System and method for battery charging

Abstract

"Systems and methods for battery charging" are provided herein. Methods and systems are provided for accelerating battery charging before entering a zero emission zone. In one example, the battery is charged at a ratio of motor torque obtained from a first electric motor of an electric turbocharger and a second electric motor of a HEV driveline. The ratio is coordinated with adjustment of an exhaust wastegate and an intake throttle to maintain driver torque demand and propel the vehicle while charging the battery.

Description

Technical Field

[0001] The present description generally relates to methods and systems for controlling the state of charge of a system battery in a hybrid electric vehicle.

[0002] Background technology / invention content

[0003] Many parts of the world have implemented varying degrees of low emission zones (LEZ), including zero emission zones (ZEZ). As an example, in some places, older buses and trucks that do not meet certain emission standards are not allowed. In other places, vehicles with internal combustion engines are not allowed, and only hybrid vehicles are allowed to operate in pure electric mode with the internal combustion engine turned off.

[0004] When a vehicle is entering or passing through such an area (e.g., a LEZ or ZEZ), there may be situations where the vehicle battery is not at an optimal charge to reach the destination and return or even pass through the area. For example, there may not be enough margin beyond the estimated energy requirements. Even if an engine-driven battery charging device is available on the vehicle, it may be difficult to charge the battery as quickly as necessary when operating the vehicle in such an area.

[0005] The inventors of this article have recognized that the motor of an electrically assisted supercharged engine system can be used to solve the above-mentioned problems. Specifically, the supercharged engine system can be equipped with an electric motor to provide electric assistance, such as an electric motor / generator connected to a turbocharger. The motor can drive a supercharger compressor or a turbocharger shaft to increase the instantaneous boost pressure delivery during an accelerator pedal event. During situations when rapid battery charging is required, such as just before entering ZEZ, the turbocharger can be operated at a higher power than required, while the electric motor operates in a regenerative mode (recuperating mode) to charge the system battery or other energy storage device at a faster rate than otherwise possible. In addition to speeding up battery charging, the energy recovery possibility of the motor / generator is increased. In addition, the operation of the electric motor of the supercharged engine system can be coordinated with the operation of an electric motor (such as a starter motor) connected to the transmission system of a hybrid electric vehicle to charge the battery while meeting the driver's torque demand.

[0006] In one example, fast battery charging may be achieved by a method for a hybrid vehicle with a boosted engine, the method comprising: in response to anticipated vehicle operation in a low emission zone, charging a system battery via at least one of a first electric motor coupled to a turbocharger shaft and a second electric motor coupled to a vehicle driveline, the charging of the system battery being completed before the vehicle enters a zero emission zone. The same method may also be applied during situations where engine driven battery charging is unavailable, such as when the alternator is degraded.

[0007] As an example, when using engine torque to propel a hybrid electric vehicle, a vehicle controller may predict that the vehicle is about to travel through a low emission zone (LEZ) based on input from a navigation system. The controller may then calculate the amount and rate of charge transfer required for the system battery to enable the use of motor torque to propel the vehicle when in the LEZ. For example, based on the current state of charge (SOC) of the battery, and further based on the distance or duration traveled before entering the LEZ (from the current position) and the distance or duration to be traveled when in the LEZ, the controller may calculate a target SOC for the battery. The amount and rate of charge transfer may then be determined accordingly. In order to achieve accelerated charging of the battery, motor torque from one or both of a first electric motor connected to a turbocharger of the vehicle system and a second electric motor connected to a driveline of the vehicle system may be applied. For example, based on current engine speed-load conditions that vary with driver torque demand, the controller may vary the negative motor torque applied to charge the battery based on the driver torque demand, while maintaining wheel torque using simultaneous wastegate and intake throttle adjustments. For example, during conditions where boosted engine operation does not require electric assistance from the first electric motor, the boost request can be increased beyond the driver torque demand, thereby causing the wastegate to close more than necessary, and the excess turbocharger torque can be used to charge the battery via the first electric motor. As another example, during conditions where torque demand drops, boost pressure can be reduced by absorbing torque from the turbocharger shaft and using it to charge the battery via the first motor, while also absorbing wheel torque and using it to charge the battery via the second motor. The ratio of torque absorbed at the first motor relative to torque absorbed at the second motor can be adjusted based on overall system needs (such as by absorbing more torque via the first motor when the drop in torque demand is greater), and motor conditions (such as by absorbing more torque via the first motor when the temperature of the second motor is above its optimal value).

[0008] In this way, by causing the turbocharger to work harder than required for requested vehicle traction, the system battery can be charged faster than would otherwise be possible. The technical effect of varying the ratio of motor torque derived from the electric assist motor and the hybrid vehicle powertrain electric motor to charge the battery is that a target SOC can be achieved while continuing to provide driver demand torque. By charging the battery prior to entering a low emission zone, emissions compliant vehicle operation can be enabled in a low emission zone. By also using motor torque from the electric assist motor to charge the battery during situations when the alternator degrades, a minimum battery charge can be maintained at all times, thereby improving the performance of the hybrid electric vehicle.

[0009] It should be understood that the above summary of the invention is used to introduce a selection of concepts further described in the detailed description in a simplified form. It is not intended to identify key or essential features of the claimed subject matter, the scope of which is uniquely defined by the claims that follow the detailed description. In addition, the claimed subject matter is not limited to implementations that address any disadvantages noted above or in any part of this disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] Figure 1 An example embodiment of a boosted engine system configured with electric assist is shown.

[0011] Figure 2 Describe the use of Figure 1 A high level flow chart of a supercharged engine system to charge the system battery of a hybrid electric vehicle.

[0012] Figure 3 The following table lists the available options for charging the system battery. Figure 1 Table of example operating modes of a booster system.

[0013] Figure 4 Depicts a high level flow chart for selecting a boosted engine system operating mode to enable battery charging.

[0014] Figure 5 A prophetic example of battery charging using motor torque from one or more of an electric turbocharger and a HEV motor during vehicle operation through a zero-emission zone is depicted. DETAILED DESCRIPTION

[0015] The following description relates to systems and methods for managing battery state of charge in a hybrid vehicle system having an engine with a boost device configured with electric assistance from an electric motor. Figure 1 A non-limiting example of such a system is shown in , where an electric turbocharger is provided in a hybrid electric vehicle. The engine controller may be configured to execute a control routine such as Figures 2 to 4 Example procedures for responding to accelerated battery charging requirements and further based on the operating conditions during charging in multiple operating modes (in Figure 3 Based on the selected operating mode, the controller may use one or more of the electric motor of the electric supercharger and the electric motor of the vehicle's driveline to charge the battery. Figure 5 A prophetic example of coordinating electric assist motor and HEV motor operation during vehicle operation in a low emission zone is shown in FIG.

[0016] Figure 1 Aspects of an example hybrid vehicle system 100 are schematically shown, including an engine system 101 having an engine 10 coupled to a vehicle 102. In the depicted example, the vehicle 102 is a hybrid electric vehicle having multiple torque sources available for one or more wheels 47. In the illustrated example, the powertrain of the vehicle 102 includes the engine 10 and the motor 52. The motor 52 can be a motor or a motor / generator. When one or more clutches 53 are engaged, the engine 10 and the motor 52 are connected to the wheels 47 via the transmission 48. In the depicted example, the (first) clutch 53 is provided between the engine 10 and the motor 52, and the (second) clutch 53 is provided between the motor 52 and the transmission 48. The controller 12 can send a signal to the driver of each clutch 53 to engage or disengage the clutch, thereby connecting or disconnecting the engine 10 with the motor 52 and components connected thereto, and / or connecting or disconnecting the motor 52 with the transmission 48 and components connected thereto. For example, when clutch 53 is engaged, torque from engine 10 can be transferred to wheels 47 via crankshaft 40, transmission 48, and driveline shaft 84. Transmission 48 can be a gearbox, a planetary gear train, or another type of transmission. Transmission 48 can be a stepped transmission including a plurality of gear ratios to allow engine 10 to rotate at a different speed than wheels 47. By varying the torque transfer capacity of first clutch 53 (e.g., the amount of clutch slip), the amount of engine torque transferred to the wheels via driveline shaft 84 can be adjusted.

[0017] The motor 52 can be a HEV motor connected in the transmission between the engine and the transmission. In other examples, the motor 52 can be a crankshaft integrated starter / generator (CISG). The CISG can be connected to the output shaft of the engine so that during the start-up of the hybrid vehicle system, the CISG can provide torque to rotate the engine to facilitate the start-up of the engine. In some cases, the CISG can supply torque output to supplement or replace the engine torque. In addition, as described in detail herein, in some cases, the CISG can supply negative torque output (that is, absorb the transmission torque), which can be converted into electrical energy, such as for charging the system battery.

[0018] The powertrain system can be configured in a variety of ways, including as a parallel hybrid vehicle, a series hybrid vehicle, or a series-parallel hybrid vehicle. In an electric vehicle embodiment, a system power device such as a system battery 45 can be coupled to the drive train. The system battery 45 can be a traction battery that transmits electrical power to the motor 52 to provide torque to the wheels 47. In some embodiments, the motor 52 can also operate as a generator to provide electrical power to charge the system battery 45, such as during braking operations. It will be appreciated that in other embodiments, including non-electric vehicle embodiments, the system battery 45 can be a typical starting, lighting, ignition (SLI) battery coupled to an alternator 46.

[0019] It will be appreciated that although system electrical energy storage device 45 is depicted herein as a battery, in other examples electrical energy storage device 45 may be a capacitor.

[0020] The alternator 46 can be configured to use the engine torque obtained from the crankshaft to charge the system battery 45 during engine operation. In addition, the alternator 46 can power one or more electrical systems of the engine based on their electrical power requirements, such as one or more auxiliary systems, including a heating, ventilation and air conditioning (HVAC) system, lights, an in-vehicle entertainment system, and other auxiliary systems. In one example, the current obtained on the alternator can be constantly changed based on each of the cabin cooling requirements, battery charging requirements, other auxiliary vehicle system requirements, and motor torque. A voltage regulator can be coupled to the alternator 46 to adjust the power output of the alternator based on system usage requirements (including auxiliary system requirements). As detailed herein, during situations when the alternator degrades, battery charging can be enabled via one or more of the motor 52 and the electric assist motor 108.

[0021] In the depicted embodiment, the engine 10 is a supercharged engine equipped with a turbocharger 15. The turbocharger 15 includes a compressor 114, which is mechanically coupled to and driven by a turbine 116 via a shaft 19, and the turbine 116 is driven by expanding the engine exhaust. In one embodiment, the turbocharger can be a twin-scroll device. In another embodiment, the turbocharger can be a variable geometry turbocharger (VGT), in which the turbine geometry is actively changed according to the engine operating conditions. The turbocharger 15 can be further configured as an electric turbocharger with an electric motor 108 (also referred to as an electric assist motor in this article), and the motor 108 is configured to provide electric assistance to the compressor, turbine or turbocharger shaft. In the depicted example, the electric motor 108 is coupled to the shaft 19, but in other examples, the electric motor can be selectively coupled to the compressor 114 or the turbine 116. The electric motor 108 can be powered by an onboard energy storage device such as a system battery 45. The electric motor 108 may additionally or alternatively be powered by the alternator 46. The amount of electric power delivered to the electric motor 108 may be varied to adjust the output of the turbocharger. In one example, the amount of electric power delivered to the electric motor 108 may be increased to increase the speed of the compressor 114. As a result of the electric assistance, the compressor 114 of the turbocharger 15 may be spun up quickly, thereby reducing turbo lag. As shown in FIG. Figure 2 In detail, during selected conditions, the electric motor 108 may also be used to charge the system battery 45. For example, the turbocharger turbine output may be increased beyond what is needed to meet the driver torque demand while negative torque is output from the electric motor 108, which may be converted into electrical energy to charge the battery 45. In yet another example, charging the system battery may be performed by coordinating the negative torque output from the electric motor 108 and the electric machine 52.

[0022] It will be appreciated that while the depicted example shows a turbocharger configured with electric assist, this is not intended to be limiting. In other embodiments, the engine may be a compounded supercharged engine system with an electric supercharger or other boost generator upstream or downstream of the turbocharger in the engine intake. The turbocharger 15 may or may not be configured to receive electric assist from the electric motor 108. In this case, the electric motor that powers the supercharger or other boost device may also be used to brake the compressor and recharge the battery, as described.

[0023] The electric motor 108 may be configured as a motor-generator. Thus, during situations when boost buildup requires electric assistance, the electric motor may provide positive torque to drive the centrifugal compressor of the turbocharger shaft to improve transient boost pressure delivery. However, the electric motor is also capable of energy recovery by "braking" the motor shaft. Therein, negative torque may be applied to the compressor (or shaft), thereby reducing compressor speed and simultaneously charging a system battery (such as battery 45) coupled to the motor. As described in reference Figure 2 In detail, the engine controller can control the timing and amount of negative torque applied from the electric motor to charge the system battery during selected conditions. Using the electric motor in the recuperation mode (absorption) can help charge the system battery faster when needed, and / or maintain the state of charge at a higher level.

[0024] Fresh air is introduced into the engine 10 along the intake passage 42 via the air box 112 and flows to the compressor 114. The air is then compressed at the compressor 114 and introduced into the engine 10. By adjusting the opening of the compressor recirculation valve (CRV) 62, the air compressed by the turbocharger 15 may also be recirculated from the outlet to the inlet of the compressor 114 via the compressor recirculation passage 60. The CRV 62 may be a continuously variable valve or may be a variable discrete valve, and increasing the opening of the CRV 62 may include a solenoid actuating (or energizing) the valve (if discrete) or a motor controller such as an H-bridge (if continuous).

[0025] The compressor 114 is coupled to a throttle valve 20 through a charge air cooler (CAC) 18 (also referred to herein as an intercooler). Air flows from the compressor 114 through the CAC 18 and through the valve 20 to the intake manifold 22. For example, the CAC 18 may be an air-to-air heat exchanger or a water-to-air heat exchanger. The intake manifold pressure (e.g., the pressure of the intake air within the intake manifold) may be determined using a manifold absolute pressure sensor (MAP) 124.

[0026] The intake manifold 22 is coupled to a series of combustion chambers 30 via a series of intake valves (not shown). The combustion chambers are further coupled to an exhaust manifold 36 via a series of exhaust valves (not shown). In the depicted embodiment, a single exhaust manifold 36 is shown. However, in other embodiments, the exhaust manifold may include multiple exhaust manifold sections. A configuration with multiple exhaust manifold sections may enable outflows from different combustion chambers to be directed to different locations in the engine system. Similarly, a configuration with multiple intake manifold sections may enable air originating from different locations to be directed to different combustion chambers (typically cylinder banks) of the engine system. In addition, the intake manifold may have multiple intake throttles (such as one per bank).

[0027] In one embodiment, each of the exhaust valve and the intake valve may be electronically actuated or controlled. In another embodiment, each of the exhaust valve and the intake valve may be cam actuated or controlled. Whether electronically actuated or cam actuated, the timing of the opening and closing of the exhaust and intake valves may be adjusted to obtain desired combustion and emission control performance. For example, the cam timing may be adjusted via a variable cam timing system to move the intake and exhaust cams to a position that provides the best volumetric efficiency for a given operating condition.

[0028] In some embodiments, the engine may also be configured for selective cylinder deactivation, wherein individual cylinder valve operation may be selectively deactivated via individual cylinder valvetrains (including intake and exhaust cams), and individual cylinder fueling may be selectively deactivated via deactivatable fuel injectors.

[0029] Combustion chamber 30 may be supplied with one or more fuels such as gasoline, an alcohol blend, diesel, biodiesel, compressed natural gas, etc. Fuel may be supplied to the combustion chamber via direct injection, port injection, throttle body injection, or any combination thereof. In the depicted example, fuel is provided to each combustion chamber 30 via direct injection of fuel injector 66 (although Figure 1 Only one fuel injector is shown, but each combustion chamber includes a fuel injector coupled thereto. Fuel may be delivered to fuel injector 66 by a fuel system (not shown) including a fuel tank, a fuel pump, and a fuel rail. Combustion may be initiated in the combustion chamber via spark ignition and / or compression ignition.

[0030] like Figure 1 As shown, exhaust gas from exhaust manifold 36 is directed to turbine 116 to drive the turbine. When reduced turbine torque is required, a portion of the exhaust gas may instead be directed through wastegate 90, thereby bypassing the turbine. Wastegate actuator 92 (e.g., wastegate valve) may be actuated open to relieve at least some exhaust pressure from upstream of turbine 116 to a location downstream of turbine 116 via wastegate 90. By reducing the exhaust pressure upstream of turbine 116, turbine speed may be reduced.

[0031] The combined flow from turbine 116 and wastegate 90 flows through emission control device 170. Generally, emission control device 170 may include one or more exhaust aftertreatment components configured to reduce the amount of one or more substances in the exhaust flow. For example, one exhaust aftertreatment component may be configured to capture NO from the exhaust flow when the exhaust flow is lean. x and reduces the captured NO when the exhaust flow is rich x In other examples, the exhaust aftertreatment component may be configured to cause NO xDisproportionately or selectively reduce NO with the help of reducing agents x In yet other examples, emission control device 170 includes a three-way catalyst configured to oxidize residual hydrocarbons and carbon monoxide while reducing NO in the exhaust flow. x Different exhaust aftertreatment catalysts having any such functions may be disposed individually or collectively in the washcoat or elsewhere in emission control device 170. In some embodiments, emission control device 170 may also include a regenerable soot filter configured to trap and oxidize soot particles in the exhaust flow.

[0032] All or a portion of the treated exhaust gas from emission control device 170 may be released to the atmosphere via exhaust conduit 35. However, depending on operating conditions, some exhaust gas may instead be diverted to intake passage 42 via an exhaust gas recirculation (EGR) passage (not shown) including an EGR cooler and an EGR valve. The EGR may be recirculated to the inlet of compressor 114.

[0033] One or more sensors may be coupled to the inlet of the compressor 114. For example, a temperature sensor 55 may be coupled to the inlet of the compressor 114 for estimating the compressor inlet temperature. As another example, a pressure sensor 56 may be coupled to the inlet of the compressor 114 for estimating the pressure of the air entering the compressor. Still other sensors may include, for example, an air-fuel ratio sensor, a humidity sensor, etc. In other examples, one or more of the compressor inlet conditions (such as temperature, humidity, etc.) may be inferred based on engine operating conditions. The sensor may estimate the conditions of the intake air received from the intake duct at the compressor inlet and the intake air recirculated from the upstream of the CAC 18. One or more sensors may also be coupled to the intake duct 42 upstream of the compressor 114 for determining the composition and condition of the intake air entering the compressor. These sensors may include, for example, a pressure sensor 58. In addition, a throttle inlet pressure (TIP) sensor 59 may be coupled downstream of the CAC 18 and upstream of the throttle 20 for estimating the boost pressure delivered to the engine, as measured by the TIP sensor 59.

[0034] During a driver tip-in event, turbo lag may occur when going from engine operation without boost to engine operation with boost in response to driver torque demand. This is attributed to the delay in spinning up the turbine 116, as the turbocharger is a slower-acting compression device. The same situation occurs when the engine is in boost operation, and there is a transient increase in boost demand due to the vehicle driver's increased accelerator pedal application. To reduce this turbo lag, during those selected conditions, the turbocharger 15 may be electrically assisted by receiving positive torque from the electric motor 108. Therein, the electric motor may increase the torque of the turbocharger shaft connecting the turbine to the compressor. Alternatively, when a supercharger is included in the configuration, turbo lag may be reduced by electrically enabling the supercharger using the positive torque received from the electric motor 108.

[0035] During a driver tip-out event, when going from engine operation with boost to engine operation without boost (or reduced boost), a compressor surge may occur. This is because when the throttle 20 is closed, the flow through the compressor 114 is reduced when the accelerator pedal is released. The reduction in forward flow through the compressor can cause surge and reduce turbocharger performance. In addition, surge can cause noise, vibration and harshness (NVH) problems, such as undesirable noise from the engine intake system. In order to enable the torque demand to be quickly reduced in response to the tip-out during the default vehicle operating mode without causing compressor surge, at least a portion of the intake air compressed by the compressor 114 can be recirculated to the compressor inlet. This increases the compressor flow rate to move the operation away from the surge region. Specifically, the CRV 62 can be opened to recirculate (warm) compressed air from the outlet of the compressor 114 upstream of the CAC 18 to the inlet of the compressor 114. In some embodiments, the compressor recirculation system may additionally or alternatively include a recirculation passage for recirculating cooled compressed air from downstream of CAC 18 to the inlet of compressor 114. Additionally, wastegate actuator 92 may be moved to a more open (e.g., fully open) position so that more exhaust flow travels to the tailpipe while bypassing the turbine, thereby accelerating turbine spin down.

[0036] The vehicle system 100 may also include a navigation system 180 communicatively coupled to the controller 12. The navigation system may include, for example, a GPS device. Based on input from the vehicle driver regarding the desired destination, the navigation system 180 may provide route details from the starting point to the desired destination. In addition, traffic information along the route may be provided, as well as weather details at the destination.

[0037] In yet other examples, the navigation system 180 may indicate whether the destination is in a low emission zone (LEZ), such as a zero emission zone (ZEZ), or whether the vehicle route passes through a LEZ. A LEZ may be a geographical area in which engine-operated vehicle propulsion is not allowed. Specifically, only hybrid vehicles that meet predefined emission standards are allowed. A LEZ may be a geographical area defined by latitude and longitude or other geographic coordinates. The coordinates of a LEZ may define an area with a continuous boundary that encloses the entire LEZ. A non-LEZ may be completely outside those coordinates and may completely surround the boundaries of the LEZ. In some examples, the boundaries of a LEZ may be operated 24 hours a day, 7 days a week and may be marked by appropriate road signs. In other examples, a LEZ may be an area that operates as a LEZ during selected hours and as a non-LEZ during other hours. The navigation system 180 may identify a LEZ based on the geographic coordinates of the area relative to the coordinates of the selected route of travel and destination.

[0038] The inventors have recognized that there may be many situations where a system battery such as battery 45 is not at a charge level as high as desired. These situations may include, for example: periods of vehicle operation where electrical energy usage is already particularly high; charging infrastructure is not readily available prior to starting a trip; the vehicle is used to power a load without being operated or otherwise charged; or the vehicle is near an area (such as a LEZ) where engine operation is restricted or prohibited. In such situations, the electric motor 108 of the boost system can be used in a regenerative mode to return additional energy to the battery in addition to what the normal engine-driven charging device can do. In the regenerative mode, the motor that is normally used to drive the turbocharger engine is operated in an absorption mode, where it absorbs energy from the output side of the boost device minus electrical losses, and returns energy to the battery system. This is achieved by operating the turbocharger turbine at a higher load state than required by the current load conditions, where the additional energy is used to recharge. In addition, the battery can be charged using a split ratio of the torque from the electric motor 108 and the motor 52 to speed up charging. The split ratio may be adjusted based on driver torque demand at the time of charge transfer and motor conditions such as temperature and speed of each motor.

[0039] The controller 12 may be included in the control system 14. The illustrated controller 12 receives information from a plurality of sensors 16 (various examples of sensors are described herein) and sends control signals to a plurality of actuators 81 (various examples of actuators are described herein). As an example, the sensors 16 may include an exhaust gas sensor 126 located upstream of the turbine 116, a MAP sensor 124, an exhaust gas temperature sensor 128, an exhaust gas pressure sensor 129, a compressor inlet temperature sensor 55, a compressor inlet pressure sensor 56 (e.g., for measuring P1), a mass air flow (MAF) sensor 57, a pressure sensor 58, and a TIP sensor 59. Sensors such as additional pressure sensors, temperature sensors, air-fuel ratio sensors, and composition sensors may be coupled to various locations in the vehicle system 100. The actuators 81 may include, for example, the throttle 20, the CRV 62, the throttle 108, the wastegate actuator 92, and the fuel injector 66. The controller 12 may receive input data from the various sensors, process the input data, and use various actuators to adjust engine operation based on the received signals and instructions stored on the controller's memory. The controller may use the driver in response to the processed input data based on instructions or code programmed therein, the instructions or code corresponding to one or more programs, such as those described herein with respect to Figure 2 (and Figure 4 As an example, in response to a state of charge below a threshold for battery 45 and a need for accelerated battery charging, the engine may be operated to provide output turbine energy in excess of that required to meet the driver torque demand while the electric motor 108 is operated as a generator to charge the battery 45 using the additional torque available via the turbocharger shaft 19.

[0040] In this way, Figure 1A hybrid vehicle system is implemented by components, the hybrid vehicle system comprising: an engine; a turbocharger connected to an engine intake, the turbocharger comprising an intake compressor connected to an exhaust turbine via a shaft, and a first electric motor connected to the shaft for providing electric assistance to the turbocharger; a second electric motor connected to a vehicle driveline between the engine and a transmission; a waste gate comprising a waste gate driver connected to the exhaust turbine of the turbocharger; an intake throttle connected to the engine intake; a system battery connected to each of the first electric motor and the second electric motor; a navigation system; and a controller. The controller may be configured with computer-readable instructions stored on a non-transitory memory for: in response to input from the navigation system, operating the vehicle system in a first charging mode, wherein the first electric motor is disabled and wherein the battery is charged using motor torque derived from the second electric motor; operating the vehicle system in a second charging mode, wherein the first electric motor provides motor torque to the turbocharger and wherein the battery is charged using motor torque derived from the second electric motor; operating the vehicle system in a third charging mode, wherein the battery is charged using motor torque derived from each of the first electric motor and the second electric motor; operating the vehicle system in a fourth charging mode, wherein the second electric motor is disabled and the battery is charged using motor torque derived from the first electric motor; and selecting a charging mode based on a driver torque demand and the input from the navigation system. In one example, the input from the navigation system includes an amount of charge transferred to the battery required for the vehicle to travel through an upcoming zero-emission zone, the vehicle being propelled through the upcoming zero-emission zone without engine torque. As another example, the selection may include: selecting the first charging mode when the engine speed is below a threshold speed and the engine load is below a threshold load; selecting the second charging mode when the engine speed is below the threshold speed and the engine load is below the threshold load; selecting the third charging mode when the engine speed is above the threshold speed and the engine load is higher than the threshold load by a first amount; and selecting the fourth charging mode when the engine load is higher than the threshold load by a second amount, the second amount being greater than the first amount. In this document, when operating in any of the first charging mode, the second charging mode, the third charging mode, and the fourth charging mode, the engine torque is at least partially used to propel the vehicle.The controller may include additional instructions for: further reducing the opening of the wastegate actuator when the battery is being charged using motor torque obtained from the first electric motor relative to when the first electric motor is providing motor torque to the turbocharger; and reducing the opening of the intake throttle in response to the reducing the opening of the wastegate actuator. In other examples, the controller may maintain the opening of the intake throttle when increasing engine torque to charge the battery via regeneration, and may further adjust one or more other engine operating parameters via signals commanded to corresponding actuators. For example, engine operating settings may be changed via actuation of a crankshaft, a throttle, etc.

[0041] Now go to Figure 2 , method 200 depicts an example procedure for charging a battery of a hybrid vehicle system using torque derived from one or more of an electric turbocharger motor and a vehicle system motor. The method enables the battery to be charged faster than would otherwise be possible. Instructions for implementing method 200 and the remainder of the methods included herein may be executed by a controller based on instructions stored on a memory of the controller and in conjunction with signals received from sensors of the engine system, such as those described above with reference to Figure 1 A controller may use an engine actuator of an engine system to adjust engine operation according to the method described below.

[0042] At 202, the method includes estimating and / or measuring vehicle and engine operating conditions. These include, for example, vehicle speed, driver torque demand, engine speed, battery state of charge (SOC), environmental conditions such as ambient temperature, pressure and humidity, MAF, MAP, etc.

[0043] At 204, the method includes determining whether an electric mode of vehicle operation is expected or predicted. In one example, the electric mode may be expected in response to the vehicle entering or approaching a low emission zone (LEZ) or a zero emission zone (ZEZ) in which engine operation is restricted (or prohibited) and in which hybrid vehicles are required to operate in electric mode. Other conditions in which the electric mode of vehicle operation may be expected include: prolonged vehicle operation in which electrical energy usage is already particularly high, such as, prolonged start and stop driving in heavy traffic or congestion; charging infrastructure is not readily available prior to commencing a drive cycle, such as, when charging stations are not available within a certain radius of a departure point; the vehicle is used to power a load (e.g., a power output load) without being operated or otherwise charged; or the vehicle's alternator is degraded. The vehicle's mileage may be extended by charging the battery when the alternator is degraded, thereby enabling the turbocharger motor to act as a backup alternator. Although the charged battery cannot provide continuous operation under high loads, it can be used for a limited amount of time, thereby improving the vehicle's mileage.

[0044] In one example, a vehicle controller may communicate with a navigation system (e.g., GPS) of the vehicle to predict an upcoming electric operating mode. For example, if a vehicle destination indicated by a vehicle driver or a route selected by a vehicle driver enters or passes through a LEZ, the controller may anticipate an upcoming electric operating mode. Similarly, if a vehicle route changes, such as due to a building or discrete event where a change in vehicle route (e.g., a detour or re-route) causes the vehicle to travel (e.g., briefly) through a LEZ, the controller may anticipate an upcoming electric operating mode. In another example, an electric operating mode may be selected by the vehicle driver, such as by actuating a mode switch or button. In yet other examples, an upcoming electric operating mode may be anticipated whenever the vehicle is advancing in the direction of or parallel to a LEZ.

[0045] As such, a LEZ may be defined by specific geographic coordinates and may define an area in which vehicle propulsion via an internal combustion engine is not permitted. As an example, the boundaries of a LEZ may be defined by longitude and latitude markers, and the LEZ may be completely contained within these markers. Furthermore, the boundaries of a LEZ may be surrounded by non-LEZs in which vehicle propulsion via an internal combustion engine is permitted.

[0046] If electric vehicle mode is not expected, then at 206, the method includes adjusting the engine driver settings based on the engine operating conditions while continuing to operate the vehicle in the engine mode. For example, in response to an increase in driver torque demand while operating in the engine mode, the controller can achieve boost by closing the exhaust valve. In addition, electric assistance can be used to provide other boost pressures, such as operating an electric motor coupled to a turbocharger shaft to reduce turbo lag. The method then ends.

[0047] If electric vehicle mode is expected, then at 208, the method includes determining whether the battery SOC is above a threshold. The threshold may correspond to a defined state of charge that enables the vehicle to propel at least a minimum duration or distance in electric mode. In one example, the threshold is a predefined calibrated threshold required for the electric mode to be enabled, such as 30% SOC. In another example, the threshold is dynamically adjusted based on one or more parameters related to travel through the LEZ. For example, the threshold may be adjusted based on an expected travel duration or distance through the LEZ, the threshold increasing as the expected travel duration or distance increases.

[0048] In one example, the controller may calculate the amount and rate of charge transfer required to pass through the LEZ based on the current geographic location relative to the location of the LEZ and further based on the estimated travel duration or distance through the LEZ. A threshold SOC may then be determined based on the calculated charge transfer amount. For example, the distance of the LEZ relative to the current location may be input into a lookup table, and the charge transfer amount and the corresponding threshold SOC may be output. In other examples, the threshold SOC may be determined based on the location of the LEZ relative to the current location via an algorithm, model, or other function.

[0049] If the battery SOC is above the threshold, then at 210, it can be inferred that the vehicle can pass through the LEZ in electric mode without requiring operation of the internal combustion engine. Thus, one or more motor settings can be adjusted based on vehicle operating conditions. For example, the timing of transitioning from vehicle propulsion using engine torque to vehicle propulsion using motor torque can be adjusted based on duration / distance to the LEZ. Additionally, the motor torque output can be adjusted during travel through the LEZ, such as based on road grade, driver torque demand, and requested vehicle speed.

[0050] If the battery SOC is below the threshold, then at 212, the method includes determining a required charge transfer amount. This includes determining the sum of the required charge amount during the upcoming trip through the LEZ and the charge amount required to move the current SOC to the threshold SOC. For example, the required charge transfer amount and rate to pass through the LEZ may be calculated based on the location of the current geolocation relative to the LEZ and further based on the estimated travel duration or distance through the LEZ.

[0051] At 214, the method includes charging the system battery to a threshold SOC via a ratio of motor torque from an electric assist motor (such as an electric motor providing electric assistance to an electric turbocharger) and an electric motor of an HEV (such as a CISG motor, also referred to as a starter motor) or an electric motor coupled in a driveline between an engine and a transmission (also referred to herein as an HEV motor). Charging the battery using electric assistance from the electric motor may include, at 216, operating the engine and / or turbine with more torque output than required for current operation, and, at 218, using the additional torque to charge the battery via one or more motors. At 220, charging also includes selecting one or more of the electric assist motor and the HEV motor to operate in a generator (energy recovery) mode in order to charge the battery. Figure 4 As detailed in , based on factors such as motor temperature, motor speed, engine speed, and load, the controller can select an operating mode that enables the battery to be charged more quickly while continuing to meet the driver's torque demand. For example, based on operating conditions, the controller can charge the battery via the electric assist motor by generating turbine torque in excess of that required to meet the driver's torque demand, and then charge the battery via the electric assist motor to absorb the excess torque. As another example, the controller can charge the battery via the powertrain motor by absorbing excess wheel torque during deceleration and downhill travel in order to charge the battery. As yet another example, the controller can charge the battery via each of the assist motor and the powertrain motor.

[0052] At 222, after selecting an operating mode and enabling the selected mode, the method includes adjusting one or more vehicle drives during battery charging operations to provide the driver requested torque and any traction requirements. For example, when charging the battery via the electric assist motor, one or more of the exhaust wastegate and intake throttle openings may be adjusted so that the net wheel torque (torque delivered to the wheels via the engine and / or motor) can be maintained at a certain level based on the driver torque demand, while providing an appropriate amount of excess engine and / or turbine torque to charge the battery using the electric assist motor or the HEV powertrain motor or both as conditions require. For example, the exhaust wastegate opening may be reduced more than required to meet the boost demand and produce excess turbine torque, which is then used to increase the ratio of torque absorbed at the electric assist motor to charge the battery. As another example, the intake throttle opening may increase as the wastegate opening decreases to adjust the intake airflow to compensate for the additional pumping work caused by the reduced wastegate opening and meet the driver torque demand. In one example, in response to an increase in the battery state of charge, the vehicle controller may send a signal to a wastegate actuator to move the wastegate valve toward a more closed position (e.g., a fully closed position). Similarly, in response to a decrease in the wastegate opening, the vehicle controller may send a signal to an intake throttle actuator to move the throttle toward a slightly more open position of the throttle.

[0053] Although the above example includes the wastegate valve closed and the throttle valve opened to increase the battery state of charge, it should be understood that this is not intended to be limiting. In yet other examples, the intake throttle valve can be fully open during boost, and only the wastegate valve can be used for boost control. In addition, other actuators such as cams can be operated in conjunction with throttle and wastegate actuation to perform boost and torque control. In this way, various actuators can be adjusted to produce the necessary torque required for recharging the powertrain plus battery.

[0054] Adjusting the vehicle driver may also include adjusting one or more thresholds for an on-board diagnostic (OBD) program. For example, a controller for the engine may be given a higher boost request than required, and energy recovery action at the electric motor may limit actual torque / airflow via a reduction in energy that can enter the compressor from the turbine. This would then require changing the OBD thresholds so that the controller can recognize that this operation of the electric turbocharger may be limiting boost (and that the drop in boost is not due to an air path driver error).

[0055] In this way, by operating the electric boost device in energy regeneration mode when the vehicle approaches a known regulated zero emission zone, battery charging can be accelerated while reducing the need for opportunistic recuperation or frequent engine transients.

[0056] Figure 3 A table 300 is shown depicting an example vehicle operating mode in which a combination of motor torque (positive or negative) from each of the electric assist motor and the HEV motor is used for accelerated battery charging, such as when entering or passing through a zero emission zone. The engine controller may select an operating mode based on various parameters, such as reference Figure 4 As used herein, an electric assist motor refers to an electric motor coupled to a turbocharger shaft for providing electric assist to the turbocharger. As used herein, an HEV motor refers to an engine starter motor (or CISG) or an electric motor coupled to a driveline between an engine and a transmission for propelling a vehicle. It will be appreciated that in Figure 4 In each of the modes shown (Modes 1 to 4), the vehicle is operated with the engine on and wherein at least the engine torque is used to propel the vehicle.

[0057] It will be appreciated that the modes listed below are not intended to be limiting, and that additional other modes are possible. Each of these modes can be used for quasi-steady state to slow down transient conditions. During fast transient conditions, the powertrain controller can utilize both motors (i.e., the turbocharger's electric motor and the powertrain's electric motor) in electric mode to gain performance.

[0058] As an example, the controller may operate the vehicle in a first operating mode (Mode 1) in which the electric assist motor is disabled (i.e., no duty cycle is commanded to the electric assist motor) and the HEV motor is enabled (i.e., a duty cycle is commanded to the HEV motor controller, resulting in a motor torque absorption command) for battery charging. In this mode, the engine may be operated in boost mode without electric assist, such as when more engine torque is being provided than requested. At the same time, the HEV motor may be operated in generator mode to recover additional engine torque and use it to charge the battery. In one example, the first operating mode may be selected when the engine is operating at a low engine speed and a low engine load.

[0059] As another example, the controller can operate the vehicle in a second operating mode (Mode 2) in which the electric assist motor is enabled to provide electric assist and the HEV motor is enabled to charge the battery. In this mode, the engine can be operated with boost with electric assist, such as where the electric motor provides motor torque to supplement the rotation of the turbocharger shaft via the turbine. The electric assist can enable the overall engine torque output to be increased. At the same time, the HEV motor can be operated in generator mode to recover at least a portion of the engine torque (and / or wheel torque) and use it to charge the battery. In one example, the second operating mode can be selected when the engine is operating at a low engine speed and a high engine load.

[0060] As another example, the controller can operate the vehicle in a third operating mode (mode 3) in which each of the electric assist motor and the HEV motor is enabled for battery charging. In this mode, the engine can be operated in which the electric assist motor functions in a generator mode, thereby absorbing torque to charge the battery. In addition, the HEV motor can be operated in a generator mode to recover at least a portion of the engine torque (and / or wheel torque) and use it to charge the battery. In one example, the third operating mode can be selected when the engine is operating at a high engine speed and a high engine load.

[0061] As yet another example, the controller may operate the vehicle in a fourth operating mode (Mode 4) in which the electric assist motor is enabled for battery charging and the HEV motor is disabled. In this mode, the engine may operate with the electric assist motor functioning in a generator mode, absorbing torque to charge the battery. In one example, the fourth operating mode may be selected when the engine is operating at an extremely high engine load.

[0062] In this way, in response to expected vehicle operation in a low emission zone, the controller can charge the system battery via at least one of a first electric motor coupled to a turbocharger shaft and a second electric motor coupled to a vehicle driveline, the charging of the system battery being completed before the vehicle enters the zero emission zone. In one example, the charging can include charging to a threshold state of charge based on the duration and distance of vehicle operation up to and within the low emission zone, wherein a charge transfer rate during charging of the system battery via at least one of the first electric motor and the second electric motor is higher than a charge transfer rate to the battery during regenerative braking. In yet another example, while charging the battery, wheel torque based on a driver torque demand can be maintained via at least one of the first electric motor and the second electric motor. The vehicle controller can also further select at least one of the first electric motor and the second electric motor based on each of the driver torque demand and the engine speed. For example, the selection may include: when operating under a first low engine speed-load condition, selecting the second electric motor to charge the battery while maintaining wheel torque via the engine, wherein the first motor is disabled; when operating under a second low engine speed-high engine load condition, selecting the second electric motor to charge the battery while maintaining wheel torque via the engine, wherein the first motor is enabled; when operating under a third high engine speed-load condition, selecting each of the first electric motor and the second electric motor to charge the battery while maintaining wheel torque via the engine; and when operating under a fourth high engine speed-load condition higher than the third high engine speed-load condition, selecting the first electric motor to charge the battery while maintaining wheel torque via the engine, wherein the second electric motor is disabled. In addition, when operating under the third engine speed-load condition, the controller may adjust the split ratio of the motor torque provided by the first electric motor relative to the motor torque provided by the second electric motor to charge the battery based on one or more of boost pressure, temperature speed, current or torque limit of the motor, or other system constraints. In this article, the adjustment may include: charging the battery at a higher ratio of motor torque from the first electric motor relative to the second electric motor in response to boost pressure being above a threshold pressure, a temperature of the second motor being above a desired threshold, or other powertrain or vehicle conditions. In one example, the second electric motor includes one of: a crankshaft integrated starter motor; and a propulsion motor coupled between the engine and the transmission in the powertrain. In addition, while charging the battery via the first electric motor, the controller may reduce the opening of a wastegate coupled to an exhaust turbine of the turbocharger and adjust the opening of an intake throttle coupled downstream of an intake compressor of the turbocharger to produce a desired level of engine torque.For example, as the amount of charge transferred to the battery increases, the opening of the wastegate may be further reduced, and wherein as the opening of the wastegate decreases, the opening of the intake throttle increases. In yet other examples, the controller may apply a mixture of one or more of the listed modes and other modes not listed herein.

[0063] Now go to Figure 4 , shows an example method 400 for selecting an operating mode of a hybrid vehicle system to achieve rapid battery charging before entering a low emission zone / zero emission zone. The controller may select, for example, based on conditions at each of the motors. Figure 3 By coordinating the operation of each of the electric assist motor of the engine electric supercharger and the electric motor of the powertrain of the hybrid vehicle, battery charging can be accelerated.

[0064] At 402, the method includes confirming that the electric assist motor is available for use. In one example, confirming that the electric assist motor is available for use includes confirming that the motor speed of the electric assist motor is not higher than the operating speed limit. The operating speed limit may be based on the turbocharger assembly shaft speed. In another example, confirming that the electric assist motor is available for use includes confirming that the temperature of the electric assist motor is not higher than the operating temperature limit. For example, the operating temperature limit may be a motor temperature model based on the use current history, engine load, boost level history, and under-hood environment. Various motor faults or other engine system faults may prevent the electric assist motor from being used for regeneration. The limit may be pre-calibrated during engine development or vehicle manufacturing, or may be calibrated after manufacturing but before the vehicle is delivered to the customer. If the motor speed is higher than the speed limit, or if the motor temperature is higher than the temperature limit, then the controller may infer that the electric assist motor is not fully available to provide negative torque to charge the system battery. In another example, if the engine is operated under conditions where the exhaust energy is low, such as in low engine speed-load conditions, when the driver torque demand is low, or when the vehicle or engine is idling, the electric assist motor may not be available.

[0065] If the electric assist motor is not available, then at 404, the method includes confirming that the HEV motor is available for use. In one example, confirming that the HEV motor is available for use includes confirming that the HEV motor (such as a CISG motor or a powertrain motor) does not have any internal faults or diagnostic codes based on motor controller or circuit settings. In another example, confirming that the HEV motor is available for use includes confirming that the temperature of the HEV motor is not higher than an operating temperature limit. The operating temperature limit can be based on a motor controller diagnostic limit or a usage model including internal measurements and / or current history. If the motor speed is higher than a speed limit, or if the motor temperature is higher than a temperature limit, then the controller can infer that the electric assist motor is not fully available to provide negative torque to charge the system battery.

[0066] If neither the electric assist motor or the HEV motor is available, then at 406, the method includes indicating that an electric mode of vehicle operation is not possible at the current time. Therefore, the vehicle may continue to be propelled using engine torque in engine mode. Additionally, it may be indicated that battery charging via the motor may not be possible at this time. The routine then ends.

[0067] If the electric assist motor is not available but the HEV motor is available, then at 408 the method includes selecting a first operating mode (such as Figure 3 Mode 1). At 410, when operating in the first mode, the method includes disabling the electric assist motor (such as by commanding the motor to overcome only the inertia added by the motor on the shaft) and charging the battery via the HEV motor. In this mode, the driver torque demand may be low enough not to require boost pressure, or the boost demand may be low enough that it can be provided by wastegate valve adjustment alone without relying on electric boost assistance. Therefore, when operating in the first mode, the engine torque output may be adjusted to propel the vehicle and charge the battery. Specifically, the engine torque output may be adjusted based on the requested charge transfer to exceed the driver torque demand by a certain amount. Subsequently, excess engine torque may be obtained from the driveline via the HEV motor to charge the battery before entering a low emission zone (or when in a low emission zone). The controller may adjust the motor operation (e.g., speed or output) of the HEV motor by adjusting a command to the HEV motor (such as a duty cycle command), the command being based on the amount of charge to be transferred to the battery. For example, the command may increase as the amount of charge to be transferred increases. In one example, the controller may determine a control signal to be sent to the controller of the HEV motor based on the difference between the current state of charge (SOC) of the battery and the target SOC required before entering the zero emission zone, such as a reference signal. Figure 2Detailed description. The controller may determine the signal based on a calculation using a lookup table, where the input is the desired amount of charge transfer and the output is the motor command. As another example, the controller may make a logical determination (e.g., regarding the motor command) by relying on a model or algorithm based on logic rules that are a function of the amount of charge transfer required to travel through the zero emission zone. The controller may then generate a control signal that is sent to the HEV motor and used to apply negative torque to the driveline during vehicle travel.

[0068] Returning to 402, if the electric assist motor is not available, then at 412, as at 404, the method includes confirming that the HEV motor is available for use. If both the electric assist motor and the HEV motor are available, then at 420, the method includes comparing the engine speed to a threshold speed to confirm that the engine speed is above the threshold speed. The threshold speed may be a calibrated engine speed based on a vehicle or engine efficiency model, accessory load, total charge, vehicle speed, boost capability, and engine load capacity. In another example, the threshold speed corresponds to an engine speed above which the engine torque output requires electric assistance because the boost demand is too high to be met using only throttle valve adjustment.

[0069] If the engine speed is below the threshold speed, then at 422, the method includes selecting a second operating mode (such as Figure 3Mode 2). At 424, when operating in the second mode, the method includes charging the battery via the HEV motor while providing electric assistance for boost pressure control via the electric assist motor. In this mode, the engine speed may not be high enough to meet the torque demand, and therefore the torque demand is met by providing electric boost assistance. Therefore, when operating in the second mode, the engine torque output can be adjusted to propel the vehicle and charge the battery. Specifically, the engine torque output can be adjusted to a boost torque output that exceeds the driver torque demand by a certain amount based on the requested charge transfer. The excess engine torque may or may not be provided by operating the engine with the assistance of the electric assist motor (depending on the ability of the electric assist motor to operate continuously at this level). Subsequently, the excess engine torque can be obtained from the driveline via the HEV motor to charge the battery before entering the low emission zone (or when in the low emission zone). It will be understood that in the second operating mode, the torque output by the HEV motor when charging the battery is higher than the torque output by the electric assist motor when helping to provide the requested boost pressure. The controller may adjust control of the HEV motor via a command to the HEV motor controller (such as a speed command, a torque command, a position command, or a duration of an operation command) based on the amount of charge to be transferred to the battery. For example, the command may increase as the amount of charge to be transferred increases. In one example, the controller may determine a control signal to be sent to the controller of the HEV motor based on a difference between the current state of charge (SOC) of the battery and a target SOC required before entering the zero emission zone, such as a reference signal. Figure 2 Detailed description. The controller may determine the signal based on a calculation using a lookup table, where the input is the desired amount of charge transfer and the output is the motor command. As another example, the controller may make a logical determination (e.g., regarding the command to the motor) by relying on a model or algorithm based on logic rules that are a function of the amount of charge transfer required to travel through the zero emission zone. The controller may then generate a control signal that is sent to the HEV motor and used to apply negative torque to the driveline during vehicle travel.

[0070] If the engine speed is above the threshold speed, then at 426, the method includes selecting a third operating mode (such as Figure 3Mode 3). At 428, when operating in the third operating mode, the method includes charging the battery via each of the electric assist motor and the HEV motor. The split ratio of the negative torque obtained via the HEV motor to charge the battery relative to the negative torque obtained via the electric assist motor can be determined based on individual motor conditions. The ratio can be between 0 and 1, excluding 0 or 1. For example, in response to the temperature of the electric assist motor being higher than the temperature of the HEV motor, the battery can be charged using more negative torque from the HEV motor relative to the electric assist motor. As another example, in response to the speed of the electric assist motor being higher than the speed of the HEV motor, the battery can be charged using more negative torque from the HEV motor relative to the electric assist motor. In yet other examples, as the boost pressure demand of the vehicle increases, the battery can be charged using more negative torque from the HEV motor relative to the electric assist motor.

[0071] Furthermore, the ratio can be actively varied by coordinating motor output with wastegate valve adjustment. For example, in response to driver torque demand, the wastegate valve can be moved to a more closed position to increase the boost output of the engine, thereby allowing a greater portion of the electric field charge transfer to be provided via the HEV motor and reducing the portion of the battery charge transfer provided using the electric assist motor.

[0072] When operating in the third mode, the engine torque output can be adjusted to propel the vehicle and charge the battery. Specifically, the engine torque output can be adjusted to an unboosted torque output that exceeds the driver's torque demand by a certain amount based on the requested charge transfer and split ratio. Excessive engine torque can be provided by operating the engine without assistance from the electric auxiliary engine. Subsequently, excessive engine torque can be obtained from the drive train via the HEV motor. At the same time, the turbine torque output can be adjusted to exceed a certain amount required to meet the desired engine torque based on the requested charge transfer and split ratio. Excessive turbine torque can be obtained from the turbocharger shaft via the electric auxiliary motor to charge the battery before (or when) entering the zero emission zone (or low emission zone). The controller can adjust the motor speed of each of the electric auxiliary motor and the HEV motor by adjusting the command commanded to each motor respectively, and the command is based on the total amount of charge to be transferred to the battery and the split ratio. For example, as the proportion of the charge to be transferred via the HEV motor increases, the command to the HEV motor can be increased. In one example, the controller can determine the control signal sent to the controller of the HEV motor based on the difference between the current state of charge (SOC) of the battery and the target SOC required before entering the zero emission zone and further based on the ratio of the negative torque to be transmitted via the HEV motor. Similarly, the controller can determine the control signal sent to the controller of the electric assist motor based on the difference between the current state of charge (SOC) of the battery and the target SOC required before entering the zero emission zone and further based on the ratio of the negative torque to be transmitted via the electric assist motor. The controller can determine the signal based on a calculation using a lookup table, where the input is the required amount of charge transfer and the output is the motor command. As another example, the controller can make a logical determination (e.g., about a command to the controller) by relying on a model or algorithm based on a logic rule, which is a function of the amount of charge transfer required to travel through the zero emission zone. The controller can then generate a control signal that is sent to the HEV motor and the electric assist motor and is used to apply negative torque to the driveline during vehicle travel.

[0073] Returning to 412, if the electric assist motor is available but the HEV motor is not available, then at 414, the method includes selecting a fourth operating mode (such as Figure 3 Mode 4). In one example, the HEV motor may be unavailable due to an over-temperature condition. At 416, when operating in the fourth mode, the method includes disabling the HEV motor except for opportunistic regenerative braking and charging the battery only via the electric assist motor. Specifically, turbine torque is generated in excess of that required to propel the vehicle, the excess torque being used to charge the battery. In one example, this may occur when the engine is operating at a high engine load.

[0074] When operating in the fourth mode, the turbine torque output can be adjusted to propel the vehicle and charge the battery. Specifically, the turbine torque output can be adjusted to a torque output exceeding a certain amount required to meet the driver's torque demand based on the requested charge transfer. Subsequently, excess turbine torque can be obtained from the turbocharger shaft via the electric assist motor to charge the battery before entering the zero emission zone. The controller can adjust the motor speed of the electric assist motor by adjusting the motor controller command to the motor based on the total amount of charge to be transferred to the battery. For example, as the amount of charge to be transferred via the motor increases, the command to the electric assist motor can be increased. In one example, the controller can determine the control signal sent to the controller of the electric assist motor based on the difference between the current state of charge (SOC) of the battery and the target SOC required before entering the zero emission zone. The controller can determine the signal based on a calculation using a lookup table, where the input is the required charge transfer amount and the output is the necessary motor command (ie, torque or speed command). As another example, the controller can make a logical determination (e.g., about the command to the controller) by relying on a model or algorithm based on a logic rule, which is a function of the amount of charge transfer required to travel through the zero emission zone. The controller may then generate a control signal that is sent to the electric assist motor and used to apply negative torque to the turbocharger shaft during vehicle motion.

[0075] From each of 416, 424, and 428, the program moves to 430, where the method includes adjusting one or more engine actuators, such as intake throttle and exhaust wastegate valve openings, based on the electric assistance provided by the electric assist motor to provide the torque required by the driver and maintain wheel torque based on the driver torque demand. Specifically, the actuator adjustment can be determined based on the operating mode selection (such as, based on whether the second mode, the third mode, or the fourth mode is selected) and based on which motor is used to charge the battery. As an example, during a situation when the electric assist motor is used to charge the battery, the turbine exhaust flow can be reduced by reducing the opening of the wastegate valve, thereby causing more exhaust flow to flow to the turbine and the electric assist motor, and maintaining the speed at a target level by returning excess energy to the battery. In order to maintain the necessary airflow directed to the engine and thereby maintain wheel torque (before reducing the opening of the wastegate valve), the intake throttle opening can be adjusted accordingly. Similarly, a more closed wastegate position and a larger throttle position and other appropriate actuators may be adjusted to allow excess torque to perform the previous actions while also absorbing excess torque where the HEV motor charges the battery.

[0076] In this way, the electric turbocharger can be used in absorption mode by closing the wastegate further than necessary for the desired boost level. By using the braking capability (recuperation) of the electric motor on the electric turbocharger to stop the engine from producing too much boost, the battery can be charged before entering the zero emission zone.

[0077] Now go to Figure 5 , map 500 depicts an example coordinated adjustment between the HEV motor and the electric assist motor to speed up battery charging. Map 500 depicts vehicle speed at graph 502, engine speed at graph 504, intake throttle opening at graph 506, boost pressure at graph 508, and battery state of charge (SOC) at graph 510. The operation of the electric assist motor connected to the electric turbocharger (also referred to as the electric turbine motor herein) is shown at graph 512, the operation of the HEV motor is shown at graph 514, and the wastegate valve adjustment is shown at graph 516. All graphs are depicted over time along the x-axis. Positive torque output indicates that the corresponding motor is operating in motor drive mode, while negative torque output indicates that the corresponding motor is operating in power generation (or absorption) mode.

[0078] Prior to t1, the vehicle is operating in a low torque demand region, so the vehicle is operating at a low engine speed and load (graph 504) corresponding to a lower vehicle speed (graph 502). The intake throttle opening (graph 506) is adjusted based on the torque demand. At this time, the electric mode is not used due to the lower battery SOC (graph 510). Therefore, prior to t1, the engine torque is propelling the vehicle and charging the battery at a low rate. The required boost pressure is low and can be generated by hardware base boost, so the wastegate is fully open (graph 516). In addition, the electric turbine motor is also disabled because boost pressure is not required (graph 512).

[0079] At t1, the driver steps on the accelerator pedal and the torque demand increases to increase vehicle speed. At this point, boosted engine output is required to meet the torque demand. Therefore, the wastegate opening is reduced to spin up the turbine to spin up the compressor, and the intake throttle opening is increased to increase the airflow to the engine. Due to the increased torque demand, it is determined that electric assistance is required. Therefore, the electric turbine motor is also operated to provide positive motor torque to the intake compressor in order to speed up the boost pressure delivery. As a result of operating the electric turbine motor, the battery SOC begins to drop. The electric turbine motor is operated for a short duration since t1 and is then disabled once the boost pressure is high enough.

[0080] At t2, based on the navigation input, it is predicted that the vehicle will enter a zero emission zone where the engine operation is not allowed and the vehicle must operate in electric mode. Specifically, it is predicted to enter the zero emission zone at or around t3. Since the battery SOC is not enough for the expected electric operation mode, at t2, the battery is charged via each of the electric turbine motor and the HEV motor. Specifically, the boost pressure is increased by further reducing the opening of the wastegate to exceed the driver torque demand required to propel the vehicle at the requested vehicle speed. At the same time, the turbine torque is increased by further reducing the opening of the wastegate to exceed the turbine torque required to produce this increased boost. At the same time, the electric turbine motor is enabled and operated in generator mode to use the turbine torque required to meet the increased engine torque demand in order to charge the battery. At the same time, the HEV motor torque is used to charge the battery. The ratio of the motor torque from the HEV motor to the motor torque from the electric turbine motor is adjusted based on the engine speed and load and the individual motor conditions. In the depicted example, relative to the HEV motor, most of the charging motor torque is obtained from the electric turbine motor because the temperature of the HEV motor is higher than its optimal level. This results in a gradual increase in the battery SOC between t2 and t3 such that at t3 the battery SOC is at a level suitable for the predicted electric operating mode.To compensate for the increased airflow required to charge the battery using the HEV motor, the intake throttle opening is slightly increased.

[0081] It will be appreciated that use of motor torque to propel the vehicle or provide electric assistance is illustrated herein via an increase in motor torque (or as positive motor torque), while use of motor torque to charge the battery is illustrated herein via a decrease in motor torque (or as negative motor torque relative to positive motor torque).

[0082] At t3, the vehicle enters the zero emission zone. Engine operation is disabled by closing the intake throttle, fully opening the wastegate, and disabling the electric turbine motor. The end result is a drop in boost pressure and engine speed. Between t3 and t4, the HEV motor continues to operate to propel the vehicle, with the motor torque output by the motor to the driveline changing as the driver torque demand changes. The SOC begins to drop accordingly.

[0083] At t4, the driver torque demand drops as the driver releases the accelerator pedal. At this point, the HEV motor operates as a generator to opportunistically use regenerative braking to charge the battery. At t5, another drop in driver torque demand occurs as the driver releases the accelerator pedal during downhill vehicle travel. The HEV motor operates as a generator to opportunistically use regenerative braking to charge the battery.

[0084] At t6, the vehicle leaves the zero emission zone, but the battery SOC is low. In anticipation of the vehicle passing through the zero emission zone again, the battery is charged using the HEV motor. Also at t6, there is an accelerator pedal event that causes an increase in the driver's torque demand. The torque demand increases and needs to be met by the boosted engine output. Therefore, at t6, the wastegate is fully closed to speed up the turbine spin. In addition, the intake throttle opening is increased to increase the intake airflow. At this time, the boosted engine output is higher than the torque demand so that the vehicle can be propelled, while the excess engine torque is used to charge the battery via the HEV motor.

[0085] At t7, the battery is fully charged, but the torque demand is still high enough to require boosted engine operation. Therefore, at t7, while maintaining the wastegate fully closed, the electric turbine motor output is reduced to provide only electric assist to meet the boost demand. At t8, the driver torque demand is reduced and electric assist is not required to meet the boost demand. Therefore, electric assist is disabled and the wastegate opening is increased.

[0086] In this way, when using engine torque to propel the hybrid vehicle, the controller can provide the driver's required torque by adjusting the wastegate opening while charging the battery using a controlled ratio of motor torque from a first electric motor coupled to the turbocharger shaft and a second electric motor coupled to the vehicle driveline, the wastegate opening being adjusted based on the ratio. The controller can further select the ratio based on the driver torque demand, the ratio of motor torque from the second electric motor increasing as the driver torque demand increases. In addition, when the driver torque demand increases beyond a threshold, the controller can use negative motor torque from the second electric motor to charge the battery while using engine torque in excess of the driver torque demand to propel the vehicle, the excess engine torque being generated when providing positive motor torque from the first electric motor to the turbocharger shaft. In one example, as the ratio of motor torque from the first electric motor increases, the wastegate opening decreases beyond a certain position based on the driver's required torque. In addition, the controller can adjust the intake throttle opening based on each of the wastegate opening, the driver demanded torque, and the motor torque from the first electric motor, wherein the intake throttle opening increases as the wastegate opening decreases beyond the position based on the driver demanded torque. In one example, the charging is in response to the hybrid vehicle actually or about to enter a zero emission zone, wherein the ratio is further selected based on an amount and rate of charge transferred to the battery required prior to entering the zero emission zone.

[0087] In this way, emissions compliance when traveling through a LEZ can be better ensured. Passing a LEZ in electric mode can be achieved by generating excess turbine torque in anticipation of entering a LEZ and using the excess turbine torque to preemptively charge the system battery via the electric assist motor. The technical effect of using the electric assist motor to charge the battery is that the energy recovery capabilities of the motor are better utilized. In addition, the motor is not idling during low torque demand conditions. By adjusting the ratio of electric torque obtained from the electric assist motor and the hybrid vehicle powertrain electric motor to charge the battery, the target SOC required to pass the LEZ can be quickly achieved without causing drivability issues. By using the motor torque from the electric assist motor to charge the battery also during situations when the AC generator is degraded, a nominal battery condition can be provided during all times of hybrid vehicle operation.

[0088] An example method for a hybrid vehicle with a boosted engine, the method comprising: in response to expected vehicle operation in a low emission zone, charging a system battery via at least one of a first electric motor coupled to a turbocharger shaft and a second electric motor coupled to a vehicle driveline, the charging of the system battery being completed before the vehicle enters a zero emission zone. In the foregoing examples, additionally or alternatively, the charging comprises charging to a threshold state of charge, the threshold state of charge being based on a duration and distance of vehicle operation up to and within the low emission zone, wherein a charge transfer rate during charging of the system battery via at least one of the first electric motor and the second electric motor is higher than a charge transfer rate to the battery during regenerative braking. In any or all of the foregoing examples, additionally or alternatively, the method further comprises: while charging the battery, maintaining wheel torque via at least one of the first electric motor and the second electric motor based on a driver torque demand. In any or all of the foregoing examples, additionally or alternatively, the method further comprises: selecting at least one of the first electric motor and the second electric motor based on each of a driver torque demand and an engine speed. In any or all of the foregoing examples, additionally or optionally, the selection includes: when operating under a first, low engine speed-load condition, selecting the second electric motor to charge the battery while maintaining wheel torque via the engine, wherein the first motor is disabled; when operating under a second, low engine speed-high engine load condition, selecting the second electric motor to charge the battery while maintaining wheel torque via the engine, wherein the first motor is enabled; when operating under a third, high engine speed-load condition, selecting each of the first and second electric motors to charge the battery while maintaining wheel torque via the engine; and when operating under a fourth, high engine speed-load condition higher than the third, high engine speed-load condition, selecting the first electric motor to charge the battery while maintaining wheel torque via the engine, wherein the second electric motor is disabled. In any or all of the foregoing examples, additionally or alternatively, when operating under the third engine speed-load condition, the method includes adjusting a split ratio of motor torque provided by the first electric motor relative to motor torque provided by the second electric motor based on one or more of boost pressure, a temperature of the first motor relative to the second motor, and a speed of the first motor relative to the second motor to charge the battery.In any or all of the foregoing examples, additionally or alternatively, the adjustment includes: charging the battery at a higher ratio of motor torque from the first electric motor relative to the second electric motor in response to boost pressure being higher than a threshold pressure, the temperature of the second motor being higher than the temperature of the first motor, or the motor speed of the second motor being higher than the motor speed of the first motor. In any or all of the foregoing examples, additionally or alternatively, the second electric motor includes one of: a crankshaft integrated starter motor; and a propulsion motor coupled between an engine and a transmission in the drivetrain. In any or all of the foregoing examples, additionally or alternatively, the method also includes: while charging the battery via the first electric motor, reducing the opening of a wastegate coupled to an exhaust turbine of the turbocharger, and adjusting the opening of an intake throttle coupled downstream of an intake compressor of the turbocharger. In any or all of the foregoing examples, additionally or alternatively, as the amount of charge transferred to the battery increases, the opening of the wastegate is further reduced, and wherein as the opening of the wastegate decreases, the opening of the intake throttle is increased.

[0089] Another example method includes: when using engine torque to propel a hybrid vehicle, providing a driver-demanded torque by adjusting a wastegate opening while simultaneously charging a battery using a controlled ratio of motor torque from a first electric motor coupled to a turbocharger shaft and a second electric motor coupled to a vehicle driveline, the wastegate opening being adjusted based on the ratio. In the foregoing examples, additionally or alternatively, the method further includes selecting the ratio based on the driver torque demand, the ratio of the motor torque from the second electric motor increasing as the driver torque demand increases. In any or all of the foregoing examples, additionally or alternatively, when the driver torque demand increases beyond a threshold, using negative motor torque from the second electric motor to charge the battery while using engine torque in excess of the driver torque demand to propel the vehicle, the excess engine torque being generated when providing positive motor torque from the first electric motor to the turbocharger shaft. In any or all of the foregoing examples, additionally or alternatively, as the ratio of motor torque from the first electric motor increases, the wastegate opening decreases beyond a certain position based on the driver-demanded torque. In any or all of the foregoing examples, additionally or alternatively, the method further comprises: adjusting an intake throttle opening based on each of the wastegate opening, the driver demanded torque, and the motor torque from the first electric motor, wherein the intake throttle opening decreases as the wastegate opening decreases beyond the position based on the driver demanded torque. In any or all of the foregoing examples, additionally or alternatively, the charging is in response to the hybrid vehicle actually or about to enter a zero emission zone, and wherein the ratio is further selected based on an amount and rate of charge required to be transferred to the battery prior to entering the zero emission zone.

[0090] Another example hybrid vehicle system includes: an engine; a turbocharger coupled to an engine intake, the turbocharger including an intake compressor coupled to an exhaust turbine via a shaft, and a first electric motor coupled to the shaft for providing electric assistance to the turbocharger; a second electric motor coupled to a vehicle driveline between the engine and a transmission; a wastegate including a wastegate actuator coupled to the exhaust turbine of the turbocharger; an intake throttle coupled to the engine intake; a system battery coupled to each of the first electric motor and the second electric motor; a navigation system; and a controller having computer-readable instructions stored on a non-transitory memory, the computer-readable instructions being used to: in response to a command from the controller the input from the navigation system, operating the vehicle system in a first charging mode in which the first electric motor is disabled and in which the battery is charged using motor torque derived from the second electric motor; operating the vehicle system in a second charging mode in which the first electric motor provides motor torque to the turbocharger and in which the battery is charged using motor torque derived from the second electric motor; operating the vehicle system in a third charging mode in which the battery is charged using motor torque derived from each of the first electric motor and the second electric motor; operating the vehicle system in a fourth charging mode in which the second electric motor is disabled and in which the battery is charged using motor torque derived from the first electric motor; and selecting a charging mode based on a driver torque demand and the input from the navigation system. In any or all of the foregoing examples, additionally or alternatively, the input from the navigation system includes an amount of charge transferred to the battery required for the vehicle to travel through an upcoming zero emission zone, the vehicle being propelled through the upcoming zero emission zone without engine torque. In any or all of the foregoing examples, additionally or optionally, the selection includes: selecting the first charging mode when the engine speed is below a threshold speed and the engine load is below a threshold load; selecting the second charging mode when the engine speed is below the threshold speed and the engine load is below the threshold load; selecting the third charging mode when the engine speed is above the threshold speed and the engine load is higher than the threshold load by a first amount; and selecting the fourth charging mode when the engine load is higher than the threshold load by a second amount, the second amount being greater than the first amount.In any or all of the foregoing examples, additionally or optionally, when operating in any of the first charging mode, the second charging mode, the third charging mode, and the fourth charging mode, engine torque is used to propel the vehicle, and wherein the controller includes further instructions for: further reducing the opening of the waste gate actuator when the battery is charged using motor torque obtained from the first electric motor relative to when the first electric motor provides motor torque to the turbocharger; and reducing the opening of the intake throttle in response to the reducing the opening of the waste gate actuator.

[0091] It should be noted that the exemplary control and estimation procedures included herein can be used for various engine and / or vehicle system configurations. The control methods and procedures disclosed herein can be stored as executable instructions in a non-transitory memory and can be implemented by a control system including a controller in combination with various sensors, actuators and other engine hardware. The specific procedures described herein can represent one or more of any number of processing strategies, such as event-driven, interrupt-driven, multi-tasking, multi-threading, etc. As such, the various actions, operations and / or functions shown can be performed in the order shown, performed in parallel, or omitted in some cases. Similarly, the order of processing 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. Depending on the specific strategy used, one or more of the actions, operations and / or functions shown can be repeatedly performed. In addition, the described actions, operations and / or functions can be graphically represented as codes that will be programmed into the non-transitory memory of a computer-readable storage medium of an engine control system, wherein the described actions are implemented by executing instructions in a system including various engine hardware components and an electronic controller.

[0092] It will be appreciated that the configurations and procedures disclosed herein are exemplary in nature, and that these specific embodiments should not be considered in a limiting sense, as many variations are possible. For example, the above-described techniques may be applied to V-6, I-4, I-6, V-12, opposed 4, and other engine types. The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of the various systems and configurations and other features, functions, and / or properties disclosed herein.

[0093] The accompanying claims specifically point out certain combinations and subcombinations regarded as novel and non-obvious. These claims may refer to "an" element or a "first" element or their equivalent. Such claims should not be interpreted to include incorporation of one or more such elements, but do not require or exclude two or more such elements. Other combinations and subcombinations of the disclosed features, functions, elements, or properties may be claimed through amendment of the present claims or through presentation of new claims in this or a related application. Such claims, whether broader, narrower, equal, or different in scope than the original claims, are also deemed to be included in the subject matter of the present disclosure.

[0094] According to the present invention, a method for a hybrid vehicle with a supercharged engine is provided, the method having: in response to expected vehicle operation in a low emission zone, charging a system battery via at least one of a first electric motor coupled to a turbocharger shaft and a second electric motor coupled to a vehicle driveline, the charging of the system battery being completed before the vehicle enters a zero emission zone.

[0095] According to one embodiment, the charging includes charging to a threshold state of charge based on a duration and distance of vehicle operation up to and within the low emissions zone, wherein a charge transfer rate during charging of the system battery via at least one of the first electric motor and the second electric motor is higher than a charge transfer rate to the battery during regenerative braking.

[0096] According to one embodiment, the above invention is further characterized by maintaining a driver requested wheel torque via at least one of the first electric motor and the second electric motor based on a driver torque demand while charging the battery.

[0097] According to one embodiment, the above invention is further characterized by selecting at least one of the first electric motor and the second electric motor based on each of a driver torque demand and an engine speed.

[0098] According to one embodiment, the selection includes: when operating under a first low engine speed-load condition, selecting the second electric motor to charge the battery while maintaining wheel torque via the engine, wherein the first motor is disabled; when operating under a second low engine speed-high engine load condition, selecting the second electric motor to charge the battery while maintaining wheel torque via the engine, wherein the first motor is enabled; when operating under a third high engine speed-load condition, selecting each of the first electric motor and the second electric motor to charge the battery while maintaining wheel torque via the engine; and when operating under a fourth high engine speed-load condition higher than the third high engine speed-load condition, selecting the first electric motor to charge the battery while maintaining wheel torque via the engine, wherein the second electric motor is disabled.

[0099] According to one embodiment, the above invention is further characterized in that, when operating under the third engine speed-load condition, the battery is charged by adjusting the split ratio of the motor torque provided by the first electric motor relative to the motor torque provided by the second electric motor based on one or more of the following items: boost pressure; the temperature of the first motor and the second motor relative to corresponding temperature thresholds; and the motor speed of the first motor and the second motor relative to corresponding speed thresholds.

[0100] According to one embodiment, the adjusting includes charging the battery at a higher ratio of motor torque from the first electric motor relative to the second electric motor in response to boost pressure being above a threshold pressure, the temperature of the second motor being above the corresponding temperature threshold and the temperature of the first motor being within the corresponding temperature threshold, or the motor speed of the second motor being above the corresponding speed threshold and the motor speed of the first motor being within the corresponding threshold.

[0101] According to one embodiment, the second electric motor comprises one of: a crankshaft integrated starter motor; and a propulsion motor coupled between an engine and a transmission in the drive train.

[0102] According to one embodiment, the above invention is also characterized in that when charging the battery via the first electric motor, the opening of the wastegate connected to the exhaust turbine of the turbocharger is reduced, and the opening of the intake throttle connected downstream of the intake compressor of the turbocharger is increased.

[0103] According to one embodiment, as the amount of charge transferred to the battery increases, the opening degree of the wastegate is further reduced, and wherein as the opening degree of the wastegate is reduced, the opening degree of the intake throttle valve is increased.

[0104] According to the present invention, a method includes: when using engine torque to propel a hybrid vehicle, providing driver-demanded torque by adjusting a wastegate opening, while simultaneously charging a battery using a controlled ratio of motor torque from a first electric motor coupled to a turbocharger shaft and a second electric motor coupled to a vehicle driveline.

[0105] According to one embodiment, the above invention is further characterized in that said ratio is selected based on said driver torque demand, said ratio of said motor torque from said second electric motor increasing as said driver torque demand increases.

[0106] According to one embodiment, the above invention is further characterized by using negative motor torque from the second electric motor to charge the battery when the driver torque demand increases beyond a threshold, while using engine torque exceeding the driver torque demand to propel the vehicle, the excess engine torque being generated when providing positive motor torque from the first electric motor to the turbocharger shaft.

[0107] According to one embodiment, as the ratio of motor torque from the first electric motor increases, the wastegate opening is reduced beyond a certain position based on the driver demanded torque.

[0108] According to one embodiment, the above invention is further characterized by adjusting an intake throttle valve opening based on each of the wastegate opening, the driver demanded torque, and the motor torque from the first electric motor.

[0109] According to one embodiment, the above invention is further characterized in that the charging is in response to the hybrid vehicle actually or imminently entering a zero emission zone, and wherein the ratio is selected further based on the amount and rate of charge required to be transferred to the battery prior to entering the zero emission zone.

[0110] According to the present invention, a hybrid vehicle system is provided, the hybrid vehicle system having: an engine; a turbocharger, the turbocharger is coupled to the engine intake, the turbocharger includes an intake compressor coupled to an exhaust turbine via a shaft, and a first electric motor coupled to the shaft for providing electric assistance to the turbocharger; a second electric motor, the second electric motor is coupled to a vehicle driveline; a wastegate, the wastegate includes a wastegate driver coupled to the exhaust turbine of the turbocharger; an intake throttle, the intake throttle is coupled to the engine intake; a system battery, the system battery is coupled to each of the first electric motor and the second electric motor; a navigation system; and a controller, the controller having computer-readable instructions stored on a non-transitory memory, the computer-readable instructions being used to: respond to an incoming from input from the navigation system, operating the vehicle system in a first charging mode wherein the first electric motor is disabled and wherein the battery is charged using motor torque derived from the second electric motor; operating the vehicle system in a second charging mode wherein the first electric motor provides motor torque to the turbocharger and wherein the battery is charged using motor torque derived from the second electric motor; operating the vehicle system in a third charging mode wherein the battery is charged using motor torque derived from each of the first electric motor and the second electric motor; operating the vehicle system in a fourth charging mode wherein the second electric motor is disabled and the battery is charged using motor torque derived from the first electric motor; and selecting a charging mode based on a driver torque demand and the input from the navigation system.

[0111] According to one embodiment, the input from the navigation system comprises an amount of charge transferred to the battery required for the vehicle to travel through an upcoming zero emission zone, the vehicle being propelled through the upcoming zero emission zone without engine torque.

[0112] According to one embodiment, the selection includes: selecting the first charging mode when the engine speed is lower than a threshold speed and the engine load is lower than a threshold load; selecting the second charging mode when the engine speed is lower than the threshold speed and the engine load is lower than the threshold load; selecting the third charging mode when the engine speed is higher than the threshold speed and the engine load is higher than the threshold load by a first amount; and selecting the fourth charging mode when the engine load is higher than the threshold load by a second amount, the second amount being greater than the first amount.

[0113] According to one embodiment, when operating in any one of the first charging mode, the second charging mode, the third charging mode and the fourth charging mode, the engine torque is used to propel the vehicle, and wherein the controller includes additional instructions for: when the battery is charged using the motor torque obtained from the first electric motor, further reducing the opening of the wastegate actuator relative to when the first electric motor provides motor torque to the turbocharger; and adjusting the opening of the intake throttle valve in response to the reducing the opening of the wastegate actuator.

Claims

1. A method for a hybrid vehicle having a supercharged engine, the method comprising: Responsive to anticipated vehicle operation in a low emission zone, a system battery is charged via a first electric motor coupled to a turbocharger shaft or both the first electric motor and a second electric motor coupled to a vehicle driveline, the charging of the system battery being completed before the vehicle enters the low emission zone.

2. The method of claim 1 , wherein the charging comprises charging to a threshold state of charge based on a duration and distance of vehicle operation up to and within the low emission zone, wherein a charge transfer rate during charging of the system battery via the first electric motor or via both the first electric motor and the second electric motor is higher than a charge transfer rate to the battery during regenerative braking.

3. The method of claim 1, further comprising: While charging the battery, a driver requested wheel torque is maintained via the first electric motor or both the first electric motor and the second electric motor based on the driver torque demand.

4. The method of claim 3, further comprising: The first electric motor or both the first electric motor and the second electric motor are selected based on each of a driver torque demand and an engine speed.

5. The method of claim 4, wherein the selecting comprises: selecting each of the first electric motor and the second electric motor to charge the battery while maintaining wheel torque via the engine when operating under a first high engine speed-load condition; as well as When operating in a second high engine speed-load condition that is higher than the first high engine speed-load condition, the first electric motor is selected to charge the battery while maintaining wheel torque via the engine, wherein the second electric motor is disabled.

6. The method of claim 5, further comprising: When operating under the first high engine speed-load condition, the battery is charged by adjusting a split ratio of motor torque provided by the first electric motor relative to motor torque provided by the second electric motor based on one or more of: boost pressure; temperatures of the first and second electric motors relative to corresponding temperature thresholds; and motor speeds of the first and second electric motors relative to corresponding speed thresholds.

7. The method of claim 6, wherein the adjusting comprises: In response to boost pressure being above a threshold pressure, the temperature of the second electric motor being above the corresponding temperature threshold and the temperature of the first electric motor being within the corresponding temperature threshold, or the motor speed of the second electric motor being above the corresponding speed threshold and the motor speed of the first electric motor being within the corresponding threshold, the battery is charged at a higher ratio of motor torque from the first electric motor relative to the second electric motor.

8. The method of claim 1, wherein the second electric motor comprises one of: a crankshaft integrated starter motor; and a propulsion motor coupled between an engine and a transmission in the driveline.

9. The method of claim 1, further comprising: While the battery is charged via the first electric motor, an opening of a wastegate coupled to an exhaust turbine of a turbocharger is reduced, and an opening of an intake throttle coupled downstream of an intake compressor of the turbocharger is increased.

10. The method of claim 9, wherein as the amount of charge transferred to the battery increases, the opening of the wastegate is further reduced, and wherein as the opening of the wastegate is reduced, the opening of the intake throttle is increased.

11. A hybrid vehicle system, the hybrid vehicle system comprising: engine; a turbocharger coupled to the engine intake, the turbocharger comprising an intake compressor coupled to an exhaust turbine via a shaft, and a first electric motor coupled to the shaft for providing electric assistance to the turbocharger; a second electric motor coupled to a vehicle driveline; a wastegate including a wastegate actuator coupled to the exhaust turbine of the turbocharger; an intake throttle valve connected to an air intake port of the engine; a system battery coupled to each of the first electric motor and the second electric motor; Navigation system; as well as A controller having computer readable instructions stored on a non-transitory memory, the computer readable instructions being for: In response to input from the navigation system, operating the vehicle system in a first charging mode wherein the first electric motor is disabled and wherein the battery is charged using motor torque derived from the second electric motor; operating the vehicle system in a second charging mode wherein the first electric motor provides motor torque to the turbocharger and wherein the battery is charged using motor torque derived from the second electric motor; operating the vehicle system in a third charging mode wherein the battery is charged using motor torque derived from each of the first electric motor and the second electric motor; operating the vehicle system in a fourth charging mode in which the second electric motor is disabled and the battery is charged using motor torque derived from the first electric motor; and A charging mode is selected based on a driver torque demand and the input from the navigation system.

12. The system of claim 11, wherein the input from the navigation system includes an amount of charge transferred to the battery required for the vehicle to travel through an upcoming zero emission zone, the vehicle being propelled through the upcoming zero emission zone without engine torque.

13. The system of claim 11, wherein the selection comprises: selecting the first charging mode when the engine speed is lower than a threshold speed and the engine load is lower than a threshold load; When the engine speed is lower than the threshold speed and the engine load is higher than the threshold load, selecting the second charging mode; selecting the third charging mode when the engine speed is above the threshold speed and the engine load is above the threshold load by a first amount; as well as The fourth charging mode is selected when the engine load is greater than the threshold load by a second amount, the second amount being greater than the first amount.

14. The system of claim 11, wherein when operating in any of the first charging mode, the second charging mode, the third charging mode, and the fourth charging mode, engine torque is used to propel the vehicle, and wherein the controller includes further instructions for: When the battery is charged using motor torque obtained from the first electric motor, further reducing the opening of the wastegate actuator relative to when the first electric motor provides motor torque to the turbocharger; and An opening of the intake throttle valve is adjusted in response to the reducing the opening of the wastegate actuator.

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