JP2010168007A - Driving control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a driving control device for quickly passing a resonance band in cranking an engine. <P>SOLUTION: When the start request of an engine 2 is made from a traveling state that the driving of only a motor 3 is controlled (steps S3 and S4: "Yes"), a clutch 4 is connected (step S6), and the cranking of the engine 2 in a stop state is started according to the rotation of front wheels 1FL and 1FR. In this case, when an engine revolving speed Ne is lower than a prescribed value th, the transmission gear ratio of a transmission 5 is controlled to a start transmission gear ratio which is set to a higher side than a normal transmission gear ratio according as a vehicle speed V is low (step S8). Meanwhile, the driving force of the motor 3 is deprived by cranking torque so that motor torque is increased/corrected only by prescribed quantity ΔT equivalent to the cranking torque (step S9). <P>COPYRIGHT: (C)2010,JPO&INPIT

Description

  The present invention relates to a drive control apparatus having two drive sources of an engine and a motor.

  In a hybrid vehicle having two drive sources, an engine and a motor, when the engine is started from a state where the motor is running alone (cranking), the speed ratio is adjusted so that the engine can be started at a rotational speed. However, there is one that engages a clutch between the engine and the transmission (see Patent Document 1).

JP 2003-165358 A

By the way, in the engine rotation, a resonance band exists in a region lower than the idling rotation speed. Accordingly, when the engine speed is increased by cranking, unless the resonance band is passed quickly, the time during which the engine vibration increases becomes longer, and the driver feels uncomfortable.
An object of the present invention is to quickly pass a resonance band when cranking an engine.

  In order to solve the above problems, a drive control device according to the present invention calculates a target drive force in accordance with a driver's accelerator operation, and drives and controls at least one of the engine and the motor in accordance with the target drive force. When driving the engine, the normal gear ratio is calculated according to the target driving force, the transmission is shifted according to the normal gear ratio, and the clutch is connected. Only the motor is driven and controlled. When the engine is started in a state where the transmission is in a state, the transmission is shifted to a higher side than the normal gear ratio.

  According to the present invention, when the engine is started in a state where only the motor is driven and controlled, that is, when cranking, a larger cranking torque is obtained by shifting the transmission to a higher side than the normal gear ratio. Is obtained. Therefore, since the engine speed can be increased smoothly and the resonance band can be passed quickly, the time during which the engine vibration increases can be shortened and the uncomfortable feeling can be reduced.

It is a schematic structure of HEV. It is a flowchart which shows a calculation process. It is a map used for calculation of a start gear ratio. It is a time chart explaining operation | movement of this embodiment.

Hereinafter, embodiments of the present invention will be described with reference to the drawings.
<Embodiment>
"Constitution"
FIG. 1 shows a schematic configuration of a HEV (Hybrid Electric Vehicle), which is a hybrid vehicle in which front wheels 1FL and 1FR are driven by an engine 2 and rear wheels 1RL and 1RR are driven by a motor 3.
The engine 2 transmits the output to the front wheels 1FL and 1FR through the clutch 4 and the transmission 5 in order, and the motor 3 transmits the output to the rear wheels 1RL and 1RR through the reduction gear and the clutch (not shown) in order. .
The transmission 5 shifts power between the engine 2 and the front wheels 1FL and 1FR, and the clutch 4 interrupts power between the transmission 5 and the front wheels 1FL and 1FR. The clutch 4 only needs to be able to arbitrarily adjust the transmission torque, and may take any form such as one using electromagnetic force, hydraulic pressure, air pressure, wet type, dry type, powder type, single plate type, or multi-plate type.

The motor 3 is capable of power running and regeneration, and drives the rear wheels 1RL and 1RR with the electric power of the high voltage battery 6 at the time of power running. At the time of regeneration, the high voltage battery 6 is driven by the rotational energy of the rear wheels 1RL and 1RR in the rotating state. To charge. For example, when there is a quick acceleration request or when a slip tendency of the front wheels is detected, a power running operation is performed, and when there is a deceleration request or a braking operation, a regenerative operation is performed.
The controller 11 inputs the accelerator opening Acc detected by the accelerator sensor 12 and the vehicle speed V detected by the vehicle speed sensor 13, and controls each of the engine 2, the motor 3, the clutch 4, and the transmission 5.

Next, arithmetic processing executed by the controller 11 will be described with reference to the flowchart of FIG.
In step S1, the target driving force of the vehicle is calculated according to the accelerator opening Acc.
In the subsequent step S2, at least one of the engine 2 and the motor 3 is driven and controlled according to the target driving force.
In subsequent step S3, it is determined whether or not the engine 2 has a drive request. If there is no drive request for the engine 2, the process returns to the predetermined main program as it is. On the other hand, if the engine 2 has a drive request, the process proceeds to step S4.

In step S4, it is determined whether or not the motor 3 has a drive request. If there is no drive request for the motor 3, it is determined that cranking of the engine 2 by the motor 3 is impossible, and the process proceeds to step S5. On the other hand, if there is a drive request for the motor 3, it is determined that the cranking of the engine 2 by the motor 3 is possible, and the process proceeds to step S7 described later.
In step S5, a normal gear ratio is calculated according to the accelerator opening degree Acc and the vehicle speed V, and gear shift control is performed according to the normal gear ratio.

In the subsequent step S6, the clutch 4 is connected and controlled, and the process returns to the predetermined main program.
In step S7, it is determined whether or not the engine speed Ne is greater than a predetermined value th. The predetermined value th varies depending on vehicle specifications, but is a value that is at least larger than the upper limit value of the resonance band, and is, for example, about 800 to 1000 rpm. If the determination result is Ne> th, it is determined that the resonance band has already been exceeded and a complete explosion has occurred, and the process proceeds to step S5. On the other hand, if the determination result is Ne ≦ th, it is determined that the resonance band has not been exceeded and the complete explosion has not occurred, and the process proceeds to step S8.

In step S8, first, referring to the map of FIG. 3, a start speed ratio for cranking the engine 2 is calculated according to the vehicle speed V, and speed change control is performed according to this start speed ratio. This map shows that when the vehicle speed V is less than or equal to a predetermined value V1 in the low speed range, the speed ratio maintains a predetermined maximum value _RMAX , and the speed ratio increases to a predetermined maximum value R as the vehicle speed V increases from the predetermined value V1. It is set to decrease from _MAX . The starting speed change ratio calculated in this way is a value on the higher side than the above-described normal speed change ratio. The maximum value R _MAX does not necessarily indicate the top gear.
In subsequent step S9, the driving torque of the motor 3 is corrected to be increased by a predetermined amount ΔT, and then the process proceeds to step S6. The predetermined amount ΔT is a value corresponding to the cranking torque necessary for cranking the engine 2.

<Action>
FIG. 4 is a time chart for explaining the operation of the present embodiment.
First, it is assumed that a start request for the engine 2 is made by a large depression of the accelerator pedal from a state in which only the motor 3 is driven and controlled (both steps S3 and S4 are “Yes”). At this time, since the vehicle is already running by driving the motor, the clutch 4 starts to be connected from time t1 (step S6), and the cranking of the engine 2 in the stopped state is started by the rotation of the front wheels 1FL and 1FR. .
By the way, in the engine rotation, a resonance band exists in a region lower than the idling rotation speed. Therefore, when the rotation speed of the engine 2 is increased by cranking, unless the resonance band is passed quickly, the time during which the vibration of the engine 2 increases becomes longer, which gives the driver a feeling of strangeness.

Therefore, in the present embodiment, a large cranking torque is obtained by controlling the gear ratio of the transmission 5 to a starting gear ratio that is higher than the normal gear ratio (step S8). Immediately after time t1, since the engine speed Ne is lower than the predetermined value th, the start gear ratio is calculated according to the vehicle speed V according to the map of FIG. 3, so that while the vehicle speed V is equal to or lower than the predetermined value V1, the maximum The value R _MAX is maintained, and in FIG. 4, the gear ratio is larger by a than the normal gear ratio. In this way, since the rotational speed of the engine 2 can be increased smoothly and can pass through the resonance band quickly, the time during which the engine vibration increases can be shortened and the uncomfortable feeling can be reduced.

When the vehicle speed V exceeds the predetermined value V1 at time t2, thereafter, the starting gear ratio as the vehicle speed V increases decreases from a predetermined maximum value R _MAX. As described above, the lower the vehicle speed V, the higher the start gear ratio, so that a situation where the engine speed Ne does not increase due to the low vehicle speed V can be avoided.
On the other hand, since the driving force of the motor 3 is lost by the cranking torque, the motor torque is corrected to be increased by a predetermined amount ΔT corresponding to the cranking torque (step S9). Thereby, the target driving force according to the accelerator opening Acc can be achieved without reducing the total driving force of the vehicle.

At subsequent time t3, when the engine speed Ne exceeds the predetermined value th (determination in step S7 is “Yes”), it is determined that the engine has passed the resonance band and the complete explosion has occurred, and the gear ratio is changed to the normal gear ratio. (Step S5). Thereby, the burden with respect to the started engine 2 can be reduced. However, since a shock is generated when the speed difference from the start speed ratio to the normal speed ratio is large, a smooth shift is made by gradually shifting from the start speed ratio to the normal speed ratio.
In addition, after the engine is completely detonated, the cranking torque becomes useless, so the motor torque increase correction is terminated. Thereby, useless energy loss can be avoided.

《Application example》
In the present embodiment, the clutch 4 and the transmission 5 are described as separate bodies. However, the present invention is not limited to this, and an integrated configuration such as an automatic transmission may be used. In this case, the torque converter included in the automatic transmission corresponds to the “clutch”.
Further, the front wheels 1FL and 1FR are driven by the engine 2 and the rear wheels 1RL and 1RR are driven by the motor 3. However, the present invention is not limited to this, and the rear wheels 1RL and 1RR are driven by the engine 2 and the front wheels are driven. 1FL · 1FR may be driven by the motor 3.
Further, although power is supplied from the battery 6 to the motor 3, the power supply is not limited to this, and power may be supplied from a capacitor or a generator.
Moreover, although it is set as the power train of 1 motor system which drives rear-wheel 1RL * 1RR with one motor 3, the 2 motor system which drives each wheel with two motors, or the wheel which uses the motor itself as a driving wheel An in-motor system may be used.

"effect"
From the above, the front wheels 1FL and 1FR correspond to the “first wheel”, the rear wheels 1RL and 1RR correspond to the “second wheel”, and the processing of steps S1, S2, and S9 is changed to the “drive source control means”. Correspondingly, the processes of steps S3 to S6 and S8 correspond to “power transmission control means”.
(1) an engine for driving a first wheel, a transmission for shifting power between the first wheel and the engine, a clutch for intermittently driving power between the transmission and the engine, and a second A motor that drives the wheels of the vehicle, a drive source control means that calculates a target drive force according to the driver's accelerator operation, and drives and controls at least one of the engine and the motor according to the target drive force, and the drive When the source control means controls the drive of the engine, it calculates a normal gear ratio according to the target drive force, shifts the gear according to the normal gear ratio, and controls the connection of the clutch. Transmission control means, and the power transmission control means is higher than the normal gear ratio when the engine is started with the drive source control means driving only the motor. Shifting controls the speed ratio.
As a result, a large cranking torque can be obtained, so that the rotational speed of the engine can be increased smoothly, the resonance band can be quickly passed through, and the time during which the engine vibration increases can be shortened to reduce discomfort.

(2) The power transmission control means shifts the transmission to a higher side than the normal gear ratio as the vehicle speed is lower.
As a result, it is possible to avoid a situation in which the engine speed does not increase due to the low vehicle speed.
(3) When the rotational speed of the engine becomes higher than a predetermined value, the power transmission control means ends the shift to the higher side than the normal gear ratio.
Thereby, the burden on the started engine can be reduced.

1FL · 1FR Front wheel 1RL · 1RR Rear wheel 2 Engine 3 Motor 4 Clutch 5 Transmission 11 Controller 12 Accelerator sensor 13 Vehicle speed sensor

Claims (3)

An engine for driving the first wheel, a transmission for shifting power between the first wheel and the engine, a clutch for intermittently transmitting power between the transmission and the engine, and a second wheel. A driving motor;
Drive source control means for calculating a target driving force according to the driver's accelerator operation, and driving and controlling at least one of the engine and the motor according to the target driving force;
When the drive source control means controls driving of the engine, a normal gear ratio is calculated according to the target driving force, and the transmission is controlled to shift according to the normal gear ratio, and the clutch is controlled to be connected. Power transmission control means for
The power transmission control means shifts the speed ratio to a higher side than the normal speed ratio when the engine is started with the drive source control means driving only the motor. A drive control device characterized by the above.   2. The drive control device according to claim 1, wherein the power transmission control unit shifts the transmission to a higher side than the normal gear ratio as the vehicle speed is lower.   3. The drive control device according to claim 1, wherein the power transmission control unit finishes shifting to a higher side than the normal gear ratio when the rotational speed of the engine becomes higher than a predetermined value. 4. .

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