JP2002256918A - Vehicular driving control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicular driving control device for improving fuel consumption and exhaust performance by moderating an output change in an engine by operating an assist of a motor generator at transition time. SOLUTION: This vehicular driving control device sets a torque command value TEO to the engine 1 to a value of subtracting the performance upper limit Tmx of the motor generator 2 from required driving force (target torque TO) or a large value among engine driving force command values of restricting a variation TO-TEO to a prescribed ΔTex or less, and sets a torque command value TMO to the MG 1 to a value of subtrating the torque command value TEO to the engine from the required driving force (the target torque TO).

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a drive control device for a vehicle such as an automobile, and more particularly to a drive control device for a hybrid vehicle having an internal combustion engine and an electric motor as prime movers.

[0002]

2. Description of the Related Art As a prime mover (drive power source), a hybrid vehicle having an internal combustion engine and an electric motor has been proposed. In a hybrid vehicle, Japanese Patent Laid-Open No. 2000-2
As disclosed in Japanese Patent No. 13386, an operation system is adopted in which an electric motor having a good response is preferentially operated, and a shortfall with respect to a required output is supplemented by an output of the internal combustion engine.

[0003]

In the case of an electric motor having a small output, if the electric motor is used even during steady running, there is only a small amount of adjustment of the driving force by the electric motor, and changes in the driving force such as overtaking acceleration and climbing a slope are detected by the internal combustion engine. The institution will respond.

However, in order to enrich the fuel mixture ratio when the output of the internal combustion engine suddenly increases, it is necessary to compensate for all required driving force changes during transient operation with the output of the internal combustion engine.
Exhaust gas and fuel economy performance will be impaired.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems. It is an object of the present invention to effectively use the assist of an electric motor during a transient operation and moderate the output change of an internal combustion engine during a transient operation. Accordingly, it is an object of the present invention to provide a drive control device for a hybrid vehicle that improves fuel efficiency and exhaust performance of an internal combustion engine.

[0006]

In order to achieve the above object, a drive control apparatus for a vehicle according to the present invention comprises: an internal combustion engine; a rotary electric machine which also serves as an electric motor and generates electric power by using the internal combustion engine as a power source; In a drive control device for a vehicle, comprising a secondary battery that stores power generated by a rotating electric machine and supplies power to the rotating electric machine, a driving force is applied to the internal combustion engine and the rotating electric machine in accordance with an accelerator operation amount. A command value is output, and the command value to the internal combustion engine is a value obtained by subtracting the performance upper limit of the electric motor from the required driving force, or a difference between the required driving force and the current internal combustion engine command value is limited to a predetermined value or less. The command value to the rotary electric machine is a value obtained by subtracting the command value to the internal combustion engine from the required driving force, the value being the larger value of the value added to the current internal combustion engine command value.

According to the drive control apparatus for a vehicle according to the present invention, if the required driving force changes (increases) during the transient operation, it is covered by an increase in the output of the rotary electric machine, and the shortage is borne by the internal combustion engine. As a result, the output change of the internal combustion engine is reduced.

[0008] The command value to the internal combustion engine can be at least one of the amount of air supplied to the internal combustion engine or the fuel injection amount. Depending on the machine, it can be at least one of a current or a voltage supplied to the rotating electric machine.

[0009]

Embodiments of the present invention will be described below in detail with reference to the accompanying drawings. FIG. 1 shows a main configuration of a hybrid vehicle incorporating a vehicle drive control device according to the present invention. The hybrid vehicle has an internal combustion engine (engine) 1 and a motor generator (hereinafter, referred to as MG) 2 which is a rotating electric machine, and uses these as power sources to drive wheels 5 via a clutch 3 and a transmission 4. To communicate.

A hybrid control unit (HCU) 6, which is a control unit for the vehicle, starts and stops the hybrid vehicle system in response to a signal from a key switch 7, and responds to operation signals of an accelerator pedal 8 and a brake pedal 9 to control the operation of a wheel 5.
Control device (ECU) 10 for engine 1 and inverter 1 for controlling MG 2 so that necessary torque is applied to engine 1.
1 and the clutch 3.

The MG2 uses a battery 12 as a secondary battery as a power source, and converts the electric energy of the battery 12 into AC by an inverter 11 and gives the AC to MG2.
The MG 2 generates a driving force, starts the engine 1 connected via the belt 13, and also drives the wheels 5 via the clutch 3.

The battery 12 is different from a 12V battery which is a power supply of the HCU 6 or the like.
This is a 2V battery. The MG 2 is rotated by the kinetic energy of the wheels 5 or the driving force of the engine 1 to generate power, and is converted to direct current by the inverter 11 for charging.

The ECU 10 that performs engine control sends a target opening degree of the throttle valve 15, which is obtained from an engine speed obtained from a signal from the crank angle sensor 14 and a torque command value from the HCU 6, to a throttle opening control device 16. And control the air flow. Further, the ECU 10 controls the fuel injection time of the fuel injection device 19 based on the engine cooling water temperature detected by the water temperature sensor 17 and the detection signal of the oxygen concentration sensor 18 on the exhaust side.

A mixture of fuel and air is supplied from an intake port 21 opened and closed by an intake valve 20 to a combustion chamber 22 in a cylinder.
And is ignited by the ignition device 23. The piston 24 is moved by the explosion energy of the air-fuel mixture,
And MG2. The combustion gas is discharged out of the combustion chamber 22 from an exhaust port 26 opened and closed by an exhaust valve 25, purified by a catalytic converter 27, and then discharged to the atmosphere.

The system operation mode by the HCU 6 is 3
There are types. (Engine Start Mode) The first is an engine start mode. The maximum torque command value is given to the inverter 11, and the engine 1 is cranked by the MG2.
When the engine speed reaches 900 r / m, the fuel injection prohibition command value for the ECU 10 is released, and the engine 1 is started.

(Idle Stop Mode) The second is an idle stop mode. When the brake pedal 9 is depressed while the vehicle is stopped and the accelerator pedal 8 is released and there is no need to apply driving force to the wheels 5, the engine 1 is stopped and no fuel is consumed. (Running / Power Generation Mode) The case where none of the above two modes is applicable is the third mode. When the brake pedal 8 is released even in the running state or the stopped state as the running / power generation mode, the engine 1 The vehicle runs or generates power using the power as a power source.

The operation of the hybrid vehicle will be described with reference to a flowchart shown in FIG. 2 in which a control process embodied by executing software incorporated in the HCU 6 for giving command values to the ECU 10 and the inverter 11 is described.

This process is executed every 10 ms. First,
Operation signals of the key switch 7, the accelerator pedal 8, and the brake pedal 9 are input (step 101). Next, data such as a torque command value, a fuel injection prohibition command value, and a pumping loss control type are transmitted to the ECU 10 and the inverter 11, and the rotation speed of the MG 2 is received from the inverter 11 and the engine rotation speed is received from the ECU 10. (Step 102).

Next, according to the operation signals of the key switch 7 and the accelerator pedal 8 and the engine speed, the above-mentioned 3
One operation mode is selected from the two system operation modes (step 103). In the case of the engine start mode (Yes at Step 104), the processing of the engine start mode is executed (Step 105). In the case of the idle stop mode (Yes at Step 106), the process of the idle stop mode is executed (Step 107).

If neither of them is satisfied (step 106
No), as the running / power generation mode, a target torque TO corresponding to the required driving force is determined from the opening degree of the accelerator pedal 8 (accelerator operation amount) and the engine speed (step 1).
08). Next, a torque command value (target drive torque) TMO of MG2 and a torque command value (target drive torque) TEO of engine 1 are calculated (step 109).

The calculation of the torque command value is performed by a target driving force distribution process embodied by executing software incorporated in the HCU 6. The target driving force distribution processing will be described with reference to the flowchart of FIG. First, the target torque TO and the maximum torque of MG2 (M
A difference between the upper limit of G2 (performance upper limit) Tmx, that is, the minimum required torque Te1 = TO−Tmx required for the engine 1 is calculated (step 201).

Next, a difference TO-TEO between the target torque TO and the current engine torque command value TEO is obtained, and it is determined whether or not this difference is larger than a predetermined value ΔTex (step 202). TO-TEO is a predetermined value Δ
If it is larger than Tex (Yes at step 202), the variation of the engine torque Te2 is limited to a predetermined value ΔTex (step 203). This is Te2 = ΔTex + T
Means EO. On the other hand, TO-TEO is a predetermined value Δ
If it is not larger than Tex (No at step 202), the engine torque Te2 is directly used as the target torque TO.
(Step 204).

Next, the minimum required torque Te1 required for the engine 1 is compared with the engine torque Te2 (step 205). If Te1> Te2 (step 20)
(5 affirmative), the minimum required torque Te1 is set as the target torque TO. In other words, when the amount of change in the engine torque Te2 is limited to the predetermined value ΔTex or less, if the torque becomes insufficient, the minimum required torque Te1 required for the engine 1 is set as a new engine torque command value TEO (step 20).
6).

On the other hand, if Te1> Te2 is not true (No at step 205), in other words, if the variation in the engine torque Te2 is limited to a predetermined value ΔTex or less, the engine torque will not be insufficient. Te2 is set as a new engine torque command value TEO (step 2).
07).

Then, the difference TO-TEO between the target torque TO and the new engine torque command value TEO is set as the MG torque command value TMO (step 208). Engine 1
Is based on the command value given from the HCU 6
Is controlled by the command value issued by. Hereinafter, control processing embodied by execution of software incorporated in the ECU 10 will be described with reference to a flowchart shown in FIG.

This process is executed every 10 ms. First,
The signals from the water temperature sensor 17 and the oxygen concentration sensor 18 provided in the exhaust pipe are input (step 301). Next, HCU
The data such as the engine torque command value TEO received by the data communication with the controller 6 is taken in, and transmission data such as the engine speed is set (step 302).

Next, the target opening of the throttle valve 15 for controlling the air flow rate is determined from the detected engine speed and the given engine torque command value TEO (step 30).
3) Output to the throttle control device 16. As a result, the amount of air supplied to the engine 1 is measured and controlled.

Next, the target injection pulse width of fuel (time)
Is calculated (step 304). However, when the fuel injection prohibition command value is issued, the target injection pulse width is set to zero.
Control of the fuel injection device 20 according to the target injection pulse width
Performed in another interrupt process. Thereby, the fuel injection amount supplied to the engine 1 is measured and controlled. Next, the intake valve 20
And the opening / closing timing of the exhaust valve 25 is calculated (step 20).
5).

Next, an inverter 11 for controlling MG2
Will be described. Inverter 11 performs data communication with HCU 6 in the same manner as ECU 10, and applies an AC current necessary for obtaining torque from battery 12 to MG2 in accordance with received MG torque command value TMO. Note that MG2
Is a DC machine, apply a voltage to obtain the required torque.

FIG. 5 shows a change in the torque command value with respect to the operation amount of the accelerator pedal 8 (accelerator opening). The torque command value TO of the engine + MG is determined according to the operation amount of the accelerator pedal 8, and the torque command value TMO to the MG2 is output at the time of transition, so that the torque command value TE to the engine is obtained.
O changes slowly.

In the above-described target driving force distribution processing, when the operation amount of the accelerator pedal 8 (accelerator opening) is stable and the target torque TO is substantially constant, step 202 in FIG.
By the processing of step 204, the engine torque command value T
EO acts so as to match the target torque TO, and the MG torque command value TMO obtained in step 208 becomes zero.

When the accelerator pedal 8 is depressed and the target torque TO increases, the amount of increase in torque is determined in step 201.
Step 2 covers the motor with the torque of MG2.
In the process 06, the engine 1 bears the insufficient torque.

By these processes, the required torque of the engine 1 can be moderately changed without impairing the traveling performance, and the effect of enriching the fuel mixture ratio and preventing the deterioration of the exhaust gas and fuel efficiency due to it can be prevented. is there.

As described above, one embodiment of the present invention has been described in detail. However, the present invention is not limited to the above-described embodiment, and may be designed without departing from the spirit of the present invention described in the appended claims. Can be variously changed.

[0035]

According to the vehicle drive control apparatus of the present invention, the engine is used as a driving force source during steady running, and the motor generator (MG) is used to cover the increase in required torque during transition. This has the effect of easing the required torque change to the engine without damaging the engine and preventing deterioration of exhaust gas and fuel efficiency.

[Brief description of the drawings]

FIG. 1 is a diagram showing a main configuration of a hybrid vehicle incorporating a vehicle control device as one embodiment of the present invention.

FIG. 2 is a flowchart of hybrid control in the control device for a hybrid vehicle as an embodiment of the present invention.

FIG. 3 is a flowchart of a target driving force distribution process in the hybrid vehicle control device according to the embodiment of the present invention;

FIG. 4 is a flowchart of engine control in the hybrid vehicle engine control device as an embodiment of the present invention.

FIG. 5 is a time chart showing a change in a torque command value with respect to an accelerator opening in a hybrid vehicle engine control device as an embodiment of the present invention.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 1 Internal combustion engine 2 Motor generator (MG) 5 Wheel 6 Hybrid control device (HCU) 7 Key switch 8 Accelerator pedal 9 Brake pedal 10 Engine control device (ECU) 11 Inverter 12 Battery 16 Throttle opening control device 20 Fuel injection device 20 Intake valve 22 Combustion chamber 23 Ignition device 24 Piston 25 Exhaust valve

 ──────────────────────────────────────────────────続 き Continued on the front page F term (reference) 3G093 AA07 AA16 BA19 BA20 BA22 CB06 DA05 DA06 DA07 DA11 DB01 DB15 EA05 EA09 EB00 FA11 FB05 3G301 HA00 HA01 JA02 JA21 KA11 LA03 MA11 NA08 PA11Z PD02Z PE03Z PE08Z PF03PF01 PC06 PG04 PI16 PI24 PI29 PO02 PO06 PO09 PU22 PU23 PU25 PU29 PV09 QN03 QN27 RB21 RE05 RE06 SE04 SE05 SE06 SE09 TB10 TE02 TE08 TE10 TO21 TO23

Claims (3)

[Claims] 1. An internal combustion engine, a rotating electric machine that also serves as an electric motor and generates power using the internal combustion engine as a power source, and a secondary battery that stores power generated by the rotating electric machine and supplies power to the rotating electric machine A drive control device for a vehicle, comprising: a drive power command value output to the internal combustion engine and the rotary electric machine in accordance with an accelerator operation amount; The value obtained by subtracting the upper limit of the performance of the electric motor or the value obtained by adding the value obtained by limiting the difference between the required driving force and the current internal combustion engine command value to a predetermined value or less to the current internal combustion engine command value, whichever is larger, A drive control device for a vehicle, wherein a command value to the electric machine is a value obtained by subtracting the command value to the internal combustion engine from a required driving force. 2. The drive control device for a vehicle according to claim 1, wherein the command value to the internal combustion engine is at least one of an air amount supplied to the internal combustion engine and a fuel injection amount. . 3. The drive control device according to claim 1, wherein the command value to the rotating electric machine is at least one of a current and a voltage supplied to the rotating electric machine.