JP2001310654A - Driving force control device for hybrid vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To reduce a wasted electric power and fuel consumption and to perform a creep driving capable of meeting a hill or a step. SOLUTION: A target creep torque is computed from a vehicle speed Vcar in a target creep torque compute 31 and is annealed in a filter process 32. Then using the annealed target creep torque, a creep driving engine torque is computed in a target engine torque compute 33. On the other hand, an actual clutch torque is calculated in a clutch torque calculation 38 and the target creep torque is adjusted by adding a disturbance factor to the vehicle in a target creep torque adjust 35. The obtained value deducted from the adjusted target torque by the clutch torque is set to be a motor torque on creep driving.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a driving force control device for a hybrid vehicle which uses an engine and a motor as driving sources and has a clutch for switching the power of an engine to driving wheels.

[0002]

2. Description of the Related Art In a driving force control device of this kind, as a technique for preventing waste of energy consumption due to creep torque without impairing operability during reverse travel, a creep disclosed in Japanese Patent Application Laid-Open No. 11-69508 is disclosed. Torque control devices are known. Further, as a technique for restricting the creep running speed when the temperature of the engine cooling water is low to within a predetermined range, for example, a technique is known from Japanese Patent Application Laid-Open No. H11-141365.

[0003]

However, the technique disclosed in Japanese Patent Application Laid-Open No. H11-69508 only keeps the creep torque constant.
According to the technology disclosed in Japanese Patent Application Laid-Open No. 141365, when the engine speed at low water temperature is high, the vehicle speed is merely kept within a certain range by regenerating the motor, so that the following requirements cannot be sufficiently satisfied. could not. Realization of smoother and safer creep driving. Realization of creep running with less wasteful power and fuel consumption. Realizes creep running that can respond to disturbances such as slopes and steps.

The present invention has been made in view of the above circumstances, and an object of the present invention is to realize smooth and safer creep running. Another object of the present invention is to realize creep running with less wasteful power and fuel consumption. Still another object of the present invention is to realize creep running that can cope with disturbance such as a slope and a step.

[0005]

Means for Solving the Problems In order to solve the above problems, the present invention employs the following means. The invention according to claim 1 uses an engine (for example, the engine 1 in the embodiment) and a motor (for example, the main electric motor 8 in the embodiment) as a drive source, and uses a drive wheel of engine power (for example, a drive wheel in the embodiment). 9) A driving force control device for a hybrid vehicle including a clutch (for example, the starting clutch 6 in the embodiment) for switching between on and off, wherein an engine torque during creep running is determined using a target creep torque obtained from a vehicle speed. Torque setting means (for example, the engine ECU in the embodiment)
11), clutch torque estimating means for estimating the actual clutch torque (for example, the clutch torque estimating unit 38 in the embodiment), and a value obtained by subtracting the clutch torque from the target creep torque during creep running. Motor torque setting means for setting the motor torque (for example,
Motor ECU 12) according to the embodiment.

According to this structure, when the target creep torque obtained from the vehicle speed is insufficient or excessive with respect to the actually required creep torque, the motor having a fast response is not caused by the engine torque having a relatively slow response. The torque makes it possible to adjust the creep torque.

According to a second aspect of the present invention, there is provided the driving force control apparatus according to the first aspect, wherein a target creep torque correcting means for correcting the target creep torque in consideration of disturbance to a vehicle (for example, a target creep in the embodiment). A torque correction unit 35) is provided, and the motor torque setting means sets a value obtained by subtracting the clutch torque from the corrected target creep torque as the motor torque.

[0008] According to this configuration, when obtaining the motor torque, the disturbance actually received by the vehicle is taken into consideration, so that the compensating ability by the motor torque is improved.

According to a third aspect of the present invention, in the driving force control apparatus according to the second aspect, the engine torque setting means sets the engine torque using the corrected target creep torque.

According to this configuration, in determining the engine torque, the disturbance actually received by the vehicle is taken into consideration, so that the followability of the engine torque to the actually required creep torque is improved.

[0011] The invention of claim 4 is the invention of claim 2 or claim 3.
The driving force control device according to claim 1, further comprising a vehicle running resistance detecting unit that detects a vehicle running resistance, wherein the target creep torque correcting unit increases or decreases the target creep torque according to the running resistance detected by the vehicle running resistance detecting unit. It is characterized by correction.

According to this configuration, when the running resistance becomes equal to or less than the predetermined value, a negative torque is generated by the motor.
If the running resistance exceeds a predetermined value, a positive torque is generated by the motor, so that the creep torque can be adjusted up and down, so that it is possible to flexibly cope with a change in the running resistance.

[0013] The invention of claim 5 is the invention of claim 2 or claim 3.
The driving force control device according to claim 1, further comprising acceleration detection means for detecting vehicle acceleration, wherein the target creep torque correction means corrects increase or decrease of the target creep torque according to the vehicle acceleration detected by the acceleration detection means. And

According to this configuration, even if the running resistance changes suddenly, the creep torque can be adjusted in accordance with the detected acceleration, so that it is possible to prevent sudden acceleration / deceleration of the vehicle. Become.

[0015] The invention of claim 6 is the invention of claim 2 or claim 3.
The driving force control device according to claim 1, further comprising: a brake depression force detection unit that detects a brake depression force, wherein the target creep torque correction unit increases or decreases the target creep torque according to the brake depression force detected by the brake depression force detection unit. It is characterized by.

According to this configuration, when the brake depression force is equal to or more than the predetermined value, the engine torque and the motor torque can be reduced (including 0).

According to a seventh aspect of the present invention, in the driving force control apparatus according to any one of the first to sixth aspects, the engine torque setting means causes the engine torque to follow the target creep torque. And

According to this configuration, it is possible to generate all of the creep torque in the steady state by the engine.

[0019]

Embodiments of the present invention will be described below with reference to the drawings. First Embodiment FIG. 1 is a diagram showing a power transmission system of a hybrid vehicle. The power transmission system includes an engine 1, an oil pump 2, a torque converter 3, a forward / reverse switching planetary gear 4, and a continuously variable transmission. Machine 5, starting clutch 6, differential 7, sub-motor 8a, main motor (motor) 8b, drive wheel 9, engine ECU (engine torque setting means) 11, and motor ECU (motor torque setting means) 12 are main components. It is a component.

The engine ECU 11 obtains an engine torque from the accelerator opening Ap detected by various sensors, the vehicle speed Vcar, the engine speed Ne, the intake pipe absolute pressure Pb, and the like, and supplies a command value EngTrqCmd to the engine 1 based on the engine torque. The output controls the engine during creep running. On the other hand, the motor ECU 12 obtains a motor torque using an output from the engine ECU 12 and outputs a command value MotTrqCmd based on the motor torque to the main motor 8b, thereby performing motor control during creep running and controlling the sub-motor 8a. Also do.

The continuously variable transmission 5 includes V-type transmission pulleys 51 and 52 whose widths vary between a transmission input shaft and a transmission output shaft, and a number of blocks are interposed between the V-type transmission pulleys 51 and 52. CVT (Continuo) that transmits power by wrapping around a steel belt 53 composed of a steel belt and two sets of steel bands
sly Variable Transmission). The widths of the V-shaped speed change pulleys 51 and 52 vary according to the oil pressure supplied from the oil pump 2.

The forward / reverse switching planetary gear 4 switches the rotation direction of the engine power input to the drive-side V-type transmission pulley 51 of the continuously variable transmission 5. Also, the starting clutch 6
Switches on / off of the engine power input to the driven V-type shift pulley 52 of the continuously variable transmission 5 to the drive wheels 9. The differential device 7 is a device that gives a differential rotation speed to the left and right wheels with respect to a rotation difference generated between the left and right wheels depending on running conditions such as a turning of the vehicle. And are engaged.

In the power transmission system configured as described above, the engine torque generated by the engine 1 is controlled by the sub-motor 8a, the oil pump 2, the torque converter 3, the forward / reverse switching planetary gear 4, the continuously variable transmission 5, the starting clutch. 6, driving gear 9 via intermediate gear 22 and differential 7
And the motor torque generated by the main motor 8 is transmitted to the drive wheels 9 via the intermediate shaft 22 and the differential 7.

From the above, in the power transmission system shown in FIG. 1, the target creep torque is obtained by adding the motor torque to the clutch torque obtained by multiplying the engine torque by the transmission efficiency ε. Note that the transmission efficiency ε is the speed ratio Ratio of the continuously variable transmission 5.
And the CVT efficiency CvtEf, the clutch efficiency Esc of the starting clutch 6, the slip friction μ, and the like.

Next, the processing performed by the engine ECU 11 and the motor ECU 12 during creep running will be described with reference to FIG. In this figure, a target creep torque calculator 31, a filter processor 32, a target engine torque calculator 33, a vehicle acceleration calculator 34, a target creep torque corrector 35, a vehicle running resistance calculator 36, an engine torque estimator 37, and The clutch torque estimating unit 38 is a component of the engine ECU 11, and the deviation calculating unit 39 is a component of the motor ECU 12.

The target creep torque calculating section 31 uses the vehicle speed VCar detected by the vehicle speed sensor in advance as shown in FIG.
By searching a map associating the vehicle speed Vcar and the target creep torque command value CreepTrqFCmd created as shown in FIG.
By substituting r, the target creep torque command value C
reepTrqFCmd is calculated. The map shown in FIG. 3B is obtained by performing a filtering process on FIG. 3A showing the correlation between the vehicle speed VCar and the target creep torque. Supplementary to FIG. 3A, the target creep torque when “Vcar = 0” is set from the viewpoint of what kind of creep torque can prevent the vehicle from slipping down on an assumed slope. And the vehicle speed Vcar
Is the maximum creep speed on flat ground (for example, 10 km / h)
, The target creep torque is set to “0”.

The target creep torque command value CreepTrqFCmd calculated by the target creep torque calculator 31 is input to the filter processor 32 and the target creep torque corrector 35. In the filter processing unit 32, the target creep torque command value CreepTrqFCmd is smoothed, and the smoothed target creep torque command value CreepTrqFCmd is processed.
Is input to the target engine torque calculation unit 33.

In the target engine torque calculating section 33, the smoothed target creep torque command value CreepTrqFCmd
From the speed ratio Ratio and the CVT efficiency CvtEf of the continuously variable transmission 5, an engine torque command value EngTrq given to the engine 1 is calculated.
Cmd is calculated. The engine torque command value EngTrqCmd calculated by the target engine torque calculation unit 33 is
Input to the engine 1.

On the other hand, the target creep torque correction unit 35 calculates the target creep torque command value CreepTrqFCmd calculated by the target creep torque calculation unit 31 and the vehicle acceleration calculated by the vehicle acceleration calculation unit 34 based on the signal from the G sensor. The brake depression force detected by the vehicle running resistance calculated by the vehicle running resistance calculating unit 36 based on signals from various sensors that detect running resistance such as road surface inclination, steps, and vehicle weight, which are disturbances to the vehicle, Target creep torque command value
CreepTrqFCmd is corrected. The road surface inclination is calculated from the 3D (dimensional) map information stored in the map data memory of the navigation device, the distance from the front end of the vehicle to the road surface and the distance from the rear end of the vehicle to the road surface measured by the distance measuring sensor. Can be detected. In addition, although errors due to vehicle weight, shaking, and the like are large, they can be detected by a 3D gyro sensor, and can be estimated from brake fluid pressure or motor torque that can stop the vehicle at a certain inclination. The presence of a step in the traveling direction can be detected by arranging two or more distance measuring sensors in the vertical direction on the front side of the front wheel and behind the rear wheel and comparing the sensor outputs. The change in the vehicle weight can be estimated from the sinking amount of the suspension when the vehicle stops, which is measured by a displacement sensor or a distance measuring sensor. The basic running resistance can be obtained from a running resistance value (table or characteristic value) predetermined for the vehicle speed.

The engine torque estimating section 37 estimates the engine torque actually generated in the engine 1 from the engine speed Ne and the intake pipe absolute pressure Pb. In the clutch torque estimating section 38, the engine torque estimating section 37
The clutch torque actually generated is estimated from the estimated engine torque estimated in the above, the speed ratio Ratio and CVT efficiency CvtEf of the continuously variable transmission 5, the clutch efficiency Esc of the starting clutch 6, the sliding friction μ, and the like. You.

The deviation calculating section 39 corrects the target creep torque command value Cree corrected by the target creep torque correcting section 35.
By subtracting the clutch torque estimated by the clutch torque estimating unit 38 from pTrqFCmd, a motor torque command value MotTrqCmd given to the main electric motor 8b is calculated. Then, the motor torque command value MotTrqCmd calculated by the deviation calculator 39 is input to the main motor 8.

As described above, according to the driving force transmission device according to the present embodiment, when the target creep torque obtained from the vehicle speed Vcar is insufficient or excessive with respect to the actually required creep torque, Since the torque can be adjusted by the motor torque having a fast response without depending on the engine torque having a relatively slow response, it is possible to effectively prevent the vehicle from slipping down a slope due to a delay in rising of the engine torque.

In determining the motor torque,
Since the disturbance actually received by the vehicle is taken into consideration, the compensation accuracy of the motor torque for compensating for the deviation between the required creep torque and the engine torque is improved, and waste of power consumption can be prevented.

In particular, when the running resistance falls below a predetermined value, the main motor 8 generates a negative torque, and when the running resistance exceeds the predetermined value, the main motor 8 generates a positive torque. Since the creep torque can be adjusted, it is possible to flexibly cope with a change in running resistance. In addition, in the steady state, the creep running can be performed only by the engine torque, so that the state in which the running resistance is small continues for a long time, so that the main motor 8 is fully charged and the negative torque cannot be added to the engine torque. Can be avoided.

Further, even when the running resistance changes suddenly, it is possible to prevent sudden acceleration and deceleration of the vehicle by adjusting the creep torque in accordance with the acceleration detected by the G sensor. Therefore, smoother and safer creep can be realized. Further, when the brake depression force is equal to or more than a predetermined value, the engine torque and the motor torque can be reduced (including 0), so that unnecessary power and fuel consumption can be prevented, and
Since there is no need to increase the brake depression force even during deceleration, a decrease in driving feeling can be prevented.

FIG. 4 is a diagram showing the correlation between the target creep, the clutch torque, and the motor torque with respect to changes in the vehicle speed and the running resistance. As shown in this figure, in section A, which is the initial stage of creep running, the clutch torque has not sufficiently followed the target creep torque, but the deviation is quickly compensated by adding a positive motor torque. Will be.

In the section B where the vehicle receives a positive running resistance such as a step, for example, although the target creep torque could be achieved only by the clutch torque until then, the clutch torque is reduced by the running resistance. The deviation will be compensated quickly with a positive motor torque, albeit a slight shortage. Contrary to section B, section C corresponds to a case where the vehicle receives a negative running resistance such as a hill.
In this case, the clutch torque becomes excessive with respect to the target creep torque, but the deviation is quickly compensated by the negative motor torque.

[Second Embodiment] Next, a second embodiment of the present invention will be described with reference to FIG. The components shown in this figure are the same as the components according to the first embodiment shown in FIG.

In the first embodiment, the target creep torque calculated by the target creep torque calculation section 31 is directly input to the filter processing section 32, whereas in the present embodiment, the target creep torque calculation section 31 The target creep torque calculated in step 1
5 and corrected to the target creep torque in consideration of disturbance, and then input to the filter processing unit 32.

In this case, when obtaining not only the motor torque but also the engine torque, the disturbance actually received by the vehicle is taken into consideration, so that the followability of the engine torque to the required creep torque is improved. Therefore, together with the improvement of the motor torque adjustment accuracy, it is possible to further prevent power consumption during creep running.

In each of the above embodiments,
Even if the vehicle speed Vcar enters a region where a regenerative negative torque should be generated when traveling on a slope, if the creep traveling state continues,
A negative motor torque command value MotTrqCmd is supplied to the main motor 8b.
Is not output. This is to prevent hunting of drive / regeneration. Conversely, when the vehicle speed Vcar falls from the deceleration regeneration region to the creep traveling region, a negative motor torque command value MotTrqCmd is output to the main motor 8b. Otherwise, it is necessary to increase the brake depression force between the end of regeneration and the stop of the vehicle.

[0042]

As is apparent from the above description, according to the present invention, the following effects can be obtained. (1) According to the first aspect of the present invention, when the target creep torque obtained from the vehicle speed is insufficient or excessive with respect to the actually required creep torque, the response is not caused by the relatively slow response engine torque. Since the creep torque can be adjusted by the fast motor torque, it is possible to effectively prevent the vehicle from slipping down a slope due to a delay in rising engine torque.

(2) According to the second aspect of the present invention, since the disturbance actually received by the vehicle is taken into account in obtaining the motor torque, the ability to compensate for the motor torque is improved.

(3) According to the third aspect of the present invention, in determining the engine torque, the disturbance actually received by the vehicle is taken into consideration, so that the followability of the engine torque to the actually required creep torque is improved. I do.

(4) According to the fourth aspect of the present invention, when the running resistance falls below a predetermined value, a negative torque is generated by the motor, and when the running resistance exceeds the predetermined value, the motor generates a negative torque. By generating the positive torque, the creep torque can be adjusted, so that it is possible to flexibly cope with a change in the running resistance.

(5) According to the fifth aspect of the present invention, even when the running resistance changes suddenly, the creep torque can be adjusted in accordance with the detected acceleration. It is possible to realize smoother and safer creep running.

(6) According to the invention of claim 6, when the brake depression force is equal to or more than a predetermined value, it becomes possible to reduce the engine torque and the motor torque (including 0).
Unnecessary power and fuel consumption can be prevented. Further, it is possible to prevent a decrease in driving feeling during deceleration.

(7) According to the seventh aspect of the present invention, all of the creep torque in the steady state can be generated by the engine, so that wasteful power and fuel consumption can be prevented. Further, even when creep running with low running resistance continues for a long time, it is possible to avoid a situation in which the negative torque from the motor cannot be added to the engine torque.

[Brief description of the drawings]

FIG. 1 is a power transmission system diagram of a hybrid vehicle according to an embodiment of the present invention.

FIG. 2 is a block diagram illustrating a process of calculating engine torque and motor torque.

3A is a correlation diagram between a vehicle speed and a target creep torque, and FIG. 3B is a map diagram showing a correlation between a vehicle speed and a target creep torque command value created by performing a filtering process on FIG.

FIG. 4 is a diagram showing a correlation between a target creep, a clutch torque, and a motor torque with respect to changes in vehicle speed and running resistance.

FIG. 5 is a block diagram showing another calculation process of the engine torque and the motor torque.

[Explanation of symbols]

Reference Signs List 1 engine 6 starting clutch (clutch) 8b main motor (motor) 9 driving wheel 11 engine ECU (engine torque setting means) 12 motor ECU (motor torque setting means) 38 clutch torque estimating section (clutch torque estimating means) 35 target creep Torque correction unit (target creep torque correction means) 36 Vehicle running resistance calculation unit (running resistance detecting means) Vcar Vehicle speed

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) B60L 11/14 F02D 29/06 D F02D 29/06 L 45/00 364A 45/00 364 B60K 9/00 E (72) Inventor Yusuke Tatara 1-4-1 Chuo, Wako-shi, Saitama F-term in Honda R & D Co., Ltd. (reference) 3D041 AA21 AA44 AA45 AB01 AC01 AC06 AC20 AC26 AD01 AD02 AD05 AD10 AD31 AD41 AD51 AE02 AE03 AE05 AE41 AE41 AF01 3G084 BA02 CA03 CA04 DA02 DA25 EA01 EA04 EB12 EB25 EC03 FA05 FA06 FA10 FA33 3G093 BA19 CA04 CB06 DA01 DA03 DA06 DB05 DB10 DB15 DB21 EA02 EC02 FA02 FA03 FB01 FB02 5H115 PA08 PA12 PC06 PG04 PI16 TO09 TOE TO23

Claims (7)

[Claims] 1. A driving force control device for a hybrid vehicle having an engine and a motor as a driving source and having a clutch for switching between intermittent and intermittent driving of engine power to a driving wheel, wherein the creep running uses a target creep torque obtained from a vehicle speed. Engine torque setting means for setting the engine torque at the time, clutch torque estimating means for estimating the actual clutch torque, and setting a value obtained by subtracting the clutch torque from the target creep torque as a motor torque during creep running. A driving force control device for a hybrid vehicle, comprising: 2. A target creep torque correcting means for correcting the target creep torque in consideration of disturbance to a vehicle, wherein the motor torque setting means obtains the target creep torque by subtracting the clutch torque from the corrected target creep torque. The driving force control device for a hybrid vehicle according to claim 1, wherein the value obtained is the motor torque. 3. The driving force control device for a hybrid vehicle according to claim 2, wherein the engine torque setting means sets the engine torque using a corrected target creep torque. 4. A vehicle running resistance detecting means for detecting a vehicle running resistance, wherein the target creep torque correcting means corrects increase or decrease of the target creep torque according to the running resistance detected by the vehicle running resistance detecting means. The driving force control apparatus for a hybrid vehicle according to claim 2, wherein 5. An acceleration detecting means for detecting a vehicle acceleration, wherein the target creep torque correcting means corrects increase or decrease of the target creep torque according to the vehicle acceleration detected by the acceleration detecting means. The driving force control apparatus for a hybrid vehicle according to claim 2 or 3. 6. A braking force detecting means for detecting a braking force, wherein the target creep torque correcting means increases or decreases the target creep torque in accordance with the braking force detected by the braking force detecting means. Claim 2
A driving force control device for a hybrid vehicle according to claim 3. 7. The driving force control apparatus for a hybrid vehicle according to claim 1, wherein the engine torque setting means causes the engine torque to follow the target creep torque.