JPH07172217A - Vehicular drive force controller - Google Patents

Abstract

PURPOSE:To obtain the most adequate drive force expected by a driver with driver's accelerator operation and also attempt the compatibility of an operation performance with a power ability when the controller is applied to a vehicle provided with a step type transmission, in a vehicular drive force controller for controlling the output of a power train system by means of a synthetic control, etc., of an engine and an automatic transmission. CONSTITUTION:In the first constitution, is provided a drive force control means (f) for controlling so that a target drive force to be outputted can be obtained in a power train system by a request effective drive force and a running resistance component calculated by using a realizable maximum/minimum drive force and an accelerator operation amount in relation to a car speed. The second constitution is rendered such a means that may make calculation of requested effective drive force defined by a requested effective drive force calculation means (c) is achieved in such a manner that the interconnection of a drive force to a car speed within the maximum drive force is calculated by a smoothed drive force and the minimum drive force when an accelerator operation amount is less than a prescribed value, and it is calculated by the maximum drive force a the minimum drive force when the accelerator operation amount is the prescribed value or more.

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 system for controlling the output of a powertrain system by comprehensive control of an engine and an automatic transmission.

[0002]

2. Description of the Related Art Conventionally, as an engine control device of a driving force control device for a vehicle, for example, Japanese Patent Laid-Open No. 1-29093 is known.
There is a device described in Japanese Patent Laid-Open No. 4-238748, and a control device for an automatic transmission is described in Japanese Patent Laid-Open No. 1-238748.

[0003]

However, in the above-mentioned conventional engine control device, the throttle of the engine is connected to the accelerator pedal by a wire, and basically all controls correspond to the accelerator operation of the driver. Since it is performed according to the intake air amount and the engine speed that appear as a result of the behavior of the throttle,
The control intended for the actual engine output is hardly performed.

Further, the control device for the automatic transmission controls the shift and lockup according to a preset shift schedule (including lockup). That is, the control intended for the output shaft torque is not performed here either.

However, it is considered that what the driver actually expects from the accelerator operation is the acceleration or driving force (output shaft torque) corresponding thereto.

[0006] In response to the expectations of such drivers, the current system has the above-mentioned configuration, and therefore cannot meet the expectations.

Also proposed is a combination of an engine and a continuously variable transmission which sets the operating state of the engine and the operating state of the continuously variable transmission according to the accelerator operation amount and the vehicle speed, but as a total. The concept of setting the target driving force is weak, and it is not possible to deal with the maximum driving force that can be realized such as a stepped transmission that has a discontinuity point.

The present invention has been made in view of the above problems. A first object of the present invention is to provide a driving force of a vehicle for controlling output of a power train system by comprehensive control of an engine and an automatic transmission. The purpose of the control device is to obtain the optimum driving force that the driver expects from the accelerator operation.

A second object is to achieve both the driving performance and the power performance when applied to a vehicle having a stepped transmission.

[0010]

In order to achieve the above first object, the vehicle driving force control apparatus of the first invention is an accelerator for detecting an accelerator operation amount of a driver as shown in the claim correspondence diagram of FIG. The operation amount detecting means a, the vehicle speed detecting means b for detecting the vehicle speed, the maximum driving force that can be realized with respect to the vehicle speed, the minimum driving force that can be realized with respect to the vehicle speed, and the accelerator operation amount are used to obtain the required effective driving force. A required effective driving force calculation means c for calculating, a traveling resistance component calculation means d for calculating a traveling resistance component of the vehicle according to the vehicle speed, and a target drive to be output by the power train system based on the required effective driving force and the traveling resistance component. A target driving force setting means e for setting a force and a driving force control means f for controlling the output of the power train system so as to obtain the set target driving force are provided.

In order to achieve the second object, the vehicle driving force control device of the second invention is the vehicle driving force control device according to claim 1, wherein the required effective driving force calculation means c.
Is the maximum drive force that can be achieved with respect to the vehicle speed, the drive force that smooths the connection of the drive force with respect to the vehicle speed within the maximum drive force, and the minimum drive force that can be achieved with respect to the vehicle speed. When the operation amount is less than a predetermined value, the required effective driving force is calculated by the smoothing driving force and the minimum driving force, and when the accelerator operation amount is more than the predetermined value, the required effective driving force is calculated by the maximum driving force and the minimum driving force. Is characterized by.

[0012]

The operation of the first invention will be described.

When the vehicle is traveling, the required effective driving force calculating means c has a maximum driving force that can be realized with respect to the vehicle speed from the vehicle speed detecting means b and a minimum driving force that can be realized with respect to the vehicle speed from the vehicle speed detecting means b. The required effective driving force is calculated using the accelerator operation amount from the accelerator operation amount detecting means a. Further, the traveling resistance component calculating means d calculates the traveling resistance component of the vehicle according to the vehicle speed. Then, the target driving force setting means e sets the target driving force to be output by the power train system based on the required effective driving force and the running resistance, and the driving force control means f obtains the set target driving force. The output of the power train system is controlled.

Therefore, the engine and the automatic transmission are not independently controlled, but the target driving force is set by reflecting the driver's intention of acceleration or driving force by the accelerator operation amount, and the set target driving force is set. As described above, the output of the powertrain system by the engine and the automatic transmission etc. is comprehensively controlled, and the driving with the optimum driving force that the driver expects by the accelerator operation can be obtained.

The operation of the second invention will be described.

In calculating the required effective driving force, the required effective driving force calculating means c drives the smoothed connection between the maximum driving force that can be realized with respect to the vehicle speed and the driving force with respect to the vehicle speed within the maximum driving force. Force and the minimum driving force that can be realized with respect to the vehicle speed are set, and if the accelerator operation amount is less than the predetermined value, the required effective driving force is calculated by the smoothing driving force and the minimum driving force, and if the accelerator operation amount is the predetermined value or more. The required effective driving force is calculated from the maximum driving force and the minimum driving force.

Therefore, when the accelerator operation amount is small, the setting of the target driving force is set to give priority to the continuity of the driving force, and when the accelerator operation amount is large, to be set to give priority to the absolute driving force. When applied to a vehicle having a stepped transmission in which gear positions appear stepwise, both driving performance and power performance are compatible.

[0018]

Embodiments of the present invention will be described below with reference to the drawings.

First, the structure will be described.

FIG. 2 is a general control system diagram of an engine-automatic transmission to which the driving force control device for a vehicle according to the embodiment of the present invention is applied.

In FIG. 2, 1 is an accelerator sensor for detecting an accelerator operation amount of a driver, 3 is an air flow meter for detecting the amount of air taken into the engine 2, and 1 is an air flow meter.
1 is a rotation sensor for detecting the rotation speed of the engine 2,
6 is a vehicle speed sensor for detecting the output shaft rotation speed of the automatic transmission 5 to calculate the traveling speed of the vehicle, 7 and 8 are shift solenoids for realizing gear shifting, and 9 is a lockup clutch in the converter of the automatic transmission 5. A lock-up solenoid 10 for controlling the operation of the control unit 10 is a control unit for inputting signals from the above-mentioned sensors and performing processing described later to output a control command to the throttle actuator 4, shift solenoids 7 and 8, and lock-up solenoid 9. is there.

Functionally dividing the contents of the arithmetic processing performed by the control unit 10, there are a target driving force setting section 10a, an optimum combination selecting section 10b, an engine control section 10c, and an automatic transmission control section 10d. .

Next, the operation will be described.

[Target Driving Force Setting] FIG. 3 is a flowchart showing the flow of the target driving force setting processing operation performed by the target driving force setting unit 10a of the control unit 10. Each step will be described below.

(1) In step 20, the accelerator operation amount accel_sen of the driver is read (corresponding to the accelerator operation amount detecting means a).

This accelerator operation amount accel_sen is, for example, as shown in the accelerator operation amount calculation flow chart of FIG. 4, a signal accel_ad from the accelerator sensor 1 which is A / D converted in a cycle of 5 ms, and is set to a set voltage when fully closed. ACCEL_MIN
And the set voltage ACCEL_MAX at the previous time are used for calculation. That is, when accel_ad ≦ ACCEL_MIN, accel_sen = 0 is set (steps 20a and 20b), and accel_ad ≧ AC.
When CEL_MAX, accel_sen is set to 80 degrees (steps 20c and 20d), and ACCEL_MIN <accel_ad <ACCEL_.
At the time of MAX, the accelerator operation amount accel_sen is calculated using the following formula (step 20e).

Accel_sen = 80 * (accel_ad-ACCEL_MI
N) / (ACCEL_MAX-ACCEL_MIN) (2) In step 21, the traveling speed vsp_sen of the vehicle is read (corresponding to the vehicle speed detection means b).

The traveling speed (vehicle speed) vsp_sen of this vehicle is
For example, as shown in the vehicle speed calculation flowchart of FIG. 5, the pulse signal from the vehicle speed sensor 6 provided on the output shaft of the automatic transmission 5 is counted for a predetermined time (100 ms), and the output shaft speed out_rev is calculated by the following formula. Is calculated (step 2
1a, 21b) and the output shaft speed out_rev is calculated by the following formula (step 21c). Step 21d is a step of clearing the counter value C.

Out_rev = k.multidot.C vsp_sen = V1000 * out_rev V1000 * coefficient determined by vehicle specifications (3) In step 22, the driver's required effective driving force n_to corresponding to the accelerator operation amount accel_sen and the vehicle speed vsp_sen.
(Direct driving force corresponding to acceleration / deceleration of the vehicle) is calculated (corresponding to the required effective driving force calculation means c).

This required effective driving force n_to is, for example, as shown in FIG.
As shown in Fig. 7, the gain is calculated corresponding to the accelerator operation amount accel_sen, and as shown in Fig. 7, the maximum driving force MAX_TO that can be realized with respect to the vehicle speed vsp_sen and the minimum driving force that can be realized with respect to the vehicle speed vsp_sen. MIN_TO is calculated, and these are calculated by the following formula.

N_to = gain * (MAX_TO-MIN_TO) + MIN_TO Or, in order to achieve both power performance and smooth running,
As shown in FIG. 8, the gain is calculated corresponding to the accelerator operation amount accel_sen, and as shown in FIG. 9, the maximum driving force MAX_TO that can be realized with respect to the vehicle speed vsp_sen and the minimum achievable with respect to the vehicle speed vsp_sen. Driving force MIN_TO and maximum driving force MAX_
The driving force SM_MAX_TO is calculated by smoothing the connection of the driving force to the vehicle speed vsp_sen in the TO, and the accelerator operation amount is calculated.
When accel_sen is less than the predetermined value SM_ACCEL, the required effective driving force n_to is calculated by the smoothing driving force SM_MAX_TO and the minimum driving force MIN_TO by the following formula, and the accelerator operation amount acce
When l_sen is greater than or equal to the specified value SM_ACCEL, the maximum driving force MAX_
The required effective driving force n_to is calculated by the following formula from the TO and the minimum driving force MIN_TO.

Accel_sen <SM_ACCEL n_to = gain * (SM_MAX_TO-MIN_TO) + MIN_TO accel_sen ≧ SM_ACCEL n_to = gain * (MAX_TO-MIN_TO) + MIN_TO (4) In step 23, the vehicle running resistance rl_to (for example, 0%) by the vehicle speed vsp_sen. The gradient) is calculated (corresponding to the running resistance component calculating means d).

Here, the running resistance component rl_to is preset as table data corresponding to the vehicle speed, as shown in FIG. 10, and is calculated using this table data.

(5) In step 24, the target driving force t_to to be output by the power train system is determined by the sum of the required effective driving force n_to obtained in step 22 and the running resistance component rl_to obtained in step 23. (Target driving force setting means e
Equivalent to).

T_to = n_to + rl_to [Determination of control target of power train system] Here, a method of determining the control target of the engine 2 and the control target of the automatic transmission 5 will be described. It should be noted that the automatic transmission 5 will be described using a 4-speed shift. Basically, the combination of engine / automatic transmission states that achieves the target driving force t_to and that consumes the least amount of fuel is selected.
Set the control target for each automatic transmission.

FIG. 11 is a flow chart showing the flow of the control target determination processing operation of the power train system performed by the optimum combination selection section 10b of the control unit 10.
Each step will be described below.

(1) In step 30, the target driving force t_to and the output shaft rotational speed out_rev are read.

(2) In step 31, in the following loop process, a variable (best
_gear, best_lu, best_ne, best_te, best_fuel)
Is cleared.

(3) In step 32, the following loop processes (4) to (9) are performed for possible combinations of automatic transmissions (gear positions: 1st to 4th speed, converter / lockup).

(4) In step 33, the turbine speed Nt and the turbine torque Tt for satisfying the above conditions are calculated by the following equations. GEAR_RATIO is gear ratio data and GEAR_ETA is gear efficiency data.
It is data set in advance corresponding to gp.

Nt = out_rev * GEAR_RATIO Tt = t_to / (GEAR_RATIO * GEAR_ETA) (5) In step 34, the turbine speed Nt, the turbine torque Tt, and the engine speed Ne and the engine torque Te required by the torque converter characteristics are calculated. It is calculated.
The torque converter characteristics are set in advance as shown in FIGS. 12 (a) and 12 (b). In the case of the lockup condition, the turbine speed Nt and the turbine torque Tt are directly substituted into the engine speed Ne and the engine torque Te.

(6) In step 35, it is checked whether the engine speed Ne and the engine torque Te are within the controllable range of the engine (details will be described later).
Then, it is determined whether or not it is within the control range, and if it is out of the range, the process returns to step 32 and the calculation is performed with the combination of the next candidates. If it is within the range, the process proceeds to step 37.

(7) In step 37, the required fuel consumption fuel is calculated from the engine speed Ne, the engine torque Te and the fuel consumption data. The fuel consumption data is set in advance as shown in FIG.

(8) In step 38, it is determined whether or not best_gear = 0, and in step 39, the fuel consumption amount fuel
Is determined to be less than or equal to the fuel consumption amount best_fuel in the optimal combination, and in step 40, the above variable (best_g
ear, best_lu, best_ne, best_te, best_fuel) are updated.

If it is determined at step 38 that best_gear ≠ 0 and at step 39 that fuel ≦ best_fuel, the current combination is updated as the optimum one.

When it is judged at step 38 that best_gear = 0, this variable is updated because the current combination is the first controllable combination.

(9) If it is judged at step 38 that best_gear ≠ 0, and if it is judged at step 39 that fuel> best_fuel, the process returns to step 32 to perform the calculation with the next candidate.

When all the combinations have been calculated, the process proceeds from step 32 to step 41. In step 41, the optimum combination is set as the required value n _ ^** for the engine / automatic transmission.

N_te = best_te, n_ne = best_ne:
Required value to engine n_gear = best_gear, n_lu = best_lu: Required value to automatic transmission [Check of engine controllable range] FIG. 13 is a flowchart showing a flow of control range check processing operation performed at step 35. .

(1) In step 35a, the engine speed Ne and the engine torque Te calculated in step 34 are input.

(2) In steps 35b and 35c, it is checked whether the engine speed Ne is within the controllable range.

(3) In steps 35d and 35e, it is checked whether the engine torque Te is within the controllable range.

(4) If it is judged to be outside the controllable range in any of steps 35b to 35e, step 3
Go to 5g and return "NG". Also, step 35
If it is determined in all of steps b to 35e that the control is possible, the process proceeds to step 35f and "OK" is returned.

The data indicating the controllable torque range (TE_MIN, TE_MAX) is preset as data corresponding to the engine speed, as shown in FIG.

[Control of Automatic Transmission] Basically, the selection of the traveling gear position and the converter state is changed with respect to the conventional automatic transmission control device.

That is, in the past, it was determined by the throttle opening, the vehicle speed, and the preset schedule, but here, the required value (n_gear: gear) to the automatic transmission selected from the optimum combination described above is used. The automatic transmission control unit 10d of the control unit 10 performs shift control and lockup control according to the position, n_lu: converter / lockup).

A conventional automatic transmission control device is, for example, "Nissan Full Range E-AT Maintenance Manual".
(A261C10), pages I-24 to 60.

[Engine Control] Here, only the throttle opening is controlled. Control of fuel, ignition, etc. is similar to that of the conventional engine control device.

FIG. 15 is a flowchart showing the flow of the throttle opening control operation performed by the engine control section 10c of the control unit 10. Each step will be described below.

(1) In step 50, the required value (n_te: torque, n_ne: rotational speed) for the engine is read.

(2) At step 51, the target horsepower t_ps as the engine is calculated from the required engine speed n_ne and the required engine torque n_te by the following formula. Since the shift of the automatic transmission is actually delayed, the engine side will be controlled by the actual engine speed eng_rev.

T_ps = k * n_ne * n_te k: coefficient (3) At step 52, the current engine speed eng_rev
Is read. As the engine speed eng_rev, for example, as shown in FIG. 16, the termer value is read (step 52a) and the timer is reset (step 52).
b), according to the procedure of calculating the engine speed eng_rev from the timer value (step 52c),
The period of the pulse signal from the rotation sensor 11 is measured and calculated.

(4) In step 53, the target horsepower t_ps and
The target torque t_te of the engine is calculated from the current engine speed eng_rev.

T_te = k * t_ps / eng_rev k: coefficient (5) In step 54, the engine characteristic data (TV) is calculated based on the target torque t_te and the current engine speed eng_rev.
O_MAP) is used to calculate the throttle opening, and this value is used as the open control value t_tvo for throttle control.

Further, the engine characteristic data (QA_MA) is calculated from the target torque t_te and the current engine speed eng_rev.
P) is used to calculate the required intake air amount, and the target value t_qa of the intake air amount for feedback control of the throttle opening is set.

The engine characteristic data (TVO_MAP, QA_MA
As shown in FIG. 17, P) is preset in a form corresponding to the rotation speed and torque.

(6) At step 55, the present intake air amount
qa_sen is read.

As for the intake air amount qa_sen, as shown in FIG. 18, the A / D value qa_ad of the intake air amount signal from the air flow meter 3 which is A / D converted in the cycle of 5 ms is obtained (step 55a). The A / D value is converted and calculated according to the linearization characteristic shown in FIG.

(7) At step 56, the present intake air amount
From qa_sen and the target intake air amount t_qa, the correction amount d_tvo of the throttle opening is calculated by the following formula. The feedback control method is the same as general control.

D_tvo = kp * (t_qa-qa_sen) + ki * (t_
qa-qa_sen) (8) In step 57, the above-mentioned correction value d_tvo is added to the throttle open control value t_tvo obtained in (5) to obtain the final throttle opening command value, and the command voltage to the throttle actuator 4 is calculated. Converted to tvo_out.

Determination of the control target of the power train system,
The automatic transmission control and the engine control are performed by the driving force control means f.
Equivalent to.

Next, the effect will be described.

As described above, in the vehicle driving force control device of the embodiment, first, the target driving force t_to as a vehicle is set by the accelerator operation amount accel_sen of the driver and the vehicle speed vsp_sen, and this target is set. In order to achieve the efficiency efficiently, the throttle opening of the engine 2, the gear position of the automatic transmission 5, and the converter state are controlled, so that the driving force almost as expected by the driver can be obtained and the fuel consumption can be reduced. it can.

Although the embodiments have been described above with reference to the drawings, the specific configuration is not limited to the embodiments, and modifications and additions within the scope of the present invention are included in the present invention. Be done.

For example, in the embodiment, the example of application to the power train by the combination of the engine and the stepped transmission is shown, but the present invention is also applied to the vehicle equipped with the power train by the combination of the engine and the continuously variable transmission. You can

In the embodiment, when the running resistance is calculated, the example in which it is calculated by the vehicle speed is shown, but it may be calculated in consideration of the road surface gradient, the road surface friction coefficient and the like in addition to the vehicle speed.

[0077]

According to the present invention as set forth in claim 1, it is possible to realize the vehicle driving force control device for controlling the output of the power train system by the comprehensive control of the engine and the automatic transmission. Effective driving force calculation means for calculating the required effective driving force using the minimum driving force and accelerator operation amount that can be realized for various maximum driving forces and vehicle speeds, and traveling for calculating the running resistance of the vehicle according to the vehicle speeds Resistance component calculating means, target driving force setting means for setting a target driving force to be output in the power train system based on the required effective driving force and the running resistance component,
Since the device is provided with the driving force control means for controlling the output of the powertrain system so that the set target driving force is obtained, the effect that the driver can obtain the optimum driving force expected by the accelerator operation Is obtained.

According to the second aspect of the present invention, in the vehicle driving force control apparatus according to the first aspect, the required effective driving force calculating means is a maximum driving force that can be realized with respect to the vehicle speed,
The driving force that smoothes the connection of the driving force to the vehicle speed within the maximum driving force and the minimum driving force that can be realized to the vehicle speed are set, and if the accelerator operation amount is less than the predetermined value, the smoothing driving force and the minimum driving force are set. The required effective driving force is calculated according to the above formula, and the required effective driving force is calculated based on the maximum driving force and the minimum driving force when the accelerator operation amount is equal to or greater than a predetermined value. It is possible to obtain the effect that both power performance can be achieved.

[Brief description of drawings]

FIG. 1 is a claim correspondence diagram showing a vehicle driving force control apparatus of the present invention.

FIG. 2 is a general control system diagram of an engine-automatic transmission to which the driving force control device for a vehicle according to the embodiment of the present invention is applied.

FIG. 3 is a flowchart showing a flow of a target driving force setting process operation performed by a target driving force setting unit of the control unit of the embodiment apparatus.

FIG. 4 is a flowchart for calculating an accelerator operation amount in a target driving force setting process.

FIG. 5 is a vehicle speed calculation flowchart in a target driving force setting process.

FIG. 6 is a gain characteristic diagram with respect to an accelerator operation amount when calculating a required effective driving force.

FIG. 7 is a driving force characteristic diagram with respect to a vehicle speed when calculating the required effective driving force.

FIG. 8 is a gain characteristic diagram with respect to an accelerator operation amount when calculating a required effective driving force.

FIG. 9 is a driving force characteristic diagram with respect to a vehicle speed when calculating the required effective driving force.

FIG. 10 is a running resistance characteristic diagram with respect to vehicle speed.

FIG. 11 is a flowchart showing a flow of a request setting process operation for a power train system with respect to a target driving force in the embodiment apparatus.

FIG. 12 is a data map used in a power train system requirement setting process.

FIG. 13 is an engine controllable range check processing flowchart.

FIG. 14 is an example of a controllable range map of engine torque and engine speed.

FIG. 15 is a flowchart showing a flow of throttle opening control operation.

FIG. 16 is a flowchart of an engine speed measurement process.

FIG. 17 is a data map of required throttle opening and intake air amount.

FIG. 18 is an AD conversion processing flowchart of an intake air amount signal.

FIG. 19 is a linearization characteristic diagram for converting an intake air amount signal AD value into an intake air amount value.

[Explanation of symbols]

 a accelerator operation amount detecting means b vehicle speed detecting means c required effective driving force calculating means d running resistance component calculating means e target driving force setting means f driving force control means

Claims (2)

[Claims] 1. An accelerator operation amount detecting means for detecting an accelerator operation amount of a driver, a vehicle speed detecting means for detecting a vehicle speed, a maximum driving force achievable with respect to the vehicle speed and a minimum driving force achievable with respect to the vehicle speed. A required effective driving force calculating means for calculating a required effective driving force using the accelerator operation amount and a traveling resistance component for calculating a traveling resistance component of the vehicle according to a vehicle speed; and the required effective driving force and the traveling resistance component. A target drive force setting means for setting a target drive force to be output by the power train system, and a drive force control means for controlling the output of the power train system so that the set target drive force is obtained. A driving force control device for a vehicle characterized by the above. 2. The driving force control device for a vehicle according to claim 1, wherein the required effective driving force calculation means is a maximum driving force that can be realized with respect to a vehicle speed and a driving force with respect to the vehicle speed within the maximum driving force. Is set to a smoothed driving force and the minimum driving force that can be realized for the vehicle speed. If the accelerator operation amount is less than the specified value, the required effective driving force is calculated using the smoothing driving force and the minimum driving force, and the accelerator operation is performed. A driving force control device for a vehicle, which is means for calculating a required effective driving force based on a maximum driving force and a minimum driving force when the amount is a predetermined value or more.