Engine stop/start enablement based on combustion parameters

Apparatuses, systems, methods, and techniques relating to engine start/stop functionality are disclosed. Automatic engine start/stop controls can be disabled during engine operating conditions in which one or more combustion parameters indicate a lack of combustion stability in one or more cylinders of the engine. Engine start/stop controls are enabled when the one or more combustion parameters satisfy combustion parameter conditions indicating combustion stability in the one or more cylinders.

FIELD OF THE INVENTION

The present application relates generally to engine start/stop controls for powertrains and more particularly, but not exclusively to enablement of engine start/stop controls in response to one or more combustion parameters for vehicle powertrains.

BACKGROUND

A common challenge in internal combustion engine (ICE) operation involves the stabilization of fuel combustion during the initial period following the start of a cold ICE. Conditions such as cold intake air running through cold metal channels combining with cold fuel in a cold engine cylinder create combustion problems, such as incomplete combustion and misfire. In addition, excessive cold temperatures in a cooled exhaust gas recirculation (EGR) system can cause water condensation and resulting corrosion problems, so EGR is frequently disabled during cold ICE operating conditions. Similarly, exhaust aftertreatment components typically require elevated temperatures above cold start conditions to function in a desired manner. Cold ICE operation may also render emission control devices ineffective or unusable. As a result, cold engine compensation control of the ICE provides a warm-up operating period critical for efficient combustion as well as emissions compliance. Specialized engine control methods are typically employed to alter the combustion timing, combustion mixture/recipe, and EGR and exhaust aftertreatment usage to mitigate the effects of cold ICE operation under cold engine compensation control operations.

The advent of automatic engine stop/start technology has complicated mitigation strategies to deal with cold engine operation issues due to the desire to automatically (such as without operator input) shut the ICE down as often as possible to avoid ICE idling conditions and save fuel. Start/stop operations can have the effect of prolonging the ICE warm-up period and extending the duration of the symptoms of inefficient operation due to temperatures being too low for the desired operating conditions. Thus, the fuel saving benefits of automatic engine stop/start operations can be offset by the inefficiencies created by prolonged operation of a cold or not fully warmed up ICE.

A typical approach to reducing the impact of cold ICE operations in an automatic engine start/stop system is to simply delay allowing automatic stop/start operations until the ICE temperature, typically determined by engine coolant temperature, exceeds some threshold value. This approach, while simple to implement, does not directly address combustion processes, such as those associated with or that indicate combustion stability, including combustion robustness and optimization, which are critical to engine operation. As a result, the enablement of automatic engine start/stop operations may occur when one or more operating parameters in one or more cylinders indicate combustion instability in the one or more cylinders. Therefore, further improvements in this technology area are needed.

DISCLOSURE OF ILLUSTRATIVE EMBODIMENTS

For the purposes of clearly, concisely and exactly describing exemplary embodiments of the invention, the manner and process of making and using the same, and to enable the practice, making and use of the same, reference will now be made to certain exemplary embodiments, including those illustrated in the figures, and specific language will be used to describe the same. It shall nevertheless be understood that no limitation of the scope of the invention is thereby created, and that the invention includes and protects such alterations, modifications, and further applications of the exemplary embodiments as would occur to one skilled in the art.

SUMMARY

One embodiment of the present disclosure is a unique controls process providing improved automatic engine start/stop functionality. In one form, the controls process delays or disables automatic engine stop/start operations until after combustion parameters of the ICE have stabilized at in-cylinder combustion conditions indicative of normal or nominal operating conditions. In one embodiment, the normal or nominal operating conditions include a lack of misfire and/or incomplete combustion events in the one or more cylinders. This enablement/disablement determination is accomplished by monitoring one or more operating parameters associated with the actual combustion processes in the ICE cylinders, and providing a start/stop enablement command or output when the combustion parameter(s) are within normal or optimal ranges indicative of combustion stability. In further embodiments, one or more operating conditions of the vehicle systems and/or one or more in-cylinder combustion parameters must be satisfied for enablement of automatic engine start/stop controls. Further embodiments, forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

DETAILED DESCRIPTION

With reference toFIG. 1there is illustrated an exemplary vehicle system10. The vehicle system10comprises a plurality of systems including a motor/generator system12, a transmission system14, an engine system16, and an operator controls system18. In one embodiment, these systems are supported on a vehicle chassis (not shown) such as a heavy duty on-highway truck, however, it shall be appreciated that a variety of different types of vehicle chassis are also contemplated. Non-limiting examples of these include on-highway vehicles, off-highway vehicles, construction equipment, mining trucks, buses, and passenger vehicles, among others.

Engine system16may be provided in a variety of forms. In an exemplary embodiment, engine system16includes a compression ignition internal combustion engine17with a turbocharged air intake system50and an exhaust aftertreatment system70. However, non-turbocharged systems are also contemplated.

Intake system50may further be connected to an exhaust gas recirculation system60including, in the illustrated embodiment, and EGR cooler62and an EGR flow control valve64. EGR system60may include an EGR cooler bypass (not shown), an accumulator, mixer or other suitable devices for providing and controlling EGR flow to intake system50. In one embodiment, intake system50includes an intake throttle52and a compressor54to receive and compress intake air and, if an EGR system is provided, the compressed intake air mixes with the EGR flow and is provided to intake manifold56of engine system16.

In the illustrated embodiment, EGR system60is a high pressure EGR system. Other embodiments contemplate low pressure EGR systems in addition to or as an alternative to high pressure EGR systems. In still other embodiments, no EGR system is provided.

Engine17of engine system16includes an engine block with one or more cylinders80that each include a combustion chamber82(FIG. 2) for receiving the charge flow from intake system50. For example, in the depicted embodiment, the engine17includes four cylinders80in an in-line arrangement. However, the engine17may have any different number of cylinders80, as well as cylinders80in a variety of different arrangements. Additionally, as shown inFIG. 2, each cylinder80is sized to accommodate the slideable reciprocating displacement of a piston84along at least a portion of the cylinder80such that the piston84may reciprocate between a top-dead-center position and a bottom-dead-center position. Each of the cylinders80, its respective piston84, and cylinder head86form combustion chamber82. Further, at least a portion of the forces generated by the slideable displacement of the piston84along at least a portion of the cylinder80during combustion events in the combustion chamber82are transmitted to a mechanical drive system. For example, the pistons84are typically operably coupled to a crank shaft88of the engine system16that converts the reciprocal movement of the pistons84of the engine17into rotational movement.

Exhaust system70includes an exhaust manifold72to receive exhaust flow from cylinders80and a turbine74operatively connected to compressor54to form a turbocharger. Multiple turbocharger systems are also possible. Turbine74may include a wastegate bypass75or a controllable inlet (not shown) to control the exhaust flow therethrough. An aftertreatment system76receives the exhaust flow and provides treatment to reduce pollutants in the exhaust before the exhaust is discharged to atmosphere. Any suitable components for aftertreatment system76are contemplated, including particulate filters, selective catalytic reduction (SCR) catalysts, NOx reduction catalysts, oxidation catalysts, three-way catalysts, NOx and/or hydrocarbon storage devices, ammonia oxidation catalysts, catalytic converters, liquid and gaseous ammonia delivery systems, and reductant injectors, for example.

The vehicle system10may also include a waste heat recovery system68associated with engine17that is configured to receive waste heat energy from at least one of engine system16and exhaust system70. Waste heat recovery system68can be, for example, a steam turbine, thermoelectric generator, or other device that converts waste heat energy to usable electric energy for the energy storage system30or that is converted to mechanical energy and applied to the crankshaft.

Motor/generator system12may also be provided in a variety of forms. For example, motor/generator system12may be arranged to provide so-called parallel hybrid systems, series hybrid systems, or in a variety of other configurations, such as shown with motor13a. In the illustrated embodiment, a clutch20is provided between motor/generator system12and engine system16to drive wheels22a,22band allow for selective propulsion of the vehicle system by one of engine system16or motor/generator system12, and by combining outputs thereof. Other arrangements and locations for clutch20are contemplated, including vehicle systems10with no clutch20.

Non-hybrid systems are also contemplated where vehicle propulsion is provided solely by engine system16and motor/generator system12is provided as a starter/accessory motor13bfor operation of vehicle accessories and/or engine starting, but not for propulsion of the vehicle system10. Applications that employ both hybrid motors for propulsion and/or engine starting along with additional motor(s) for accessories and/or engine starting are also contemplated.

Transmission system14may also be provided in a variety of forms including, for example, automatic transmissions, manual transmissions, and automated manual transmissions. Operator controls18typically include an accelerator pedal, a brake pedal, and a parking brake control, among other controls. It is contemplated that various other operator controls may be used depending upon the particular type of vehicle chassis which is utilized and the particular arrangement of the operator cabin. It is further contemplated the operator controls18may be suitable for a self-driving or vehicles that do not include an in-vehicle operator. It is also contemplated that that the controls, control systems, and control devices disclosed herein may be utilized in connection with intelligent transport systems and services which comprises systems that integrate information and communication technologies with transport infrastructure to improve economic performance, safety, mobility and environmental sustainability. In any embodiment, operator controls18are configured and operable to allow operator inputs, whether from within the vehicle or remotely, to start, stop and maneuver the vehicle system10and allow for manual starting and stopping of engine17.

Vehicle system10further includes an energy storage system30which is operatively coupled with motor/generator system12. It is contemplated that energy storage system30may take a variety of forms. For example, energy storage system30may include a battery pack and power electronics for power conversion between energy storage system30and motor/generator system12. Other embodiments contemplate alternate forms of energy storage system30, for example, hydraulic energy storage systems and pneumatic energy storage systems, among others. It shall be appreciated that motor/generator system12may also be configured as either an electrical motor/generator system, or a hydraulic, pneumatic or other type of motor/generator system.

Vehicle system10includes a fuelling system90connected to each of the cylinders80. In certain embodiments, each of the cylinders80includes a direct injector92for providing fueling from a fuel source94of fuelling system90. A direct injector, as utilized herein, includes any fuel injection device that injects fuel directly into the cylinder volume, and is capable of delivering fuel into the cylinder volume of the combustion chamber82when the intake valve(s) and/or exhaust valve(s) are closed. The direct injector92may be structured to inject fuel at the top of the cylinder as shown inFIG. 2or laterally. In certain embodiments, the direct injector92may be structured to inject fuel into a combustion pre-chamber, although a combustion pre-chamber is not required. Each cylinder80may include one or more direct injectors.

The direct injectors92may be the primary or the only fueling device for the cylinders80, or alternatively the direct injectors92may be an auxiliary or secondary fueling device for the cylinders80. In certain embodiments, the direct injectors92are capable of providing the entire designed fueling amount for the cylinders80at any operating condition in which a fuelling command is provided. Alternatively, the direct injectors92may be only partially capable of providing the designed fuelling amount, for example the direct injectors may be capable of providing a designated amount of fuel for a specific purpose.

In still other embodiments, cylinders80include a port injector (not shown) in addition to or alternatively to direct injectors92. In these embodiments, the intake manifold52may be divided (not shown) to separate the charge flows to the respective cylinder or cylinder groups, or the port fuel injectors may be positioned such that no other cylinder in the engine system16is downstream of the port fuel injector, i.e. only the target cylinder is downstream of the port fuel injector.

In certain embodiments, the direct injectors92(or port injectors) of cylinders80operate in response to automatic engine start/stop commands provided by a controller, such as an engine control module, to fuel system90to initiate fuelling in response to an engine start command and to stop fuelling in response to an engine stop command. The stop fuelling commands can be overridden or disabled in response to disablement of automatic engine start/stop control operations according to the disclosure herein.

Vehicle system10further includes a controls system including a start/stop controller100, which may be integrated with an engine control module (ECM), or provided as a stand-alone control device or stand-alone control module. Referring further toFIG. 3, start/stop controller100is configured to receive information from and/or provide control commands to one or more of motor/generator system12, transmission system14, engine system16, operator control system18, clutch20, energy storage system30, intake system50, EGR system60, waste heat recover system68, exhaust system70, fuelling system90and/or cylinders80.

In certain embodiments, start/stop controller100receives information regarding combustion parameters116(FIG. 1) within one or more of the combustion chambers82of one or more of the cylinders80. As shown inFIG. 2, cylinder80includes an in-cylinder sensor89that can measure one or more of, for example, in-cylinder pressure, in-cylinder temperature, in-cylinder gas constituents, cylinder wall temperature, and injector tip temperature. In-cylinder sensor89may be a physical sensor or a virtual sensor.

In addition, the start/stop controller100can receive information regarding operating parameters118associated with one or more of energy storage system30, intake system50, EGR system60, waste heat recovery system68, exhaust system70, fuelling system90, and/or ambient conditions. Operating parameters118may include measurements from sensors (not shown) associated with each of these respective systems12,14,16,18,20,30,50,60,68,70and90. Operating parameters118may also include inputs received from another control module or controller of vehicle system10that provides the operating conditions118of one or more these systems. In a further embodiment, the operating parameters118include an indication of whether engine17is currently being operated by a cold engine compensation control process (i.e. the cold engine compensation control scheme is active), thus indicating the engine17is not at a desired or nominal operating temperature or condition.

At least a portion of the information from these systems and other information inputs may be provided as combustion parameters116and operating parameters118to start/stop evaluation module110of start stop controller100. Certain inputs may be provided directly to start/stop evaluation module110whereas others may be provided using an intermediate transmitting or other device or relay device such as another control module. Start/stop evaluation module110also receives, retrieves, or has stored combustion parameter conditions112and operating conditions114that are used to evaluate one or more combustion parameter116inputs for satisfaction of combustion parameter conditions112, and also evaluates one or more operating parameter118inputs for satisfaction of one or more operating conditions114.

Start/stop controller100also includes an automatic engine start/stop control module120which receives inputs from, for example, motor/generator system12, transmission system14, engine system16, operator controls system18, clutch20, and energy storage system30. The start/stop control module120may be configured in a variety of manners to control automatic engine start events and engine stop events based upon whether criteria for an automatic start event or automatic stop event are present. The start/stop evaluation module110is configured to evaluate one or more combustion parameters116relative to combustion parameter conditions112to selectively enable122or disable124the automatic engine start/stop control module120, depending on whether the combustion parameter conditions112are satisfied. The start/stop evaluation module110can further be configured to evaluate one or more operating parameters118relative to operating conditions114to selectively enable122or disable124the automatic engine start/stop control module120, depending on whether the one or more combustion parameter conditions112are satisfied in addition to one or more operating conditions114being satisfied.

Start/stop controller100may be configured to implement a plurality of controls for vehicle system10including engine start/stop controls. It shall be appreciated that the controls described herein may also be implemented in connection with a variety of additional or alternate control systems including the alternative configurations discussed herein. It shall also be appreciated that the controls described in the present application may be implemented in various combinations of hardware, firmware and/or instructions encoded on a computer readable medium which may be provided in a single microprocessor based controller or control module or, in a plurality of such modules such as a distributed controller system in which a plurality of controllers communicate via a controller-area network (CAN). It shall further be appreciated that start/stop controller100may be one example of a so-called external controller which may communicate start or stop requests to an engine control module (not shown). Such configuration and functionality may be applied in a variety of contexts, for example, when an engine system is provided separately or modularly to interface with a plurality of OEM chassis including different OEM chassis control modules.

For example, start/stop evaluation module110need not be part of a same controller as the automatic engine start-stop control module120. In another example, start/stop evaluation module110is a stand-alone processor or is part of a processor, and includes a communication network interface that is in operative communication with the various systems of vehicle system10to receive the various combustion parameter116inputs and the operating parameter118inputs. The processor includes a memory for storing combustion parameter conditions112and the operating conditions,114, and at least one non-transitory computer readable medium configured to store instructions executable by the processor to selectively enable and disable automatic engine start/stop controls.

One of skill in the art, having the benefit of the disclosures herein, will recognize that the controllers, control systems and control methods disclosed herein are structured to perform operations that improve various technologies and provide improvements in various technological fields. Without limitation, example and non-limiting technology improvements include improvements in combustion performance of internal combustion engines, improvements in emissions performance, aftertreatment system performance, engine torque generation and torque control, engine fuel economy performance, improved durability of exhaust system components for internal combustion engines, and engine noise and vibration control. Without limitation, example and non-limiting technological fields that are improved include the technological fields of internal combustion engines and related apparatuses and systems as well as vehicles including the same.

With reference toFIG. 4there is illustrated a block diagram of exemplary engine start/stop controls130including a start/stop request conditional block132which evaluates whether one or more start/stop request criteria are satisfied. A number of forms and implementations of block132are contemplated. In one example, block132evaluates whether operator conditions, vehicle conditions, engine conditions, engine accessory conditions, and external controller conditions meet certain criteria for automatic engine start and/or automatic engine stop control to occur.

Engine start/stop controls130further include a start/stop combustion conditions conditional block134which evaluates whether one or more combustion conditions are satisfied. A number of forms and implementations of block134are contemplated. In one example, block134evaluates whether in-cylinder and/or other combustion parameters116meet certain combustion parameter conditions112indicative of stability/robustness of the combustion processes within cylinders80to enable automatic engine start/stop control. In still other embodiments, one or more operating parameters118must also satisfy one or more operating conditions114to enable automatic engine start/stop control.

The output of start/stop request conditional block132and the output of start/stop combustion conditions conditional block134are provided to AND operator block136which is configured to perform a logical AND operation relative to the outputs of blocks132and134. The output of AND operator block136is provided to engine start/stop operations block138. When the output of operator block136is true, engine start/stop operations block138sets the logical state of an automatic engine start/stop operational capability as true. When the output of operator block136is false, automatic engine start/stop operations block138sets the logical state of automatic engine start/stop operational capability as false.

Referring toFIG. 5, a flow diagram of a procedure200is shown for enabling or disabling automatic engine start/stop control. Procedure200includes an operation202to determine one or more combustion parameters116. At condition204, procedure200determines whether the one or more combustion parameters116satisfy one or more combustion parameter conditions112. If conditional204is FALSE, procedure200continues at operation206and disables automatic engine start/stop control.

If conditional204is TRUE, procedure200continues at either conditional208or operation210depending on which embodiment is employed. In certain embodiments, the enablement/disablement of automatic engine start/stop operations is based only on the combustion parameter conditions112. In these embodiments, conditional208can be omitted, and automatic engine start/stop control is enabled at operation210. In other embodiments, procedure200continues from conditional204at conditional208to determine if one or more operating conditions114of the vehicle system are satisfied by one or more operating parameters118. If conditional208is FALSE, procedure200continues at operation206to disable automatic engine start/stop control. If conditional208is TRUE, procedure200continues at operation210to enable automatic engine start/stop control.

In certain embodiments, the combustion parameters116include measured or derived in-cylinder combustion parameter(s). In one embodiment, the in-cylinder combustion parameter is determined from a pre-ignition gas operating parameter(s). The pre-ignition gas operating parameter(s) may include one or more of a pressure, a temperature, and constituents of the gas in one or more of the cylinders80. The gas operating parameter(s) are monitored and evaluated by start/stop evaluation module110for indications of a possible incomplete combustion or misfire event in one or more of the cylinders80. The gas operating parameter(s) can be compared to a temperature, pressure and/or gas constituent threshold type of combustion parameter condition(s)112associated with combustion stability. For example, detection of one or more pre-ignition gas operating parameter(s) failing to satisfy in-cylinder combustion parameter condition(s)112result in automatic start/stop operational capability by start/stop control module120being disabled.

In another embodiment, the combustion parameter116is determined from an in-cylinder combustion event. In one embodiment, the in-cylinder combustion event parameter(s) are one or more of a pressure, temperature, or other parameter that occurs during combustion in the cylinder indicating an incomplete combustion or misfire event in one or more of the cylinders80. The in-cylinder combustion event parameter(s) are received and evaluated by start/stop evaluation module110for indications of an incomplete combustion or misfire event, such as by determining whether the pressure or temperature is less than a threshold associated with the in-cylinder combustion parameter(s) failing to satisfy combustion parameter conditions112that indicate combustion stability. For example, detection of one or more combustion event parameter(s) failing to satisfy in-cylinder combustion parameter condition(s)112results in automatic start/stop operational capability by start/stop control module120being disabled.

In yet another embodiment, a cylinder wall temperature is a combustion parameter116monitored by start/stop evaluation module110for an indication of an incomplete combustion or misfire event in one or more of the cylinders80. The cylinder wall temperature parameter can be associated with one or more in-cylinder combustion parameter conditions112such as a cylinder wall temperature threshold that indicates the presence or absence combustion stability. For example, detection of an in-cylinder wall temperature failing to satisfy in-cylinder combustion parameter conditions112such as a temperature threshold results in automatic start/stop operational capability by start/stop control module120being disabled.

In another embodiment, the combustion parameter116is a temperature of a tip96of fuel injector92in cylinder80. Fuel injector tip temperatures are monitored and evaluated by start/stop evaluator module110to determine a fuel injector tip temperature below a certain temperature threshold indicated by the in-cylinder combustion parameter conditions112that indicate the presence or lack of combustion stability. In response to the fuel injector tip temperature being below the threshold and failing to satisfy the in-cylinder combustion parameter conditions112, automatic engine start/stop operational capabilities are disabled.

In further embodiments, start/stop evaluation module110can additionally evaluate one or more operating parameters114for satisfaction of one or more operating conditions118in conjunction with the combustion parameters112in determining whether to enable or disable automatic engine start/stop operational capabilities. For example, in one embodiment, one or more operating parameters of fuelling system90, such as a temperature and/or a pressure of fuel provided to cylinder(s)80, can be monitored for indications of operating parameters failing to satisfy one or more operating conditions114, such as a fuel pressure threshold and/or fuel temperature threshold. In response to the pressure and/or temperature of the fuel failing to satisfy operating conditions112, automatic engine start/stop operational capability is disabled.

In another embodiment, operating parameter118is a measurement of exhaust gas constituents in the exhaust flow of exhaust system70, and the operating condition114is threshold amount of one or more exhaust gas constituents being present or absent. In still other embodiments, the operating parameter118is a temperature condition of one or more components associated with the aftertreatment device(s)76, such as an SCR catalyst, DPF, catalytic converter, etc. The aftertreatment device(s). The operating condition114can be an under-temperature operating condition such as a temperature threshold. Upon detection of such an under-temperature operating parameter and/or in the event the exhaust gas constituents do not satisfy the operating condition114for the aftertreatment device(s)76, automatic engine start/stop operational capability of start/stop control module120can be disabled.

In still another embodiment, operating parameters118of EGR system60are monitored for indications of overcooling and/or condensation operating conditions114. Examples of operating parameters118for EGR system60that can be monitored and compared to associated operating conditions114include one or more of the temperature of the EGR flow or EGR components, coolant temperature of an EGR cooler, constituents of the EGR flow, the EGR flow rate, or other operating parameters. Start/stop evaluation module110provides a disablement command to start/stop control module120to disable automatic engine start/stop operational capability of start/stop control module120in response to the EGR operating parameter(s) filing to meet the EGR operating conditions114.

In still other embodiments, the operating parameter118includes a heat rejection amount from waste heat recovery system68that is monitored and compared to an operating condition114indicative of the amount of heat rejection. Start/stop evaluation module110provides a disablement command to start/stop control module120to disable automatic engine start/stop operational capability of start/stop control module120in response to the measured heat rejection amount failing to satisfy the heat rejection operating condition.

In yet another embodiment, the cold engine compensation controls for engine system16can provide an input to the start/stop evaluation module110indicating whether the cold engine compensation controls of engine system16are active and currently controlling engine operations. When the cold engine combustion controls are active, start/stop evaluation module110provides a command to start/stop control module120to disable automatic engine start/stop operational capability. Furthermore, one or more ambient operating parameters such as temperature and/or humidity can be determined, and can be used to disable operational capability of the engine start/stop control module120in response to one or more ambient operating conditions not being satisfied.

It should be understood that any combination of combustion parameter conditions112can be required to be satisfied in order to enable automatic engine start/start control capabilities. It should further be understood that any combination of or more combustion parameter conditions112and operating conditions114can be required to be satisfied to enable automatic engine start/stop control capabilities. If one or more of these conditions112,114is not satisfied, then engine start/stop capabilities are disabled. When all of the selected conditions112,114are satisfied, or when a designated subset of one or more of the conditions112,114is satisfied, the engine start/stop control capabilities are enables.

According to one aspect of the present disclosure, a method for operating a vehicle that includes an engine system including an internal combustion engine, an operator control system operably coupled to the engine system operable to start and stop the internal combustion engine in response to operator inputs, and a start/stop controller operable to control automatic engine start/stop operations of the internal combustion engine independently of the operator control system is discloses. The method includes determining one or more combustion parameters in one or more cylinders of the internal combustion engine; disabling automatic engine start/stop control of the internal combustion engine by the start/stop controller in response to the one or more combustion parameters not satisfying a combustion parameter condition indicating a combustion stability in the one or more cylinders; and enabling the automatic engine start/stop control of the internal combustion engine by the start/stop controller in response to the one or more combustion parameters satisfying the combustion parameter condition.

In one embodiment, the one or more combustion parameters include an in-cylinder pre-ignition gas parameter and the combustion parameter condition is indicative of an absence of incomplete combustion and misfire events in the one or more cylinders. In a refinement of this embodiment, the in-cylinder pre-ignition gas condition includes at least one of an in-cylinder pressure, an in-cylinder temperature and an in-cylinder gas constituent of the one or more cylinders, and the combustion parameter condition includes at least one of an in-cylinder pressure threshold, an in-cylinder temperature threshold, and an in-cylinder gas constituent amount.

In another embodiment, the one or more combustion parameters includes an in-cylinder combustion parameter and the combustion parameter condition is indicative of an absence of at least one of incomplete combustion and misfire events in the one or more cylinders. In a refinement of this embodiment, the in-cylinder combustion parameter includes at least one of an in-cylinder pressure and an in-cylinder temperature of the one or more cylinders and the combustion parameter condition includes at least one of an in-cylinder pressure threshold and an in-cylinder temperature threshold.

In yet another embodiment, the one or more combustion parameters include a cylinder wall temperature in the one or more cylinders and the combustion parameter condition includes a cylinder wall temperature threshold. In still another embodiment, the method includes disabling automatic engine start/stop control in response to a fuelling system operating parameter providing fuel to the one or more cylinders failing to satisfy at least one of a fuel temperature operating condition and a fuel pressure operating condition.

In another embodiment, the one or more combustion parameters include a fuel injector tip temperature of a fuel injector associated with the one or more cylinders and the combustion parameter condition includes a fuel injector tip temperature operating condition. In yet another embodiment, the method includes disabling the automatic engine start/stop control in response to an EGR system operating parameter indicative of at least one of an overcooling condition and a condensation operating condition in an EGR system connected to the engine system. In a refinement of this embodiment, the EGR system operating parameter includes at least one of an EGR temperature, a coolant temperature of an EGR cooler, an EGR flow rate, and gas constituents in the recirculated exhaust gas.

In another embodiment, the method includes disabling the automatic engine start/stop control in response to determining an exhaust aftertreatment device operating parameter indicative of an under-temperature operating condition of the exhaust aftertreatment device. In yet another embodiment, the method includes disabling the automatic engine start/stop control in response to determining a cold engine compensation control operating parameter of the engine system is in an active operating condition. In still another embodiment, the method includes disabling the automatic engine start/stop control in response to a waste heat recovery system operating parameter indicating of a heat rejection operating condition less than a threshold amount.

In another embodiment, the vehicle further includes a motor/generator system operatively coupled with the engine system, and an energy storage system operatively coupled with the motor/generator system. In yet another embodiment, the combustion parameter condition includes at least one of a single threshold value, a variable threshold value, a range of values, and a derived value. In still another embodiment, the in-cylinder combustion parameter is at least one of a sensed value and a derived value from one or more sensed values.

According to another aspect, a vehicle system includes an internal combustion engine operatively coupled with a transmission system, the internal combustion engine including one or more cylinders for combustion of a fuel. The system also includes an engine start/stop controller in operative communication with the internal combustion engine. The engine start/stop controller is configured to automatically stop and start the internal combustion engine in response to engine start/stop criteria. The engine start/stop controller is further configured to disable the automatic start/stop control of the internal combustion engine in response to one or more in-cylinder combustion parameters not satisfying one or more combustion parameter conditions and to enable the automatic start/stop control of the internal combustion engine by the engine start/stop controller in response to the one or more in-cylinder combustion parameters satisfying the one or more combustion parameter conditions. The one or more combustion parameter conditions are indicative of a combustion stability in the one or more cylinders.

In one embodiment, the system includes a motor/generator system operatively coupled with the engine system and an energy storage system operatively coupled with the motor/generator system.

In another embodiment, the automatic start/stop control of the internal combustion engine is only enabled in response to the engine start/stop controller determining that the in-cylinder combustion parameters satisfy two or more combustion parameter conditions. In a refinement of this embodiment, the two or more combustion parameter conditions include at least two of the following: an in-cylinder pre-ignition gas parameter indicating a lack of incomplete combustion and misfire events in the one or more cylinders; an in-cylinder combustion event parameter indicating a lack of incomplete combustion and misfire events in the one or more cylinders; a cylinder wall temperature in the one or more cylinders exceeding a cylinder wall temperature threshold; and a fuel injector tip temperature of a fuel injector associated with the one or more cylinders exceeding a fuel injector tip temperature threshold.

In another embodiment, the automatic start/stop control of the internal combustion engine is only enabled in response to the engine start/stop controller determining that the one or more in-cylinder combustion parameter satisfy at least one combustion parameter condition and that at least one operating parameter of the vehicle system satisfies at least one operating condition of the vehicle system. In a refinement of this embodiment, the at least one combustion parameter condition includes at least one of the following: an in-cylinder pre-ignition gas parameter indicating a lack of incomplete combustion and misfire events in the one or more cylinders; an in-cylinder combustion event parameter indicating a lack of incomplete combustion and misfire events in the one or more cylinders; a cylinder wall temperature parameter in the one or more cylinders exceeding a cylinder wall temperature threshold; a fuel injector tip temperature parameter of a fuel injector associated with the one or more cylinders exceeding a fuel injector tip temperature threshold. In addition, the at least one operating condition of the vehicle system includes at least one of the following: a fuelling system operating parameter of a fuel system providing fuel to the one or more cylinders satisfying at least one of a fuel temperature operating condition and a fuel pressure operating condition; an EGR operating parameter indicating an absence of an overcooling operating condition or a condensation operating condition in an EGR system; an exhaust aftertreatment device operating parameter indicating an absence of an under-temperature operating condition of an exhaust aftertreatment device; a heat rejection operating parameter of a waste heat recovery system associated with the internal combustion engine indicating a heat rejection operating condition more than a threshold amount; and an ambient operating parameter satisfying an ambient operating condition. In still a further refinement, the in-cylinder pre-ignition gas parameter and the in-cylinder combustion event parameter are determined in response to at least one of an in-cylinder pressure, an in-cylinder temperature, and in-cylinder gas constituents of the one or more cylinders.

In another embodiment, the automatic start/stop control of the internal combustion engine is disabled in response to the engine start/stop controller determining that at least one combustion parameter condition is not satisfied and at least one operating condition of the vehicle system is not satisfied. In a refinement of this embodiment, the at least one combustion parameter condition includes at least one of the following: an in-cylinder pre-ignition gas parameter indicating incomplete combustion and misfire events in the one or more cylinders; an in-cylinder combustion event parameter indicating incomplete combustion and misfire events in the one or more cylinders; a cylinder wall temperature parameter in the one or more cylinders being less than a cylinder wall temperature threshold; and a fuel injector tip temperature parameter of a fuel injector associated with the one or more cylinders being less than a fuel injector tip temperature threshold. In addition, the at least one operating condition of the vehicle system includes at least one of the following: a fuelling system operating parameter of a fuel system providing fuel to the one or more cylinders not satisfying at least one of a fuel temperature operating condition and a fuel pressure operating condition; an EGR operating parameter indicating an overcooling operating condition or a condensation operating condition in an EGR system; an exhaust aftertreatment device operating parameter indicating an under-temperature operating condition of an exhaust aftertreatment device; a heat rejection operating parameter of a waste heat recovery system associated with the internal combustion engine indicating a heat rejection operating condition less than a threshold amount; and an ambient operating parameter not satisfying an ambient operating condition.

According to another aspect, a controller apparatus includes at least one processor, a communication network interface in operative communication with the processor, and at least one non-transitory computer readable medium configured to store instructions executable by the processor to evaluate one or more combustion parameters for selectively enabling and disabling an engine start/stop controls in response to one or more combustion parameter conditions. The one or more combustion parameter conditions are indicative of a combustion stability in one or more internal combustion engine cylinders. The one or more combustion parameters are received by the communication network interface, and automatic start/stop controls of an internal combustion engine are disabled in response to the one or more combustion parameters not satisfying the one or more combustion parameter conditions and the automatic start/stop controls of the internal combustion engine are enabled in response to the one or more combustion parameters satisfying one or more combustion parameter conditions.

In one embodiment, the automatic start/stop control of the internal combustion engine is enabled in response to the processor determining that two or more combustion parameter conditions are satisfied by two or more combustion parameters. The two or more combustion parameter conditions include at least two of the following: an in-cylinder pre-ignition gas parameter indicating a lack of incomplete combustion and misfire events in the internal combustion engine cylinder; an in-cylinder combustion event parameter indicating a lack of incomplete combustion and misfire events in the internal combustion engine cylinder; a cylinder wall temperature parameter in the internal combustion engine cylinder exceeding a cylinder wall temperature threshold; and a fuel injector tip temperature parameter of a fuel injector associated with the internal combustion engine cylinder exceeding a fuel injector tip temperature threshold.

In another embodiment, the automatic start/stop control of the internal combustion engine is disabled in response to the processor determining that the at least one combustion parameter does not satisfy at least one combustion parameter condition and further that at least one operating parameter does not satisfy at least one operating condition. The at least one combustion parameter condition includes at least one of the following: an in-cylinder pre-ignition gas parameter indicating incomplete combustion and misfire events in the internal combustion engine cylinder; an in-cylinder combustion event parameter indicating incomplete combustion and misfire events in the internal combustion engine cylinder; a cylinder wall temperature parameter in the internal combustion engine cylinder being less than a cylinder wall temperature threshold; a fuel injector tip temperature parameter of a fuel injector associated with the internal combustion engine cylinder being less than a fuel injector tip temperature threshold. The at least one operating condition includes at least one of the following: fuelling system operating parameter not satisfying one of a fuel pressure operating condition and a fuel temperature operating condition; an EGR operating parameter indicating a presence of at least one of an overcooling and a condensation operating condition; an exhaust aftertreatment device temperature parameter indicating an under-temperature operating condition; a heat rejection operating parameter indicating a heat rejection operating condition less than a threshold amount; and an ambient operating parameter not satisfying an ambient operating condition.