METHOD AND SYSTEM FOR POWER ENGINE CONTROL

Abstract

Methods for steering a stationary vehicle, comprising the following: Automatic prevention of the shutdown of a vehicle engine at idle based on an ambient temperature and a determination of whether the vehicle is located in an enclosed space or an open space, wherein the determination is based on an input from one or more of a navigation system coupled to the vehicle, a location sensor, a radio signal and a manifold airflow sensor of the vehicle.

Description

Area

[0001] The present application relates to methods and systems for controlling the shutdown of a vehicle engine while idling. Background and Summary

[0002] US 2008 / 0009988A1 describes a location-determining method and system for controlling an engine to automatically regulate the cabin temperature in a parked vehicle equipped with a heating / cooling device, wherein the method involves determining the current location of the vehicle using a satellite navigation system, retrieving location-specific parameters of engine operation from memory, and automatically controlling the engine's idle speed in accordance with local law to enable the heating / cooling device to maintain a desired cabin temperature.

[0003] DE 10 2008 064 018 A1 describes a method for changing the operating state of a vehicle's internal combustion engine, encompassing deactivation and / or activation, in which at least one piece of environmental information is used as an influencing factor for changing the engine's operating state. This at least one piece of environmental information comprises spatially referenced data. Furthermore, the invention relates to a device for changing the operating state of the vehicle's internal combustion engine.

[0004] US 7 027 912 B1 describes a method and system for controlling an engine to maintain a comfortable cabin temperature in a vehicle equipped with an engine, battery, and heating / cooling device, including determining an acceptable range of cabin temperatures, monitoring cabin and outside air temperatures, controlling the automatic starting of the vehicle's engine when both temperatures are outside the acceptable range, and running the engine only to the minimum extent necessary to keep the cabin temperature within the acceptable range.

[0005] US 2009 / 0171548A1 describes a method for operating a vehicle in which, during the operation of the engine, a control signal sent from outside the vehicle is received, containing instructions for changing a vehicle operating parameter and for changing the vehicle operating parameter according to the instructions.

[0006] German patent DE 10 2008 050 853 A1 describes a start / stop device for a vehicle. The start / stop device comprises a detection unit for recording the vehicle's operating state and the wiper frequency of the vehicle's windshield wiper system, as well as a control unit that is coupled to the detection unit and the vehicle's engine control unit. The control unit automatically starts or stops the drive motor via the engine control unit, depending on the detected operating state of the vehicle and the detected wiper frequency.

[0007] German patent DE 10 2005 040 143 A1 describes a method for predicting the starting capability of a motor vehicle based on future weather forecasts. Existing systems for determining the starting capability of motor vehicles or starter batteries are extended by a telematics service for temperature prediction. Based on the predicted temperature, a starting capability prediction is calculated using a temperature-integrated state-of-charge sensor of the starter battery, and a corresponding warning is issued if starting capability is at risk.

[0008] DE 603 ​​07 013 T2 describes a control system for the commissioning of a vehicle engine with an idle stop function and an electronic key system.

[0009] DE 10 2007 009 870 A1 describes a method for controlling an automatic shutdown and / or start-up process of an internal combustion engine in a motor vehicle by means of a start-stop device, by which, after the internal combustion engine has been started by a person and the motor vehicle has been driven, the internal combustion engine is automatically shut off when the motor vehicle comes to a stop, if predefined shutdown conditions are met by corresponding influencing factors, and / or by which an automatically shut-off internal combustion engine is automatically switched on when predefined switch-on conditions are met by corresponding influencing factors, characterized in that an activity state of a vehicle speed control system is taken into account for an evaluation of shutdown conditions and / or switch-on conditions.

[0010] US Patent 2011 / 0224843A1 describes a method for remotely starting a vehicle using a remote device. The method includes: receiving an initial temperature associated with the vehicle; evaluating the initial temperature at the remote device; and initiating the vehicle start by generating a signal to the vehicle based on the start request and the initial temperature.

[0011] US Patent 2004 / 0262995A1 describes an engine control system with a microprocessor-based engine control module (ECM) that automatically starts an internal combustion engine when any of the following enable signals indicate low battery voltage, low cabin temperature, and / or low engine temperature. The system also includes safety measures that override the automatic engine start. For example, the vehicle will not start automatically if a vehicle speed is detected, if the parking brake is not engaged, if the ignition key is not in the "on" position, or if the hood is open. Additionally, the system is configured not to start if the fuel level is low.

[0012] US 2010 / 0 138 139 A1 describes a procedure for adjusting thermal comfort in a vehicle when the engine is stopped and started. The procedure defines key conditions, primarily related to engine coolant temperature, interior temperature, the risk of windshield fogging, and the risk of odors in the air conditioning system's evaporator. These conditions limit engine idle time. This limitation can be implemented by prohibiting engine shutdown or by requiring an engine restart.

[0013] DE 10 2007 057 216 A1 describes a system for a vehicle, in particular for a land or water vehicle, with a drive motor for propelling the vehicle and a wireless remote control device that serves at least to start the drive motor, wherein a control device is provided that is suitable for receiving at least one signal generated by the remote control device for starting the drive motor and for causing the drive motor to start on the basis of the received signal.

[0014] In recent years, vehicles have been configured with new driver ignition interfaces to simplify vehicle operation. Previous key-based interfaces, for example, have been replaced by keyless or smart key interfaces. While previous key-based interfaces required the driver to start or stop the engine by inserting or removing a key (such as an active key) into or from the ignition system, newer interfaces allow the engine to be started or stopped by pressing a start / stop button and / or based on the presence of a passive key (such as a smart key or electronic key fob) within a predetermined distance of the vehicle.

[0015] Without a physical device (such as an active key) that must be inserted into or removed from the ignition system to start or stop the engine, a driver could inadvertently leave the vehicle with the engine idling. Recent advances in engine technology, which have made vehicle engines quieter, further increase the likelihood of a driver leaving the vehicle with the engine running. To address this problem, vehicle control systems can be configured to automatically shut off the engine when idling, for example, after a specified period of idling time.

[0016] However, the inventors have identified potential problems with vehicles equipped with such keyless interfaces. For example, a driver might temporarily exit the vehicle and intentionally leave the engine idling to maintain a desired cabin environment and ensure driving comfort upon returning. This can be particularly important during inclement weather. If the engine is prematurely stopped by the vehicle's control system while idling, the desired cabin environment cannot be maintained, and the driver's experience upon returning to the vehicle may be negatively impacted.

[0017] The object of the present invention is therefore to provide improved methods for controlling a vehicle at a standstill and a corresponding vehicle system.

[0018] This problem is solved by the subject matter of the independent claims. Preferred embodiments of the present invention are the subject matter of the dependent claims.

[0019] In one example, the above problem can be addressed, at least partially, by a method for controlling a stationary or stopped vehicle. In one embodiment, the method includes automatically preventing the shutdown of an engine while idling, based on the vehicle's location and ambient temperature conditions. In this way, the automatic shutdown of an engine while idling can be overridden under selected conditions, such as during cold weather when the vehicle is parked outdoors.

[0020] In one example, a driver might intentionally leave a vehicle stationary with the engine running. That is, the vehicle might be temporarily parked with the engine idling to warm up the engine and the vehicle. A vehicle control system can use one or more location sensors, onboard navigation equipment, temperature sensors, humidity sensors, oxygen sensors, etc., to determine the vehicle's location and further determine whether the vehicle is in a substantially enclosed space or an open space. For example, a control unit can determine whether the vehicle is parked in a substantially enclosed space or an open space based on a change in an environmental condition (such as temperature or humidity), as estimated over a period of time while the vehicle is stationary.In response to the vehicle being parked in an open space, such as an open parking lot, the vehicle control system may delay the automatic shutdown of the engine while idling, anticipating the driver's imminent return. The amount of delay may be based on environmental conditions, such as the ambient temperature of the location. For example, during cold weather conditions, the amount of delay may be increased to maintain a warm cabin temperature inside the vehicle or to heat an exhaust aftertreatment device, such as a catalytic converter. Conversely, in response to the vehicle being parked in a substantially enclosed space, such as an indoor garage, the vehicle control system may automatically shut off the engine while idling, anticipating the driver's imminent return.

[0021] By adjusting the idle shutdown of a vehicle's engine based on its geographical location and environmental conditions, improved driver comfort can be achieved, thereby enhancing the driver's driving experience. Furthermore, vehicle emissions and wasteful fuel consumption can be reduced.

[0022] Naturally, the above summary is intended to introduce, in simplified form, a selection of concepts that are further described in the detailed description. It is not intended to identify any key or essential features of the claimed subject matter, the scope of which is defined solely by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that overcome any disadvantages specified above or in any part of this disclosure. Brief description of the drawings Fig. Figure 1 represents an example vehicle system. Fig. Figure 2 represents example ignition interfaces used in the vehicle system of Fig. 1 may be included. Fig. Figure 3 represents an example design of an internal combustion engine. Fig. Figure 4 represents a high-level flowchart for setting the shutdown of a power engine in idling based on the location and environmental conditions of a parked vehicle. Fig. Section 5 represents a high-level flowchart for determining the location of a stationary vehicle based on the output from one or more vehicle sensors. Detailed description

[0023] The following description refers to systems and methods for operating a vehicle with an ignition interface that is keyless or operated with a passive key, such as in the vehicle system of Fig. Figures 1-3 show that, under conditions where a driver has left the vehicle stationary with the engine idling, automatic engine shutdown can be set based on the location where the vehicle is parked and the ambient conditions (e.g., temperature) of that location. An engine control unit can be configured to execute a control routine, such as the routine of Fig. 4. To perform an operation that automatically shuts off the engine when idling if the vehicle is parked in an enclosed space, such as an indoor parking lot. However, if the vehicle is parked in an open space, such as an outdoor parking lot, and the external conditions are harsh, the automatic shutdown can be delayed to allow the cabin to reach a desired temperature for the driver upon their return. The control unit can infer whether the vehicle's location is an enclosed or open space based on changes in an environmental condition (e.g., a change in temperature or humidity) or an engine operating condition (e.g., a change in a commanded exhaust-air / fuel ratio) over a period of time while the driver is away from the vehicle. Fig. 5) Alternatively, the location can be derived from vehicle location sensors and navigation systems. By setting the automatic engine shutdown at idle based on the location and ambient temperature, driver comfort can be improved while reducing exhaust emissions and fuel waste.

[0024] Fig. Figure 1 represents a vehicle system 100 with an internal combustion engine 10 coupled to a transmission 44. The engine 10 can be started with an engine starting system 54 using a starter motor. The transmission 44 can be a manual transmission, an automatic transmission, or a combination thereof. The transmission 44 can include various components such as a torque converter, a final drive unit, a multi-gear gear set, etc. The transmission 44 is shown coupled to drive wheels 52, which can be in contact with a road surface.

[0025] In one embodiment, the vehicle system 100 can be a hybrid vehicle, wherein the transmission 44 can alternatively be driven by an electric motor 50. The motor can, for example, be a battery-powered electric motor (as shown), wherein the electric motor 50 is operated by energy stored in the battery 46. Other energy storage devices that can be used to operate the motor 50 include a capacitor, a flywheel, a pressure vessel, etc. An energy conversion device, here an inverter 48, can be configured to convert the DC voltage output of the battery 46 into an AC voltage output for use by the electric motor 50.The electric motor 50 can also be operated in a regenerative mode, that is, as a generator, to absorb energy from the vehicle's movement and / or from the engine and convert the absorbed energy into a form suitable for storage in the battery 46. Furthermore, the electric motor 50 can be operated as a motor or generator, as required, to increase or absorb the torque during a transition of the engine 10 between different combustion modes (e.g., during transitions between a spark ignition mode and a compression ignition mode).

[0026] When configured in hybrid form, the vehicle system 100 can operate in various modes, with the vehicle being powered by only the engine, only the electric motor, or a combination of both. Alternatively, support or mild hybrid modes can also be used, with the engine being the primary torque source and the electric motor selectively adding torque during specific conditions, such as during rapid acceleration. For example, during an "engine-on" mode, the engine 10 can be operated and used as the primary torque source to drive the wheels 52. During the "engine-on" mode, fuel can be supplied to the engine 10 from the fuel system 20 via a fuel tank. The fuel tank can hold multiple fuels, such as gasoline or fuel mixtures such as...a fuel with a range of alcohol concentrations (e.g., ethanol concentrations), including E10, E85, etc., and combinations thereof. In another example, the electric motor 50 can be operated during a "power engine off" mode to drive the wheels. The "power engine off" mode can be used during braking, at low speeds, while stopped at traffic lights, etc. In yet another example, during an "assist" mode, an alternative torque source can supplement and work in conjunction with the torque supplied by the power engine 10.

[0027] The vehicle system 100 can further comprise a control system 14. The control system 14 is shown receiving information from several sensors 16 (various examples of which are described here) and sending control signals to several actuators 81 (various examples of which are described here). The control system 14 can further comprise a control unit 12. The control unit can receive input data from the various sensors or buttons, process the input data, and trigger the actuators in response to the processed input data based on a command or code programmed therein, according to one or more routines. Example control routines are described here with regard to Fig. 4-5 described.

[0028] As an example, the sensors can include 16 different pressure, temperature, and humidity sensors. The vehicle system 100 can, for instance, include a temperature sensor 162, located on an external surface of the vehicle or within an air intake system connected to air outside the vehicle, for estimating an ambient air temperature. The vehicle system can further include one or more temperature sensors located inside the vehicle for estimating a temperature within the vehicle's cabin. A vehicle driver can provide an input regarding a desired cabin temperature via an interactive driver device 18 (e.g., a button, knob, or touchscreen) configured on a vehicle instrument panel 19.Based on the cabin temperature setting selected by the driver in relation to the estimated ambient temperature, a vehicle HVAC system (not shown) can be operated to heat or cool the cabin and create the requested level of cabin comfort. The vehicle system 100 may also include a humidity sensor 164, located on the exterior surface of the vehicle or within an air intake system connected to the air outside the vehicle, for estimating ambient humidity. Further sensors communicating with the control system 14 may include a fuel level sensor coupled to the fuel system 20, a manifold airflow sensor 122, and an exhaust gas sensor 128 (e.g., an exhaust oxygen sensor), as shown in [reference missing]. Fig. 3 further developed.

[0029] The vehicle system 100 can also include an on-board navigation system 17 (for example, a global positioning system) on the dashboard 19, with which the driver can interact. The navigation system can include one or more location sensors to assist in estimating the vehicle's location (e.g., geographic coordinates). In one example, the navigation system and the one or more location sensors can be configured to infer whether the vehicle is parked in an enclosed space, such as an indoor parking lot, or an open space, such as an outdoor parking lot or open-air parking structure. For example, the navigation system can position the vehicle within a parking structure using at least dead reckoning techniques and further utilize additional map information to determine whether the parking structure is located in an open or enclosed space.In another example, an open space can be inferred based on the presence of an unobstructed or open view of the sky at the vehicle's location. Conversely, an enclosed space can be inferred based on the presence of an obstructed view (or the absence of an open view) of the sky at the vehicle's location.

[0030] The instrument panel 19 may also include a driver ignition interface 15, through which the driver can set the ignition status of the vehicle's engine. In particular, the driver ignition interface may be configured to initiate and / or terminate the operation of the vehicle's engine based on driver input. For comparison purposes, driver ignition interfaces are referred to here as follows: Fig. 2 described. The comparison data may include interfaces that require a physical device, such as an active key, which must be inserted into the driver ignition interface to start the engine and turn on the vehicle, or removed to deactivate the engine and turn off the vehicle. However, various embodiments may include a passive key 40 that is communicatively coupled to the driver ignition interface. The passive key may be configured as an electronic key fob or as a smart key that does not need to be inserted into or removed from the ignition interface to operate the vehicle's engine. Rather, the passive key may need to be located inside or near the vehicle (e.g., within a threshold distance from the vehicle).In further comparative data, a start / stop button can be used additionally or optionally, which is manually pressed by the driver to start or stop the engine and to turn the vehicle on or off. Based on the configuration of the driver ignition interface, a driver can provide information regarding whether the engine is in a running or off state, and furthermore, whether the vehicle is in a running or off state.

[0031] The control unit 12 can also receive an indication of the ignition status of the power unit 10 from an ignition sensor (not shown) that is coupled to the driver's ignition interface. The control unit 12 can also communicate directly with the power unit 10 regarding its on / off status. The vehicle 100 can further include a key fob sensor 38 configured to receive input from the passive key 40. In particular, the key fob sensor 38 can remotely pair the vehicle 100 with the passive key 40, thereby enabling remote keyless entry into the vehicle 100 and / or remote keyless operation of the vehicle's power unit 10.During conditions where the driver leaves the vehicle unoccupied (with the passive key remaining in the driver's possession), the key fob sensor 38 can also be configured to provide information regarding the driver's proximity to the vehicle to the control unit 12. Based on the driver's proximity to the vehicle, automatic shutdown of a motor in idle mode can optionally be set, as shown in . Fig. 4 elaborated.

[0032] The control system 14 can be configured to send control signals to the actuators 81 based on input received from the sensors and the vehicle driver. The various actuators can include, for example, cylinder fuel injectors, an air intake throttle valve coupled to the engine intake manifold, a spark plug, etc. (as shown in Fig. 3 further developed).

[0033] If one now Fig. 2, various comparative data and an embodiment of a driver ignition interface are shown (such as the driver ignition interface 15 of the vehicle system of Fig. 1) In the comparison data and the illustrated embodiments, a state with the power engine engaged is specified for the control unit 12 based on the position of a slot in the vehicle's keyhole, the presence or absence of a passive key in the vehicle, and / or the position of a vehicle ignition start / stop button. An associated position sensor (not shown) can transmit the respective positions to the control unit. The illustrated example embodiments of a configuration with the power engine engaged can be used in hybrid-capable vehicle systems (as in Fig. (as shown in Figure 1), vehicle systems not capable of hybrid operation and / or push-button engine start. It should also be recognized that the states with the engine engaged are not directly equivalent to states with the vehicle engaged. For example, states with the engine engaged can occur in states with both the vehicle engaged and the vehicle disengaged.

[0034] Comparative data of a driver ignition interface in a state with the engine running are shown at 200. Here, an engine keyhole 202 can encompass a slot 203. By inserting a physical device, such as an active key, the position of the slot 203 can be changed between a first position 204, corresponding to a state with the vehicle off, a second position 206, corresponding to a state with the vehicle (and engine) running, and a third position 208, corresponding to a state with the starter engaged (or the engine running). To start the engine, a vehicle key can be inserted into the keyhole 202, and the slot 203 can initially be positioned in the third position 208 to initiate the operation of the engine starter.After the engine has started, the slot can be returned to the second position 206 to signal that the engine is running. After the engine has finished running, the vehicle can be switched off by moving the slot 203 to the first position 204. A state of the vehicle being switched off can be transmitted to the control unit by the slot 203 being in the first position 204, regardless of whether the key is in or out of the slot.

[0035] Further comparative data of a driver ignition interface in a state with the engine running are shown at 230. Here, an engine keyhole 212 can include a slot 213. By inserting a physical device, such as an active key, the position of the slot 213 can be changed between a first position 214, corresponding to a state with the vehicle off, and a second position 216, corresponding to a state with the vehicle running. An additional button 218 can be provided, which can be switched between a start position 220 and a stop position 222, in order to start or stop the engine accordingly.To start the engine, a vehicle key can be inserted into the keyhole 212, the slot 213 can be set to the second position 216, and the button 218 can be pushed to the start position 220 to start the engine. The engine can be stopped by pushing the button 218 to the stop position 222. After the engine has been switched off, a state with the vehicle switched off can be reached by moving the slot 213 to the first position 214. The state with the vehicle switched off can be transmitted to the control unit by the slot 213 being in the first position 214, regardless of whether the key is in the slot or removed.

[0036] An example embodiment of a driver ignition interface in a vehicle-start state is shown at 250. Here, instead of a vehicle keyhole and a physical device such as an active key that must be inserted into the keyhole, a passive key 252 (such as a smart key or an electronic key fob) can be used to indicate the presence of a driver in the vehicle to the control unit. In particular, if the passive key 252 is inside the vehicle or within a threshold distance of the vehicle (for example, as detected by a key fob sensor communicatively coupled to an electronic key fob), a vehicle-start state can be confirmed.An additional button 254 may be provided, which can be switched between a start position 256 and a stop position 258 to start or stop the engine accordingly, but can only be pressed if the passive key is inside the vehicle (or within a threshold distance of it). To start the engine, the passive key may be inside the vehicle or within a threshold distance of it, and button 254 may be moved to the start position 256. A state with the vehicle (and also the engine) switched off can be indicated by the presence of the passive key 252 inside the vehicle and button 254 being in the stop position 258.Alternatively, a state with the vehicle switched off can be indicated by the absence of the passive key from inside the vehicle (or the presence of the passive key beyond a threshold distance from the vehicle).

[0037] In one example, the driver may have started the engine by pressing button 254 and then parked the vehicle. While the vehicle is stationary with the engine running, the driver may exit the vehicle, for example, using the passive key 252. The vehicle may be unoccupied for the duration of the standstill, with the driver's proximity exceeding a certain threshold. During this state with the engine running, the vehicle control system (or an engine control module of the vehicle control system) may be configured either to automatically shut down the engine at idle or to extend the idle time before automatically shutting down the engine at idle based on at least one ambient temperature estimated over the duration of the standstill.The control system can further be configured to infer whether the vehicle is located in an enclosed or open space (e.g., based on the output of one or more temperature sensors estimating ambient temperature, humidity sensors estimating ambient humidity, oxygen sensors estimating a commanded air / fuel ratio or mass ratio, location sensors, on-board navigation systems, etc.) and automatically shut off the engine at idle based on this inference. As in . Fig. As detailed in section 4, the control system can, in particular, automatically switch off the engine when idling if the vehicle is in an enclosed space, while extending the idle time before automatically switching off the engine if the vehicle is in an open space.

[0038] Fig. Figure 3 represents an example embodiment of a combustion chamber or cylinder of the power engine 10 (of Fig. 1) The power unit 10 can receive control parameters from a control system with a control unit 12 and input from a vehicle driver 130 via an input device 132. In this example, the input device 132 comprises an accelerator pedal and a pedal position sensor 134 for generating a proportional pedal position signal PP. As another example, input regarding a state with the vehicle and / or power unit switched on can be received via the driver ignition interface 15, as previously described with reference to Fig. 1-2 discussed. The cylinder (here also referred to as "combustion chamber") 30 of the engine 10 can comprise combustion chamber walls 136, in which a piston 138 is arranged. The piston 138 can be coupled to a crankshaft 140, so that a reciprocating motion of the piston is converted into a rotary motion of the crankshaft. The crankshaft 140 can be coupled to at least one drive wheel of the passenger car via a transmission system. Furthermore, a starter motor can be coupled to the crankshaft 140 via a flywheel to enable the engine 10 to be started.

[0039] Cylinder 30 can receive intake air via a series of intake air passages 142, 144, and 146. Intake air passage 146 can be connected to other cylinders of the engine 10 in addition to cylinder 30. In some embodiments, one or more of the intake passages can include a charging device such as a turbocharger or supercharger. Fig. Figure 3 shows, for example, the engine 10 configured with a turbocharger, comprising a compressor 174 arranged between the inlet passages 142 and 144, and an outlet turbine 176 arranged along the outlet passage 148. The compressor 174 can be driven, at least partially, by the outlet turbine 176 via a shaft 180 when the charging device is configured as a turbocharger. In other examples, such as when the engine 10 is equipped with a supercharger, the outlet turbine 176 can be optionally omitted, with the compressor 174 being driven by a mechanical input from an engine or the engine itself. A throttle valve 20 with a throttle plate 64 can be provided along an inlet passage of the engine to modify the flow rate and / or pressure of the inlet air supplied to the engine cylinders.The throttle valve 20 can, for example, be located downstream of the compressor 174, as shown in . Fig. 3 shown, or alternatively it can be provided upstream of compressor 174.

[0040] The exhaust port 148 can receive exhaust gases from other cylinders of the engine 10 in addition to cylinder 30. An exhaust gas sensor 128 is shown coupled to the exhaust port 148 upstream of an exhaust gas purification device 178. The sensor 128 can be selected from various suitable sensors for providing an indication of the exhaust gas-air / fuel ratio, such as a linear oxygen sensor or UEGO (universal or wideband exhaust gas oxygen sensor), a dual-state oxygen sensor or EGO (as shown), a HEGO (heated EGO), a NOx, HC, or CO sensor. The exhaust gas purification device 178 can be a three-way catalytic converter (TWC), a NOx trap, various other exhaust gas purification devices, or combinations thereof.

[0041] The exhaust gas temperature can be estimated by one or more temperature sensors (not shown) arranged in the exhaust passage 148. Alternatively, the exhaust gas temperature can be derived based on engine operating conditions such as speed, load, air / fuel ratio (AFR), ignition timing, etc. Furthermore, the exhaust gas temperature can be calculated by one or more exhaust gas sensors 128. It can be seen that the exhaust gas temperature can alternatively be estimated by any combination of the temperature estimation methods listed here.

[0042] Each cylinder of the engine 10 can comprise one or more inlet valves and one or more exhaust valves. For example, cylinder 30 is shown with at least one inlet valve 150 and at least one exhaust valve 156 arranged in an upper region of cylinder 30. In some embodiments, each cylinder of the engine 10, including cylinder 30, can comprise at least two inlet valves and at least two exhaust valves arranged in an upper region of the cylinder.

[0043] The inlet valve 150 can be controlled by the control unit 12 via cam actuation through a cam actuation system 151. Similarly, the exhaust valve 156 can be controlled by the control unit 12 via a cam actuation system 153. The cam actuation systems 151 and 153 can each comprise one or more cams and can employ one or more cam profile switching (CPS), variable cam timing (VCT), variable valve timing (VVT), and / or variable valve lift (VVL) systems, which can be operated by the control unit 12 to modify the valve actuation. The position of the inlet valve 150 and the exhaust valve 156 can be determined by valve position sensors 155 and 157, respectively. In alternative embodiments, the inlet and / or exhaust valve can be controlled by electric valve actuation.For example, cylinder 30 can alternatively comprise an inlet valve controlled by electric valve actuation and an exhaust valve controlled by cam actuation, including CPS and / or VCT systems. In other embodiments, the inlet and exhaust valves can be controlled by a common valve actuator or a common valve actuation system, or by an actuator or actuation system with variable valve timing.

[0044] Cylinder 30 can have a compression ratio that is the ratio of the volumes when piston 138 is at bottom dead center to top dead center. Conventionally, the compression ratio is in the range of 9:1 to 10:1. However, in some examples where different fuels are used, the compression ratio can be increased. This can occur, for example, when using higher-octane fuels or fuels with a higher latent heat of vaporization. The compression ratio can also be increased when direct injection is used, due to its effect on engine knock.

[0045] In some embodiments, each cylinder of the engine 10 may include a spark plug 192 for initiating combustion. The ignition system 190 can supply a spark to the combustion chamber 30 via the spark plug 192 in response to an advance ignition signal SA from the control unit 12 under selected operating modes. However, in some embodiments, the spark plug 192 may be omitted, for example, if the engine 10 can initiate combustion by auto-ignition or by fuel injection, as may be the case with some diesel engines.

[0046] In some embodiments, each cylinder of the engine 10 can be configured with one or more injectors for supplying a knock-suppressing or pre-ignition suppressant fluid to it. In some embodiments, the fluid can be a fuel, with the injector also being referred to as a fuel injector. As a non-limiting example, cylinder 30 is shown with a fuel injector 166. The fuel injector 166 is shown directly coupled to cylinder 30 for the direct injection of fuel into it in proportion to the pulse width of a signal FPW received by the control unit 12 via an electronic driver 168. In this way, the fuel injector 166 accomplishes what is known as direct injection (hereinafter also referred to as "DI") of fuel into the combustion cylinder 30. Fig. Figure 3 shows the injector 166 as a side-mounted injector; it can also be positioned above the piston, for example, near the spark plug 192. Such a position can improve mixing and combustion when the engine is operated with an alcohol-based fuel, due to the lower volatility of some alcohol-based fuels. Alternatively, the injector can be positioned above and near the intake valve to improve mixing.

[0047] Fuel can be supplied to the fuel injector 166 from a high-pressure fuel system 20 comprising fuel tanks, fuel pumps, and a fuel distribution line. Alternatively, fuel can be supplied by a single-stage fuel pump at a lower pressure, in which case the timing of direct fuel injection during the compression stroke may be more limited than when a high-pressure fuel system is used. Although not shown, the fuel tanks may also include a pressure converter that provides a signal to the control unit 12. It can be seen that in an alternative embodiment, the injector 166 may be a port injector that supplies fuel to the intake port upstream of the cylinder 30.

[0048] As described above, shows Fig. 3 only one cylinder of a multi-cylinder engine. In principle, each cylinder can also include its own set of intake / exhaust valves, fuel injector(s), spark plug, etc.

[0049] Fuel tanks in fuel system 20 can hold fuels with different properties, such as different compositions. These differences can include varying alcohol content, octane rating, heat of vaporization, fuel mixtures, and / or combinations thereof. For example, fuels with different alcohol contents could include gasoline and ethanol or methanol. In another example, the engine could use gasoline as the primary fuel and an alcohol-containing fuel mixture, such as E85 (approximately 85% ethanol and 15% gasoline) or M85 (approximately 85% methanol and 15% gasoline), as the secondary fuel. Other alcohol-containing fuels could be a mixture of alcohol and water, a mixture of alcohol, water, and gasoline, and so on.

[0050] The control unit 12 is in Fig. 3 as a microcomputer with a microprocessor unit 106, input / output ports 108, an electronic storage medium for executable programs and calibration values, shown in this particular example as a read-only memory chip 110, a random access memory 112, a hold memory 114 and a data bus.The control unit 12 can receive various signals from sensors coupled to the engine 10, in addition to the signals discussed previously, including the intake air flow (MAF) measurement from the mass airflow sensor 122; the engine coolant temperature (ECT) from the temperature sensor 116, which is coupled to a cooling sleeve 118; a profile ignition pulse (PIP) signal from a Hall effect sensor 120 (or other type), which is coupled to the crankshaft 140; a throttle position (TP) signal from a throttle position sensor; a manifold absolute pressure (MAP) signal from sensor 124; the cylinder AFR from the EGO sensor 128; and anomalous combustion from a knock sensor. An engine speed signal (RPM) can be generated by the control unit 12 from the PIP signal. The manifold pressure signal MAP from a manifold pressure sensor can be used to provide an indication of a vacuum or pressure in the intake manifold.The control unit can also receive driver input and information regarding the ignition status of the engine from a driver ignition interface 15.

[0051] The read-only storage medium 110 can be programmed with computer-readable data representing instructions executable by the processor 106 to perform the procedures described below, as well as other variations that are expected but not specifically listed. Example routines are given here with reference to Fig. 4-5 described.

[0052] If one now Fig. Section 4, an example routine 400, is shown for setting the automatic shutdown of an engine at idle in a stationary vehicle based on each location of the vehicle and an ambient condition (for example, ambient temperature) at that location. In this way, wasteful engine idling can be limited when the vehicle is parked indoors and imminent vehicle operation is not expected, while allowing the engine to continue idling to create a desired cabin condition when the vehicle is parked outdoors and imminent vehicle operation is expected.

[0053] A 402 response can confirm that the vehicle is stationary with the engine running. For example, the driver's ignition interface can confirm that the engine is switched on (e.g., a keyhole slot is in the ON position and / or a start / stop button is in the START position) and idling while the vehicle is stationary. In one example, the vehicle may be unoccupied, and optionally, the driver's proximity to the vehicle can be determined. For example, the driver may possess a passive key (e.g., a smart key or electronic key fob) to operate the vehicle, and the driver's proximity to the vehicle (e.g.,Whether the driver is within or beyond a certain distance from the vehicle can be determined by the position of the passive key, as detected by a communicatively coupled key fob sensor. Alternatively, the driver could be inside the vehicle while the vehicle is stationary.

[0054] Error code 406 can confirm that no driver input was received for a period of inactivity. For example, if the vehicle is unoccupied, it can confirm that while the vehicle is stationary and the driver is away from the vehicle, the driver did not use the passive key to remotely shut down the engine (and / or the vehicle). Alternatively, if the vehicle is occupied, it can confirm that the driver did not press the accelerator and / or brake pedal while the vehicle is stationary.

[0055] After confirmation that no driver input has been received, the duration of the standstill can be estimated based on ambient operating conditions and / or a commanded engine-air / fuel ratio. For example, the duration could be the time the driver is away from the vehicle, such as more than one threshold distance. Alternatively, the duration could be the time the driver is inside the vehicle but has not provided any driver input. For example, the driver might have fallen asleep inside the stationary vehicle.

[0056] In one example, the estimated environmental conditions might include an absolute ambient temperature estimated over a period of standstill. In another example, a change in ambient temperature over time might be measured. In yet another example, ambient humidity might be estimated over time. In a further example, a commanded air / fuel ratio or mass ratio of the measured airflow to the measured fuel flow might be estimated.

[0057] At 412, it can be determined, based on the estimated environmental operating conditions, whether the vehicle is in an enclosed space. An enclosed space might include, for example, an indoor parking structure, while an open space might include, for example, an outdoor parking structure. As shown here with reference to Fig. 5 elaborated, a power engine control unit can be configured to infer, based on input from one or more vehicle location sensors, an on-board vehicle navigation system, a change in ambient temperature over the selected standstill duration, a change in ambient humidity over the selected duration, a change in commanded air / fuel ratio over the selected duration, or a combination thereof, whether the vehicle is in an enclosed space or an open space.

[0058] The control unit can, for example, automatically shut off the engine at idle in response to an increase in ambient temperature exceeding a threshold for a certain period while the vehicle is stationary in an enclosed space. Here, the increase in ambient temperature can indicate that the vehicle is in an enclosed space. In an alternative example, the control unit can automatically shut off the engine at idle in response to the ambient temperature remaining above a threshold for a certain period while the vehicle is stationary in an enclosed space. Here, the higher ambient temperature condition can indicate a reduced need for cabin heating. With no need to operate a vehicle HVAC system, the engine can be shut off while the vehicle is stationary at idle.

[0059] If the vehicle is in an enclosed space, such as an indoor parking lot, then the routine at 412 includes automatically shutting off the engine while idling, for example, after a preselected idling time or essentially immediately. In one embodiment, if the vehicle is in an enclosed space, the engine may be automatically shut off while idling regardless of whether the vehicle is occupied or unoccupied and regardless of the driver's proximity to the vehicle (if unoccupied). In an alternative embodiment, however, if the vehicle is in an enclosed space, the idling time prior to the automatic shutdown of the engine may be based on whether the vehicle is occupied or unoccupied and further on the driver's proximity to the vehicle.The idle time can be shortened, for example, if the distance between the driver and the vehicle increases when the vehicle is in an enclosed space. In yet another example, the idle time before automatic shutdown can be based on the battery's state of charge. For instance, if the battery's state of charge is lower than a threshold, the idle time before shutdown can be extended to allow the battery to reach the threshold state of charge (e.g., 30% SOC), thereby reducing the likelihood of an automatic engine restart immediately after shutdown.

[0060] If the vehicle is not in an enclosed space, then routine 414 includes preventing the automatic engine shutdown at idle based on the fact that the vehicle is located in an open space, such as an outdoor parking lot or open-air parking structure. This prevention may involve delaying the engine shutdown and extending the idle time before automatic shutdown based on an environmental condition, such as the ambient temperature of the location. For example, the routine may include increasing the delay if the ambient temperature falls below a threshold temperature while the vehicle is stationary in an open space.By extending the idle time in response to the ambient temperature being lower than a threshold—that is, in response to cold ambient conditions—the engine can be kept running to operate the vehicle's HVAC system and provide cabin heating. Consequently, a desired level of cabin comfort can be provided for the driver upon returning to the vehicle.

[0061] In another example, the delay might be based on a change in ambient temperature over the time the vehicle is stationary in an open space. For instance, the vehicle might be parked in a location with a high ambient temperature (e.g., in Texas, where the ambient temperature is 105 degrees F), and it might be desirable to keep the engine idling to assist with air conditioning (for example, because the driver has left a pet or passengers in the vehicle). Here, the detected ambient temperature cannot be expected to rise rapidly from a starting point, but delaying shutdown might still be desirable.

[0062] If one now Fig. Section 5, an example routine 500, is shown for deriving the location of a stationary vehicle (e.g., whether the vehicle is located in an enclosed space or an open space) based on ambient operating conditions and / or on the basis of a commanded air / fuel ratio (or mass ratio). In particular, the location can be based on a change in ambient temperature, a change in ambient humidity, and / or a change in the mass of an airflow relative to a fuel flow to an injector (also referred to here as the commanded air / fuel ratio), as estimated over a period of stationary operation. As in Fig. As detailed in section 4, a control unit can be configured to automatically shut off a vehicle engine when the vehicle is idling at a standstill in response to the location (e.g., location of an open space or enclosed space) of the vehicle.

[0063] At 502 (as at 402 of Fig. 4) It can be confirmed that the vehicle is stationary and the engine is running. If not, baseline values ​​of estimated ambient operating conditions (e.g., ambient temperature and humidity) can be deleted. At 504 (as at 406 of Fig. 4) It can be confirmed that no driver input was received for a period of standstill. After confirmation, the location of the vehicle can be inferred based on one or more estimated ambient temperature and / or humidity (as elaborated in 508-514), a commanded air / fuel ratio or mass ratio (as elaborated in 516-520), and a navigation system and one or more location sensors (as elaborated in 522-524).

[0064] A first method for deriving the vehicle's location based on an estimated ambient temperature and humidity is now discussed. In section 508, an ambient temperature and / or ambient humidity is estimated over a period of inactivity. The ambient temperature can be estimated by a temperature sensor connected to the exterior of the vehicle or by a sensor connected to the vehicle's air intake system in conjunction with air outside the vehicle. Similarly, the ambient humidity can be estimated by a humidity sensor connected to the exterior of the vehicle or by a sensor connected to the vehicle's air intake system in conjunction with air outside the vehicle. Alternatively, the ambient air temperature can be derived from other vehicle operating parameters.At 510, it can be determined whether there is an increase in the estimated temperature and / or humidity over time, and whether the increase is greater than a threshold. If so, then routine 512 includes concluding that the location is an enclosed space, in response to the fact that the increase in the estimated ambient temperature and / or humidity is greater than the threshold. If not, then routine 514 includes concluding that the location is an open space, based on the fact that the increase in the estimated ambient temperature and / or humidity is less than the threshold.

[0065] A second method for inferring the vehicle's location based on a change in a commanded air / fuel ratio will now be discussed. In principle, the commanded air / fuel ratio can be estimated by monitoring changes in manifold airflow relative to changes in injector fuel flow in closed-loop operation, while maintaining an exhaust air / fuel ratio (e.g., as estimated by an EGO sensor) at stoichiometry. However, if the oxygen content of the engine intake air is reduced (e.g., due to displacement of ambient oxygen by exhaust), the mass airflow sensor (or the manifold absolute pressure sensor) will not identify the difference in intake air oxygen concentration using this method (e.g., because the hot-wire airflow sensor in the MAF measures the same mass flow regardless of whether the oxygen concentration has changed).The fuel injection is adjusted based on feedback from the exhaust gas sensor due to reduced oxygen levels (e.g., decreased), and the control unit can observe an increase in the ratio of measured airflow to measured fuel flow (due to the reduction in injected fuel, as caused by the feedback from the exhaust gas sensor to maintain exhaust gas stoichiometry) and can consequently identify the closed space. This contrasts with changes caused by alterations (e.g., reductions) in engine friction (where the ambient oxygen concentration remains unchanged), insofar as the measured ratio of airflow (e.g., from the MAF) to injected fuel flow remains relatively unchanged while exhaust gas stoichiometry is maintained.

[0066] At 516, it can be confirmed that purging conditions are not present and that purging fuel vapors from the fuel tank is not possible. During confirmation at 518, manifold airflow and injector fuel flow can be measured and / or estimated over the duration of the standstill. The manifold airflow can be measured using a manifold airflow sensor (such as the MAF sensor 122 from [manufacturer name]). Fig. 3), a manifold pressure sensor (such as the MAP sensor 124 from Fig. 3) or a combination thereof can be measured. The injector fuel flow can, for example, be estimated based on a fuel pulse width.

[0067] At 520, it can be determined whether an increase in the commanded air / fuel ratio persists in closed-loop operation over time, and whether this increase exceeds a threshold value. Specifically, it can be determined whether any change in the measured airflow relative to the measured fuel flow during closed-loop operation exceeds a threshold value (while maintaining the exhaust air / fuel ratio at stoichiometry). In a closed environment, the amount of oxygen available for combustion can progressively decrease, causing the air / fuel ratio to appear richer. To compensate for the lower proportion of oxygen in the air mass, the manifold airflow can be increased by an engine control unit.In response to an increase in the commanded air / fuel ratio (or mass ratio) being greater than a threshold change, a closed space at 512 can consequently be inferred. Conversely, in response to an increase in the commanded air / fuel ratio (or mass ratio) being less than the threshold change, an open space at 514 can be inferred. By measuring both the manifold airflow and the fuel flow, and determining the vehicle's location based on each of the measured parameters, a change in airflow resulting from an increase in friction (e.g., during a cold start or due to air conditioning compressor operation) can be better distinguished from a change in airflow resulting from a decrease in the ambient oxygen concentration.Consequently, a false positive determination of an enclosed space (due only to a change in airflow) can be reduced.

[0068] In this way, an engine control unit can automatically shut down an engine in response to a comparison of the measured airflow to the measured fuel flow during idling operation, including shutting down the engine if the fuel flow decreases for a given measured airflow (e.g., decreases below a threshold) while maintaining stoichiometry in the engine exhaust.

[0069] A third method for deriving the vehicle's location based on input from a navigation system and / or location sensors is now discussed. In 522, input is received from one or more of the vehicle's location sensors, the vehicle's onboard navigation system, and a mobile navigation system coupled to a vehicle engine control module. The mobile navigation system may, for example, be configured on a mobile device (such as a mobile phone or portable GPS) carried by the driver and communicatively coupled or synchronized with a vehicle engine control module. In yet another example, input may be received in the form of a broadcast signal, such as a transmitted radio signal. The broadcast signal may be transmitted through the location where the vehicle is situated (e.g.,(via a transmitter in the indoor / outdoor parking garage) and can specify, in particular, the location and whether the location is enclosed or open. With 524, it can be deduced, based on the received input, whether the vehicle is in an enclosed or open space. In one example, the navigation system can determine the vehicle's location using dead reckoning. The navigation system can, for instance, position the vehicle within a parking structure using dead reckoning and can further utilize additional map information to determine whether the parking structure is in an open or enclosed space. For example, if the location is an outdoor parking lot or open-air parking structure, it can be determined that the vehicle is in an open space. In another example, if the location is an indoor parking lot, it can be determined that the vehicle is in an enclosed space.

[0070] In another embodiment, where the vehicle is unoccupied and the driver possesses a passive key for operating the vehicle, the passive key being communicatively coupled to the vehicle via a sensor, the vehicle's location can be deduced based on the driver's proximity to the vehicle, as determined by the position of the passive key. In either case, if the location is an enclosed space, a power engine control unit can automatically shut down the vehicle's engine when idling, while if the location is an open space, the control unit can extend the idling time before automatically shutting down the vehicle's engine when idling.

[0071] During a first power engine idling condition, a control unit might be configured to shut down the power engine in response to the vehicle being located in an enclosed space. In this example, the vehicle might be parked in an indoor parking space during the first condition. In another example, during a second power engine idling condition, the control unit might be configured to delay the power engine shutdown in response to the vehicle being located in an open space, with the delay being set based on the ambient temperature of the open space. In this example, the vehicle might be parked in an outdoor parking space during the second condition. The setting might include increasing the delay if the ambient temperature of the open space falls below a threshold temperature.The ambient temperature can be estimated over a period of standstill by a temperature sensor that is communicatively coupled to the ambient air outside the vehicle. During each of the first and second engine idling conditions, the vehicle itself may be parked and unoccupied, for example, while the driver may be beyond a threshold distance from the vehicle. Whether the vehicle is located in an enclosed space or an open space can be determined based on input from one or more of the following vehicle sensors: a navigation system (e.g., on-board or communicatively coupled to the vehicle), a location sensor, a radio signal, a temperature sensor, a humidity sensor, an air / fuel ratio sensor, and other vehicle sensors.

[0072] In this way, a vehicle can be controlled by its engine when stationary, with the engine idling. For example, if the driver has left the vehicle with the engine inadvertently running, the engine can be switched off while idling. By automatically switching off the engine and reducing the idling time when the vehicle is in an enclosed space, fuel waste and exhaust emissions can be reduced, as well as the deterioration of the enclosed space's air quality. However, if the driver has intentionally left the engine running, the idling time can be extended to provide the desired level of cabin comfort, particularly during cold ambient conditions. In this way, the driving experience can be improved.

[0073] It should be noted that the example control and estimation routines contained herein can be used with various power machine and / or vehicle system configurations. The specific routines described here can represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multitasking, multithreading, and the like. In principle, various actions, operations, or functions shown in the sequence can be performed in parallel or, in some cases, omitted. Likewise, the order of processing is not necessarily required to achieve the features and benefits of the example implementations described here, but is included for ease of explanation and description.One or more of the depicted actions or functions can be performed repeatedly, depending on the specific strategy used. Furthermore, the described actions can graphically represent code to be programmed into the computer-readable storage medium in the powertrain control system.

[0074] It is evident that the configurations and routines disclosed herein are essentially exemplary and that these specific embodiments should not be considered limiting, as numerous variations are possible. For example, the above technology can be applied to V-6, I-4, I-6, V-12, 4-boxer, and other types of power engines. The subject matter of this disclosure includes all new and non-obvious combinations and sub-combinations of the various systems and configurations and other features, functions, and / or properties disclosed herein.

[0075] The following claims specifically indicate certain combinations and subcombinations that are considered novel and not obvious. These claims may refer to "one" element, "a first" element, or the equivalent thereof. Such claims should be understood as the comprehensive integration of one or more such elements, neither requiring nor excluding two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, and / or properties may be claimed by amending the present claims or by filing new claims in this or a related application. Such claims, whether broader, narrower, the same, or different in scope compared to the original claims, shall also be considered to be included in the subject matter of the present disclosure.

Claims

[1] Method for steering a stationary vehicle comprising: Automatic prevention of the shutdown of a vehicle engine at idle based on an ambient temperature and a determination of whether the vehicle is located in an enclosed space or an open space, wherein the determination is based on an input from one or more of a navigation system coupled to the vehicle, a location sensor, a radio signal and a manifold airflow sensor of the vehicle. [2] Method according to claim 1, wherein the ambient temperature of the location is estimated over a period of standstill. [3] Method according to claim 2, wherein the prevention is further based on one or more ambient humidity and a commanded air / fuel ratio, and wherein the prevention comprises delaying the shutdown of the engine at idle in response to one or more of the following: that the ambient temperature is lower than a threshold temperature, the ambient humidity is higher than a threshold humidity, and the commanded air / fuel ratio is higher than a threshold air / fuel ratio over the period of time, and the vehicle is stationary in an open space. [4] Method according to claim 2, wherein preventing the engine from being switched off at idle in response to one or more of the following: that a change in ambient temperature, a change in ambient humidity and a change in the commanded air / fuel ratio is greater than a threshold level over time and the vehicle is stationary in an open space. [5] Method according to claim 3, wherein the delay of switching off comprises increasing an amount of delay when the ambient temperature falls below the threshold temperature while the vehicle is stationary in an open space. [6] The method of claim 5, further comprising the automatic shutdown of the engine at idle in response to the fact that the ambient temperature is higher than the threshold temperature for a certain period of time while the vehicle is stationary in an open space. [7] Method according to claim 6, further comprising automatically switching off the engine at idle in response to an increase in the ambient temperature exceeding a threshold value for a period of time while the vehicle is stationary in an enclosed space. [8] Method according to claim 7, wherein the open space comprises an outdoor parking area and wherein the enclosed space comprises an indoor parking area. [9] Method according to claim 1, wherein the location is based on an input from one or more of a location sensor of the vehicle, an on-board vehicle navigation system, a radio signal and a mobile navigation system that is communicatively coupled with a power engine control module of the vehicle. [10] Method according to claim 1, wherein the vehicle is unoccupied, wherein a vehicle driver has a passive key for operating the vehicle, wherein the passive key is communicatively coupled to the vehicle by means of a sensor, and wherein the location of the vehicle is based on the proximity of the driver to the vehicle, the proximity being determined by a position of the passive key. [11] Method for steering a vehicle with a power engine, wherein the vehicle is stationary, comprising: During an initial engine idling condition, the engine shuts down in response to the vehicle being located in an enclosed space; and During a second engine idling condition, delaying the engine shutdown in response to the vehicle being located in an open space, with the delay being set based on the ambient temperature of the open space. where, whether the vehicle is located in an enclosed space or in an open space, the input from one or more of a navigation system coupled to the vehicle, a location sensor, a radio signal and based on a manifold airflow sensor of the vehicle, and / or wherein during each of the first and second engine idling conditions the vehicle is parked and optionally unoccupied. [12] Method according to claim 11, wherein the retardation is dependent on whether a commanded air / fuel ratio is higher than a threshold value. [13] Method according to claim 11, wherein the setting comprises increasing the delay when the ambient temperature of the open space falls below a threshold temperature. [14] Method according to claim 11, wherein during the first condition the vehicle is parked in an indoor parking space, and wherein during the second condition the vehicle is parked in an outdoor parking space. [15] Method for steering a stationary vehicle, comprising: Automatic prevention of the shutdown of a vehicle engine at idle based on an ambient temperature and a determination of whether the vehicle is located in an enclosed space or an open space, wherein the determination is based on an input from a temperature sensor and / or a humidity sensor, whereby it is inferred that the vehicle is located in an enclosed space if a change in ambient temperature and / or a change in ambient humidity over the period of standstill is greater than a threshold value. [16] Vehicle system comprising the following: a power machine; a driver ignition interface for initiating and / or terminating the operation of the engine; a passive key that is communicatively coupled to the driver ignition interface and is configured to initiate and / or terminate the operation of the power unit based on driver input; a temperature sensor located on an external surface of the vehicle and configured to estimate an ambient temperature; a navigation system with one or more location sensors configured to estimate the vehicle's location; and a power engine control unit with computer-readable commands for: When the vehicle is stationary, with the engine idling and the proximity of the driver exceeding a threshold, extending the idle time before automatically shutting off the engine in idle mode based on the ambient temperature estimated over the duration of the standstill. [17] System according to claim 16, wherein the extension comprises extending the idle time when the estimated ambient temperature falls below a threshold temperature. [18] System according to claim 16, wherein the control unit includes further commands to avoid extending the idle time when the vehicle is stationary, the engine is idling, and the proximity of the driver is less than the threshold. [19] System according to claim 16, wherein the vehicle is not occupied by the driver during the period of standstill.

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