JPH1198612A - Controller for hybrid system car - Google Patents

Abstract

PROBLEM TO BE SOLVED: To enhance the performance of a hybrid system car by performing optimum control of a motor generator and an engine. SOLUTION: In a hybrid-system car controller provided with a motor- generator is connected to an engine 10, a torque-distributing means 20 for setting target torque values for the engine 10 and the motor generator 15 on the basis of the condition of operation, and a controller 20 which controls the output of the engine 10 on the basis of the target torque value for the engine 10, and controls the motor generator 15 on the basis of the target torque value for the motor generator 15 as well, the variation of an indicated torque to a target torque value for the motor generator 15 is set according to the condition of the motor generator 15 and the target torque value for the motor generator 15.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a control device for a hybrid system vehicle in which an engine and a motor generator are combined.

[0002]

2. Description of the Related Art Conventionally, a hybrid vehicle in which an engine and an electric motor (motor generator) are combined to improve exhaust emission has been known, for example, Japanese Patent Application Laid-Open No. Hei 3-121928.

[0003] This is a parallel type hybrid system in which an engine and an electric motor are arranged in parallel. Under predetermined running conditions, the vehicle travels by adding the driving force of the electric motor to the driving force of the engine. It is intended to improve the thermal efficiency and exhaust emission of the engine by performing energy regeneration using the motor as a generator, and when driving the electric motor, variably control the distribution of the driving torque between the engine and the electric motor, The engine is controlled so that the thermal efficiency and exhaust emission of the engine are in the best condition.

[0004]

In such a conventional control device for a hybrid system vehicle, the response of the electric motor is not linearly controlled. That is, when controlling the electric motor to the target torque, if the command torque is rapidly increased, hunting may occur at a high torque as shown in FIG. for that reason,
The torque is increased by making the change in the indicated torque gradual.

[0005] However, in this case, if the amount of change in the instruction torque is kept constant, a satisfactory response of the electric motor is not always obtained, resulting in insufficient acceleration during acceleration. Also,
Similarly, there is a problem that a brake shortage during regeneration and a collection of regenerative electric energy are insufficient.

The present invention solves such problems by performing optimal control of an electric motor and an engine.
The purpose is to improve the performance of hybrid system vehicles.

[0007]

According to a first aspect of the present invention, there is provided a motor generator connected to an engine, torque distribution means for setting a target torque value of the engine and the motor generator based on an operating state, and a target torque value of the engine. And a controller that controls the motor generator based on the target torque value of the motor generator while controlling the output of the engine based on Accordingly, the amount of change of the command torque to the torque target value is set.

In a second aspect based on the first aspect, delay detecting means for detecting a delay of an actual torque of the motor generator with respect to a command torque value of the motor generator,
An instruction torque change amount changing means for changing the change amount of the instruction torque based on the delay is provided.

In a third aspect based on the first aspect, there is provided a command torque change amount changing means for changing the change amount of the command torque in accordance with the state of the engine.

In a fourth aspect based on the first aspect, the torque distribution means relatively increases the target torque value of the engine during warm-up of the engine and relatively decreases the torque target value of the motor generator. .

[0011]

According to the first aspect of the present invention, it is possible to obtain an optimum instruction torque to the torque target value of the motor generator, secure a high response of the motor generator during power running, and improve the starting and acceleration performance. . In addition, good braking performance can be secured during deceleration, and energy regeneration performance can be improved.

According to the second aspect, a higher response of the motor generator can be ensured.

According to the third aspect, a response of the motor generator suitable for the engine can be obtained when the engine is warmed up, and the engine can be maintained in a normal state.

According to the fourth aspect, the warm-up performance is improved.

[0015]

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

As shown in FIG. 1, an engine 10 transmits a driving force to a driving shaft 12, a differential device 13, and driving wheels 14 via an automatic transmission 11.

A motor generator 15 arranged in parallel with the engine 10 is connected to a pulley 18 of the engine 10 via a pulley 16 and a belt 17, and the torque generated by the motor generator 15
Is transmitted from the transmission 11 to the drive shaft 12 through
When the vehicle decelerates, the battery 19 is charged by regenerating energy from the drive shaft 12 via the engine 10.

The motor generator 15 is provided with the engine 10
When the engine is started, it operates as a starting means for cranking the engine 10. On the other hand, when predetermined operating conditions such as starting or accelerating the vehicle are satisfied, the torque of the motor generator 15 is added to the torque of the engine 10 to start. , Acceleration and the like are performed smoothly.

Here, the torque distribution between the engine 10 and the motor generator 15 at the time of starting or accelerating the vehicle is as follows.
It is controlled by the control unit 20. The control unit 20 includes an accelerator opening sensor 30 for detecting an accelerator pedal opening (depressed amount) ACS in order to detect a driving state of the vehicle, and a vehicle speed sensor for detecting a vehicle speed VSP from the rotation speed of the drive shaft 12 and the like. The signal from 31 is input. Further, a rotation speed sensor 32 for detecting the rotation speed of the engine 10, a torque sensor 33 for detecting the torque of the engine 10, a temperature sensor 34 for detecting a cooling water temperature (or oil temperature) of the engine 10, and a rotation of the motor generator 15. Signals from a rotation speed sensor 35 for detecting the number, a torque sensor 36 for detecting the torque of the motor generator 15, and the like are input.

The control unit 20 determines the driving state from the detected vehicle speed VSP and the accelerator opening ACS, and if the vehicle is in the starting or accelerating state, the target torque to be output to the transmission 11 based on a predetermined map. After obtaining the output torque target value T * all, which is a value, based on the vehicle speed VSP using the accelerator opening ACS as a parameter, the motor torque target value T _M which is the target value of the torque to be generated by the motor generator 15 from a predetermined map. * _Find (T _TARGET ). Similarly, an engine torque target value _TE *, which is a target value of the torque to be generated by the engine 10, is obtained from a predetermined map based on the output torque target value T * all.

The engine control unit 21 of the control unit 20 performs fuel injection control, ignition timing control and the like of the engine 10 based on the engine torque target value T _E *, and the actual engine which the engine 10 provides to the transmission 11 controls to match the torque T _E to the engine torque target value T _E *.

The motor generator control section 22 of the control unit 20 uses the inverter 23 based on the motor torque target value T _M * to charge the battery 1.
9 is supplied to the motor generator 15, and the actual motor torque T _M applied by the motor generator 15 to the transmission 11 via the engine 10 is changed to a motor torque target value T _M.
Control to match *.

In this case, the motor generator control section 22 controls the instruction torque to the motor torque target value T _M *, that is, the change amount t of the instruction torque for controlling the power supplied from the inverter 23 to the motor generator 15.
And controls the ₁ (time constant), and controls so as to match the target value T _M * of the motor torque T _M with high response.

Next, the contents of control performed by the control unit 20 (motor generator control unit 22) will be described with reference to the flowchart of FIG. This flowchart is executed immediately after the calculation of each torque target value, and is executed, for example, every several milliseconds.

First, in step 1, a motor torque target value T _M * (T _TARGET ) is read.

In step 2, the motor generator 15
While reading the current rotation speed N _NOW and torque T _NOW of
A displacement torque ΔT, which is a difference between the motor torque target value T _TARGET and the current torque T _NOW , is obtained. Based on the displacement torque ΔT, the number of revolutions N _NOW, and the torque T _NOW , a designated torque map is set as shown in FIG. The time constant t ₁ of the indicated torque is read.

The instruction torque map forms a group (A, B,... X) for each predetermined range of the rotation speed N _NOW , the torque T _NOW , and the displacement torque ΔT, and sets the time constant t ₁ ( a, b,... x), and the time constant t ₁ is set smaller on the X side of the group. Also,
For each group, a maximum allowable delay t _{2 serving as} a reference for an instruction torque value and an actual torque delay time when a torque target value in a predetermined range is instructed to the inverter 23 with a corresponding time constant t ₁ .
And the minimum delay t ₃ . The respective time constants t ₁ are basically within a range that does not cause hunting,
It is set to a value that obtains the highest response of the motor generator 15.

When the time constant t ₁ is read from the corresponding group of the indicated torque map, the motor torque target value T _M * is instructed to the inverter 23 at the time constant t _{1 in} step 3. The command torque curve in this case is as shown in FIG.

As a result, the torque of motor generator 15 increases to reach target value T _TARGET . At this time, at step 4, as shown in FIG. Is measured. In this case, the actual torque is checked and measured at a sampling period of several μsec.

In steps 5 to 7, Δt is compared with the maximum allowable delay t ₂ and the minimum delay t ₃ of the corresponding group in the designated torque map from which the time constant t ₁ has been read.

When Δt is t ₃ ≦ Δt ≦ t ₂ , the time constant t
_{Since 1} is appropriate, the process proceeds to step 8, and the selection of the group of the indicated torque map is not changed.

If Δt <t ₃ , the time constant t ₁ is too small, and the routine proceeds to step 9 where the rank of the group to be selected in the designated torque map is reduced.

[0033] Delta] t> when t _2, since the time constant t ₁ is too large, the process proceeds to step 10, to increase the rank of the group to be selected instruction torque map.

The ranks of these groups are changed at the time of the next torque instruction.

Therefore, good and high response of motor generator 15 can be obtained.

Then, in step 11, the engine speed N _E , the torque T _E , the cooling water temperature (or oil temperature) Temp
Is checked, and in steps 12 to 15, the rotational speed N
_E, the torque T _E, perform the rank judgment of a group of instruction torque map by the cooling water temperature Temp.

In this case, as shown in FIG. 6, the minimum temperature limit T of the cooling water temperature Temp is set for each predetermined range of the rotation speed N _E and the torque T _E.
emp (min), standard temperature Temp (Normal), maximum temperature limit Temp (max), etc.
When the cooling water temperature Temp is Temp> Temp (Normal), the rank of the group of the indicated torque map is not changed (steps 16 and 18), and when Temp <Temp (min),
The rank of the group to be selected in the instruction torque map is reduced (step 17).

This rank change is performed at the time of the next torque instruction. At this time, instead of changing the rank, a correction value may be determined and the time constant t ₁ of the corresponding group may be corrected at the next torque instruction. .

Therefore, when the engine 10 is warmed up, a response of the motor generator 15 suitable for the engine can be obtained.

With this configuration, a high response of the motor generator 15 can be obtained during power running without causing hunting in the control, and the starting and acceleration performance is improved.

In this case, the time constant of the indicated torque is changed according to the delay of the actual torque with respect to the indicated torque value of motor generator 15, so that a higher response of motor generator 15 can be obtained.

In addition, when the engine 10 is warmed up, the response of the motor generator 15 suitable for the engine is obtained, and the normal state of the engine 10 with little load fluctuation can be maintained.

Note that the motor generator 15
In this case, the deceleration torque target value T _TARGET is obtained from the vehicle speed VSP or the like, and the current rotation speed N _NOW ,
Torque T _NOW , deceleration torque target value T _TARGET and torque T
Based on the displacement torque ΔT that is the difference from _NOW , read the time constant t ₁ of the indicated torque from the indicated torque map,
The deceleration torque target value T _TARGET is instructed to the inverter 23 at the time constant t ₁ . That is, at the time of regeneration, the target value T _TARGET
Is reduced only, the sign of the displacement torque ΔT is taken and control is performed in the same manner as during power running. Therefore, as shown in FIG. 7, good braking performance can be obtained at the time of deceleration, and energy regeneration performance is improved.

FIG. 8 shows another embodiment of the present invention. When the cooling water temperature (or oil temperature) of the engine 10 is lower than a predetermined value, the engine 10 and the motor generator 15
In this case, the torque distribution is changed.
Based on the coolant temperature, the normal state shown in FIG. 9, the predetermined value α that defines the engine torque target value T _E * by the cooling water temperature plus the torque target value of the motor-generator and correspondingly T _M * Minus from

In this way, the warm-up of the engine 10 can be promoted. During the warm-up, the time constant t ₁ of the instruction torque of the motor generator 15 is increased as described above.

[Brief description of the drawings]

FIG. 1 is a configuration diagram showing a first embodiment.

FIG. 2 is a flowchart showing control contents.

FIG. 3 is a diagram showing an example of a command torque map.

FIG. 4 is a characteristic diagram of a command torque curve.

FIG. 5 is a characteristic diagram showing a command torque and an actual delay.

FIG. 6 is a diagram showing an example of an engine state map.

FIG. 7 is a characteristic diagram showing brake performance and engine regeneration performance.

FIG. 8 is a characteristic diagram of torque distribution according to the second embodiment.

FIG. 9 is a characteristic diagram of torque distribution in a normal state.

FIG. 10 is a characteristic diagram showing control hunting in a conventional example.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Engine 11 Automatic transmission 12 Drive shaft 13 Differential device 14 Driving wheel 15 Motor generator 19 Battery 20 Control unit 21 Engine control part 22 Motor generator control part 23 Inverter 30 Accelerator opening sensor 31 Vehicle speed sensor 32 Speed sensor 33 Torque sensor 34 temperature sensor 35 rotation speed sensor 36 torque sensor

Claims (4)

[Claims] 1. A motor generator connected to an engine, torque distribution means for setting torque target values of the engine and the motor generator based on an operation state, and controlling output of the engine based on the torque target value of the engine. A controller for controlling a motor generator based on a target torque value of the motor generator, the control device for a hybrid system vehicle comprising: a command torque to the target torque value according to the state of the motor generator and the target torque value of the motor generator; A control device for a hybrid system vehicle, characterized by setting a variation amount of the vehicle. 2. A delay detecting means for detecting a delay of an actual torque of the motor generator with respect to a command torque value of the motor generator, and a command torque change amount changing means for changing a change amount of the command torque based on the delay. The control device for a hybrid system vehicle according to claim 1 provided. 3. The hybrid system vehicle control device according to claim 1, further comprising an instruction torque change amount changing unit that changes the change amount of the instruction torque according to an engine state. 4. The hybrid system vehicle according to claim 1, wherein the torque distribution unit relatively increases the target torque value of the engine during warm-up of the engine and relatively decreases the target torque value of the motor generator. Control device.