Method and system for enabling engine start / stop function

Abstract

The present disclosure provides "Methods and systems for enabling engine start / stop functionality". Methods and systems for enabling engine start / stop functionality in a vehicle having removable doors are provided. In one example, a method can include adjusting an engine start / stop strategy in response to detecting that a driver side door of the vehicle is not present. The adjustment to the start / stop strategy can be further modified based on a type of transmission system coupled to the vehicle.

Description

Technical Field

[0001] This specification generally relates to methods and systems for adjusting engine start / stop functions in vehicles with removable doors. Background Technology

[0002] When a vehicle stops mid-journey, such as at a traffic light, the engine may idle for a period of time. To improve fuel efficiency and emissions, vehicle engines can be equipped with a start / stop function to reduce prolonged idling by temporarily shutting off the engine and then restarting it when restarting conditions are met. The engine start / stop function can be activated in the presence of a vehicle operator to ensure that the engine does not stop without operator instruction. By activating the start / stop function in the presence of an operator, the engine can be restarted immediately in response to an increase in engine torque demand.

[0003] Various methods are provided for initiating engine start / stop functions based on the presence of a vehicle operator. In one example, as illustrated in U.S. Patent Application 2012 / 0138006, Gwon et al. teach determining the position of the driver's door and, in response to the driver's door opening, not initiating engine idle-stop even if other conditions for engine idle-stop are met.

[0004] However, the inventors in this paper have recognized the potential problems of such systems. As an example, some vehicles may be equipped with doors that can be removed from the vehicle body by an operator during certain driving situations, such as off-road driving. In the method shown by Gwon et al., the start / stop function cannot be activated during vehicle operation when the door is not present. Fuel consumption may increase and emissions may decrease because the vehicle does not stop during prolonged engine idling. Furthermore, if the engine automatically stops when the driver's door is removed from the body, the driver can leave the vehicle without opening the door. The engine can restart in response to requests for engine power from auxiliary devices such as air conditioning, and the vehicle may be unintentionally propelled in the absence of the driver. Summary of the Invention

[0005] In one example, the aforementioned problem can be addressed by a method for a vehicle comprising: detecting whether a driver's side door is attached or not; selecting a start / stop strategy for the engine propelling the vehicle based on the driver's side door attachment state; and further selecting the start / stop strategy based on the type of transmission connected between the engine and the vehicle. In this way, by detecting each of the door attachment state and the presence of a driver in the vehicle, the engine start / stop function can be optimized for vehicles with removable driver's doors.

[0006] As an example, a vehicle may be equipped with a door control unit (DCU) located outside the driver's door. In response to the fulfillment of idle-stop conditions (such as engine idling exceeding a threshold duration), the DCU can detect the presence of the driver's door based on input from a switch connected to the door connector shunt. The DCU can further detect the presence of the door by sending a signal to the window motor used to operate the driver's side window connected to the door. If the driver's door is detected to have been removed, the controller can determine whether the seatbelt connected to the driver's seat is fastened. If the seatbelt is fastened, it can be inferred that the driver is in their seat even if the driver's door is not present, and engine idle-stop can be initiated by suspending engine combustion. During idle-stop, combustion can be resumed after confirming that the seatbelt is still fastened, in response to the fulfillment of engine restart conditions. The engine start / stop strategy can be further adjusted based on the type of transmission system connected to the vehicle (automatic or manual transmission).

[0007] In this way, fuel efficiency and emissions quality can be maintained by using the engine start / stop function at appropriate times in vehicles with removable doors. By detecting the attachment status of the driver's door, the idle-stop procedure can be appropriately modified even if the driver's door is removed. The technical effect of detecting the driver's presence by determining the status of the driver's seatbelt is that idle-stop or engine restart can be scheduled when the operator's presence in the vehicle is confirmed. By modifying the start / stop strategy based on the vehicle's transmission system, engine efficiency can be improved, thereby enhancing overall fuel efficiency and the operator's driving experience during engine start / stop operations.

[0008] It should be understood that the above-described invention is intended to present, in a simplified form, the selected concepts further described in the detailed embodiments. This does not imply representation of key or essential features of the claimed subject matter, the scope of which is uniquely defined by the claims following the detailed embodiments. Furthermore, the claimed subject matter is not limited to embodiments that address any shortcomings mentioned above or in any part of this disclosure. Attached Figure Description

[0009] Figure 1 An exemplary vehicle system with a removable driver's side door is shown.

[0010] Figure 2 It shows Figure 1 An exemplary engine system for a vehicle system.

[0011] Figure 3A flowchart illustrating an exemplary method that can be implemented to determine the attachment state of the driver's side door is shown.

[0012] Figure 4 A flowchart illustrating an exemplary method that can be implemented for the engine start / stop function is shown.

[0013] Figure 5 An exemplary engine start / stop function for a vehicle with a removable driver's door is shown. Detailed Implementation

[0014] The following description relates to a system and method for enabling engine start / stop function in a vehicle having a removable driver's door. Figure 1 An exemplary vehicle equipped with a removable driver's side door is shown, and Figure 2 An exemplary engine system coupled to a vehicle is shown. The engine controller can be configured to execute control programs, such as... Figure 3 and Figure 4 An exemplary procedure is provided to determine the attachment state of the driver's door and to implement the engine start / stop function based on the attachment state of the driver's door. Figure 5 An exemplary engine start / stop function for a vehicle with a removable driver's side door is shown.

[0015] Figure 1 An exemplary vehicle 101 equipped with a removable door 35 is shown. In one example, vehicle 101 may be a vehicle capable of off-road driving, such as on sand, mud, snow, etc. In another example, vehicle 101 may be a passenger vehicle operated on roads, such as a tour bus equipped to transport passengers. Vehicle 101 may include wheels 55 and a compartment divided into a driver's cab and a passenger compartment. A first door 35 may be attached to the driver's cab next to a seat in which the driver sits during vehicle operation. A second door 36 may be attached to the passenger compartment. In addition... Figure 1 In addition to the door shown, there are other doors leading into the carriage. The first door 35 can be opened using handle 42.

[0016] The first door 35 may be a removable door and can be removed from the vehicle body. Door 35 may be attached to the vehicle body via hinges 16 and 18. Door control unit (DCU) 65 may be attached to onboard controller 12 to facilitate the removal of door 35. In one example, an operator may indicate the intention to remove the door from the vehicle body via switch 24. In one example, switch 24 may be a hard switch attached to a dashboard in the driver's cab. In another example, switch 24 may be a soft switch that can be selected from menu options included in a user interface. In yet another example, switch 24 may be included in a key fob and can be activated from inside or outside the vehicle 101.

[0017] The door connector shunt 38 may include an on / off switch for the door 35. Based on operator input to HMI 24 to remove the door (referred to herein as the door disconnected state), hinges 16 and 18 may be unlocked by controller 12, and the door may be physically removed from the vehicle by the operator. Dashed line 135 shows the outline of the removed driver's door 35. The vehicle can be driven with the driver's door removed. Window 37 may be housed in the first door 35. The window glass of window 37 can be rolled up or down via window motor 39. When the door is removed, window motor 39 may no longer be connected to the vehicle body.

[0018] Engine operation can be adjusted based on the attachment state of the first door 35. The DCU 65 can determine the attachment state of the first door 35. In one example, the door attachment state can be estimated based on the position of a switch in the connector shunt 38 connected to the door; the presence of the door is indicated by the closed position of the switch, and the absence of the door by the open position of the switch. The attachment state of the door 35 is further confirmed based on the presence of a window motor 39 connected to a window 37 housed within the door 35; the presence of the door 35 is confirmed based on the presence of the window motor 39. The presence of the window motor 39 can be detected by transmitting current via the window motor. A seatbelt sensor 28 can be housed in the buckle of a seatbelt connected to the driver's seat. The controller 12 can estimate the seatbelt attachment state based on input from the seatbelt sensor 28. The presence of an operator in the driver's seat can be further estimated based on input from one or more onboard cameras. Figure 3 The details of determining the attachment status of the driver's side door were discussed.

[0019] Additionally, vehicle 101 may include other auxiliary systems, such as air conditioning system 70, which can utilize engine power during operation. During engine idle-stop (when the engine is stationary), if the first door 35 is removed, the engine can be restarted in response to an operator's request for air conditioning, provided the seatbelts are securely fastened. Power from the engine can then be used to operate the compressor of air conditioning system 70.

[0020] Figure 2 This is a schematic diagram showing a vehicle system 200 including a vehicle 101 and an engine system 103. Figure 2 One cylinder of the multi-cylinder engine 10 in the engine system 103 is shown. Figure 2 Vehicle 101 in the text can be Figure 1 The moving vehicle 101, and Figure 2 Engine 10 in the middle can be Figure 1 Engine 10. Engine 10 can be controlled at least in part by a control system including controller 12 and by input from vehicle operator 132 via input device 130. In this example, input device 130 includes an accelerator pedal and a pedal position sensor 134 for generating a proportional pedal position signal PP. Combustion chamber (cylinder) 30 of engine 10 may include combustion chamber walls 32 in which piston 236 is located. Piston 236 may be coupled to crankshaft 40 such that the reciprocating motion of the piston is converted into rotational motion of the crankshaft. Crankshaft 40 may be coupled to at least one drive wheel of the vehicle via an intermediate transmission system. In addition, a starter motor may be coupled to crankshaft 40 via flywheel to enable starting operation of engine 10. The position of crankshaft may be determined via Hall effect sensor (crankshaft signal sensor) 118 coupled to crankshaft 40. In one example, sensor 118, which also functions as an engine speed sensor, may generate a predetermined number of equally spaced pulses with each rotation of crankshaft. Based on the engine speed determined from the input from sensor 118, the controller can determine the corresponding engine sound generated during engine operation.

[0021] Combustion chamber 30 can receive intake air from intake manifold 44 via intake passage 42 and can discharge combustion gases via exhaust passage 48. Intake manifold 44 and exhaust passage 48 can be selectively connected to combustion chamber 30 via corresponding intake valve 72 and exhaust valve 74. In some embodiments, combustion chamber 30 may include two or more intake valves and / or two or more exhaust valves.

[0022] In this example, intake valve 72 and exhaust valve 74 can be controlled by cam actuation via corresponding cam actuation systems 51 and 53. Cam actuation systems 51 and 53 may each include one or more cams and may utilize one or more of a cam profile changing system (CPS), variable cam timing (VCT), variable valve timing (VVT), and / or variable valve lift (VVL) systems, which can be operated by controller 12 to change valve operation. The positions of intake valve 72 and exhaust valve 74 can be determined by position sensors 75 and 77, respectively. In an alternative embodiment, intake valve 72 and / or exhaust valve 74 can be controlled by electric valve actuation. For example, combustion chamber 30 may optionally include an intake valve controlled by electric valve actuation and an exhaust valve controlled by cam actuation (including CPS and / or VCT systems).

[0023] Fuel injector 66 is shown directly coupled to combustion chamber 30 for injecting fuel therein in proportion to the pulse width of the signal FPW received from controller 12 via electronic driver 68. In this way, fuel injector 66 provides so-called direct fuel injection into combustion chamber 30. For example, the fuel injector may be mounted on the side or top of combustion chamber (not shown). Fuel can be delivered to fuel injector 66 via a fuel system (not shown), which includes a fuel tank, fuel pump, and fuel rail. In some embodiments, combustion chamber 30 may optionally or additionally include a fuel injector arranged in intake manifold 44 to provide so-called fuel intake manifold injection into the intake duct upstream of combustion chamber 30.

[0024] The intake passage 42 may include a throttle valve 162 with a throttle plate 64. In this particular example, the position of the throttle plate 64 can be changed by the controller 12 via a signal provided to an electric motor or actuator included with the throttle valve 162, a configuration commonly referred to as electronic throttle control (ETC). In this way, the throttle valve 162 can be operated to change the intake air supplied to the combustion chamber 30 and other engine cylinders. The position of the throttle plate 64 can be provided to the controller 12 via a throttle position signal TP. The intake passage 42 may include an intake air temperature (IAT) sensor 235 and an atmospheric pressure (BP) sensor 138. The IAT sensor 235 estimates the intake air temperature to be used in engine operation and provides a signal to the controller 12. Similarly, the BP sensor 138 estimates the ambient pressure used for engine operation and provides a signal to the controller 12. The intake passage 42 may also include a mass air flow sensor 120 and a manifold air pressure sensor 122 for providing the corresponding signals MAF and MAP to the controller 12.

[0025] Exhaust sensor 136 is shown as being coupled to exhaust passage 48 upstream of emission control device 170. Sensor 136 can be any suitable sensor for providing an indication of exhaust air-fuel ratio (AFR), such as a linear oxygen sensor or UEGO (universal or wide-range exhaust oxygen sensor), dual-state oxygen sensor or EGO, HEGO (heated EGO), nitrogen oxide (NOx), hydrocarbon (HC), or carbon monoxide (CO) sensor.

[0026] Emission control device 170 is shown arranged along exhaust passage 48 downstream of exhaust sensor 136. Device 170 may be a three-way catalytic converter (TWC), a NOx trap, various other emission control devices, or combinations thereof. In some embodiments, emission control device 170 can be periodically reset by operating at least one cylinder of the engine within a specific air-fuel ratio during operation of engine 10. An oxidation catalyst (not shown) may also be included upstream of emission control device 170 and closely coupled to engine 10.

[0027] Furthermore, the exhaust gas recirculation (EGR) system 140 can guide a desired portion of the exhaust gas from the exhaust passage 48 to the intake manifold 44 via the EGR passage 143. The amount of EGR supplied to the intake manifold 44 can be varied by the controller 12 via the EGR valve 145. Additionally, an EGR sensor 146 can be disposed within the EGR passage 143 and can provide indications of one or more of the exhaust gas pressure, temperature, and component concentration. A linear oxygen sensor 172 can be positioned in the intake passage downstream of the intake throttle valve to facilitate EGR regulation. Under certain conditions, the EGR system 140 can be used to regulate the temperature of the air-fuel mixture within the combustion chamber, thus providing a method for controlling ignition timing during certain combustion modes. Furthermore, under certain conditions, a portion of the combustion gases can be retained or trapped in the combustion chamber by controlling the exhaust valve timing (e.g., by controlling a variable valve timing mechanism).

[0028] Vehicle 101 may include an instrument panel 76. Switch 24 may be connected to the instrument panel to allow the vehicle operator to request the removal of the driver's door. (See also: [link to relevant documentation]) Figure 1 The described door connector shunt, including an on / off switch for the driver's door, can unlock the hinges that attach the door to the vehicle body. Once the hinges are unlocked, the operator is able to physically remove the door.

[0029] During periods when the operator's torque demand decreases below a threshold, such as when the vehicle is stopped at a traffic signal, the engine can idle until the torque demand increases. Prolonged idling can adversely affect fuel economy and emissions. As an example, the engine idle-stop condition can be met when the vehicle is operating below a threshold speed and braking is applied.

[0030] In response to the fulfillment of an engine idle-stop condition, an automatic start / stop operation (also referred to herein as engine idle-stop or engine start / stop) can be performed to reduce the duration of engine idling. For example, if it is determined that the engine idle-stop condition is met, a first strategy can be selected for engine start / stop in response to the presence of a door, and a second strategy can be selected for engine start / stop in response to the absence of a door, wherein the first strategy includes idling-stopping the engine when the door is locked, and wherein the second strategy includes idling-stopping the engine regardless of the door lock status. The second strategy may also include each of the following: suspending engine combustion in response to both the engine idling duration exceeding a threshold and the seatbelt being fastened to a seat occupied by an operator during driving of the vehicle; and continuing engine combustion in response to both the engine idling duration exceeding the threshold and the seatbelt being unfastened. The second strategy may also include restarting engine combustion in response to one or more of the following: shifting from a driving gear in an automatic transmission system, unfastening the seatbelt, releasing the brake pedal in a vehicle equipped with an automatic transmission system, and engaging the clutch pedal in a vehicle equipped with a manual transmission system. Furthermore, in the second strategy, during engine combustion interruption, in response to an increase in engine power demand in a vehicle equipped with a manual transmission system and with the clutch pedal disengaged, the operator may be instructed to engage the clutch pedal, and engine combustion interruption may be maintained until the clutch pedal is engaged. During engine combustion interruption, the vehicle operator may be instructed via HMI 24. Moreover, the operator may be notified via HMI 24 during situations such as when engine idle-stop is disabled in response to the absence of the driver's side door and the seatbelt being unfastened. Figure 4 The details of executing the engine start / stop function when it is confirmed that the driver's door has been removed are discussed.

[0031] Figure 1 and Figure 2The controller 12 shown is a microcomputer, including a microprocessor unit 102, an input / output port 104, an electronic storage medium for executable programs and calibration values ​​(shown in this particular example as a read-only memory chip 106), a random access memory 108, a keep-alive memory 110, and a data bus. In addition to the signals previously discussed, the controller 12 can also receive various signals from sensors coupled to the engine 10, including measurements of exhaust AFR and intake AFR from oxygen sensors 126 and 172, intake mass airflow (MAF) from mass airflow sensor 120; engine coolant temperature (ECT) from temperature sensor 112 coupled to cooling sleeve 114; surface ignition sensing signal (PIP) from Hall effect sensor 118 (or other type of sensor) coupled to crankshaft 40; throttle position (TP) from throttle position sensor; absolute manifold pressure signal (MAP) from sensor 122; vehicle angular velocity from yaw rate sensor; and seat belt status from seat belt sensor 28. Controller 12 can generate an engine speed signal (RPM) from the signal PIP. The manifold pressure signal (MAP) from the manifold pressure sensor can be used to provide an indication of vacuum or pressure in the intake manifold. Note that various combinations of the aforementioned sensors can be used, such as having a MAF sensor but not a MAP sensor, or vice versa. During stoichiometric operation, the MAP sensor can provide an indication of engine torque.

[0032] The storage medium read-only memory 106 can be programmed with computer-readable data representing non-transitory instructions executable by processor 102 for performing the methods described below and other anticipated but not specifically listed variations. As described above, Figure 2 Only one cylinder of a multi-cylinder engine is shown, and each cylinder may similarly include its own set of intake / exhaust valves, fuel injectors, spark plugs (not shown), etc.

[0033] Controller 12 from Figure 1 Various sensors receive signals and employ Figure 1 Various actuators adjust engine operation based on received signals and instructions stored in the memory of controller 12. In one example, in response to the engine load being below a threshold for a duration exceeding a threshold in a vehicle with a driver's door attached, the controller can initiate engine idle-stop by sending a signal to fuel injector 66 to suspend fuel injection into the engine cylinders. In another example, in response to the engine load being below a threshold for a duration exceeding a threshold in a vehicle with a driver's door attached, the controller can confirm the presence of the driver via input from seatbelt sensor 28 and then initiate engine idle-stop.

[0034] In some examples, vehicle 101 may be a hybrid vehicle having multiple torque sources available for one or more wheels 55. In other examples, vehicle 101 may be a conventional vehicle with only an engine or an electric vehicle with only one or more electric motors. In the example shown, vehicle 101 includes an engine 10 and an electric motor 52. The electric motor 52 may be a motor or a motor / generator. When one or more clutches 56 are engaged, the crankshaft 40 of engine 10 and the electric motor 52 are connected to the wheels 55 via a transmission 54. In the depicted example, a first clutch 56 is disposed between the crankshaft 40 and the electric motor 52, while a second clutch 56 is disposed between the electric motor 52 and the transmission 54. Controller 12 may send signals to the actuators of each clutch 56 to engage or disengage the clutch, thereby connecting or disconnecting the crankshaft 40 from the electric motor 52 and its connected components, and / or connecting or disconnecting the electric motor 52 from the transmission 54 and its connected components. In one example, engaging the clutch includes an operator depressing the clutch pedal with their foot, while disengaging the clutch includes removing the foot from the clutch pedal. The transmission 54 may be a gearbox, a planetary gear system, or other type of transmission. The powertrain can be configured in various ways, including parallel, series, or series-parallel hybrid vehicles. In one example, transmission 54 could be an automatic transmission system, where the operator does not need to manually specify the gear ratios during forward vehicle propulsion. In an automatic transmission system, engine power is transmitted to the wheels via a torque converter in the absence of a physical clutch pedal in the cab. In another example, transmission 54 could be a manual transmission system, where the operator can manually shift gears by engaging the clutch during forward vehicle propulsion, with the clutch pedal located in the cab.

[0035] The motor 52 receives electrical power from the traction battery 58 to provide torque to the wheel 55. For example, during braking operations, the motor 52 can also be used as a generator to provide electrical power to charge the traction battery 58.

[0036] In this way, Figures 1 to 2 The components implement a system for a hybrid vehicle system, the system comprising: a controller having computer-readable instructions stored in a non-transitory memory to perform the following operations: estimating the attachment state of a door based on the position of a switch coupled to a door connector shunt and the presence or absence of current flowing through a motor coupled to a window housed in a door of the vehicle; and, in response to the absence of the door in the vehicle body and the vehicle being stationary for a duration exceeding a threshold, estimating the attachment state of a seatbelt via a seatbelt sensor coupled to a buckle of the seatbelt, and selectively initiating an engine idle-stop based on the attachment state of the seatbelt and the type of transmission system coupled to the vehicle.

[0037] Figure 3 An exemplary method 300 is shown for determining whether a door next to the driver's seat is attached or not, and modifying the engine start / stop function based on the door's attachment state. This can be performed by a controller based on instructions stored in the controller's memory and in conjunction with sensors from the engine system (such as those mentioned above). Figure 1 and Figure 2 The sensor described receives signals to execute instructions for performing method 300 and the remaining methods included herein. According to the methods described below, the controller can employ the engine actuator of the engine system to adjust engine operation.

[0038] At point 302, current vehicle and engine operating conditions can be estimated and / or measured. These conditions may include, for example, operator torque demand, engine speed, vehicle speed, engine temperature, engine load, environmental conditions (such as ambient humidity, temperature, and atmospheric pressure), exhaust temperature, manifold pressure, manifold airflow, battery state of charge, etc. Furthermore, road conditions can be estimated via one or more of a yaw rate sensor and an onboard camera. In one example, the controller can determine whether the vehicle is traveling in off-road conditions (such as on sand, snow, etc.).

[0039] At 304, the procedure includes determining whether an engine idle-stop condition is met and whether an engine spin-down can be initiated. In one example, the condition for an engine idle-stop may include engine idling for an extended period exceeding a threshold duration. Engine idling can occur when the engine load is below the threshold (e.g., when the vehicle is stationary) or when the vehicle is in a stopped traffic situation. Operating the engine at idle speed for an extended period exceeding the threshold duration may result in increased fuel consumption and increased exhaust emission levels. The threshold duration may be based on the fuel level in the fuel tank. As an example, if the fuel level in the fuel tank is below a threshold level, the threshold duration may be reduced so that no additional fuel is consumed due to engine idling. In another example, the condition for an engine idle-stop may include vehicle operation below a threshold speed due to applied braking. Idle-stop during non-zero speed conditions may be referred to as coasting idle-stop, such as when the vehicle is coasting with the operator's foot off the pedal.

[0040] Engine idle-stop conditions may also include a battery state of charge (SOC) greater than a threshold. The controller can check the battery SOC against a preset minimum threshold, and if it determines that the battery SOC is charged to at least 30%, automatic engine stop can be activated. Confirmation of engine idle-stop conditions may also include an indication that the starter / alternator motor is ready. The status of the air conditioning can be checked, and before initiating engine idle-stop, it can be verified that the air conditioning has not requested a restart of the engine (if air conditioning is required, a restart can be requested). In one example, air conditioning may be required if the temperature in the passenger compartment rises above a desired temperature indicated by the operator. In another example, the operator can initiate air conditioning operation by sending a command to the controller via a switch on the instrument panel. Intake air temperature can be estimated and / or measured to determine if it is within a selected temperature range. In one example, the intake air temperature can be estimated via a temperature sensor located in the intake manifold, and engine idle-stop can be initiated when the intake air temperature is above a threshold temperature. Furthermore, engine temperature can be estimated and / or measured to determine if it is within a selected temperature range. In one example, engine temperature can be inferred from engine coolant temperature, and engine idle-stop can be initiated when the engine coolant temperature is above a threshold engine temperature. The torque requested by the driver can be estimated, and confirmation of engine idle-stop can be initiated in response to the requested torque being below a threshold. Furthermore, emission control devices connected to the engine's exhaust manifold can be analyzed to determine if a request for engine restart has been made.

[0041] Engine idle-stop conditions can be based on the lock status of the doors. The controller can detect whether all doors in the vehicle are locked and whether any door is not half-open. Furthermore, engine idle-stop conditions can also depend on the road conditions under which the vehicle is operating. If the vehicle is traveling in off-road conditions (such as on sand or snow), engine idle-stop cannot be initiated. In off-road conditions, when the vehicle is maneuvering on uneven surfaces, engine torque can be continuously requested due to the higher torque demand.

[0042] If it is determined that the engine idle-stop condition is not met, then at 306, the current engine operation can continue without initiating an engine start / stop operation, such as keeping the engine running while the cylinders are burning fuel.

[0043] If the engine idle-stop condition is determined to be met, then at point 308, it can be controlled via the door control unit (such as...). Figure 1 The DCU (Device Control Unit) is used to estimate the attachment state of the driver's door. The DCU can be part of the vehicle control system and can be housed in the driver's door outside the vehicle. Doors near the driver's seat (such as...) Figure 1 The vehicle door 35 (the door used by the vehicle operator to enter the vehicle) can be detached from the vehicle body. The vehicle can continue to be operated (pushed forward) even with the door detached. Estimating the attachment state of the driver's door includes estimating the state of the door connector shunt connected to the driver's door at 309. A driver's door on / off switch can be built into the shunt. When the driver's door is detached, the switch can be in the off state, and when the driver's door is attached to the vehicle body, the switch can be in the closed state. Estimating the attachment state of the door also includes estimating the state of the motor connected to the window housed in the driver's door at 310. If the driver's door is detached, the window is also removed from the vehicle body. The window motor can be connected to the window to facilitate the movement of the window glass (rolling up and down). The DCU can send signals (such as current) to the window motor to detect the presence of the motor. When the driver's door is detached, current cannot flow through the window motor because the window motor is no longer connected to the DCU, and current can flow through the window motor when the driver's door is attached to the vehicle body.

[0044] At 312, the procedure includes determining whether the driver's door is attached to the vehicle body. If each driver's door shunt connector switch is closed and current can be directed through the driver's side window motor, the driver's door can be confirmed as attached. If it is determined that the driver's door shunt connector switch is open and / or current cannot be directed through the driver's side window motor, it can be inferred that the driver's door is not attached. If the controller cannot determine the attachment status of the driver's door (due to a fault during door attachment status determination), such as if the shunt connector and / or window motor degrades, the controller can assume the driver's door is not attached and perform engine start / stop as appropriate for cases where the driver's door has been removed.

[0045] In the absence of the driver's door, at point 322, the modified strategy can be used for engine start / stop. In the modified engine start / stop method, because the driver's door is removed, the controller cannot check whether the driver's door is in the locked position, and if all other conditions for engine idle-stop are met, the engine can be idle-stopped. Figure 4 The details of the modification method were discussed.

[0046] In one example, for a vehicle equipped with an automatic transmission, during the driver's door removal state (also referred to herein as the door open state), the engine can idle-stop only if the transmission is in drive (not neutral, park, or reverse) and the brake pedal is engaged. As an example, engaging the brake pedal includes the operator pressing the brake pedal with their foot, while disengaging the brake pedal includes removing the foot from the brake pedal. In another example, during the driver's door open state, for a vehicle equipped with an automatic transmission, engine idle-stop can be performed if the transmission is in drive, neutral, or park. In yet another example, during the driver's door open state, for a vehicle equipped with a manual transmission, engine idle-stop can be performed only if the transmission is in neutral and the clutch pedal is released (the operator's foot is not pressed on the clutch pedal).

[0047] If it is determined that the driver's door shunt connector switch is closed and current can be directed through the driver's side window motor, it can be inferred that a driver's door is attached. In response to confirmation of a driver's door attachment and the fulfillment of the engine idle-stop condition, at point 314, combustion can be suspended to shut down the engine. To suspend combustion, fuel and spark supply to the engine cylinders can be suspended. The controller can send a signal to one or more fuel injectors connected to the engine cylinders to stop fuel injection to each cylinder. Additionally, cylinder valve operation can be suspended. Once combustion is suspended, the engine can decelerate and the engine speed can be gradually reduced to zero. A message indicating that the engine has idled-stopped can be displayed to the vehicle operator via a human-machine interface (HMI) connected to a vehicle system (such as on the vehicle's dashboard). If the driver's door is removed during engine shutdown, the procedure can proceed directly to... Figure 4 Step 408 in the process.

[0048] At 316, the procedure includes determining whether engine restart conditions are met. In one example, engine idle-stop followed by engine idle-start (restart) conditions may include an increase in engine load. In one example, the controller may determine whether the brake pedal has been released. The accelerator pedal position may also be determined, for example, via a pedal position sensor, to determine whether the accelerator pedal has been engaged in addition to releasing the brake pedal. For vehicles equipped with an automatic transmission system, the position of the transmission system may also be determined, and if the transmission shifts from a driving position to any other position (such as neutral, park, and reverse), a request for engine restart may be made. For vehicles equipped with an automatic transmission system, the position of the transmission system may also be determined, and if the gear position shifts from neutral to any other gear (such as 1st, 2nd, 3rd, etc.) and / or the clutch pedal is engaged, a request for engine restart may be made.

[0049] The status of the air conditioning can be checked to verify whether a restart request has been made, which can be done when the air conditioning is needed. The battery's SOC can be estimated to determine if it is below a predetermined threshold. In one example, it might be expected that the battery is charged to at least 30%. Therefore, an engine start can be requested to charge the battery to the desired level.

[0050] Engine restart conditions may also include a request from the emission control unit to restart the engine. In one example, the emission control unit temperature can be estimated and / or measured using a temperature sensor, and if the temperature is below a predetermined threshold, engine restart can be requested. The vehicle speed can be estimated and assessed whether it is above a predetermined threshold. For example, if the vehicle speed is above the threshold (e.g., 3 mph), engine restart can be requested. It can be determined whether the engine's electrical load is above a predetermined threshold, and engine restart can be requested in response (e.g., to reduce battery consumption). In one example, the electrical load may include one of various user-operated accessories (such as mobile phones, laptops, etc.), defrosters, windshield wipers, music systems, navigation systems, electric air conditioning, etc. Furthermore, if the vehicle is off-roading and operating on uneven surfaces such as sand or snow (which increases the engine torque demand), engine restart conditions may be met.

[0051] If it is determined that the engine restart conditions are not yet met, then at point 318, the engine can remain off and stationary without resuming combustion. The engine can remain stationary until the engine restart conditions are met.

[0052] If the engine restart conditions are determined to be met, the engine can be restarted at 320. During engine restart, combustion can be restored by initiating refueling into the engine cylinders. The controller can send a signal to the actuator connected to the starter motor to use energy from the starter motor to rotate the starter engine until the engine idle speed is reached. The vehicle battery can provide power to the starter motor. Furthermore, the controller can send a signal to one or more fuel injectors connected to the engine cylinders to restart fuel injection into each cylinder. Additionally, the controller can send a signal to the spark plugs connected to each cylinder to activate the spark. During engine restart, the transmission position can be maintained at the current transmission position (such as drive, neutral, or reverse).

[0053] In this way, in vehicles equipped with manual transmission systems, combustion in one or more engine cylinders can be suspended in response to each of the following: the absence of a door in the vehicle body, the vehicle remaining stationary for a threshold duration, the seatbelts being fastened, the transmission being in neutral, and the clutch pedal connected to the passenger compartment being released. In vehicles equipped with automatic transmission systems, combustion in one or more engine cylinders can be suspended in response to each of the following: the absence of a door in the vehicle body, the vehicle remaining stationary for a threshold duration, the seatbelts being fastened, the transmission being in drive, and the clutch pedal connected to the passenger compartment being engaged.

[0054] Figure 4 An exemplary method 400 for engine start / stop function is shown when the driver's door is removed from the vehicle. Method 400 can be as follows: Figure 3 This is part of the method 300 described herein, and can be performed in step 322 of method 300. As shown in method 300, method 400 can be performed in response to the satisfaction of the engine idle-stop condition and upon confirmation that the vehicle driver's door is in a disassembled state.

[0055] At 402, the procedure includes determining whether the driver's seatbelt is fastened. The controller can be activated via a seatbelt sensor (such as...) housed in the buckle of the driver's seatbelt. Figure 1 The seatbelt sensor 28 in the vehicle estimates the attachment status of the seatbelt connected to the driver's seat. When the seatbelt is fastened, the seatbelt sensor can detect a "closed" state, indicating the presence of an operator in the driver's seat. Conversely, when the seatbelt is unfastened, the seatbelt sensor can detect a "disconnected" state, indicating that an operator may not be present in the driver's seat. The presence of an operator in the driver's seat can be further estimated based on input from one or more onboard cameras. However, even if an operator is present in the driver's seat, if the seatbelt is not fastened, it can be inferred that the operator may not be ready to operate the vehicle.

[0056] If it is determined that the seatbelt is not fastened, it can be inferred that the operator may not be in the driver's seat and may not be able to actively operate the vehicle and / or command any changes to engine operation. Therefore, any changes to the current vehicle and engine operation may not be expected. At 404, even if the engine idle-stop condition is met, the engine can remain running while burning fuel in the cylinders.

[0057] If it is determined that the seatbelt is fastened, it can be inferred that the vehicle can be operated with an operator in the driver's seat and the driver's door removed. At 406, combustion can be interrupted to shut off the engine. The controller can send a signal to one or more fuel injectors coupled to the engine cylinders to stop fuel injection into each cylinder. Additionally, spark plugs can be disabled. A message indicating that the engine has idled-stopped can be displayed to the vehicle operator via a human-machine interface (HMI) coupled to vehicle systems (such as on the vehicle's dashboard).

[0058] At 408, the procedure includes determining whether an engine restart condition is met. An engine restart condition may include releasing the seatbelt. If the operator releases the seatbelt during an engine idle-stop condition, the engine restart condition is met. Releasing the seatbelt can be interpreted as an indication that the operator intends to leave the vehicle. When the driver's door is removed (disconnected), if the seatbelt becomes unfastened, the system should automatically restart the engine so that the operator is aware of the need to turn off the ignition and can secure the vehicle before leaving. Otherwise, there is a possibility that the operator may leave the vehicle when the engine automatically stops (e.g., such as if, due to a malfunction, the engine cannot restart when the brake pedal is released in a vehicle equipped with an automatic transmission), and then the engine restarts when the driver leaves, resulting in unexpected vehicle movement.

[0059] In one example, if it is determined that the operator has not tightened the seatbelt for more than a threshold percentage of total driving cycles, loosening the seatbelt may not be considered a condition for restarting the engine. Figure 3 Further engine restart conditions are discussed in step 316 of method 300, and will not be repeated here. If it is determined that the engine restart conditions are not met, at 409, the engine may remain off and combustion may not be resumed until the engine restart conditions are met.

[0060] If the engine restart conditions are determined to be met, at step 412, the procedure includes determining whether the vehicle is equipped with an automatic transmission system. In an automatic transmission system, there is no clutch pedal in the driver's cab, and the gear ratios can be automatically adjusted based on engine speed and torque demands during vehicle operation. If it is determined that the vehicle is equipped with an automatic transmission system, the procedure can proceed to step 420, and the engine can be restarted by refueling and re-ignition.

[0061] If it is determined that the vehicle is not equipped with an automatic transmission system, then at point 414, it can be inferred that the vehicle is equipped with a manual transmission system. At point 416, the procedure includes determining whether the clutch pedal is engaged. If the engine is restarted due to increased engine power demand from auxiliary systems (such as the air conditioning being turned on) rather than due to increased torque demand, the operator may not engage the clutch pedal. If the clutch pedal is not engaged, engine torque cannot be transmitted to the wheels.

[0062] If it is determined that the clutch pedal is not engaged, at point 418, the operator can be notified via a message on the HMI to depress the clutch pedal. By engaging the clutch pedal, engine torque can be transmitted to the transmission system and wheels. In one example, the operator can be notified via the HMI to depress any pedal (such as the clutch, brake, or accelerator) to confirm the operator's presence in the vehicle should the engine restart occur. If, due to a malfunction in the seatbelt sensor, it is impossible to detect whether the operator has unbuckled their seatbelt and left the vehicle, a secondary confirmation via pedal engagement may be necessary before restarting the engine. In this way, it is confirmed that the engine may not restart in the absence of the operator.

[0063] If the clutch engagement is confirmed, the engine is restarted at 420°. The controller can send signals to the fuel injectors and spark plugs to restore fuel and spark for restarting combustion.

[0064] In this manner, during vehicle operations with the doors detached from the vehicle body, the procedure includes activating engine idle-stop in response to the vehicle being stationary and the seatbelts attached to the vehicle operator's seat being secured, and disabling engine idle-stop in response to the seatbelts being released. Activating idle-stop may include suspending engine combustion by inhibiting fuel injection and sparking to one or more engine cylinders, and disabling idle-stop may include maintaining engine combustion.

[0065] Figure 5 An exemplary operation sequence 500 is shown, illustrating an implementation of an engine start / stop function in a vehicle with a removable driver's door. The horizontal line (x-axis) represents time, while the vertical markers t1 to t7 represent significant moments in the operation of the vehicle with the removable driver's door.

[0066] The first curve 502 shows the location of the mechanical brake pedal housed in the driver's cab. The second curve 504 shows the vehicle speed over time, estimated via wheel speed sensors. The dashed line 505 represents a threshold speed below which the engine may shut off. The third curve 506 shows the attachment status of the driver's side door, estimated via a shunt connector switch and a window motor connected to the driver's door. The door can be attached to the body (closed) or detached from the body (disconnected). The fourth curve shows the attachment status of the seatbelt connected to the driver's seat via a seatbelt sensor. The fifth curve 510 shows the operation of the air conditioning system. The sixth curve 512 shows engine operation, particularly when the engine is ignited (closed) or deactivated (disconnected). The seventh curve 514 shows the location of the clutch pedal housed in the driver's cab in vehicles equipped with a manual transmission system.

[0067] Before time t1, the brake pedal is fully disengaged, the clutch pedal is engaged, and the vehicle is operating at a speed exceeding the threshold speed of 505. Engine cylinder combustion is performed to generate power for propelling the vehicle. The vehicle is operated with the driver's door removed (disconnected). The operator is in the driver's seat with the seatbelt fastened (closed). At this time, the air conditioning system is not in use (is off).

[0068] At time t1, the operator depresses the brake pedal and the clutch pedal disengages. In response to the change in brake pedal position, the vehicle speed decreases between times t1 and t2. At time t2, the vehicle speed has decreased to a threshold speed of 505. In response to the vehicle speed decreasing to the threshold speed, at time t2, the idle-stop condition is confirmed. Upon confirming that the seatbelts are secured, engine idle-stop is initiated to improve fuel efficiency and emissions quality, and engine combustion is suspended. To initiate idle-stop, refueling (to the cylinders) is prohibited, and spark plugs are disabled. Between times t2 and t3, the vehicle speed remains below the threshold speed of 505, and engine rotation decelerates to a standstill, for example, the engine coasts to a stop.

[0069] At time t3, the air conditioning system is turned on, thus requesting energy from the engine. To provide energy to the air conditioning system, it is desirable to restart the engine and resume combustion, even when the vehicle is stationary. However, the clutch is not engaged at this time, thus preventing the engine from restarting from idle to stop. The operator is notified to engage the clutch pedal via a human-machine interface (HMI) connected to the vehicle's instrument panel. In response to this notification, at time t4, the clutch pedal is engaged and the controller restarts the engine by resuming fuel and spark. Between times t4 and t5, the engine is operated to provide energy for operating the air conditioning system while the vehicle remains stationary.

[0070] At time t5, the brake pedal is released and the vehicle is propelled by engine torque. Between times t5 and t6, the vehicle speed gradually increases and the engine is operating to meet torque demands. The air conditioning system is turned off, thereby reducing parasitic use of engine power. At time t6, the operator depresses the brake pedal. In response to the change in brake pedal position, between times t6 and t7, the vehicle speed decreases, and at time t7, the vehicle speed decreases to a threshold speed of 505. In response to the vehicle speed decreasing to the threshold speed, at time t7, it is deduced that the idle-stop condition is met. However, at time t7, the driver's seatbelt is released, indicating that the operator may leave the vehicle once it stops. Even if the vehicle comes to a complete stop (after time t7), in response to the seatbelt being released, engine operation does not change and combustion continues.

[0071] In this way, by adjusting the engine start / stop function of vehicles equipped with removable doors, engine idle-stop can be performed even when the driver's door is removed. The technical effect of detecting the driver's presence by determining the driver's seatbelt status is that idle-stop or engine restart can be delayed until the driver is present in the vehicle. By eliminating the possibility of engine restart and vehicle propulsion in the absence of a driver, the driving experience can be improved. In conclusion, by continuing to perform the engine start / stop function when the driver's door is in the removed position, fuel efficiency and emissions quality can be improved.

[0072] An example method for a vehicle includes: detecting whether a driver's side door is attached or not; selecting a start / stop strategy for an engine propelling the vehicle based on the driver's side door attachment state; and further selecting the start / stop strategy based on the type of transmission connected between the engine and the vehicle. In any of the foregoing examples, additionally or optionally, the door attachment state is estimated based on the position of a switch in a connector shunt connected to the door, the closed position of the switch indicating the presence of the door, and the open position of the switch indicating the absence of the door. In any or all of the foregoing examples, additionally or optionally, the door attachment state is further based on the presence of a window motor connected to a window housed in the door, the presence of the door being confirmed based on the presence of the window motor. In any or all of the foregoing examples, additionally or optionally, the presence of the window motor is detected by transmitting current via the window motor. In any or all of the foregoing examples, additionally or optionally, the type of transmission connecting the engine and the vehicle is an automatic transmission system, and selecting the start / stop strategy based on the transmission type includes causing the engine connected to the vehicle to idle-stop when the automatic transmission system is in drive and the operator depresses the brake pedal. In any or all of the foregoing examples, additionally or optionally, the type of transmission connecting the engine and the vehicle is a manual transmission system, and selecting the start / stop strategy based on the transmission type includes causing the engine connected to the vehicle to idle-stop when the manual transmission system is in neutral and the operator releases the clutch pedal. In any or all of the foregoing examples, additionally or optionally, selecting the engine start / stop strategy based on the driver's side door attachment status includes selecting a first strategy in response to the presence of the door, and selecting a second strategy in response to the absence of the door, wherein the first strategy includes causing the engine to idle-stop when the door is locked, and wherein the second strategy includes causing the engine to idle-stop regardless of the door lock status. In any or all of the foregoing examples, additionally or optionally, the second strategy further includes each of the following: suspending engine combustion in response to each of the engine idling time exceeding a threshold duration and the seat belt connected to the seat occupied by the operator during driving the vehicle being in a tightened state; and continuing engine combustion in response to each of the engine idling time exceeding the threshold duration and the seat belt being in a loose state.In any or all of the foregoing examples, additionally or optionally, the second strategy further includes restarting engine combustion in response to one or more of the following: the automatic transmission system shifts from drive, the seatbelt is unfastened, the brake pedal is released in the vehicle equipped with the automatic transmission system, and the clutch pedal is engaged in the vehicle equipped with the manual transmission system. In any or all of the foregoing examples, additionally or optionally, the second strategy further includes, during engine combustion suspension, in response to an increase in engine power demand in the vehicle equipped with the manual transmission system and with the clutch pedal unfastened, instructing the operator to engage the clutch pedal and maintain engine combustion suspension until the clutch pedal is engaged. In any or all of the foregoing examples, additionally or optionally, the method further includes instructing the operator via a human-machine interface (HMI) coupled to the vehicle dashboard to disable engine idle-stop in response to each of the absence of the driver's side door and the seatbelt being unfastened.

[0073] Another exemplary method includes: during the operation of removing the door from the vehicle body, activating an engine idle-stop coupled to the vehicle in response to the vehicle being stationary and the seatbelt coupled to the vehicle operator's seat being fastened, and disabling the engine idle-stop in response to the seatbelt being unfastened. In any of the foregoing examples, additionally or alternatively, activating the idle-stop includes suspending engine combustion by inhibiting fuel injection and sparking to one or more engine cylinders, and disabling the idle-stop includes maintaining engine combustion. In any or all of the foregoing examples, additionally or alternatively, the vehicle is equipped with an automatic transmission system, and during the idle-stop, the transmission is in drive and the brake pedal is engaged. In any or all of the foregoing examples, additionally or alternatively, the vehicle is equipped with a manual transmission system, and during the idle-stop, the manual transmission system is in neutral and the clutch pedal is released. In any or all of the foregoing examples, additionally or optionally, the method further includes detecting the removal of the door from the vehicle body based on the open position of a switch housed in a connector shunt coupled to the door and the absence of current flowing through each of a motor coupled to a window housed in the door, and detecting the attachment status of the seatbelt based on input from a seatbelt sensor coupled to the buckle of the seatbelt. In any or all of the foregoing examples, additionally or optionally, the door is attached to the driver's cab next to the vehicle operator's seat when attached to the vehicle body.

[0074] In yet another example, a vehicle system includes: a controller having computer-readable instructions stored in a non-transitory memory to perform the following operations: estimating the attachment state of a door based on the position of a switch coupled to a door connector shunt and the presence or absence of current flowing through a motor coupled to a window housed in a door of the vehicle; and, in response to the absence of the door in the vehicle body and the vehicle remaining stationary for more than a threshold duration, estimating the attachment state of a seatbelt via a seatbelt buckle sensor, and selectively initiating an engine idle-stop based on the attachment state of the seatbelt and the type of transmission system coupled to the vehicle. In any of the foregoing examples, additionally or alternatively, the door is coupled to the vehicle body next to a seat occupied by a vehicle operator in the vehicle's passenger compartment, and wherein the seatbelt is coupled to the seat and secured to the seat via the buckle. In any or all of the foregoing examples, additionally or optionally, the transmission system is a manual transmission system, and wherein selectively initiating engine idle-stop includes suspending combustion in one or more engine cylinders in response to each of the seatbelt being fastened, the transmission system being in neutral, and the clutch pedal connected to the passenger compartment being released. In any or all of the foregoing examples, additionally or optionally, the transmission system is an automatic transmission system, and wherein selectively initiating engine idle-stop includes suspending combustion in the one or more engine cylinders in response to each of the seatbelt being fastened, the transmission system being in drive, and the brake pedal connected to the passenger compartment being engaged.

[0075] Note that the exemplary control and estimation programs included herein can be used in conjunction with various engine and / or vehicle system configurations. The control methods and programs disclosed herein can be stored as executable instructions in non-transitory memory and can be executed by a control system including a controller in conjunction with various sensors, actuators, and other engine hardware. The specific programs described herein can represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multi-tasking, multi-threaded processing strategies, etc. Therefore, the various actions, operations, or functions shown may be executed sequentially, in parallel, or in some cases omitted. Similarly, the processing order is not necessarily required to achieve the features and advantages of the exemplary embodiments described herein, but is provided for ease of illustration and description. One or more of the actions, operations, and / or functions shown may be repeatedly executed depending on the specific strategy used. Furthermore, the actions, operations, and / or functions can be graphically represented as code programmed into a non-transitory memory of a computer-readable storage medium in an engine control system, wherein the actions are performed by executing instructions in a system including various engine hardware components in conjunction with an electronic controller.

[0076] It should be understood that the configurations and procedures disclosed herein are exemplary in nature, and these specific embodiments should not be considered limiting, as many variations are possible. For example, the above-described techniques can be applied to V-6, I-4, I-6, V-12, opposed 4-cylinder, and other engine types. The subject matter of this disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations disclosed herein, as well as other features, functions, and / or properties.

[0077] The following claims specifically point to certain combinations and sub-combinations considered novel and non-obvious. These claims may relate to an “a” element or a “first” element or its equivalent. These claims should be understood to include the introduction of one or more such elements, thus neither requiring nor excluding two or more such elements. Other combinations and sub-combinations of the disclosed features, functions, elements, and / or properties may be claimed by amendment to these claims or by setting new claims in this application or related applications. Such claims, whether broader, narrower, equivalent, or different in scope from the original claims, are considered to be included within the subject matter of this disclosure.

[0078] According to the present invention, a method for a vehicle includes: detecting whether a driver's side door is attached or not (attached state); selecting a start / stop strategy for an engine that propels the vehicle based on the driver's side door attachment state; and further selecting the start / stop strategy based on the type of transmission connected between the engine and the vehicle.

[0079] According to one embodiment, the attachment state of the vehicle door is estimated based on the position of a switch in a connector shunt connected to the door, wherein a closed position of the switch indicates that the door is present, and an open position of the switch indicates that the door is not present.

[0080] According to one embodiment, the door attachment state is further based on the presence of a window motor connected to a window housed in the door, the presence of the door being confirmed based on the presence of the window motor.

[0081] According to one embodiment, the presence of the window motor is detected by transmitting current via the window motor.

[0082] According to one embodiment, the type of transmission connected between the engine and the vehicle is an automatic transmission system, and selecting the start / stop strategy based on the transmission type includes causing the engine to idle-stop when the automatic transmission system is in drive gear and the operator depresses the brake pedal.

[0083] According to one embodiment, the type of transmission connected between the engine and the vehicle is a manual transmission system, and selecting the start / stop strategy based on the transmission type includes idling-stopping the engine when the manual transmission system is in neutral and the operator releases the clutch pedal.

[0084] According to one embodiment, selecting the engine start / stop strategy based on the driver's side door attachment state includes selecting a first strategy in response to the presence of the door and selecting a second strategy in response to the absence of the door, wherein the first strategy includes idling-stopping the engine when the door is locked, and wherein the second strategy includes idling-stopping the engine regardless of the door lock status.

[0085] According to one embodiment, the second strategy further includes each of the following: suspending engine combustion in response to each of the engine idling time exceeding a threshold duration and the seat belt connected to the seat occupied by the operator during driving the vehicle being in a tightened state; and continuing engine combustion in response to each of the engine idling time exceeding the threshold duration and the seat belt being in a loose state.

[0086] According to one embodiment, the second strategy further includes restarting engine combustion in response to one or more of the following: the automatic transmission system shifting from driving gear, the seat belt being released, the brake pedal being released in the vehicle equipped with the automatic transmission system, and the clutch pedal being engaged in the vehicle equipped with the manual transmission system.

[0087] According to one embodiment, the second strategy further includes, during engine combustion pause, in response to an increase in engine power demand in the vehicle equipped with the manual transmission system and with the clutch pedal disengaged, instructing the operator to engage the clutch pedal and maintain engine combustion pause until the clutch pedal is engaged.

[0088] According to one embodiment, the invention is further characterized in that the operator is instructed via a human-machine interface (HMI) connected to the vehicle dashboard to disable engine idle-stop in response to either the absence of the driver's side door or the unfastened seat belt.

[0089] According to the present invention, a method includes, during operation of the vehicle in which the door is detached from the vehicle body, activating an engine idle-stop coupled to the vehicle in response to the vehicle being stationary and the seat belt coupled to the seat of the vehicle operator being fastened, and disabling the engine idle-stop in response to the seat belt being unfastened.

[0090] According to one embodiment, enabling idle-stop includes suspending engine combustion by prohibiting fuel injection and sparking to one or more engine cylinders, and disabling idle-stop includes maintaining engine combustion.

[0091] According to one embodiment, the vehicle is equipped with an automatic transmission system, and during the idle-stop period, the transmission is in driving gear and the brake pedal is engaged.

[0092] According to one embodiment, the vehicle is equipped with a manual transmission system, and during the idle-stop period, the manual transmission system is in neutral and the clutch pedal is released.

[0093] According to one embodiment, the invention is further characterized in that the removal of the vehicle door from the vehicle body is detected based on the open position of a switch housed in a connector shunt connected to the vehicle door and the absence of current flowing through a motor connected to a window housed in the vehicle door; and the attachment state of the seat belt is detected based on input from a seat belt sensor with a buckle connected to the seat belt, wherein the vehicle door is attached to the cab next to the seat of the vehicle operator when attached to the vehicle body.

[0094] According to the present invention, a vehicle system is provided, the vehicle system comprising: a controller having computer-readable instructions stored in a non-transitory memory to perform the following operations: estimating the attachment state of a door based on the position of a switch coupled to a door connector shunt and the presence or absence of current passing through a motor coupled to a window housed in a door of the vehicle; and, in response to the absence of the door in the vehicle body and the vehicle being stationary for a duration exceeding a threshold, estimating the attachment state of a seatbelt via a seatbelt sensor coupled to a buckle of a seatbelt, and selectively initiating an engine idle-stop based on the attachment state of the seatbelt and the type of transmission system coupled to the vehicle.

[0095] According to one embodiment, the door is connected to the vehicle body next to a seat occupied by the vehicle operator in the vehicle compartment, and wherein the seat belt is connected to the seat and fastened to the seat via the buckle.

[0096] According to one embodiment, the transmission system is a manual transmission system, and selectively initiating engine idle-stop includes suspending combustion in one or more engine cylinders in response to each of the seat belt being fastened, the transmission system being in neutral, and the clutch pedal coupled to the passenger compartment being released.

[0097] According to one embodiment, the transmission system is an automatic transmission system, and selectively initiating engine idle-stop includes suspending combustion in one or more engine cylinders in response to each of the seat belt being fastened, the transmission system being in drive, and the brake pedal coupled to the passenger compartment being engaged.

Claims

1. A method for a vehicle, comprising: Detect whether the driver's side door is attached or not, i.e., the driver's side door attachment status; Selecting a start / stop strategy for the engine that propels the vehicle based on the driver's side door attachment state includes selecting a first strategy based on a door lock state in response to the attachment of the door, and selecting a different second strategy independently of the door lock state in response to the absence of the door and therefore the door being removed from the vehicle body. as well as The start / stop strategy is further selected based on the type of transmission connected between the engine and the vehicle.

2. The method of claim 1, wherein the door attachment state is estimated based on the position of a switch in a connector shunt connected to the door, the closed position of the switch indicating that the door is attached, and the open position of the switch indicating that the door is not attached.

3. The method of claim 1, wherein the door attachment state is further based on the presence of a window motor connected to a window housed in the door, the attachment of the door being confirmed based on the presence of the window motor.

4. The method of claim 3, wherein the presence of the window motor is detected by transmitting current via the window motor.

5. The method of claim 1, wherein the type of transmission connected between the engine and the vehicle is an automatic transmission system, and selecting the start / stop strategy based on the transmission type includes idling-stopping the engine when the automatic transmission system is in drive gear and the operator depresses the brake pedal.

6. The method of claim 5, wherein the type of transmission connected between the engine and the vehicle is a manual transmission system, and selecting the start / stop strategy based on the transmission type includes idling-stopping the engine when the manual transmission system is in neutral and the operator releases the clutch pedal.

7. The method of claim 6, wherein the first strategy includes stopping the engine from idling when the door is locked, and wherein the second strategy includes stopping the engine from idling regardless of the door being locked.

8. The method of claim 7, wherein the second strategy further comprises each of the following: suspending engine combustion in response to each of the engine idling time exceeding a threshold duration and the seat belt connected to a seat occupied by the operator during driving the vehicle being in a secured state; and continuing engine combustion in response to each of the engine idling time exceeding the threshold duration and the seat belt being in a released state.

9. The method of claim 7, wherein the second strategy further comprises restarting engine combustion in response to one or more of the following: the automatic transmission system shifting from driving gear, the seatbelt being released, the brake pedal being released in the vehicle equipped with the automatic transmission system, and the clutch pedal being engaged in the vehicle equipped with the manual transmission system.

10. The method of claim 7, wherein the second strategy further comprises, during engine combustion pause, in response to an increase in engine power demand in the vehicle equipped with the manual transmission system and the clutch pedal not engaged, instructing the operator to engage the clutch pedal and maintain engine combustion pause until the clutch pedal is engaged.

11. The method of claim 8, further comprising instructing the operator via a human-machine interface (HMI) coupled to the vehicle dashboard to disable engine idle-stop in response to each of the absence of the door and the unfastened seatbelt.

12. A vehicle system comprising: A controller having computer-readable instructions stored in non-transitory memory to perform the following operations: The attachment state of the vehicle door is estimated based on the position of the switch connected to the shunt of the door connector and the presence or absence of current flowing through the motor connected to the window housed in the vehicle door. and In response to the absence of the door in the vehicle body and the removal of the door from the vehicle body and the vehicle remaining stationary for a duration exceeding a threshold, the attachment state of the seat belt is estimated via a seat belt sensor with a buckle connected to the seat belt, and the engine idle-stop is selectively initiated based on the attachment state of the seat belt and the type of transmission system connected to the vehicle.

13. The system of claim 12, wherein the door is coupled to the body of the vehicle next to a seat occupied by a vehicle operator in the passenger compartment, and wherein the seat belt is coupled to the seat and fastened to the seat via the buckle.

14. The system of claim 13, wherein the transmission system is a manual transmission system, and wherein selectively initiating engine idle-stop includes suspending combustion in one or more engine cylinders in response to each of the seatbelt being fastened, the transmission system being in neutral, and the clutch pedal coupled to the passenger compartment being released.

15. The system of claim 13, wherein the transmission system is an automatic transmission system, and wherein selectively initiating engine idle-stop includes suspending combustion in one or more engine cylinders in response to each of the seatbelt being fastened, the automatic transmission system being in drive, and the brake pedal coupled to the passenger compartment being engaged.

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