JP3323971B2 - Vehicle running resistance detection device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an apparatus for detecting running resistance of a vehicle, and more particularly to a technique for accurately detecting the running resistance of a vehicle in accordance with a change in data of a vehicle.

[0002]

2. Description of the Related Art Hitherto, there has been proposed a system for determining a running resistance of a vehicle and controlling an internal combustion engine, a driving force transmission system, a brake and the like of the vehicle according to the running resistance. For example, in a road surface slope detecting device disclosed in Japanese Patent Application Laid-Open No. 3-90808, while a driving force F is calculated based on an output of a torque sensor, traveling such as acceleration resistance, rolling resistance, air resistance and the like is determined based on vehicle weight, vehicle speed, and the like. The resistance is obtained, and the gradient resistance (road surface gradient) during which the vehicle is traveling is calculated from the correlation between the driving force F and the traveling resistance.

[0003]

SUMMARY OF THE INVENTION Incidentally, Japanese Patent Application Laid-Open No.
In the road surface gradient detecting device disclosed in Japanese Patent Publication No. 90808,
The gradient is detected by assuming that the vehicle weight is constant and that the values of the rolling resistance and air resistance (flat road running resistance) according to the vehicle speed are also constant. Changes, and a change in rolling resistance also occurs due to tire replacement or the like.

For this reason, in the above-mentioned conventional apparatus, running resistance (gradient resistance) cannot be obtained stably and accurately.
As a result, there is a problem that the internal combustion engine, the driving force transmission system, the brake, and the like of the vehicle cannot be controlled with high accuracy according to the running resistance of the vehicle. The present invention has been made in view of the above problems, and can easily detect a change in vehicle specification data such as a flat road running resistance according to a vehicle weight or a vehicle speed. It is an object of the present invention to provide a running resistance detection device that can be used.

[0005]

Therefore, a vehicle running resistance detecting apparatus according to the present invention is configured as shown in FIG. In FIG. 1, the driving state detecting means detects the driving state of the vehicle, and the running resistance calculating means calculates the running resistance of the vehicle based on the detected driving state of the vehicle and the specification data of the vehicle.

The vehicle specification data updating means updates and sets the specification data of the vehicle used in the running resistance calculating means based on the average value of the running resistance calculated by the running resistance calculating means. Here, the driving state detecting means is configured to detect at least the vehicle speed, and the vehicle specification data updating means is configured to obtain an average value of the running resistance calculated by the running resistance calculating means for each vehicle speed. While
The running resistance calculating means includes at least a running resistance value corresponding to a vehicle speed as specification data, and the vehicle specification data updating means includes a driving resistance corresponding to the vehicle speed based on an average value of the running resistance obtained for each vehicle speed. The resistance value data may be configured to be updated for each vehicle speed.

Further, the vehicle specification data updating means calculates an average value of the running resistance calculated by the running resistance calculating means,
On the other hand, the traveling resistance calculation means includes at least data of the vehicle weight as the specification data while the vehicle specification data updating means includes the transient operation state and the transient operation state of the vehicle. The vehicle weight data may be updated based on the average value of the running resistance individually obtained in the steady driving state.

[0008]

According to this configuration, it is possible to average the values of the climb resistance and the downhill experienced in the running resistance, which are averaged during the climbing and descent. It can be considered that the value becomes substantially zero by averaging. Therefore, when the long-term average does not become zero, it is possible to estimate the error of the specification data used for calculating the slope resistance, and by taking the long-term average as described above, a running resistance component other than the slope resistance can be estimated. It can be extracted, and the error of the specification data used for calculating the running resistance component can be estimated.

When an error in the running resistance that changes in accordance with the vehicle speed represented by the flat road running resistance is determined, an average value of the running resistance is determined for each vehicle speed, thereby obtaining a different error for each vehicle speed. Therefore, it is possible to update the data of the running resistance corresponding to the vehicle speed to a correct value. Furthermore, if the vehicle is separated into a transient driving state and a steady driving state and the average value of the running resistance is obtained, the acceleration resistance included in one running resistance and not included in the other can be extracted. Thus, an error in the vehicle weight, which serves as a reference for calculating the acceleration resistance, can be obtained.

[0010]

Embodiments of the present invention will be described below. In FIG. 2 schematically showing a system configuration of an embodiment, an automatic transmission 2 is provided on an output side of an internal combustion engine 1 mounted on a vehicle (not shown). The automatic transmission 2 includes a hydraulic torque converter 3 interposed on the output side of the engine 1 and a gear type transmission 4 connected via the hydraulic torque converter 3.
And a hydraulic actuator 5 for connecting / disconnecting various transmission elements in the gear type transmission 4. The operating hydraulic pressure for the hydraulic actuator 5 is controlled via various electromagnetic valves, but here only the shift electromagnetic valves 6A and 6B for automatic shifting are shown. Reference numeral 7 denotes an output shaft of the automatic transmission 2.

Here, an oil pump 8 driven by an input shaft of the gear type transmission 4 is used to obtain a line pressure which is an operating oil pressure for the hydraulic torque converter 3 and the hydraulic actuator 5, and a pilot valve 9. , Solenoid valve 10, pressure modifier valve 11
And a pressure regulator valve 12.

The pilot valve 9 regulates the discharge pressure of the oil pump 8 to a pilot pressure acting on the electromagnetic valve 10. The electromagnetic valve 10 is duty-controlled as described below,
The pilot pressure is adjusted to a throttle pressure according to the operating conditions. The pressure modifier valve 11 adjusts the pilot pressure to a pressure modifier pressure according to the throttle pressure, and acts on the pressure regulator valve 12. The pressure regulator valve 12 adjusts the oil pump discharge pressure to a line pressure proportional to the pressure modifier pressure, and sends it to a hydraulic circuit such as the hydraulic torque converter 3 and the hydraulic actuator 5.

The control unit 13 receives signals from various sensors. As the various sensors, a potentiometer type throttle sensor 15 for detecting the opening TVO of the throttle valve 14 of the intake system of the engine 1 is provided. Further, a crank angle sensor 16 is provided on a crank shaft of the engine 1 or a shaft (cam shaft) that rotates in synchronization with the crank shaft. The signal from the crank angle sensor 16 is
For example, a pulse signal for each reference crank angle is used to calculate the engine speed Ne based on the cycle.

Further, a hot-wire type air flow meter 17 for detecting an intake air flow rate Q is provided in an intake system of the engine 1. From the intake air flow rate Q detected by the air flow meter 17 and the engine rotation speed Ne calculated based on the signal of the crank angle sensor 16, the basic fuel used as the basis for calculating the fuel injection amount by the electronically controlled fuel injection device is calculated. Injection amount Tp =
K × Q / Ne (K is a constant) is calculated.

Further, a vehicle speed sensor 18 for detecting the vehicle speed VSP by detecting the rotation speed No of the output shaft 7 of the automatic transmission 2 is provided. Further, a turbine rotation sensor 19 for detecting a turbine rotation speed Nt in the fluid torque converter 3 is provided. The control unit 13 integrally incorporates a unit for engine control (fuel injection and ignition timing control) and a unit for automatic transmission control, and allows the units to exchange signals.

The unit for automatic shift control mainly performs shift control and line pressure control. The automatic shift control is performed in accordance with the operating position of a select lever (not shown) operated by the driver. In particular, when the select lever is in the D range, the automatic shift control is performed according to the throttle valve opening TVO and the vehicle speed VSP.
The shift positions of the first to fourth speeds are automatically set, the combination of ON / OFF of the shift electromagnetic valves 6A and 6B is controlled, and the gear type transmission 4 is controlled to the shift position via the hydraulic actuator 5.

Here, in the combination of the automatic transmission 2 and the engine 1 as described above, the shift pattern, the engagement force of the lock-up clutch, and the like are controlled by the running resistance (particularly, the slope resistance) of the vehicle on which the engine 1 is mounted. It is desired to change according to. Accordingly, the control unit 13 calculates the gradient of the road surface (gradient resistance) as shown in the flowchart of FIG. 3, and changes the shift pattern and the like in the automatic transmission according to the road surface gradient.

The routine shown in the flow chart of FIG. 3 is executed by interruption every predetermined time. In this embodiment, the function as the running resistance calculation means is as shown in the flow chart of FIG. The control unit 13 is provided as software. In this embodiment, the vehicle speed sensor 18, the turbine rotation sensor
19. The throttle sensor 15 corresponds to the operating state detecting means.

In the flowchart of FIG. 3, in step 1 (S1 in the figure, the same applies hereinafter), the throttle valve opening TVO detected by the throttle sensor 15 is read. In step 2, the turbine rotation speed Nt detected by the turbine rotation sensor 19 is read.

In step 3, a reference is made to a map in which the turbine torque Tt is stored using the turbine rotation speed Nt and the throttle valve opening TVO as parameters, and the current throttle valve opening TVO and the turbine rotation speed Nt are referred to.
The turbine torque Tt corresponding to is obtained. Further, in step 4, the driving force F of the vehicle is calculated as F = Tt × i × if × k using the turbine torque Tt, the gear ratio i of the transmission, the final gear ratio if, and the conversion coefficient k.

The turbine torque Tt may be stored using the basic fuel injection amount Tp of the internal combustion engine 1 as a parameter instead of the throttle valve opening TVO. Also,
In step 5, the standard vehicle weight M stored in advance is stored.
By adding the correction value M _HOS obtained as described later in _BASE, obtaining the modified vehicle weight _{M (= M BA SE + M} HOS).

In step 6, reference is made to a map in which standard running resistance R _{L BASE} (a flat road running resistance consisting of rolling resistance and air resistance) is stored in advance corresponding to the vehicle speed VSP, and the standard running resistance corresponding to the current vehicle speed VSP is referred to. _{Find the} resistance R _{L BASE} .
In step 7, a correction value R _{L BASE} corresponding to the current vehicle speed VSP is referred to with reference to a map in which the correction value R _{L HOS} of the standard running resistance _{RL BASE} is learned for each vehicle speed, as described later.
_Ask for _{L HOS} .

Then, in step 8, step 6
The standard running resistance R _{L BASE} obtained in
_Is added to obtain the final standard running resistance _RL (= _RLBASE + _RLHOS ). In step 9, the vehicle acceleration α is calculated based on the amount of change in the vehicle speed VSP per unit time.

In step 10, the acceleration α
And acceleration resistance Mα (= M × α) based on the vehicle weight M
Is calculated. In step 11, based on the driving force F, the acceleration resistance Mα, the standard running resistance _RL , the gravitational acceleration g, and the vehicle weight M, the gradient Sin (= sin θ) is calculated according to the following equation.

Sin = sin θ = (F−Mα−R _L ) / (M × g) In the above equation, driving force F = acceleration resistance Mα + standard running resistance R
It is set based on _L + gradient resistance M × g × sin θ. The gradient Sin (= sin) obtained as described above
θ) is used as control information for changing the shift pattern in the automatic shift control and controlling the engagement force of the lock-up clutch.

Here, how the correction value R _{L HOS} is learned will be described with reference to the flowchart of FIG. In this embodiment, the function as the vehicle specification data updating means is provided by the control unit 13 as software as shown in the flowchart of FIG. In the flowchart of FIG. 5, first, at step 21, the average value of the driving force F and the gradient Sin calculated at steps 4 and 11 of the flowchart of FIG. Is stored for each vehicle speed.

The storage of the gradient Sin and the driving force F is performed by storing the gradient Sin and the driving force F calculated at predetermined time intervals according to the flowchart of FIG. 3 as shown in FIG. And the average values SinM _n , FM _n
Are sequentially stored in correspondence with the vehicle speed VSP at the time of the determination. Therefore, in the storage of the average values SinM _n and FM _n , a state in which the vehicle speed is substantially stable at a constant vehicle speed within the time frame (steady operation state) is required.

Here, for each vehicle speed VSP, a plurality (n) of areas for storing the average values SinM _n and FM _n in the time frame are provided, whereby the average value in one to several hours is obtained for each vehicle speed. It can be calculated later. When the gradient Sin and the driving force F are stored, in the next step 23, the data of the driving force F stored (corresponding to the same vehicle speed VSP) (the average value in 10 to 30 minutes).
And a value obtained by dividing the difference between the integrated value of the gradient Sin and the integrated value of the gradient Sin stored as a pair with the data of the driving force F, ie, the average value of the driving force F in several hours. From the deviation of the gradient resistance Sin from the average value, the vehicle speed VSP is determined in advance.
_Is subtracted from the standard running resistance _{RL BASE} stored in accordance with the equation (1) to obtain a correction value R of the standard resistance _{RL at} the vehicle speed VSP.
_Set as _{L HOSN} .

[0029]

(Equation 1)

The average value Sin for the same vehicle speed VSP
M_n, FM_nWhen the number of stored data of
Is a correction value R corresponding to the vehicle speed VSP._{L HOSN}The operation of
It is preferable not to do this. Drive torque F
The relationship with the total running resistance is that the total running resistance is the acceleration resistance Mα, the slope
Distribution resistance Sin (= M × g × sin θ), standard running resistance R_L
(Flat road running resistance): F = Mα + R_L+ M × g × sin θ, but in the above embodiment, the driving force F and the gradient Si
The average value of n is stored for each vehicle speed VSP,
Since the anti-Mα can be regarded as zero, the correction value R _{L HOSN}
In the above calculation, the above equation is F = R_L+ M × g × sin θ
Can be

If the averaging time is set to be sufficiently long, climbing and descending are experienced on average, and it is assumed that the average value of the gradient Sin becomes zero. That is, when the long-term average of the gradient Sin is zero, F = _RL . On the other hand, if there is an error in the standard running resistance _RL calculated in the flowchart of FIG. It will be shown as the deviation of the value of the long-term average from zero.

Accordingly, the long-term average driving force F is
Map of the standard running resistance from the value obtained by subtracting the slope Sin
Data R_{L BASE}By subtracting the map data from the true value
Correction value R for correcting to_{L HOSN}Will be obtained
You. In step 23, the correction value R_{L HOSN}Ask and step
24, the correction value R_{L HO SN}Is actually the standard running resistance R
_{L BASE}R used for correction of_{L HOS}To the conversion table
And in the next step 25, the conversion
Correction value R_{L HOS}Based on the vehicle speed VSP
Correction value R_{L HOS}Of the vehicle speed VSP in the map in which
Rewrite the corresponding data. Here, the vehicle speed VSP
Correction value R according to _{L HOS}(Running resistance value)
Corresponds to the specification data.

The correction value R rewritten in step 25
The map of _{L HOS} is referred to in step 7 of the flowchart of FIG. 3 to correct and set the standard running resistance _RL used for obtaining the gradient Sin as a true value, thereby improving the calculation accuracy of the gradient Sin. Can be done. That is,
If the slope Sin is averaged over a long period of time, the value should be substantially zero. If not, the standard running resistance (flat road running resistance) R used when obtaining the slope Sin is used.
_Since there is an error in _L , it can be estimated that an error has occurred in the calculation result of the gradient Sin. Therefore, the standard traveling resistance _RL is corrected based on the error so that the gradient Sin becomes zero when long-term averaging is performed. To correct.

Therefore, if the rolling resistance changes due to tire replacement or the like and the initially set standard running resistance _RL does not match, such a mismatch appears as not becoming zero even if the long-term average of the slope Sin is obtained. Thus, the change in the standard running resistance _RL due to the tire replacement is corrected. Next, the setting of the correction value M _HOS used for correcting the vehicle weight M in step 5 of the flowchart of FIG. 3 will be described with reference to the flowchart of FIG.

In the flowchart of FIG. 6, first, at step 31, it is determined whether or not the vehicle is in an accelerating operation state. When the vehicle is not in the accelerating operation state, the routine proceeds to step 32, where the driving force F, the standard running resistance _RL , and the gradient Sin calculated in the flowchart of FIG.
As described above, an averaging process is performed in a predetermined time frame so that an average of one to several hours is obtained, and stored in chronological order.

On the other hand, when the vehicle is in the accelerated driving state, the routine proceeds to step 33, where the acceleration α calculated in step 9 of the flowchart of FIG. 3 is averaged in addition to the driving force F, the standard running resistance R _L , and the gradient Sin. And store it.
Here, the correlation between the driving force F during acceleration and the running resistance is expressed as F ₁ =
Assuming that R _L1 + M × g × sin θ and the correlation between the driving force F and the running resistance during non-acceleration is F ₂ = R _L2 + Mα + M × g × sin θ, the above equation can be obtained by taking the average over a sufficiently long time. The slope Sin becomes zero.

Therefore, in the next step 34, the long-term average of Sin is regarded as zero (or confirmed to be zero),
Assuming that F ₁ = R _L1 and F ₂ = R _L2 + Mα, the equation for deriving the true weight m is m = ｛(R _L1 −R _L2 ) − (F ₁ −
F ₂ )｝ / α. Then, the weight m is calculated by substituting the average values of the driving amounts F ₁ and F ₂ , the standard running resistances R _L1 and R _L2, and the acceleration α over several hours into the equation for deriving the weight m.

Then, in the next step 35, the aforementioned step
Weight m and standard weight M calculated in step 34 _BASEAnd the deviation ΔM from
In step 36, the deviation ΔM is calculated by a predetermined conversion text.
According to the standard weight M_BASETo correct
Correction value M_HOSConvert to In step 37, the step
Correction value M obtained in step 36_HOSIs actually the standard weight M_BASEof
Update and set as data used for correction.

As described above, by taking the average of the running resistance over a relatively long period of time to take advantage of the fact that the gradient resistance can be ignored, the weight M as the vehicle specification data is set to a true value. If the correction can be made, for example, when the actual vehicle weight changes due to a change in the number of occupants or the loading of luggage, the accuracy of the acceleration resistance Mα calculated using the vehicle weight is increased, and the slope Sin is reduced. It is possible to improve the estimation accuracy, and it is possible to perform optimal control (shift pattern control, lock-up control) on the gradient Sin at that time.

[0040]

As described above, according to the present invention, the running resistance is determined as a condition that the gradient resistance becomes zero by taking a relatively long-term average, so that the error of the gradient resistance or the gradient resistance is determined. There is an effect that an error of a running resistance component other than the resistance can be detected, and the specification data used for calculating the running resistance can be corrected to a true value.

In particular, if the long-term average value is obtained according to the vehicle speed, it is possible to detect an error in the running resistance (flat road running resistance) determined according to the vehicle speed for each vehicle speed. It becomes possible to cope with a change in the flat road running resistance due to the replacement. In addition, by taking the average of the running resistance separately for the transient and the steady state, it is possible to extract the acceleration resistance component while eliminating the influence of the gradient resistance by the long-term average. There is an effect that the used vehicle weight can be updated to a true value.

[Brief description of the drawings]

FIG. 1 is a block diagram showing a basic configuration of the present invention.

FIG. 2 is a system schematic diagram showing one embodiment of the present invention.

FIG. 3 is a flowchart showing how a gradient is detected.

FIG. 4 is a diagram showing a storage state of driving force and running resistance.

FIG. 5 is a flowchart showing a setting of a correction value of a standard running resistance.

FIG. 6 is a flowchart showing the setting of a correction value for vehicle weight.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Automatic transmission 3 Fluid torque converter 4 Gear type transmission 5 Hydraulic actuator 7 Output shaft 13 Control unit 14 Throttle valve 15 Throttle sensor 16 Crank angle sensor 17 Air flow meter 18 Vehicle speed sensor 19 Turbine rotation sensor

Claims (3)

(57) [Claims] 1. A driving state detecting means for detecting a driving state of a vehicle, and a running resistance for calculating a running resistance of the vehicle based on the driving state of the vehicle detected by the driving state detecting means and specification data of the vehicle. Calculation means; and vehicle specification data updating means for updating and setting the specification data used by the running resistance calculation means based on the average value of the running resistance calculated by the running resistance calculation means. A running resistance detecting device for a vehicle. 2. The driving state detecting means is configured to detect at least a vehicle speed, and the vehicle specification data updating means obtains an average value of the running resistance calculated by the running resistance calculating means for each vehicle speed. On the other hand, the running resistance calculation means includes at least the running resistance value corresponding to the vehicle speed as the specification data, and the vehicle specification data updating means determines the running resistance based on the average value of the running resistance obtained for each vehicle speed. The running resistance detecting device for a vehicle according to claim 1, wherein the data of the running resistance value corresponding to the vehicle speed is updated for each vehicle speed. 3. The vehicle resistance data updating means individually obtains an average value of the running resistance calculated by the running resistance calculating means in a transient operation state and a steady operation state of the vehicle, while calculating the running resistance. The means includes at least data of the vehicle weight as the specification data, and the vehicle specification data updating means includes:
The running resistance detection device for a vehicle according to claim 1, wherein the data of the vehicle weight is updated based on an average value of the running resistance individually obtained in a transient operation state and a steady operation state of the vehicle.