DE102020205865B4 - Driver assistance system for a battery-powered motor vehicle as an information display - Google Patents

Abstract

Driver assistance system of a battery-powered motor vehicle as an information display (4), characterized in that the driver assistance system has an on-board measuring device (5) for determining usable energy charged in the battery system (2) during a current charging process as electrochemically stored energy and for outputting an assigned useful energy signal value, - a vehicle-mounted measuring device (8) for determining electrical energy fed in from a charging station (1) during the current charging process and for outputting an assigned charging energy signal value, - a computing unit (7) which useful energy signal value and the associated charging energy signal value is supplied and which calculates a charging efficiency (η) by dividing the useful energy signal value by the charging energy signal value and/or calculates a charging loss energy (LVE) by subtracting the useful energy signal value from the charging energy signal value, and- a vehicle g-side monitor (11) on which the calculated value of the charging efficiency (η) and/or the value of the charging energy loss (LVE) are displayed.

Description

The invention relates to a driver assistance system of a battery-electric plug-in hybrid and electric vehicle as an information display according to the preamble of claim 1. The term "battery-electric motor vehicle" is to be understood here in general terms and is intended to include in particular purely electric vehicles and plug-in hybrid vehicles.

When refueling a motor vehicle with an internal combustion engine drive with gas or liquid fuel, there is practically no or negligible refueling energy loss, ie the energy in the fuel consumed by the filling station corresponds to the useful energy contained in the vehicle tank. On the other hand, when charging battery systems in motor vehicles with battery-electric drives, for example in electric or hybrid vehicles, the charging power has a non-negligible influence on the energy balance due to the electrical losses that depend on it. In a manner known per se, this is also strongly negatively influenced, in particular with high charging powers, in addition to the associated electrical losses, if the electrical losses converted into heat have to be dissipated at the same time by active cooling systems with additional electrical energy consumption.

Driver assistance systems as information displays are generally known both in motor vehicles with conventional internal combustion engine drives and in vehicles with an electrified drive train through to purely electric vehicles for displaying consumption during driving. In particular, this is information on current consumption, average consumption and total consumption, which can be called up via an on-board computer for display on a monitor.

A generic information display is specifically required for this purpose DE 10 2014 219 661 A1 known, with which a current value for a range per full charge or an average value for the range per full charge can be displayed in a battery-electric motor vehicle.

Next is a charging system of a battery-electric motor vehicle DE 10 2012 217 580 A1 known, with which the aim is to approach a charging peak efficiency of about 90% in a charging process using control algorithms in order to charge as cost-effectively as possible. Charging losses are measured here during the charging process using sensors and taken into account in the charging optimization during the charging process.

the DE 10 2018 127 472 A1 discloses a method of preparing for charging a battery. the DE 102 46 383 A1 discloses a method and an apparatus for calculating the charging efficiency and the amount of electric charge of a battery.

The object of the invention is to transparently present and display a charging efficiency and/or a charging loss energy to a vehicle user for their own assessments and decisions.

This object is achieved with the features of claim 1. Advantageous developments of the invention are disclosed in the dependent claims.

According to claim 1, the driver assistance system has an on-board measuring device for determining usable energy loaded into the battery system during a current charging process as electrochemically stored energy, the measuring device emitting a corresponding useful energy signal value.

The driver assistance system also has an on-board measuring device for determining the electrical energy fed in from a charging station during the current charging process, with a charging energy signal value either being made available here or being integrated by the on-board measuring device from the time-resolved current-voltage signals.

The driver assistance system also includes a computing unit which is supplied with the useful energy signal value and the associated charging energy signal value and which calculates a charging efficiency (η) by dividing the useful energy signal value by the charging energy signal value and/or by subtracting the useful energy signal value from the Charging energy signal value calculates a charging loss energy.

The driver assistance system also has a monitor on the vehicle, on which the calculated value of the charging efficiency (η) and/or the value of the charging energy loss are displayed.

The system components required according to the invention are described and claimed in the application as separate functional units. However, this should also include embodiments and system components that may already be partially present in an electric vehicle and may be partially contained or integrated in a battery management system and/or a monitor system and adapted and used according to the invention.

According to the invention, an energetic charging efficiency (η) and/or a charging loss energy is advantageously transparently displayed to a vehicle user for a specific charging process. Without such information, it is difficult for the vehicle user to assess what influence the charging capacity has on the overall energy balance and how potential for optimization can be used through personal decisions and actions.

The electrical energy fed in during a charging process is preferably recorded in a vehicle battery management system (BMS) and calculated by E e = ∫ U(t) I(t) dt where U(t) is a recorded time-dependent voltage value and I( t) is a detected time-dependent current value.

The usable energy charged during a charging process is preferably determined with E _n = state of charge · nominal energy, with the nominal energy being a parameter derived from the current capacity of the battery system and the nominal voltage and the state of charge in the battery management system (BMS) from current integration and characteristic diagrams the no-load voltage is determined.

The indication of the charging efficiency (η) and/or the value of the charging loss energy is preferably stored on the monitor after the completion of a charging process for the information of a vehicle user. The end of a charging process can be determined via the battery management system; if necessary, a signal from an electrical plug fuse can also be used to indicate that the plug connection to a charging station has been interrupted. Since a vehicle user generally does not remain in the vehicle during the charging process, the display according to the invention is sufficient after a current charging process. In principle, however, current values can also be displayed during a charging process.

As further information for efficiency-optimized charging, the vehicle user can be given a recommendation for future charging processes with an adapted charging power based on the time determined in which the vehicle was connected to the charging station and the effective charging time. This is always useful when the charging process is shorter than the total time at the charging station due to the selected charging power.

The determined values are preferably displayed immediately after the end of a charging process, but they can also be stored and called up by a vehicle user for display. Advantageously, several such displayed values from previous charging processes can be stored so that they can be called up, so that a vehicle user can compare different charging processes.

Particularly advantageously, the values and displays of a charging efficiency (η) and/or a value of the charging loss energy assigned to a charging process can be stored in a retrievable manner together with further information. Information with details of the useful energy charged in each case and/or with details of the location of the respective charging station is particularly suitable here, possibly using navigation data available in the vehicle. Additional information relating to the charging date and/or the charging time and/or the charging duration and/or the charging capacity can also be stored. With this information, a vehicle user can, for example, make decisions as to which charging stations should be used for him in a cost-effective and/or environmentally friendly manner. For example, if the range is still sufficient, he can skip a rapid charging station with required cooling that he used some time ago and use a later, more efficient charging station. With the above retrievable data storage, a database can be built up for the charging stations located in the usual driving area of a vehicle user with their charging properties. A vehicle user thus receives transparent information for subjective analyzes and charging decisions.

The information can be displayed directly in the multi-media interface (MMI) or, like other vehicle information, can be visualized via over-the-air data transmission on other media (apps or similar).

In principle, the stored data can optionally also be fed to an analysis unit, which uses this to determine recommendations for a vehicle user that can be displayed on the monitor for efficiency optimization during charging processes.

A method for operating a driver assistance system with the above features is also claimed. The invention is explained in more detail with reference to a drawing.

• 1 zeigt schematisch eine Ladestation mit einem angeschlossenen batterieelektrischen Antriebsstrang eines Kraftfahrzeugs; und
• 2 zeigt schematisch ein Fahrerassistenz-System eines batterieelektrisch angetriebenen Kraftfahrzeugs als Informationsanzeige.

Show it:

• 1 schematically shows a charging station with a connected battery-electric drive train of a motor vehicle; and
• 2 shows schematically a driver assistance system of a battery-powered motor vehicle as an information display.

In 1 a charging station 1 with a traction battery 2 connected to it is shown in highly schematic form, which drives an electric drive 3, represented schematically by an electric motor M, in a controlled manner.

1 is intended to show a current charging process in which electrical energy is fed from the charging station 1 into the traction battery 2. The charging station 1 is intended here, for example, to be a rapid charging station with a high charging capacity, as a result of which electrical losses converted into heat have to be dissipated by an active cooling system (not shown). The energy lost during the charging process (LVE), which is no longer available as useful energy in the traction battery 2 , is indicated schematically by the arrow 3 .

In 2 a driver assistance system of a battery-electric vehicle is shown in a highly schematic form as an information display 4 for the current charging process. For this purpose, a vehicle-side measuring device 5 is provided for determining usable energy loaded into the traction battery 2 during the current charging process, with the measuring device 5 sending an assigned useful energy signal value to a computing unit 7 via the line 6 .

A measuring device 8 is also provided for determining the electrical energy fed in from the charging station 1 during the current charging process, with a corresponding charging energy signal value being fed to the computing unit 7 via the line 9 .

In the arithmetic unit 7, a charging efficiency η is preferably calculated after the charging process by dividing the useful energy signal value by the charging energy signal value and/or by subtracting the useful energy signal value from the charging energy signal value, a charging loss energy (LVE) is calculated.

The calculated values are fed to a monitor 11 via a line 10 and displayed in the field of vision of a vehicle user.

Reference List

1

charging station

2

traction battery

3

arrow

4

information display

5

measuring device

6

management

7

unit of account

8th

measuring device

9

management

10

management

11

monitor

Claims (9)

Driver assistance system of a battery-electric motor vehicle as an information display (4), characterized in that the driver assistance system - a vehicle-side measuring device (5) for determining usable energy charged in the battery system (2) during a current charging process as electrochemically stored energy and for outputting an assigned useful energy signal value, - a vehicle-mounted measuring device (8) for determining the electrical energy fed in from a charging station (1) during the current charging process and for outputting an assigned charging energy signal value, - a computing unit (7) which useful energy signal value and the associated charging energy signal value is supplied and which calculates a charging efficiency (η) by dividing the useful energy signal value by the charging energy signal value and/or calculates a charging loss energy (LVE) by subtracting the useful energy signal value from the charging energy signal value, and - a fa vehicle-side monitor (11) on which the calculated value of the charging efficiency (η) and/or the value of the charging loss energy (LVE) are displayed. driver assistance system claim 1 , characterized in that the electrical energy (E _e ) fed in during a charging process is detected and calculated in an on-board battery management system (BMS). $${\text{E}}_{\text{e}}={\displaystyle \int \text{U(t)}\cdot }\text{I}\left(\text{t}\right)\text{German}$$

where U(t) is a sensed time-dependent voltage value and I(t) is a sensed time-dependent current value. driver assistance system claim 2 or 3 , characterized in that the charged during a charging usable energy (E _n ) is determined with $${\text{E}}_{\text{n}}=\text{state of charge}\cdot \text{rated energy}$$

wherein the rated energy is a parameter derived from the current capacity of the battery system (2) and the rated voltage and the state of charge in the battery management system (BMS). Current integration and maps of the no-load voltage is determined. Driver assistance system according to one of the Claims 1 until 3 , characterized in that the charging efficiency (η) and/or the value of the charging energy loss (LVE) is displayed on the monitor (11) after completion and/or during a current charging process. driver assistance system claim 4 , characterized in that the determined values are stored and can be called up by a vehicle user for display. driver assistance system claim 5 , characterized in that several values determined from previous charging processes are stored so that they can be called up. Driver assistance system according to one of the Claims 4 until 6 , characterized in that the values and displays of a charging efficiency (η) and/or a value of the charging loss energy (LVE) associated with a charging process are stored in a retrievable manner together with further information, in particular with information on the useful energy charged in each case and/or with information on the location of the respective charging station (1), if necessary using navigation data and/or with information on the charging date and/or charging time and/or with information on charging duration and/or charging capacity. driver assistance system claim 7 , characterized in that the stored data are supplied to an analysis unit, which determines from them on the monitor (11) recommendations to a vehicle user for efficiency optimization during charging processes. Method for operating a driver assistance system according to one of Claims 1 until 8th .

Images