METHOD FOR ADJUSTING THE DRIVETRAIN TORQUE OF A HYBRID VEHICLE

Abstract

A method for controlling a torque output of a hybrid power machine, comprising the following: during a temporary increase in torque in response to a change in the target output torque of a powertrain (200), setting a power machine output torque and a motor output torque in response to a change in the target output torque of the powertrain (200), Adjusting the motor output torque in response to a response to a speed of a drive wheel (285) of a torque converter (206), characterized by Adjusting the power machine output torque for a power machine torque error in response to the settings of a motor torque.

Description

[0001] In hybrid vehicle designs, the vehicle's transmission input torque can be supplied as a sum of the engine torque and the torque of an electric motor, depending on the vehicle's operating conditions. For example, during initial acceleration, the drivetrain torque to a transmission gear may be supplied almost entirely by the motor, with the motor torque then decreasing as increased engine torque becomes available. In this way, the engine torque and motor torque can be varied while maintaining the required torque output. However, if there are errors in the estimated engine torque and / or motor torque, the driver may notice a change in vehicle acceleration as the ratio of engine torque to motor torque changes.Therefore, it may be desirable to accurately estimate the power unit torque and the engine torque.

[0002] For example, publication US 2008 / 0196954A1 discloses a propulsion system for a hybrid vehicle comprising a combustion engine and two electric motors.

[0003] The inventors have recognized the above problems and have developed a method for controlling the torque output of a hybrid power machine according to claim 1, comprising: adjusting the power machine output torque and the motor output torque during a temporary increase in torque in response to a change in the target output torque of the drive train, and further adjusting the motor output torque in response to a change in the speed of the drive wheel of the torque converter.

[0004] By responding to a change in the torque converter's speed, it is possible to provide a target torque at the torque converter's drive gear when the engine torque and the power unit torque change, thus preventing unexpected increases or decreases in drivetrain torque. For example, the engine output torque can be set to respond to a change in the torque converter's speed, ensuring a target torque at the torque converter's drive gear even in the presence of power unit torque estimation errors. Furthermore, the engine torque can compensate for these power unit torque estimation errors, with the power unit torque estimate being updated or adjusted based on the engine torque setting.In this way, a more accurate actual torque of the drive wheel of the torque converter can be provided from a target torque of the drive wheel of the torque converter.

[0005] The present description can provide several advantages. Specifically, the approach can reduce torque disturbances in a powertrain. Furthermore, the approach can improve the efficiency of the hybrid vehicle by allowing the power unit and / or engine to operate under design conditions. Finally, the approach provides compensation for powertrain degradation as the vehicle ages.

[0006] According to the invention, the above advantages are achieved by the features of claim 1. Advantageous embodiments of the invention are described in the dependent claims.

[0007] It is understood that the above summary is provided to introduce, in simplified form, a selection of the concepts that are further described in the detailed description that follows. It is not intended to identify key or essential features of the claimed subject matter, the scope of which is clearly defined by the claims that follow the detailed description. Furthermore, the claimed subject matter is not limited to implementations that eliminate all the disadvantages mentioned above or in any part of the disclosure. Fig. Figure 1 shows a schematic representation of a power machine; Fig. Figure 2 shows an example configuration of the powertrain of a hybrid vehicle; Fig. Figure 3 shows a high-level flowchart for adjusting the power machine torque; Fig. Figure 4 shows a method for setting a DISG torque as a way to compensate for the power engine torque estimation errors; and Fig. Figure 5 is a block diagram of the controller for adjusting the power machine torque.

[0008] This description relates to methods and systems for adjusting and actuating the power machine torque to provide a target output torque of the powertrain of a hybrid vehicle. The hybrid vehicle may contain a power machine and an electric working machine, as described in the Fig. As shown in Figures 1-2, the power engine and the electric working machine can operate together to provide the target input torque to the transmission. Likewise, either the power engine or the electric working machine can be selectively deactivated, allowing either to operate alone to provide the target torque output. As further explained below, the electric working machine can be a DISG or a drivetrain-integrated starter / generator (DISG) integrated into the drivetrain on the same axis as the power engine's crankshaft, rotating whenever the torque converter's drive wheel rotates.The DISG can be integrated into the powertrain so that the mass and inertia of the DISG remain with the powertrain when the DISG is not operating to provide torque to or absorb torque from the powertrain. Fig. Figures 3-5 further illustrate example procedures for adjusting the DISG actuation and engine torques to reduce errors.

[0009] In Fig. 1 comprises an internal combustion engine with 10 multiple cylinders, one of which is in Fig. Figure 1 shows a power unit 10, which is controlled by an electronic controller 12. The power unit 10 includes a combustion chamber 30 and cylinder walls 32, with a piston 36 positioned therein and connected to a crankshaft 40. A flywheel 97 and a ring gear 99 are coupled to the crankshaft 40. The starter 96 includes a pinion shaft 98 and a balance bevel gear 95. The pinion shaft 98 can selectively advance the balance bevel gear 95 to engage with the ring gear 99. The starter 96 can be mounted directly on the front or rear of the power unit. In some examples, the starter 96 can selectively supply torque to the crankshaft 40 via a belt or chain. In one example, the starter 96 is in a base state when it is not engaged with the crankshaft of the power unit.

[0010] It is shown that the combustion chamber 30 is connected to an intake manifold 44 and an exhaust manifold 48 via an intake valve 52 and an exhaust valve 54, respectively. Each intake and exhaust valve can be actuated by an intake cam 51 and an exhaust cam 53. The position of the intake cam 51 can be determined by an intake cam sensor 55. The position of the exhaust cam 53 can be determined by an exhaust cam sensor 57.

[0011] It is shown that the fuel injector 66 is positioned to inject fuel directly into cylinder 30, a process known to those skilled in the art as direct injection. Alternatively, the fuel can be injected into an intake port, a process known to those skilled in the art as port injection. The fuel injector 66 dispenses liquid fuel proportional to the pulse width of the FPW signal from the controller 12. Fuel is supplied to the fuel injector 66 by a fuel system (not shown) comprising a fuel tank, fuel pump, and fuel distributor (not shown). Operating current is supplied to the fuel injector 66 by the driver 68, which responds to the controller 12.Furthermore, it is shown that the intake manifold 44 is connected to an optional electronic throttle valve 62, which sets the position of a throttle plate 64 to control the airflow from the air intake 42 to the intake manifold 44. In one example, a two-stage high-pressure fuel system can be used to generate higher fuel pressures. In some examples, the throttle valve 62 and the throttle plate 64 can be positioned between the intake valve 52 and the intake manifold 44, so that the throttle valve 62 is a channel throttle valve.

[0012] The distributorless ignition system 88 provides a spark to the combustion chamber 30 via a spark plug 92 in response to the controller 12. A universal exhaust gas oxygen sensor (UEGO sensor) 126 is shown coupled to the exhaust manifold 48 upstream of a catalyst 70 (e.g., of an exhaust aftertreatment device). Alternatively, the UEGO sensor 126 can be replaced by a dual-state exhaust gas oxygen sensor.

[0013] Braking of the vehicle wheels or regenerative braking via a DISG can be provided when a brake pedal 150 is applied by a foot 152. A brake pedal sensor 154 provides a signal indicating the brake pedal position to the controller 12. The foot 152 is assisted by the brake booster 140 when the vehicle brakes are applied.

[0014] In one example, catalyst 70 can contain multiple catalyst modules. In another example, multiple exhaust gas purification devices, each with multiple modules, can be used. In one example, catalyst 70 can be a three-way catalyst.

[0015] The Controller 12 is in Fig. Figure 1 shows a conventional microcomputer containing: a microprocessor unit 102, input / output ports 104, a read / write memory 106, a read / write memory 108, a hold memory 110 and a conventional data bus.It has been shown that, in addition to the signals previously discussed, the controller 12 receives various signals from sensors coupled to the engine 10, including: an engine coolant temperature (ECT) from a temperature sensor 112 coupled to the cooling sleeve 114; a position sensor 134 coupled to an accelerator pedal 130 to detect the force exerted by the foot 132; a measurement of the engine manifold pressure (MAP) from a pressure sensor 122 coupled to the intake manifold 44; an engine position sensor from a Hall effect sensor 118 detecting the position of the crankshaft 40; and a measurement of the mass of air entering the engine from a sensor 120. and a measurement of the throttle valve position from a sensor 58. The atmospheric pressure can also be sampled for processing by the controller 12 (the sensor is not shown).A power machine position sensor 118 generates a predetermined number of equally spaced pulses at each revolution of the crankshaft, from which the power machine speed (RPM) can be determined.

[0016] In some examples, the combustion engine in a hybrid vehicle can be coupled to an electric motor / battery system, as in Fig. Figure 2 is shown. Furthermore, other engine configurations can be used in some examples, e.g., a diesel engine.

[0017] During operation, each cylinder in the engine 10 typically goes through a four-stroke cycle: the cycle includes the intake stroke, the compression stroke, the power stroke, and the exhaust stroke. Generally, during the intake stroke, the exhaust valve 54 is closed and the intake valve 52 is open. Air is introduced into the combustion chamber 30 via the intake manifold 44, with the piston 36 moving towards the bottom of the cylinder to increase the volume in the combustion chamber 30. The position in which the piston 36 is near the bottom of the cylinder and at the end of its stroke (e.g., when the combustion chamber 30 is at its largest volume) is typically referred to by those skilled in the field as bottom dead center (BDC). During the compression stroke, the intake valve 52 and the exhaust valve 54 are closed. The piston 36 moves towards the cylinder head to compress the air in the combustion chamber 30.The point at which the piston 36 is at the end of its stroke and closest to the cylinder head (e.g., when the combustion chamber 30 is at its smallest volume) is typically referred to by those skilled in the art as top dead center (TDC). In a process referred to below as injection, fuel is introduced into the combustion chamber. In a process referred to below as ignition, the injected fuel is ignited by known ignition devices, such as a spark plug 92, resulting in combustion. During the power stroke, the expanding gases push the piston 36 back toward top dead center (BDC). The crankshaft 40 converts the piston movement into a torque of the crankshaft. Finally, during the exhaust stroke, the exhaust valve 54 is open to expel the burnt air-fuel mixture to the exhaust manifold 48, with the piston returning to TDC.It should be noted that the above has only been shown as an example and that the opening and / or closing times of the intake and exhaust valves may change, for example to provide positive or negative valve overlap, late closing of the intake valve, or various other examples.

[0018] Fig. Figure 2 is a block diagram of a vehicle 201 and a powertrain 200. The powertrain 200 can be driven by the power unit 10. The power unit 10 can be driven by a Fig. The engine can be started either via the engine starting system shown in Figure 1 or via a DISG 240. Furthermore, the engine 10 can generate or adjust the torque via a torque actuator 204, such as a fuel injector, a throttle valve, etc.

[0019] An engine output torque can be transmitted to an input side of a dual-mass flywheel (DMF) 232. Both the engine speed and the position and speed of the input side of the dual-mass flywheel can be determined via the engine position sensor 118. The dual-mass flywheel 232 can incorporate springs 253 and separate masses 254 to dampen torque disturbances in the drivetrain. The output side of the dual-mass flywheel 232 is shown to be mechanically coupled to the input side of the release clutch 236. The release clutch 236 can be electrically or hydraulically actuated. A position sensor 234 is positioned on the release clutch side of the dual-mass flywheel 232 to detect the output position and speed of the dual-mass flywheel 232. It has been shown that the downstream side of the release clutch 236 is mechanically coupled to the DISG input shaft 237.

[0020] The DISG 240 can be operated to provide torque to the powertrain 200 or to convert the powertrain torque into electrical energy, which is to be stored in an electrical energy storage device 275. The DISG 240 has a higher output power capacity than the one in Fig. The starter 96 is shown. Furthermore, the DISG 240 directly drives the drivetrain 200 or is directly driven by the drivetrain 200. There are no belts, gears, or chains to couple the DISG 240 to the drivetrain 200. Instead, the DISG 240 rotates at the same speed as the drivetrain 200. The electrical energy storage device 275 can be a battery, a capacitor, or an inductor. The downstream side of the DISG 240 is mechanically coupled to the drive wheel 285 of the torque converter 206 via a shaft 241. The upstream side of the DISG 240 is mechanically coupled to the release clutch 236. The torque converter 206 contains a turbine 286 to output torque to the transmission input shaft 270. The transmission input shaft 270 mechanically couples the torque converter 206 to an automatic transmission 208.The torque converter 206 also includes a torque converter lock-up clutch 212 (TCC). When the TCC is engaged, the torque is transmitted directly from the drive wheel 285 to the turbine 286. The TCC is electrically operated by the controller 12. Alternatively, the TCC can be hydraulically engaged. In one example, the torque converter can be considered a component of the transmission. The rotational speed and turbine position of the torque converter can be determined via the position sensor 239. In some examples, 238 and / or 239 can be torque sensors or combination position and torque sensors.

[0021] When the torque converter lock-up clutch 212 is fully disengaged, the torque converter 206 transmits the engine torque to the automatic transmission 208 via a fluid linkage between the torque converter's turbine 286 and its drive gear 285, thereby multiplying the torque. Conversely, when the torque converter lock-up clutch 212 is fully engaged, the engine output torque is transmitted directly to an input shaft (not shown) of the transmission 208 via the torque converter's clutch. Alternatively, the torque converter lock-up clutch 212 can be partially engaged, allowing the amount of torque transmitted to the transmission to be adjusted.The controller 12 can be configured to adjust the amount of torque transmitted by the torque converter 206 by adjusting the torque converter lock-up clutch 212 in response to different operating conditions of the power machine or based on a driver-based power machine operating requirement.

[0022] The automatic transmission 208 includes gear clutches (e.g., gears 1-6) 211 and a forward clutch 210. The gear clutches 211 and the forward clutch 210 can be selectively engaged to propel a vehicle. The torque output from the automatic transmission 208 can, in turn, be transmitted to the rear wheels 216 to propel the vehicle via an output shaft 260. Specifically, the automatic transmission 208 can transmit an input drive torque at the input shaft 270 in response to a driving condition of the vehicle before transmitting an output drive torque to the rear wheels 216.

[0023] Furthermore, a frictional force can be exerted on the wheels 216 by activating the wheel brakes 218. In one example, the wheel brakes 218 can be activated in response to the driver pressing their foot on a brake pedal (not shown). In other examples, the controller 12 or a controller connected to the controller 12 can apply or activate the wheel brakes. Similarly, a frictional force on the wheels 216 can be reduced by releasing the wheel brakes 218 in response to the driver releasing their foot from a brake pedal. Furthermore, the vehicle brakes can exert a frictional force on the wheels 216 via the controller 12 as part of an automated power-machine stopping procedure.

[0024] A mechanical oil pump 214 can be in fluid communication with the automatic transmission 208 to provide hydraulic pressure for engaging the various clutches, such as the forward clutch 210, the gear clutches 211, and / or the torque converter lock-up clutch 212. The mechanical oil pump 214 can be operated in accordance with the torque converter 206 and can be driven, for example, by the rotation of the engine or the DISG via an input shaft 241. Consequently, the hydraulic pressure generated in the mechanical oil pump 214 can increase as the engine speed and / or DISG speed increases, while it can decrease as the engine speed or DISG speed decreases.

[0025] The controller 12 can be configured to receive inputs from the power machine 10, as shown in Fig. 1 is shown in more detail, and accordingly control a torque output of the engine and / or the operation of the torque converter, the transmission, the DISG, the clutches, and / or the brakes. As an example, an engine torque output can be controlled by setting a combination of the timing of the spark, the fuel pulse width, the timing of the fuel pulses, and / or the air charge, by controlling the throttle opening, and / or the timing of the valves, valve lift, and boost for turbocharged or supercharged engines. In the case of a diesel engine, the controller 12 can control the engine torque output by controlling a combination of the fuel pulse width, the timing of the fuel pulses, and the air charge.In all cases, the power machine control can be implemented on a cylinder-by-cylinder basis to control the power machine torque output. The controller 12 can also control the torque output and the generation of electrical energy by the DISG by adjusting the current flowing to or from the field and / or armature windings of the DISG, as is known in the art. The controller 12 can also receive driving surface inclination input information from an inclinometer 281.

[0026] When the idle stop conditions are met, the controller 12 can initiate the shutdown of the engine by cutting off the fuel and spark supply to the engine. In some examples, however, the engine may continue to rotate. To maintain a certain amount of torsion in the transmission, the controller 12 can ground the rotating elements of the transmission 208 to a housing 259 of the transmission and thereby to the vehicle frame. When the engine restart conditions are met and / or a vehicle operator wishes to start the vehicle, the controller 12 can reactivate the engine by resuming combustion in the engine cylinders.

[0027] Consequently, the system adjusts according to the Fig. 1 and Fig. 2. A hybrid vehicle control system comprising: a power machine; an electric working machine; a powertrain disengagement clutch positioned in a powertrain between the power machine and the electric working machine; and a controller containing executable instructions stored in non-volatile memory to adjust an estimate of the power machine torque in response to a fault in the drive gear of the torque converter. The hybrid vehicle control system further comprises additional instructions for adjusting the power machine torque in response to a setting in the output torque of the electric working machine. The hybrid vehicle control system further comprises additional instructions for adjusting the power machine torque based on the power machine torque estimate.

[0028] In some examples, the hybrid vehicle control system further includes additional instructions to adjust the engine torque via a throttle valve, valve timing, fuel quantity, or spark timing. The hybrid vehicle control system also includes additional instructions to determine a target speed of the torque converter drive gear, where the torque converter drive gear error is a speed error of the torque converter drive gear. The hybrid vehicle control system includes the instruction that the torque converter drive gear error is a torque error of the torque converter drive gear.

[0029] In the Fig. Sections 3-5 describe exemplary procedures for operating the powertrain of a hybrid vehicle to generate a target input torque for the transmission. The flowcharts and block diagram according to the Fig. 3-5 generally represent operations that can be enabled by hardware and / or software and that, as such, can be stored as executable instructions in a non-volatile memory of a controller 12, as in the Fig. 1 and Fig. 2 is shown. Fig. Figure 3 illustrates an example procedure 300 in which the DISG can be controlled to generate a target torque of the powertrain during changing conditions of the driver's requirement, including vehicle acceleration.

[0030] In 302, procedure 300 determines a driver request torque. The driver request torque can take the form of a target torque of the transmission drive gear, a power engine braking torque, a wheel torque, or any other drivetrain-related torque. In one example, the position of an accelerator pedal is translated into a target torque of the transmission drive gear via a transfer function that outputs a target torque of the torque converter drive gear when indexed via the accelerator pedal position. A change in the driver request torque can indicate an increasing application of the accelerator pedal by the driver, referred to here as the driver pressing the pedal down. Alternatively, a decrease in the application of the accelerator pedal can be referred to as the driver releasing the pedal. After the driver request torque has been determined, procedure 300 proceeds to 304.

[0031] In 303, the procedure 300 may include determining the vehicle's operating conditions, either by direct sensor sampling or by inference. The operating conditions may include, but are not limited to, the ambient temperature and pressure, engine speed and load, state of charge (SOC) of the energy storage device, vehicle speed, brake pedal position, accelerator pedal position, engine temperature, and the like. After the operating conditions have been determined, the procedure 300 proceeds to 304.

[0032] At 304, the target torques of the engine and the DISG are determined. In an example where the driver request torque is converted into a target torque of the torque converter drive wheel, the target torque of the torque converter drive wheel is achieved by providing an engine torque and a DISG torque that sum to a single value of the target torque of the torque converter drive wheel. The engine torque and the DISG torque can be positive or negative, depending on the powertrain operating mode. For example, the engine target torque can be positive, while the DISG torque can be negative, if the engine is propelling the vehicle while simultaneously charging the energy storage device via the DISG. In some examples, the DISG may only be able to provide a fraction of the torque that the engine can supply.Consequently, the DISG can operate during periods of lower driver demand torque while the engine is switched off and decoupled from the DISG via the powertrain release clutch. Furthermore, DISG operation may be limited based on the state of charge (SOC) of the energy storage device. For example, the DISG cannot supply torque to the powertrain if the SOC of the energy storage device is below a certain threshold. Similarly, the DISG cannot absorb powertrain torque if the SOC of the energy storage device is above a certain threshold state of charge.The specific values ​​of the DISG torque and the engine torque, and / or the ratio of the DISG torque to the engine torque, which, when summed, provide the target torque of the torque converter drive gear, can be empirically determined and stored in a graph or function indexed by vehicle speed, transmission gear, or driver-demand torque. The graph outputs specific target values ​​of the engine torque and the DISG torque. After the target engine torque and the target DISG torque have been determined, the procedure continues from 300 to 306.

[0033] In procedure 306, procedure 300 may further include deciding whether the vehicle should operate in a DISG-only mode. This mode selection may be subject to driver control or may be performed automatically based on the vehicle's operating conditions. The mode selection may include determining whether sufficient DISG output torque is available to provide the driver's requested target torque. If a DISG-only mode is selected, the answer is yes, and procedure 300 continues to 312, where the DISG is instructed to provide the driver's requested target torque before procedure 300 ends. If a DISG-only mode is not selected, the answer is no, and procedure 300 continues to 308.

[0034] In procedure 308, procedure 300 assesses whether the power machine is stopped or not. It can be assessed that the power machine is stopped if one power machine rotation is missing. If procedure 300 assesses that the power machine is stopped, the answer is yes, and procedure 300 continues to 310. Otherwise, the answer is no, and procedure 300 continues to 312.

[0035] At step 310, procedure 300 restarts the engine. The engine can be restarted by turning it via the starter motor or by engaging the drivetrain release clutch and turning it via the DISG transmission. Spark and fuel can also be supplied to the engine so that it combusts air-fuel mixtures. After the engine is started, procedure 300 continues to step 312.

[0036] At step 312, the powertrain release clutch is engaged if it is not already engaged, mechanically coupling the engine and the DISG. The powertrain release clutch can be engaged electrically or hydraulically. Once the powertrain release clutch is engaged, the process continues from step 300 to 314.

[0037] In procedure 300, part 314 involves commanding the engine and motor torque to generate a target input torque for the torque converter drive wheel. The engine target torque represents the amount of torque to be supplied to the drivetrain by the engine, so that when the engine torque is combined with the DISG torque, the target torque for the torque converter drive wheel, or the driver-request target torque, is provided. The engine target torque takes into account various environmental conditions and vehicle operating conditions and / or modes, which may include vehicle speed, engine speed, battery state of charge (SOC), accelerator pedal position, engine coolant temperature, exhaust aftertreatment system status, etc.The engine torque can be adjusted via torque actuators, including the timing of the valves, the timing of the spark, the engine fuel quantity, the timing of the fuel injection, the engine air quantity, the amount of exhaust gas recirculation (EGR), but not limited to these.

[0038] In one example, a model of the engine torque is provided by a table or function containing several stored values ​​of the engine torque at various engine speeds and loads (e.g., an engine air mass charge divided by a theoretical maximum engine air mass charge). The table is indexed by engine speed, and the table entries for the engine torque at the current engine speed are searched to find the location in the table or function that corresponds to the engine target torque. The engine load that provides the engine target torque at the current engine speed is determined by extracting the engine load that corresponds to the location in the table that provides the engine target torque at the current engine speed.In other examples, the engine air mass for a specific engine torque at a specific engine speed is modeled using a regression equation. The engine speed, the target torque, the timing of the sparks, and other variables are input into the regression equation, which outputs the engine air mass. The engine air mass is then translated into a throttle position based on a throttle transfer function. In this way, the engine torque can be adjusted to provide the target engine torque. Once the engine torque has been adjusted, the procedure continues from 300 to 316.

[0039] At 316, the DISG torque is set. The DISG torque represents the amount of torque to be supplied to the drivetrain by the DISG so that, when combined with the engine torque, the target torque of the torque converter drive gear or the driver-request target torque is provided. The DISG torque is increased or decreased by adjusting the amount of current and / or voltage supplied to the DISG. When the DISG is operating in generator mode, the amount of current supplied to a field coil sets the amount of negative torque that the DISG delivers to the drivetrain. In timing chain mode, the DISG torque is set at 316 to provide the difference between the estimated engine torque and the target torque of the torque converter drive gear. For example, if...If the target torque of the torque converter drive wheel is 100 Nm and the estimated engine torque is 80 Nm, the DISG target torque is 20 Nm. After the DISG torque has been set, the procedure continues from step 300 to 318.

[0040] At 318, procedure 300 assesses whether a torque converter lock-up clutch (TCC) is engaged. Procedure 300 can assess that the TCC is engaged if a bit in memory that tracks the TCC state is activated. If the TCC is not engaged, the torque converter characteristics can be used as the basis for correcting the output power machine torque and the estimated power machine torque. If the TCC is engaged, the answer is yes, and procedure 300 continues to 320. Otherwise, the answer is no, and procedure 300 continues to 322 or, in some examples, alternatively to 324.

[0041] In procedure 300, method 320 determines the torque of the torque converter drive gear via a torque sensor positioned on the drive gear. The torque sensor outputs a value of the torque at the drive gear, allowing the engine torque and / or the DISG torque to be adjusted based on the actual torque of the torque converter drive gear to provide the target torque of the drive gear. Alternatively, a torque sensor positioned on the torque converter turbine (at the transmission input) can be used to estimate the drive gear torque. Furthermore, if no torque sensor is available, the powertrain disengagement clutch can be opened. After the torque of the torque converter drive gear is sampled and sent to a controller, such as controller 12, Fig. Once the first step has been transferred, the procedure continues from 300 to 324.

[0042] At 322, procedure 300 adjusts the DISG torque in response to a control loop correction, as in Fig. 4 is described in more detail. In other examples, the engine torque can be set in response to the speed of the torque converter drive wheel or the torque of the torque converter drive wheel, as determined by a torque sensor, instead of or in addition to setting the DISG torque. Therefore, in some examples, step 322 can be omitted. After the DISG torque has been set, the procedure continues from 300 to 324.

[0043] In procedure 300, the engine torque is set according to the vehicle configuration, based on the engine torque error or the DISG torque setting. Because some vehicles may have a torque sensor on the drive gear of the torque converter, while others may not, the engine torque can be set in different ways.

[0044] In an example where the power machine incorporates a sampled or measured torque from the drive wheel of the torque converter, the power machine torque error is determined based on the following equation: Eng_Torq_err=T_impeller−Tmotor−impeller_inertia⋅impeller_acc−Eng_Tor_est

[0045] Eng_Torq_err is the magnitude of the power machine torque error, T_impeller is the sampled or measured torque of the torque converter drive wheel, impeller_inertia is the inertia of the torque converter drive wheel, impeller_acc is the acceleration of the torque converter drive wheel as determined by a torque sensor on the torque converter drive wheel, and Eng_Tor_est is a power machine torque estimated based on the power machine speed and load. In an example, Eng_Tor_est is a power machine model based on a table or function indexed over the power machine speed and load or the air mass, as described in Figure 314. The power machine torque output in Figure 314 is adjusted by the magnitude of the power machine torque error to increase or decrease the power machine torque output.

[0046] In another example, the engine torque error is determined from a model of the torque converter. Specifically, a function representing the torque of the torque converter's drive wheel is indexed against the rotational speed of the drive wheel and the rotational speed of the torque converter's turbine. This function outputs empirically determined values ​​for the torque of the drive wheel. The engine torque error is again determined by the following equation: Eng_Torq_err=T_impeller−Tmotor−impeller_inertia⋅impeller_acc−Eng_Tor_est

[0047] In yet another example, the engine torque can be set based on a DISG torque setting. In this example, the DISG torque setting can be added to the engine so that the engine provides the target engine torque, thus reducing the continuous use of DISG capacity. Specifically, the additional amount of torque provided to the powertrain via the DISG is reduced at the DISG and added to the engine. The DISG torque is reduced by decreasing the DISG current, while the engine torque is increased via an engine torque actuator, such as a throttle valve, spark timing, valve timing, and / or fuel quantity. Once the engine torque or DISG torque has been set, the procedure continues from 300 to 326.

[0048] In document 326, procedure 300 adjusts an estimated engine torque model based on the DISG torque settings or the engine torque error. In one example, the engine torque estimate is set in the table described in document 314 based on the DISG torque or the engine torque error. In another example, the DISG torque setting is multiplied by a predefined value, and the result is added to the table described in document 314 for a specific engine speed and load, adjusting the engine torque output that resulted in the DISG torque to achieve the target speed of the torque converter drive gear. In yet another example, a predefined amount can be added to a value in the table or function described in document 314.In further examples where the engine torque is estimated using a regression equation, a coefficient of the regression equation can be adjusted by a predefined summand or a multiplier. This allows the base values ​​stored in an engine torque estimation model to be adjusted, thereby reducing errors in the engine torque output. After the engine torque estimate has been adjusted, procedure 300 proceeds to the output.

[0049] In Fig. Figure 4 shows a method for adjusting the DISG torque in response to a control loop correction. In Figure 402, the method 400 determines the target torque of the torque converter drive wheel. The target torque of the torque converter drive wheel can be determined from a driver request torque, as described in Figure 302. After the target torque of the torque converter drive wheel has been determined, the method 400 continues to Figure 404.

[0050] In procedure 404, method 400 determines the rotational speed of the torque converter turbine. The rotational speed of the torque converter turbine can be determined via a speed sensor, as shown in Fig. Figure 2 illustrates this. After the rotational speed of the torque converter turbine has been determined, the procedure continues from 400 to 406.

[0051] In procedure 406, method 400 determines a target speed of the drive wheel of the torque converter. Specifically, a model of the torque converter, which takes the form of a table or a function, outputs empirically determined values ​​for the target speed of the drive wheel of the torque converter after being indexed over the speed of the turbine of the torque converter and the target torque of the drive wheel of the torque converter. After the target speed of the drive wheel of the torque converter has been determined, procedure 400 proceeds to 408.

[0052] In procedure 400, method 408 determines the actual rotational speed of the torque converter's drive wheel. The actual rotational speed of the torque converter's drive wheel can be determined via a sensor, as shown in Fig. Figure 2 is shown. After the actual rotational speed of the drive wheel of the torque converter has been determined, the procedure continues from 400 to 410.

[0053] At 410, the procedure sets the DISG torque in response to a speed error of the torque converter drive gear. Specifically, the actual speed of the torque converter drive gear is subtracted from the target speed of the torque converter drive gear to provide a speed error of the torque converter drive gear. This speed error of the torque converter drive gear is acted upon by a feedback controller (e.g., a PID, an LQR, or any other known controller), with the output from the feedback controller being added to the timing chain DISG torque provided at 316 to set the DISG torque.In this way, the DISG torque is adjusted to compensate for any torque error in the power unit, so that the actual torque of the torque converter's drive gear matches the specified torque of the torque converter's drive gear. After the DISG torque has been adjusted, the procedure returns from 400 to 324.

[0054] In Fig. Figure 5 shows a block diagram of a controller for adjusting the engine torque. The controller is an example of how to adjust the engine torque estimate. At 502, the controller 500 determines the driver request torque. The driver request torque can be determined by reading the position of an accelerator pedal or other input device. The driver request torque is routed to 504, where it is converted into a target torque for the drive wheel of the torque converter. In one example, a transfer function converts the driver request torque into a target torque for the drive wheel of the torque converter. The target torque for the drive wheel of the torque converter is routed to 518 and 506.

[0055] In procedure 506, method 500 determines how much of the target torque of the torque converter drive wheel is to be provided by the engine. Furthermore, procedure 506 determines how much of the target torque of the torque converter drive wheel is to be provided by the DISG. In one example, the amount of torque provided to the powertrain via the DISG and the engine is stored in a table of empirically determined values ​​of the engine and DISG torques, indexed based on the target torque of the torque converter drive wheel, the vehicle speed, and the gear. The engine target torque and the DISG target torque can be further modified to account for the state of charge (SOC) of the energy storage device, the engine temperature, and other conditions. Furthermore, the amount of DISG torque can be adjusted in response to the estimated engine torque. For example, the DISG torque can be adjusted to...The torque can be increased or decreased based on the difference between the engine's target torque and the estimated engine torque. Block 506 specifies requirements for the timing chain DISG (T. DISG_des_OL ) and the engine torque (Dsd_eng_T) to the summing block 560 or block 510.

[0056] Block 518 indexes a model of the torque converter, which is stored as a function or a table of empirically determined values ​​of the target speed of the torque converter's drive wheel. The torque converter model is indexed via the current speed of the torque converter's turbine and the target torque of the torque converter's drive wheel. Block 518 outputs a target speed (Dsd_imp_N) of the torque converter's drive wheel to summation block 550.

[0057] At 510, the target torque of the power machine and the power machine torque model are indexed, as at 314 after Fig. 3 is described, where block 510 outputs the torque actuator settings to provide the target engine torque to the engine and drivetrain dynamics block 536. The torque actuator settings can be throttle commands, valve timing commands, fuel injection timing requirements, and / or spark timing commands.

[0058] Block 536 combines the powertrain torque output from the engine and the DISG torque output to provide the target torque of the torque converter drive wheel. Powertrain dynamics are also located within block 536. These dynamics include powertrain inertia, response delays, gear engagement, and other conditions that limit the powertrain's ability to respond precisely as commanded. The actual speed (Act_imp_N) of the torque converter drive wheel is output by block 536 and routed to summation block 550.

[0059] In summing block 550, the actual speed of the torque converter drive wheel is subtracted from the target speed of the torque converter drive wheel, providing a speed error of the torque converter drive wheel. This speed error of the torque converter drive wheel is routed to blocks 516 and 508. In block 516, a feedback controller (e.g., a PID, an LQR, or another controller) responds to the target speed error of the torque converter drive wheel and outputs a DISG torque setting to summing block 560. The output of summing block 560 is a DISG torque command that sets the voltage and / or current supplied to the DISG via the DISG torque actuator 514. In one example, the DISG torque actuator could be an inverter. The DISG torque actuator 514 adjusts the torque output of the DISG 512.The DISG and engine torque are added to the powertrain.

[0060] In section 508, the engine torque model is adjusted in response to the speed error of the torque converter drive gear. For example, the torque converter drive gear speed is multiplied by a factor for a specific drive gear speed that is the same as the engine speed and the DISG speed when the powertrain release clutch is engaged. The result is then added to the engine torque model's estimate for that specific engine speed. Alternatively, the engine torque model estimate can be adjusted by incrementing an engine torque value stored in the engine torque model by a predefined amount.In further examples where the engine torque model is expressed as a regression equation, the coefficients of the regression equation can be adjusted in response to the target speed error of the torque converter's drive wheel. Furthermore, the estimation of the engine torque in response to the DISG command after block 516 can be adjusted, if desired.

[0061] Consequently, the block diagram represents Fig. 5. The adjustment of the engine torque and the DISG torque in response to a driver demand torque is ready. Furthermore, the DISG torque corrects the engine torque estimation errors, whereby the engine torque estimation errors are adjusted based on the speed error of the torque converter's drive wheel.

[0062] The procedures according to the Fig. References 3-5 provide a method for controlling the torque output of a hybrid power unit, comprising: adjusting the power unit output torque and the engine output torque during a temporary torque increase in response to a change in the power unit's target output torque; and further, adjusting the engine output torque in response to a change in the rotational speed of the torque converter's drive wheel. The method includes the torque converter being disengaged during the temporary torque increase. The method further includes supplying the torque output from the torque converter to a multi-speed, rigid-gear automatic transmission. The method includes the engine being a drive unit integrated starter-generator (DISG).

[0063] In some examples, the method includes a clutch in a drivetrain between the engine and the power unit, with the clutch engaged during the temporary torque increase. The method further includes adjusting the power unit torque for a power unit torque error in response to engine torque settings. The method also includes adjusting a model of an estimated power unit output torque based on the speed error of the torque converter drive gear. The method includes adjusting the engine output torque, which involves increasing the engine torque in response to a speed error of the torque converter drive gear.

[0064] The procedures according to the Fig.References 3-5 further include a method for controlling the torque of a hybrid power machine, comprising: supplying a power machine torque and a motor torque to a drive gear of a transmission input; adjusting the motor torque in response to a feedback variable to achieve a target speed of the transmission input drive gear; and adjusting an estimate of the power machine torque in response to the feedback variable. The method further includes determining a target speed of the transmission input drive gear of a torque converter. The method further includes determining a speed of the torque converter turbine and a target torque of the torque converter drive gear at the turbine speed of the torque converter.The method involves using a feedback variable that is the difference between a target speed of the torque converter's drive wheel and the actual speed of the drive wheel. The method further includes determining the actual speed of the torque converter's drive wheel using a sensor. The method also includes adjusting the engine torque in response to the estimated engine torque.

[0065] As the average person in the field understands, the functions or steps represented by the block diagram can be executed by software and / or hardware. Depending on the specific processing strategy, such as event-driven, interrupt-driven, etc., the various functions may be executed in a sequence or pattern that differs from that illustrated in the figures. Similarly, one or more steps or functions may be executed repeatedly, although this is not explicitly illustrated. In one embodiment, the illustrated functions are implemented primarily by software, instructions, or code stored on a computer-readable storage medium and executed by a computer or control module to control the operation of the vehicle.Various conventional sensors or actuators are generally represented by the corresponding blocks of the figures.

Claims

[1] Method for controlling a torque output of a hybrid power machine, comprising: during a temporary increase in torque in response to a change in the target output torque of a powertrain (200), setting a power machine output torque and a motor output torque in response to a change in the target output torque of the powertrain (200), Adjusting the motor output torque in response to a response of a speed of a drive wheel (285) of a torque converter (206), characterized by Adjusting the power machine output torque for a power machine torque error in response to the settings of a motor torque. [2] Method according to claim 1, wherein the torque converter (206) is disengaged during the temporary increase in torque. [3] Method according to claim 1, further comprising supplying the torque output from the torque converter (206) to an automatic transmission (208) with multiple fixed gears. [4] Method according to claim 1, wherein the motor is a starter generator (DISG) (240) integrated into the drive train (200). [5] Method according to claim 1, wherein a clutch (236) is located in the drive train (200) between the motor (240) and the power unit (10), wherein the clutch (236) is engaged during the temporary increase in torque. [6] Method according to claim 1, further comprising setting a model of an estimated power machine output torque based on the speed error of the drive wheel (285) of the torque converter (206). [7] Method according to claim 1, wherein the adjustment of the motor output torque includes adjusting the motor torque in response to a speed error of the drive wheel (285) of the torque converter (206), wherein the speed error of the drive wheel (285) of the torque converter (206) is based on a difference between a target speed of the drive wheel (285) and a measured speed of the drive wheel (285).

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