JP2007132238A - Engine power control device in start of vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To smoothly accelerate to early return to a normal throttle opening characteristic to prevent feeling of acceleration delay, even when an engine mounting vehicle, in which throttle opening is collected to be decreased so as to avoid feeling of abruptness of acceleration in the start, is started on the up-hill. <P>SOLUTION: In the start at t1 and on the up-hill, a start load degree α is detected at t2, by comparison with a flat road load. Reference throttle opening tTVOo corrected to be decreased to avoid the feeling of abruptness of acceleration in the start, is corrected to be increased to become a tTVOc depending on the load degree α at the start, and final target throttle opening tTVO is acquired from these tTVOo and tTVOc as follows. Target throttle opening deviation ΔTVOc=tTVOc-tTVOo is acquired, it passes through a first-order lag filter to provide target throttle opening deviation ΔTVOf after filtering, and the target throttle opening deviation ΔTVOf after filtering is added to the tTVOo so as to acquire the final target throttle opening tTVO. Since the expression of tTVO>tTVOo is satisfied, the throttle opening characteristic decreased by the correction is early returned to the normal throttle opening characteristic by the smooth acceleration so as to avoid the acceleration delay. <P>COPYRIGHT: (C)2007,JPO&INPIT

Description

  The present invention has been made such that, when starting a vehicle, it is possible not to cause a sudden feeling of acceleration at low loads, but to prevent insufficient driving force and deterioration of driving performance and efficiency at high loads. The present invention relates to an engine output control device for starting a vehicle.

Immediately after starting the vehicle, not only the engine output increases due to the depression of the accelerator pedal, but also a sudden increase in the vehicle acceleration due to, for example, the torque increasing effect due to the slip of the torque converter interposed between the engine and the automatic transmission. Tend to occur.
Although not intended to solve this problem, an engine output control technique at the time of starting has conventionally been proposed as described in Patent Document 1, for example.

  This proposed technology shows the change characteristics of the throttle opening TVO with respect to the accelerator pedal depression amount (accelerator opening) APO at extremely low vehicle speeds, such as garage entry, rather than the normal linear characteristics shown by the wavy line in FIG. The throttle opening TVO is assumed to be small, and this makes the throttle opening TVO less sensitive to the accelerator opening APO, making it easy to change the throttle opening required at extremely low vehicle speeds, such as garage entry. It can be done.

According to this proposed technique, referring to FIG. 11 (b) showing an operation time chart in the case of performing acceleration while keeping the accelerator opening APO constant, the throttle opening TVO at an extremely low vehicle speed where the vehicle speed VSP is less than VSP1. As a result, the sudden acceleration of the vehicle acceleration G indicated by the wavy line immediately after the start acceleration described above is indicated by the solid line, which is different from the original purpose described in Patent Document 1. It tends to be relaxed.
Japanese Patent Laid-Open No. 04-119228

Conventionally, however, the throttle opening TVO is corrected to decrease as shown in FIGS. 11 (a) and 11 (b) at the time of starting, but the vehicle load state at the time of starting is not taken into consideration. Arise.
In other words, under the vehicle operating conditions (vehicle weight, traction resistance, etc.) and driving conditions (road surface gradient, etc.) that are used as a reference when determining the throttle opening characteristics in FIG. When it is the reference load, the vehicle speed VSP rises smoothly as illustrated by the wavy line in FIG.
When the vehicle speed VSP reaches the same set vehicle speed VSP1 as shown in FIG. 11 (b), the instant t1 arrives early, and at this time the throttle opening TVO quickly corresponds to the linear characteristic as shown by the thick wavy line in FIG. 11 ( The normal throttle opening of a) is restored, and the driver does not feel that the starting acceleration is insufficient.

By the way, when the vehicle load state is higher than the reference load (for example, uphill road), the vehicle speed VSP does not increase as shown by the solid line in FIG. 12, and the vehicle speed VSP becomes the same set vehicle speed VSP1. Takes a long time to complete.
For this reason, the throttle opening TVO is always determined by the characteristics for extremely low vehicle speed in FIG. 11 (a), and the throttle opening TVO corresponds to the linear characteristic as illustrated by the solid line in FIG. ) Does not return to the normal throttle opening, and the driver feels that the starting acceleration is poor due to insufficient driving force.

In the conventional engine output control at the time of starting, for the same reason, the following problem also arises at the time of starting when the vehicle load state is higher than the reference load (for example, uphill road).
FIG. 13 is a time chart illustrating time-series changes in the accelerator opening APO, the throttle opening TVO, and the vehicle speed VSP when starting at a high load (uphill road).
From instant t1 to t2, the accelerator pedal was depressed to depress the accelerator pedal and the accelerator opening APO was kept at a value corresponding to the instant t3, and the vehicle started with a high load (uphill road). Since the opening degree TVO has been reduced and corrected by the throttle opening characteristic for extremely low vehicle speed shown in Fig. 11 (a), the driving speed is insufficient for starting a high load (uphill road), and the vehicle speed VSP rises as shown in the figure. Will not.

Therefore, the driver increases the accelerator pedal to increase the accelerator opening APO in hopes of acceleration at the instant t3 when it is felt that the vehicle speed VSP has risen easily.
As a result, even though the throttle opening TVO is continuously reduced and corrected by the throttle opening characteristic for extremely low vehicle speed, the opening is increased as shown in the figure in accordance with the increase in the accelerator opening APO, and the vehicle speed VSP is also increased accordingly. To do.
For this reason, the vehicle speed VSP increases more rapidly than the moment after the instant t3, and the driver feels the increase in the vehicle speed VSP due to the increase in driving force exceeding expectations at the instant t4, and returns the accelerator pedal to the accelerator opening APO. Along with this, the throttle opening TVO is also reduced.

If the throttle opening TVO is corrected to decrease as shown in FIGS. 11 (a) and 11 (b) without taking into account the load condition at the start as in the past,
When it is necessary to keep driving at a very low vehicle speed due to traffic congestion after starting a heavy load (uphill road), the above operation is repeated and the vehicle speed is likely to change.・ Continuous operation in the loaded state is difficult.

Further, in the conventional engine output control at the time of starting, for the same reason, the efficiency of the torque converter is improved as described below when the vehicle load state is higher than the reference load (for example, uphill road). The problem of getting worse.
FIG. 14 shows the ratio of the output rotational speed to the input rotational speed of the torque converter for the time series change of the accelerator opening APO, the time series change of the throttle opening TVO, and the time series change of the vehicle speed VSP similar to FIG. 3 is a time chart in which time-series changes of a speed ratio e and a torque converter transmission efficiency η are shown.

As shown in this figure, and as is apparent from the above, the vehicle speed VSP increases rapidly as indicated by the broken line when the reference load is applied, but gradually increases as indicated by the solid line when the load is high.
On the other hand, since the output speed of the torque converter, that is, the input speed of the transmission is determined by the vehicle speed VSP and the speed ratio (the lowest speed ratio for starting), the ratio of the output speed to the input speed of the torque converter As shown in FIG. 14, the represented speed ratio e is smaller at the time of high load when the vehicle speed VSP is gradually increased than at the reference load at which the vehicle speed VSP is rapidly increased,
As shown in FIG. 14, the transmission efficiency η of the torque converter having the characteristics shown in FIG. 15 according to the speed ratio e is smaller at the time of high load than at the reference load.

Here, the time axis of FIG. 14 is divided into A period, B period, and C period, and in each of these periods, which region on the characteristic line of transmission efficiency η shown in FIG. A, B, and C are as shown in FIG.
As is clear from this figure, according to the conventional engine output control at the time of starting, the transmission efficiency η of the torque converter is stopped in a worse region at the time of high load starting than at the time of reference load starting, which leads to deterioration of fuel consumption. There's a problem.

Since the present invention does not require much suppression of engine output for mitigating sudden acceleration of vehicle acceleration at the time of high load start, and the engine output such as a throttle valve in which the above problem has been performed for the suppression. From the viewpoint of reducing the amount of movement of the decision means,
When starting a high load on an uphill road or the like, the engine output control device at the start of the vehicle that can solve the above problem by increasing the operation amount of the engine output determining means that has been corrected for reduction. The purpose is to propose.

For this purpose, the engine output control device for starting a vehicle according to the present invention is constructed as described in claim 1.
First of all, to explain the starting engine output control device of the vehicle,
The engine output is determined by the amount of operation of the engine output determining means that is electronically controlled according to the accelerator pedal operation, and the amount of operation characteristic of the engine output determining means for the accelerator pedal operation is greater at the time of starting than at normal times other than at the time of starting. The operation amount of the engine output determining means is changed so as to decrease.

The present invention relates to an engine output control device at the start of such a vehicle.
A starting load degree detecting means for obtaining a degree of load on the vehicle at the time of starting;
Engine output correcting means for increasing and correcting the operation amount of the engine output determining means at the time of starting is provided according to the starting load degree obtained by this means.

According to the starting engine output control device of the present invention,
In order to increase and correct the starting operation amount of the engine output determining means determined to have the changed operation amount characteristic according to the degree of vehicle load at the start,
Even when starting with a high load (for example, uphill road), the vehicle speed can be quickly increased without running out of driving force. This makes it possible to return the engine output determining means to the operating amount characteristic suitable for normal times other than when starting. Can be completed quickly, and the aforementioned problem of start acceleration failure can be solved.

In addition, for the same reason, that is, since the driving force does not feel deficient even when starting a high load (for example, uphill road), the driver does not increase the accelerator pedal immediately after starting,
Vehicle speed changes are likely to occur when this additional stepping is necessary, and even after a heavy load (for example, uphill road) starts, even if a continuous operation in a road / road state with extremely low vehicle speed is required due to traffic jams, etc. While it ’s difficult to do this,
According to the present invention, since the accelerator pedal is not stepped on, continuous operation in a load / load state with such an extremely low vehicle speed is easy.

Further, according to the present invention, for the same reason, that is, the driving force does not become insufficient even when starting a high load (for example, uphill road),
When there is a fluid coupling such as a torque converter immediately after the engine, the speed ratio can be made relatively high even at high load start, the transmission efficiency of the fluid coupling determined according to this speed ratio is high, and the fuel consumption deteriorates. Can also be avoided.

Hereinafter, embodiments of the present invention will be described in detail based on examples shown in the drawings.
FIG. 1 shows a power train of a vehicle provided with a starting engine output control device according to an embodiment of the present invention, and its control system. The power train is composed of an engine 1 and a continuously variable transmission 2.
The engine 1 is a gasoline engine, but the throttle valve 3 that is the output determining means is not mechanically connected to the accelerator pedal 4 that is operated by the driver. Make electronic control.

  The operation amount of the throttle actuator 5 is controlled in response to a target throttle opening tTVO which is determined by the engine controller 6 according to the operation of the accelerator pedal 4 as will be described later, and the opening of the throttle valve 3 is thereby controlled by the target throttle opening. The output of the engine 1 is basically controlled so as to become a value corresponding to the operation of the accelerator pedal 4, but can be controlled by factors other than the operation of the accelerator pedal.

The engine controller 6 not only performs the throttle opening control via the throttle actuator 5 but is not shown in the figure, but other fuel injection amount control, fuel cut control, ignition timing, etc., which are necessary when the engine 1 is operated. Control and valve lift control of intake and exhaust valves are also performed.
These fuel injection amount control, fuel cut control, ignition timing control, and intake / exhaust valve lift amount control also determine the engine output, so the engine output determining means is not limited to the throttle valve 3 described above. Needless to say, it may be a device that controls the control.

The continuously variable transmission 2 is a well-known V-belt type continuously variable transmission, and a primary pulley 8 that is drivingly coupled to the output shaft of the engine 1 via a torque converter 7, a secondary pulley 9 that is aligned with the primary pulley 8, and both A V-belt 10 is provided between pulleys.
Then, the differential gear device 12 is drivingly coupled to the secondary pulley 9 via the final drive gear set 11, and the left and right driving wheels (not shown) are rotationally driven by these.

The speed change operation of the continuously variable transmission 2 is such that, among the flanges forming the V-grooves of the primary pulley 8 and the secondary pulley 9, one movable flange is brought relatively close to the other fixed flange to make the V-groove width. Narrowing the width or conversely increasing the V groove width,
The stroke positions of both movable flanges are determined by the ratio of the primary pulley pressure Ppri and the secondary pulley pressure Psec from the transmission control hydraulic circuit 13.

  The transmission control hydraulic circuit 13 includes a step motor 14 as a transmission actuator, and the transmission controller 15 is driven to a step position corresponding to the target transmission ratio im so that the continuously variable transmission 2 is set to the actual transmission ratio target. It is assumed that the continuously variable transmission is made to coincide with the transmission ratio im.

The engine controller 6 and the transmission controller 15 individually control the engine 1 and the continuously variable transmission 2 as described above. In addition to the input information, the engine controller 6 and the transmission controller 15 communicate the calculation results with each other. It is assumed that the transmission 2 is cooperatively controlled.
Therefore, to the engine controller 6, as input information common to both the controllers 6, 15, a signal from the accelerator opening sensor 21 that detects the depression amount (accelerator opening) APO of the accelerator pedal 4,
A signal from the input rotation sensor 22 for detecting the input rotation speed Ni of the continuously variable transmission 2, and
A signal from the engine rotation sensor 23 for detecting the engine speed Ne;
A signal from the vehicle speed sensor 24 for detecting the vehicle speed VSP;
A signal from the throttle opening sensor 25 for detecting the throttle opening TVO of the throttle valve 3, and
A signal from the output rotation sensor 26 for detecting the output rotation speed No of the continuously variable transmission 2 is input.

The transmission controller 15 uses the accelerator opening APO as a parameter, and based on a shift map obtained in advance as a two-dimensional map of the vehicle speed VSP and the target transmission input rotational speed tNi, the target input from the accelerator opening APO and the vehicle speed VSP. A rotation speed tNi is obtained, and a target gear ratio im = tNi / No obtained by dividing the target input rotation speed tNi by the transmission output rotation speed No is obtained.
Then, the speed change controller 15 drives the step motor 14 to a step position corresponding to the target speed change ratio im, thereby changing the continuously variable transmission 2 so that the actual speed change ratio i = Ni / No becomes the target speed change ratio im = tNi / No. It is assumed that the stepless speed change is made to match.

The engine controller 6 determines the target throttle opening tTVO by executing the control program shown in FIG. 2 in order to perform the engine output control at the start of the present invention.
First, in step S1 corresponding to the starting load degree detecting means in the present invention, the starting load degree α is calculated.
The starting load degree α is determined by the degree of load on the vehicle at the start of the vehicle and the reference vehicle operating state (vehicle weight, traction weight, etc. Driving conditions at the time of determination) and driving conditions (road surface gradient, road surface unevenness, etc., the reference driving conditions are the flat road when the throttle opening characteristic of FIG. 11 is determined, and the road surface without unevenness) It means the ratio to the reference load degree at and.

The degree of load can be calculated based on the acceleration at the time of starting, or can be calculated based on the engine output torque that can be obtained from information from the engine controller 15, but the calculation method described below with reference to FIG. Useful.
FIG. 3 shows a torque converter at the start of the vehicle which is performed by increasing the accelerator opening APO from 0 at the instant t1 as shown in the figure and changing the torque converter input rotational speed Ne, which is the engine rotational speed, with the passage of time as shown in FIG. The change with time of output rotation speed (transmission input rotation speed) Ni is illustrated.

  When starting under a standard load condition on a flat road or the like, the torque converter output rotational speed Ni changes with time so as to rise relatively quickly as shown by the solid line in FIG. The torque converter output rotational speed Ni changes over time as indicated by the wavy line in the same figure, and the amount corresponding to the gradient resistance is higher than that at the start of the reference load. The rise will be gradual.

At the instant t2 when the torque converter input rotation speed Ne rises to the load determination torque converter input rotation set value Nes due to the start of the vehicle, the torque converter output rotation speed Ni on the wavy line is converted to the load determination torque converter output rotation speed (determination rotation). Speed information) Set as Nij, and read the torque converter output speed Ni on the solid line at the same instant t2 (determined beforehand by experiments) and read it as the reference torque converter output speed (reference speed information) Nio .
Then, as shown in FIG. 3, the square root (Nij / Nio) ^1/2 of the ratio Nij / Nio between the load determination torque converter output rotational speed Nij and the reference torque converter output rotational speed Nio is defined as the load degree α at the start. Ask for.

In step S2 in FIG. 2, it is checked whether or not the start-time engine output control of the present invention can be started after the calculation of the start load degree α is completed. The process proceeds to step S3 corresponding to the means.
In this step S3, a reference target throttle opening tTVOo is obtained, and a corrected target throttle opening tTVOc is calculated by increasing it according to the starting load degree α.
First, the procedure for determining the reference target throttle opening tTVOo will be described with reference to FIG.
The target throttle opening calculation unit 31 for extremely low vehicle speed (starting) changes the target throttle opening tTVO (Low) for extremely low vehicle speed (starting) with respect to the accelerator opening APO as in FIG. Based on the map LowMap, the target throttle opening TVO (Low) for extremely low vehicle speed (starting) is obtained from the accelerator opening APO.
The normal target throttle opening calculation unit 32 other than at the extremely low vehicle speed is based on a change characteristic map HighMap of the normal target throttle opening tTVO (High) with respect to the accelerator opening APO similar to that in FIG. The normal target throttle opening TVO (High) is obtained from the accelerator opening APO.

The transition coefficient calculation unit 33 obtains a transition coefficient Kp for determining a transition form from the above-described extremely low vehicle speed (starting time) map LowMap to the normal time map HighMap.
The transition coefficient calculation unit 33 includes a transition coefficient map in which a change characteristic of the transition coefficient Kp with respect to the vehicle speed VSP is determined. The change characteristic of the transition coefficient Kp is lower than the transition start vehicle speed VSP1 with the transition coefficient Kp = 0. Keeping Kp = 0 at the vehicle speed, keeping Kp = 1 at the vehicle speed VSP2 higher than the transition end vehicle speed VSP2 with the transition coefficient Kp = 1, and moving from 0 to 1 as the transition coefficient Kp increases in the vehicle speed range from VSP1 to VSP2 It shall be gradually increased.
The transition coefficient calculation unit 33 calculates the transition coefficient Kp from the accelerator opening APO and the vehicle speed VSP to the extremely low vehicle speed (starting) map LowMap to the normal time map HighMap based on the change characteristic map of the transition coefficient Kp described above. Search and ask.

  The normal target throttle opening TVO (High) from the calculation unit 32 is weighted using the transition coefficient Kp according to the vehicle speed VSP as it is, and becomes Kp × TVO (High). The target throttle opening TVO (Low) for vehicle speed (starting) is weighted by (1−Kp) and becomes (1−Kp) × TVO (Low). The sum, that is, Kp × TVO (High) + (1−Kp) × TVO (Low) is set as the reference target throttle opening tTVOo.

  Therefore, as shown in FIG. 5, if the vehicle speed VSP is lower than the transition start vehicle speed VSP1, the reference target throttle opening tTVOo is determined based on the extremely low vehicle speed (starting) map LowMap, and the vehicle speed VSP is equal to or higher than the transition end vehicle speed VSP2. If the standard target throttle opening tTVOo is determined based on the normal map HighMap, and the vehicle speed VSP increases from VSP1 to VSP2, the extremely low vehicle speed (starting) map LowMap is interpolated to the normal map HighMap. However, the reference target throttle opening tTVOo is determined to gradually increase.

By the way, since the control program of FIG. 2 targets engine output control at the time of starting, the reference target throttle opening tTVOo obtained in step S3 means the reference target throttle opening tTVOo in the vehicle speed region VSP <VSP2 of FIG. Shall.
Incidentally, the reference target throttle opening tTVOo for normal use in the vehicle speed region VSP ≧ VSP2 in FIG. 5 is used as the final target throttle opening tTVO for the throttle opening control as it is.
However, in step S3 in FIG. 2, the corrected target throttle opening tTVOc is obtained by correcting and increasing the reference target throttle opening tTVOo as follows according to the aforementioned starting load degree α.

When correcting the reference target throttle opening tTVOo, first, based on the planned maximum opening correction map at high load start as shown in FIG. 6, the maximum opening at high load start is determined from the accelerator opening APO and the vehicle speed VSP. The degree correction amount ΔTVOmax is determined.
This maximum opening correction amount ΔTVOmax at high load start is defined as the allowable maximum target throttle opening tTVOmax that is raised by the hatching area when the reference target throttle opening tTVOo changes with time as shown in FIG. Therefore, the increase correction of the reference target throttle opening tTVOo can be substantially limited to this tTVOmax, and the uncomfortable feeling due to the excessive increase correction can be avoided.

Then, multiply the maximum opening correction amount ΔTVOmax at high load start by the load degree α at start to obtain the increase correction amount ΔTVOc of the reference target throttle opening tTVOo, and add this to the reference target throttle opening tTVOo to obtain the corrected target Find the throttle opening tTVOc.
tTVOc ＝ tTVOo ＋ α × ΔTVOmax

  Next, in step S4 of FIG. 2, the final target throttle opening tTVO is obtained from the corrected target throttle opening tTVOc. In this calculation, as shown in FIG. 8, the reference target throttle opening is calculated from the corrected target throttle opening tTVOc. The target throttle opening deviation ΔTVOc = tTVOc−tTVOo is obtained by subtracting the degree tTVOo, and the filtered target throttle opening deviation ΔTVOf obtained through the first-order lag filter 34 is added to the reference target throttle opening tTVOo. Find the final target throttle opening tTVO.

In this embodiment, the final target throttle opening tTVO obtained as described above is commanded to the throttle actuator 5 in FIG.
As a result, the actual throttle opening TVO is made equal to the final target throttle opening tTVO by the throttle actuator 5, and the engine output torque Te determined by this and the engine speed Ne is generated.

The operation of the above-described embodiment will be described below at the time of starting when the accelerator opening APO is increased from 0 at the instant t1 as shown in FIG.
After this start, assuming that the starting load degree α is obtained at the instant t2 as described above with reference to FIG. 3, from the instant t2 to the transition end instant t3 where the vehicle speed becomes VSP ≧ VSP2 (see FIGS. 4 and 5). 8 is calculated based on the reference target throttle opening tTVOo required as described above with reference to FIG. 4 and the corrected target throttle opening tTVOc required as described above with reference to FIGS. 6 and 7. Thus, the final target throttle opening tTVO is obtained as shown in FIG.

When starting at a high load (for example, uphill road) where the starting load degree α is calculated, the final target throttle opening tTVO is made larger than the reference target throttle opening tTVOo during the start t2-t3. Since the reference target throttle opening tTVOo is corrected to increase to the final target throttle opening tTVO according to the starting load degree α,
Even at the start of a heavy load (for example, uphill road), the vehicle speed VSP can be quickly raised as shown in the figure without running out of driving force, and the transition instant t3 where the vehicle speed becomes VSP ≧ VSP2 can be reached early. The return to the normal target throttle opening tTVO (High) can be completed quickly, and the problem of the start acceleration failure at the time of high load start can be solved.

In addition, for the same reason, that is, since the driving force does not feel deficient even when starting a high load (for example, uphill road), the driver does not increase the accelerator pedal immediately after starting,
Vehicle speed changes are likely to occur when this additional stepping is necessary, and even after a heavy load (for example, uphill road) starts, even if a continuous operation in a road / road state with extremely low vehicle speed is required due to traffic jams, etc. While it ’s difficult to do this,
According to this embodiment, since the accelerator pedal is not stepped on, continuous operation in a road / road state maintaining such an extremely low vehicle speed is easy.

Further, according to the present embodiment, for the same reason, that is, the driving force does not become insufficient even when starting a high load (for example, uphill road),
When there is a fluid coupling such as the torque converter 7 immediately after the engine 1, the speed ratio can be made relatively high even at high load start, the transmission efficiency of the fluid coupling determined according to this speed ratio is also high, and fuel consumption Deterioration can also be avoided.

  As in this embodiment, when obtaining the final target throttle opening tTVO from the corrected target throttle opening tTVOc, as described above with reference to FIG. 8, the target throttle opening deviation ΔTVOc = tTVOc−tTVOo first-order lag filtering value ΔTVOf Is added to the reference target throttle opening tTVOo to obtain the final target throttle opening tTVO, the following effects are obtained.

That is, when determining the final target throttle opening tTVO from the corrected target throttle opening tTVOc, instead of the above, the corrected target throttle opening tTVOc may be passed through a first-order lag filter to be the final target throttle opening tTVO. Conceivable.
However, as shown in FIG. 10, the case where the vehicle starts at the instant t1 and the accelerator pedal is depressed again at the instant t4 after judging the high load at the instant t2 will be explained. The target throttle opening tTVOo and the corrected target throttle opening tTVOc also rise rapidly as shown in the figure.
On the other hand, the value obtained by passing the corrected target throttle opening tTVOc through the first-order lag filter is the reference target throttle opening tTVOo and the corrected target throttle as shown by the two-dot chain line as the filtered value of tTVOc in the figure. The time series changes more slowly than the opening degree tTVOc and becomes smaller than the reference target throttle opening degree tTVOo in the period indicated by hatching, and the object of the present invention cannot be achieved in this period.

  However, as in this embodiment, the target throttle opening deviation ΔTVOc = tTVOc−tTVOo obtained by subtracting the final target throttle opening tTVOc from the corrected target throttle opening tTVOc is added to the reference target throttle opening tTVOo. The final target throttle opening tTVO, the final target throttle opening tTVO becomes as shown by a thick wavy line after the instant t4, and never becomes smaller than the reference target throttle opening tTVOo, The above-described effects can be made more remarkable without generating a period during which the object of the present invention cannot be achieved.

1 is a system diagram showing a vehicle power train including a starting engine output control device according to an embodiment of the present invention, together with its control system. It is a flowchart which shows the engine output control program at the time of start which the engine controller in the same power train control system performs. FIG. 3 is a change time chart of a starting load degree determined in the starting engine output control program shown in FIG. 2. FIG. FIG. 3 is a functional block diagram of a reference target throttle opening calculation process in the starting engine output control program shown in FIG. 2. It is a change characteristic figure of the standard target throttle opening. It is a block diagram which shows the calculation process of the maximum opening degree correction amount at the time of high load start regarding the throttle opening degree. It is a time chart which shows the relationship between a reference | standard target throttle opening degree, the maximum opening amount correction amount at the time of high load start, the corrected target throttle opening degree, and the load degree at the time of start. It is a functional block diagram showing processing for calculating a final target throttle opening from a reference target throttle opening and a corrected target throttle opening. FIG. 9 is an operation time chart of the embodiment shown in FIGS. It is an operation | movement time chart at the time of the accelerator pedal depression start of the Example. The conventional engine output control is shown, (a) is a control characteristic diagram of the throttle opening with respect to the accelerator opening for the engine output control, (b) is an explanation showing the state of occurrence of vehicle acceleration by the throttle opening control FIG. It is a time chart which shows the change state of throttle opening and a vehicle speed compared with the case where the conventional engine output control is performed at the time of a reference load, and when it is performed at the time of a high load. 5 is a time chart showing a driver's accelerator pedal operation when using a conventional engine output control at high load start, and a change in throttle opening and a change in vehicle speed associated therewith. It is a time chart which shows the change state of the speed ratio and transmission efficiency of a torque converter compared with the case where the conventional engine output control is performed at the time of a reference load, and when it is performed at the time of a high load. It is a diagram which shows the change characteristic of the transmission efficiency with respect to the speed ratio of a torque converter.

Explanation of symbols

1 engine 2 continuously variable transmission (automatic transmission)
3 Throttle valve (engine output determining means)
4 Accelerator pedal 5 Throttle actuator 6 Engine controller 7 Torque converter (fluid coupling)
8 Primary pulley 9 Secondary pulley
10 V belt
11 Final drive gear set
12 Differential gear unit
13 Shift control hydraulic circuit
14 Step motor
15 Transmission controller
21 Accelerator position sensor
22 Input rotation sensor
23 Engine rotation sensor
24 Vehicle speed sensor
25 Throttle opening sensor
26 Output rotation sensor
31 Target throttle opening calculator for extremely low vehicle speed (when starting)
32 Target throttle opening calculator for normal operation
33 Transition coefficient calculator
34 First-order lag filter

Claims (6)

The engine output is determined by the amount of operation of the engine output determining means that is electronically controlled according to the accelerator pedal operation, and the amount of operation characteristic of the engine output determining means for the accelerator pedal operation is greater at the time of starting than at normal times other than at the time of starting. In the engine output control device at the start of the vehicle, the operation amount of the engine output determining means is changed in a direction that decreases.
A starting load degree detecting means for obtaining a degree of load on the vehicle at the time of starting;
An engine output control device at the time of start of a vehicle, comprising engine output correction means for increasing and correcting an operation amount of the engine output determination means at the time of start according to the degree of start load obtained by this means. In the vehicle start engine output control device according to claim 1,
The engine output control device at the time of start of the vehicle, wherein the engine output correction means sets an upper limit value to an amount for increasing and correcting the operation amount of the engine output determination means at the time of start. In the start engine output control device of the vehicle according to claim 2,
The engine output control device at the start of the vehicle, wherein the engine output correction means determines an upper limit value of an increase correction amount related to an operation amount of the engine output determination means in accordance with a vehicle speed and an accelerator pedal operation amount. . In the start engine output control device of the vehicle according to claim 2 or 3,
The starting load degree detection means obtains the load degree that reaches the vehicle at the time of starting by comparing with the reference load degree under the driving condition of the vehicle and the driving condition,
The engine output correcting means determines the engine output at the time of starting by an amount obtained by multiplying the increase correction amount upper limit value related to the operation amount of the engine output determining means by the starting load degree obtained by the starting load degree detecting means. An engine output control device for starting a vehicle, characterized in that the operation amount of the means is increased and corrected. In the engine output control device at the start of the vehicle according to any one of claims 1 to 4,
The engine output correcting means is a first-order lag filter for a deviation between an operation amount before correction of the engine output determining means corresponding to the starting operation amount characteristic and an operation amount after correction of the increased engine output determining means. A starting engine output control device for a vehicle, characterized in that a value obtained by adding the post-filtering deviation obtained through the above to the operation amount before correction is used as a final operation amount of the engine output determining means. The start engine output control device according to any one of claims 1 to 5, which is used in a vehicle equipped with an automatic transmission that shifts the rotation of the engine input via a fluid coupling and directs the rotation to a wheel. ,
The starting load degree detecting means is:
A rotational speed information detection means for determination that detects output-side rotational speed information of the fluid coupling when the input rotational speed of the fluid coupling reaches a set value by the start, and sets the rotational speed information for determination;
Reference rotation related to the output side rotational speed information obtained when the input rotational speed of the fluid coupling reaches the set value, which is obtained in advance at the time of starting under the driving state and traveling conditions of the reference vehicle A starting engine output control device for a vehicle, comprising: a starting load degree detecting means for detecting a starting load degree by comparing speed information with the determination rotational speed information.

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