Method for controlling the stopping and starting of an engine

Abstract

A method for controlling an internal combustion engine of a vehicle, comprising: Receiving at least one input indicative of a current external environment in the vicinity of the vehicle; Determining a rate of approach between the vehicle and a detected object; Determining, in dependence on the at least one input, whether a hazard exists, wherein determining whether a hazard exists comprises determining a rate of approach between the vehicle and a detected object; Determining a current propulsion demand of the vehicle; if it is determined that the current propulsion demand is low, either instructing the internal combustion engine to switch to a switched-off state if it is determined that no danger exists, or not instructing the internal combustion engine to switch to the off state when it is determined that a hazard exists; and if it is determined that the current drive demand is high, instructing the engine to switch to an on-state when the engine is in the off-state, wherein determining whether a hazard exists includes determining the type of intersection approached by the vehicle, determining whether the intersection is an intersection, a roundabout, or a junction.

Description

TECHNICAL FIELDThe present disclosure relates to a method of controlling an internal combustion engine of a vehicle. More particularly, but not exclusively, it relates to a method for shutting down and starting an internal combustion engine of a vehicle.Aspects of the invention relate to a method, a control device and a computer-readable medium.PRIOR ARTIt would be desirable to shut down an internal combustion engine of a vehicle while the vehicle is moving. This energy saving measure reduces fuel consumption and emissions.In this context, DE 10 2011 009 001 A1 relates to a method for automatically stopping an internal combustion engine of a motor vehicle.DE 10 2011 007 716 B4 relates to a method for operating an automatic start / stop system in a motor vehicle with an internal combustion engine and an automatic clutch, wherein the automatic start / stop system automatically opens the clutch as a function of propulsion requirements, wherein the automatic opening of the clutch is prevented (3) in specific driving situations, wherein the driving situations in which the automatic opening of the clutch is prevented comprise automatically recognized hazardous situations (1, 2), characterized in that a driving situation is automatically recognized (1, 2) as a hazardous situation at least when the driver takes an action in order to inform other road users of a hazardous situation recognized by him.DE 10 2014 014 293 B3 relates to a method for operating a motor vehicle having a start-stop system for an internal combustion engine, having a device for detecting a vehicle environment, wherein the start-stop system stops the internal combustion engine as a function of at least one signal relating to the driving dynamics of the motor vehicle when a limit value of a speed of the motor vehicle is undershot.The present invention aims to eliminate the disadvantages associated with the prior art.SUMMARY OF THE INVENTIONAspects and embodiments of the invention provide a method, a controller, a vehicle, and a computer readable storage medium according to the appended claims.According to an aspect of the present invention, there is provided a method of controlling an engine of a vehicle, comprising: receiving at least one input indicative of a current external environment in the vicinity of the vehicle; determining, in dependence on the at least one input, whether there is a danger; determining a current drive request of the vehicle; if it is determined that the current drive request is low, either instructing the engine to switch to a turned-off state if it is determined that there is no danger or not instructing the engine to switch to the turned-off state if it is determined that there is a danger; and when it is determined that the current drive request is high, instructing the engine to switch to an on state when the engine is in the off state.This provides the advantage of ensuring that the engine is in its on state before an expected rapid increase in the drive request by a driver of the vehicle in response to a suspect risk in the external environment. An example of a putative hazard is an obstacle on the road that can be overcome when the driver decides to do so. Determining that a risk is present may include identifying the presumed risk and identifying a propulsion request.In some examples, if it is determined that the current propulsion request is low and the engine is in an off state, the method comprises either instructing the engine to switch to the on state if it is determined that there is a risk or not instructing the engine to switch to the on state if it is determined that there is no risk.This provides the advantage of ensuring that the engine switches to its on state prior to an expected rapid increase in the drive demand by the driver of the vehicle in response to the suspect risk.Determining that there is no risk may include determining an expected low or no increase in a future propulsion request, and determining that there is a risk may include determining an expected future propulsion request or an increase in the propulsion request. This provides the advantage of saving energy when the driver is expected not to increase the drive demand.The at least one input may include inputs from a plurality of different sensors. The at least one input may include: image data; location data; pulse reflection data; and / or information received from another vehicle and / or infrastructure management system over a wireless network. This provides the advantage that hazards are less likely to be overseeed.Determining whether there is a risk may include detecting, in the current external environment in the vicinity of the vehicle, an environment that is likely to require slowing of the vehicle. This provides the advantage that only environments that may lead to damage when the driver is not braking and / or stops the vehicle, such as collision damage to the vehicle, and / or may cause the injuries to its occupant, may be determined to represent hazards.Determining whether there is a risk may include determining an approach rate between the vehicle and a detected object. An approach rate is expressed in terms of speed units. In some examples, the detected object is an object in the field of view of the driver. Determining that there is a risk may include determining that the vehicle and the detected object are approaching each other. This provides the advantage that only environments that require the driver to decide whether to slow or not slow in response to the object can be determined to represent hazards.Determining whether there is a risk may include determining a current decrease in the approach rate. Determining that there is a risk may comprise determining that there is no current decrease in the approach rate or that the current decrease in the approach rate does not exceed a threshold. This provides the advantage that only the kinds of environments in which the driver has not decided to be finally decelerating the vehicle can be determined to represent hazards.Determining whether there is a risk may include determining whether the vehicle is controlled to decrease the approach rate. Determining that there is a risk may include determining that the vehicle is not being controlled to reduce the approach rate. This provides the advantage that only the kinds of environments in which the driver has not decided to be finally decelerating the vehicle can be determined to represent hazards.The risk may include: an active risk occurring due to actions taken by the driver of the vehicle and / or other road users; and / or a passive risk occurring due to road layout, road infrastructure, and / or topography. This provides the advantage that a wide variety of putative hazards can be determined as hazards.The active risk may include a road user moving more slowly in front of the vehicle than the vehicle, or he slowing down. This provides the advantage that the method assists in passing.The passive hazard may include: a terrain feature that may cause damage to at least the vehicle; a road layout feature that provides the pass to other road users; and / or a road infrastructure feature that provides the pass to other users. This provides the advantage that potential future active hazards may be anticipated.The terrain may comprise a flooded driving surface. This provides the advantage that the potential future active risk of the vehicle getting stuck in the water can be anticipated.The road layout feature may include an intersection. This provides the advantage that the method supports an intersection maneuver.Determining whether there is a risk may include recognizing a risk sign using image processing.In some examples, the engine is decoupled from at least one vehicle wheel in the configured state.According to another aspect of the present invention, there is provided a method of controlling a driving system of a vehicle, comprising: causing the driving system to be switched to an off state; or executing the switching depending on a current low driving request only when it is determined that there is no danger by processing at least one signal indicative of a current external environment in the vicinity of the vehicle.This provides the advantage that the method can be applied to any propulsion means capable of accelerating the vehicle and wasting energy while not being used to accelerate the vehicle, without being limited to an internal combustion engine.According to a further aspect of the invention, a control device is provided, comprising means for executing one or more of the described methods. In some examples, the means for executing one or more of the described methods is at least one processor; and at least one memory containing computer program code; wherein the at least one memory and the computer program code are configured to cause, with the at least one processor, the operation of one or more of the described methods.According to a further aspect of the invention, a vehicle is provided which comprises the control device.According to another aspect of the invention, there is provided a computer readable storage medium having computer program instructions stored thereon which, when executed by a processor, cause one or more of the described methods to be carried out.According to another aspect of the present invention, there is provided a method of controlling an engine of a vehicle, comprising: receiving at least one input indicative of a current external environment in the vicinity of the vehicle; when at least one condition dependent on the at least one input is not satisfied, switching the engine to an off state depending on a low drive request; and when the at least one condition associated with the at least one input is satisfied, not switching the engine to an off state depending on a currently low drive request. The at least one condition may be a condition that is met when the at least one risk is determined to be present by processing the at least one input as described herein; otherwise, the condition is deemed not met.According to some but not all examples, there is provided a method of controlling an engine of a vehicle, comprising: receiving at least one input indicative of a current external environment in the vicinity of the vehicle, and determining, in dependence on the at least one input, whether there is a risk; if it is determined that there is no risk, enabling the engine to switch to a switched-off state in dependence on a low drive request; and if it is determined that there is a risk, not enabling the engine to switch to a switched-off state in dependence on a current low drive request.Within the scope of this application, it is expressly intended that the various aspects, embodiments, examples and alternatives presented in the preceding paragraphs, in the claims and / or in the following description and drawings, and in particular their individual features, may be taken into account independently of each other or in any combination. This means that all embodiments and / or features of any embodiment can be combined in any manner and / or any combination, provided that these features are not incompatible. Applicant reserves the right to alter any originally filed claim or to submit any new claim accordingly, including the right to alter any originally filed claim to depend on and / or integrate any feature of any other claim, although in this manner it has not been previously claimed.BRIEF DESCRIPTION OF THE DRAWINGSOne or more embodiments of the invention will now be described, by way of example only, with reference to the accompanying drawings, in which: FIG. 1 shows an example vehicle 1; FIG. 2A shows an exemplary control device 4; FIG. 2B shows an exemplary computer readable storage medium 9; FIG. 3A illustrates an example method 300; FIG. 3B is a state diagram; FIG. 4 shows a further exemplary method 400; FIG. 5 shows a further exemplary method 500; and FIG. 6 shows a further exemplary method 600.DETAILED DESCRIPTIONThe figures show a method 300, 400, 500, 600 for controlling an internal combustion engine 3 of a vehicle 1, comprising: receiving at least one input 301, 401, 501, 601 indicative of a current external environment in the vicinity of the vehicle 1; determining 305, 460, 650, depending on the at least one input, whether there is a danger; determining a current propulsion request 303 of the vehicle 1; if it is determined that the current propulsion request 303 is low, either instructing the internal combustion engine 3 to switch to a switched-off state 307 if it is determined that there is no danger or not instructing the internal combustion engine 3 to switch to the switched-off state if it is determined that there is a danger; and when it is determined that the current drive request 303 is high, instruct that the engine 3 is switched to an on state when the engine 3 is in the off state.FIG. 1 shows an example of a suitable vehicle 1 in which the described methods could be carried out. The vehicle 1 may be a passenger car. The vehicle 1 includes a drive system 2 for driving the vehicle 1, which includes an internal combustion engine 3.Other drive systems 2 are conceivable, such as hybrid drive systems including the internal combustion engine 3 and other drive means (not shown).The vehicle 1 from FIG. 1 further comprises a control unit 4, operatively connected to the drive system 2 for carrying out the described methods.FIG. 2A illustrates an example controller 4. In the example of FIG. 2A, the control device 4 comprises at least one processor 5; and at least one memory 6 which contains computer program code 8; the at least one memory 6 and the computer program code 8 being configured to cause the operation of the described methods with the at least one processor 5.As illustrated in FIG. 2B, the described methods may be implemented using instructions that enable hardware functionality, for example, by using executable instructions 8 of a computer program 7 in a general purpose or special purpose processor 5 stored on a computer readable storage medium 9 (disk, memory, etc.) to be executed by such a processor 5.According to some, but not necessarily all, examples, the controller 4 is operable to command the engine 3 to switch between an on state ("active" or "started" engine state) and an off state ("inactive" or "stopped" engine state).The engine 3 may provide torque to propel the vehicle 1 in the turned-on state to cause the vehicle 1 to accelerate. In the switched-on state, the internal combustion engine 3 is coupled to at least one vehicle wheel 10 via mechanical components (not shown). In the on state, fuel is supplied to the engine 3 to be converted into mechanical energy to drive the vehicle 1.The engine 3 may not provide torque for propelling the vehicle 1 in the off state. In some examples, when configured, engine 3 is decoupled from the at least one vehicle wheel 10, thereby allowing a rotatable crankshaft (not shown) in engine 3 to stop rotating while vehicle wheel 10 continues to rotate. In some examples, no fuel is provided to engine 3 in the off state.According to some, but not necessarily all examples, the controller 4 is operable to command the engine 3 to switch to the off state depending on a current low propulsion request, for example to conserve fuel. The controller 4 is operable to instruct the engine 3 to switch back to the on state depending on a current high drive request when the engine 3 is in the off state.The engine 3 may switch to the off state while the vehicle 1 is moving with respect to its environment in response to a current low drive request, or at any other time between the time the vehicle 1 is switched to an ignition-on ("key-on") vehicle state by its driver and the time it is switched to an ignition-off ("key-off") vehicle state by its driver.The term drive request refers to an amount of drive energy, such as positive torque, for driving the vehicle 1 requested by the drive system 2 in response to a driver torque request, such as accelerator pedal input, while the vehicle 1 is in the key-on state.The drive request is determined by the controller 4 in dependence on a measurement by any suitable sensor means, such as by using an accelerator pedal position sensor.The drive requirement is a variable with multiple levels. Numerous levels may include more than ten levels; in other examples, over one hundred levels or over one thousand levels of propulsion demand may be present.The term low propulsion demand refers to, for example, a propulsion demand condition that is met when there is no propulsion demand or when the propulsion demand is below a propulsion demand threshold. In some examples, the propulsion demand condition is met while none of the vehicle wheels 10 are receiving propulsion torque from the propulsion system 2.The term high propulsion demand refers to, for example, a propulsion demand condition that is met when a propulsion demand is present or when the propulsion demand is above a threshold, such as the propulsion demand threshold. In some examples, the high propulsion demand condition is met while at least one vehicle wheel 10 receives propulsion torque from the propulsion system 2.The term current propulsion request refers to a real-time measurement of the propulsion request received from controller 4. The controller 4 may react in real time to instruct the engine 3 to switch to the off state after a short delay after the current drive request becomes low. The internal combustion engine 3 may switch back to the on state after a similarly short or shorter delay after the current drive request is no longer low. In either case, the delay may be a shorter time than: 5 seconds; 2 seconds; or 0.5 seconds. The delay time is associated with hardware functionality and in some cases serves to trigger a preprogrammed delay when switching to the off state.FIGS. 3 to 6 show examples of methods for further improving the functionality of the control unit 4.FIG. 3A shows an example of a method 300. The method 300 includes, at block 301, receiving at least one input indicative of a current external environment in the vicinity of the vehicle 1.The input includes input data that can be received directly from any suitable sensor on the vehicle 1, arranged to sense the current environment outside the vehicle 1, or indirectly via one or more intervening elements.The received input indicates the current environment because there is only a minimum delay between reading data by the sensor and receiving the input comprising the data, such as less than one second.In some examples, the input data includes local real-time context data indicative of a local real-time context around the vehicle 1 and outside the vehicle 1. This local real-time context data allows information about objects in the monitored field of view of the sensor to be determined by processing the data and objects to be detected. Object detection may be performed by any suitable technique, such as image processing.The real-time local context data indicates real-time context, thus driver-viewed objects that are transient features in the environment, such as other road users, including pedestrians and other vehicles, or transient road excavation, such as worksite objects, may be determined.Examples of suitable inputs of local real-time context data received at block 301 include: image data; audio data; transmitted impulse reflection data; and / or information received from another vehicle or infrastructure management system over a wireless network. Image data may be received from a visual camera; and / or an infrared camera on vehicle 1. pulse reflection data may be received from a pulse reflection sensor, such as a radar or light detection and ranging (LIDAR) sensor on vehicle 1. audio data may be received from a microphone on vehicle 1. audio data received from another vehicle or an infrastructure management system may be received by a wireless receiver on vehicle 1.Information from another vehicle may include information about the speed, location, and direction of the other vehicle, or any other suitable information about the local real-time context around the vehicle 1. Information from an infrastructure management system may include congestion information, information about the state of a road infrastructure object, such as a traffic light, or any other suitable information about the local real-time context around the vehicle 1.In some examples, the sensor provides a field of view and the sensor is oriented such that the heading of the vehicle 1 is within the boundaries of the field of view of the input data. The sensor may include a forward facing camera oriented in the forward travel direction of the vehicle 1.In some examples, the input data includes location-based data. Location-based data does not necessarily allow all aspects of the local real-time context to be determined around the vehicle 1. For example, location-based data does not allow objects with transient features to be determined in the environment to be seen by the driver, such as other road users. Location-based data may include map data and may indicate the current location of the vehicle 1 on a virtual map.Location-based data may allow changes in road layout to be detected by processing input data. Detecting a change in road layout may include determining that the vehicle 1 is approaching an intersection where the vehicle 1 does not have a heading. An intersection type is recognized as to whether it is a conventional intersection, a circular traffic or a merging point. In some examples, it is detected whether the vehicle 1 has traveled in front of the intersection.In some examples, only the next change in road layout or only the few next changes in road layout along a particular route of vehicle 1 are detected without location-based data indicative of an entire remaining route or a substantial portion of the route. Thus, the location-based data includes only road layout changes in the vicinity of the current location of the vehicle 1.Location-based data may be received from a Global Navigation Satellite System (GNSS) sensor or may be determined with data from a GNSS sensor.The method 300 includes, at block 303, determining a current drive request depending on information from a suitable sensor, such as a driver-to-be-actuated sensor, such as an accelerator pedal position sensor.The method 300 comprises, in block 305, determining, depending on the input(s) received, whether there is a risk.In some examples, it is determined that there is a risk when at least two risk analysis conditions are met at the at least one input. To meet the first condition (identify a putative hazard), processing at least one input indicates a hazard in the current external environment in the vicinity of the vehicle 1 where there is a probability greater than a threshold (non-zero) that the vehicle 1 is damaged and / or its occupants are injured. The hazardous environment could include one or more detected objects, such as an approaching intersection or a slower moving vehicle.In some examples, the threshold is whether a particular object, such as a vehicle other than vehicle 1 or an intersection, is detected. In some examples, the detected object must also be at a threshold distance from the vehicle 1. In some examples, a quantitative decision is made as to whether an environment is a hazardous environment, such as by calculating a value that quantitates the likelihood of damage by the environment and comparing the value to a threshold.To meet the second condition (identify a propulsion request), processing the at least one input and, in some examples, the driver behavior data indicates that the driver is expected to increase the future propulsion request in response to the hazardous environment. In some examples, this is achieved by determining that the likelihood of damage may be reduced by the driver increasing the propulsion request. Further, it can be determined that the likelihood of damage can only be prevented by the driver braking unusually sharply, such as for that specific driver.An example of a risk that satisfies the first and second conditions will be described. First, processing real-time context data indicates a slow-moving vehicle in front of the vehicle 1 moving in the same direction as the vehicle 1. the first condition for identifying a presumed risk is fulfilled, for example, because the slow-moving vehicle has been detected or because the other vehicle is within a certain distance from the vehicle 1.Thereafter, processing the real-time local context data and, in some cases, the speed of the vehicle 1 as well as an accelerator pedal position of the vehicle 1 indicate the approach rate of the vehicle 1 to the slower-driving vehicle, and further, in some cases, indicate whether the approach rate changes. Processing demonstrates that the driver would need to brake significantly more sharply than usual to prevent it from colliding with the slower driving vehicle, such as braking more sharply than a vehicle-specific or driver-specific threshold deceleration. This satisfies the second condition for identifying a propulsion request, as the driver may be inferred to intend to pass the slower vehicle and will likely increase the propulsion request or intend to do so.In some examples, a particular risk may be determined as an active risk or a passive risk.Active hazards may occur due to detected measures, such as maneuvers performed by the rider of the vehicle 1 and / or by other road users, such as pedestrians, animals, cyclists, and riders of other vehicles. Active hazards require the vehicle 1 to accelerate or brake to prevent damage. The above example of the slower-driving vehicle is an example of an active danger.Passive hazards do not arise from measures by the vehicle 1 and other road users. Passive hazards include environments where the likelihood of active danger and / or damage is high, but not safe. Examples of passive hazards include: terrain features that may cause damage to at least the vehicle 1; road layout features that provide the priority to other road users; and road infrastructure features that provide the priority to other users. In some examples, passive hazards are stationary objects or features.In some examples, the threshold for checking the first condition may be set such that suspect hazards having a low probability of damage being generated may be ignored by the hazard analysis. Some environments are environments in which hazards are unlikely to occur because the likelihood of damage is below the threshold even if there is a likelihood of an increased drive request. Examples of these environments include increasing slopes; straightening of the vehicle 1 when going out of a curve or turning; and slower vehicles traveling in lanes other than the vehicle 1.If it is determined in block 305 that there is a risk, then it would be desirable to keep the engine 3 on to allow the engine 3 to quickly respond to an expected future increase in propulsion demand.If it is determined in block 305 that there is no risk, the method 300 continues to block 307, in which the method 300 instructs the engine 3 to switch to the off state. If the engine 3 is already in the OFF state, the engine 3 remains in the OFF state. In this case, the engine 3 may switch to the off state when the current drive request is low.However, if it is determined in block 305 that there is a risk, the method 300 does not proceed to block 307. When the engine 3 is already in the OFF state, it switches to the ON state. In this case, the engine 3 cannot switch to the OFF state or remain in the OFF state when the current drive request is low.In some examples, the method 300 is repeated at a later time to again determine whether there is a risk using updated data from the at least one input and / or an updated current propulsion request at block 305.The interaction between the methods described herein and the state of the internal combustion engine 3 is illustrated in the state diagram in FIG. 3B. The engine 3 may be in one of two states: the on state 311 and the off state 313. As mentioned above, the state of the internal combustion engine 3 can be controlled by a control unit 4.While the engine 3 is in the on state 311, if it is determined that the current drive request 303 is low ("LPD") and it is determined that there is a risk ("H"), the engine 3 remains 315 in the on state 311.The engine 3 transitions 317 from the on state 311 to the off state 313 when it is determined that the current propulsion request 303 is low ("LPD") and it is determined that there is no risk ("NH").The engine 3 transitions 319 from the off state 313 to the on state 311 when it is determined that the current propulsion request 303 is high ("HPD"). In some examples, this transition 319 occurs regardless of whether a risk is determined to be present.The state diagram of FIG. 3B shows that the engine 3 is operating in the on state 311 and does not transition to the off state 313 while there is a risk (H) and / or while the propulsion request is high (HPD).The state diagram of FIG. 3B shows that the engine 3 is operating in the off state 313 and does not transition to the on state 311, while there is no risk (NH) and the drive request is low (LPD).FIG. 4 illustrates an example of a method 400 related to a stop scenario. In some examples, block 401 and / or 402 performs the function of block 301; block 410, 420, 430, 440, 450, and / or 460 performs the function of block 305; and block 473 performs the function of block 307.The method 400 includes, at block 401, receiving an input indicative of a current external environment in the vicinity of the vehicle 1. In this example, the input includes local real-time context data including image data from one or more cameras and / or data from radar sensors and / or LIDAR sensors on vehicle 1. To improve accuracy, inputs from various sensors may be combined, compared, and / or evaluated.The method 400 includes, at block 402, receiving additional input indicative of a current external environment proximate the vehicle 1. In this example, the additional inputs are location-based data including global positioning system (GPS) map data that includes route information related to road layout changes and / or intersection type.The method 400 continues with determining, depending on the input(s) received, whether there is a risk beginning at block 410.In some examples, a risk defining a reason for the vehicle 1 stopping (coming to a stop) is defined in block 410. The hazardous environment satisfies at least the first condition for determining a hazard, as described with respect to block 305.The object / detected objects recognized as forming the danger is linked to a passive danger. The object includes a road layout feature that gives other road users the priority, such as an intersection, for example, a junction, a traditional intersection, or a circular traffic. The object may include a road infrastructure feature that gives other road users the priority, such as a static object, such as a stop sign, or a dynamic object, such as a traffic light changing to a color that indicates that the vehicle 1 does not have a priority. In some examples, this color is a red color. Typically, the driver may stop in front of the road layout feature or the road infrastructure feature, but in some cases the driver recognizes an opportunity to cross an intersection without stopping. This may require accelerating the vehicle 1.In some examples, the object is associated with an active risk. The object may comprise a slowing road user ahead of the path of the vehicle 1, slowing down to standstill in a queue of vehicles. Typically, the driver may be ready to stop behind the road user, but in some cases the driver will recognize an opportunity to change to another lane of traffic traveling. This may require accelerating the vehicle 1.In some examples, the object is a danger sign, such as a road marking on the road surface, or a sign representing a symbolic representation of a danger. The symbolic representation may include a symbol or text corresponding to an entry in an object recognition database. In some examples, a symbol refers to images on a sign and / or the shape of the sign itself.In the example of FIG. 4, method 400 proceeds to blocks 420- 460. In some examples, blocks 420- 460 each define steps in determining whether the second condition for determining a risk as described with respect to block 305 is satisfied.Determining whether there is a risk comprises, in block 420, determining an approach rate between the vehicle 1 and a detected object, such as an intersection or road user in front of and in its path of the vehicle 1. The approach rate is expressed in terms of velocity units.In some, but not necessarily all examples, the speed of the other road user is known to determine the approach rate. Speed could be known from sensing and / or through communication between networked autonomous vehicles.The determination, at block 420, uses the vehicle speed information 411 from a suitable sensor, such as a vehicle wheel speed sensor in an anti-lock brake system; and distance information that determines a distance to the detected object, for example, from the image processing.In some, but not necessarily all examples, determining that there is a risk comprises determining, at block 420, that the vehicle 1 and the detected object are approaching each other, i.e., corresponding to a positive approach rate. For example, the vehicle 1 approaches the detected object such that the vehicle 1 and the object are on a collision course. When the vehicle 1 and the detected object do not approach each other, it is determined that there is no danger.In some examples, block 420 includes determining a distance to the detected object as well as an approach rate.In the example of FIG. 4, the method 400 continues to block 430. Determining whether there is a risk comprises, in block 430, calculating a threshold change in the approach rate, such as deceleration of the vehicle 1 to stop the vehicle 1.In some examples, the calculation determines the threshold, for example, by retrieving a threshold from a memory 6. the threshold may be any suitable value that is below the highest deceleration capability of the vehicle 1. In some examples, the threshold is in the range 0 g<threshold≤1 g. In some examples, the threshold is a soft braking threshold in the range 0.1 g<threshold≤0.4 g. The threshold may be vehicle model specific or general, but is not necessarily driver specific. In some examples, the value of the threshold may be modified by the driver. In some examples, the threshold is dependent on the slope of the road measured by, for example, an inclinometer.In some examples, the threshold is calculated as a deceleration that is not greater than an average required deceleration when the vehicle 1 is to stop before the vehicle 1 reaches or collides with a detected object.In the example of FIG. 4, the method 400 continues to block 440. Determining whether there is a risk comprises determining whether a current change in the approach rate, determined, for example, at block 432 using vehicle speed information 411, is a deceleration that exceeds the threshold change in the approach rate calculated at block 430.If block 440 determines that a current decrease in the approach rate exceeds the calculated threshold change in the approach rate, such as the threshold deceleration, then the method 400 proceeds to block 473, thereby allowing or further allowing the engine 3 to be switched to the off state ("inactive state") depending on a current low drive request. This is because it is inferred that the driver is braking or coasting to decelerate the vehicle 1 to stop with normal deceleration behavior; thus, there is no reason to expect a future rapid increase in the drive request to prevent collision with the object.If there is no decrease in the approach rate, or if the current decrease in the approach rate does not exceed the calculated threshold, then it is inferred that the driver is maintaining or accelerating the vehicle speed and thus he is not intended to bring the vehicle 1 to a standstill. The method 400 continues to block 450.In a variation of method 400, method 400 proceeds from block 420 directly to block 450 without executing block 430 or 440. In an alternative variation, the method 400 skips block 450 and executes blocks 430 and 440.Determining whether there is a risk includes determining whether the current decrease in the approach rate, determined, for example, at block 432 using vehicle speed information 411, exceeds a driver-specific threshold deceleration at block 450. Thus, block 450 determines whether the respective driver is likely to apply deceleration above the threshold to stop the vehicle 1.In some examples, the driver-specific threshold is calculated in blocks 441 and 442 by determining who the vehicle 1 is driving, for example, by processing data captured by a sensor or by a driver-specific device carried by the driver and received by the processor 5, and comparing the data with driver information stored in a memory 6 of the vehicle 1.In this example, the driver-specific threshold deceleration is calculated by determining the historical average deceleration of the driver when braking the vehicle 1 to a standstill at blocks 441 and 442. The historical data may be stored in memory 6, which may include several minutes, hours, days, weeks, months or years of historical data. An average is just one example of a measure of statistical importance (likelihood of stopping), in other examples, other statistical parameters may be employed. In some examples, the driver specific threshold deceleration value for each driver may be modified by each driver. The use of historical data allows drivers to be identified that brake sharply and / or late.In some examples, the historical data is filtered such that the average is calculated from only data indicative of deceleration events that stopped the vehicle 1. Deceleration processes that have not stopped the vehicle 1 can be filtered out.In other examples, the driver-specific threshold deceleration is calculated at block 443 without determining who exactly the vehicle 1 is driving. The threshold calculated in block 443 may be a "default" threshold based on a historical average deceleration of the vehicle 1, or may be based on a threshold preprogrammed by a vehicle user, such as a driver.If block 450 determines that a current decrease in the approach rate exceeds the driver-specific threshold deceleration, then the method 400 proceeds to block 473. This is because it is inferred that the driver is braking or coasting to decelerate the vehicle 1 to stop with the driver's normal deceleration behavior; thus, there is no reason to expect a future rapid increase in the drive request to prevent collision with the object.If the current decrease in the approach rate does not exceed the driver-specific threshold deceleration, for example, if there is no current decrease in the approach rate (vehicle 1 is accelerating or coasting), then the method 400 proceeds to block 460.Determining whether there is a risk includes determining whether the vehicle 1 is being controlled to decrease the approach rate at block 460. In some examples, block 460 evaluates whether the driver's actions indicate that they will increase the average deceleration rate.Examples where it is determined that the vehicle 1 is being controlled to reduce the approach rate include: determining, at block 452, an increase in driver brake actuation from driver action information provided at block 451, such as brake pedal actuation and / or brake pedal pressure information; or determining, at block 454, a decrease in driver power demand from other driver action information provided at block 453, such as accelerator pedal position information.In some examples, the increase in brake actuation and / or decrease in drive power demand is compared to one or more thresholds before determining whether the vehicle 1 is being controlled to decrease the approach rate.If it is determined that the vehicle 1 is being controlled to reduce the approach rate, the method 400 proceeds to block 473. This is because it is inferred that the driver is about to control the vehicle 1 to come to a standstill; thus, there is no reason to expect a future rapid increase in the drive request to prevent collision with the object.If block 460 determines that the vehicle 1 is not being controlled to reduce the approach rate, the second condition of identifying a propulsion request is met; thus, the method 400 of FIG. 4 has ultimately determined that there is a risk.In other examples, additional steps may be provided to more accurately determine whether a risk is present.The final determination that there is a risk means that the driver is expected to increase or do the propulsion request to accelerate the vehicle 1 instead of stopping and this requires the engine 3 to be in the on state to execute the maneuver.In response to method 400 definitely determining that there is a risk, method 400 does not instruct engine 3 to be switched to the off state depending on a current low drive request. Specifically, the method 400 proceeds to block 470 and determines whether the engine 3 is currently in the on state ("active state") depending on a current low propulsion request.If the engine 3 is in the on state, the method 400 proceeds to block 472, which, depending on a current low drive request, prevents the engine 3 from transitioning to the off state ("inactive state").If the engine 3 is currently in the off state, depending on a current low drive request, the method 400 proceeds to block 471, which causes or executes the switching of the engine 3 from the off state to the on state.Thus, the absence of causing the engine 3 to be switched to the off state depending on a current low drive request includes both: preventing the engine 3 from transitioning to the off state; and causing the engine 3 to be switched to the on state when it is currently in the off state.In some examples, the method 400 then returns to blocks 401 and 402 to obtain updated inputs indicative of an updated current external environment proximate to the vehicle 1. The method 400 may return in real-time while the input is updated in real-time.FIG. 5 illustrates a second example of a method 500 related to an overtaking scenario. Except where expressly indicated in the following description, it is noted that method 500 is identical to method 400.The method 500 includes, at block 501, receiving input indicative of the current external environment in the vicinity of the vehicle 1, such as local real-time context data. In some examples, the local real-time context data is as described with respect to block 401. In other examples, the local real-time context data only points to the environment in front of the vehicle 1 and in the path of the vehicle 1. For example, the inputs are received from a forward facing imaging sensor and / or a forward facing LIDAR and / or radar sensor. In some examples, the additional input as described in block 402 is not required.The method 500 continues to block 510. The difference between block 510 and block 410 is that in block 510, the detected object requires the driver to decide whether to slow the vehicle 1 without necessarily stopping it; for example, the object is any moving object, such as another road user. The road user may be a vehicle traveling at a slower speed in front of and in the path of the vehicle 1 moving in the same direction as the vehicle 1.In some examples, as described with respect to block 305, the first condition is satisfied when another vehicle is identified in front of the vehicle 1, for example, by appropriately controlling the threshold to satisfy the first condition.To override the object, the driver would be expected to rapidly increase the propulsion request. However, the driver also has the possibility of slowing the vehicle 1 in order to follow the other road user.In some, but not necessarily all examples, the inputs are processed to monitor the road for passing opportunities. In some examples, the type of road is determined, for example, whether the road is an oncoming road or multi-lane road. In some examples, signs indicating passing rights for the vehicle 1 (road markings and road signs) are recognized.In some examples, the objects represent an active risk because a maneuver is required by the vehicle 1 and / or by the other road user in order to prevent a collision. In some examples, objects representing passive hazards are not detected in block 510. Other aspects of block 510 are as described with respect to block 410.The method 500 continues to block 520. Determining whether there is a risk comprises, in block 520, determining an approach rate between the vehicle 1 and the detected object, wherein the detected object is the other road user. Other aspects of block 520 are as described with respect to block 420.The method 500 continues to block 530. Determining whether there is a risk comprises, in block 530, calculating a threshold change in the approach rate, such as deceleration of the vehicle 1, so as not to pass the other road user. A general or vehicle model specific threshold deceleration may be calculated at block 530 and may have a different value than the threshold deceleration from block 430. Other aspects of block 530 are as described with respect to block 430.The method 500 continues to block 432, which corresponds to the description relating to method 400.The method 500 continues to block 540. Determining whether there is a risk comprises determining whether a current decrease in the approach rate, determined in block 432, for example, exceeds the threshold change, for example, the threshold deceleration calculated in block 530, in block 540. Other aspects of block 540 are as described with respect to block 440.Although not shown in method 500, in other examples method 500 could proceed to a block similar to or corresponding to block 450 of method 400.The method 500 then proceeds to block 460, to block 470, and to one of blocks 471 or 472, each of which corresponds to the description relating to the method 400.FIG. 6 illustrates a third example of a method 600 related to a vehicle-wat scenario. Except where expressly stated in the following description, it is noted that process 600 is identical to process 400.The method 600 includes, at block 601, receiving input indicative of the current external environment in the vicinity of the vehicle 1, such as receiving local real-time context data. The inputs include data that enables information to be determined by processing the data. The inputs specifically relate to the environment in front of the vehicle 1 and / or under the vehicle 1, such as inputs from forward and / or downward facing imaging sensors, and / or forward and / or downward facing LIDAR and / or radar and / or laser sensors. In some examples, the additional input as described in block 402 is not required.In some examples, the inputs include information regarding the road surface, such as whether it is attached or unfastened.The method 600 continues to block 610, 612, or 614. The method 600 executes 610, instead of block 612 or 614, if it is detected that an approaching water region >X cm deep when the vehicle 1 is on a road being mounted.The method 600 executes 612, instead of block 610 or 614, when it is detected that the vehicle 1 is already in >Y cm deep water.The method 600 executes 614 instead of block 610 or 612 when it is detected that an approaching water region >X cm deep and when the vehicle 1 is on an unpaved road.In some examples, the depth X is in the range of 50 cm to 150 cm, such as 90 cm. In some examples, the depth X is vehicle dependent and may represent a maximum safe depth of wake of the specific vehicle 1. The depth X may depend on the size and type of the vehicle 1. the depth X may be at the top of the region for a vehicle 1 having high ride height, such as a sport utility vehicle (SUV). The depth X may be at the lower end of the region for a vehicle 1 which has a comparatively low road clearance.The driver is expected to provide a propulsion request when driving through >X cm deep water to maintain a gas pressure in its exhaust system (not shown) to prevent flooding of the internal combustion engine 3 via its exhaust system. The depth X may be a depth at which flooding of the engine 3 may occur when the engine 3 is in the OFF state, but not when the engine 3 is in the ON state.In some examples, the depth Y is greater than 0 cm and less than the depth X. Puddles may be excluded when the depth Y is greater than a typical depth of a puddle, such as 10 cm.If the driver is not expected to provide a propulsion request, then the driver may wish to stop the vehicle 1 before driving into the water obstacle.Thus, >X cm deep water is an example of an environment that is likely to require deceleration of the vehicle 1.In some examples, as described with respect to block 305, the first condition is satisfied when the >X cm deep water is identified in front of the vehicle 1, for example, by appropriately controlling the threshold to satisfy the first condition.Determining whether there is a risk, as the case may be, at block 610 or 612 or 614 includes detecting, in the current external environment in the vicinity of the vehicle 1, an object corresponding to >X cm deep water in front of the vehicle 1. Other aspects of blocks 610, 612, and 614 are as described with respect to block 410.The >X cm deep water represents a passive risk, since the water is a topographical feature, i.e. a terrain feature which may cause damage to at least the vehicle 1, in this case a flooded driving surface. A flooded driving surface is an example of an environment in which the possibility of an active risk occurring, such as the vehicle 1 being stuck in deep water, is high.The method 600 continues to block 620. Determining whether there is a risk comprises, in block 620, determining an approach rate between the vehicle 1 and the detected object, i.e. the approach rate to the approaching water obstacle. Other aspects of block 620 are as described with respect to block 420.The method 600 continues to block 630. Determining whether there is a risk comprises, in block 630, calculating a threshold change in the approach rate, such as deceleration of the vehicle 1 to stop the vehicle 1 before the vehicle 1 enters the water obstacle. A general or vehicle model specific threshold deceleration may be calculated at block 630. Any threshold deceleration calculated in block 630 may have a different value than the threshold deceleration from block 430. Other aspects of block 630 are as described with respect to block 430.The method 600 continues to block 432, which corresponds to the description relating to method 400.The method 600 continues to block 440, which corresponds to the description relating to method 400.Although not shown in method 600, in some examples method 600 continues with a block similar to or corresponding to block 450 of method 400.The method 600 then proceeds to block 640, which determines whether the driver increases the brake actuation beyond a threshold using information 451 as related to the method 400. If the driver increases the brake actuation beyond the threshold, then the method 600 proceeds to block 473 as described with respect to the method 400. This is because it is inferred that the driver stops the vehicle 1.If the driver does not increase the brake actuation beyond the threshold, then the method 600 proceeds to block 650, which determines whether the driver decreases the accelerator pedal beyond a threshold using information 453 as related to the method 400. If the driver increases the accelerator pedal beyond the threshold, then the method 600 proceeds to block 473 as described with respect to the method 400. This is because it is inferred that the driver stops the vehicle 1.If the driver does not increase the accelerator pedal above the threshold, then method 600 proceeds to block 470 and to either of blocks 471 or 472, as respectively described with respect to method 400.In other aspects, blocks 640 and 650 may be replaced with blocks 452, 454, and 460 as described with respect to block 400.Although the methods 300, 400, 500, and 600 have been described above as separate methods, the methods may be performed as a single method that may be performed simultaneously or simultaneously.The blocks illustrated in Figures 4 to 6 may represent steps in a method and / or portions of code 8 in the computer program 7. The representation of a particular order for the blocks does not necessarily imply that there is a required or preferred order for the blocks, and the order and arrangement of the block may be varied. Moreover, it may be possible that some steps are omitted.For purposes of this disclosure, it is noted that controller / controllers 4 as described herein may each include a controller or computing device having one or more electronic processors. A vehicle 1 and / or a system thereof may comprise a single control unit or an electronic control device, or alternatively different functions of the control device(s) may be implemented or accommodated in different control units or control devices. A set of instructions may be provided that, when executed, causes the controller(s) or controller(s) to perform the control techniques described herein (including the method(s) described). The set of instructions may be embedded in one or more electronic processors, or alternatively, the set of instructions could be provided as software executed by one or more electronic processors. For example, a first controller may be implemented in software executing on one or more electronic processors, and one or more other controllers may also be implemented in software executing on one or more processors, optionally the same one or more electronic processors, as the first controller. It should be appreciated, however, that other arrangements are also useful and, thus, the present disclosure is not intended to limit a particular arrangement. In any case, the set of instructions described above may be embedded in a computer readable storage medium (e.g., a non-transitory volatile storage medium), which may include any mechanism for storing information in a form readable by a machine or electronic processors / computing device, including, without limitation: a magnetic storage medium (e.g., floppy disk); optical storage medium (e.g., CD-ROM); magneto-optical storage medium; read only memory (ROM); random access memory (RAM); erasable programmable memory (e.g., EPROM and EEPROM); flash memory; or electrical or other types of medium for storing such information / instructions.The "enabling" execution of a particular function by a controller 4 includes the controller 4 to directly execute the function, as well as the controller 4 to indirectly execute the function, for example, by causing another controller to directly execute the function. The term "enable" further includes the controller 4 executing the function directly or executing it at a later time, for example, the controller 4 may not execute the function until a condition is satisfied.Although embodiments of the present invention have been described in the preceding paragraphs with reference to various examples, it should be noted that modifications may be made to the given examples without departing from the scope of the claimed invention. For example, it is noted that the engine 3 continues to operate in the off state, but only powers the vehicle periphery, such as an alternator, while being decoupled from one or more vehicle wheels 10 and thus cannot cause the vehicle 1 to accelerate.Features described in the foregoing description may be used in combinations different from the expressly described combinations.Although functions have been described with reference to certain features, these functions are executable by other functions whether or not they have been described.Although features have been described with reference to certain embodiments, these features may be present in other embodiments, whether described or not.While it has been sought in the foregoing specification to draw attention to those features of the invention which have been considered to be particularly important, it should be understood that the Applicant claims protection with respect to any patentable feature or combination of features referred to above and / or illustrated in the drawings, whether or not particular importance has been placed thereon.

Claims

A method of controlling an engine of a vehicle, comprising: receiving at least one input indicative of a current external environment in the vicinity of the vehicle; determining an approach rate between the vehicle and a detected object; determining, in dependence on the at least one input, whether there is a danger, wherein the determining whether there is a danger comprises determining an approach rate between the vehicle and a detected object; determining a current drive request of the vehicle; if it is determined that the current drive request is low, either instructing the engine to switch to an off state if it is determined that there is no danger or not instructing the engine to switch to the off state if it is determined that there is a danger; When it is determined that the current drive request is high, instructing the engine to switch to an on state when the engine is in the off state, wherein the determination of whether there is a danger comprises the determination of the type of intersection that the vehicle approaches, wherein it is determined whether the intersection is an intersection, a circular traffic, or a merging.The method of claim 1, wherein the threshold is calculated as a value from the range of 0.1 g to 0.4 g deceleration.The method according to any one of the preceding claims, wherein when it is determined that the current drive request is low and the engine is in an off state, the method comprises either instructing the engine to switch to the on state when it is determined that there is a danger or not instructing the engine to switch to the on state when it is determined that there is no danger.The method of any preceding claim, wherein determining that there is no risk comprises determining an expected low or no increase in a future propulsion request, and wherein determining that there is a risk comprises determining an expected future propulsion request or an increase in the propulsion request.The method of any preceding claim, wherein the at least one input comprises inputs from a plurality of different sensors.The method of any preceding claim, wherein the at least one input comprises: image data; location data; pulse reflection data; and / or information received from another vehicle and / or infrastructure management system over a wireless network.The method of any preceding claim, wherein determining whether there is a risk comprises detecting, in the current external environment in the vicinity of the vehicle, an environment that is likely to require slowing of the vehicle.The method of any preceding claim, wherein determining whether there is a risk comprises determining an approach rate between the vehicle and a detected object.The method of claim 8, wherein determining that there is a risk comprises determining that the vehicle and the detected object are approaching each other.The method of claim 8 or 9, wherein determining whether there is a risk comprises determining a current decrease in the approach rate.The method of claim 10, wherein determining that there is a risk comprises determining that there is no current decrease in the approach rate or that the current decrease in the approach rate does not exceed a threshold.The method of any of claims 8 to 11, wherein determining whether there is a risk comprises determining whether the vehicle is controlled to decrease the approach rate.The method of claim 12, wherein determining that there is a risk comprises determining that the vehicle is not being controlled to decrease the approach rate.The method of any preceding claim, wherein the risk comprises: an active risk occurring due to actions taken by the driver of the vehicle and / or other road users; and / or a passive risk occurring due to road layout, road infrastructure and / or topography.The method of claim 12, wherein the passive hazard comprises: a terrain feature that may cause damage to at least the vehicle; a road layout feature that provides the priority to other road users; and / or a road infrastructure feature that provides the priority to other road users.The method of claim 15, wherein the terrain comprises a flooded driving surface.The method of any preceding claim, wherein determining whether there is a risk comprises detecting a risk sign using image processing.Method according to one of the preceding claims, wherein the internal combustion engine is decoupled from at least one vehicle wheel in the configured state.A control device comprising means for carrying out the method according to any one of the preceding claims.A vehicle comprising the control apparatus according to claim 19.A computer readable storage medium having stored thereon computer program instructions which, when executed by at least one processor, cause the method of any one of claims 1 to 18 to be carried out.

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