Method for controlling a hybrid electric vehicle

Abstract

Method (10) for controlling a hybrid electric motor vehicle with a foot pedal (20), having the following features: - the hybrid electric vehicle alternately assumes a first operating state (1), a second operating state (2) or a third operating state (3), - the hybrid electric vehicle operates in the first operating state (1) purely on electric motor power, - the hybrid electric vehicle operates at least partially in the second operating state (2) and third operating state (3) using its internal combustion engine and - when a predetermined pressure point of the accelerator pedal (20) is mechanically overcome in the first operating state (1), the hybrid electric vehicle is put into the second operating state (2), characterized by the following features: - Driving in the first operating state (1) is limited to a first driving speed of 55 km / h, - if the hybrid electric vehicle falls below the first driving speed in the second operating state (2) or third operating state (3), the hybrid electric vehicle is returned to the first operating state (1), - if the hybrid electric vehicle exceeds a second driving speed of 70 km / h in the second operating state (2), the hybrid electric vehicle is switched to the third operating state (3), - the first operating state (1) and the second operating state (2) are selectively deactivated by means of a button on the hybrid electric vehicle and - the pressure point is activated in the first operating state (1) and second operating state (2) and deactivated in the third operating state (3).

Description

[0001] The present invention relates to a method for controlling a hybrid electric vehicle. The present invention further relates to a corresponding hybrid electric vehicle, a corresponding computer program, and a corresponding storage medium. State of the art

[0002] A hybrid electric vehicle (HEV) is a motor vehicle powered by at least one electric motor and another energy converter, usually an internal combustion engine. Various methods exist for controlling hybrid electric vehicles of this type. In some cases, the internal combustion engine is switched off as long as the driver is not demanding any or very little power.

[0003] DE 10 2010 039 375 A1 describes a method for operating a powertrain, in which a pedal is provided. Below a certain pressure point of the pedal, the vehicle is driven purely electrically, and after the pressure point, the vehicle is to be driven in hybrid mode.

[0004] DE 10 2013 021 817 A1 describes a hybrid vehicle in which two operating modes are possible, which are switched on by the brake pedal.

[0005] WO 2015 / 024 974 A1 describes a hybrid electric vehicle control system, whereby the control system can provide additional torque.

[0006] DE 101 40 366 A1 describes hybrid drives for motor vehicles, wherein in a first operating mode the vehicle is driven purely electrically.

[0007] GB 2 523 589 A, DE 10 2009 049 497 A1 and DE 10 2006 012 515 A1 each disclose the subject matter of the preamble of claim 1. Disclosure of the invention

[0008] The invention provides a method for controlling a hybrid electric vehicle, a corresponding hybrid electric vehicle, a corresponding computer program and a corresponding storage medium according to the independent claims.

[0009] One advantage of this solution lies in a predefined driving mode that can be activated via a button. This mode incorporates an activatable accelerator pedal pressure point on the accelerator pedal or foot lever of the hybrid vehicle, which limits the vehicle's speed. Up to this pressure point, the vehicle is driven purely electrically, and its speed is limited to a first predefined speed (e.g., 55 km / h). If the accelerator pedal pressure point is exceeded, the combustion engine in the hybrid vehicle starts, and the speed limit is lifted. If a second predefined speed (e.g., 70 km / h) is exceeded, the accelerator pedal pressure point is deactivated. If the vehicle speed falls below the first predefined speed (55 km / h), the accelerator pedal pressure point is reactivated, the combustion engine is switched off, and the hybrid vehicle resumes purely electric drive.

[0010] Further advantageous embodiments of the invention are specified in the dependent patent claims. Brief description of the drawings

[0011] An embodiment of the invention is shown in the drawings and is described in more detail below. Fig. Figure 1 shows a state diagram of a hybrid electric vehicle according to the invention, corresponding to the unified modeling language (UML). Fig. Figure 2 schematically shows the sequence of the procedure with increasing activation of the driving foot lever. Embodiments of the invention

[0012] Fig. Figure 1 illustrates, according to ISO / IEC 19505, the basic behavior of the preferred embodiment of a hybrid electric vehicle according to the invention. The hybrid electric vehicle comprises, in the usual manner, an internal combustion engine, an electric motor, and a foot pedal, which, however, in this case—at an angular position of approximately 50% of its structurally determined end position—has an additionally activatable pressure point. The hybrid electric vehicle further comprises a control device in the form of a push button to put the vehicle into a primarily electric-motor driving mode.

[0013] When the vehicle is started from a standstill (0 km / h) in this driving mode, it initially assumes a first operating state (1), from which it transitions through a second operating state (2) to a third operating state (3) as the accelerator pedal (20) is increasingly depressed until it reaches its maximum speed (vmax). This process will now be illustrated by the Fig. 2 examined in detail.

[0014] The hybrid electric vehicle operates in its first operating state (1) purely on electric power and is limited to a speed of 55 km / h, which provides the vehicle with a long electric range in urban areas. If the pressure point activated in the first operating state (1) is exceeded – for example, during an overtaking maneuver – the combustion engine is started and the speed limit is lifted. This transition is in Fig. 1 and Fig. 2 marked with reference numeral 12 and puts the hybrid electric vehicle into its second operating state (2), while the pressure point initially remains activated (technically: “extended”).

[0015] When the hybrid electric vehicle exceeds a speed of 70 km / h in the second operating state (2), the pressure point is deactivated (technically: "retracted"). This state transition is in Fig. 1 and Fig. 2, marked with reference numeral 23, now puts the hybrid electric vehicle into its third operating state (3). In this third operating state (3), the vehicle is also operated using the internal combustion engine; it is therefore particularly suitable for use in rural areas.

[0016] If the hybrid electric vehicle falls below 55 km / h again in the second operating state (2) or third operating state (3), the hybrid electric vehicle is returned to the first operating state (1), so that both the speed limiter and – if necessary – the pressure point are reactivated. The corresponding state transitions are only in Fig. 1 marked with reference numbers 21 and 31 respectively.

Claims

[1] Method (10) for controlling a hybrid electric motor vehicle with a foot pedal (20), having the following features: - the hybrid electric vehicle alternately assumes a first operating state (1), a second operating state (2) or a third operating state (3), - the hybrid electric vehicle operates in the first operating state (1) purely on electric motor power, - the hybrid electric vehicle operates at least partially in the second operating state (2) and third operating state (3) using its internal combustion engine and - if a predetermined pressure point of the accelerator pedal (20) is mechanically overcome in the first operating state (1), the hybrid electric vehicle is put into the second operating state (2), characterized by the following characteristics: - Driving in the first operating state (1) is limited to a first driving speed of 55 km / h, - if the hybrid electric vehicle falls below the first driving speed in the second operating state (2) or third operating state (3), the hybrid electric vehicle is returned to the first operating state (1), - if the hybrid electric vehicle exceeds a second driving speed of 70 km / h in the second operating state (2), the hybrid electric vehicle is switched to the third operating state (3), - the first operating state (1) and the second operating state (2) are selectively deactivated by means of a button on the hybrid electric vehicle and - the pressure point is activated in the first operating state (1) and second operating state (2) and deactivated in the third operating state (3). [2] Hybrid electric vehicle, characterized by the following characteristics: - the hybrid electric vehicle comprises an internal combustion engine, an electric motor and a driving foot lever (20) with an activatable pressure point and - the hybrid electric motor vehicle is adapted to be controlled in a method (10) according to claim 1. [3] Hybrid electric motor vehicle according to claim 2, characterized by the following characteristic: - the hybrid electric vehicle further comprises a control device, in particular a button, for deactivating the first operating state (1) and second operating state (2). [4] Hybrid electric motor vehicle according to claim 2 or 3, characterized by the following characteristic: - the driving foot lever (20) is configured such that the pressure point is overcome when the driving foot lever (20) is actuated by more than 50%. [5] Computer program which is configured to perform all steps of a method (10) according to claim 1. [6] Machine-readable storage medium with a computer program stored thereon according to claim 5.

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