CN103381823A

CN103381823A - A method and a system for a hybrid electric vehicle

Info

Publication number: CN103381823A
Application number: CN2013101626056A
Authority: CN
Inventors: 亚当·南森·班克; 杰弗里·艾伦·多林; 亚历克斯·奥康纳·吉布森; 丹尼斯·克雷格·里德; 马克·斯蒂文·山崎
Original assignee: Ford Global Technologies LLC
Current assignee: Ford Global Technologies LLC
Priority date: 2012-05-04
Filing date: 2013-05-03
Publication date: 2013-11-06
Anticipated expiration: 2033-05-03
Also published as: DE102013208033A1; CN103381823B

Abstract

The invention provides a system and a method for obtaining torque estimation faults and updating a torque estimation model. In one embodiment, the torque estimation faults are obtained during flame-out of the engine after a disengaging clutch connected between an engine and an electric machine is released. In the following engine operation period, the updated torque estimation module is used for controlling the torque and thus improving the driving feeling and vehicle performance.

Description

The method and system that is used for hybrid vehicle

Cross-reference to related applications

The application requires the preceence of No. the 61/642nd, 877, the U.S. Provisional Patent Application submitted on May 4th, 2012, and its content is hereby expressly incorporated by reference

Technical field

The present invention relates to the system and method be used to the driving performance that improves vehicle and fuel efficiency.The method is especially effective to the driving engine that optionally is connected to motor and change-speed box.

Background technology

Hybrid vehicle provides fuel efficiency and the Vehicle-Miles of Travel that is better than non-hybrid vehicle potentially.An example of hybrid vehicle comprises the driving engine that optionally is connected to motor and change-speed box according to vehicle operation conditions.Driving engine can optionally be connected to motor and change-speed box via the disconnect-type clutch of electric power actuating or hydraulic actuation.Disconnect-type clutch allows motor to provide moment of torsion to wheel under low torque demand condition, and need not to operate driving engine and need not to provide moment of torsion to rotate the driving engine of unburned air-fuel mixture.Disconnect-type clutch also can be used for via motor, the state that driving engine never rotates being restarted.

Via disconnect-type clutch with selection of Motor be connected to driving engine may cause the problem that did not occur in non-hybrid vehicle.For example, engine starting can be introduced vibration and torque ripple to vehicle driveline.If too suddenly use disconnect-type clutch, noise and vibration can be introduced in vehicle driveline, thereby chaufeur is interfered.Similarly, if too suddenly discharge disconnect-type clutch, chaufeur can be interfered equally.Therefore, expectation can improve the disconnect-type clutch operation, in order to can realize a smooth transition between the state that does not use power operation vehicle and use power operation vehicle.

Summary of the invention

The present inventor has realized that above-mentioned shortcoming and develops a kind of method that operates hybrid vehicle, comprising: during the engine off state, and the disconnect-type clutch between the motor of release connection in driving engine and power transmission system of vehicle; And when discharging, power-transfer clutch estimates moment of torsion error disconnect-type clutch discharge after with respect to the deviation of its designated value separately based on engine torque, engine speed and engine retard degree.In this way, can obtain the moment of torsion error.

In an example, during the engine off state, optionally stop using driving engine and the disconnect-type clutch of release connection between the remainder (comprising motor, change-speed box and wheel) of driving engine and power transmission system of vehicle.The speed of a motor vehicle and pedal position when flame-out, can expect to roll stops.Engine controller can determine power-transfer clutch discharge before specified engine torque, make after power-transfer clutch discharges that to keep at power-transfer clutch two ends be zero moment of torsion substantially.In the situation that there is not the engine torque estimation error, after power-transfer clutch discharged, driving engine can be followed the rotating speed/accelerating curve based on specified moment of torsion.Therefore, based on practical engine speeds and the engine retard degree deviation with respect to expectation value, can obtain moment of torsion and cross estimation error and low estimation error.Can engine speed and the function set of actr obtain error.Then, the error that obtains can be used for upgrading the moment of torsion appraising model, and controls engine torque when using power-transfer clutch during follow-up engine restarting.

In this way, can obtain moment of torsion estimation error and improve moment of torsion and control.By obtaining the moment of torsion error and upgrading the moment of torsion appraising model, can reduce the Power Train torque disturbances of hybrid vehicle.In addition, the method can be improved the vehicular drive performance.In addition, the method can reduce the Power Train wearing and tearing, thereby increases the work life of Power Train.

In another embodiment, a kind of method for the hybrid electric vehicle power transmission system comprises: in response to idling-stopping condition, optionally stop using driving engine and the disconnect-type clutch of release connection between driving engine and CISG, CISG is connected to change-speed box and the wheel of Power Train; In engine retard, keep the engine torque designated value; And the rotating speed response of driving engine obtains the engine torque error when discharging based on disconnect-type clutch.

In another embodiment, select the engine torque designated value, make when discharging disconnect-type clutch and make engine retard with the moderating ratio of expecting.

In another embodiment, the rotating speed response acquisition engine torque error based on driving engine comprises: deceleration/decel slows down if driving engine is slower than expectation, obtains engine torque and crosses estimation error; If driving engine slows down faster than the expectation deceleration/decel, obtain the low estimation of engine torque error.

The speed responsive of CISG when in another embodiment, further the engine torque designated value is kept in release simultaneously based on disconnect-type clutch obtains the engine torque error.

Discharge disconnect-type clutch when in another embodiment, the release disconnect-type clutch is included in the speed of a motor vehicle higher than threshold velocity.

In another embodiment, the method comprises that further the function with engine speed obtains the engine torque error.

In another embodiment, the method further comprises: the moment of torsion error update engine torque appraising model that use to obtain, and during follow-up engine restarting based on the engine torque appraising model control engine moment of torsion designated value of upgrading.

In another embodiment, a kind of hybrid vehicle method comprises: after power-transfer clutch discharged, attempting provided zero moment of torsion at disconnect-type clutch two ends, this power-transfer clutch with engine mechanical be connected to motor; And in a period of time after power-transfer clutch discharges based on the velocity curve of driving engine and/or motor, obtain to provide zero required air and the fuel error of moment of torsion.

In another embodiment, attempting provides zero moment of torsion to comprise at power-transfer clutch two ends: determining to provide is the engine torque designated value of zero moment of torsion substantially, and is right after specified determined moment of torsion designated value before power-transfer clutch discharges.

In another embodiment, obtain error based on the speed curves of driving engine and comprise: if the practical engine speeds curve in this section engine speed graph higher than expectation in the time, obtains to cross corresponding to engine torque the error of estimation; If the practical engine speeds curve obtains the error corresponding to the low estimation of engine torque in this section engine speed graph lower than expectation in the time, wherein the engine speed graph of expectation is based on the engine torque designated value.

In another embodiment, the function of setting with engine speed and one or more engine actuators obtains error.

In another embodiment, obtain error and comprise: at the engine idle stopping period, obtain error during higher than threshold value when the speed of a motor vehicle.

With reference to the specific embodiment or by reference to the accompanying drawings with reference to the specific embodiment, above-mentioned advantage of the present utility model and other advantages and feature will become apparent by independent.

Should be appreciated that the summary that provides top is in order to introduce the set of the concept that will further describe in circumstantial letter below with the form of simplifying.This does not also mean that key or the essential feature of identification requirement protection theme, and its scope is limited uniquely by claims.In addition, theme required for protection is not limited to solve the embodiment of any shortcoming above-mentioned or that mention in any part of the present disclosure.

Description of drawings

Can more clearly understand advantage as herein described by independent with reference to the specific embodiment or by reference to the accompanying drawings with reference to the example of specific embodiment reading embodiment, wherein:

Fig. 1 is the schematic diagram of driving engine;

Fig. 2 shows the structure of first example vehicle power drive system;

Fig. 3 shows the structure of second example vehicle power drive system;

Fig. 4 be obtain the moment of torsion estimation error during the engine off state and during follow-up power operation based on the diagram of circuit of the error control engine moment of torsion that obtains;

Fig. 5 is based on engine speed, engine acceleration and engine torque and obtains the diagram of circuit of the method for moment of torsion error with respect to the deviation of its designated value separately;

Fig. 6 is based on one or more selected engine speed setpoint place's engine speed graph and the engine acceleration curve obtains the diagram of circuit of the method for moment of torsion error with respect to the deviation of its expectation curve separately;

Fig. 7 illustrates the exemplary curve that obtains the moment of torsion error based on the method for Fig. 5;

Fig. 8 and Fig. 9 illustrate the exemplary curve that obtains the moment of torsion error based on the method for Fig. 6.

The specific embodiment

The present invention relates to control the power drive system of hybrid vehicle.Hybrid vehicle can comprise that Fig. 1 is to driving engine and motor shown in Figure 3.During vehicle operating, no matter whether have the bent axle (CISG) that is integrated with starter/generator, all can operate driving engine.In addition, no matter whether operate driving engine, all can operate this CISG.During selected engine off state, when driving engine is closed and the power-transfer clutch that driving engine is connected to the vehicle driveline remainder is released, can obtain the engine torque estimation error with respect to the deviation of its expectation value separately based on engine speed response after discharging at power-transfer clutch and/or motor speed response.Engine controller can be configured to executive control program (such as the exemplary process of Fig. 4 to Fig. 6) after power-transfer clutch discharges, and obtains torque deviation with the line deviation of writing music based on engine speed graph deviation, engine retard in a period of time etc. or based on the window (window) of speed.Fig. 7 to Fig. 9 shows power-transfer clutch and discharges the example that obtains afterwards the moment of torsion error based on deviation.The moment of torsion error can driving engine be set and the function of actuator setting obtains, and can be used for upgrading the moment of torsion appraising model.In this way, during follow-up power operation, the control engine moment of torsion is to reduce the power drive system disturbance better.

With reference to Fig. 1, control by engine electronic control system device 12 combustion engine 10 that comprises a plurality of cylinders, one of them cylinder has been shown in Fig. 1.Driving engine 10 comprises cylinder 30 and cylinder wall 32, and piston 36 is positioned at wherein and is connected with bent axle 40.Flywheel 97 and Ring gear 99 are connected to bent axle 40.Starter 96 comprises pinion shaft 98 and miniature gears 95.Pinion shaft 98 optionally impels miniature gears 95 and Ring gear 99 engagements.Shown in cylinder 30 are connected with blow off valve to be connected with dontake pipe with induction maniflod 44 via air inlet valve 52 separately and are connected.Each air inlet valve and blow off valve all can be by inlet cam 51 and exhaust cam 53 operations.The position of inlet cam 51 can be determined by inlet cam sensor 55.The position of exhaust cam 53 can be determined by exhaust cam sensor 57.

Fuel injector 66 is illustrated and injects fuel directly into combustion chamber 30, and this is known as direct injection to those skilled in the art.Alternatively, fuel can be ejected into admission port, and this is known as tuned port injection to those skilled in the art.The pulsewidth of fuel injector 66 and the FPW signal that comes self-controller 12 is delivering liquid fuel pro rata.By the fuel system (not shown) that comprises Fuel Tank, petrolift and fuel rail (not shown), fuel is delivered to fuel injector 66.66 provide working current in response to controller 12 from actuator 68 to fuel injector.In addition, induction maniflod 44 is illustrated with selectable electronic flow regulating valve 62 and is communicated with, and 44 air-flow is controlled from admission port 42 to induction maniflod in the position that this flow regulating valve 62 is adjusted throttle disks 64.In an example, can use the low-pressure direct injection system, this moment, fuel pressure can be promoted to about 20-30bar.Alternatively, can also produce higher fuel pressure with the high-pressure double-stage fuel system.

In response to controller 12, distributor less ignition system 88 provides pilot spark via light-up plug 92 to cylinder 30.Wide territory exhaust oxygen (UEGO) sensor 126 is illustrated the dontake pipe 48 that is connected to catalyst 70 upstreams.Alternatively, the two condition exhaust gas oxygen sensor can substitute UEGO sensor 126.

In an example, conv 70 can comprise a plurality of catalyst bricks.In another example, can use a plurality of emission control systems, each all has a plurality of bricks.In an example, conv 70 can be the ternary form catalyst.

Controller 12 is illustrated as conventional microcomputer in Fig. 1, it comprises microprocessor unit 102, input/output end port 104, read-only memory (ROM) 106, random access memory 108, keep-alive memory device 110 and conventional data bus.controller 12 is illustrated the multi-signal that receives from the sensor that is connected with driving engine 10, except before those signals of discussing, also comprise the engine coolant temperature (ECT) from the temperature sensor 112 that is connected with cooling collar 114, be connected to the signal that acceleration pedal 130 is used for the position transduser 134 of the power that sensing applies by pin 132, observed reading from the manifold pressure (accompanying drawing) of the pressure sensor 122 that is connected to induction maniflod 44, come the signal of engine position sensor of the Hall transducer 118 of self-inductance measurement bent axle 40 positions, observed reading from the air mass that enters driving engine of sensor 120, and from the observed reading of the throttle valve position of sensor 58.Can also come the processing for controller 12 by sensing (not shown sensor) bar pressure.In aspect this explanation preferred, bent axle often circles, and engine position sensor 118 just produces the uniformly-spaced pulse of predetermined quantity, comes thus to determine engine speed (RPM).

In some instances, driving engine can be connected to the electrical motor/battery system in Fig. 2 and hybrid vehicle shown in Figure 3.In addition, in some instances, can also use other engine structures, such as diesel motor.

At run duration, each cylinder in driving engine 10 passes through Otto cycle usually, and this circulation comprises inspiration stroke, compression stroke, expansion stroke and exhaust stroke.Usually, during inspiration stroke, blow off valve 54 is closed and air inlet valve 52 unlatchings.Air enters combustion chamber 30 via induction maniflod 44, and then piston 36 moves to the bottom of cylinder so that the volume increase in combustion chamber 30.Those skilled in the art are called bottom dead point (BDC) with piston 36 near the bottom of cylinder and the position (for example, when combustion chamber 30 is in its maximum volume) of this stroke end usually.During compression stroke, air inlet valve 52 and blow off valve 54 are all closed.Piston 36 moves so that the air compressing in combustion chamber 30 to cylinder head.The point (for example, when cylinder 30 is in its minimum volume) that those skilled in the art are in piston 36 this stroke end and close cylinder head usually is called top dead point (TDC).In hereinafter referred to as the process of spraying, fuel enters combustion chamber.In the process hereinafter referred to as igniting, the fuel of injection is lighted a fire by the known point ignition method such as light-up plug 92, thereby causes burning.During expansion stroke, the gas of expansion pushes back to BDC with piston 36.Bent axle 40 makes the movement of piston change the rotary torque of S. A. into.Finally, during exhaust stroke, blow off valve 54 is opened to discharge to dontake pipe 48 air-fuel mixture and the piston that burnt and is returned to TDC.Note, above shown in as just an example, can change unlatching and/or the timeing closing of air inlet valve and blow off valve, positive valve lap or negative valve lap, air inlet valve time-delay closing or various other examples for example are provided.

Fig. 2 is the block diagram of vehicle driveline 200.Power drive system 200 can be driven by driving engine 10.Driving engine 10 can or start by CISG240 by engine starting system's starting shown in Figure 1.In addition, driving engine 10 can produce or adjust moment of torsion via torque actuators 204 (such as fuel injector, flow regulating valve etc.).

Engine output torque can be sent to the input side of double mass flywheel 232.Engine speed and double mass flywheel input side position and speed can be determined via engine position sensor 118.Double mass flywheel 232 can comprise for the spring and disintegrate-quality piece (mass) (not shown) that suppress the driveline torque disturbance.The outgoing side of double mass flywheel 232 is illustrated the input side that is mechanically attached to disconnect-type clutch 236.Disconnect-type clutch 236 can be by electric actuation or hydraulic actuation.Position transduser 234 is positioned at the disconnect-type clutch side of double mass flywheel 232, with outgoing position and the speed of sensing double mass flywheel 232.The downstream of disconnect-type clutch 236 is illustrated and is mechanically attached to CISG input shaft 237.

Can operate CISG moment of torsion to be provided to power drive system 200 or to convert driveline torque to electrical power storage in apparatus for storing electrical energy 275.Apparatus for storing electrical energy 275 can be battery, cond or inducer.The downstream of CISG240 is mechanically attached to the impeller 285 of turbine transformer 206 via axle 241.The upstream side of CISG is mechanically attached to disconnect-type clutch 236.Turbine transformer 206 comprises to the turbo-machine 286 of axle 270 output torques.Axle 270 is mechanically attached to automatic transmission with hydraulic torque converter 208 with turbine transformer 206.Turbine transformer 206 also comprises turbine transformer bypass lock-up clutch 212 (TCC).When TCC locked, moment of torsion directly was passed to turbo-machine 286 from impeller 285.TCC is by controller 12 electric operatings.Alternatively, TCC can be by hydraulic locking.In an example, turbine transformer can be considered to the parts of change-speed box.Can determine via position transduser 239 rotating speed and the position of transformer turbine machine.In some instances, 238 and/or 239 can or can be the combination of position transduser and torque sensor for torque sensor.

When lockup clutch of converter 212 was separated fully, turbine transformer 206 can be carried via the fluid between transformer turbine machine 286 and turbine transformer impeller 285 engine torque is sent to automatic transmission with hydraulic torque converter 208, thereby realizes multiple torque.On the contrary, when lockup clutch of converter 212 engaged fully, engine output torque can directly be sent to via TCC the input shaft (not shown) of change-speed box 208.Alternatively, lockup clutch of converter 212 can partly engage, thereby realizes the adjustment to the torque capacity that is directly delivered to change-speed box.Controller 12 can be configured in response to various engine operating conditions or according to the power operation request based on chaufeur, adjusts by adjusting lockup clutch of converter the torque capacity that is transmitted by turbine transformer 206.

Automatic transmission with hydraulic torque converter 208 comprises engagement sleeve (for example, gear 1-6) 211 and forward gear power-transfer clutch 210.Engagement sleeve 211 and forward gear power-transfer clutch 210 can optionally be meshed with propelled vehicles.The moment of torsion output of automatic transmission with hydraulic torque converter 208 can transfer to be passed to wheel 216 with propelled vehicles via output shaft 260.Particularly, automatic transmission with hydraulic torque converter 208 can transmit the input driving torque at input shaft 270 places in response to vehicle running state before wheel 216 transmission output driving torques.

In addition, can friction force be applied on wheel 216 by engaging car side brake 218.In an example, car side brake 218 can be engaged in response to the moving pedal (not shown) of chaufeur pin compacting.In other examples, controller 12 or the controller related with controller 12 can engage car side brake.Similarly, in response to chaufeur, pin is discharged from brake pedal, can reduce to be applied to friction force on wheel 216 by unclamping car side brake 218.In addition, as the part of engine stalling program, car brake can apply friction force to wheel 216 via controller 12.

But mechanical oil pump 214 fluids are communicated in automatic transmission with hydraulic torque converter 208 to provide hydraulic pressure to engage a plurality of power-transfer clutchs, such as forward gear power-transfer clutch 210, engagement sleeve 211 and/or lockup clutch of converter 212.For example, mechanical oil pump 214 can operate according to turbine transformer 206, and can drive via the rotation of input shaft 241 by driving engine or CISG.Therefore, the hydraulic pressure that generates in mechanical oil pump 214 can increase along with the increase of engine speed and/or CISG speed, and can reduce along with the reduction of engine speed and/or CISG speed.

Be shown in further detail as Fig. 1, controller 12 can be configured to receive input from driving engine 10, thus the operation of the moment of torsion output of control engine and/or turbine transformer, change-speed box, CISG, power-transfer clutch and/or drg.As an example, open boosting of timing and/or valve timing, valve lift and TC engine or mechanically-sapercharged engine by controlling flow regulating valve, adjust the combination of spark timing, fuel pulse width, fuel impulse timing and/or air inlet, can control engine torque output.In the example of diesel motor, by controlling the combination of fuel pulse width, fuel impulse timing and air inlet, controller 12 can be controlled engine torque output.In all cases, engine control can by cylinder ground execution engine control, be exported with the control engine moment of torsion.As is known to the person skilled in the art, controller 12 can also be exported by control torque, and arrives or control from the magnetic field of CSIG and/or the working current of armature loop the electric energy that is produced by CISG by adjusting.

When satisfying idling-stopping condition, controller 12 can make engine off by cutting out to driving engine feed fuels and igniting.Yet in some instances, driving engine can also continue rotation.In addition, for keep a certain amount of moment of torsion in change-speed box, controller 12 can make the revolving part of change-speed box 208 be grounding to the casing 259 of change-speed box, thereby is grounding to vehicle frame.Particularly, controller 12 can engage one or more transmission clutchs (such as forward gear power-transfer clutch 210), and as described in the U.S. Patent application 12/833,788 that is entitled as " METHOD FOR CONTROLLING AN ENGINE THAT MAY BE AUTOMATICALLY STOPPED " (its full content is hereby expressly incorporated by reference) with the engagement the transmission clutch locking to mission case 259 and vehicle frame.Transmission clutch pressure can change (for example, increasing) with the engagement state of adjustment transmission clutch, and the transmission torque of desired amount is provided.

During engine off, also can adjust car side brake pressure based on transmission clutch pressure, with auxiliary locking (tying up) change-speed box when reducing the moment of torsion that transmits by wheel.Particularly, by use car side brake 218 in the transmission clutch of the one or more joints of locking, can apply opposite power to change-speed box, and then be applied on power transmission, thereby in the situation that need not mobile wheel keep transmission gear have the initiative engagement state and keep transmission gear train in torsional-energy.In an example, during engine off, by the transmission clutch that locking engages, can adjust car side brake pressure to coordinate the application of car side brake.Thus, by adjusting car side brake pressure and clutch pressure, remain on the torque capacity in change-speed box during the capable of regulating engine off.

When satisfying when restarting condition and/or vehicle driver when wanting to start vehicle, controller 12 can be restarted driving engine by recovering cylinder combustion.Further describe as reference Fig. 4 to Fig. 9, driving engine can adopt various ways to start.

Referring now to Fig. 3, show the structure of second example vehicle power drive system.A lot of elements in power drive system 300 are similar with the element in power drive system 200 and adopt identical label.Therefore, for simplicity's sake, omit the explanation to total element between Fig. 2 and Fig. 3.The explanation of Fig. 3 is limited to the element different from the element of Fig. 2.

Power drive system 300 comprises double-clutch-two layshaft gearbox 308.Change-speed box 308 is in fact the hand-operated transmission of automatic operation.Controller 12 operation firsts clutch 310, second clutch 314 and gearshift 315 are to select between gear (for example, the first to the 5th gear) 317.First clutch 310 and second clutch 314 can be selectively opened or close to switch between gear 317.Output shaft 260 is sent to wheel 216 with moment of torsion from change-speed box 308.

The applicant has realized that for the hybrid power system that has disconnect-type clutch (being shown in Figure 2 for 236) for driving engine output place between driving engine and motor (or CISG), can be not only fast but also to connect reposefully and disconnect driving engine be particularly important.Particularly, responsibility for driving engine according to chaufeur input require accelerating vehicle the time connecting engine be particularly important.Similarly, need smooth transition to promote (transparent) pattern conversion smoothly.For achieving the above object, in the whole range of speed of driving engine, transmission system needs effectively to activate approaching zero engine torque.

For example, when engaging or discharge disconnect-type clutch, from the power-transfer clutch to the power system and the moment of torsion of power drive system (be referred to herein as T _Clutch) variation with in order to the clutch torque capacity (torque capacity, torque peak) of keeping engine speed and motor speed proportional (because when clutch lock regularly, the speed of its both sides equates).In the situation that do not consider high frequency damper and flywheel power, following parameter and unit definition separately thereof are:

T _eng: engine output torque, the friction force of indication and thrust (pumping) sum (not comprising I α effect), Nm

I _eng: with the inertia of all parts of engine rotation, Nm (rpm/sec)

N _eng: engine speed, rpm

N _em: motor speed, rpm

α _eng: engine acceleration=d N _eng/ dt, rpm/sec

α _em: motor acceleration=d N _em/ dt, rpm/sec

T _cap: disconnect-type clutch capacity, Nm

T _Clutch: disconnect-type clutch moment of torsion (the actual value of applying), Nm

The output of power-transfer clutch, the input of motor and turbine transformer

When power-transfer clutch made engine stop, this moment of torsion was for negative

T _net: " only " engine torque (it is measured by torque sensor) of power-transfer clutch input side=T _eng-I _eng. α _eng

If clutch fading, applicable following formula:

T _clutch＝T _cap·sign(N _eng-N _em)

T _net＝T _clutch

α_{eng} = \frac{T_{eng} - T_{net}}{I_{eng}} = \frac{T_{eng} - T_{clutch}}{I_{eng}} = \frac{T_{eng} - T_{cap} \cdot sign (N_{eng} - N_{em})}{I_{eng}}

If power-transfer clutch is locked, be suitable for following formula:

α _eng＝α _em，N _eng＝N _em

T _Clutch=T _net=T _eng-I _eng. α _eng, be restricted to | T _Clutch|≤T _cap

In case discharged disconnect-type clutch, clutch capacity will be from enough height so that its a certain value that remains locking be decreased to zero.If the regulation aims of systems is for because releasing clutch makes T _ClutchThe variation that produces is minimum (works as T _capWhen being zero, T _ClutchTo be reduced to zero), need to be before releasing clutch and during releasing clutch, following formula is set up:

T _net＝0

T _eng＝I _eng·α _eng＝I _eng·α _em

In other words, engine torque (not comprising I α effect) should be proportional with motor acceleration.If constant at power-transfer clutch deenergized period motor speed, engine torque should be zero.

As a comparison, in case use power-transfer clutch, clutch capacity just increases to from zero the high value of guaranteeing power-transfer clutch is kept locking.If the regulation aims of systems is for making T owing to using power-transfer clutch _ClutchThe variation that produces is minimum, need to be before using power-transfer clutch and during the power-transfer clutch application, and following formula is set up:

N _eng=N _emSo that need the engine acceleration of lock-up clutch minimum

T _eng＝I _eng·α _eng＝I _eng·α _em

In other words, engine torque (not comprising I α effect) should be proportional with motor acceleration.If motor speed is constant during using power-transfer clutch, engine torque should be zero.

For using power-transfer clutch and releasing clutch, all expectation can be with motor acceleration pro rata with expectation horizontal stable ground excitation engine torque.The motivation needs of this engine torque can overcome (robust) noise factor, engine speed during such as the change between part, application or releasing clutch (for example, in the scope of 600～3000rpm), green (green) engine friction, the engine friction that produced by engine wear over time, the variation of engine oil viscosity (by temperature, machine oil type, machine oil is aging and cause), pressure variation (based on its impact on driving engine pumping loss), air inlet estimation error.

Therefore, minimum for making torque disturbances when using or discharge disconnect-type clutch, need to encourage rightly engine torque.If be achieved, engine acceleration can not change due to the release of power-transfer clutch.Yet if engine torque is higher or lower than delivery value when releasing clutch, engine acceleration can change or be different from the desired acceleration/accel of engine torque based on estimation.This shows and has moment of torsion estimation (or transmission) error.

Therefore, the application's applicant has realized that by the desired engine speed response (comprising engine speed or acceleration/deceleration curve) after power-transfer clutch is discharged and practical engine speeds response and compares, and can obtain the moment of torsion estimation error and be used for upgrading the engine torque appraising model.This allow to obtain moment of torsion error and also is applied in follow-up power operation, such as during using power-transfer clutch when the follow-up engine restarting operation with in follow-up engine off operation the time during releasing clutch.

Referring now to Fig. 4, show the diagram of circuit that the method that operates vehicle driveline and use Fig. 5 to Fig. 6 obtains the illustrative methods of moment of torsion error.The method of Fig. 4 can be used as executable instruction and is stored in Fig. 1 to the non-provisional memory device of controller 12 shown in Figure 3.

In step 402, method 400 is determined running state.Running state can include but not limited to torque demand, engine speed, engine torque, motor or CISG speed and moment of torsion, the speed of a motor vehicle, ambient temperature and pressure and battery charging state.Torque demand can draw from acceleration pedal 130 shown in Figure 1 and controller 12.Method 400 proceeds to step 404 after running state is determined.

In step 404, can determine whether to satisfy engine stop condition.Can ask engine stop by operated key or key-press input with unique function of asking engine starting.Alternatively, can automatically ask engine stop based on running state by controller 12.As an example, can ask engine stop lower than threshold velocity or engine torque lower than the threshold value moment of torsion lower than threshold value, the speed of a motor vehicle in response to the expectation driveline torque.As another example, controller 12 can jam on vehicle brake pedal or the request engine stop in response to battery charging state (higher than threshold value) in response to chaufeur.Therefore, can carry out the engine stop request by the input that not only has this function of request engine stop.In other example, in response to satisfying following arbitrary idling-stopping condition, can automatically ask engine stop.For example, these conditions higher than threshold value (for example can comprise driving engine execution burning, battery charging state, higher than threshold value 30%), the speed of a motor vehicle higher than threshold value, do not carry out air-conditioning request, engine temperature higher than threshold value, emission control system temperature higher than threshold value (for example, higher than ignition temperature), chaufeur demand torque lower than threshold value, vehicle electrical loads lower than threshold value etc.If do not satisfy engine stop condition, in the situation that keep driving engine operation termination routine.That is, can not kill engine.

In case determine to satisfy engine stop condition, just in step 406, can determine whether to expect that the driving engine rolling stops (rolling stop).In an example, when not jamming on brake pedal and acceleration pedal and vehicle mobile, can expect and realize driving engine rolling parking or vehicle sliding.In another example, based on the indicative of desired time length till stopping fully to driving engine, can expect that carrying out the driving engine rolling stops.For example, can estimate the speed of a motor vehicle when satisfying engine stop condition and can determine that whether this speed of a motor vehicle is higher than threshold velocity.Threshold velocity can corresponding to be not enough to keep vehicle sliding vehicle inertia value for a long time, be about to occur vehicle and stagnate this moment.Therefore, rolling stops if the speed of a motor vehicle higher than threshold value, can be carried out driving engine, and this can provide fuel economy benefit.In another example, can roll and stop based on carrying out driving engine about the traffic of vehicle environment of living in and geography information (such as determining from Vehicular navigation system) expectation.For example, if vehicle travels in the frequent city that occurs starting and stopping, not expecting to carry out the driving engine rolling and stop.

If expectation is rolled stop, in step 408, can determine to roll stops moment of torsion error estimation condition.This can comprise definite: the speed of a motor vehicle is in higher than threshold value, change-speed box lower than the fuel height threshold value (so that electrical motor has enough torque capacities with respect to the negative torque that the rolling stopping period produces), vehicle fuel tank lower than threshold value (so that rolling stopping period regenerating braking energy can enter battery from motor), motor torque higher than minimum threshold velocity but lower than maximum threshold velocity, battery charging state (needed pick-off gear) in required gear etc. in addition, before can estimating the moment of torsion error.

Stop moment of torsion estimation condition if not satisfying rolls, in step 412, program comprises and optionally killing engine to driving engine feed fuels and igniting by stopping, and discharges the disconnect-type clutch that is connected between motor (such as electrical motor or CISG) in driving engine and vehicle driveline.Then, controller stops the driving engine rolling, but can not estimate the moment of torsion error after power-transfer clutch discharges at the rolling stopping period.In an example, can carry out DECEL ENLEAN (DFSO) operation to stop the fuel supply to driving engine, driving engine continues rotation simultaneously.Particularly, in case carry out the DFSO operation, just stop to cylinder injection fuel.Then, driving engine rotates gradually to static.

Stop moment of torsion estimation condition if satisfy to roll, in step 414, program comprises optionally and killing engine.In addition, can discharge the disconnect-type clutch that is connected between motor (such as electrical motor or CISG) in driving engine and vehicle driveline.Alternatively, for keeping the constant moment of torsion in wheel place, can increase motor torque.Describe in detail as Fig. 5 to Fig. 6, controller can be after disconnect-type clutch discharges (but stopping to driving engine feed fuels before) estimates the moment of torsion error based on the one or more deviations with respect to its designated value separately in power-transfer clutch point of release place engine torque, engine speed and engine acceleration/deceleration/decel.Each set point place in a plurality of engine speed setpoint can assess the engine speed response.

In addition, for example, can estimate the moment of torsion error with respect to the deviation of expectation curve based on each set point place's motor speed and the motor acceleration of a plurality of engine speed setpoint.In an example, machine is CISG.In another example, machine is the electrical motor in the hybrid electric vehicle power driving system.In addition, describe in detail as Fig. 5 to Fig. 6, estimation error can driving engine be set (such as engine speed) and actuator and is set the function of (such as flow regulating valve angle, supercharging value, cam timing, valve timing etc.) and obtain.The error that obtains can be used for upgrading the moment of torsion appraising model.

Return to step 406, if not expecting to roll stops, in step 410, can determine that non-rolling stops moment of torsion error estimation condition.These conditions can comprise definite restarting of not expecting or ask to change mind.If the expectation chaufeur is changed mind restart, can not carry out the moment of torsion error estimation that adopts Fig. 6 method.Thus, if chaufeur is changed mind and after engine stop-state immediately the request restart, controller can be configured to not carry out the engine torque error estimation (perhaps, restart if change mind during the moment of torsion error estimation, stop immediately) and accelerate driving engine is stopped fully, to change mind in response to chaufeur and to accelerate follow-up engine restarting process.

Do not stop moment of torsion estimation condition if do not satisfy non-rolling, program proceeds to step 412.At this, program comprises by stopping to driving engine feed fuels and igniting and optionally kills engine and discharge the disconnect-type clutch that is connected between motor (such as electrical motor or CISG) in driving engine and vehicle driveline.Then, controller can make the non-rolling of driving engine stop (for example, stopping fast), but at non-rolling stopping period, does not estimate the moment of torsion error process after power-transfer clutch discharges.

Stop moment of torsion estimation condition if satisfy non-rolling, program proceeds to the step 414 that selectivity kills engine.In addition, can discharge the disconnect-type clutch that connects between motor (such as electrical motor or CISG) in driving engine and vehicle driveline.Alternatively, for keeping the constant moment of torsion in wheel place, can improve motor torque.Describe in detail as Fig. 5 to Fig. 6, controller can be estimated the moment of torsion error based on the one or more deviations with respect to its designated value separately in engine torque, engine speed and the engine acceleration/deceleration/decel at power-transfer clutch point of release place after disconnect-type clutch discharges.Particularly, controller can be estimated the moment of torsion error with respect to the deviation of given engine speed curve based on the practical engine speeds curve at each set point place of a plurality of engine speed setpoint.

Thus, the quantity of the engine speed setpoint of research engine speed response can be to roll that to stop be also that non-rolling stops and different based on engine stop.Particularly, the rolling of driving engine experience is the more engine speed setpoint of moment of torsion error evaluation (due to until the relatively long time length of the complete static meeting experience of driving engine) when stopping, and is the less engine speed setpoint of moment of torsion error evaluation (due to until relatively short time length is experienced in the complete static meeting of driving engine) when the non-rolling of driving engine experience stops.

Program proceeds to step 416 from step 414, and method 400 judges whether to satisfy the engine restarting condition and whether expects start the engine.Can ask engine starting by operated key or key-press input with unique function of asking engine starting.Alternatively, can automatically ask engine restarting based on running state by controller 12.For example, controller 12 can discharge vehicle brake pedal or in response to battery charging state request engine starting in response to chaufeur.Therefore, can ask to restart driving engine by the input that not only has this function of request engine starting.If driving engine is restarted in method 400 judgement requests, method 400 proceeds to step 420.Otherwise method 400 proceeds to keeps engine off state (or idle stop state) until satisfy the step 418 of engine restarting condition.

In step 420, in response to satisfying the engine restarting condition, can optionally restart driving engine (for example, lighting a fire and the fuel supply by recovery).In certain embodiments, driving engine can be at the starter auxiliary lower rotating crank of (such as for have the starter of low moment of torsion output compared to CISG).In another example, driving engine can start via CISG, and has the starter maintenance closed condition of low torque capacity.In case restart driving engine, just can use disconnect-type clutch.In addition, when using power-transfer clutch or be right after before using power-transfer clutch, can specify engine torque to realize a smooth transition, wherein, the engine torque designated value is based on the moment of torsion appraising model of the moment of torsion error that obtains and renewal.

In this way, can obtain the moment of torsion estimation error, make the moment of torsion error reduce in time.This especially can improve moment of torsion control during the disconnect-type clutch in using and discharging the hybrid electric vehicle power driving system.

Referring now to Fig. 5, show during engine off after disconnect-type clutch discharges the method 500 based on engine speed and acceleration bias acquisition moment of torsion estimation error.The method of Fig. 5 can be used as the part (such as in step 414) of method shown in Figure 4.Detailed description shown in Figure 7 obtains the exemplary curve of moment of torsion error via the method for Fig. 5.

In step 501, the method comprises that determining whether to ask driving engine to roll stops.Thus, the method for Fig. 5 is only carried out at driving engine rolling stopping period.In case after confirming, the method just comprises in step 502 attempts to provide zero moment of torsion at disconnect-type clutch two ends (power-transfer clutch discharge after), disconnect-type clutch with engine mechanical be connected to motor.In an example, this program comprises that determining after power-transfer clutch discharges to provide at disconnect-type clutch two ends is the engine torque designated value of zero moment of torsion substantially, and the method also is included in to be right after during engine stop-state specified determined moment of torsion designated value before power-transfer clutch discharges.

Next, in step 504, this program comprises and optionally kills engine and reduce disconnect-type clutch capacity (to discharge gradually disconnect-type clutch) in engine retard, keeps simultaneously determined engine torque designated value.Next, in step 506, can confirm that disconnect-type clutch discharges.For example, the clutch capacity that can confirm disconnect-type clutch is lower than threshold value or be minimum capacity.After confirming that disconnect-type clutch has discharged, in step 508, the method comprises in power-transfer clutch discharges a period of time of beginning one or more in estimating engine rotating speed, engine acceleration/deceleration/decel and motor speed and motor acceleration/deceleration/decel.

In step 510, can determine that self-separation formula power-transfer clutch discharges engine speed, engine acceleration/deceleration/decel and motor speed and the motor acceleration/deceleration/decel of expecting in a period of time of beginning based on the engine torque of appointment.In an example, after disconnect-type clutch discharges, can select determined engine torque designated value, thereby make engine retard or have the engine speed response of expectation with the moderating ratio of expectation.Similarly, after disconnect-type clutch discharges, can select determined engine torque designated value, thereby machine speed curve or the rate of acceleration of expectation are provided.

In step 512, the engine speed of reality and machine speed response (estimate in step 508 and obtain) are compared with expectation value (definite in step 510).If actual value and expectation value coupling, in step 514, can determine does not have the engine torque error.On the other hand, if actual value and expectation value are not mated, in step 516, this program is determined the engine torque error based on actual value with respect to the deviation of estimated value.Particularly, engine controller is estimated disconnect-type clutch moment of torsion error discharge after with respect to its expectation value or deviation of designated value separately based on one or more in engine speed, engine acceleration/deceleration/decel, machine speed, machine acceleration/deceleration and engine torque when power-transfer clutch discharges.Speed responsive based on driving engine and/or motor when in this way, this program is included in disconnect-type clutch release obtains the engine torque error.

Controller can based on the directivity of deviation determine estimation error be whether due to engine torque cross estimation or low estimation causes.In an example, comprise based on engine speed response acquisition moment of torsion error: the actual deceleration rate based on the driving engine that is slowing down is come estimating engine moment of torsion error with respect to the deviation of expectation moderating ratio.Thus, if keep the engine torque designated value after disconnect-type clutch discharges, and if this moment of torsion designated value is rightly corresponding to the zero moment of torsion on disconnect-type clutch, after power-transfer clutch discharges, motor speed should be kept constant (or being in the scope of its previous rotating speed, in the scope that is in 10RPM), before discharging from power-transfer clutch simultaneously, driving engine should be kept its current rotating speed or slow down with a certain constant low rate.Therefore, after discharging in response to power-transfer clutch, the variation of the variation of machine speed and engine speed or moderating ratio (before discharging compared to power-transfer clutch), can determine the engine torque error.This procurement process can also comprise: if driving engine obtains engine torque and crosses estimation error with slow down lower than the mode of expectation moderating ratio (perhaps engine speed is higher than the expectation rotating speed); And if driving engine obtains the low estimation of engine torque error with slow down higher than the mode of expectation moderating ratio (perhaps engine speed is lower than the expectation rotating speed).

In step 518, the moment of torsion error can driving engine be set and the function of actuator setting obtains.For example, the moment of torsion error can be used as the function of engine speed.As another example, the moment of torsion error can be used as the function of flow regulating valve angle, valve timing, spark timing, cam timing, supercharging value, manifold air-flow etc.In an example, the error in the renewable look-up table of controller, this look-up table stores is as the estimation moment of torsion error of the function of driving engine and actuator setting.

In step 520, this program comprises uses the moment of torsion error update engine torque appraising model that obtains.This allows to improve moment of torsion and controls during follow-up power operation.For example, in follow-up engine restarting operating period, controller can based on the engine torque appraising model that upgrades control restart during the moment of torsion error of appointment.Particularly, during follow-up engine restarting, can send moment of torsion designated value more accurately when using disconnect-type clutch.

As an example, during the engine off state, the disconnect-type clutch between the motor of controller releasable connection in driving engine and vehicle driveline.Motor can or be other electrical motor for CISG, and this motor is connected to change-speed box and wheel in vehicle driveline with driving engine.Before discharging disconnect-type clutch, controller can be specified the engine torque of keeping expectation engine retard degree.Then, the one or more engine operation parameters of controller capable of regulating are kept the engine torque of appointment.Subsequently, can discharge disconnect-type clutch.After discharging disconnect-type clutch, controller can be determined the moment of torsion estimation error with respect to the deviation of expectation engine retard degree based on the real engine deceleration/decel, keeps simultaneously the engine torque of appointment.

In this way, after disconnect-type clutch discharged, the engine speed after can discharging based on power-transfer clutch during engine off obtained the moment of torsion error, and driving engine keeps rotation simultaneously.Also use as the moment of torsion error of the function of driving engine setting the error that obtains by acquisition, provide more accurately moment of torsion to control during follow-up power operation, can reduce use and releasing clutch during the power drive system disturbance increase and can realize transition more stably.

Fig. 7 shows and uses the example that obtains the moment of torsion error during the engine off state of the described method of Fig. 5 in hybrid vehicle.Particularly, accompanying drawing 700 shows the variation of engine speed with curve 702, show the variation of engine torque with curve 704, shows the variation of disconnect-type clutch capacity with curve 706.Before t1, driving engine can use the engine torque operation based on the appointment of operation torque demand (for example, based on pedal position).Thus, during this period of time, can provide at least part of required torque by driving engine.For example, can satisfy all torsion torque demand by driving engine.Alternatively, can satisfy all torsion torque demand by driving engine and system battery.

At the t1 place, can confirm engine stop-state.For example, can confirm idle stop state.Therefore, at the t1 place, engine torque can be appointed as (curve 704, solid line) can provide at the disconnect-type clutch two ends is zero moment of torsion substantially, this disconnect-type clutch is connected to the motor of rotation with the engine mechanical of rotation, and is thus connected to vehicle driveline change-speed box and wheel.The engine torque of appointment can be defined as expecting the function of engine acceleration (perhaps being in this case deceleration/decel) and driving engine inertia.Between t1 and t2, the one or more engine operation parameters of engine controller capable of regulating are so that the engine torque (curve 704, solid line) of the more approaching expectation/appointment of engine torque (curve 705, dotted line) of estimation.

At the t2 place, the engine torque of estimation can be set as near target torque.Therefore, at the t2 place, controller can begin to reduce the clutch capacity (curve 706) of disconnect-type clutch with releasing clutch, keeps simultaneously engine torque designated value (curve 704) constant.Thus, it is that the engine torque designated value of zero (being positioned near the threshold range zero) and (for example, being right after before discharging) before power-transfer clutch discharges specifies this moment of torsion designated value of determining to discharge at power-transfer clutch to provide zero moment of torsion for disconnect-type clutch afterwards substantially that controller is attempted by determining to provide.

Thus, if the engine torque designated value that transmits is correct, discharging the rear engine rotating speed at power-transfer clutch can not change (namely substantially, there is no the velocity variations higher than threshold value, for example, than the high 10rpm of speed before), and driving engine can with before discharging with power-transfer clutch (namely, along curve 702) substantially similar mode (that is, with similar little speed) continuation acceleration or deceleration.Yet if there is error in the moment of torsion estimated value, and there is error in the moment of torsion of therefore appointment, and the engine speed response meeting after power-transfer clutch discharges departs from respect to expectation value.

At the t3 place, clutch capacity can be decreased to minimum capacity.In case clutch capacity descends and disconnect-type clutch is released, engine controller can be in power-transfer clutch discharges a period of time of beginning (that is, the time period between t3 and t4) monitoring and estimating engine parameter.The parameter of estimating within the time period that limits can comprise driving engine average acceleration (accel_ave), driving engine mean speed (rpm_ave) and the average estimated value of engine torque (tq_ave).Then, can to calculate and obtain engine torque error (tq_error) as follows for controller:

The tq_error=tq_ave-accel_ave* engine inertia

In this way, a period of time intrinsic motivation after discharging based on power-transfer clutch and/or the velocity curve of motor, controller can obtain to provide the required air of zero moment of torsion and the error of fuel.

For example, obtain error based on engine speed graph and comprise: if a period of time intrinsic motivation actual speed curve higher than the engine speed graph of expectation, obtains to estimate corresponding error with the mistake of engine torque.Curve 708 (long and short dash line) shows exemplary moment of torsion and crosses estimation or cross the transmission error.As another example, obtain error based on the speed curves of driving engine and comprise: if a period of time intrinsic motivation actual speed curve lower than the engine speed graph of expectation, obtains the error corresponding with the low estimation of engine torque.Curve 709 (dotted line) shows the low estimation of exemplary moment of torsion or the low error that transmits.In each case, the engine speed graph of expectation is all based on engine torque designated value (curve 706).

The moment of torsion error can engine speed and the function set of one or more engine actuators obtain.For example, confirm a place in the moment of torsion error, one or more function that this error can be used as in flow regulating valve, EGR, supercharging value, MAF, MAP, cam timing and valve timing setting obtains.Then, the error of acquisition is used for upgrading the engine torque appraising model.Particularly, the engine torque appraising model can be estimated friction torque with many kinds of parameters, such as moment of torsion error, air pressure, oil temperature, driving engine mean speed etc.During engine restarting, the moment of torsion error of using in the moment of torsion appraising model can be upgraded with reference to the moment of torsion error that obtains during the engine off that is right after in front.

As previously mentioned, the described moment of torsion error of Fig. 5 and Fig. 7 preparation method can be carried out during driving engine rolls halted state.That is, as mentioned above, during the engine idle halted state, can obtain the moment of torsion error when the speed of a motor vehicle during higher than threshold velocity, discharge simultaneously disconnect-type clutch in the speed of a motor vehicle during higher than threshold velocity.

Referring now to Fig. 6, show after discharging based on disconnect-type clutch during engine off the illustrative methods 600 that engine speed and acceleration bias at selected engine speed setpoint place obtain the moment of torsion estimation error.The method of Fig. 6 can be used as the part of the program of Fig. 4, such as step 414.Describing the exemplary curve that obtains the moment of torsion error by the method for Fig. 6 shown in Fig. 7 and Fig. 8 in detail.Should be appreciated that after discharging disconnect-type clutch and stopping to engine oil with before killing engine, the execution following methods obtains the moment of torsion error.

In step 602, the method comprises and determines whether to require or the expectation driving engine rolls and stops.As before in Fig. 4 (step 406) describe in detail, when requiring engine off, can determine that driving engine rolls based at least one pedal position and the speed of a motor vehicle (with respect to threshold value) and stop, and itself and the non-rolling of driving engine stop existing difference.If confirm that the driving engine rolling stops, this program proceeds to step 604.Otherwise program proceeds to step 606 to determine whether need to or expecting that the non-rolling of driving engine stops.If determine that the non-rolling of driving engine stops, program proceeds to step 608.Thus, the method 600 of Fig. 6 can be carried out at roll stopping period and the non-rolling stopping period of driving engine of driving engine, yet the quantity that monitoring and assessment driving engine and/or motor speed respond to obtain the engine speed setpoint of torque deviation can change based on the character of engine stop.

In step 604 and step 608, selected a plurality ofly will be used for the engine speed setpoint of definite moment of torsion estimation error.In both cases, can select a plurality of engine speed setpoint based on the engine torque error history.For example, can be based on the passing Information Selection engine speed setpoint relevant to engine torque transmission error in the memory device that is stored in controller.Can based on the engine acceleration data and/or based on use and discharge disconnect-type clutch during and the power drive system disturbance experienced afterwards to transmit error at those selected engine speed setpoint place's indication engine torques.

As implied above, driving engine rolls and stops stopping comparing with the non-rolling of driving engine, and the quantity of engine speed setpoint can be different.Particularly, in step 604, when driving engine slides into when static (, for driving engine rolling halted state), select more engine speed setpoint during the engine off state; And in step 608, when stopping (such as for the non-rolling halted state of driving engine), can select less engine speed setpoint when driving engine quick (that is, basically immediately).At this, based on the quantity that reaches the static expected duration of driving engine during the engine off state and select engine speed setpoint, the quantity of selected engine speed setpoint reaches the increase of static expected duration along with driving engine and increases (situation about stopping as rolling).In another example, the increase of the difference between the engine speed the when engine speed the when quantity that obtains the engine speed setpoint of error can discharge along with power-transfer clutch and driving engine static (, speed is zero) increases.

Program proceeds to step 610 from step 604 and step 608, determines the error estimation window based on the selected engine speed setpoint with torque disturbances history.This window can corresponding to the rotating speed window around selected engine speed setpoint, be carried out error estimation based on the driving engine in these windows (or machine) rotating speed response.Next, in step 612, can determine that when power-transfer clutch discharges for disconnect-type clutch provides be the engine torque designated value of zero moment of torsion substantially, this power-transfer clutch is connected to engine mechanical change-speed box and the wheel of motor and vehicle driveline.Determined engine torque designated value can be specified before power-transfer clutch discharges, and particularly, was right after before power-transfer clutch discharges and specified.In an example, after disconnect-type clutch discharged, determined engine torque designated value can be relevant to engine speed response or the engine speed graph of expectation.Similarly, after disconnect-type clutch discharged, determined engine torque designated value can respond or the machine rotational speed curvilinear correlation with the machine rotational speed of expectation.

Next, in step 614, can confirm whether disconnect-type clutch discharges.For example, the clutch capacity that can confirm disconnect-type clutch is lower than threshold capacity or be minimum capacity.After confirming that disconnect-type clutch has discharged, in step 616, the method is included in engine speed graph and the engine acceleration/projectile deceleration history of determining each selected engine speed setpoint of estimation in window place.Alternatively, can also be in determining window motor speed curve and the motor acceleration/projectile deceleration history at each selected engine speed setpoint of estimation place.Except engine speed response, can also estimate and determine the actuator setting at each selectes engine speed setpoint place in determining window.

In step 618, can determine desired engine speed curve and the engine acceleration/projectile deceleration history at each selected engine speed setpoint place.Alternatively, can also determine for each selected engine speed setpoint motor speed curve and the motor acceleration/projectile deceleration history of expectation.In an example, the engine speed graph of expectation can be based on the hypothesis of indication zero moment of torsion (step 612).For example, after disconnect-type clutch discharges, can select the engine torque designated value to make the driving engine acceleration/deceleration with the speed of expectation or engine speed with expectation responds.Similarly, after disconnect-type clutch discharges, can select the engine torque designated value determined, so that machine rotational speed curve or the acceleration/accel of expectation to be provided.

In step 620, actual engine speed can be responded/curve and machine speed response/curve (estimate in step 616 and obtain) compare with expectation value (determining in step 618).If actual value and expectation value are complementary, in step 622, can determine not exist the engine torque error.On the other hand, in step 624, if actual value and expectation value are not mated, this program is determined the engine torque error based on actual value with respect to the deviation of estimated value.Particularly, the moment of torsion error after controller discharges based on the Error estimation disconnect-type clutch of (or expectation) engine speed graph of the actual engine speed curve at each set point place of a plurality of engine speed setpoint and appointment.In this way, this program is included in disconnect-type clutch release and obtains the engine torque error based on the speed curves of driving engine and/or motor afterwards.

Should be appreciated that if do not satisfy moment of torsion error estimation condition (as what describe in detail in previous step 408 at Fig. 4 and step 410), do not carry out the moment of torsion error estimation.For example, if the fuel height in vehicle fuel tank lower than threshold value, controller can not estimated the moment of torsion error.As another example, expectation is restarted if chaufeur is changed mind, and can not carry out the moment of torsion error estimation of the method for using Fig. 6.In addition, if during estimating and obtaining the moment of torsion error, the expectation of chaufeur flip-flop idea is restarted, and can interrupt immediately estimation and procurement process to the moment of torsion error, makes driving engine accelerate to rotate to quiescence (restarting with boost engine) with Time Controller.

Controller can determine that whether institute's estimation error is because estimation is still hanged down in the estimation of crossing of engine torque based on the directivity of deviation.Thus, if discharging before specified moment of torsion, still keeps after power-transfer clutch discharges power-transfer clutch, and if the moment of torsion designated value is rightly corresponding to the moment of torsion that on disconnect-type clutch is substantially zero, after power-transfer clutch discharges, speed curves before engine speed graph should discharge with respect to power-transfer clutch remain unchanged (for example, in the threshold range such as 10RPM).Therefore, after discharging in response to power-transfer clutch, the change of engine speed graph (or engine acceleration), at specific rotation speeds set point place, can determine the engine torque error.Procurement process can further comprise: if the actual engine speed curve in the engine speed window obtains engine torque and crosses estimation error higher than the engine speed graph of expectation; If the actual engine speed curve in the engine speed window lower than the engine speed graph of expectation, obtains the low estimation of engine torque error.

As the example in detail of reference Fig. 8 to Fig. 9, the engine speed graph deviation that can carry out in many ways based on specified engine speed set point place obtains error.In a kind of method shown in Figure 8, but also can making closed loop controller adjust actuator, controller given engine speed target (corresponding to selected engine speed setpoint) sets engine speed is maintained the engine speed target.Then, can obtain torque model error and/or engine speed is maintained the required actuator of target velocity sets and change (from initial setting).Can repeat above-mentioned processing for each selected engine speed setpoint place.In alternative shown in Figure 9, level and smooth engine speed graph can be stipulated or specify to controller, and can be at selected specified engine speed set point place's collection engine speed, engine acceleration and engine torque (designated value and estimated value) while engine retard.Controller can make closed loop controller adjust the level and smooth engine speed graph that actuator sets to realize appointment.Then, can each target velocity set point the place obtain or gather the variation (from initial setting) that torque model error and/or actuator are set.

In step 626, can obtain the moment of torsion error and be stored as the function of the corresponding engine speed setpoint point of error (obtain moment of torsion).The moment of torsion error of estimation can be further used as the function that one or more actuators are set, and comprises flow regulating valve angle, spark timing, cam timing, supercharging value, manifold air-flow etc.In an example, the error in the renewable look-up table of controller, look-up table is stored as the moment of torsion error of estimation the function of driving engine and actuator setting.

In step 628, this program comprises the moment of torsion error update engine torque appraising model with the estimation that obtains.This allows to improve moment of torsion and controls during follow-up power operation.For example, in follow-up engine restarting operation, controller can be used disconnect-type clutch and adjust the engine air supply based on the moment of torsion error that obtains and supply with fuel during restarting, the engine torque of appointment when using power-transfer clutch to control.In this way, can transmit moment of torsion designated value more accurately during follow-up engine restarting, reduce the power drive system disturbance when using power-transfer clutch.The moment of torsion error that obtains can also be used for during the flame-out operation of follow-up tail-off is restarted adjusting that engine air is supplied with and the engine torque of fuel appointment when giving control clutch release.In this way, can transmit moment of torsion designated value more accurately during follow-up engine off, reduce the power drive system disturbance when power-transfer clutch discharges.

Fig. 8 shows the method for using Fig. 6 and obtain the first example of moment of torsion error at selected speed setpoint place during the engine off state of hybrid vehicle.Particularly, accompanying drawing 800 has been described the variation of motor speed with curve 802, described the variation of engine speed with curve 804, has described the variation of engine torque and has described the variation of disconnect-type clutch capacity with curve 808 with curve 806.Curve 805 (dotted line) shows expectation (discontinuous) engine speed graph with discrete engine speed setpoint, wherein estimates progressively the moment of torsion error at discrete set point place.Should be appreciated that after discharging disconnect-type clutch but stopping to the driving engine feed fuels carrying out follow-up method with acquisition moment of torsion error with before killing engine.

Before t1, can use the engine torque based on chaufeur torque demand (for example, based on pedal position) appointment to move driving engine.Thus, during during this period of time, can provide at least part of required torque by driving engine.For example, can satisfy all torsion torque demand by driving engine.Alternatively, can satisfy all torsion torque demand by driving engine and system battery.

At the t1 place, can determine engine stop-state.For example, can determine the engine idle halted state.Therefore, at the t1 place, can specify engine torque (curve 806).In an example, it is zero moment of torsion substantially that the engine torque of appointment can be realized providing at disconnect-type clutch two ends, this disconnect-type clutch is connected to the motor of rotation with the engine mechanical of rotation, and is connected to from here change-speed box and the wheel of vehicle driveline.The engine torque of appointment can be confirmed as the function of driving engine inertia, in order to can obtain specific engine speed graph (curve 805).Specific engine speed graph (curve 805) can be discontinuous engine speed graph, and it comprises that self-separation formula power-transfer clutch discharges the discrete target engine speed (810 to 813) that beginning obtains at specified time.Particularly, the target engine speed set point can obtain for self adaptation the speed setpoint of moment of torsion error.The target engine speed set point can be set or the power drive system disturbance based on the adjustable that experiences during the release disconnect-type clutch of previous power operation (or using disconnect-type clutch).In addition, at the t1 place, controller can begin to reduce the clutch capacity (curve 808) of disconnect-type clutch, to discharge disconnect-type clutch.Thus, in case discharged disconnect-type clutch, change-speed box just is in neutral gear position.

Thus, to attempt by determining to provide be that the engine torque designated value of zero moment of torsion and (being right after before discharging) before power-transfer clutch discharges specifies determined moment of torsion designated value to discharge at disconnect-type clutch to provide zero moment of torsion at disconnect-type clutch two ends afterwards to controller substantially.Thus, if the engine torque designated value that transmits is correct, the material alterations of engine speed or machine speed (curve 802) when discharging, power-transfer clutch should be unable to occur (for example, there is no the variation higher than threshold quantity, such as many 10RPM than preceding value), and driving engine can continue acceleration/deceleration with less and constant speed, the curve before wherein velocity curve discharges based on power-transfer clutch.Yet, if having error in the moment of torsion estimation, correspondingly there is error in specified moment of torsion, the engine speed response after power-transfer clutch discharges will depart from expectation value.

At the t2 place, can discharge engine clucht.Then, controller can be set the first expectation engine speed setpoint 810, realizes simultaneously closed loop control.Therefore, expectation provides to the engine torque designated value of engine speed setpoint 810 and can depart from the t2 place.Then, controller can wait for that engine speed is set as near expectation target engine speed setpoint (for example, in its threshold range).Similarly, controller waits for that also the actual engine torque designated value is set as near required torque (for example, in its threshold range).At the t3 place, after setting engine speed and moment of torsion, controller can estimate around the driving engine average acceleration (accel_ave) in the window of rotating speed of target set point, driving engine mean speed (rpm_ave) and estimate mean engine moment of torsion designated value (tq_ave).Particularly, can determine estimated value in by the window that limits around the t2 of first object speed setpoint 810 and the time period between t3.

Between t2 and t3, the one or more engine operation parameters of engine controller capable of regulating are to adjust engine torque and to make practical engine speeds more near the rotating speed of target set point.Then, controller can gather the real actuator setting of using by closed loop control in the window between t2 and t3, to keep engine speed and to make it arrive target engine speed set point 810.

At the t3 place, the engine torque error 820 (tq_error) that controller also calculates and obtains to occur at engine speed setpoint 810 places:

Tq_error ≡ tq_ave-accel_ave* driving engine inertia

In this way, controller can obtain moment of torsion error 820 at selected engine speed setpoint 810 places, comprises air supply error and fuel supply error.Controller can also obtain and upgrade the required actuator of engine speed of realizing and keeping engine speed setpoint 810 places and set.

Then, at the t3 place, controller can be set the second expectation engine speed setpoint 811 and continue simultaneously closed loop control.Correspondingly, expectation provides the engine torque designated value of engine speed setpoint 811 to depart from the t3 place.Then, controller can wait for that engine speed is set as near required target engine speed set point (for example, in its threshold range).Similarly, controller waits for that also the actual engine torque designated value is set as near required torque (for example, in its threshold range).At the t4 place, when setting engine speed and moment of torsion, controller can be in around the window of rotating speed of target set point estimating engine average acceleration (accel_ave), driving engine mean speed (rpm_ave) and the mean engine moment of torsion designated value (tq_ave) estimated.Particularly, can determine estimated value in the window that is limited by near the t3 first object speed setpoint 811 and the time period between t4.

Between t3 and t4, the one or more engine operation parameters of engine controller capable of regulating are to adjust engine torque and to make practical engine speeds more near the rotating speed of target set point.Then, controller can gather the real actuator setting of using by closed loop control in the window between t3 and t4, to keep engine speed and to make it reach target engine speed set point 811.At the t4 place, the engine torque error 821 (tq_error) that controller can further use above-mentioned equation to calculate and obtain to occur at engine speed setpoint 811 places.In this way, controller can obtain moment of torsion error 821 at selected engine speed setpoint 811 places, comprises air supply error and fuel supply error.Controller can also obtain and upgrade the required actuator of engine speed of realizing and keeping engine speed setpoint 811 places and set.

Controller can continue sequentially in the corresponding window of t4 to t5 and t5 to t6, and target setting

engine speed setpoint

812 and 813 also obtains corresponding moment of

torsion error

822 and 823.

For example, based in the engine speed window (namely, based on selected engine speed setpoint) the deviation of actual engine speed curve and driving engine expectation speed curves obtain error and comprise: if the practical engine speeds curve near the window selected engine speed setpoint higher than the engine speed graph of expectation, acquisition is estimated corresponding error with the mistake of engine torque.Similarly, if the practical engine speeds curve near the window selected engine speed setpoint lower than the engine speed graph of expectation, obtains the error corresponding with the low estimation of engine torque.

The function that the engine speed setpoint that the moment of torsion error can be corresponding and the one or more engine actuators that gather in corresponding window are set obtains.For example, error can the moment of torsion error confirm that the one or more function in a flow regulating valve at place, EGR, supercharging value, MAF, MAP, cam timing and valve timing setting obtains.In this way, the error of air supply and the fuel function that can be used as corresponding engine speed setpoint obtains.Then, the error of acquisition can be used for upgrading the engine torque appraising model.Particularly, the engine torque appraising model can be estimated friction torque with many kinds of parameters, such as moment of torsion error, air pressure, oil temperature, driving engine average velociity etc.The moment of torsion error of using in the moment of torsion appraising model during engine restarting can be upgraded with reference to the moment of torsion error that obtains during the engine off before the next-door neighbour.In this way, controller can be based on specified engine torque during the follow-up engine restarting of engine torque error control that obtains.

Fig. 9 shows the method for using Fig. 6 obtains to select the moment of torsion error at speed setpoint place during the engine off state of hybrid vehicle the second example.Particularly, accompanying drawing 900 has been described the variation of motor speed with curve 902, has described the variation of engine speed with curve 904 (solid line), has described the variation of engine torque and has described the variation of disconnect-type clutch capacity with curve 908 with curve 906.Curve 905 (dotted line) shows expectation with discrete engine speed setpoint (level and smooth and continuously) engine speed graph, wherein estimates progressively the moment of torsion error at discrete set point place.Should be appreciated that after disconnect-type clutch discharges but stopping to the driving engine feed fuels carrying out follow-up method with acquisition moment of torsion error with before killing engine.

Before t1, can be based on the engine torque operation driving engine of chaufeur torque demand (for example, based on pedal position) appointment.Thus, during this period of time, can provide at least part of required torque by driving engine.For example, can satisfy all torsion torque demand by driving engine.Alternatively, can satisfy all torsion torque demand by driving engine and system battery.

At the t1 place, can determine engine stop-state.For example, can determine the engine idle halted state.Therefore, at the t1 place, can specify engine torque (curve 906).In an example, it is zero moment of torsion substantially that the engine torque of appointment can provide at the disconnect-type clutch two ends, this disconnect-type clutch is connected to the motor of rotation with the engine mechanical of rotation, and is thus connected change-speed box and wheel to vehicle driveline.The engine torque of appointment can be confirmed as the function of driving engine inertia, in order to can obtain specific engine speed graph (curve 905).Specific engine speed graph (curve 905) can be level and smooth and continuous engine speed graph, and it comprises that self-separation formula power-transfer clutch discharges the discrete target engine speed set point (910 to 913) that beginning obtains at specified time.Particularly, the target engine speed set point can obtain for self adaptation the speed setpoint of moment of torsion error.Target engine speed set point 910 to 913 can discharge based on the disconnect-type clutch of previous power operation the adjustable that experiences during (or using power-transfer clutch) and sets or the power drive system disturbance.In addition, at the t1 place, controller can begin to reduce the clutch capacity (curve 908) of disconnect-type clutch, to discharge disconnect-type clutch.Thus, in case disconnect-type clutch discharges, change-speed box just is in neutral gear position.

Thus, to attempt by determining to provide be that the engine torque designated value of zero moment of torsion and (being right after before discharging) before power-transfer clutch discharges specifies determined moment of torsion designated value to discharge at power-transfer clutch to provide zero moment of torsion at disconnect-type clutch two ends afterwards to controller substantially.Thus, if the engine torque designated value that transmits is correct, material alterations should be unable to occur (for example, less than the variation greater than threshold velocity in engine speed when power-transfer clutch discharges.Such as the 10RPM greater than preceding value), and the speed that driving engine can be less and constant continues acceleration/deceleration, the curve before wherein velocity curve discharges based on power-transfer clutch.Yet, if having error in the moment of torsion estimation, correspondingly there is error in specifying moment of torsion, the engine speed graph after power-transfer clutch discharges will depart from expectation curve.

At the t2 place, can discharge engine clucht.Then, the engine speed graph that controller can be monitored expectation realizes closed loop control simultaneously, and selects self adaptation to obtain the first engine speed setpoint 910 of moment of torsion error.Then, controller can wait engine speed to be measured to be set as near target engine speed set point 910 (for example, in its threshold range).At the t3 place, when the actual engine speed curve has the speed setting that intersects with prescribed point 910, controller can near the window rotating speed of target set point 910 in estimating engine average acceleration (accel_ave), driving engine mean speed (rpm_ave) and the mean engine moment of torsion designated value (tq_ave) estimated.Particularly, can determine estimated value in the window that is limited by near the t2 first object speed setpoint 910 and the time period between t3.

Between t2 and t3, the one or more engine operation parameters of engine controller capable of regulating are to adjust engine torque and to make practical engine speeds more near the rotating speed of target set point.Then, controller can gather the real actuator setting that closed loop control is used in the window between t2 and t3, to keep engine speed or to make it reach target engine speed set point 910.

At the t3 place, controller can further calculate and obtain the engine torque error 920 of speed setpoint 910 places appearance so that practical engine speeds curve (curve 904) reaches the engine speed graph (curve 905) of expectation:

Tq_error ≡ tq_ave-accel_ave* driving engine inertia

In this way, controller can obtain moment of torsion error 920 at selected engine speed setpoint 910 places, comprises air and fuel error.Controller can also obtain and upgrade the required actuator of engine speed of realizing and keeping engine speed setpoint 910 places and set.

Between t3 and t4, controller can use closed loop control to continue the monitoring engine speed graph, waits for that simultaneously engine speed is near the second rotating speed of target set point 911.At the t4 place, when the actual engine speed curve has the speed setting that intersects with aforementioned speed setpoint 911, controller can near the window rotating speed of target set point 911 in estimating engine average acceleration (accel_ave), driving engine mean speed (rpm_ave) and the mean engine moment of torsion designated value (tq_ave) estimated.Particularly, can determine estimated value in the window that is limited by near the t3 first object speed setpoint 911 and the time period between t4.

Between t3 and t4, the one or more engine operation parameters of engine controller capable of regulating are to adjust engine torque and to make practical engine speeds more near the rotating speed of target set point.Then, controller can gather the real actuator setting that closed loop control is used in the window between t3 and t4, to keep engine speed or to make it reach target engine speed set point 911.Controller can further calculate and obtain the engine torque error 921 of speed setpoint 911 places appearance so that practical engine speeds curve (curve 904) reaches the engine speed graph (curve 905) of expectation.Controller can continue sequentially to monitor the engine speed graph deviation at selected target engine speed set

point

912 and 913 places and obtain corresponding moment of

torsion error

922 and 923 in the corresponding window of t4 to t5 and t5 to t6.

In this way, in response to idle stop state, controller can be released in the disconnect-type clutch that is connected between driving engine and motor (such as CISG), the while engine retard, but stopping before the engine spray fuel, controller can obtain the engine torque error in the engine speed window.In case power-transfer clutch discharges, just can be in the engine speed window expect the error that Error estimation obtains of speed curves based on actual engine speed curve and driving engine.For example, it is zero moment of torsion (by specify zero moment of torsion before power-transfer clutch discharges) substantially that controller is attempted when power-transfer clutch discharges to provide at disconnect-type clutch two ends, when engine retard, controller obtains to provide zero required air and the fuel error of moment of torsion based on the engine speed graph in the window of each set point of a plurality of engine speed setpoint simultaneously.As described in top example, controller can in engine speed setpoint 910 to the 913 places acquisition moment of torsion error 920 to 923 of correspondence, comprise air and fuel error.Controller can also obtain and upgrade the required actuator of engine speed of realizing and keeping corresponding engine speed setpoint place and set.

As previously mentioned, the described moment of torsion error of Fig. 6, Fig. 8 and Fig. 9 preparation method can be carried out under driving engine rolls stop condition and the non-rolling stop condition of driving engine, and wherein driving engine rolling stop condition is selected more engine speed setpoint compared to the non-rolling stop condition of driving engine.Thus, if driving engine rolling stopping period has obtained the moment of torsion error at different rotating speeds set point place, can discharge in the speed of a motor vehicle disconnect-type clutch during higher than the threshold value speed of a motor vehicle.

In this way, can be based on engine speed response acquisition moment of torsion estimation error after power-transfer clutch discharges, wherein power-transfer clutch is connected to driving engine the remainder of motor and vehicle driveline.By obtaining the moment of torsion error and upgrading the moment of torsion appraising model, can reduce the driveline torque disturbance of experiencing during application and releasing clutch.Control by improving moment of torsion, but the lifting vehicle driving performance.In addition, the method can reduce the power drive system wearing and tearing, thereby increases the work life of power drive system.

It will be appreciated by those skilled in the art that method as herein described can represent one or more in the processing policy of any amount, such as event-driven, drives interrupts, multitask, multithreading etc.Thus, the various actions that illustrate, operation or function can shown in order execution, executed in parallel or omit in some cases.Similarly, processing sequence not necessarily needs to realize target as herein described, function and advantage, but provides with description for convenience of explanation.Although do not offer some clarification on, those skilled in the art should recognize one or more can the repeating according to the specific policy that uses in described behavior and function.

In this summary description.Those skilled in the art can expect much substituting and retrofiting and do not depart from purport and the scope of this explanation after reading explanation.For example, can make a profit with the present invention with I3, I4, I5, v6, v8, V10 and the V12 driving engine of natural fuels, gasoline, diesel oil or the operation of alternative fuel device.

Claims

1. method that is used for hybrid vehicle comprises:

During the engine off state,

The disconnect-type clutch of release connection between the motor of driving engine and power transmission system of vehicle; And

When discharging, power-transfer clutch estimates described disconnect-type clutch moment of torsion error discharge after with respect to the deviation of separately designated value based on one or more in engine torque, engine speed and engine retard degree.

2. method according to claim 1, wherein, described motor is the bent axle (CISG) of integrated actuating machine/electrical generator, described CISG is connected to described driving engine change-speed box and the wheel of described power transmission system of vehicle.

3. method according to claim 1, wherein, the moment of torsion error of estimation is stored as the function of engine speed, and after discharging described disconnect-type clutch and stopping the moment of torsion error of the described estimation of acquisition before the described engine spray fuel.

4. method according to claim 1, also comprise: the moment of torsion error update engine torque appraising model that uses described estimation.

5. method according to claim 4, also comprise: based on the engine torque appraising model that upgrades, control described driving engine during follow-up engine restarting.

6. method according to claim 1, wherein, estimate that described moment of torsion error comprises:

Before discharging described disconnect-type clutch,

The engine torque of expectation engine retard degree is kept in appointment; And

Adjust one or more engine operation parameters to keep the engine torque of appointment; And

After discharging described disconnect-type clutch,

When keeping the engine torque of described appointment, determine described moment of torsion error based on the real engine deceleration/decel with respect to the deviation of described expectation engine retard degree.

7. method that is used for the hybrid electric vehicle power transmission system comprises:

In response to idling-stopping condition,

Optionally stop using driving engine and the disconnect-type clutch of release connection between driving engine and CISG, described CISG is connected to change-speed box and the wheel of Power Train; And

In described engine retard,

Keep the engine torque designated value; And

The rotating speed response of the described driving engine after discharging based on described disconnect-type clutch obtains the engine torque error.

8. method according to claim 7 wherein, selects described engine torque designated value so that the moment of torsion as zero to be provided at described disconnect-type clutch two ends substantially.

9. method according to claim 7, wherein, select described engine torque designated value, thereby the moderating ratio with expectation makes described engine retard after discharging described disconnect-type clutch.

10. method according to claim 9, wherein, the described engine torque error of described rotating speed response acquisition based on described driving engine comprises: the actual deceleration rate based on the driving engine that is slowing down is estimated described engine torque error with respect to the deviation of expectation moderating ratio.