JP3463566B2 - Vehicle driving force control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vehicle driving force control device, and more particularly to a device for obtaining a vehicle driving force corresponding to a gradient of a traveling road.

[0002]

2. Description of the Related Art Conventionally, there has been one in which, for example, a shift characteristic is controlled so as to obtain an optimum characteristic according to a gradient of a road (Japanese Patent Publication No. 59-8698).
(See JP-A-8-219242). These are for determining whether the road is a flat road or an uphill road, switching the shift map, and continuously correcting the speed change ratio according to the slope of the road surface during uphill traveling so that the acceleration does not become dull due to the slope. .

[0003]

However, in the case of changing the driving force characteristic of a flat road to the driving force characteristic corresponding to an uphill slope, if the gear ratio control is performed regardless of the amount of change in the road surface slope, it is desirable. I can't get a sense of acceleration.

For example, it is conceivable that the driving force may be increased by a fixed amount so as not to slow down the sense of acceleration when approaching an uphill road from a flat road. In this case, since the switching speed of the driving force at the time of changing the road surface slope is adapted to correspond to the steep uphill road, the increase in the driving force is unsatisfactory when approaching a gentle uphill road. It feels like a lack of acceleration. On the contrary, if the switching speed of the driving force when the road surface slope is changed is adapted to correspond to the gentle uphill road, the driving force increases excessively when approaching a steep uphill road. It is felt as a thing and a feeling of bulging occurs.

Therefore, the present invention adjusts the rate of change (= the amount of change per unit time) of the target driving force in accordance with the amount of change in the road surface slope when approaching from a flat road to a slope road. The purpose is to obtain the desired acceleration feeling regardless of the slope of the road when approaching the road.

[0006]

As shown in FIG. 14, a first invention is a means 1 for detecting an accelerator operation amount, a means 2 for detecting a vehicle speed, and the detected accelerator operation amount and a vehicle. Means 3 for calculating the target driving force of the vehicle on the flat road according to the speed as the normal target driving force, means 4 for detecting the weight gradient resistance (force), the detected weight gradient resistance and the normal target driving Means 5 for calculating the target driving force of the vehicle corresponding to the force as the gradient corresponding target driving force, and the changing speed of the gradient corresponding target driving force is adjusted according to the change of the calculated gradient corresponding target driving force, and the adjustment A means 6 for calculating the determined target driving force corresponding to the gradient as a final target driving force and a means 7 for realizing the final target driving force are provided.

According to a second aspect of the present invention, in the first aspect, the adjustment of the changing speed of the gradient corresponding target driving force is changed to a side where the gradient corresponding target driving force becomes large and the change amount is large in an area. This is to reduce the ratio of the changing speed of the final target driving force to the amount.

According to a third aspect of the present invention, in the first aspect, when the rate of change of the gradient-corresponding target driving force is adjusted, when the change of the gradient-corresponding target driving force is within a predetermined range near zero,
The rate of change of the final target driving force is set to zero.

According to a fourth aspect of the present invention, in any one of the first to third aspects, the gradient-corresponding target driving force calculation means 5 sets the weight gradient resistance RFORCE to 100% and corrects the driving force by a percentage less than this. Means for calculating the amount ΔRFORCE, and the calculated driving force correction amount ΔRFORCE is used as the normal target driving force tTd. The target driving force tTd corresponding to the gradient is the value added to n c and means.

According to a fifth aspect of the present invention, in the fourth aspect, the driving force correction amount ΔRFORCE is 30% to 70% of the magnitude of the weight gradient resistance RFORCE.

According to a sixth aspect of the present invention, in the fourth aspect, the ratio of the driving force correction amount ΔRFORCE to the weight gradient resistance RFORCE is a value that decreases as the weight gradient resistance RFORCE increases.

In the seventh invention, any one of the first to third inventions
In one of the inventions, the target driving force calculator for the gradient is provided.
Step 5 has a certain weight gradient resistance RFORCE which is not a flat road S
The percentage value below this is defined as 100%
Normal target driving force tTd Target drive equivalent to the value added to n
Forces corresponding to the gradient Reference target driving force tTd preset as up
Means, the detected weight gradient resistance RFORCE and the predetermined
Weight Gradient Resistance RFORCE A method to calculate the interpolation coefficient β0 from S and
Stage and the gradient-corresponding reference target using this interpolation coefficient β0.
Driving force tTd up and the normal target driving force tTd Interpolate n and
The target driving force tTd means to compute as c
Consists of.

As shown in FIG. 15, an eighth aspect of the invention is a means 1 for detecting an accelerator operation amount, a means 2 for detecting a vehicle speed, and a flattening according to the detected accelerator operation amount and the vehicle speed. The target drive force of the vehicle on the road is the normal target drive force.
tTd Means 3 for calculating as n and a predetermined weight gradient resistance RFORCE which is not a flat road If S is 100%, the value of the percentage less than this is the normal target driving force tTd. The target driving force corresponding to the value added to n is the reference target driving force tT corresponding to the gradient.
d means 141 for setting as up, means 4 for detecting the weight gradient resistance (force), and this detected weight gradient resistance RFORCE
And the prescribed weight gradient resistance RFORCE Interpolation coefficient β0 from S and
And means 143 for adjusting the changing speed of the interpolation coefficient in accordance with the change in the calculated interpolation coefficient β0 and calculating the adjusted interpolation coefficient as the final interpolation coefficient β.
And using the final interpolation coefficient β, the gradient-corresponding reference target driving force tTd up and the normal target driving force tTd A means 144 for calculating a value obtained by interpolating n and the final target driving force tTd,
And means 7 for realizing this final target driving force.

According to a ninth aspect of the invention, in the eighth aspect, the adjustment of the changing speed of the interpolation coefficient is changed to the side where the interpolation coefficient β0 becomes large, and the final interpolation for the changing quantity is made in a region where the changing quantity is large. This is to reduce the rate of change rate Δβ of the coefficient.

According to a tenth aspect of the present invention, in the eighth aspect, when the change rate of the interpolation coefficient is adjusted within a predetermined range near zero, the change rate Δβ of the final interpolation coefficient is set to It is to zero.

In an eleventh aspect of the invention, in any one of the first to tenth aspects of the invention, the means 4 for detecting the weight gradient resistance is means for detecting the absolute position of the vehicle, and the vehicle based on the detected value. And a means for estimating the weight gradient resistance from the estimated road gradient and means for estimating the gradient of the road on which the road exists.

In a twelfth aspect of the present invention, in any one of the first to tenth aspects of the present invention, the means 4 for detecting the weight gradient resistance is a means for calculating a drive shaft rotational force, and a flattening according to the vehicle speed. A means for calculating a reference running resistance on the road as a reference running resistance; a means for detecting the acceleration of the vehicle; a means for estimating the acceleration resistance (force) of the vehicle based on the detected acceleration; And means for estimating a value obtained by subtracting the reference running resistance and the acceleration resistance from the generated drive shaft rotational force as the weight gradient resistance.

[0018]

According to the first aspect of the invention, the speed of change of the target driving force is adjusted according to the change of the target driving force (corresponding to the change of the road surface gradient), so that the vehicle approaches the slope road from the flat road. The desired acceleration feeling can be obtained regardless of the road gradient.

According to the second aspect of the invention, in a region where the gradient is large when the road is uphill from a flat road, the gradient-corresponding target driving force changes to a larger side and the amount of change is large, so that change. The rate of change of the final target driving force with respect to the amount is reduced, and according to the ninth aspect, the interpolation coefficient changes to the larger side and the amount of change is large. Is reduced (that is, the rate of change of the final target driving force is suppressed when the road surface gradient is large when approaching a graded road in both inventions), so that, for example, the moment when a steep uphill grade is approached The driving force is suddenly corrected and you will not feel a rush.

According to the third and tenth aspects of the present invention, the driving force is not greatly corrected for a minute change in the road surface slope that the driver does not feel, and the slope is estimated (or Even if the target driving force slightly changes due to a slight gradient estimation variation caused by noise when performing measurement), the change in the final target driving force can be suppressed.

In the fourth invention, the weight gradient resistance is set to 100.
To calculate a driving force correction amount ΔRFORCE that is less than this as a percentage, it is sufficient to multiply the weight gradient resistance by a coefficient of less than 1. That is, the target driving force on a flat road can be obtained by only having one coefficient for the weight gradient resistance.
Since the (normal target driving force) can be converted into the target driving force corresponding to the gradient, according to the fourth invention, it is not necessary to have a target map different from usual such as a high output mode which corresponds to the gradient unlike the conventional device. It is possible to prevent the ROM capacity from increasing. Further, it is possible to easily perform characteristic tuning by changing the gradient resistance coefficient.

According to the fifth aspect of the invention, the driving force correction can be assisted most comfortably when traveling uphill, so that not only does the driver feel neither insufficient acceleration nor a sense of tension when traveling uphill,
You can always get a natural feeling of acceleration.

According to the sixth aspect of the present invention, it is possible to produce a natural sense of acceleration while always reducing the driver's discomfort no matter how the gradient changes.

According to the seventh aspect of the present invention, since the means for presetting the gradient-corresponding reference target driving force is provided, it is possible to easily build in various constraint conditions. For example, it is possible to set the gradient-corresponding reference target driving force so that the driving force cannot be actually output due to the output torque characteristic of the mounted engine. Also, for example, another driving range (Tatoba sports mode)
By setting the gradient-corresponding reference target driving force to be smaller than the target driving force in, it is possible to avoid accelerating or decelerating regardless of the driver's intention when switching to the sports mode. Alternatively, it is possible to always change to the acceleration side as expected by the driver.

In the eighth invention, instead of adjusting the changing speed of the target driving force, the changing speed of the interpolation coefficient used for the interpolation calculation is adjusted, so that the modularization of each means is simplified and the driving force control is performed. When the controller with CPU is used, the processing load on the CPU can be reduced. For example, when an external sensor for detecting the weight gradient resistance is used, it is often the case that another CPU process is performed externally in order to transmit the sensor signal to the CPU that controls the driving force. According to the invention of claim 8, from the calculation of the interpolation coefficient to the adjustment of the interpolation coefficient, the CP for signal processing of the external sensor is provided.
It becomes possible to process with U.

In the eleventh aspect of the invention, since the road gradient at the position where the vehicle is present can be estimated based on the map information and the absolute position information from the satellite which is held in advance, driving due to changes in the vehicle state such as tire puncture and deterioration over time. The road gradient can always be accurately detected without being affected by changes in force characteristics.
In addition, it is possible to estimate not only the roads that currently exist but also the roads that are planned to travel ahead, so it is possible to read the slope ahead of time and correct the driving force. It becomes possible to correct the driving force.

In the twelfth invention, it is not necessary to provide a new sensor for detecting the weight gradient resistance, so that the weight gradient resistance can be estimated very inexpensively.

[0028]

1 is a block diagram of the entire control system.

The output of the engine 101 is transmitted to drive wheels (not shown) via an automatic transmission 103 with a built-in torque converter. The automatic transmission here is a stepped automatic transmission that applies a planetary gear and a clutch member. The present invention is not limited to a stepped transmission, but the present invention can be applied to a V-belt type or toroidal type continuously variable transmission.

In the intake passage of the engine 101, a so-called electronically controlled throttle device 102 for opening / closing a throttle valve by a motor or the like is provided. The amount of air taken into the engine 101 is adjusted by the opening of the throttle valve. , The output torque of the engine is controlled.

In order to drive the above electronically controlled throttle device 102, a throttle control module (hereinafter TC
M) 51. The TCM51, which receives the throttle valve opening command from the powertrain control module (PCM) 50, converts the throttle valve opening command to a motor drive voltage and outputs it to the motor, and the actual throttle valve opening is PCM50. The motor drive voltage (throttle valve opening) is feedback-controlled so as to coincide with the opening command from.

An accelerator operation amount signal (an accelerator pedal depression amount), an accelerator operation amount signal from the sensor 105, a brake operation signal from the brake operation switch 106, a select range signal from the range selection lever 107 of the automatic transmission, etc. are input. In the PCM50, based on these signals, engine control (for example, mainly control of the fuel supply amount to the engine 101 and ignition timing), automatic transmission control (gear position control to the automatic transmission 103, hydraulic control), braking force Each control of control (brake hydraulic pressure control to the brake actuator 104 for each wheel) is performed.

On the other hand, 111 is a camera for photographing the situation in front of the vehicle as an image. The signal from the camera 111 is used by the image processing device 53 for the road situation in front and the vehicle situation.
It is processed as obstacle information and the like and transmitted to the external environment information processing module 52.

Reference numeral 113 denotes a GPS antenna 113 which receives a signal from a satellite, and the information from the satellite is transmitted to the position information processing device 54 in order to grasp the current position of the vehicle. Map information that incorporates geographical attributes and road information in advance
In the position information processing device 54 stored as a recording medium such as a CD-ROM, the external environment information processing module 52 collects the information of the region currently existing from this information and the signal from the GPS antenna 113. Send to.

In the external environment information processing module 52, the current environment of the vehicle is appropriately collected and transmitted to the PCM 50, and the PCM 50 receives the signal and controls the output of the engine 101 and the shift of the automatic transmission 103. To do. On the contrary, PCM50
The output torque information of the engine 101, the gear position information of the automatic transmission 103, the signal state from the accelerator opening sensor 105, the brake operation switch 106, and the like are transmitted to the external environment information processing module 52. In the external environment information processing module 52,
When receiving this signal, the accuracy of the judgment of the external environment may be improved, or the psychological state of the driver may be estimated.

Conventionally, there has been a conventional control in which the shift characteristic is changed so as to obtain the optimum characteristic according to the gradient of the traveling road.

However, when changing from the driving force characteristic of a flat road to the driving force characteristic corresponding to a climbing slope, if the gear ratio control is performed regardless of the amount of change in the road surface gradient, a desired acceleration feeling can be obtained. Absent. For example, when approaching an uphill road from a flat road, it is conceivable that the driving force is increased by a certain amount so as not to slow down the feeling of acceleration. In this case, since the switching speed of the driving force at the time of changing the road surface slope is adapted to correspond to the steep uphill road, the increase in the driving force is unsatisfactory when approaching a gentle uphill road. It feels like a lack of acceleration. On the contrary, if the switching speed of the driving force when the road surface slope is changed is adapted to correspond to the gentle uphill road, the driving force increases excessively when approaching a steep uphill road. It is felt as a thing and a feeling of bulging occurs.

To deal with this, in the first embodiment of the present invention, when the driving force characteristic of the flat road is changed to the driving force characteristic corresponding to the uphill gradient, the change of the target driving force corresponding to the change of the road surface gradient is performed. Adjust the speed (= amount of change per unit time).

This control performed by the PCM 50 will be described with reference to the block diagram of FIG.

In the normal target driving force setting means 12 to which the accelerator operation amount APO detected by the accelerator operation amount sensor 105 and the vehicle speed VSP detected by the vehicle speed detecting means 11 are input, according to these values. , The target value of the vehicle driving force when traveling on a flat road is the normal target driving force tTd Set as n.

The gradient-corresponding target driving force calculation means 15 comprises a driving force correction amount calculation means (comprising multiplication means) 16 and a driving force correction means (comprising addition means) 17. The weight gradient resistance RFORCE detected by the weight gradient resistance detection means 14 is input to the driving force correction amount calculation means 16, and this weight gradient resistance RFORCE is input.
The driving force correction amount ΔRFORCE (= α × RFORCE) is obtained by multiplying CE by the gradient resistance coefficient α (where 0 <α <1), and the value of the correction amount ΔRFORCE is calculated by the driving force correction means 17 as described above. Target driving force tTd The target driving force tTd corresponding to the gradient is added to n c (= tTd n + ΔRFORCE) is calculated.

A feeling of acceleration that the driver can enjoy on a flat road
Normal target driving force tTd n, uphill road
Drive so that the driver can get a sense of acceleration
By calculating each force correction amount ΔRFORCE,
You will always get a pleasant acceleration regardless of the road or climbing road.
Be done.

In this case, the target driving force on the flat road can be converted into the target driving force corresponding to the gradient by only having one gradient resistance coefficient α for the weight gradient resistance RFORCE, so that the gradient driving can be performed like the conventional device. It is not necessary to have an unusual target map such as a certain high output mode, and it is possible to prevent the ROM capacity from increasing. Further, characteristic tuning can be easily performed by changing the gradient resistance coefficient α.

The target driving force tT corresponding to the gradient thus obtained
d c is converted into the final target driving force tTd via the target driving force change speed adjusting means 20.

The target driving force change speed adjusting means 20 comprises a target driving force change amount setting means 21, an adding means 22, and a delay calculating means 23.

Target drive force tTd corresponding to the above gradient In the target driving force change amount setting means 21 to which c is input, a change amount ΔTd of the target driving force per unit time (amount of change per 10 msec when this block is processed every 10 msec) is set. For example, the final target driving force obtained 10 msec before is tTd _-1
Then, the target driving force tTd corresponding to the gradient obtained this time c and this t
The variation ΔTd of the target driving force per unit time is obtained by searching a predetermined map from the deviation from Td ₋₁ (change of the target driving force).

In the adding means 22, the value of ΔTd is tT which is the previous value.
By adding to d ₋₁ , the final target driving force tTd (= tTd ₋₁ + ΔTd) which is the current value is obtained. The delay calculation means 23 becomes z ⁻¹ when expressed in a discrete time system, and tT
By multiplying d by this z ⁻¹ , one sample period before (10 mse
The value of tTd ₋₁ (= tTd × z ⁻¹ ) which is the value of c) is obtained.

As shown in the figure, the characteristic of ΔTd is the deviation (tTd c−tTd ₋₁ ) is proportional to the deviation within a predetermined value, and when the deviation exceeds the predetermined value, the ratio of the amount ΔTd of change in target driving force per unit time to the deviation is reduced. Change ΔTd of the target driving force per unit time to the above-mentioned deviation tTd which is the change of the target driving force. c−t
By setting it corresponding to Td _-1 (this deviation represents the amount of change in the road surface slope when approaching a graded road from a flat road), the switching speed of the driving force when approaching a graded road from a flat road is set. Make adjustments.

FIG. 3 is a flowchart constructed corresponding to the block diagram of FIG.

Although there are some parts that overlap with those described with reference to FIG. 2, regardless of the description, FIG.
Execute every 10 msec.

In step 1, the accelerator operation amount APO, the vehicle
Load both speed VSP, weight gradient resistance RFORCE, out of which
Normal target drive according to accelerator operation amount APO and vehicle speed VSP
Force tTd Set n in step 2. Where the normal eye
Target driving force tTd n is the vehicle driving force index when driving on a flat road.
It is a standard price.

In step 3, the weight gradient resistance RFORCE is multiplied by the gradient resistance coefficient α (where 0 <α <1) to obtain the driving force correction amount ΔRFORCE (= α × RFORCE), and this value ΔRFORCE is calculated in step 4 above. Normal target driving force tTd By adding to n, the target driving force tTd corresponding to the gradient c (= tTd n +
Calculate ΔRFORCE).

In step 5, this calculated Td A predetermined map is searched from the deviation between c and the last value of the final target driving force, tTd _-1 , to find the change amount ΔTd of the target driving force per unit time, and this value ΔTd is determined in step 6 as the final target driving force. The final target driving force tTd (= tTd ₋₁ + ΔTd) of this time is obtained by adding tTd ₋₁ which is the previous value of

As described above, in the first embodiment of the present invention,
When changing from the target driving force (normal target driving force) on a flat road to the target driving force corresponding to the climbing slope, the deviation Td which is the change in the target driving force Since the change amount ΔTd (change speed of the target driving force) of the target drive force per unit time is adjusted according to c−tTd ₋₁ (corresponding to the change of the road surface gradient), it is possible to change from the flat road to the slope road. Regardless of the road slope when approaching,
You can get the acceleration you want.

Further, in a region where the gradient is large when the road is uphill from a flat road, the target drive force corresponding to the gradient changes to a larger side and the amount of change is large. Since the rate of change in force is reduced (that is, the rate of change in final target driving force is suppressed if the road surface slope is large when approaching a grade), for example, the moment when approaching a steep uphill grade The driving force is suddenly corrected and you will not feel a rush.

FIG. 4 shows the gradient resistance coefficient calculating means 31 of the second embodiment.

In the first embodiment, the gradient resistance coefficient α is a constant value, whereas in the second embodiment, the gradient resistance coefficient α is a function of the weight gradient resistance RFORCE, that is, the weight gradient resistance RF.
It is made smaller as the ORCE becomes larger.

Here, the greater the weight gradient resistance, the more α
The value of is made smaller because the driver recognizes the gradient more strongly as the weight gradient resistance increases. That is, when the grade is gentle, the driver does not notice the grade very much, so the amount of accelerator operation does not change much from that on a flat road, so unless the ratio of the driving force correction amount ΔRFORCE to the weight gradient resistance is increased, insufficient acceleration is felt. I tend to. On the other hand, as the gradient becomes larger, the driver recognizes the gradient and deliberately depresses the accelerator pedal deeply.Therefore, even if the ratio of the driving force correction amount ΔRFORCE to the weight gradient resistance is small compared to a gentle gradient, the driver accelerates. Never feel short. Therefore, if α is given so that the ratio of the driving force correction amount ΔRFORCE to the weight gradient resistance becomes smaller as the weight gradient resistance becomes larger, no matter how the gradient changes, the driver will feel less discomfort. , Can always produce a natural sense of acceleration.

Further, the gradient resistance coefficient α is changed between 30% and 70% because the driving force correction can be assisted most comfortably when driving uphill is 30% of the weight gradient resistance.
This is because the range is up to 70%. As a result, not only does the vehicle not feel insufficient acceleration or a sense of tension when traveling uphill, but it also provides a natural feeling of acceleration.

FIGS. 5 and 6 show a third embodiment, which replaces FIGS. 2 and 3 of the first embodiment, respectively. Figure 5
2 are designated by the same reference numerals, and in FIG. 6, the same portions as those in FIG. 3 are designated by the same step numbers.

2 will be mainly described. The difference from FIG. 2 is the content of the gradient-corresponding target driving force calculating means 41, which is the gradient-corresponding reference target driving force setting means.
42, a division means 43, and a target driving force interpolation calculation means 44.

Of these, the gradient-corresponding reference target driving force setting procedure
At step 42, a predetermined value is calculated from the accelerator operation amount APO and the vehicle speed VSP.
Gradient corresponding reference target driving force by searching the map
tTd up is required. Here, the gradient-corresponding reference target driving force t
Td up is a predetermined weight gradient resistance RFORCE that is not a flat road
S is 100%
Normal target driving force tTd Target drive equivalent to the value added to n
Power, specifically the normal target driving force tTd pair n
Then

[0063]

[Equation 1] tTd up ＝ tTd n + α × R FORCE It is predetermined to be S.

On the other hand, in the dividing means 43, the weight gradient resistance RFOR
CE (detection value) is the prescribed weight gradient resistance RFORCE By dividing by S, that is

[0065]

[Equation 2] β0 = RFORCE / RFORCE The interpolation coefficient β0 (dimensionless number) is calculated by the equation of S, and the target driving force interpolation calculation means 44 is calculated using this interpolation coefficient β0.

[0066]

[Equation 3] tTd c = β0 × tTd up + (1-β0) × tTd The target driving force tTd corresponding to the slope is calculated by the interpolation formula of n. c is required.

For example, RFORCE = RFORCE In the case of S, β0 = 1 from the equation 2 and then tTd from the equation 3 c ＝ tTd up
Becomes

Target driving force tT corresponding to the gradient calculated in this way
d c is tTd in Fig. 2 Similar to c, it is converted into the final target driving force tTd via the target driving force change speed adjusting means 20.

FIG. 6 is a flowchart configured corresponding to FIG. 6 are different from FIG. 3 in steps 11, 12, and 13.

Here again, although there is a portion overlapping with that described with reference to FIG. 5, regardless of the explanation, in step 11, the normal target driving force tTd n, gradient resistance coefficient α, standard weight gradient resistance RFORCE Using S, the slope-corresponding reference target driving force tTd ask for up.

In step 12, the weight gradient resistance RFORCE (detection value) and the reference weight gradient resistance RFORCE From S, the interpolation coefficient β0 is calculated by the above equation 2, and the interpolation target β0 is used in step 13 by the above equation 3 to obtain the target driving force tTd corresponding to the gradient. ask for c.

As described above, in the third embodiment, the gradient-corresponding reference target driving force tTd Since it has a means for setting up in advance, it is possible to easily create it for various constraint conditions. For example, the gradient-corresponding reference target driving force tTd should It is possible to set up. Further, for example, the target driving force tTd corresponding to the gradient is smaller than the target driving force in the other driving range (Tatoba sports mode). By setting up, it is possible to avoid accelerating or decelerating regardless of the driver's intention when switching to the sports mode. Alternatively, it is possible to always change to the acceleration side as expected by the driver.

7 and 8 show a fourth embodiment, which replaces FIGS. 5 and 6 of the third embodiment, respectively. Figure 7
5, the same parts as those in FIG. 5 are given the same reference numerals, and the same parts in FIG. 8 as those in FIG. 6 are given the same step numbers.

As shown in FIG. 7, the fourth embodiment is provided with an interpolation coefficient changing speed adjusting means 60 in place of the target driving force changing speed adjusting means 20 of FIG. The means 60 is an interpolation coefficient change amount setting means 61, an adding means
62 and delay calculation means 63.

Of these, the interpolation coefficient change amount setting means 61 to which the interpolation coefficient β0 is input changes in the interpolation coefficient per unit time (10 msec when this block is processed every 10 msec).
The amount of change per hit) Δβ is set. For example, if the final interpolation coefficients obtained before 10msec and beta _-1, (change of the interpolation coefficients) deviation between the interpolation coefficients β0 Toko of beta _-1 determined time
By searching a predetermined map from, the change amount Δβ of the interpolation coefficient per predetermined time is calculated.

In the adding means 62, the change amount Δβ per predetermined time set in this way is added to the previous value β ₋₁ , so that the final interpolation coefficient β (= β ₋₁ +
Δβ) is required.

As shown in the figure, the characteristic of Δβ is such that the deviation (β ₀ -β _-1 ) shown on the horizontal axis is proportional to the deviation within a predetermined value, and when the deviation exceeds the predetermined value, This is a value obtained by reducing the ratio of the amount of change Δβ of the interpolation coefficient per unit time. In this case as well, the variation Δβ of the interpolation coefficient per unit time is defined as the above-mentioned deviation β0−β
_-1 (this deviation represents a change in slope when approaching a graded road from a flat road), and as a result, the rate of change of the driving force is adjusted as in the third embodiment. Of.

On the other hand, the target driving force interpolation calculating means 66 of the gradient corresponding target driving force calculating means 65 uses the final interpolation coefficient β thus obtained,

[0079]

[Formula 4] tTd = β × tTd up + (1-β) × tTd The final target driving force tTd can be obtained from the interpolation calculation formula of n.

FIG. 8 is a flowchart corresponding to the block diagram of FIG.

In FIG. 8, steps 21, 22, and 23 are different from FIG. 6 of the third embodiment.

Here again, there is a portion overlapping with that described with reference to FIG. 7. However, in any case, in step 21, the interpolation coefficient β 0 obtained this time and β ₋ which is the final interpolation coefficient obtained 10 msec before are obtained. _The amount of change Δβ of the interpolation coefficient per unit time is obtained by searching a predetermined map from the deviation from ₁ (change of the interpolation coefficient). This Δβ is step 2
The final interpolation coefficient β (= β ₋₁ + Δβ), which is the current value, is obtained by adding the previous value β ₋₁ in step 2, and this final interpolation coefficient β is used in step 23 to calculate the above equation 4 The final target driving force tTd is calculated by.

As described above, in the fourth embodiment, instead of adjusting the changing speed of the target driving force, the normal target driving force tTd n
And reference target driving force for slope tTd Since it is configured to adjust the changing speed of the interpolation coefficient β used for the interpolation calculation with up, modularization of each means is simplified, and when the driving force control is performed by the control module (PCM50) equipped with a CPU, the The processing load on the CPU can be reduced. For example, when an external sensor for detecting the weight gradient resistance is used, the sensor signal is transmitted to the CPU that controls the driving force, so it is often performed externally by another CPU. According to the fourth embodiment, the signal processing CPU of the external sensor can process the means 43 and 60 for calculating the interpolation coefficient and adjusting the interpolation coefficient.

In the configuration of FIG. 2, since the target driving force change speed adjusting means 20 is connected in series, the processing speed of the means 20 determines the update speed of the target driving force. Since the dividing means 43 and the interpolation coefficient switching speed adjusting means 60 are connected in parallel to the other means 12, 42, 66, the processing speed of the means 43, 60 is changed to the means 12, 42, 66.
It can be set separately from the processing speed of.

FIG. 9 shows a fifth embodiment, which shows a method of estimating the slope of a road surface from map data including altitude.

Consider the estimation of the road gradient at the position of the vehicle 71 shown in FIG. In this case,
If the map information is divided into grids as shown in the figure and the elevation data of each grid point (indicated by black circles) is stored,
Using the elevation data (a, b, c, d) of the four grids of the section in which 71 exists, the average gradients in the X-axis direction and the Y-axis direction of that section are

[0087]

## EQU00005 ## Average gradient in the X-axis direction = (d-b + ca) / 2L Average gradient in the Y-axis direction = (ab + c-d) / 2L However, since L is given by the formula of the lattice spacing, If the vehicle 71 is traveling counterclockwise with respect to the X-axis direction in the direction of the angle ξ,

[0088]

[Equation 6] tan Θ = {(d-b + ca) / 2L} × cos ξ + {(a-b + c-
The road gradient Θ at the position where the vehicle 71 exists can be obtained from the expression d) / 2L} × sin ξ.

From this road gradient Θ to the weight gradient resistance RF
To obtain the ORCE, refer to Japanese Patent Application Laid-Open No. 8-219242

[0090]

[Formula 7] RFORCE = m × g × sin Θ However, m: vehicle weight g: Gravity acceleration The following equation may be used.

Here, the case of the map information in which the elevation data is stored in a grid pattern has been described, but the present invention is not limited to this, and the elevation data may be stored at a point on the road or the inclination of the road may be stored. It is also possible to estimate the road gradient by storing the value at a point on the road.

As described above, in the fifth embodiment, the road gradient at the position where the vehicle exists is estimated based on the map information that is held in advance and the absolute position information from the satellite or the like. The road gradient can be accurately detected without being affected by changes in driving force characteristics due to changes in vehicle conditions.

Further, not only the existing roads but also the roads to be traveled ahead can be estimated, so that the driving force can be corrected by reading the roads in advance, and the driver can further respond. It is possible to correct the driving force with good performance. Normally, even if an attempt is made to estimate the road gradient from the output, driving force and vehicle acceleration, it will not completely match the actual gradient (that is, there will be a deviation) due to calculation delays or vehicle driving force transmission delays. This gap can be avoided by reading ahead.

FIG. 10 shows a sixth embodiment, in which the drive shaft rotational force is calculated, and the weight running resistance is estimated by adding the reference running resistance and the acceleration resistance on a flat road. It is a thing.

First, the drive shaft torque calculating means 81 is mainly composed of an engine output shaft torque calculating means 82, a torque converter torque amplification ratio calculating means 83, and a drive system loss torque estimating means 84. Of these, in the engine output shaft torque calculation means 82, the engine fuel injection amount Tp and the engine speed EN
The output shaft torque Te of the engine is obtained by searching a predetermined map from GREV. In the torque amplification ratio calculation means 83 of the torque converter, the ratio between the engine speed ENGREV and the transmission input shaft speed INPREV (output shaft speed of the torque converter) is calculated as the gear ratio SLPRTO, and a predetermined map is calculated from this value. By searching,
The torque amplification ratio TAURTO of the torque converter is required.
The drive system loss torque estimating means 84 obtains the loss torque LOSSTRQ by searching a predetermined map from the operating oil pressure TGTPRS that has the largest influence on the drive system loss torque.

In the multiplication means 85, the output shaft torque of the engine
Te is multiplied by the torque amplification ratio TAURTO of the torque converter to obtain the primary shaft output torque Tin (= Te × TAURTO), and the multiplication means 86 and the addition means 87

[0097]

[Equation 8] Tsec = Tin × RATIO−LOSSTRQ However, the output shaft torque (= driving shaft rotational force) Tsec of the drive shaft is calculated by the formula of RATIO: input / output speed ratio of the transmission.

On the other hand, the reference running resistance calculating means 91 retrieves a predetermined map from the vehicle speed VSP to determine the reference running resistance (reference running resistance on a flat road) RLDT.
RQ is required.

The acceleration detecting means 92 obtains the vehicle acceleration GDATA from the difference of the vehicle speed VSP, and the acceleration resistance estimating means 9
In 3, the estimated acceleration resistance AccTRQ on the output shaft is obtained by multiplying the vehicle acceleration GDATA by the equivalent weight Iv of the vehicle viewed from the output shaft.

The output shaft torque Tsec of the drive shaft, the reference running resistance RLDTRQ, and the estimated acceleration resistance thus obtained are obtained.
Using AccTRQ, in the weight gradient resistance estimating means 94,

[0101]

[Formula 9] RFORCE = Tsec-RLDTRQ-AccTRQ The weight gradient resistance RFORCE is calculated by the following equation.

Although the vehicle acceleration is estimated from the vehicle speed in FIG. 10, the vehicle acceleration may be directly detected by the acceleration sensor.

As described above, in the sixth embodiment, since it is not necessary to provide a new sensor for detecting the weight gradient resistance, the weight gradient resistance can be estimated very inexpensively.

FIG. 11 shows the target driving force change amount setting means 121 of the seventh embodiment, which is shown in FIG. 2 (first embodiment) and FIG. 5 (third embodiment).
It is replaced with the target driving force change amount setting means 21 of the embodiment).

In FIG. 11, when the change of the target driving force (value obtained by subtracting the final target driving force of a predetermined time before from the present target driving force) shown on the horizontal axis is positive and the amount of change is large, Then, the change amount of the target driving force per unit time is gently changed.

As a result, when the road surface is approaching a gradient road and the road surface slope is steep, the change in the driving force is suppressed as compared with the case where the road surface slope is gentle, and the abrupt torque is increased. Less shock.

Further, in FIG. 11, when the change in the target driving force is negative, the change amount per unit time is made substantially proportional to the change in the target driving force even in the region where the change amount is large.
The case where the change in the target driving force is negative and the amount of change is large is the case where the change in the road surface slope is rapid when the climbing slope becomes gentle. As the driver becomes insensitive to the torque step at the time, as a general rule, the target driving force switching speed is given in proportion to the change of the target driving force (change of the road surface gradient when the climbing gradient becomes gentle). It was done like this.

FIG. 12 shows the interpolation coefficient change amount setting means 131 of the eighth embodiment, which is replaced by the interpolation coefficient change amount setting means 61 of FIG. 7 (fourth embodiment).

In FIG. 12, when the change (β ₀ -β _-1 ) of the interpolation coefficient shown on the horizontal axis is near zero, the change amount of the interpolation coefficient per unit time is set to zero.

This is to cope with a case where the estimated gradient slightly changes due to noise or the like when traveling on a flat road. For example, if the estimated gradient slightly changes due to noise or the like, the weight gradient resistance calculated based on this estimated gradient slightly changes, and the interpolation coefficient β0 obtained from this weight gradient resistance slightly changes. Therefore, if the amount of change Δβ per unit time is calculated in response to such a minute change in the interpolation coefficient β0, a slight change in driving force will occur even when the vehicle is traveling on a flat road.

On the other hand, according to the characteristics of FIG. 12, even when the interpolation coefficient β0 slightly changes due to the influence of the estimated gradient such as noise, the final interpolation coefficient β does not change. Therefore, it is possible to suppress a minute change in driving force that does not meet the intention when traveling on a flat road.

FIG. 13 shows a target driving force realizing means 151 of the ninth embodiment.

The target driving force realization means 151 comprises a transmission input / output ratio control means 152, a transmission input / output ratio realization means 153, a target engine output torque calculation means 154, and an engine output torque realization means 155.

First, the target driving force tTd corresponding to the gradient and the vehicle speed V
The transmission input / output ratio control means 152 to which SP is input obtains the target input / output speed ratio tRATIO of the transmission by searching a predetermined map from these values. here,
A map for obtaining the target input / output rotation speed ratio tRATIO is used for both parameters, but the map is not limited to this. For example, in the input / output ratio control of the transmission, since the target value of the input shaft speed is usually obtained, the target input / output speed ratio tRATIO is calculated in relation to the vehicle speed VSP after obtaining the target input shaft speed. May be asked.

The target input / output rotation speed ratio tR thus obtained
ATIO is realized by the transmission input / output ratio realizing means 153.

The target engine output torque calculating means 154 calculates the target engine output torque tTe by dividing the gradient corresponding target driving force tTd by the input / output rotation speed ratio RATIO realized by the transmission 103. Then, in the engine output torque realizing means 155 composed of the engine torque control means 156 and the engine 101, the throttle operation amount, the fuel injection amount, the ignition timing, etc. are controlled by the engine torque control means 156 in order to realize the target engine torque tTe. A command (command value such as throttle operation amount, fuel injection amount, ignition timing, etc.) from the engine torque control means 66 is sent to the engine 101.

As described above, in the ninth embodiment, in order to realize the gradient-corresponding target driving force, the target input / output of the transmission having a slow response is determined when the target input / output rotational speed ratio of the transmission and the target engine output torque are determined. Since the rotation speed ratio is determined first, the gradient-corresponding target driving force can be realized with high responsiveness.

In the embodiment shown in FIG. 11, the case of the target driving force has been described, but the same can be applied to the interpolation coefficient. For example, in the characteristics of FIG. 11, the target driving force may be replaced with the interpolation coefficient. Similarly,
In the embodiment shown in FIG. 12, the case of the interpolation coefficient has been described, but the same can be applied to the target driving force. For example, in the characteristics of FIG. 12, the interpolation coefficient may be replaced with the target driving force.

[Brief description of drawings]

FIG. 1 is a control system diagram of the entire vehicle of the present invention.

FIG. 2 is a block diagram showing processing performed by PCM50.

FIG. 3 is a flowchart corresponding to the block diagram of FIG.

FIG. 4 is a block diagram of a second embodiment.

FIG. 5 is a block diagram showing processing performed by a PCM 50 according to a third embodiment.

FIG. 6 is a flowchart corresponding to the block diagram of FIG.

FIG. 7 is a block diagram showing processing performed by a PCM 50 of the fourth embodiment.

FIG. 8 is a flowchart corresponding to the block diagram of FIG.

FIG. 9 is a road map for explaining a road gradient calculation according to the fifth embodiment.

FIG. 10 is a block diagram of a sixth embodiment.

FIG. 11 is a block diagram of a seventh embodiment.

FIG. 12 is a block diagram of an eighth embodiment.

FIG. 13 is a block diagram of a ninth embodiment.

FIG. 14 is a diagram corresponding to claims of the first invention.

FIG. 15 is a diagram corresponding to a claim of the eighth invention.

[Explanation of symbols]

12 Normal target driving force calculation means 15 Target driving force calculation means for slope 20 Target driving force change speed adjusting means 21 Target driving force change amount setting means 41 Target Driving Force Calculation Means for Gradient 44 Target driving force interpolation calculation means 50 PCM 60 Interpolation coefficient changing speed adjusting means 61 Interpolation coefficient change amount setting means

─────────────────────────────────────────────────── ─── Continued Front Page (51) Int.Cl. ⁷ Identification FI F02D 41/04 310 F02D 41/04 310C F16H 61/02 F16H 61/02 // F16H 59:18 59:18 59:44 59: 44 59:66 59:66 (72) Inventor Hiroro Nishijima 2 Takaracho, Kanagawa-ku, Yokohama, Kanagawa Nissan Motor Co., Ltd. (56) Reference JP-A-8-219242 (JP, A) JP-A-2- 42148 (JP, A) JP 10-9374 (JP, A) JP 8-72591 (JP, A) JP 5-149163 (JP, A) JP 4-219433 (JP, A) JP 10-1018 (JP, A) JP 62-111151 (JP, A) JP 9-86224 (JP, A) JP 59-8698 (JP, B2) (58) Fields investigated (Int.Cl. ⁷ , DB name) F02D 29/00-29/06 F02D 41/00-45/00 B60K 41/00-41/28 B60K 31/00

Claims (12)

(57) [Claims] 1. A means for detecting an accelerator operation amount, a means for detecting a vehicle speed, and a target driving force of a vehicle on a flat road corresponding to the detected accelerator operation amount and the vehicle speed, as a normal target driving force. Means for calculating the weight gradient resistance, means for calculating the target driving force of the vehicle according to the detected weight gradient resistance and the normal target driving force as a gradient corresponding target driving force, A means for adjusting the rate of change of the gradient-corresponding target driving force according to the change of the gradient-corresponding target driving force, and calculating the adjusted gradient-corresponding target driving force as the final target driving force, and realizing this final target driving force. And a means for controlling the vehicle driving force. 2. The adjustment of the rate of change of the gradient-corresponding target driving force is performed by switching the final target driving force to the variation in a region where the gradient-corresponding target driving force is changed to a larger side and the variation is large. The vehicle driving force control device according to claim 1, wherein the speed ratio is reduced. 3. The adjustment of the rate of change of the gradient-corresponding target drive force sets the switching speed of the final target drive force to zero when the change of the gradient-corresponding target drive force is within a predetermined range near zero. The vehicle driving force control device according to claim 1, wherein 4. The gradient-corresponding target driving force calculating means calculates a driving force correction amount of a percentage less than the weight gradient resistance as 100%, and the calculated driving force correction amount is the normal target. The vehicle driving force control device according to any one of claims 1 to 3, further comprising a unit that sets a value added to the driving force as a gradient-corresponding target driving force. 5. The vehicle driving force control device according to claim 4, wherein the driving force correction amount is 30% to 70% of the magnitude of the weight gradient resistance. 6. The vehicle driving force control device according to claim 4, wherein the ratio of the driving force correction amount to the weight gradient resistance is a value that decreases as the weight gradient resistance increases. 7. The target driving force calculating means corresponding to the gradient corresponds to a value obtained by adding a percentage value less than 100% to a predetermined weight gradient resistance which is not a flat road and the normal target driving force. Is preset as a gradient corresponding reference target driving force, a means for calculating an interpolation coefficient from the detected weight gradient resistance and the predetermined weight gradient resistance, and the gradient corresponding reference target drive using this interpolation coefficient. 4. The vehicle driving force control device according to claim 1, further comprising means for calculating a value obtained by interpolating the force and the normal target driving force as a gradient-corresponding target driving force. . 8. A means for detecting an accelerator operation amount, a means for detecting a vehicle speed, and a target drive force for a vehicle on a flat road according to the detected accelerator operation amount and the vehicle speed. And a target driving force corresponding to a value obtained by adding a percentage value less than this to the normal target driving force as 100% as a predetermined weight gradient resistance which is not a flat road, is set as the gradient corresponding reference target driving force. Means, a means for detecting a weight gradient resistance, a means for calculating an interpolation coefficient from the detected weight gradient resistance and the predetermined weight gradient resistance, and an interpolation coefficient according to a change in the calculated interpolation coefficient. Means for adjusting the rate of change of the gradient and calculating the adjusted interpolation coefficient as a final interpolation coefficient; and using the final interpolation coefficient, the gradient-corresponding reference target driving force and the normal target driving force. A vehicle driving force control device comprising: means for calculating a value obtained by performing an interpolation calculation of and as a final target driving force; and means for realizing the final target driving force. 9. The adjustment of the changing speed of the interpolation coefficient is performed by decreasing the ratio of the changing speed of the final interpolation coefficient to the changing amount in a region where the changing amount is large and the changing amount is large. The vehicle driving force control device according to claim 8, wherein: 10. The speed of change of the interpolation coefficient is adjusted when the change of the interpolation coefficient is within a predetermined range near zero.
9. The vehicle driving force control device according to claim 8, wherein the changing speed of the final interpolation coefficient is set to zero. 11. The means for detecting the weight gradient resistance includes means for detecting an absolute position of the vehicle, and means for estimating the gradient of the road on which the vehicle is present based on the detected value from map information which has in advance. The vehicle driving force control device according to any one of claims 1 to 10, further comprising means for calculating a weight gradient resistance from the estimated road gradient. 12. A means for detecting the weight gradient resistance, a means for calculating a driving shaft rotational force, and a means for calculating a reference running resistance on a flat road according to the vehicle speed as a reference running resistance. A means for detecting the acceleration of the vehicle, a means for estimating the acceleration resistance of the vehicle based on the detected acceleration, a value obtained by subtracting the reference running resistance and the acceleration resistance from the calculated drive shaft rotational force, The vehicle driving force control device according to any one of claims 1 to 10, further comprising means for estimating a weight gradient resistance.