other hand, as the display delay and change occur during DTE calculation in the initial stage of starting the electric vehicle, the average amount of auxiliary energy according to the driving environment is differentiated and stored. Then, the DTE correction value calculation unit 140 performs an update at an ignition off time. That is, the DTE correction value calculation unit 140 updates the average energy amount of the auxiliary energy consumption measured during driving with the DTE correction value of FIG. 3 . This can be expressed as in Equation 3.

Here, k is a factor representing the degree of update reflection.

Based on this, the DTE correction value calculation unit 140 uses the 'auxiliary energy consumption of the previous driving cycle' stored in the auxiliary energy consumption storage unit 120 when the electric vehicle is in the initial stage of startup, and uses the DTE correction value ('DTE _Aux- called ' _Init ').

In addition, the DTE correction value calculation unit 140 uses the 'auxiliary energy consumption for the previous window' measured by the auxiliary energy consumption measurement unit 130 while the electric vehicle is driving, and uses the DTE correction value (hereinafter referred to as 'DTE _{Aux- PreWindow} ') is calculated.

Next, the DTE compensator 150 corrects the SOE-based DTE representing the drivable distance based on available battery energy in consideration of the DTE correction value representing the drivable distance corresponding to the amount of auxiliary energy used.

To this end, the DTE correction unit 150 receives the 'DTE _SOE ' calculated by the DTE calculation unit 110, and the DTE correction value calculated by the DTE correction value calculation unit 140, that is, 'DTE _Aux-Init ' Receives 'DTE _{Aux-PreWindow} '.

Accordingly, the DTE compensator 150 corrects the driving distance based on available battery energy to the DTE correction value as shown in Equation 4 below when the electric vehicle is initially started.

Also, the DTE correction unit 150 corrects the driving distance based on available battery energy to the DTE correction value as shown in Equation 5 below when the electric vehicle is running.

Next, the DTE predictor 160 displays the DTE correction result on the DTE corrector 150 to predict the drivable distance of the electric vehicle. The DTE prediction unit 160 may display the driving distance of the electric vehicle in conjunction with a cluster.

4 is a diagram illustrating a process of correcting a driving distance based on available battery energy in consideration of auxiliary energy usage.

Referring to FIG. 4 , the available driving distance (DTE _SOE ) based on available battery energy decreases over time.

The SOE-based DTE calculation value (DTE _Final1 ) considering the auxiliary energy usage (average) of the previous driving cycle shows the DTE correction result for the DTE _SOE as much as the auxiliary energy usage (average) interval of the previous driving cycle. DTE _Final1 shows the DTE correction result in parallel to DTE _SOE . This is output as a corrected DTE correction result when the electric vehicle is in the initial stage of starting, that is, in the first window. That is, before the first window, the auxiliary energy consumption of the previous driving cycle is used for SOE-based DTE correction.

The SOE-based DTE calculation value (DTE _Final2 ) considering the auxiliary energy usage (average) of the previous window shows the DTE correction result according to the auxiliary energy usage of the previous window. In DTE _Final2 , the DTE correction result that approaches or moves away from the DTE _SOE is displayed for each window. This is output as a DTE correction result corrected according to the amount of auxiliary energy used in the previous window while the electric vehicle is driving. Specifically, at the start of the second window, the DTE correction result is output according to the amount of auxiliary energy used in the first window. Similarly, at the start of the third window to the sixth window, the DTE correction result is output according to the amount of auxiliary energy used in the previous window.

5 is a diagram illustrating a method for predicting a drivable distance of an electric vehicle according to an embodiment of the present invention.

Referring to FIG. 5 , the DTE prediction apparatus 100 calculates a driving distance based on available battery energy (ie, SOE-based DTE and DTE _SOE ) according to a conventional method (S201).

First, the DTE predicting device 100 calculates a DTE correction value (ie, DTE _{Aux_Init} ) using auxiliary energy usage of a previous driving cycle when the electric vehicle is initially started (S202) (S204). Then, the DTE prediction device 100 corrects the SOE-based DTE (ie, DTE _SOE ) in consideration of the calculated DTE correction value (ie, DTE _{Aux_Init} ) (S206). At this time, the DTE prediction apparatus 100 predicts and displays 'corrected SOE-based DTE' (ie, DTE _Final1 = DTE _SOE -DTE _{Aux_Init} ) (S207).

Next, the DTE predicting device 100 calculates a DTE correction value (ie, DTE _{Aux_PreWindow} ) using the auxiliary energy usage of the previous window when the electric vehicle is driving (S202, S203), not at the beginning of startup (S205). ). Then, the DTE prediction device 100 corrects the SOE-based DTE (ie, DTE _SOE ) in consideration of the calculated DTE correction value (ie, DTE _{Aux_PreWindow} ) (S206). At this time, the DTE prediction apparatus 100 predicts and displays 'corrected SOE-based DTE' (ie, DTE _Final2 = DTE _SOE - DTE _{Aux_PreWindow} ) (S207).

Methods according to some embodiments may be implemented in the form of program instructions that can be executed through various computer means and recorded on a computer-readable medium. The computer readable medium may include program instructions, data files, data structures, etc. alone or in combination. Program instructions recorded on the medium may be those specially designed and configured for the present invention or those known and usable to those skilled in computer software. Examples of computer-readable recording media include magnetic media such as hard disks, floppy disks and magnetic tapes, optical media such as CDROMs and DVDs, and magnetic-optical media such as floptical disks. Included are hardware devices specially configured to store and execute program instructions, such as magneto-optical media and ROM, RAM, flash memory, and the like. Examples of program instructions include high-level language codes that can be executed by a computer using an interpreter, as well as machine language codes such as those produced by a compiler.

Although the above description focuses on the novel features of the invention as applied to various embodiments, those skilled in the art will appreciate the apparatus and methods described above without departing from the scope of the invention. It will be appreciated that various deletions, substitutions, and changes in the form and detail of are possible. Accordingly, the scope of the present invention is defined by the appended claims rather than by the foregoing description. All modifications that come within the scope of equivalence of the claims are embraced by the scope of the present invention.

110: DTE calculation unit 120: auxiliary energy consumption storage unit
130: auxiliary energy usage measurement unit 140: DTE correction value calculation unit
150: DTE correction unit 160: DTE prediction unit

Claims (13)

a DTE calculation unit for calculating a DTE based on available battery energy (SOE);
A DTE correction value calculation unit for calculating a 'DTE correction value' corresponding to the amount of auxiliary energy used by the electric vehicle additional devices;
a DTE correction unit for correcting 'SOE-based DTE' in consideration of the 'DTE correction value';
Auxiliary energy consumption storage unit for measuring and storing auxiliary energy consumption of a previous driving cycle; and
Auxiliary energy consumption measurement unit for measuring the auxiliary energy consumption of the previous window (window); contains
The DTE correction value calculator,
When the electric vehicle is initially started, the 'DTE correction value' is calculated using the 'auxiliary energy consumption of the previous driving cycle' stored in the auxiliary energy usage storage unit,
When the electric vehicle is driving, the 'DTE correction value' is calculated using the 'auxiliary energy consumption of the previous window' measured by the auxiliary energy usage measurement unit,
The 'DTE correction value' is defined as a function relationship between the outside air temperature and the coolant temperature, and is a value calculated as a driving distance corresponding to the average energy amount of auxiliary energy consumption in a specific area of the outside air temperature and the coolant temperature,
The DTE compensator outputs the difference between the 'SOE-based DTE' and the 'DTE correction value' as a DTE correction result, but considers the auxiliary energy consumption (average) of the previous driving cycle. DTE correction results are output in a state parallel to ', and when the auxiliary energy consumption (average) of the previous window is considered, the DTE is output as a DTE correction result that approaches or moves away from 'SOE-based DTE' for each window. A device for predicting the driving range of an electric vehicle.
delete delete delete delete According to claim 1,
a DTE prediction unit for estimating the driving distance of the electric vehicle by displaying the DTE correction result;
A driving range prediction device further comprising a.
According to claim 1,
The DTE correction value calculator,
The drivable distance predicting device performs an update of the 'DTE correction value' at an ignition off time.
calculating a travelable distance (DTE) based on available battery energy (SOE);
Calculating a 'DTE correction value' corresponding to the amount of auxiliary energy used by the electric vehicle additional devices;
correcting 'SOE-based DTE' in consideration of the 'DTE correction value';
before the step of calculating the 'DTE correction value', measuring and storing auxiliary energy consumption of a previous driving cycle; and
Before the step of calculating the 'DTE correction value', measuring the auxiliary energy usage of the previous window;
In the step of calculating the 'DTE correction value',
When the electric vehicle is initially started, the 'DTE correction value' is calculated using the stored 'auxiliary energy consumption of the previous driving cycle'
When the electric vehicle is driving, the 'DTE correction value' is calculated using the measured 'auxiliary energy consumption of the previous window';
The 'DTE correction value' is defined as a function relationship between the outside air temperature and the coolant temperature, and is a value calculated as a driving distance corresponding to the average energy amount of auxiliary energy consumption in a specific area of the outside air temperature and the coolant temperature,
The correction step outputs the difference between the 'SOE-based DTE' and the 'DTE correction value' as a DTE correction result, and when the auxiliary energy consumption (average) of the previous driving cycle is considered, the DTE is 'SOE-based DTE DTE correction results are output in a state parallel to ', and when the auxiliary energy consumption (average) of the previous window is considered, the DTE is output as a DTE correction result that approaches or moves away from 'SOE-based DTE' for each window. A method for predicting the driving range of an electric vehicle using
delete delete delete delete According to claim 8,
After the calibrating step, estimating a driving distance of the electric vehicle by externally displaying the DTE correction result;
A driving distance prediction method further comprising a.

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