JP2000272381A - Running control system for vehicle - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a vehicle control system in a vehicle installed with a CVT, which does not give uncomfortable feels to occupants during deceleration by preventing extreme increase of deceleration change at the decelerating state. SOLUTION: If an ECU 30 recognizes fuel cut control at the decelerating state by accelerator pedal OFF, it calculates a target throttle opening based on speed reduction ratio or vehicle speed of a CVT 12 so as to control opening of a throttle actuator 40 to cancel the increase of deceleration force due to shifting of the CVT 12 to the Lo side. At the same time, the ECU 30 detects the drive condition of an air conditioning 52 and calculates the load correction ratio of the air conditioning 52 corresponding to the speed reduction ratio of the CVT 12 or vehicle speed for suppressing the driving for the air conditioning 52. Load for an engine 10 is thus reduced, increase of deceleration force due to engine friction increase is prevented. As a result, change in the deceleration force is restricted, which does not give uncomfortable feels to occupants.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a travel control device for a vehicle, and more particularly, to a travel control device for a vehicle equipped with an engine and a continuously variable transmission, which eliminates an uncomfortable feeling of sudden deceleration due to an engine braking phenomenon.

[0002]

2. Description of the Related Art Conventionally, a continuously variable transmission (hereinafter referred to as a CVT-Continuo) capable of continuously controlling a transmission gear ratio.
There is a vehicle equipped with usly Variable Transmission-). The CVT has attracted particular attention in recent years because it can perform a smooth shift operation, sufficiently utilize characteristics of an engine, and improve exhaust gas and fuel efficiency.

[0003] Further, Japanese Patent Publication No. 7-12807 and the like disclose that when the vehicle is running at a reduced speed, the engine speed is reduced below a predetermined fuel cut lower limit speed.
Some include a fuel cut device that shuts off fuel to be supplied to the engine. In such a vehicle, fuel is not consumed at the time of decelerating running that does not require the output of the engine, so that the running fuel efficiency of the vehicle is improved. Since the effect of improving the running fuel efficiency increases as the fuel cut range increases, it is desired to set the fuel cut lower limit rotational speed as low as possible. In order to realize this, for example, while fuel supplied to the engine is shut off, a lock-up clutch for mechanically connecting and disconnecting power between the engine and the drive wheels is engaged (connected). The engine can be rotated by transmitting the running force of the vehicle to the engine via the lock-up clutch as a state. At this time, if the vehicle is equipped with a CVT, the gear ratio can be easily changed to Lo even if the vehicle speed continues to decrease.
Side, the engine speed can be maintained at the fuel cut lower limit speed for a certain period of time, and the substantial period in which fuel cut is possible can be increased to improve fuel economy.

When the engine speed falls below the fuel cut lower limit speed, the lock-up clutch is disengaged (disengaged) and the engine is free of drive wheels (only the fluid of the torque converter). Connection state), fuel injection to the engine is restarted, and the engine is driven autonomously to maintain idling rotation. When the accelerator is depressed, the output of the engine is increased and the lock-up clutch is connected again to transmit the output of the engine to the drive wheels.

[0005]

Generally, when the accelerator pedal is turned off and the vehicle is in a deceleration state (the engine is driven by driving wheels, that is, an engine braking state), the deceleration force of the vehicle changes due to the friction of the engine. I do. Vehicles with fixed (discontinuous) gear ratios during deceleration (general M / T vehicles and A / T vehicles without CVT)
In the case of, the engine speed decreases with decreasing vehicle speed,
The friction is accordingly reduced, so that the vehicle is gradually decelerated without feeling uncomfortable. However, in a vehicle equipped with a CVT, if the gear ratio is shifted to the Lo side during deceleration in order to efficiently perform the fuel cut control, the engine speed becomes constant and the friction becomes constant.
The deceleration force increases by the change in the gear ratio of the CVT. At this time, there is a problem that the driver feels uncomfortable because the deceleration force increases (deceleration change amount increases) even though the driver does not perform any operation other than the accelerator pedal OFF (operation of the brake pedal, etc.). .

Further, the CVT cannot change the reduction ratio unless the drive wheels are rotating, so that the reduction ratio is shifted to the maximum Lo side by the time the vehicle stops, regardless of the presence or absence of the fuel cut control. It is necessary to prepare for the restart of the vehicle, so the engine speed is maintained during deceleration and the CV
Since the gear ratio of T shifts to the Lo side, the same problem as described above occurs.

SUMMARY OF THE INVENTION The present invention has been made in view of the above problems, and provides a vehicle travel control device capable of preventing an extreme increase in deceleration change when a CVT-equipped vehicle is in a deceleration state due to an accelerator pedal OFF. The purpose is to provide.

[0008]

In order to achieve the above object, a first aspect of the present invention is arranged between an engine and the engine and driving wheels to continuously change a gear ratio. And a continuously variable transmission,
In the case where the engine is driven by the drive wheels while increasing the reduction ratio of the continuously variable transmission to obtain the coasting deceleration force of the vehicle, there is provided an adjusting means for adjusting the engine friction so that the deceleration change amount of the vehicle is within a predetermined value. It is characterized by doing.

Here, the coasting deceleration force is a deceleration force generated when a so-called engine braking operation is performed without operation of a brake pedal or the like. In addition, the engine friction is a frictional resistance due to the rotation of the engine,
In addition to the frictional resistance due to the rotation of the engine related to traveling, the frictional resistance due to the rotation increase due to the load when the engine drives the external device is included. Further, the deceleration change amount of the vehicle being within a predetermined value is, for example, a deceleration force within 800 N. According to this configuration, even when the reduction ratio of the continuously variable transmission that affects the magnitude of the coasting deceleration force increases with the vehicle deceleration, the engine friction that affects the fluctuation of the deceleration force can be adjusted. Adjustment of the deceleration force, that is, adjustment of the amount of change in deceleration, becomes possible, and smooth deceleration can be performed without giving a feeling of strangeness to the vehicle occupant.

In order to achieve the above object, a second invention includes an engine and a continuously variable transmission arranged between the engine and drive wheels and capable of continuously changing a gear ratio. In a vehicle travel control device, when obtaining a coasting deceleration force due to an engine driven by a drive wheel while increasing a reduction ratio of a continuously variable transmission and a forced deceleration force due to a brake operation of a vehicle driver, a deceleration of the entire vehicle is performed. An adjusting means for adjusting the engine friction so that the change amount is within a predetermined value is provided.

According to this configuration, even when the forced deceleration by the brake operation is performed, the coasting deceleration force is controlled, so that the amount of deceleration by the driver's brake operation can be obtained, and the driver and the vehicle can be obtained. Smooth deceleration that does not give a feeling of discomfort to the passenger can be performed.

According to a third aspect of the present invention, in the first or second aspect, the adjusting means performs at least one of an engine boost pressure control and an auxiliary device drive control. It is characterized by adjusting the engine friction.

Here, the boost control is a control for adjusting the engine friction by controlling an intake air amount of the engine, and the auxiliary drive control is a control for an engine such as an alternator or a compressor of an air conditioner or a motor generator. This is control of equipment that causes a load. According to this configuration, it is possible to reduce the load on the engine by performing the boost pressure control and the auxiliary drive control of the engine, so that the friction of the engine can be easily adjusted and the deceleration change amount can be adjusted appropriately. Control can be performed.

[0014]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention (hereinafter referred to as embodiments) will be described below with reference to the drawings.

Embodiment 1 FIG. 1 shows a conceptual configuration diagram of a vehicle according to Embodiment 1 of the present invention. The vehicle targeted in the first embodiment has a continuously variable transmission (CVT) 12 disposed between an engine 10 and driving wheels (not shown). 1, a crankshaft 10a of an engine 10 is connected to an input shaft 12a of a belt type CVT 12 via a torque converter 18 having a forward / reverse switching mechanism 14 and a lock-up clutch 16. The output shaft 12b of the CVT 12 is connected to driving wheels of the vehicle via a differential gear device or the like (not shown). When the lock-up clutch 16 is mechanically connected (engaged), the torque of the engine 10 can be transmitted to the drive wheels, and the torque of the drive wheels can be transmitted to the engine 10. Also, lock-up clutch 1
When the engine 6 is disconnected (disengaged), the engine 10
Side and the drive wheel (CVT 12) side become independent (the fluid connection is made by the torque converter 18), and the engine 1
A value of 0 enables autonomous driving without receiving an excessive load on the driving wheel side, for example, it is possible to maintain idling rotation.

The CVT 12 shown in FIG.
a and a pair of variable pulleys 2 composed of a fixed rotating body 20b
The gear ratio is changed by changing the groove width of the belt 22 around these variable pulleys 20 by changing the groove width of the groove 22 by hydraulic pressure so that the tension is maintained constant. The change speed becomes the shift speed. Accordingly, the hydraulic control for supplying and discharging the actuator 24 for driving the movable sheave in each variable pulley 20 allows
The shift speed can be arbitrarily controlled. In addition, CV
As T, a toroidal type in which a power roller is sandwiched between a pair of disks having a toroidal surface, and the power roller is tilted to change the radius of a point of contact with the disk to change the speed can be used.

Further, the torque converter 18 basically operates the engine 1 even when the vehicle is stopped.
0 is operated intermittently.
The forward / reverse switching mechanism 14 is provided because the rotation direction of the engine 10 is limited to one direction and the CVT 12 does not have a reversing operation mechanism, and is a mechanism mainly composed of a planetary gear mechanism. And a mechanism including a reverse gear and a synchronous connection mechanism.

Rotation speed sensors 26 and 28 for detecting the rotation speed of the input shaft 12a and the output shaft 12b, respectively.
Is provided. These rotation speed sensors 26, 28
Is connected to an electronic control unit (hereinafter, referred to as ECU) 30 mainly composed of a microcomputer,
The ECU 30 calculates the gear ratio of the CVT 12 based on the detection signals of the rotation speed sensors 26 and 28.

An intake pipe of the engine 10 is provided with an air quantity sensor 32 for detecting an intake air quantity, and a rotation sensor 34 for detecting an engine rotation speed is provided near the crankshaft 10a. The ECU 30 optimally controls the fuel injection amount and the ignition timing according to the intake air amount detected by the air amount sensor 32 and the engine speed detected by the rotation sensor 34.

On the other hand, an accelerator sensor 38 for detecting the accelerator opening is provided near the accelerator pedal 36, and provides the ECU 30 with the detection result. ECU 30
Is the accelerator opening detected by the accelerator sensor 38,
Based on the vehicle speed detected by the rotation speed sensor 28 and the engine rotation speed detected by the rotation speed sensor 34, the amount of intake air is controlled through the throttle actuator 40 so that, for example, fuel economy is optimized.

The shift lever 42 provided in the vicinity of the driver's seat is provided with a shift sensor 44 for detecting the operating position of the shift lever. Information and vehicle speed,
The lock-up clutch 1
6 and the gear ratio of the CVT 12 are controlled.

Further, a brake pedal sensor 48 for detecting the operation amount and operation speed of the brake pedal is provided near the brake pedal 46. The brake pedal sensor 48 is arranged on the brake pedal bracket, and outputs a voltage proportional to the amount of depression of the brake pedal as an EC.
Provide to U30.

A fuel cut device (computer) 50 is further connected to the ECU 30. The fuel cut device 50 uses the lock-up clutch 16 during deceleration traveling of the vehicle to mechanically connect the CVT 12 rotating by driving of drive wheels and the engine 10 to the predetermined vehicle traveling state. This shuts off the fuel supplied to the vehicle. Here, the vehicle running state is, for example, a predetermined fuel cut lower limit value (for example, when determined by an engine speed, 500
rpm, vehicle speed, 15 km / h, etc.).
In this way, the fuel consumption of the vehicle is improved by preventing the fuel from being consumed during the deceleration running that does not require the output of the engine 10. The ECU 3
0 is set so that the engine speed is maintained at a predetermined value or more in order to extend the fuel cut possible period as much as possible.
Control for continuously increasing the speed reduction ratio of the VT 12 (shifting to the Lo side) is performed. Further, when the state of the engine 10 becomes equal to or less than the fuel cut lower limit, the fuel cut device 50 sets the lock-up clutch 1
6 is disconnected (released) to make the engine 10 free with respect to the drive wheels (a state connected only by the fluid of the torque converter 18), and the fuel injection to the engine 10 is restarted to drive the engine 10 autonomously. This keeps the idling rotation. When the accelerator pedal 36 is depressed, the ECU 30 increases the output of the engine 10, connects the lock-up clutch 16 again, transmits the output of the engine 10 to the drive wheels via the CVT 14, and Perform acceleration.

Further, an air conditioner (hereinafter, referred to as an air conditioner) 52, which is an auxiliary device, is connected to the ECU 30 to control the driving thereof. The compressor and the like of the air conditioner 52 are driven by the engine 10. Although FIG. 1 shows the ECU 30 and the fuel cut device 50 as separate components, the ECU 30 and the fuel cut device 50 may be configured with a single ECU.

Incidentally, the deceleration force of the vehicle increases as the friction of the engine 10 increases. At this time, CVT12
When the speed reduction ratio shifts to the Lo side, the rotational speed of the engine is maintained at a predetermined value, so that the friction based on the running of the engine 10 in the vehicle does not change, and the deceleration force becomes constant. Further, the deceleration force increases as the reduction ratio of the CVT 12 increases (shifts to the Lo side). In other words, the deceleration force of the vehicle as a whole increases rapidly as the deceleration proceeds and the reduction ratio increases. This sudden increase in the amount of deceleration change causes a great discomfort for the vehicle occupant.

The characteristic feature of the first embodiment is that the amount of deceleration change of the vehicle is controlled by adjusting the engine friction during the so-called engine braking operation, in which the engine is driven by the drive wheels to obtain the coasting deceleration force. In addition, even when the reduction ratio of the continuously variable transmission increases, the deceleration force is prevented from suddenly increasing (change in the amount of change in deceleration), so that the vehicle occupant does not feel uncomfortable.

FIG. 2 shows a control procedure when the vehicle is decelerated only by coasting deceleration (engine brake) in the first embodiment. In the first embodiment, a case will be described in which the fuel cut control is also used, and the speed reduction ratio positively shifts to the Lo side during deceleration.

The ECU 30 constantly detects the state of the vehicle to adjust the engine friction during deceleration. First, the ECU 30 detects whether or not the lock-up clutch 16 is ON (S100). When the lock-up clutch 16 is ON, the ECU 30
Determines whether the idle switch is ON (S101). This idle switch is a switch that is turned on when the accelerator pedal 36 is not depressed. That is, if the idle switch is ON,
It indicates that the driver does not have at least the intention to maintain or accelerate the vehicle speed. If it is determined that the idle switch is on,
U30 determines whether or not it is in the fuel cut control state (S102). In this determination, it is determined whether or not the fuel cut is being performed based on information from the fuel cut device 50 and information from the rotational speed sensors 28 and 34 and the like.

In (S100), the lock-up clutch 16
Is off, it is determined that the engine 10 is idling at a predetermined speed or less. Also, (S1
When the idle switch is OFF in 01), it is determined that the accelerator pedal 36 is depressed and the driver is requesting to maintain or accelerate the running speed of the vehicle. Further, when it is determined in (S102) that the vehicle is not in the fuel cut control state, it is determined that the vehicle speed or the rotation speed of the engine 10 is equal to or less than the fuel cut condition, and the vehicle has shifted to the idling state. Thus (S100)-
If a negative determination is made in (S102), the ECU 30
The target throttle opening is calculated in the determined normal control (S103), and the ECU 30 outputs a control amount based on the calculated target throttle opening (S10).
4). For example, when it is determined that the engine is in the idling state, the ECU 30 controls the engine 10 to perform only intake of air necessary for idling from an idle bypass (not shown), fully closes the throttle actuator 40 to perform main intake of air. The throttle is fully closed so as to stop. When the accelerator pedal 36 is depressed, the throttle actuator 40 is controlled according to the accelerator opening based on the detection result of the accelerator sensor 38.
The throttle opening / closing output is performed so that the required amount of air is sucked. The control amount of the throttle actuator 40 at this time is performed, for example, based on a map in which the relationship between the accelerator opening and the throttle opening is predetermined.

On the other hand, when it is determined in (S102) that the vehicle is in the fuel cut state, it is determined that the vehicle shifts to a so-called engine braking operation state in which the vehicle is decelerating while coasting. In this case, the ECU 30 controls the CVT 12
In order to reduce the friction of the engine 10, the CVT 12
The target throttle opening in the current vehicle running state is calculated based on the reduction ratio (gear ratio) of the vehicle, the vehicle speed, and the like (S1).
05). Generally, in the accelerator OFF state, since the throttle actuator 40 is fully closed, air is not sucked in, so that the rotational load of the engine 10 increases and causes friction. In (S105), the slot opening is calculated to reduce the load by adjusting the intake amount of the engine 10. Note that CVT1
Since the reduction ratio of 2 is determined by the rotation speed and the vehicle speed of the engine 10, for example, as shown in FIG. 3A, by preparing a map indicating the relationship between the reduction ratio (gear ratio) and the throttle opening degree, Thus, the throttle opening according to the vehicle state at that time can be easily determined. This control of the throttle opening is what is called boost control of the engine 10, and the friction of the engine 10 can be reduced by this boost control.

In the first embodiment, the ECU 30
Determines whether auxiliary equipment such as the air conditioner 52 that applies a load to the engine 10 is currently in a driving state (S10).
6). When the ECU 30 recognizes the driving of the air conditioner 52, the ECU 30 calculates a load correction factor of the air conditioner 52 (S10).
7). Here, the load correction rate of the air conditioner 52 refers to how much the driving of the air conditioner 52 should be limited in the current running state of the vehicle in order to reduce the load that the engine 10 receives by driving the compressor of the air conditioner 52. Is a value that determines whether or not the CVT1 is appropriate.
The load correction ratio of the air conditioner 52 in the current vehicle running state is calculated based on the speed reduction ratio (gear ratio), the vehicle speed, and the like. As shown in FIG. 3B, by preparing a map showing the relationship between the load correction ratio and the reduction ratio (gear ratio) determined by the rotation speed of the engine 10 and the vehicle speed, the load correction ratio according to the vehicle state can be easily determined. Can be determined. As shown in FIG. 3B, the load correction rate is “1” when the reduction ratio (gear ratio) is on the highest Hi side, and decreases according to the Lo side shift of the gear ratio. I have. When the load correction rate is determined, the ECU 30 integrates the load correction rate with the current load (recognized based on the driving state of the compressor and the like) of the air conditioner 52 that is currently driven, and calculates the load of the air conditioner 52 that is coasting and decelerating (S108). ). Then, in order to reduce an increase in the load on the engine 10 due to the driving of the air conditioner 52, that is, an increase in friction, a load correction value for limiting the driving of the air conditioner 52 is output (S109). In FIG. 4,
In the ECU 30, lock-up, idle switch, fuel cut state determination means 30a (recognized by various sensors, etc.), throttle target opening degree calculation means 30b, and air conditioner load correction rate calculation means 30c related to the first embodiment are included in the ECU 30. Is shown.

Subsequently, the ECU 30 outputs the target throttle opening calculated in (S105) (S104), and controls the throttle actuator 40. As a result, as shown in FIG. 3A, the more the gear ratio shifts to the Lo side, the more the throttle opening shifts in the opening direction.
0 is reduced, the frictional resistance during rotation of the engine 10 is reduced, and the speed reduction ratio of the CVT 12 shifts to the Lo side. Friction can be reduced. Further, at the same time, the driving of the auxiliary equipment such as the air conditioner 52 is limited as the reduction ratio of the CVT 12 shifts to the Lo side, so that the load on the engine 10 is reduced and the friction of the entire engine 10 can be reduced.
As a result, even if the CVT 12 shifts to the Lo side, it is possible to cancel the deceleration force generated thereby, and it is possible to prevent the amount of deceleration change of the vehicle from changing abruptly. In addition, the discomfort of the vehicle occupant can be reduced.

On the other hand, if it is determined that the air conditioner 52 is not operating in (S106), it is determined that the one that gives a large load to the engine 10 is not operating, and (S10)
The process moves to 4), and control based on the target throttle opening calculated in (S105) is performed. That is, the friction control of the engine 10 is performed by the boost control.

As described above, since the load of the engine 10 is adjusted by controlling the intake air amount and controlling the driving of the auxiliary machines, the overall friction of the engine 10 can be adjusted, and the engine braking action can be rapidly reduced. By preventing the change amount from increasing, the deceleration force can be suppressed to, for example, 800 N or less. As a result, the discomfort of the vehicle occupant can be reduced. FIG. 5 shows the relationship between the vehicle speed, the reduction ratio (gear ratio), and the reduction force when the air conditioner load adjustment is performed and when it is not performed. As is clear from the figure, when the air conditioner load was adjusted,
Even when the reduction ratio of the CVT 12 shifts to the lowest Lo side, a sudden increase in the deceleration force is prevented.

In the first embodiment, an example has been shown in which boost control for controlling the throttle actuator 40 and drive control for the air conditioner 52, which is an auxiliary machine, are performed in order to more efficiently avoid a rapid increase in the deceleration force. In either case, an effect of avoiding a sudden increase in the deceleration force can be obtained. In the first embodiment, the air conditioner 52 is taken as an example of the auxiliary device. However, the same effect can be obtained by controlling a device that is driven by the engine 10 such as an alternator and applies a load to the engine 10. .

Embodiment 2 FIG. FIG. 6 shows the engine and CV
Motor generator in addition to T (hereinafter referred to as MG)
Is a conceptual diagram of a drive system configuration of a vehicle including

The engine 60 is provided on one side of an output shaft 60a thereof with an MG 64 via an input casing 62a of a damper 62.
The output of the engine 60 is transmitted to the input shaft 68 via the damper 62. The power entering the input shaft 68 is transmitted to the forward / reverse switching mechanism 70.
The forward / reverse switching mechanism 70 is constituted by a double pinion type planetary gear. When the forward clutch 72 is engaged, the forward / backward switching mechanism 70 integrally rotates and advances. When the reverse brake 74 is engaged, the vehicle enters a reverse state. Forward clutch 72 and reverse brake 7
4 is also used as a starting mechanism. The output from the forward / reverse switching mechanism 70 is transmitted to the input shaft 78 of the CVT 76.

The output shaft 80 of the CVT 76 is connected to a gear type power transmission mechanism 82 composed of a plurality of gear groups. The gear-type power transmission mechanism 82 is connected to a differential 86 connected to an axle 84 having a wheel (not shown) at one end. A housing 88 fixed integrally with the engine 60 is provided around the MG 64, the forward / reverse switching mechanism 70, the CVT 76, the gear-type power transmission mechanism 82, and the differential device 86.

As described above, the MG 64 constituting the power generation / motor means includes a rotor 66 having a rotor core rotating integrally with the output shaft 60a, a cage winding 90 mounted on the rotor core, and a housing 88. And a stator 94 composed of a stator core 92 fixed to the stator core and a stator winding 92 mounted on the stator core. Also MG
An oil pump 96 connected to and driven by the input shaft 68 is provided between the CVT 64 and the CVT 76.

In the MG 64, the rotor 66 functions as a rotor part, and the stator 94 functions as a stator part. Both parts constitute an induction machine. Then, a predetermined frequency voltage is applied to the stator winding 92 of the stator portion to give a rotating magnetic field to the MG 64 to provide a rotating magnetic field having a frequency advanced with respect to the rotation speed of the output shaft 60 a of the engine 60. Thereby, the induction machine can be operated as a generator. And
The starting force is applied to the engine 60 at the time of starting by the rotational driving force by the electric operation, and the driving force is assisted and assisted by the engine 60 during the traveling.

Alternatively, a predetermined frequency voltage is applied to the MG 64 to the stator winding 92 of the stator section to apply a rotating magnetic field, and the MG 64 is rotated at a frequency delayed with respect to the rotation speed of the output shaft 60 a of the engine 60. By using a magnetic field, the induction machine is operated as a generator to perform a power generation operation.

A characteristic feature of the second embodiment is that friction control of the entire engine is performed by controlling the drive regeneration of the MG 64 as an auxiliary machine, and the deceleration force of the vehicle is equalized (corrected to an ideal deceleration state). Then, the vehicle is being smoothly decelerated without a feeling of strangeness.

FIG. 7 shows the coasting deceleration when the MG 64 as an auxiliary machine is controlled (the amount of depression of the brake pedal = 0).
The flowchart explaining the deceleration force control procedure at the time is shown. The engine 60, MG 64, CVT 6 shown in FIG.
7 operate by various processes of the ECU 98 shown in FIG. Further, the throttle actuator (not shown in FIG. 6) and the MG 64 are provided with state determination means 98a such as lock-up, idle switch and fuel cut included in the ECU 98, throttle target opening degree calculation means 98b, and MG drive / regeneration force calculation means 98c. And target deceleration force calculating means 98d
The operation is performed based on the processing results such as the above.

The ECU 98 constantly detects the state of the vehicle to adjust the engine friction during deceleration, as in the first embodiment. That is, the ECU 98 detects whether or not the lock-up clutch (not shown in FIG. 6) is ON (S200), determines whether or not the idle switch is ON (S201), and determines whether or not it is in the fuel cut control state. A determination is made (S202). And (S200) ~
If a negative determination is made in (S202), the ECU 98
As in the first embodiment, the target throttle opening in the determined normal control is calculated (S203), and a control amount based on the calculated target throttle opening is output (S204).

On the other hand, when it is determined in (S202) that the vehicle is in the fuel cut state, it is determined that the vehicle shifts to a so-called engine braking operation state in which the vehicle is decelerating while coasting. In this case, the ECU 98 controls the CVT 12
The target throttle opening in the current vehicle traveling state is calculated based on the reduction ratio (gear ratio) of the vehicle and the vehicle speed (S
205). The throttle opening in this case is also determined based on a map showing the relationship between the reduction ratio (gear ratio) and the throttle opening as shown in FIG.

Further, the target deceleration force calculating means 9 in the ECU 98
8d is the shift lever position (D range, 2nd
The target deceleration force is calculated based on information such as the range and the vehicle speed (S206). As shown in FIG. 9, this target deceleration force is an ideal deceleration force that has a uniform deceleration change amount and does not make the vehicle occupant feel uncomfortable such as sudden deceleration. Then E
The MG drive / regenerative power calculation means 98c of the CU 98 calculates the drive amount of the MG 64 in the current vehicle state (S2).
07). That is, by driving the MG 64 as a motor or a generator, the load of the engine 60 is adjusted (engine friction adjustment) to control the amount of engine braking, and the deceleration force is corrected to an ideal value. In this case, the difference between the target deceleration force calculated in (S206) and the deceleration force due to the engine braking action is determined by MG64.
The hatched portion in FIG. 9 is the adjustable range by the MG 64. In the case of the second embodiment, since the calculation of the target throttle opening (boost control) is performed and the engine friction is adjusted in (S205), the deceleration force due to the engine braking action is equal to the engine friction after the boost control. Calculated based on gear ratio, vehicle speed, etc. At this time, if (target deceleration force)-(deceleration force due to engine braking action) is negative, MG 64 performs drive control, and if positive, regenerate control. Then, the calculated MG drive / regenerative power is output (S208), and the target throttle opening calculated in (S205) is output (S204).

Thus, the output of the target throttle opening degree,
That is, by performing the boost control and the MG drive / regenerative power output control, as shown in FIG. 9, the actual deceleration force can be made closer to the target deceleration force, and the vehicle occupant can smoothly feel uncomfortable. Slow deceleration can be reliably performed.

Embodiment 3 FIG. FIG. 10 shows, as Embodiment 3, a flowchart for explaining a control procedure when the MG 64 as an auxiliary machine is controlled when forced deceleration is performed by operating a brake pedal together with the engine brake. In the third embodiment, a vehicle equipped with a brake assist system, which has been increasingly mounted in recent years, that is, a system that can obtain a sufficient deceleration force even with a small depression operation of a brake pedal will be described as an example.
This system assists the stepping force by a servo mechanism that operates based on the difference between the negative pressure accumulated by the engine and the atmospheric pressure. Therefore, as shown in FIG. 11, the fluctuation of the deceleration force appears for the same brake depression amount when the boost negative pressure of the brake booster is high and when it is low. The driver is C
In addition to the fluctuation of the deceleration force caused by the shift of the VT 76 to the Lo side, the fluctuation of the deceleration force due to the negative pressure state of the brake booster gives a sense of incongruity. In the third embodiment,
This eliminates discomfort caused by a sudden change in engine braking action and a difference in deceleration force due to a difference in boost negative pressure. Note that the configuration of the ECU is the same as that of the ECU 98 in FIG. 8, except that the value of the boost negative pressure of the brake booster is input to the MG drive / regeneration force calculation means 98c, and the depression of the brake pedal is input to the target deceleration force calculation means 98d. The quantity is input, and necessary calculations are performed based on the information.

In the flowchart of FIG. 10, (S3
00) to (S305) correspond to (S10) in the first embodiment.
0) to (S105) and (S200) to (S
205), the description is omitted.

After calculating the target throttle opening in (S305), the ECU 98 calculates the target deceleration force based on the brake depression amount reflecting the driver's braking intention (S306). . Further, the MG drive / regeneration power calculating means 98c calculates the brake braking force based on the brake depression amount (brake depression allowance), the boost negative pressure, and the like (S307). Fig. 1 Brake braking force
1, it can be easily obtained from a predetermined relation map. Then, the MG drive / regenerative power calculation means 98c calculates the control amount of the MG 64 in the current vehicle state (S308). That is, the load of the engine 60 is adjusted (engine friction adjustment) by driving and regenerating the MG 64 as a motor or a generator.
To control the engine braking action. in this case,
A value obtained by subtracting the deceleration force by the engine braking action and the brake braking force (deceleration force) calculated in (S307) from the target deceleration force calculated in (S306) is an amount that can be adjusted by the drive control of the MG 64, and is an amount that can be adjusted in FIG. The portion indicated by hatching is the adjustable range of the MG 64. In the case of the third embodiment, since the calculation of the target throttle opening (boost control) is performed in (S305) to adjust the engine friction, the deceleration force due to the engine braking action is equal to the engine friction after the boost control. Calculated based on gear ratio, vehicle speed, etc. At this time, (target deceleration force)-
When (deceleration force due to engine braking action + brake braking force) is negative, MG 64 is in drive control, and when positive, regenerate control is in effect. Then, the calculated MG drive / regenerative power is output (S309), and the target throttle opening calculated in (S305) is output (S304).

As described above, the output of the target throttle opening,
That is, by performing the boost control and the MG drive / regenerative output control, as shown in FIG. 12, even when the driver operates the brake pedal and requests forcible deceleration,
While controlling the deceleration force by the engine brake action,
It is possible for the driver to correct the actual deceleration force to the desired target deceleration force by the amount of brake depression, and it is possible to reliably perform smooth deceleration without causing the driver to feel uncomfortable.

Embodiment 4 FIG. FIG. 13 shows an example in which control similar to that of the third embodiment described above is applied to a vehicle having a brake hydraulic pressure control system instead of a brake booster and having a brake assist system capable of arbitrarily adjusting a brake braking force. It is shown. The ECU is almost the same as the ECU 98 shown in FIG. Also,
In the flowchart of FIG. 13, (S400) to (S400)
406) correspond to (S300) to (S30) in FIG.
The description is omitted because it is the same as 6). When the target deceleration force is calculated in (S406), the MG drive / regenerative force calculation means 98c determines the target regenerative force (S40).
7). This target regenerative force is a decelerating force generated on the engine 60 side by a load generated by the regeneration of the MG 64,
Its size is determined according to the state of charge of the battery. Subsequently, the ECU 98 calculates the engine braking force (S408). The deceleration force due to the operation of the engine brake is calculated (boost control) of the target throttle opening in (S405) to adjust the engine friction. Therefore, the deceleration force due to the operation of the engine brake is reduced by the engine friction after the boost control. , Gear ratio,
Calculated based on vehicle speed and the like. Then, it is determined whether or not the sum of the deceleration force by the target regenerative force calculated in (S407) and the deceleration force by the engine brake is larger than the target deceleration force calculated in (S406) (S409).

If the sum of the deceleration forces is smaller than the target deceleration force, that is, if it is determined that the braking force by the operation of the hydraulic system is necessary to obtain the target deceleration, the brake braking force is calculated. (S410). This brake braking force is a value obtained by subtracting the target regenerative force in (S407) and the engine braking force in (S408) from the target deceleration force calculated in (S406). And the ECU 98
Outputs the control amount of the MG drive / regenerative force based on the target regenerative force and outputs the control amount of the brake braking force (S411). Further, the target throttle opening calculated in (S405) is output (S404).

On the other hand, if the ECU 98 determines in S409 that the sum of the deceleration forces is larger than the target deceleration force, the process proceeds to S40.
This is a case where an excessive deceleration force is generated because the target regenerative force set in 7) is too large, and the MG drive regenerative force is corrected (S412). In this case, the MG drive regenerative force can be obtained by subtracting the engine braking force calculated in (S408) from the target deceleration force calculated in (S406). In this case, since the deceleration force satisfies the target deceleration force, even if the driver depresses the brake pedal, the brake braking force by the implemented hydraulic system is set to “0” (S413), and the engine 60 including the regeneration of the MG 64 is performed. A deceleration force is generated only by the friction of After that, the process proceeds to (S411) and (S404) to output each control amount.

As described above, even in a vehicle having a brake system in which the deceleration force can be adjusted by the hydraulic system, the control of the MG 64 and the engine boost control are performed to control the engine brake and to control the brake pedal of the driver. It is possible to perform deceleration according to the amount of depression, and it is possible to perform deceleration without a feeling of strangeness without causing the vehicle occupants including the driver to feel a sudden change in the deceleration change amount. In addition, when the brake braking force is adjusted by the hydraulic system, the MG 64 can be actively used, which can contribute to an improvement in vehicle fuel efficiency.

In each of the above-described embodiments, an example has been described in which the boost control of the engine and the control of the auxiliary equipment (air conditioner, alternator, MG, etc.) are performed together. Can be controlled,
Similar effects can be obtained.

Further, when controlling the auxiliary equipment, which auxiliary equipment is to be controlled is optional, but it is possible to control the auxiliary equipment in a priority order in which efficient deceleration control can be performed. preferable. Note that the CVT cannot change the reduction ratio unless the drive wheels are rotating, so the reduction ratio is shifted to the maximum Lo side by the time the vehicle stops, regardless of the presence or absence of the fuel cut control. Since the vehicle shifts to the Lo side of the CVT at the time of deceleration to prepare for a restart, the same effect can be obtained for a CVT vehicle without a fuel cut device.

[0058]

According to the present invention, the engine friction can be positively adjusted even when the reduction ratio of the continuously variable transmission ratio, which affects the magnitude of the inertia deceleration force, increases with vehicle deceleration. It is possible to adjust the amount of change in the deceleration of the coasting deceleration force, and it is possible to perform a smooth deceleration without giving the vehicle occupant a feeling of strangeness. In addition, since it is possible to perform ideal deceleration by controlling the drive of the motor / generator, it is possible to perform smooth deceleration that does not give a further uncomfortable feeling to the vehicle occupant.

[Brief description of the drawings]

FIG. 1 is a conceptual configuration diagram illustrating a schematic configuration of a vehicle including a control device according to a first embodiment of the present invention.

FIG. 2 is a flowchart illustrating a control procedure when the vehicle according to the first embodiment of the present invention decelerates only by coasting deceleration.

FIG. 3 is a map diagram illustrating a relationship among a throttle opening, a load correction rate, and a gear ratio according to the first embodiment of the present invention.

FIG. 4 is a block diagram illustrating a configuration of a CPU according to the first embodiment of the present invention.

FIG. 5 is an explanatory diagram illustrating transition of a deceleration force and the like in the first embodiment of the present invention.

FIG. 6 is a conceptual configuration diagram illustrating a schematic configuration of a vehicle according to Embodiments 2 to 4 of the present invention.

FIG. 7 is a flowchart illustrating a control procedure when the vehicle according to the second embodiment of the present invention decelerates only by coasting deceleration.

FIG. 8 is a block diagram illustrating a configuration of a CPU according to a second embodiment of the present invention.

FIG. 9 is an explanatory diagram illustrating a transition of a deceleration force and the like in a second embodiment of the present invention.

FIG. 10 is a flowchart illustrating a control procedure when a vehicle according to a third embodiment of the present invention decelerates.

FIG. 11 is an explanatory diagram illustrating a relationship between a deceleration force and a brake depression amount according to a third embodiment of the present invention.

FIG. 12 is an explanatory diagram illustrating transition of a deceleration force and the like according to a third embodiment of the present invention.

FIG. 13 is a flowchart illustrating a control procedure when the vehicle according to the fourth embodiment of the present invention decelerates.

[Explanation of symbols]

10 engine, 12 continuously variable transmission (CVT), 30
ECU, 40 throttle actuator, 50 fuel cut device, 52 air conditioner.

──────────────────────────────────────────────────続 き Continued on the front page (51) Int.Cl. ⁷ Identification symbol FI theme coat ゛ (Reference) F02D 29/00 F02D 29/02 D 5H115 29/02 341 341 29/04 B 29/04 29/06 E 29 / 06 41/12 310 41/12 310 330L 330 F16H 61/04 F16H 61/04 B60K 9/00 C (72) Inventor Yasushi Ito 1 Toyota Town, Toyota City, Aichi Prefecture Toyota Motor Corporation F-term (reference ) 3D041 AA33 AB01 AC09 AC20 AD00 AD04 AD09 AD10 AD18 AD37 AD51 AD52 AE00 AE04 AE08 AE31 AF01 3G065 AA11 CA13 DA04 EA05 FA05 FA12 GA11 GA28 GA29 GA31 GA36 GA37 GA43 3G093 AA06 AA12 CB07 DA01 DB10 EB07 DB08 EB03 EB09 EC02 FA10 FA11 FB02 FB05 3G301 HA01 JA04 KA16 KA26 LA03 LA04 LC03 MA24 NA08 NC04 ND02 PA11A PA11Z PA14Z PE01Z PF02Z PF03Z PF05Z P F08Z PF12Z PF13Z 3J052 AA04 AA11 CA21 EA04 EA06 FB33 GC13 GC23 GC35 GC36 GC46 GC72 HA11 LA01 5H115 PA01 PC06 PG04 PI24 PI29 PU09 PU25 PU29 PV09 QE10 QI04 QI07 QI09 QI15 QN03 RB08 SE23 TO08

Claims (3)

[Claims] 1. A traveling control device for a vehicle, comprising: an engine; and a continuously variable transmission disposed between the engine and driving wheels and capable of continuously changing a gear ratio. In a case where the engine is driven by the drive wheels while increasing to obtain the coasting deceleration force of the vehicle, the vehicle has an adjusting means for adjusting the engine friction so that the deceleration change amount of the vehicle is within a predetermined value. Control device of the vehicle to be driven. 2. A traveling control device for a vehicle, comprising: an engine; and a continuously variable transmission disposed between the engine and driving wheels and capable of continuously changing a gear ratio. When obtaining the coasting deceleration force by driving the engine by the drive wheels while increasing and the forced deceleration force by the brake operation of the vehicle driver, the engine friction is adjusted so that the deceleration change amount of the entire vehicle is within a predetermined value. A travel control device for a vehicle, comprising: an adjusting unit configured to perform the adjustment. 3. The control device according to claim 1, wherein the adjustment unit adjusts engine friction by performing at least one of boost pressure control of the engine and drive control of auxiliary equipment. Vehicle travel control device.