Apparatuses, methods, and systems including hybrid powertrain with fit clutch

Abstract

A vehicle includes a hybrid powertrain and a fit clutch. The hybrid powertrain includes an engine and a motor / generator that are controlled such that a fit clutch is effectively used in the hybrid powertrain during transitions between vehicle start-up, shift, engine start-up, and propulsion modes.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims priority to and the benefit of U.S. Provisional Application Serial No. 63 / 373,372, filed on August 24, 2022, which is incorporated herein by reference. Technical Field

[0003] The present disclosure relates to apparatus, methods, and systems including a hybrid powertrain system having a mesh clutch. Background Art

[0004] Friction-type clutches are widely used to connect internal combustion engines to drivetrains, such as during engine starting and gear shifting. This is because the friction-type clutch allows controlled slip between the output shaft of the engine and the drivetrain. Thus, when the engine speed is synchronized with the drivetrain speed, the friction-type clutch can be used to smoothly complete the start of the vehicle from a stop or after a gear shift by controlling the allowed slip between the engine and the drivetrain. However, friction-type clutches are complex, expensive, and take up a large amount of space in the powertrain architecture. Therefore, there is still a significant unmet need for the unique apparatus, methods, and systems disclosed herein.

[0005] Disclosure of Exemplary Embodiments

[0006] In order to clearly, concisely and accurately describe the exemplary embodiments of the present disclosure, the manner and process of making and using the present disclosure, and to enable the practice, manufacture and use of the present disclosure, reference will now be made to certain exemplary embodiments, including those shown in the figures, and specific language will be used to describe the present disclosure. However, it should be understood that no limitation of the scope of the present invention is thereby created, and the present invention includes and protects such changes, modifications and further applications of the exemplary embodiments that would occur to those skilled in the art. Summary of the invention

[0007] Exemplary embodiments include unique apparatus, methods, and systems that include a hybrid powertrain having a dog-type clutch for engaging an output shaft of an internal combustion engine to an input shaft of a driveline. In one embodiment, the hybrid powertrain and the dog-type clutch are controlled to start the engine. In one embodiment, the hybrid powertrain and the dog-type clutch are controlled to shift a transmission. In one embodiment, the hybrid powertrain and the dog-type clutch are controlled for starting a vehicle. In one embodiment, the hybrid powertrain and the dog-type clutch are controlled to switch between propulsion modes of the hybrid powertrain. Further embodiments, forms, objects, features, advantages, aspects, and benefits will become apparent from the following description and accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a schematic diagram illustrating certain aspects of an exemplary vehicle including a powertrain with a dog-type clutch.

[0009] Figure 2 It is shown for Figure 1 A flow chart of certain aspects of an exemplary control method for vehicle launch of a vehicle.

[0010] Figure 3 It is shown for Figure 1 A flow chart of certain aspects of another exemplary control method for vehicle launch of a vehicle.

[0011] Figure 4 It is shown for Figure 1 A flow chart of certain aspects of another exemplary control method for vehicle launch of a vehicle.

[0012] Figure 5 It is shown for Figure 1 A flow chart of certain aspects of another exemplary control method for shifting gears of a vehicle.

[0013] Figure 6 It is shown for Figure 1 A flow chart of certain aspects of another exemplary control method for transitioning between propulsion modes of a vehicle.

[0014] Figure 7 It is shown for Figure 1 A flow chart of certain aspects of another exemplary control method for transitioning between propulsion modes of a vehicle.

[0015] Figure 8 is shown for starting Figure 1 A flow chart of certain aspects of another exemplary control method of an engine of a stationary vehicle.

[0016] Fig. 9 is shown for starting Figure 1 A flow chart of certain aspects of another exemplary control method of an engine of a stationary vehicle. DETAILED DESCRIPTION

[0017] refer to Figure 1 , an exemplary vehicle 20 is shown. In the illustrated embodiment, the vehicle 20 includes a drivetrain 22, which includes an internal combustion engine 32, an output shaft 33, a clutch 34, a motor / generator (M / G) 25, and a transmission 27. The transmission 27 may include a transmission 26, a differential 28, and a ground-engaging wheel 29. In the illustrated embodiment, the vehicle 20 is driven by the ground-engaging wheel 29, which is configured and arranged as a rear wheel. In other embodiments, front-wheel drive, four-wheel drive, and all-wheel drive methods can be envisioned. In various embodiments, the vehicle 20 can be configured and arranged as a highway bus, a delivery truck, a service truck, a passenger truck, a passenger car, etc. In other aspects, the vehicle 20 can be configured and arranged as different types of vehicles, including other types of highway vehicles or off-road vehicles.

[0018] In the illustrated embodiment, the powertrain 22 includes an internal combustion engine 32, which is operably coupled to an output shaft 33 and is configured to provide torque to the output shaft. In some embodiments, the output shaft 33 can be configured and arranged as a flywheel and / or a crankshaft. A first side of a dog clutch 34 is operably connected to the output shaft 33 and then to the engine 32 and is configured to provide torque thereto (or receive torque therefrom). A second side of the dog clutch 34 is operably coupled to the motor / generator 25 and then to the input shaft 24 of the transmission 26 and then to other components of the powertrain 22 that can be coupled thereto and is configured to provide torque thereto (or receive torque therefrom).

[0019] The dog clutch 34 can be electronically controlled between a closed state and a disconnected state. In the closed state, torque applied to the first side of the dog clutch 34 is transferred to the second side of the dog clutch 34, and vice versa. In the disconnected state, torque is not transferred between the first side and the second side of the dog clutch 34, for example, due to the presence of clearance or separation between the clutch components. As used herein, the dog clutch 34 is a non-slip clutch, wherein the first side and the second side of the clutch are configured to interlock with each other in a closed position, and there is no slip between the first side and the second side. Examples of dog clutches include dog clutches, spline clutches, jaw clutches, dog clutches, etc.

[0020] The motor / generator 25 is configured and arranged in the form of a traction motor, which is separate and different from the optional starter motor 39, which is coupled to the engine 32 and is dedicated to the starting engine under certain conditions. In some embodiments, the starter motor 39 can be omitted from the vehicle 20. The motor / generator 25 can be operated as a motor to output torque to the input shaft 24 of the transmission 26 to propel the vehicle. This operation can occur when the dog clutch 34 is disconnected, so that only the motor / generator 25 is used to propel the vehicle. This operation can also occur when the dog clutch 34 is closed, so that the motor / generator 25 is combined with the engine 32 to propel the engine, or the engine 32 propels the vehicle 20 through the motor / generator 25 while generating electrical energy using the motor / generator 25. The motor / generator 25 can also be operated as a generator to receive torque from the input shaft 24 of the transmission 26, such as during regenerative braking operation. The motor / generator 25 can also be operated as a motor to drive the engine 32 via the dog clutch 34, such as during engine restart operation.

[0021] In the illustrated embodiment, the powertrain 22 is configured and arranged as a parallel hybrid combustion engine-electric powertrain. In other embodiments, the powertrain 22 may take other forms of hybrid combustion engine-electric powertrains. In the illustrated embodiment, the powertrain 22 is configured and arranged in which a dog-type clutch 34 is coupled to and located between the engine 32 and the motor / generator 25. In other embodiments, the dog-type clutch 34 may be coupled to and located between the engine 32 and the motor / generator 25, and another clutch may be coupled to and located between the motor / generator 25 and the input shaft 24 of the transmission 26.

[0022] The transmission 26 can be configured and arranged in a variety of forms. In some forms, the transmission 26 can be configured and arranged as a manual transmission, including a gearbox and an internal clutch actuated by an operator. In some forms, the transmission 26 can be configured and arranged as an automated manual transmission, including a gearbox and an internal clutch, which can be actuated automatically or in response to an operator's input. In some forms, the transmission 26 can be configured and arranged as an automatic transmission including a planetary gear set. In some forms, the transmission 26 can be configured and arranged as a continuously variable transmission.

[0023] In the illustrated embodiment, the engine 32 is configured as a turbocharged, compression-ignition diesel engine, including a cylinder decompression system 71. It should be understood that in other embodiments, the engine 32 can be configured as another type of engine. The powertrain 22 can be provided with a turbocharger 31, which includes a turbine 37 and a compressor 38. The turbine 37 extracts energy from the exhaust of the engine 32 to drive the compressor 38 to compress the boost air flow flowing to the engine 32. In other embodiments, the powertrain 22 can be provided with torque by additional components (such as a motor operably coupled to a battery or other energy storage system, one or more vehicle accessories, or other power supply components).

[0024] The cylinder decompression system 71 can be provided in a variety of forms that are configured and operable to reduce cylinder pressure during the compression stroke of the engine 32 (relative to the cylinder pressure that would otherwise be generated by the compression stroke). In some forms, the cylinder decompression system 71 can be configured and arranged as a cylinder deactivation (CDA) system. In some forms, the cylinder decompression system 71 can be configured and arranged as a compression release braking system. In some such forms, a hydraulic or electric actuator can be arranged in the valve train between the valve of the engine 32 and the valve cam of the engine 32, and can be electronically controlled to change the response of the valve to the valve cam. For example, such an actuator can be provided to selectively keep the exhaust valve and / or intake valve open and / or closed during at least a portion of the piston stroke of the engine 32.

[0025] In the illustrated embodiment, the vehicle 20 may include an exhaust aftertreatment system 60 disposed downstream of the engine 32 that injects liquid reductant into the exhaust flow of the diesel engine through a special catalyst. The exhaust aftertreatment system 60 may include a selective catalytic reduction (SCR) catalyst 61 that is configured to inject liquid reductant into the exhaust flow.

[0026] The vehicle 20 includes an electronic control system (ECS) 40, which includes a plurality of control components and structures. The ECS 40 may include one or more programmable microprocessors or microcontrollers of the solid-state integrated circuit type, which are disposed in one or more component control units of the ECS 40. It is also conceivable that the ECS 40 may include other types of integrated circuits and / or discrete circuit control units. In the illustrated embodiment, the ECS 40 includes an engine control unit (ECU) 42, a transmission control unit (TCU) 44, and may include one or more additional control units (XCU) 46. The ECU 42, TCU 44, and XCU 46 (if present) are operably connected via a network 41 and are configured to communicate via the network, which may be configured as a controller area network (CAN) or other types of networks that provide communication capabilities. The ECS 40 is also operably connected to various components and systems of the vehicle system 20 via the network 41 or one or more additional or alternative networks.

[0027] The ECS 40 may be implemented in a variety of configurations that combine or distribute control components, functions or processes in various ways over one or more control units. The ECS 40 executes operational logic that defines various control, management and / or regulation functions. The operational logic may be in the form of dedicated hardware (such as a hardwired state machine), an analog computing machine, programming instructions, and / or in different forms as will occur to one skilled in the art. The ECS 40 may be provided as a single component or a collection of operably connected components; and may include digital circuits, analog circuits, or a hybrid combination of these two types. When in a multi-component form, the ECS 40 may have one or more components that are remotely located relative to other components in a distributed arrangement. The ECS 40 may include multiple processing units that are arranged to operate independently in a pipeline processing arrangement, a parallel processing arrangement, or the like. It should also be understood that the ECS 40 and / or any of its component parts 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, clamping circuits, delay devices, memory devices, analog-to-digital (A / D) converters, digital-to-analog (D / A) converters, and / or different circuits or components for performing the desired communications as will occur to those skilled in the art.

[0028] refer to Figures 2 to 5, shows an exemplary method that may be implemented and performed by operating an electronic control system (such as ECS 40) or another electronic control system operably coupled to a vehicle system (e.g., vehicle 20 or another vehicle system) including an engine (e.g., engine 32 or another engine). When implemented and performed by ECS 40, the method may be performed in whole or in part by ECU 42, TCU 44, XCU 46, other components of ECS 40, or a combination of these components.

[0029] For example, in Figure 2 , method 200 begins at operation 202 to receive a command or input to start vehicle 20, such as a vehicle start from a stopped position. Operation 202 may take into account, for example, a key on / off state of vehicle 20, an on / off operating state of engine 32, an accelerator pedal position, a brake pedal position, or other indicators of vehicle start during vehicle operation. From start operation 202, method 200 proceeds to condition 204 to evaluate whether the dog clutch 34 is disengaged. If condition 204 is evaluated negatively, method 200 continues at operation 206 to disengage the dog clutch 34. If condition 204 is positive, or after completing operation 206, method 200 continues at operation 208 to propel vehicle 20 using only power from motor / generator 25 for start, while motor / generator 25 is disengaged from engine 32.

[0030] After operation 208, if the engine 32 has not been started, the engine 32 can be started at operation 210. For example, when the clutch 34 is disconnected, the starter motor 39 can be used to start the rotation of the engine 32, thereby starting. The method 200 continues at operation 212 to control the speed of the started engine 32 and the transmission 27 to obtain a synchronous speed. For example, the speed of the output shaft 33 can be synchronized within a predetermined threshold of the speed of the input shaft 24 and / or the speed of the motor / generator 25. In one embodiment, the ECS 40 controls the speed of the engine 32 and the motor / generator 25 so that the speeds are synchronized within a threshold allowed by each other.

[0031] After the synchronous speeds of the engine 32 and the driveline 27 are achieved or within an allowable threshold difference, the method 200 continues at operation 214 to close the dog clutch 34. Preferably, the allowable threshold difference in the speeds of the engine 32 and the driveline 27 required to close the dog clutch 34 provides acceptable smoothness during the transition while minimizing wear and damage to the dog clutch 34. Once the dog clutch 34 is closed, the engine 32 and / or the motor / generator 25 may be used to propel the vehicle 20, depending on the battery state of charge, torque demand, and / or other power distribution parameters between components of the driveline 22.

[0032] Operation 210 may include accelerating the engine 32 of the vehicle 20 toward a speed synchronized with the motor / generator 25 to engage the dog clutch 34. As used herein, the term "synchronous speed" refers to an engine speed at or greater than the idle speed of the engine 32. It should be understood that the idle speed of the engine 32 may be different in various embodiments including different types of engines. For example, the idle speed of some engines may be 300 rpm or possibly lower. The idle speed of other engines may be 1200 rpm or possibly higher. The idle speed of some engines may be in the range of 500 rpm to 800 rpm. It should also be understood that the engine idle speed may vary dynamically during engine operation, for example, the engine idle speed may increase during engine warm-up operation and decrease after the engine is warmed up.

[0033] refer to Figure 3 Another embodiment method 300 for starting the vehicle 20 is discussed. The method 300 begins at operation 302 to receive a command or input to start the vehicle 20, such as a vehicle start from a stopped position. Operation 302 may take into account, for example, the key on / off state of the vehicle 20, the on / off operation state of the engine 32, the accelerator pedal position, the brake pedal position, or other indicators of vehicle start during vehicle operation. From the start operation 302, the method 300 proceeds to condition 304 to evaluate whether the dog clutch 34 is closed. If the evaluation result of condition 304 is negative, the method 300 continues at operation 306 to close the dog clutch 34.

[0034] If condition 304 is positive, or after completing operation 306, the method 300 continues at operation 308 to propel the vehicle 20 using only power from the motor / generator 25 to start, while the motor / generator 25 is engaged to the engine 32 using the dog clutch 34. Operation 308 also includes rotating the engine 32 using the motor / generator 25 due to the dog clutch 34 being closed. The method 300 continues at operation 310 to supply fuel to the rotating engine 32 to allow the engine 32 to start. For example, the motor / generator 25 can be used to accelerate the speed of the engine 32 until a threshold starting speed of the engine 32 is reached, at which time the supply of fuel is started. Once the engine 32 is started, the engine 32 and / or the motor / generator 25 can be used to propel the vehicle 20, depending on the state of charge of the battery, the torque demand, and / or other power distribution parameters between the powertrain components.

[0035] refer to Figure 4Another embodiment method 400 is discussed for starting the vehicle 20. The method 400 begins at operation 402 to receive a command or input to start the vehicle 20, such as a vehicle start from a stopped position. Operation 402 may take into account, for example, a key on / off state of the vehicle 20, an on / off operating state of the engine 32, an accelerator pedal position, a brake pedal position, or other indicators of vehicle start during vehicle operation.

[0036] From start operation 402, method 400 proceeds to conditional 404 where it is evaluated whether the dog clutch 34 is disengaged. If conditional 404 is evaluated negatively, method 400 continues at operation 406 to close the dog clutch 34. If conditional 404 is positive, or after completing operation 406, method 400 continues at operation 408 to activate cylinder decompression, such as by activating cylinder decompression system 71. This reduces the amount of electric torque required by motor / generator 25 to rotate engine 32.

[0037] The method 400 continues at operation 410 to propel the vehicle 20 using only power from the motor / generator 25 for starting while the motor / generator 25 is engaged to the engine 32 using the dog clutch 34. In addition, since the dog clutch 34 is closed, the engine 32 rotates with the motor / generator 25 at operation 410. Once the engine 32 begins to rotate, the cylinder decompression system 71 can be deactivated at operation 412. The method 400 continues at operation 414 to supply fuel to the engine 32 to allow the engine 32 to start. For example, the motor / generator 25 can be used to accelerate the speed of the engine 32 until a threshold starting speed of the engine 32 is reached and the cylinder decompression system 71 is deactivated, at which point fuel is started to be supplied to the engine 32. Once the engine 32 starts, the engine 32 and / or the motor / generator 25 can be used to propel the vehicle 20, depending on the state of charge of the battery, the torque demand, and / or other power distribution parameters between the powertrain components.

[0038] Operation 412 is based on or in response to the engine starting condition being evaluated as positive and in the case of deactivating the cylinder decompression system 71, the operation of the engine 32 is restored, and then the fuel supply of the engine 32 is restarted. In some embodiments, the action of deactivating the cylinder decompression system 71 is performed in response to the speed of the engine 32 reaching or exceeding the speed threshold corresponding to the engine starting speed. In some such embodiments, the speed threshold can be a fixed value or a predetermined value, which can be set to the engine starting speed or set relative to the starting speed, such as a threshold value that deviates from the engine starting speed or a value within the threshold value of the engine starting speed. In some such embodiments, the speed threshold can be determined dynamically. In some such embodiments, the speed threshold can be determined dynamically in response to the transmission input shaft speed (such as the speed of the transmission input shaft 24 or the input shaft of another transmission).

[0039] In some embodiments, the action of the deactivation cylinder decompression system 71 is performed in response to the state of vehicle clutch engagement. For example, in embodiments where the engine is accelerated toward a starting speed in whole or in part by closing the dog clutch 34, the closed position of the dog clutch 34 combined with the non-starting condition of the engine 32 can be used as the basis for deactivation cylinder decompression.

[0040] refer to Figure 5 , a method 500 for controlling a hybrid powertrain system 22 during a gear change of a transmission 26 by using a "clutchless" shift, wherein the meshing clutch 34 is not disengaged or actuated during the gear change, is discussed. The method 500 includes an operation 502 for propelling a vehicle 20 using the hybrid powertrain system 22. Depending on the power distribution parameters of the powertrain system 22, the vehicle 20 may be propelled by the engine 32, the motor / generator 25, or a combination of the engine 32 and the motor / generator 25.

[0041] The method 500 continues at operation 504 to unload the current transmission gear in response to a request to shift gears, such as from the driver or the ECS 40. In one embodiment, the engine 32 and the motor / generator 25 are gradually reduced to net zero torque to unload the current transmission gear at operation 504. The method 500 continues at operation 506 to shift the unloaded transmission 26 to neutral.

[0042] The method 500 continues at operation 508 to adjust the speeds of the engine 32 and the motor / generator 25 of the hybrid powertrain 22 for the new gear. For example, the engine torque and the motor / generator speed are controlled to accelerate or decelerate the engine 32 and the motor / generator 25 to the new speed required for the desired transmission gear.

[0043] Method 500 continues at operation 510 after operation 508 to shift the transmission from neutral to a new transmission gear. The output of the engine 32 and / or the motor / generator 25 may then be increased or decreased to meet the drive demand torque of the new gear. If additional gear changes are required, method 500 may be repeated as described above to shift the transmission 26 to the desired new gear.

[0044] Method 500 allows for a "clutchless" shift because the dog clutch 34 remains closed throughout the shift. The motor / generator 25 allows for very rapid application of negative or positive torque to unload the current gear and to accelerate or decelerate the engine 32 to shift into a new gear. In addition, fuel economy benefits can be achieved with a "clutchless" shift because energy losses due to clutch slip are eliminated. In addition, during an upshift, the inertia of the engine 32 can be recovered by operating the motor / generator 25 in generator mode.

[0045] refer to Figure 6 Another embodiment method 600 for starting the vehicle 20 is discussed. The method 600 involves converting the vehicle 20 from a first powertrain mode to a second powertrain mode. For example, the first powertrain mode may be an electric vehicle powertrain mode in which the motor / generator 25 provides the only propulsion, such as the engine 32 is stopped. The second powertrain mode may be a parallel hybrid powertrain mode in which the engine 32 provides some or all of the power to propel the vehicle 20.

[0046] When the vehicle 20 is operating in the first power transmission mode, the method 600 begins at operation 602. Operation 602 includes starting the engine 32 using the starter motor 39. The engine 32 may then be fueled to allow engine speed control. From the engine starting operation 602, the method 600 proceeds to operation 604, which synchronizes the speed of the engine 32 with the speed of the motor / generator 25. After speed synchronization, the routine 600 continues at operation 606 to close the clutch 34, thereby allowing the powertrain to operate in the parallel hybrid operating mode.

[0047] refer to Figure 7 , a variation of method 600 is provided with reference to method 700. Method 700 begins at operation 702 to control the torque output of the motor / generator 25 to zero to unload the transmission gear when the hybrid powertrain system is operating in the first powertrain mode. Method 700 continues at operation 704 to shift the transmission 26 to neutral after unloading the gear. After shifting to neutral, the speed of the motor / generator 25 is controlled to zero (0) speed at operation 706.

[0048] Once the speed of the motor / generator is zero, the dog clutch 34 is closed at operation 708. The motor / generator 25 can then be used to start and accelerate the engine 32 at operation 710. The speed of the motor / generator 25 and the speed of the engine 32 are controlled at operation 712 to accommodate the desired transmission gear, and the transmission 26 is shifted to the desired gear at operation 714.

[0049] Figure 8 Another embodiment method 800 is provided for starting the engine 32 when the vehicle 20 is stationary. For example, the method 800 may be employed when operation of the engine 32 is needed to power accessories or to charge the battery of the vehicle 20. The method 800 begins at operation 802. Operation 802 includes shifting the transmission 26 into neutral and / or applying the parking brake (if necessary). The routine 800 continues at operation 804 to disengage the clutch 34 while the transmission 26 is in neutral and the parking brake is applied.

[0050] At operation 806, the engine 32 is started using the starter motor 39. At operation 808, the engine is fueled and the speed of the engine 32 is then synchronized with the speed of the motor / generator 25. Once the speeds are synchronized, the clutch 34 is closed at operation 810. The engine 32 can then be used to power accessories and / or charge the battery of the vehicle 20.

[0051] Fig. 9 A variation of method 800 is provided with reference to method 900. Method 900 begins at operation 902. Operation 902 includes shifting the transmission 26 into neutral and / or applying the parking brake (if necessary). Routine 900 continues at operation 904 to close the clutch 34 while the transmission is in neutral and the parking brake is applied.

[0052] After closing the clutch 34, the method 900 continues at operation 906. The engine 32 may then be started at operation 906 using the starter motor 39 (if provided) or the motor / generator 25. Starting the engine 32 may include supplying fuel to the engine 32 so that accessories may be operated and / or the battery may be charged.

[0053] As shown in the foregoing description, the present disclosure contemplates multiple aspects and embodiments including the following examples. It is contemplated that one or more aspects and / or embodiments may be combined with one or more other aspects and / or embodiments.

[0054] A first aspect of the present disclosure relates to a method for starting a vehicle including a hybrid powertrain. The method includes opening or maintaining an open clutch between an engine and a driveline of the vehicle; using a motor / generator of the hybrid powertrain to propel the vehicle; synchronizing an output speed of the engine with an input speed of the driveline; and closing the clutch to connect the engine to the motor / generator when the output speed and the input speed are synchronized.

[0055] In one embodiment, the method includes starting the engine after propelling the vehicle with the motor / generator. In other embodiments, starting the engine includes starting the engine with a starter motor.

[0056] In one embodiment, the output speed is synchronized with the input speed when the output speed is within a predetermined threshold of the input speed. In one embodiment, propelling the vehicle comprises propelling the vehicle after the engine is stopped. In one embodiment, propelling the vehicle comprises propelling the vehicle from a stopped position.

[0057] Another aspect of the present disclosure is a method of starting a vehicle including a hybrid powertrain system. The method includes closing or maintaining closed a clutch between an engine and a driveline of the vehicle; using a motor / generator of the hybrid powertrain system to propel the vehicle while using the motor / generator to spin the engine; and supplying fuel to the engine while using the motor / generator to accelerate the engine.

[0058] In one embodiment, the method includes activating a cylinder decompression system associated with one or more cylinders of the internal combustion engine while the vehicle is being propelled by the motor / generator. In a refinement of the embodiment, the method includes deactivating the cylinder decompression system after initiating engine rotation by the motor / generator.

[0059] In one embodiment, the closed dog clutch is configured to prevent any slip between the output shaft of the engine and the input shaft of the drive train. In one embodiment, the drive train includes an automated manual transmission. In one embodiment, the dog clutch is located between the engine and the motor / generator.

[0060] Another aspect of the present disclosure includes a method of operating a vehicle including a hybrid powertrain. The method includes utilizing the hybrid powertrain to propel the vehicle. When a clutch is closed between an engine and a motor / generator of the powertrain, the method includes controlling the output torque of the engine and the motor / generator to unload a current gear of a transmission of the vehicle; shifting the unloaded transmission to neutral; adjusting the output torque of the engine and the motor / generator so that the engine and the motor / generator operate at a speed appropriate for a new gear of the transmission; and shifting the transmission to the new gear.

[0061] In one embodiment, the method includes adjusting the output torque from the engine and the motor / generator in response to the required torque after shifting the transmission to the new gear. In one embodiment, the dog clutch prevents slippage between the engine and the motor / generator.

[0062] In one embodiment, adjusting the output torque of the engine and the motor / generator includes reducing the speed of the engine and the motor / generator to accommodate the new gear of the transmission. In one embodiment, adjusting the output torque of the engine and the motor / generator includes increasing the speed of the engine and the motor / generator to accommodate the new gear of the transmission. In one embodiment, controlling the output torque of the engine and the motor / generator to unload the current gear includes gradually reducing the output torque to a net zero torque.

[0063] In another aspect of the present disclosure, a method for switching between operating modes of a vehicle including a hybrid powertrain includes: starting the engine of the hybrid powertrain while a clutch located between the engine and a motor / generator of the hybrid powertrain is disengaged; synchronizing an output speed of the engine with an input speed of the powertrain; and when the output speed and the input speed are synchronized, closing the clutch to connect the engine to the motor / generator.

[0064] In another aspect of the present disclosure, a method for switching between operating modes of a vehicle including a hybrid powertrain system includes: controlling the output torque of a motor / generator to unload a current gear of a transmission; shifting the transmission to neutral; controlling the motor / generator to zero speed; closing a clutch between the motor / generator and the engine of the hybrid powertrain system; after closing the clutch, using the motor / generator to start the engine of the hybrid powertrain system; controlling the output speeds of the engine and the motor / generator to engage a desired transmission gear; and shifting the transmission to the desired transmission gear.

[0065] In another aspect of the present disclosure, a method for starting an engine of a hybrid powertrain system for a stationary vehicle includes: shifting the transmission of the hybrid powertrain system to neutral and / or applying a parking brake; disconnecting a clutch between the engine and a motor / generator of the hybrid powertrain system; starting the engine using a starter motor; synchronizing an output speed of the engine with an input speed of the motor / generator; and closing the clutch to connect the engine to the motor / generator when the output speed and the input speed are synchronized.

[0066] In another aspect of the present disclosure, a method for starting an engine of a hybrid powertrain for a stationary vehicle includes: shifting a transmission of the hybrid powertrain to neutral and / or applying a parking brake; closing a clutch between the engine and a motor / generator of the hybrid powertrain; and starting the engine using a starter motor or the motor / generator.

[0067] In another aspect of the present disclosure, an electronic control system is configured to perform any of the methods described herein.

[0068] In another aspect of the present disclosure, a system includes a hybrid powertrain having a meshing clutch between an engine and a motor / generator. The system also includes an electronic control system configured to perform any of the methods described herein.

[0069] Although exemplary embodiments of the present disclosure have been shown and described in detail in the drawings and the foregoing description, this is to be considered illustrative rather than restrictive in nature, and it should be understood that only certain exemplary embodiments have been shown and described, and all changes and modifications that fall within the spirit of the disclosure claimed for protection are protected. It should be understood that although the use of words such as preferred, preferably, preferred, or more preferred utilized in the above description indicates that the features described in this manner may be more desirable, this is not necessary and embodiments without the words are conceivable within the scope of the present invention, which is defined by the appended claims. When reading the claims, it is intended that unless there is an explicit statement to the contrary in the claims, when words such as "one", "a kind", "at least one", or "at least a portion" are used, it is not intended to limit the claims to only one item. When the language "at least a portion" and / or "a portion" is used, the item may include a portion and / or the entire item unless there is an explicit statement to the contrary.

Claims

1. A method for starting a vehicle including a hybrid powertrain, the method comprising: disengaging or maintaining disengaged a clutch between an engine and a drive train of the vehicle; utilizing a motor / generator of the hybrid powertrain system to propel the vehicle; synchronizing an output speed of the engine with an input speed of the drive train; as well as The dog clutch is closed to connect the engine to the motor / generator when the output speed is synchronized with the input speed. 2 . The method of claim 1 , further comprising starting the engine after propelling the vehicle with the motor / generator. 3 . The method of claim 2 , wherein starting the engine comprises starting the engine using a starter motor. 4 . The method of claim 1 , wherein the output speed is synchronized with the input speed when the output speed is within a predetermined threshold of the input speed. The method of claim 1 , wherein propelling the vehicle comprises propelling the vehicle after the engine is stopped. The method of claim 1 , wherein propelling the vehicle comprises propelling the vehicle from a stopped position of the vehicle.

7. A method of starting a vehicle including a hybrid powertrain, the method comprising: closing or maintaining closed a clutch located between an engine and a drive train of the vehicle; utilizing a motor / generator of the hybrid powertrain system to propel the vehicle while utilizing the motor / generator to rotate the engine; as well as The engine is fueled and the motor / generator is used to accelerate the engine. 8 . The method of claim 7 , further comprising activating a cylinder decompression system associated with one or more cylinders of the internal combustion engine while propelling the vehicle with the motor / generator. 9 . The method of claim 8 , further comprising deactivating the cylinder decompression system after initiating engine rotation using the motor / generator.

10. The method of claim 7, wherein the closed dog clutch is configured to prevent any slip between an output shaft of the engine and an input shaft of the driveline.

11. The method of claim 7, wherein the powertrain comprises an automated manual transmission.

12. The method of claim 7 wherein said dog clutch is located between said engine and said motor / generator.

13. A method of operating a vehicle including a hybrid powertrain, the method comprising: The vehicle is propelled using the hybrid powertrain and when a clutch is closed between an engine and a motor / generator of the powertrain: controlling the output torque of the engine and the motor / generator to unload the current gear of the transmission of the vehicle; Shift the unloaded transmission into neutral; adjusting the output torque of the engine and the motor / generator so that the engine and the motor / generator operate at speeds appropriate for a new gear of the transmission; as well as Shifting the transmission to the new gear.

14. The method of claim 13 further comprising adjusting the output torque from the engine and the motor / generator in response to a desired torque after shifting the transmission to the new gear.

15. The method of claim 13, wherein the dog clutch prevents slippage between the engine and the motor / generator. 16 . The method of claim 13 , wherein adjusting the output torque of the engine and the motor / generator comprises reducing the speed of the engine and the motor / generator to accommodate the new gear of the transmission. 17 . The method of claim 13 , wherein adjusting the output torque of the engine and the motor / generator comprises increasing the speed of the engine and the motor / generator to accommodate the new gear of the transmission. 18 . The method of claim 13 , wherein controlling the output torque of the engine and the motor / generator to unload the current gear includes gradually reducing the output torque to a net zero torque.

19. A method of switching between operating modes of a vehicle including a hybrid powertrain, the method comprising: starting the engine of the hybrid powertrain while a dog clutch between the engine and a motor / generator of the hybrid powertrain is disengaged; synchronizing an output speed of the engine with an input speed of the drive train; as well as The dog clutch is closed to connect the engine to the motor / generator when the output speed is synchronized with the input speed.

20. A method of switching between operating modes of a vehicle including a hybrid powertrain, the method comprising: Controlling the output torque of the motor / generator to unload the current gear of the transmission; shifting the transmission to neutral; controlling the motor / generator to zero speed; closing a dog clutch between the motor / generator and an engine of the hybrid powertrain; After closing the dog clutch, starting the engine of the hybrid powertrain using the motor / generator; controlling the output speeds of the engine and the motor / generator for engaging a desired transmission gear; as well as Shifting the transmission to the desired transmission gear.

21. A method of starting an engine of a hybrid powertrain system for a stationary vehicle, the method comprising: shifting a transmission of the hybrid powertrain into neutral and / or applying a parking brake; disengaging a dog clutch between an engine and a motor / generator of the hybrid powertrain; starting the engine using a starter motor; synchronizing an output speed of the engine with an input speed of the motor / generator; as well as The dog clutch is closed to connect the engine to the motor / generator when the output speed is synchronized with the input speed.

22. A method of starting an engine of a hybrid powertrain system for a stationary vehicle, the method comprising: shifting a transmission of the hybrid powertrain into neutral and / or applying a parking brake; closing a dog clutch between the engine and a motor / generator of the hybrid powertrain; as well as The engine is started using a starter motor or the motor / generator.

23. An electronic control system configured to implement any one of claims 1 to 22.

24. A system comprising a hybrid powertrain having a dog clutch between an engine and a motor / generator, the system comprising an electronic control system configured to perform any one of claims 1 to 22.

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