BACKGROUND AND SUMMARY OF THE INVENTION

The invention relates to a display unit for a hybrid vehicle, in particular for displaying the fuel consumption and/or the residual range.

A large number of methods for determining and displaying residual ranges in motor vehicles, in particular also in electric vehicles and/or hybrid vehicles, is already known.

At present, a residual range (basic residual range) which is obtained from the ratio of the current content of the fuel tanks or content of the energy store with respect to the current fuel consumption or energy consumption is determined in virtually every vehicle and displayed, for example, within the scope of an onboard computer function or in the combination instrument.

DE 196 12 062 B4 discloses a display unit for data which are dependent on the energy consumption of a vehicle, wherein instead of a residual range value a range of values of the residual range is displayed and is determined as a function of the quantity of energy currently contained in the energy store, taking into account various driving styles and various driving conditions. The limits of the range of values can be determined taking into account various driving styles and various driving conditions of a vehicle-specific, and if appropriate, of a driver-specific consumption spectrum. By evaluating the individual driving behavior of the driver over a specific time period, the displayed range of values of the residual range can be adapted empirically.

For example, DE 10 2009 039 092 A1 discloses a method for determining at least two of the different defined residual ranges in such a way that through their representation the driver can quickly recognize whether his driving style is energy-efficient or how great is the difference between his driving style and an energy-efficient driving style.

DE 10 2011 116 313 A1 discloses a display of energy influences in a hybrid vehicle, wherein, in particular, the three variables of the overall fuel consumption, electric energy intake and energy reflux from the recuperation are indicated.

DE 10 2015 222 795 A1 discloses a display unit by means of which, in the event of a temporary failure of partial components, the display of the residual range which is dependent thereon can be masked out.

The object of the invention is to provide a functional extension of a display system for displaying the residual range.

The invention relates to a display unit for a hybrid vehicle having at least one internal combustion engine-powered drive and at least one electric motor-powered drive. The display unit comprises the following components: a first electronic determining module for determining the proportion of the current or averaged total fuel consumption which is used to charge the energy accumulator for the electric motor-powered drive and/or for determining the proportion of the current or averaged overall fuel consumption which is used to drive the hybrid vehicle; and a first display element for displaying at least this determined charge/fuel proportion and/or this determined drive/fuel proportion in addition to the overall fuel consumption.

In particular, the charge/fuel proportion and/or the drive/fuel proportion are determined from the current or averaged overall fuel consumption when the acceleration pedal is actuated or in the case of an automatic increase in the load point in the at least partially internal combustion engine-powered drive mode.

If the internal combustion engine-powered drive is a range extender, the display of the drive/fuel proportion would be the proportion which corresponds to the recharging of the energy extracted for the electric motor-powered drive.

The basic concept of the invention is therefore to control a consumption display in such a way that the driver is provided with knowledge about how the high-voltage accumulator is charged, in particular with which fuel consumption and how quickly during travel by branching off internal combustion engine-provided power, in particular after the load has been raised.

The invention is based on the following considerations.

Hybrid vehicles are currently equipped with a charging function which can charge the traction battery (high-voltage accumulator) during travel by branching off internal combustion engine-provided power (raising the load point) by means of an electric machine.

From the point of view of the driver, the additional information about how quickly the accumulator is currently being charged (acquired electrical range per unit of time or per unit of distance traveled) and if the accumulator can make available the desired electrical range can be useful during an active charging function onboard, that is to say during travel.

The currently known display strategies do not provide a display which provides the driver with additional quantitative information which goes beyond the current charging status.

In the load point raising mode, the internal combustion engine or range extender makes available both the power for the direct propulsion of the vehicle at the wheel as well as the power which is converted into electrical energy in the electric machine.

Currently, both proportions (propulsion and charging proportion) are combined in the instantaneous fuel consumption display and are not indicated separately. The propulsion proportion can be metered directly by the driver by means of the accelerator pedal, but the charging proportion is regulated by the operating strategy, and the driver does not have any direct influence on it.

It is a disadvantage that a very high average consumption or instantaneous consumption is suggested to the driver during the charging phase and there is no plausible explanation as to why the consumption is so high and how it is made up during the charging phase. It is a further disadvantage that the behavior of the instantaneous fuel consumption display cannot be controlled/metered directly by the driver, as the two proportions are displayed in a superimposed fashion.

The invention is intended to display the current charging power or charging speed plotted against the raising of the load point in an electrical range prediction per unit of time or per unit of distance traveled. Furthermore, the instantaneous fuel consumption display is preferably subdivided into a propulsion proportion and a charging proportion as a function of the current charging power or charging rate.

This information is displayed to the driver as additional information, in order, for example, to assist the route planning or to permit determination of costs in the comparison between costs per battery charge at the charging plug and costs per onboard charging.

This results, for example, in the following units which the driver can configure freely in the vehicle:

(i) charged electrical range in [km] per unit of time [min] and charged electrical range in [km] per unit of distance traveled, and/or

(ii) separate fuel consumption display, e.g. [liters per 100 km], [liters per unit of time], [liters per km of charged electrical range], [charged electrical range in km from one liter], where only the quantity of fuel consumed to make available the charging power is taken into account or dimensionless (that is to say relative) (e.g. zero—low—medium—high).

The present invention advantageously represents the fuel consumption in a manner which can be freely selected by the customer; provides various representation possibilities; and displays the specific fuel consumption during the charging phase.

Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of one or more preferred embodiments when considered in conjunction with the accompanying drawings.

