AT515193B1 - Method for operating a hybrid vehicle - Google Patents

Abstract

The invention relates to a method for operating a hybrid vehicle (1) having at least one electric machine (EM) and at least one internal combustion engine (ICE), which is at least in a first operating range (B1) when the internal combustion engine (ICE) is stationary by the electric machine (EM). is driven, wherein in at least a second operating range (B2), the internal combustion engine (ICE) is operated, which is supplied below a minimum operating temperature heat energy from a latent heat storage (4). In order to reduce fuel consumption and emissions, it is provided that a remaining operating time (ΔtR) of the electric machine (EM) in the first operating range (B1) is estimated as a function of at least one influencing variable and the beginning (tH) of supplying heat energy from the latent heat accumulator ( 4) to the internal combustion engine (ICE) as a function of the remaining operating time (.DELTA.tR) of the electric drive machine (EM).

Description

The invention relates to a method for operating a hybrid vehicle having at least one electric machine and at least one internal combustion engine, which is driven by the electric machine at least in a first operating range when the internal combustion engine is stationary, the internal combustion engine being operated in at least one second operating range. which is supplied below its operating temperature heat energy from a latent heat storage. Furthermore, the invention relates to a hybrid vehicle, with at least one electric machine and at least one internal combustion engine which is drivable by the electric machine at least in a first operating range with the internal combustion engine, wherein in at least a second operating range, the internal combustion engine is operable, which below a minimum operating temperature heat energy can be supplied from a latent heat storage, for carrying out the method.

From EP 1 172 538 A2 an internal combustion engine with a heat storage is known, wherein the internal combustion engine is preheated by hot water from the heat storage device. The electronic control unit of the internal combustion engine determines the necessary preheating time on the basis of the cooling water temperature of the internal combustion engine to automatically start the internal combustion engine after completion of the preheating.

A storage device for heat from a warm coolant for a hybrid vehicle is disclosed in JP 2001-065384 A. This storage means for heat of a coolant recovers some coolant heated by the engine after the engine has warmed up and stores it in a heat storage tank as a warm coolant. The warm coolant heat storage device then replaces some engine coolant with the coolant stored in the heat storage tank during a cold start from the engine to heat the engine. This makes it possible to improve the cold start capability of the internal combustion engine and to reduce the exhaust emissions.

EP 1 199 206 A2 describes a hybrid vehicle which is driven by either an internal combustion engine or an electric motor. In a latent heat storage at least a portion of the cooling water of the engine is kept warm and supplied before the start of the internal combustion engine this.

From AT 506272 A a method for operating an electric vehicle is known in which a power generating device is activated from a defined state of charge of the electrical energy storage. The power generating device is designed for a mean power demand of the electric drive machine at a defined continuous speed of the electric vehicle in the plane, the power generating device is activated before reaching a lower technical operating limit of the state of charge of the electric energy storage at a defined Einschaltladezustand, which is such that in relation to the lower technical operating limit, an energy reserve remains in the electrical energy storage in order to cover peak output. The Einschaltladezustand can be set flexibly depending on a destination and / or a planned route.

JP 2008-201165 A describes a control unit for a hybrid vehicle, wherein the switch-on of the engine depending on the state of charge of the energy storage is determined based on the recorded data of completed rides and due to the demonstrated driving characteristics of an identified driver.

AT 507 916 B1 describes a method for operating an electric vehicle which has at least one electric drive machine, at least one electrical energy store, and at least one power generating device formed in particular by a range extender, the current generating device depending on the state of charge of the electrical energy store and the route is activated. Starting from a reference point which corresponds to a starting point of the route, all possible routes are simulated within a defined viewing horizon. For each of the simulated travel routes, a switch-on point in time of the power generation device is prospectively determined, so that a defined charge state of the energy storage device is maintained when the viewing horizon is reached.

In a hybrid vehicle, the operating range in which a purely electrical operation is possible limited by the state of charge of the electrical energy storage. If the state of charge of the electrical energy store falls below a defined threshold, the internal combustion engine of the hybrid vehicle is activated in order to drive the hybrid vehicle alone or together with the electric drive machine, or to provide the electrical energy for driving the electric drive machine together with an electric generator. The cold start of the internal combustion engine is associated with increased emissions and increased fuel consumption.

It is known to preheat an internal combustion engine by retrieving the heat energy from the latent heat storage. In vehicles with conventional drive via an internal combustion engine but the time at which the heating of the internal combustion engine is triggered by the latent heat storage, can not be planned. When starting the engine, it is already too late to retrieve the heat from the latent heat storage, but when switching on the ignition, it is actually still too early.

The object of the invention is to avoid the disadvantages mentioned and to reduce emissions and fuel consumption in a hybrid vehicle.

According to the invention, this is achieved by estimating a remaining operating time of the electric machine in the first operating range as a function of at least one influencing variable, and by starting the supply of thermal energy from the latent heat accumulator to the internal combustion engine as a function of the remaining operating time of the electric drive machine.

The estimation of the remaining operating time of the electric machine via an electronic control unit, such as a motor control unit or a hybrid control unit. By the method according to the invention, the internal combustion engine can be optimally tempered at the start time, which enables a reduction of emissions and fuel consumption. The formulation according to which the beginning of the supply of the heat energy takes place as a function of the remaining operating time of the electric drive machine is thus to be understood as meaning that a balance between the best achievable operating temperature of the internal combustion engine with remaining operating time of the electric drive machine is to be achieved.

Preferably, the beginning of the supply of heat energy from the latent heat storage in dependence on the temperature of the internal combustion engine and / or a cooling and / or lubricating medium of the internal combustion engine. For determining the temperature of the internal combustion engine and / or a cooling and / or lubricating medium of the internal combustion engine, the control unit communicates with the control unit with at least one temperature sensor connected to the internal combustion engine and / or to the cooling and / or cooling medium.

From the current temperature of the internal combustion engine, the amount of heat to be supplied depends. Only when the determined temperature is below a defined minimum operating temperature of the internal combustion engine, it is necessary to retrieve the heat energy of the latent heat storage and preheat the engine.

In the context of the present invention it is provided that at least one influencing variable from the group of current state of charge and / or capacity of the vehicle battery; average power consumption of the electric machine for a reference route already traveled; Power consumption of currently switched on consumer; current vehicle weight; Driving style and / or driver type; Topography, weather conditions, road conditions, current traffic situation of the preceding route; Selected day and / or season and the control unit is provided via at least one information source available and the remaining operating time of the electric machine in the first operating range as a function of at least this factor is determined by means of a calculation model by the control unit.

The remaining operating time of the electric machine is essentially limited by the state of charge or the capacity of the vehicle battery supplying the electric machine. For the estimation of the remaining operating time, the current state of charge and / or the capacity of the vehicle battery is determined via at least one voltage and / or current measuring device and the remaining operating time is preferably estimated on the basis of an average power consumption of the electric machine for an already traveled reference path. For estimating the capacity of the vehicle battery, a method known, for example, from AT 512 745 A can be used.

The driving style can be analyzed from acceleration, deceleration, average speed and peak speed information recorded on acceleration, speed and pedal travel sensors for already-traveled sections. The result of this analysis shows, for example, whether predominantly a sporting or economical driving style is present, or whether it is a sporty or economical driver type.

Information about the topography of preceding sections can be found from internal or external information storage such as navigation devices, or over the Internet. The current road conditions, the current traffic situation and weather conditions can most easily be retrieved via an existing Internet connection from an information server. Internet access for the control unit is thus advantageous.

In the electronic control unit of the internal combustion engine or in the hybrid control unit - as a function of at least one of the above influencing variables - estimated the remaining operating time of the electric drive machine and thus determines a planned switch-on of the internal combustion engine. Depending on the temperature of the internal combustion engine, an optimum electrical preheating time of the latent heat accumulator is calculated and, depending on the planned start of operation of the internal combustion engine, the beginning of the supply of heat energy from the latent heat accumulator to the internal combustion engine is determined. The supply of heat energy to the internal combustion engine can be done indirectly via a lubricating or cooling medium, or directly.

At the end of the electrical heating process, the internal combustion engine can already be operated at least partially warm. This leads to a significant reduction in the friction torque, and thus the fuel consumption and emissions.

To achieve the object, a hybrid vehicle is provided according to the invention, in which a remaining operating time of the electric machine by a control unit in response to at least one influencing variable can be estimated and the beginning of supplying heat energy from the latent heat storage to the internal combustion engine as a function of the remaining operating time the electric drive machine is adjustable. Preferably, the beginning of the supply of heat energy from the latent heat storage in dependence on the temperature of the internal combustion engine and / or a cooling and / or lubricating medium of the internal combustion engine is adjustable by the control unit, wherein for determining the temperature of the internal combustion engine and / or a cooling and / or Lubricating medium of the internal combustion engine is at least one connected to the internal combustion engine and / or with the cooling and / or cooling medium temperature sensor connected to the control unit.

At least one influencing variable from the group of current state of charge and / or capacity of the vehicle battery; average power consumption of the electric machine for a reference route already traveled; Power consumption of the currently switched on power consumers, current vehicle weight, driving style and / or driver type, topography, weather conditions, road conditions, current traffic situation of the route ahead, day and / or season can be available via at least one information source of the control unit and the remaining operating time of the electric Machine in the first operating range as a function of at least this influencing variable by means of a computer model by the control unit be determined.

Furthermore, to determine the current state of charge and / or the capacity of the vehicle battery, the average power consumption of the electric machine for an already driven reference distance and / or the current power consumption of the power consumer of the hybrid vehicle, the control unit with at least one current and / or voltage sensor be connected as a source of information. For determining the driving style and / or the driver type, the control unit can advantageously be connected to at least one acceleration sensor and / or pedal travel sensor as information source.

In the context of the invention, it is further provided that for the determination of information about daytime and / or season, weather conditions, topography, road conditions and / or traffic situation - the control unit with at least one in-vehicle or external information storage is connected or connectable as a source of information ,

The invention will be explained in more detail below with reference to FIG.

1 shows a hybrid vehicle for carrying out the method according to the invention; FIG. 2 shows the method according to the invention in a block diagram; and [0029] FIG. 3 shows the phase of warming up and starting the internal combustion engine over time t applied.

The hybrid vehicle 1 has at least one connected to a vehicle battery 2 electric machine EM for driving and an internal combustion engine ICE, which may be arranged in parallel or serially in the drive train 3 of the hybrid vehicle 1. Heat energy can be stored via a latent heat accumulator 4 and fed to the internal combustion engine ICE before the starting process, the internal combustion engine ICE being heated directly or via a lubricating or cooling medium 6. In the context of the present disclosure, a latent heat store 4 is understood to mean a device which allows the storage of heat in a vehicle in any desired form. The latent heat storage 4 has, for example, a phase change material as a storage medium, which releases previously absorbed amounts of heat as heat of crystallization again. The latent heat storage 4 may optionally be heated by an electric heater 5, wherein the electric heater 5 is powered by the vehicle battery 2.

The temperature of the internal combustion engine ICE, the lubricating medium and / or the cooling medium 6 is measured via at least one temperature sensor 7.

The control unit ECU - for example, a motor or hybrid control unit - are various sources of information for obtaining influencing variables for the calculation of the remaining operating time available, namely voltage and / or current measuring devices 8, 9, at least one internal information storage 10, at least one external Information memory 11, at least one acceleration and / or pedal travel sensor 12 and at least one force or displacement transducer 13.

The voltage and / or current measuring devices 8, 9 are used to determine the state of charge of the vehicle battery 2 and the power consumption of all relevant power consumers of the hybrid vehicle 1. The internal information memory 10 can provide information about the day and season, the topography of the route, etc. include. Current data on weather conditions, road conditions, traffic conditions, construction sites, etc. can be accessed via the external information memory 11. The external information storage 11 can be queried via a wireless communication path via the Internet. The data of

Pedal way and / or acceleration sensors 12 serve - after evaluation and classification by the electronic control unit ECU - in a known manner for determining the driving style and / or the driver type (not part of the invention). About force or displacement transducer 13 on the vehicle suspension or on the vehicle suspension, the current vehicle weight can be determined.

The method is shown schematically in FIGS. 2 and 3.

In step 20, the electric machine EM is activated in a first operating range B1 of the hybrid vehicle 1 and drives the hybrid vehicle 1 via the drive train 3. The internal combustion engine ICE is deactivated.

In step 21, the remaining operating time EtR of the electric machine EM is estimated by an algorithm. The estimation of the electrical operating time tR is effected as a function of the following parameters: current charge state SOC and / or capacity of the vehicle battery 2; Current or anticipated power consumption lv of power consumers - e.g. Heating, air conditioning, etc .; • average power consumption IEm of the electric machine EM for a reference route already traveled; • Driving style and / or driver type FT; • weather conditions WT - weather, visibility, precipitation, outside temperature; • Daytime TC daylight, darkness; • topography TP; • road condition SZ- dry, wet, icy; • Traffic situation VL traffic incidents, accidents, construction sites, diversions; • vehicle weight G - can be measured, for example, by means of load cells on the suspension or transducer on the spring struts; All these influencing factors affect the remaining operating time EtR of the pure electric drive by the electric machine EM.

On the basis of the determined remaining operating time EtR, a planned starting time t0 of the internal combustion engine ICE is determined in step 22.

In step 23, the heating time of the internal combustion engine ICE ICE is determined by the latent heat storage 4 due to the current heat capacity of the latent heat accumulator 4 and the current temperature Tice of the internal combustion engine ICE or a cooling or lubricating medium of the internal combustion engine ICE and in step 24 the beginning tH [0041] If the determined warm-up time EtH is smaller than the remaining operating time EtR, then the beginning tH of supplying the heat energy from the latent-heat storage 4 to the internal combustion engine ICE is selected such that the heat energy is supplied from the latent heat storage 4 to the internal combustion engine ICE. in that, at the start time t0, the internal combustion engine ICE has reached a defined minimum operating temperature and, at the time tH, starts to warm the internal combustion engine ICE (step 25). Otherwise, in a step 26 with the supply of heat energy from the latent heat storage to the internal combustion engine ICE started immediately to ensure the best possible preheating of the internal combustion engine ICE. In both cases, the internal combustion engine ICE is started as planned at the start time t0 (step 27). After completion of the start phase At0 of the internal combustion engine ICE can - in the case of a parallel hybrid drive - to pass the opening of the second operating range B2 of the drive to the internal combustion engine ICE and the electric machine EM are disabled. In the case of a serial or mixed hybrid drive, the electric machine EM remains activated and connected to the drive train 3.

The charging of the latent heat accumulator 4 with heat energy can be done during the second operating range B2 by waste heat of the internal combustion engine ICE. If the driving profile does not allow storage of the heat energy in the second operating range B2, then the latent heat accumulator 4 can also be charged with thermal energy via the local power grid by means of the heating device 5 if the plug-in functionality is present. Alternatively, the latent heat accumulator 4 can also be charged during or after the electric ferry operation in the first operating range B1, in particular if the state of charge SOC of the vehicle battery 2 is high, since then neither recharging via the mains nor activation of the internal combustion engine ICE is likely.

In Fig. 3, a phase of the switching from the first operating range B1 to the second operating range B2 is plotted over the time t, wherein A denotes the current time, on the basis of the remaining operating time AtR of the electric machine EM in the first operating range B1 is determined.

Claims (10)

claims 1. A method for operating a hybrid vehicle (1) having at least one electric machine (EM) and at least one internal combustion engine (ICE) which is driven by the electric machine (EM) at least in a first operating range (B1) when the internal combustion engine (ICE) is at a standstill , wherein in at least a second operating range (B2) the internal combustion engine (ICE) is operated, which is supplied below a minimum operating temperature heat energy from a latent heat storage (4), characterized in that a remaining operating time (EtR) of the electric machine (EM) in first operating range (B1) is estimated as a function of at least one influencing variable and the beginning (tH) of supplying heat energy from the latent heat accumulator (4) to the internal combustion engine (ICE) as a function of the remaining operating time (AtR) of the electric drive machine (EM). 2. The method according to claim 1, characterized in that the beginning (tH) of the supply of heat energy from the latent heat accumulator (4) in dependence of the temperature (Tice) of the internal combustion engine (ICE) and / or a cooling and / or lubricating medium (6 ) of the internal combustion engine (ICE) takes place. 3. The method according to claim 1 or 2, characterized in that at least one influencing variable from the group of current state of charge (SOC) and / or capacity of a vehicle battery (2); average power consumption (IEm) of the electric machine (EM) for an already traveled reference path; Current consumption (lv) currently switched on consumer, current vehicle weight (G), driving style and / or driver type (FT), topography (TP), weather conditions (WT), road conditions (SZ), current traffic situation (VL) of the preceding route, day and / or season (TZ) is selected and the remaining operating time (AtR) of the electric machine (EM) in the first operating range (B1) is determined as a function of at least this influencing variable by means of a computer model. 4. hybrid vehicle (1), with at least one electric machine (EM) and at least one internal combustion engine (ICE), which at least in a first operating range (B1) with a stationary internal combustion engine (ICE) by the electric machine (EM) can be driven, wherein in at least a second operating range (B2), the internal combustion engine (ICE) is operable, which is supplied below a minimum operating temperature heat energy from a latent heat storage (4) for performing the method according to one of claims 1 to 3, characterized in that a control unit (ECU ) of the hybrid vehicle (1) is set to estimate a remaining operating time (AtR) of the electric machine (EM) as a function of at least one influencing variable and the beginning (tH) of supplying heat energy from the latent heat store (4) to the internal combustion engine (ICE) depending on the remaining operating time (AtR) of the electric drive machine (EM) SET lbar is. 5. hybrid vehicle (1) according to claim 4, characterized in that the beginning (tH) of supplying heat energy from the latent heat accumulator (4) in dependence of the temperature (T | Ce) of the internal combustion engine (ICE) and / or a cooling and / or lubricating medium (6) of the internal combustion engine (ICE) by the control unit (ECU) is adjustable, wherein for determining the temperature (Tice) of the internal combustion engine (ICE) and / or a cooling and / or lubricating medium (6) of the internal combustion engine (ICE ) at least one with the internal combustion engine (ICE) and / or with the cooling and / or cooling medium (6) connected to the temperature sensor (7) is connected to the control unit (ECU). 6. hybrid vehicle (1) according to claim 4 or 5, characterized in that at least one influencing variable from the group of current state of charge (SOC) and / or capacity of the vehicle battery (2); average power consumption (IEm) of the electric machine (EM) for an already traveled reference path; Electricity consumption (lv) of currently switched on power consumers, current vehicle weight (G), driving style and / or driver type (FT), topography (TP), weather conditions (WT), road conditions (SZ), current traffic situation (VL) of the preceding route, day and / or season (TZ) via at least one information source of the control unit (ECU) is available and the control unit (ECU) is adapted to the remaining operating time (AtR) of the electric machine (EM) in the first operating range (B1) in dependence of at least this Determine influence quantity by means of a calculation model. 7. hybrid vehicle (1) according to one of claims 6, characterized in that for determining the current state of charge (SOC) and / or the capacity of the vehicle battery (2), the average power consumption (IEm) of the electric machine (EM) for an already traveled reference path and / or the current power consumption (lv) of the power consumers of the hybrid vehicle (1) the control unit (ECU) with at least one current and / or voltage sensor (8, 9) is connected as an information source. 8. hybrid vehicle (1) according to claim 6 or 7, characterized in that for determining the current vehicle weight (G) of the hybrid vehicle (1) the control unit (ECU) with at least one force or displacement transducer (3) is connected as an information source. 9. hybrid vehicle (1) according to one of claims 6 to 8, characterized in that for determining the driving style and / or the driver type (FT), the control unit (ECU) with at least one acceleration sensor and / or pedal travel sensor (12) is connected as an information source , 10. hybrid vehicle (1) according to one of claims 6 to 9, characterized in that for the determination of information about daytime and / or season (TZ), weather conditions (WT), topography (TP), road condition (SZ) and / or Traffic situation (VL) - the control unit (ECU) with at least one in-vehicle or external information storage (10, 11) connected as an information source or is connectable.