DE102008039588B4 - Hybrid machine control system and method for controlling the same - Google Patents

Abstract

A hybrid engine control system, comprising: a hybrid engine control module (240) selectively stopping an internal combustion engine (102) and selectively starting the engine (102) based on driver inputs and non-driver inputs; and a torque mitigation module (250) that reduces torque transfer from the internal combustion engine (102) to a driveline (106) while starting the engine (102) based on non-driver inputs and transmitting torque from the internal combustion engine (102 ) to the driveline (106) while the engine (102) is being started based on the driver inputs.

Description

TERRITORY

The present disclosure relates to hybrid vehicles and, more particularly, to smoothing non-driver commanded engine re-launches in hybrid vehicles.

BACKGROUND

Now on the basis of 1 1 is a functional block diagram of a hybrid powertrain of a vehicle. A machine 102 delivers to a transmission 104 a torque. The gear 104 transmits the torque to a driveline 106 , It also drives the machine 102 a system of a belt-driven starter generator (BAS system) 110 and is powered by it. BAS systems can be characterized by a combination motor / generator used in place of a standard alternator and an accessory drive belt with the machine's crankshaft 102 connected is.

The BAS 110 puts power from the machine 102 into electrical power around in the charge storage 112 can be stored. When the machine 102 not running, the BAS can 110 Power from the charge storage 112 use the crankshaft of the machine 102 to drive and thereby drive the vehicle. The BAS 110 and the machine 102 are controlled by a hybrid engine control module (ECM) 120 controlled. The hybrid ECM 120 receives signals from driver input 122 such as an accelerator pedal, a gear shift lever and / or a brake pedal.

When the vehicle comes to a stop, the hybrid ECM 120 the machine 102 instruct to switch off. For example, this can be accomplished by providing fuel delivery and spark to the engine 102 be stopped. If the driver wishes to start the vehicle from stopping, as indicated by raising his or her foot from the brake pedal or pressing the accelerator pedal, the hybrid ECM may 120 the machine 102 instruct to restart. In addition, the machine can 102 through the ECM 120 for reasons not initiated by the driver to start instructed. When the machine 102 Restarts, a torque from the machine 102 over the transmission 104 to the final drive 106 transfer. If during the start of the machine 102 The brakes are applied, the driveline can 106 do not turn and torque is transmitted directly to the frame of the vehicle, which will be experienced by the driver as a jerk. Accordingly, in the publications EP 1 762 452 A2 and US 2007/0102211 A1 each proposed a method in which in the context of initiated by the driver and not by the driver machine starts the torque transmission to the driveline is reduced.

SUMMARY

Based on this prior art, a hybrid machine control system with the feature of claim 1 and a method having the feature of claim 10 are proposed according to the invention.

The hybrid engine control system includes a hybrid engine control module and a torque mitigation module. The hybrid engine control module selectively stops an internal combustion engine (ICE). The hybrid engine control module selectively starts the ICE based on driver inputs and non-driver inputs. The torque mitigation module reduces torque transfer from the ICE to a driveline while starting the ICE based on non-driver inputs and maintains torque transfer from the ICE to the driveline while starting the ICE based on the driver inputs.

In other features, the torque mitigating module reduces torque transfer by commanding a reduced hydraulic pressure from a pump in a transmission. The reduced hydraulic pressure is a function of the transmission oil temperature. The pump is powered by a charge storage module. The torque mitigation module reduces torque transfer by disengaging an electronically controlled clutch in a transmission.

In other features, the torque mitigation module reduces torque transmission by selecting a higher gear in a transmission. The non-driver inputs contain a low charge state of a charge storage module. The non-driver inputs include a demand signal from a heating, ventilation and air conditioning module. The driver inputs include signals from an accelerator pedal and a brake pedal.

The method includes selectively stopping an internal combustion engine (ICE); optionally starting the ICE based on driver inputs and non-driver inputs; reducing torque transfer from the ICE to a driveline while starting the ICE based on non-driver input; and maintaining torque transfer from the ICE to the driveline while the ICE is started based on the driver input.

In further features, reducing the torque transfer includes commanding a reduced hydraulic pressure from a pump in a transmission. The reduced hydraulic pressure is a function of the transmission oil temperature. Reducing torque transfer includes disengaging an electronically controlled clutch in a transmission.

In other features, reducing torque transmission includes selecting a higher gear in a transmission. The non-driver inputs contain a low charge state of a charge control module. The non-driver inputs include a demand signal from a heating, ventilation and air conditioning module. The driver inputs include signals from an accelerator pedal and a brake pedal.

BRIEF DESCRIPTION OF THE DRAWINGS

The present disclosure will become more fully understood from the detailed description and the accompanying drawings, in which:

1 FIG. 4 is a functional block diagram of a hybrid powertrain of a vehicle according to the prior art; FIG.

2A FIG. 4 is a functional block diagram of an exemplary hybrid powertrain according to the principles of the present disclosure; FIG.

2 B FIG. 10 is a functional block diagram of another exemplary hybrid powertrain according to the principles of the present disclosure; FIG.

3 FIG. 10 is a graphical representation of auxiliary oil pressure commands during a non-driver commanded engine restart according to the principles of the present disclosure; FIG.

4A FIG. 10 is a flowchart showing exemplary steps involved in controlling the hybrid powertrain. FIG 2A according to the principles of the present disclosure; and

4B FIG. 10 is a flowchart showing exemplary steps involved in controlling the hybrid powertrain. FIG 2 B according to the principles of the present disclosure.

DETAILED DESCRIPTION

For the sake of clarity, the same reference numerals will be used in the drawings to identify similar elements. As used herein, the term at least one of A, B, and C is intended to mean a logical (A or B or C) using a non-exclusive logical or. Of course, steps within a method may be performed in a different order without changing the principles of the present disclosure.

As used herein, the term module refers to an application specific integrated circuit (ASIC), to an electronic circuit, to a processor (shared, dedicated or group) and to memories that execute one or more software or firmware programs. to a combination logic circuit and / or other suitable components that provide the described functionality.

Now on the basis of 2A 1 is a functional block diagram of an exemplary hybrid powertrain. The machine 102 transmits torque to a gearbox 202 that drives the torque to the driveline 106 transfers. The gear 202 can be a torque converter 204 included, the torque from the machine 102 receives and torque with a gear set 206 coupled.

The gear set 206 transmits the torque to the final drive 106 , The gear 202 contains an oil pump 210 by entering in the torque converter 204 can be driven. In addition, the gearbox contains 202 an additional pump 212 passing through a charge storage module 216 can be supplied with power. The auxiliary pump 212 and the oil pump 210 provide hydraulic power to friction devices 220 of the transmission 202 ,

For example only, the friction devices 220 Clutches and / or brake bands included. The friction devices 220 control which gear ratio in the gear set 206 is selected. For example only, the gear set 206 to be a planetary gear set. The friction devices 220 can control which components of the gear set 206 with each other, with a housing of the gear set 206 and / or with the input or with the output of the gear set 206 are locked. This controls the gear ratio of the gear set 206 ,

The belt-driven starter generator (BAS) 110 puts power from the machine 102 into electrical power in the charge storage module 216 can be stored. In addition, the BAS 110 the crankshaft of the machine 102 drive to propel the vehicle when the machine 102 not running. The BAS 110 and the machine 102 can be coupled via a front accessory drive belt (FEAD belt).

The FEAD belt can also have an air conditioning compressor (A / C compressor) 230 drive. A heating, ventilation and air conditioning control module (HVAC control module) 232 controls the A / C compressor 230 , The HVAC control module 232 may control a blower motor for blowing conditioned air into the passenger compartment of the vehicle and may be at a temperature of the machine 102 and / or engine coolant. The HVAC control module 232 can be the A / C compressor 230 use to supply cooled and / or dehumidified air, and can remove heat from the machine 102 use to supply heated air.

A hybrid engine control module (ECM) 240 controls the machine 102 and the BAS 110 , When the vehicle comes to a stop, the hybrid ECM 240 the machine 102 such as stopping the supply of fuel and the spark to the engine 102 instruct to switch off. If the driver wants to start the vehicle from the stop, as by the driver inputs 122 can be specified, the hybrid ECM 240 the machine 102 instruct to restart. This is called a driver-commanded engine restart.

The auxiliary pump 212 Used to pump oil to supply hydraulic pressure to the gearbox 202 to deliver when the machine 102 not running. If the vehicle conditions such as zero vehicle speed, applied brake and accelerator pedal position allow zero, the hybrid ECM can 240 the machine 102 instruct to switch off. The hybrid ECM 240 can the machine 102 instruct to improve fuel economy. When the speed of the machine 102 falls below a threshold, the hybrid ECM 240 the auxiliary pump 212 instruct and instruct to generate a predetermined increased pressure.

The increased auxiliary pump pressure minimizes pressure losses during the transition between the pressure generated by the mechanically driven oil pump 210 and that supplied by the electrically powered booster pump 212 is delivered. After switching off the machine 102 has started, the auxiliary pump 212 instructed to generate a steady state pressure that is less than the increased pressure. This transition can occur when the machine 102 to stop spinning. When the machine 102 is restarted and reaches a certain RPM, the pressure of the auxiliary pump 212 can be reduced to zero and can the booster pump 212 be switched off.

While the machine 102 can be turned off, the hybrid ECM 240 the state of charge of the charge storage module 216 measure up. If the state of charge of the charge storage module 216 below a threshold level, the hybrid ECM 240 the machine 102 instruct to restart. This is an example of a non-driver instructed engine restart.

Another possible example of a non-driver-instructed engine restart is when the HVAC control module 232 the machine 102 request to restart. For example, the HVAC control module 232 require that in the machine 102 More heat is generated to deliver heated air. The HVAC control module 232 may require the A / C compressor 230 is powered to deliver cooled and / or dehumidified air.

When the machine 102 Restarts, can do that over the gearbox 202 to the final drive 106 transmitted torque can be absorbed by the frame of the vehicle, since the wheels of the final drive 106 do not turn. This can be experienced by the driver as a jolt or as a shock. This jolt can be experienced by the driver during a driver-ordered engine restart. However, a non-driver-commanded engine restart may be unexpected to the driver and experienced as a quality issue.

To soften the feeling of the jolt, the hybrid ECM 240 a torque attenuation module 250 instruct the amount of through the gear 202 with the final drive 106 reduce coupled torque. To the torque transmission through the gearbox 202 can reduce the torque attenuation module 250 the friction devices 220 temporarily slip and / or the gear set 206 temporarily select a lower gear ratio.

The torque attenuation module 250 can the auxiliary pump 212 instruct the hydraulic line pressure to decrease while the machine is restarted in response to a non-driver commanded restart. At a lower line pressure, the friction devices become 220 not fully engaged and allow slippage of the components of the gear set 206 to. The selected lower line pressure may be a function of transmission oil temperature. For example, the friction devices 220 a multi-plate oil bath clutch whose capacity is affected by the oil viscosity, which is a function of temperature. Also, the lower line pressure can prevent that from happening Hydraulic piston is fully engaged with a brake band.

When the machine has been restarted, the pressure exits from the oil pump 210 in the foreground and can the auxiliary pump 212 be switched off. When the game in the final drive 106 by the torque attenuation module 250 generated gradual torque transmission has been recorded, the friction devices 220 can be operated at full pressure and can the gear set 206 be reset to the desired gear.

In addition, the torque mitigation module 250 the gear set 206 temporarily select a lower gear ratio to command the transmission of torque through the transmission 202 to reduce. For example, instead of a speed reduction of the first gear from 3.06 to 1, a smooth gear ratio of 0.70 to 1 may be selected. By reducing the gear ratio, the torque mitigating module decreases 250 that to the final drive 106 transmitted torque. When the machine 102 restarted, the gear set may return to the first gear ratio of 3.06: 1.

Now on the basis of 2 B 1 is a functional block diagram of another exemplary hybrid powertrain. A gearbox 260 contains the torque converter 204 , the gear set 206 and the friction devices 220 , The oil pump 210 and the auxiliary pump 212 provide hydraulic power to the friction devices 220 ,

An electronically controlled clutch 262 Optionally couples the gear set 206 with the torque converter 204 , Alternatively, the electronically controlled clutch 262 the gear set 206 optionally with the final drive 106 couple. The electronically controlled clutch 262 is through a torque attenuation module 270 controlled.

If the hybrid ECM 240 a non-driver-instructed engine restart begins, the torque attenuation module 270 the electronically controlled clutch 262 deactivate. This decouples the torque converter 204 from the final drive 106 , After a predetermined delay, during which the machine 102 restarts, the torque mitigation module can 270 the electronically controlled clutch 262 engage again. In addition, the torque mitigation module 270 during this predetermined deceleration, a lower gear ratio in the gear set 206 choose.

Now on the basis of 3 FIG. 12 is a graphical representation of auxiliary oil pump pressure commands during a non-driver commanded engine restart. FIG. The graphic representation 302 shows the engine speed in revolutions per minute (RPM) as a function of time. The graphic representation 304 using the same time scale shows that of the booster pump 212 out 2A instructed pressure. In the graph 302 At first, the engine RPM is shown as decreasing, indicating that the vehicle is coming to a stop.

If the vehicle conditions such as zero vehicle speed, applied brake and accelerator pedal position allow zero, the hybrid ECM can 240 the machine (before the time 310 ). While the machine RPM like at the time 310 decreases beyond a threshold, the torque attenuation module 250 the auxiliary pump 212 to provide a boost pressure. After the elevation pressure at the time 312 has been applied for a predetermined interval, the torque attenuation module 250 the auxiliary pump 212 command a steady state pressure lower than the boost pressure.

The steady state pressure may be maintained for the remainder of the time the vehicle is stopped. At the time 314 The hybrid ECM will start a non-driver-commanded reboot. Approximately at this time, the torque mitigation module has 250 the auxiliary pump 212 to produce a reduced pressure. In addition, the torque mitigation module 250 a reduced gear ratio in the gear set 206 choose.

The value of the reduced pressure may be a function of the transmission oil temperature. The reduced pressure may be calibrated to match the pressure required to move the clutch plates of one of the friction devices 220 keep in touch, or something lies underneath. Thus, the clutch remains engaged, but with little ability to transmit torque.

After a predetermined delay, such as one second, the machine will be at the time 316 restarted. The delay allows the new, reduced pressure and / or the lower gear to decouple / decouple torque-transmitting components of the transmission. Then the gear set can 206 be reset to the previously selected gear ratio. Because of the reduced at the friction devices 220 supplied pressure, the torque generated by the engine restart is not as a jerk to the driveline 106 transfer. While the speed of the machine 102 increases, the oil pump takes over 210 supplying the pressure to the friction devices 220 , If the oil pump 210 generates sufficient pressure, the auxiliary pump 212 as at the time 318 is shown to be turned off.

Now on the basis of 4A FIG. 12 shows a flowchart of exemplary steps involved in controlling the hybrid powertrain 2A be executed. The control starts in step 402 where the controller determines if a machine shutdown event has been requested. If that is the case, the controller passes to step 404 ; otherwise the control remains in step 402 , Engine shutdown may be started when vehicle conditions such as zero vehicle speed, applied brake, and accelerator pedal position allow zero.

While the machine RPM in step 404 falls below a threshold, the pressure of the auxiliary pump 212 relied on a boost pressure level. The controller will step in 406 continued where the machine is switched off. For example, the fuel and spark delivery to the engine may be stopped. The controller will step in 408 continued, where the pressure of the auxiliary pump 212 is reduced to a steady value.

The controller will step in 410 continued where the controller determines if a machine restart is desired. If so, control is taken to step 412 transfer; otherwise the control remains in step 410 , In step 412 the controller determines if the restart was instructed by the driver. If that is the case, the controller passes to step 414 ; otherwise, the controller transfers to step 416 , A driver-ordered engine restart may result from the driver releasing the brake pedal or depressing the accelerator pedal.

In step 416 becomes the pressure of the auxiliary pump 212 reduced to a reduced pressure level. The reduced pressure level may be a function of the transmission oil temperature and may be determined from a look-up table indexed by the transmission oil temperature. The controller will be in the optional step 418 continued where the gear ratio of the gear set 206 is reduced.

The controller will step in 420 continued where the controller waits a predetermined delay period. The predetermined delay time period may be a function of internal pressure accumulators in the transmission, oil temperature, clutch pack size, and other factors. Thereafter, the controller in step 414 continued. In step 414 the machine is restarted.

The controller then becomes the optional step 422 continued. In step 422 becomes the gear ratio of the gear set 206 restored to the former gear ratio. For example only, the gear ratio can be restored to first gear. Thereafter, the controller in step 424 continued, where the auxiliary pump is turned off when the oil pump 210 reached a sufficient pressure. The controller then returns to step 402 back.

Now on the basis of 4B FIG. 12 shows a flowchart of exemplary steps involved in controlling the hybrid powertrain 2 B be executed. Until the step 412 the controller can look similar to the 4A be. In step 412 the controller determines if the engine restart is commanded by the driver. If that is the case, the controller passes to step 414 ; otherwise, the controller transfers to step 450 ,

In step 450 the control unit disengages the electronically controlled clutch. In this way, the torque converter 204 from the final drive 106 decoupled. The controller transfers to the optional step 418 where the control is the gear ratio of the gear set 206 can reduce. Thereafter, the controller in step 452 continued where the controller waits a predetermined delay. The predetermined delay time can be determined by the actuation time of the electronically controlled clutch 262 be determined.

Thereafter, the controller in step 414 continued where the machine is restarted. The controller then becomes the optional step 422 continued where the original gear ratio of the gear set 206 is restored. The controller will step in 454 continued where the electronically controlled clutch 262 is indented again. For example only, the electronically controlled clutch 454 be gradually re-engaged so that there is no sudden increase in torque to the powertrain 106 results. The controller will step in 424 continued, where the control is the auxiliary pump 212 turns off when the pressure from the oil pump 210 has reached a sufficient level. The controller then returns to step 402 back.

Claims (17)

A hybrid engine control system comprising: a hybrid engine control module ( 240 ), which is an internal combustion engine ( 102 ) optionally stops and that the internal combustion engine ( 102 ) based on Driver inputs and non-driver inputs optionally start; and a torque attenuation module ( 250 ), the torque transmission from the internal combustion engine ( 102 ) to a driveline ( 106 ) while the internal combustion engine ( 102 ) is started based on the non-driver inputs, and the torque transmission from the internal combustion engine ( 102 ) to the final drive ( 106 ) while the internal combustion engine ( 102 ) is started based on the driver input. Hybrid machine control system according to claim 1, wherein the torque attenuation module ( 250 ) the torque transmission by instructing a reduced hydraulic pressure from a pump ( 212 ) in a transmission ( 202 ) decreased. Hybrid engine control system according to claim 2, wherein the reduced hydraulic pressure is a function of the transmission oil temperature. Hybrid machine control system according to claim 2, in which the pump ( 212 ) through a charge storage module ( 216 ) is supplied with power. Hybrid machine control system according to claim 1, wherein the torque attenuation module ( 250 ) the torque transmission by disengaging an electronically controlled clutch ( 262 ) in a transmission ( 260 ) decreased. Hybrid machine control system according to claim 1, wherein the torque attenuation module ( 250 ) torque transmission by selecting a higher gear in a transmission ( 202 ) decreased. A hybrid engine control system according to claim 1, wherein the non-driver input is a low state of charge of a charge storage module ( 216 ). A hybrid engine control system according to claim 1, wherein the non-driver input is a demand signal from a heating, ventilation and air conditioning module ( 232 ). The hybrid engine control system of claim 1, wherein the driver inputs include signals from an accelerator pedal and a brake pedal. A method comprising: selectively stopping an internal combustion engine ( 102 ); selective starting of the internal combustion engine ( 102 ) based on driver input and non-driver input; Reducing the torque transmission from the internal combustion engine ( 102 ) to a driveline ( 106 ), while the internal combustion engine ( 102 ) is started based on the non-driver input; and maintaining the torque transmission from the internal combustion engine ( 102 ) to the final drive ( 106 ), while the internal combustion engine ( 102 ) is started based on the driver input. The method of claim 10, wherein reducing the torque transfer comprises instructing a reduced hydraulic pressure from a pump. 212 ) in a transmission ( 202 ). The method of claim 11, wherein the reduced hydraulic pressure is a function of transmission oil temperature. The method of claim 10, wherein reducing torque transmission comprises disengaging an electronically controlled clutch ( 262 ) in a transmission ( 260 ). The method of claim 10, wherein reducing torque transmission comprises selecting a higher gear in a transmission ( 202 ). Method according to Claim 10, in which the non-driver inputs comprise a low state of charge of a charge storage module ( 216 ). The method of claim 10, wherein the non-driver inputs comprise a demand signal from a heating, ventilation and air conditioning module ( 232 ). The method of claim 10, wherein the driver inputs include signals from an accelerator pedal and a brake pedal.

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