WO2019125360A1

WO2019125360A1 - Detection of reduced engine idle stop-start performance

Info

Publication number: WO2019125360A1
Application number: PCT/US2017/066991
Authority: WO
Inventors: Jennifer Kay Light-Holets; Joseph P. CHANDRARAJ; Hong Zhang; Andrew GAHIMER; Krishna Chandran VINAY; Shiva K. SOORYAVARAM
Original assignee: Cummins Inc.
Priority date: 2017-12-18
Filing date: 2017-12-18
Publication date: 2019-06-27

Abstract

A system and method identifies degradation or defeat of automatic engine stop/start operations for an engine. For degradation or defeat of automatic engine stop operation, a number of occurrences of a potential engine stop opportunity and a number of actual engine stops for the vehicle over a time period are determined. An engine stop degradation indication is determined by comparing the number of occurrences of the potential engine stop opportunity to the number of actual engine stops over the time period. For degradation or defeat of automatic engine restart operation, an occurrence of an engine restart for the vehicle and an engine restart time period that is measured from the engine restart to when the vehicle speed is greater than a restart threshold vehicle speed is determined. An engine restart degradation indicator is determined by comparing the engine restart time period to a nominal engine restart time period.

Description

DETECTION OF REDUCED ENGINE IDLE STOP-START PERFORMANCE

TECHNICAL FIELD

[0001] The present disclosure generally relates to engine stop/start controls and more particularly, but not exclusively to detection of disablement or reduced performance of the engine stop/start controls.

BACKGROUND

[0002 J Stop/start controls are often configured to utilize opportunities to stop an engine of a vehicle to reduce fuel consumption, and thus reduce fuel costs, while also mitigating emissions. However, many vehicle operators for various reasons prefer not to operate a vehicle that has stop/start controls. Moreover, many vehicle operators will find techniques to disable the stop/start controls. One such disablement technique includes application of a third party system or an after-market product that is applied to an engine. These third party systems enable a driver to keep an engine running without operation of the stop/start controls. One drawback to disablement of the stop/start controls is reduced or eliminated fuel economy savings. Other drawbacks to disablement of the stop/start controls include adverse effects to the engine by continued automatic starting and stopping of the engine.

[0003| Automatic engine stop/start controls can also be defeated by a vehicle operator^'s actions such as purposefully defeating the stop/start control or aggressive driving habits. For example, an aggressive driver can defeat the automatic engine stop/start control by limiting or avoiding vehicle stops and/or commanding or forcing early automatic engine restarts. Fleet owners of multiple vehicles do not want stop/start controls defeated on multiple vehicles since this reduces fuel economy and increase fuel costs.

[0004] Automatic engine stop/start controls can also be defeated by component

degradation or wear that affects operation of the stop/start controls. As such, the engine performance and the stop/start control effectiveness are reduced.

[0005] Thus there is a desire to detect reduced idle stop/start performance due to

installation of third party systems that disable stop/start controls, potential operator defeat or disablement of the stop/start controls, and component degradation. There remains a significant unmet need for the unique apparatuses, methods, systems and techniques disclosed herein.

SUMMARY

[0006] Various aspects for detection of the defeat or degradation of an automatic engine stop control or an automatic engine restart control for an internal combustion engine of a vehicle are disclosed. The vehicle includes an engine control unit configured to automatically stop and restart the internal combustion engine in response to an engine stop signal and in response to an engine start signal, respectively. In one embodiment, a unique system and method for determining an engine stop degradation indication and providing an output of the same to a memory, vehicle operator and/or fleet owner is disclosed. The method includes determining a number of occurrences of a potential automatic engine stop opportunity for the vehicle and determining a number of actual automatic engine stops for the vehicle over a time period. The method includes determining an engine stop degradation indication by comparing the number of occurrences of the potential automatic engine stop opportunity to the number of actual automatic engine stops over the time period, and providing an output of the engine stop degradation indication in response to the comparison.

[0007] Other embodiments include a unique system and method for determining an early engine restart degradation indicator. The method includes determining an occurrence of an early automatic engine restart for the vehicle and determining an automatic engine restart time period that is measured from the automatic engine restart to when the vehicle speed is greater than a restart threshold vehicle speed. The method includes determining an early automatic engine restart degradation indicator by comparing the automatic engine restart time period to a nominal automatic engine restart time period, and providing an output of the early engine restart degradation indicator in response to the early automatic engine restart time period exceeding the nominal automatic engine restart time period.

[0008] This summary is provided to introduce a selection of concepts that arc further described below in the illustrative embodiments. This summary is not intended to identify key or essential features of the claimed subject matter, nor is it intended to be used as an aid in limiting the scope of the claimed subject matter further embodiments. forms, objects, features, advantages, aspects, and benefits shall become apparent from the following description and drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

[0009] The description herein makes reference to the accompanying drawings wherein like reference numerals refer to like parts throughout the several views, and wherein:

[0010] FIG. 1 is a block diagram of an automatic engine stop detection system.

[0011 ] FIG. 2 is a block diagram of an automatic engine restart detection system.

[0012] FIG. 3 is a table including a plurality of operational conditions for vehicle and transmission system conditions for automatic engine stop control.

[0013] FIG. 4 is a table including a plurality of capability conditions for battery system aftertreatment system, engine system, and vehicle and transmission system conditions for automatic engine stop control.

[0014] FIG. 5 is a table including a plurality of operational conditions for vehicle and transmission system conditions for automatic engine restart control.

[0015] FIG. 6 is a table including a plurality of non-opcrational conditions for vehicle and transmission conditions for automatic engine restart control.

[0016] FIG. 7 is a table including a plurality of capability conditions for vehicle and transmission conditions for automatic engine restart control.

[0017] FIG. 8 is a block diagram of a procedure for providing an automatic engine stop degradation indication.

[0018] FIG. 9 is a block diagram of another embodiment procedure for providing an automatic engine stop degradation indication. [0019] F1G. 10 is a block diagram of a procedure for providing an automatic engine restart degradation indication.

DESCRIPTION Of^' ILLUSTRATIVE EMBODIMENTS

[0020] For the purposes of promoting an understanding of the principles of the invention reference will now be made to the embodiments illustrated in the drawings and speci ic language will be used to describe the same. It will nevertheless be understood that no limitation of the scope of the invention is thereby intended, any alterations and further modifications in the illustrated embodiments, and any further applications of the principles of the invention as illustrated therein as would normally occur to one skilled in the art to which the invention relates are contemplated herein.

[0021] Generally, an engine stop/start control feature automatically shuts down an engine at idle opportunities and automatically restarts the engine when the operator needs the vehicle to move. There are two types of reduced stop/start performance that can be flagged. The first type of reduced stop/start performance is when there is no automatic engine shutdown at an idle opportunity. The second type of reduced stop/start performance results in too short engine stop durations because the engine restarts earlier than before the vehicle is required to move. The present disclosure captures situations when vehicle operators purposely defeat the automatic stop/start control feature vehicle operators’ driving habits defeat the automatic stop/start control feature, or component degradation defeats the automatic stop/start control feature. While embodiments arc discussed below using“vehicle”, the present disclosure is applicable to several types of vehicles, such as delivery vehicles, mine haul trucks, mass transit vehicles, vehicle fleets, highway applications or fleets, off-highway applications, industrial equipment, excavators, dozers, etc.

[0022] Moreover, there are various techniques that vehicle operators can employ to cause degraded automatic engine start/stop performance by defeating certain operational conditions that are in the driver’s control required for enablement of automatic engine stop control or to initiate automatic engine restart earlier than necessary. For example, operators can leverage various operational conditions to mimic change of mind events. Operators can also use external devices to interrupt the operational conditions to mimic change of mind events. An example of a change of mind event includes a driver who interrupts the brake signal to mimic a driver’s intent to release the brake just after or prior to the engine shutdown being initiated. In another example of a change of mind event, the driver interrupts the accelerator pedal position signal to mimic that the accelerator pedal was applied just after or prior to the engine shutdown being initiated. In cither of these situations, the fuel system will start or maintain fueling of the engine and the automatic engine shutdown will terminate too soon or will not occur.

[0023] Referring to Fig. 1 , a block diagram of an automatic engine stop detection system 100 to detect an engine stop from an engine running condition is shown. As shown the automatic engine stop detection system 100 of a vehicle includes an engine system 102. an aftertreatment system 104, a vehicle system 106, a transmission system 108. and an engine control unit 1 10. It shall be appreciated that the illustrated configuration and components of the automatic engine stop detection system 100 are but one example and that the disclosure contemplates that a variety of different automatic engine stop detection systems 100 and associated components may be utilized.

[0024] Referring to Fig. 2, a block diagram of an automatic engine restart detection

system 200 to detect an engine restart after an automatic engine shutdown is shown. As shown, the automatic engine restart detection system 200 includes the vehicle system 106, the transmission system 108, and the engine control unit 1 10. It shall be appreciated that the illustrated configuration and components of the automatic engine restart detection system 200 are but one example, and that the disclosure contemplates that a variety of different automatic engine restart detection systems 200 and associated components may be utilized.

[0025] A variety of engines may be used such as, for example internal combustion

engines for engine system 102. Referring to Fig. 1, operation of the engine system 102 or operation of the aftertreatment system 104 may require one or more of capability conditions 1 12 discussed below to be satisfied for an automatic engine stop 120 to occur. Furthermore, operation of the vehicle system 106 or operation of the transmission system 108 requires one or more operational conditions 1 14 that are controlled by the vehicle operator to be met to initiate an automatic engine stop 120, as discussed further below. In order to perform an automatic engine stop 120, both the operational conditions 1 14 and the capability conditions 1 12 must be met. An automatic engine stop 120 may be defeated by the operator or component degradation resulting in the operational conditions not being satisfied when a vehicle stop opportunity otherwise exists.

[0026] Referring to Fig. 2, automatic restart of the engine during operation of the vehicle system 106 may require the satisfaction of non-operational conditions 210, operational conditions 212, and/or capability conditions 214, as discussed below. In order to perform an automatic engine restart 220, the capability conditions 214 must be satisfied and either the non-operational conditions 210 or the operational conditions 212 must be satisfied.

An early automatic engine restart 220 may be initiated by operator behavior or component degradation resulting in the operational conditions being satisfied earlier than needed to move the vehicle using the engine power.

[0027] The engine control unit 1 10, which may be configured to control various

operational aspects of the automatic engine stop detection system 100 and the automatic engine restart detection system 200, may be implemented in a number of ways. The engine control unit 1 10 may execute operating logic that defines various control management, and/or regulation functions. The operating logic may be in the form of one or more microcontroller or microprocessor routines stored in a non-transitory memory dedicated hardware, such as a hardwired state machine, analog calculating machine, various types of programming instructions, and/or other forms as would occur to those skilled in the art.

[0028] Additionally, the engine control unit 110 may be provided as a single component, or a collection of operatively coupled components, and may comprise digital circuitry analog circuitry, or a hybrid combination of both of these types. When of a multi- component form, the engine control unit 1 10 may have one or more components remotely located relative to the others in a distributed arrangement. The engine control unit 1 10 can include multiple processing units arranged to operate independently, in a pipeline processing arrangement, in a parallel processing arrangement, or the like. In one embodiment, the engine control unit 1 10 includes several programmable microprocessing units of a solid-state, integrated circuit type that are distributed throughout the automatic engine stop detection system 100 that each include one or more processing units and non- transitory memory. For the depicted embodiment, the engine control unit 1 10 includes a computer network interface to facilitate communications using standard Controller Area Network (CAN) communications or the like among various system control units. It should be appreciated that the depicted modules or other organizational units of the engine control unit 1 10 refer to certain operating logic performing indicated operations that may each be implemented in a physically separate controller of the engine control unit 1 10 may be virtually implemented in the same controller.

[0029] The description herein including modules and/or organizational units emphasizes the structural independence of the aspects of the engine control unit 1 10 and illustrates one grouping of operations and responsibilities of the engine control unit 1 1 0. Other groupings that execute similar overall operations are understood within the scope of the present application. Modules and/or organizational units may be implemented in hardware and/or as computer instructions on a non-transient computer readable storage medium, and may be distributed across various hardware or computer based components.

[0030] Example and non-limiting implementation elements of modules and/or

organizational units of the engine control unit 1 10 include sensors providing any value determined herein, sensors providing any value that is a precursor to a value determined herein, datalink and/or network hardware including communication chips, oscillating crystals, communication links, cables, twisted pair wiring, coaxial wiring, shielded wiring, transmitters, receivers, and/or transceivers, logic circuits, hard-wired logic circuits, reconfigurable logic circuits in a particular non-transient state configured according to the module specification, any actuator including at least an electrical hydraulic, or pneumatic actuator, a solenoid, an op-amp, analog control elements (springs, filters, integrators, adders, dividers, gain elements) and/or digital control elements.

[0031] The engine control unit 1 10 and/or any of its constituent processors/controllers may include one or more signal conditioners, modulators, demodulators, Arithmetic Logic Units (ALUs), Central Processing Units (CPUs), limiters, oscillators, control clocks, amplifiers, signal conditioners, filters, format converters, communication ports, clamps, delay devices, memory devices, Analog to Digital (A/D) converters, Digital to Analog (D/A) converters, and/or different circuitry or functional components as would occur to those skilled in the art to perform the desired communications. [0032] As shown in Figs. 1 and 2, the engine control unit 1 10 is operably connected to a variety of components of the automatic engine stop detection system 100 and the automatic engine restart detection system 200, including, for example, the engine system 102, the after-treatment system 104, the vehicle system 106, and the transmission system 108, and/or various accessories or systems (not illustrated). Such connections may allow for the communication of information, data, and/or commands between the engine control unit 110 and components of the automatic engine stop detection system 100 that are used in connection with the operation and performance of the automatic engine stop detection system 100. Similar connections may allow for the communication of information, data, and/or commands between the engine control unit 1 10 and components of the automatic engine restart detection system 200 that are used in connection the operation and performance of the automatic engine restart detection system 200.

[0033] Also shown in Figs. 1 and 2, is an external device 130 that can be connected to the engine control unit 1 10 as illustrated, or the external device 130 can be operably connected to a variety of components of the automatic engine stop detection system 100 and the automatic engine restart detection system 200. The external device 130 can be any external device such as a controller configured to interrupt the operational conditions to mimic change of mind events discussed previously.

[0034] Fig. 3 includes a plurality of detailed engine stop operational conditions 300 for the vehicle system 106 and the transmission system 108 that can comprise potential operational conditions 1 14 to be satisfied before an automatic engine stop can occur for detection by the automatic engine stop detection system 100. The plurality of engine stop operational conditions 300 include vehicle system conditions 306 and transmission system conditions 308. The vehicle system conditions 306 may include, for example, the accelerator pedal positon less than or equal to a calibratible threshold that is tolerant of up to 1 kph of noise, the vehicle being stopped from motion, engine speed below a calibratible threshold for a calibratible time after the engine has been running, and vehicle speed less than or equal to a calibratible threshold that is tolerant of up to 1 kph of noise. The transmission system conditions 308 may include, for example, the transmission gear being in a drive position, the transmission gear being shifted from the drive position to a neutral position, the accelerator pedal not being applied, and the service brake or the parking brake being applied. The transmission gear position for manual transmissions in a neutral position can also include a clutch being engaged or not engaged. It should be understood that the vehicle system conditions 306 and the transmission system conditions 308 may include additional conditions other than those listed above.

[0035] The plurality of engine stop operational conditions 300 can be considered for on- highway and off-highway applications. For example, for a vehicle on-highway application wherein the vehicle includes an automatic transmission, the engine stop operational conditions 300 can include the accelerator pedal positon less than or equal to a calibratible threshold, the vehicle speed less than or equal to a calibratible threshold parking brake engaged, service brake engaged, the transmission gear being in a drive position, and the transmission gear being shifted from the drive position to a neutral position. Similarly, for a vehicle on-highway application wherein the vehicle includes a manual transmission, the engine stop operational conditions 300 include all of the above for the automatic transmission except the transmission gear is in neutral with or without the clutch engaged. For a vehicle off-highway application, the engine stop operational conditions 300 include the engine speed below a calibratible threshold tor a calibratible time after the engine has been running. To detect an example of degradation of performance in the vehicle off-highway application, the engine speed is changed to above the calibratible threshold before the calibratible time expires and then the engine speed is quickly dropped back within the calibratible time to below the calibratible threshold. To detect another example of degradation of performance in the vehicle off-highway application, the engine is shutdown but then the engine is restarted and the engine speed remains lower than the calibratible threshold.

[0036] Fig. 4 includes a plurality of engine stop capability conditions 400 for the engine system 102, the aftertreatment system 104, the vehicle system 106, and the transmission system 108 that can comprise capability conditions 1 12 that prevent an automatic engine stop for detection by the automatic engine stop detection system 100. The plurality of engine stop capability conditions 400 include battery system conditions 401 ,

aftertreatment system conditions 404, engine system conditions 402, vehicle system conditions 406, and transmission system conditions 408. It should be recognized that the battery system is a portion of the vehicle system 106 but has been identified separately for case of reference. The battery system conditions 401 that prevent an automatic engine stop may include the battery charge being low, battery voltage being low battery temperature being high, battery sensing system indicates a fault, or communication with battery sensor or controller has failed. The battery system conditions 401 indicate a battery state based on the state of the charge, state of health, and state of function. The aftertreatment system conditions 404 include one or more exhaust aftertreatment components being cold and not at the appropriate temperature, communications with one or more aftertreatment devices having failed, or the exhaust aftertreatment system is currently engaged in a temperature managed operation. The engine system conditions 402 may include engine not being warmed up, engine overheated, or engine sensor has failed. The vehicle system conditions 406 include communication with any vehicle component has failed or at least one sensor that triggers a stop opportunity has failed. The transmission system conditions 408 include transmission has failed or not capable of accommodating engine shutdown. It should be understood that the engine system conditions 402, the aftertreatment conditions 404, the vehicle system conditions 406 and battery system conditions 401 , the transmission system conditions 408 may include additional conditions other than those listed.

[0037] Fig. 5 includes a plurality of engine restart operational conditions 500 for the vehicle system 106 and the transmission system 108 that can comprise the operational conditions 212 for an automatic engine restart for detection by the automatic engine restart detection system 200. The plurality of engine restart operational conditions 500 include vehicle system conditions 506 and transmission system conditions 508. In one form, the vehicle system conditions 506 may include the engine being stopped with the transmission gear being in a drive position. The transmission system conditions 508 may include the transmission gear being shifted from the drive position to a reverse position and the service brake being applied, the accelerator pedal being applied, the service brake being released, and the parking brake being released. In another form, the vehicle system conditions 506 include the engine being stopped with the transmission gear being in a neutral position. Further in this alternative form, the transmission system conditions 508 include the transmission gear being shifted from the neutral position to a reverse position and the service brake being applied, the transmission gear shifted from the neutral position to the drive position with the service brake being applied, and the parking brake being released. It should be understood that the vehicle system conditions 506 and the transmission system conditions 508 may include additional conditions to initiate an automatic engine restart other than those listed herein.

[0038] Fig. 6 includes a plurality of engine restart non-operational conditions 600 for the vehicle system 106 and the transmission system 108 that can comprise the non- operational conditions 210 for an automatic engine restart for detection by the automatic engine restart detection system 200. The plurality of engine restart non-operational conditions 600 include vehicle system conditions 606 and transmission system conditions 608. In one form, the vehicle system conditions 606 include a restart request from the vehicle or a battery state based on a state of charge, state of health and state of function that will cause a restart of the engine. The transmission system conditions 608 include a restart request from the transmission. It should be understood that the vehicle system conditions 606 and the transmission system conditions 608 may include additional engine restart non-operational conditions other than those listed above.

[0039] Fig. 7 includes a plurality of engine restart capability conditions 700 for the

vehicle system 106 and the transmission system 108 that can comprise the capability conditions 214 for an automatic engine restart for detection by the automatic engine restart detection system 200. The plurality of engine restart capability conditions 700 include vehicle system causes 706 and transmission system conditions 708. In one form, the vehicle system conditions 706 include consent from the vehicle. The transmission system conditions 708 include consent from the transmission. It should be understood that the vehicle system conditions 706 and the transmission system conditions 708 may include additional engine restart capability conditions other than those listed.

[0040] Fig. 8 is a block diagram of a procedure 800 for detection of an engine stop

degradation indication by the automatic engine stop detection system 100. The engine stop degradation indication procedure 800 includes a block 802 that determines a number of occurrences of a potential automatic engine stop opportunity for the vehicle that includes the engine system 102, the after treatment system 104, the vehicle system 106, the transmission system 108, and the engine control unit 110, over a time period. The potential engine stop opportunities are described below. Block 804 determines a number of actual engine stops 120 for the vehicle over the time period. As described above providing an automatic actual engine stop 120 includes both the operational conditions 1 14 and the capability conditions 1 12 allowing the automatic engine stop to occur.

However, determining the occurrence of the potential automatic engine stop opportunity only requires the capability conditions 1 12 allow the automatic engine stop to occur since the operator may be attempting to defeat, or the vehicle components may be degraded to defeat, or the external stop/ start controller 130 may be attempting to defeat the operational conditions 1 14. Block 806 determines an engine stop degradation indication by comparing the number of occurrences of the potential engine stop opportunity to the number of actual automatic engine stops over the time period. Block 808 provides an output of the engine stop degradation indication to a memory of control unit 1 10 for storage and evaluation and/or to the user.

[00411 Fig. 9 is a block diagram of another embodiment procedure 900 for detection of an engine stop degradation indication by the automatic engine stop detection system 1 00. Block 902 determines a potential engine stop time that is measured from a start time of each of the potential engine stop opportunities to an end time of each of the potential engine stop opportunities. Block 904 determines an actual engine stop time for the number of actual engine stops. Block 906 determines a ratio of the potential engine stop time to the actual engine stop time. Block 908 compares the ratio to a threshold value. If the ratio is greater than the threshold value, then the engine stop degradation indication 910 is output, stored in a memory of control unit 1 10, or provided to the user. If the ratio is less than the threshold value, then the engine stop degradation indication 900 returns at block 902.

[0042] As described above, block 802 and/or block 902 includes the determination of a potential engine stop opportunity. A potential engine stop opportunity may be determined in response to the engine not being stopped and one or more of (i) detection of the vehicle moving at a creep speed for a time period (ii) detection of the accelerator pedal being engaged while either a parking brake or a service brake is applied (iii) no brake detection when a vehicle speed is below a threshold and a transmission gear is in a drive position or a reverse position, (iv) detection of a transmission gear in a neutral position at a low vehicle speed, and (v) detection of a service brake being released after the service brake was engaged ln one form, the creep speed is less than 5 kilometers per hour and the time period is greater than 1 second. In another form the low vehicle speed is greater than 0 kilometers per hour. The number of occurrences of a potential engine stop opportunity can be summed to determine a potential benefit loss.

[0043] Optionally, the vehicle can be included in a fleet with a plurality of vehicles and the providing the output of the engine stop degradation indication 910 includes providing a plurality of the engine stop degradation indications 910 to a fleet owner of the plurality of vehicles. Some fleet owners or business owners may have concerns that one or more vehicles did not gain as much benefit from engine start-stop operations as other vehicles. By providing the plurality of the engine stop degradation indications 910 from the various vehicles in the fleet to the fleet owner, the fleet owner can determine how likely or often the automatic engine stop detection system 100 detects the engine start-stop operating being defeated which can cause degraded performance of the fuel economy for the vehicles. In one form, one of the plurality of engine stop degradation indications 91 0 is compared to an average of the plurality of the engine stop degradation indications 910 to determine that the one of the plurality of engine stop degradation indications 91 0 is indicating an automatic engine stop degradation event or within an acceptable range of the plurality of engine stop degradation indications 910. Moreover the automatic engine stop detection system 100 may be used with telematics technology, where the fleet owner can use such information to monitor among different vehicles and different operators. Fleet owners can also use such data to encourage operators driving the vehicle in a preferable habit to gain maximum benefits.

[0044] Fig. 10 is a block diagram of detection of a procedure 1000 for providing an

engine restart degradation indication by the automatic engine restart detection system 200. The engine restart degradation indication procedure 1000 includes a block 1002 that determines if an automatic engine restart occurred for the vehicle that includes the engine system 102, the after treatment system 104, the vehicle system 106, the transmission system 108, and the engine control unit 1 10. To initiate an automatic engine restart 220. the engine restart capability conditions 214 must be met and either the engine restart non- operational conditions 210 or the engine restart operational conditions 212 must be met.

If the automatic engine restart 220 occurred, then block 1004 determines an actual engine restart time period that is measured from the time of the engine restart to when the vehicle speed is greater than a restart threshold vehicle speed. If the automatic engine restart 220 did not occur, then the vehicle controller continues to monitor for the occurrence of the automatic engine restart 220. Block 1006 determines if the actual engine restart time period is greater or larger than a nominal engine restart time period. If the actual engine restart time period is greater than the nominal engine restart time period, then an engine restart degradation indicator 1008 can be output or provided. I f the actual engine restart time period is less than the nominal engine restart time period, then no engine restart degradation indicator 1008 is provided. Each occurrence of the engine restart degradation indicator 1008 can be stored in a memory of the control unit 1 10 and evaluated in conjunction with the occurrence of other engine restart degradation indicators 1008 to determine if the automatic engine restart is being initiated too soon or overridden in order to restart the engine to defeat the automatic engine start-stop controls.

[0045] The engine restart degradation indicator is an output that signifies the engine restarted when it may have been possible to have the engine stopped lor a longer period of time. For example, the operator may attempt to override an automatic engine stopped condition by releasing the brake or allowing the vehicle to creep at a low speed in order to restart the engine. This behavior is detected by measuring the time for the vehicle to increase in speed above a nominal vehicle speed associated with a typical or nominal engine restart.

[0046] Optionally, the vehicle can include a plurality of vehicles, and the providing the output of the engine restart degradation indicator 1008 includes providing a plurality of the engine restart degradation indicators 1008 to a fleet owner of the plurality of vehicles. Some fleet owners or business owners may have concerns that some vehicles did not gain as much benefit as other vehicles from engine start-stop operations and the automatic engine restart controls may be being defeated or degraded. By providing the plurality of the engine restart degradation indicators 1008 to the fleet owner lor the various vehicles in the fleet, then the fleet owner can determine how likely the automatic engine start-stop operations are being defeated which can cause degraded performance and loss of fuel economy for the vehicle. In one form, one of the plurality of engine restart degradation indicators 1008 is compared to an average of the plurality of the engine restart degradation indicators 1008 to determine that the one of the plurality of engine restart degradation indicators 1008 is either an automatic engine restart event or within an acceptable range of the plurality of engine restart degradation indicators 1008. Moreover, the automatic engine restart detection system 200 may be used with telematics technology, wherein the fleet owner can use such information to monitor among different vehicles and different operators. Fleet owners can also use such data to encourage operators driving the vehicle in a preferable habit to gain maximum benefits.

[0047] Various aspects of the present disclosure are contemplated. According to one aspect, a method includes determining, over a time period, a number of occurrences of a potential engine stop opportunity for a vehicle including an internal combustion engine and an engine control unit configured to automatically stop and restart the internal combustion engine in response to an engine stop signal and in response to an engine start signal, respectively, determining a number of actual engine stops for the vehicle over the time period, determining an engine stop degradation indication by comparing the number of occurrences of the potential engine stop opportunity to the number of actual engine stops over the time period, and providing an output of the engine stop degradation indication.

[0048] In one embodiment, the method includes determining a potential engine stop time that is measured from a start time of each of the potential engine stop opportunities to an end time of each of the potential engine stop opportunities determining an actual engine stop time for the number of actual engine stops, determining a ratio of the potential engine stop time to the actual engine stop time, and determining the engine stop degradation indication by comparing the ratio to a threshold value.

[0049] In one embodiment, the potential engine stop opportunity includes one or more of (i) detection of the vehicle moving at a creep speed for a time period, (ii) detection of accelerator pedal being engaged while either a parking brake or a service brake is applied, (iii) no brake detection when a vehicle speed is below a threshold and a transmission gear is in a drive position or a reverse position, (iv) detection of a transmission gear in a neutral position at a low vehicle speed, and (v) detection of a service brake being released after the service brake was engaged. In a refinement of this embodiment, the creep speed is less than 5 kilometers per hour and the time period is greater than 1 second. In another refinement of this embodiment, the low vehicle speed is greater than 0 kilometers per hour.

[0050] In another embodiment, the method includes determining the actual engine stop includes both an operational condition and a capability condition being satisfied. In a refinement of this embodiment, the operational condition includes the vehicle being stopped, a transmission gear being in a drive position or in a neutral position an accelerator pedal not being applied, and a service brake or a parking brake being applied ln a refinement of this embodiment, the capability condition includes one or more of (i) a battery system condition, (ii) an after-treatment system condition, (iii) an engine system condition, or (iv) a vehicle and transmission system condition.

[00511 In another embodiment, the method includes determining a potential benefit loss includes summing the number of occurrences of a potential engine stop opportunity.

[0052] In another embodiment, the vehicle includes a plurality of vehicles and the

providing the output of the engine stop degradation indication includes providing a plurality of the engine stop degradation indications to a fleet owner of the plurality of vehicles. In a refinement of this embodiment, comparing one of the plurality of engine stop degradation indications to an average of the plurality of the engine stop degradation indications to determine that the one of the plurality of engine stop degradation indications is either an automatic engine stop degradation event or within an acceptable range of the plurality of engine stop degradation indication. In a further refinement of this embodiment, communicating the automatic engine stop degradation event to the vehicle operator of an associated vehicle.

[0053] In another embodiment, the method includes based on the output of the engine stop degradation indication, determining either (i) an external device configured to disable the engine control unit or (ii) an operator behavior event.

[0054] In another aspect, a method includes determining an occurrence of an engine restart for a vehicle including an internal combustion engine and an engine control unit configured to automatically stop and re-start the internal combustion engine in response to an engine stop signal and in response to an engine start signal, respectively, determining an engine restart time period that is measured from the engine restart to when the vehicle speed is greater than a restart threshold vehicle speed, determining an engine restart degradation indicator by comparing the engine restart time period to a nominal engine restart time period, and providing an output of the engine restart degradation indicator.

[0055] In one embodiment, the method includes determining an actual engine restart opportunity associated with the actual engine restart time period includes a capability condition, and either an operational condition or a non-operational condition having occurred. In a refinement of this embodiment, the operational condition includes one of (i) a transmission gear being shifted from a drive position to a reverse position, (ii) an accelerator pedal being applied, or (iii) a service brake or a parking brake being in a released position. In another refinement of this embodiment, the operational condition includes one of (i) a transmission gear being shifted from a neutral position to either a reverse position or a drive position, or (ii) a parking brake is released. In another refinement of this embodiment, the non-operational condition includes one or more of (i) a battery state based on a state of charge, state of health and state of function, (ii) a restart request from a transmission, or (iii) a restart request from the vehicle. In another refinement of this embodiment, the capability condition includes one or more ol^' a vehicle consent or a transmission consent.

[0056] In one embodiment, the vehicle includes a plurality of vehicles, and the providing the output of the engine restart degradation indicator includes providing a plurality of the output of the engine restart degradation indicators to a fleet owner of the plurality of vehicles. In a refinement of this embodiment, the method includes comparing one of the outputs of the plurality of engine restart degradation indicators to an average of the plurality of the engine restart degradation indicators to determine that the one of the plurality of engine restart degradation indicators is either an automatic engine restart event or within an acceptable range of the plurality of the engine restart degradation indicators. In another refinement of this embodiment, the method includes

communicating the automatic engine restart event to the vehicle operator of an associated vehicle.

[0057] In another aspect, a system, comprises a vehicle including an internal combustion engine and an engine control unit configured to automatically stop and restart the internal combustion engine in response to an engine stop signal and in response to an engine start signal, respectively; the engine control unit further configured to determine, over a time period, a number of occurrences of a potential engine stop opportunity for the vehicle determine a number of actual engine stops for the vehicle over the time period, determine an engine stop degradation indication by comparing the number of occurrences of the potential engine stop opportunity to the number of actual engine stops over the time period, and provide an output of the engine stop degradation indication.

[0058] In one embodiment, the system includes a plurality of vehicles, each of the

vehicles having an engine control unit, where each of the engine control units is further configured to provide the engine stop degradation indication to a fleet owner of the plurality of vehicles. A further embodiment of the system includes each of the engine control units being configured to compare the associated engine stop degradation indication to an average of the plurality of the engine stop degradation indications to determine that the associated engine stop degradation indication is cither an automatic engine stop degradation event or within an acceptable range of the plurality of engine stop degradation indications.

[0059] In another aspect, a system includes a vehicle including an internal combustion engine and an engine control unit configured to automatically stop and restart the internal combustion engine in response to an engine stop signal and in response to an engine start signal, respectively, the engine control unit further configured to determine an occurrence of an engine restart for the vehicle, determine an engine restart time period that is measured from the engine restart to when the vehicle speed is greater than a restart threshold vehicle speed, determine an engine restart degradation indicator by comparing the engine restart time period to a nominal engine restart time period, and provide an output of the engine restart degradation indicator.

[0060] In one form, the system includes a plurality of vehicles, each of the vehicles

having an engine control unit, where each of the engine control units is further configured to provide the output of the engine restart degradation indicator to a fleet owner of the plurality of vehicles. In a further refinement of the system, each of the engine control units is further configured to compare the associated engine restart degradation indicator to an average of the plurality of the engine restart degradation indicators to determine that the associated engine restart degradation indicator is either an automatic engine restart event or within an acceptable range of the plurality of the engine restart degradation indicators. In yet a further refinement the system, each of the engine control units is further configured to communicate the automatic engine restart event to the vehicle operator of an associated vehicle.

[0061] It should be understood that while the use of words such as preferable preferably preferred or more preferred utilized in the description above indicate that the feature so described may be more desirable, it nonetheless may not be necessary and embodiments lacking the same may be contemplated as within the scope of the invention, the scope being defined by the claims that follow ln reading the claims, it is intended that when words such as "a," "an," "at least one," or "at least one portion" are used there is no intention to limit the claim to only one item unless specifically stated to the contrary in the claim. When the language "at least a portion" and/or "a portion" is used the item can include a portion and/or the entire item unless specifically stated to the contrary.

[0062] While the invention has been illustrated and described in detail in the drawings and foregoing description, the same is to be considered as illustrative and not restrictive in character, it being understood that only certain exemplary embodiments have been shown and described. Those skilled in the art will appreciate that many modi fications arc possible in the example embodiments without materially departing from this invention. Accordingly, all such modifications are intended to be included within the scope of this disclosure as defined in the following claims.

[0063] It should be understood that no claim element herein is to be construed under the provisions of 35 U.S.C. § 1 12(f), unless the element is expressly recited using the phrase “means for.” The schematic flow chart diagrams and method schematic diagrams described above are generally set forth as logical flow chart diagrams. As such the depicted order and labeled steps are indicative of representative embodiments. Other steps, orderings and methods may be conceived that are equivalent in function, logic, or effect to one or more steps, or portions thereof, of the methods illustrated in the schematic diagrams. Further, reference throughout this specification to“one

embodiment”,“an embodiment”,“an example embodiment”, or similar language means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the present invention. Thus, appearances of the phrases“in one embodiment”,“in an embodiment”,“in an example embodiment”, and similar language throughout this specification may, but do not necessarily, all refer to the same embodiment.

[0064] Additionally, the format and symbols employed are provided to explain the

logical steps of the schematic diagrams and are understood not to limit the scope of the methods illustrated by the diagrams. Although various arrow types and line types may be employed in the schematic diagrams, they are understood not to limit the scope of the corresponding methods. Indeed, some arrows or other connectors may be used to indicate only the logical flow of a method. For instance, an arrow may indicate a waiting or monitoring period of unspecified duration between enumerated steps of a depicted method. Additionally, the order in which a particular method occurs may or may not strictly adhere to the order of the corresponding steps shown. It will also be noted that each block of the block diagrams and/or flowchart diagrams, and combinations of blocks in the block diagrams and/or flowchart diagrams, can be implemented by special purpose hardware-based systems that perform the specified functions or acts, or combinations of special purpose hardware and program code.

Claims

What is claimed is:

1. A method comprising:

determining, over a time period, a number of occurrences of a potential engine stop opportunity for a vehicle including an internal combustion engine and an engine control unit configured to automatically stop and restart the internal combustion engine in response to an engine stop signal and in response to an engine start signal, respectively;

determining a number of actual engine stops for the vehicle over the time period;

determining an engine stop degradation indication by comparing the number of occurrences of the potential engine stop opportunity to the number of actual engine stops over the time period; and

providing an output of the engine stop degradation indication in response to the comparison.

2. The method of claim 1 , further comprising:

determining a potential engine stop time that is measured from a start time of each of the potential engine stop opportunities to an end time of each of the potential engine stop opportunities;

determining an actual engine stop time for the number of actual engine stops;

determining a ratio of the potential engine stop time to the actual engine stop time; and determining the engine stop degradation indication by comparing the ratio to a threshold value.

3. The method of claim 1 , wherein the potential engine stop opportunity includes one or more of (i) detection of the vehicle moving at a creep speed for a time period, (ii) detection of accelerator pedal being engaged while either a parking brake or a service brake is applied, (Hi) no brake detection when a vehicle speed is below a threshold and a transmission gear is in a drive position or a reverse position, (iv) detection of a transmission gear in a neutral position at a low vehicle speed, and (v) detection of a service brake being released after the service brake was engaged.

4. The method of claim 3, wherein the creep speed is less than 5 kilometers per hour and the time period is greater than 1 second.

5. The method of claim 3, wherein the low vehicle speed is greater than 0 kilometers per hour.

6. The method of claim 1, further comprising:

determining the actual engine stop includes both an operational condition and a capability condition being satisfied.

7. The method of claim 6, wherein the operational condition includes the vehicle being stopped, a transmission gear being in a drive position or in a neutral position, an accelerator pedal not being applied, and a service brake or a parking brake being applied.

8. The method of claim 6, wherein the capability condition includes one or more of (i) a battery system condition, (ii) an after-treatment system condition, (iii) an engine system condition, or (iv) a vehicle and transmission system condition.

9. The method of claim 1 , further comprising:

determining a potential benefit loss includes summing the number of occurrences of a potential engine stop opportunity.

10. The method of claim 1, wherein the vehicle includes a plurality of vehicles; and

the providing the output of the engine stop degradation indication includes providing a plurality of the engine stop degradation indications to a fleet owner of the plurality of vehicles.

1 1. The method of claim 10, further comprising:

comparing one of the plurality of engine stop degradation indications to an average of the plurality of the engine stop degradation indications to determine that the one of the plurality of engine stop degradation indications is either an automatic engine stop degradation event or within an acceptable range of the plurality of engine stop degradation indications.

12. The method of claim 1 1, further comprising:

communicating the automatic engine stop degradation event to the vehicle operator of an associated vehicle.

13. The method of claim 1 , further comprising:

based on the output of the engine stop degradation indication, determining either (i) an external device configured to disable the engine control unit or (ii) an operator behavior event.

14. A method comprising:

determining an occurrence of an engine restart for a vehicle including an internal combustion engine and an engine control unit configured to automatically stop and re-start the internal combustion engine in response to an engine stop signal and in response to an engine start signal, respectively; determining an engine restart time period that is measured from the engine restart to when the vehicle speed is greater than a restart threshold vehicle speed;

determining an engine restart degradation indicator by comparing the engine restart time period to a nominal engine restart time period for the vehicle to exceed the restart threshold vehicle speed; and

providing an output of the engine restart degradation indicator in response to the comparison.

15. The method of claim 14, further comprising:

determining an actual engine restart opportunity associated with the actual engine restart time period includes a capability condition, and either an operational condition or a non- operational condition, having occurred.

16. The method of claim 15, wherein the operational condition includes one of (i) a transmission gear being shifted from a drive position to a reverse position, (ii) an accelerator pedal being applied, or (iii) a service brake or a parking brake being in a released position.

17. The method of claim 15, wherein the operational condition includes one of (i) a transmission gear being shifted from a neutral position to either a reverse position or a drive position, or (ii) a parking brake is released.

18. The method of claim 14, wherein the non-operational condition includes one or more of (i) a battery state based on a state of charge, state of health and state of function, (ii) a restart request from a transmission, or (iii) a restart request from the vehicle.

19. The method of claim 15, wherein the capability condition includes one or more of a vehicle consent or a transmission consent.

20. The method of claim 14, wherein the vehicle includes a plurality of vehicles; and the providing the output of the engine restart degradation indicator includes providing a plurality of the output of the engine restart degradation indicators to a fleet owner of the plurality of vehicles.

21. The method of claim 20, further comprising:

comparing one of the outputs of the plurality of engine restart degradation indicators to an average of the plurality of the engine restart degradation indicators to determine that the one of the plurality of engine restart degradation indicators is either an automatic engine restart event or within an acceptable range of the plurality of the engine restart degradation indicators.

22. The method of claim 21 , further comprising:

23. A system, comprising:

a vehicle including an internal combustion engine and an engine control unit configured to automatically stop and restart the internal combustion engine in response to an engine stop signal and in response to an engine start signal, respectively, wherein the engine control unit is configured to:

determine, over a time period, a number of occurrences of a potential engine stop opportunity;

determine a number of actual engine stops for the vehicle over the time period; determine an engine stop degradation indication by comparing the number of occurrences of the potential engine stop opportunity to the number of actual engine stops over the time period; and

provide an output of the engine stop degradation indication in response to the comparison.

24. The system of claim 23, further comprising a plurality of vehicles, each of the vehicles having an engine control unit configured to provide the engine stop degradation indication to a fleet owner of the plurality of vehicles.

25. The system of claim 24, wherein each of the engine control units is further configured to compare the associated engine stop degradation indication to an average of the plurality ol^' the engine stop degradation indications to determine that the associated engine stop degradation indication is either an automatic engine stop degradation event or within an acceptable range of the plurality of engine stop degradation indications.

26. A system, comprising:

determine an occurrence of an engine restart for the vehicle; determine an engine restart time period that is measured from the engine restart to when the vehicle speed is greater than a restart threshold vehicle speed:

determine an engine restart degradation indicator by comparing the engine restart time period to a nominal engine restart time period for the vehicle to exceed the restart threshold vehicle speed; and

provide an output of the engine restart degradation indicator in response to the comparison.

27. The system of claim 26, further comprising a plurality of vehicles, each of the vehicles having an engine control unit configured to provide the output of the engine restart degradation indicator to a fleet owner of the plurality of vehicles.

28. The system of claim 27, wherein each of the engine control units is further configured to compare the associated engine restart degradation indicator to an average of the plurality of the engine restart degradation indicators to determine that the associated engine restart degradation indicator is either an automatic engine restart event or within an acceptable range of the plurality of the engine restart degradation indicators.

29. The system of claim 28, wherein each of the engine control units is further configured to communicate the automatic engine restart event to the vehicle operator of an associated vehicle.