JP3528431B2 - Automatic traveling control device - Google Patents

Description

Detailed Description of the Invention

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an automatic cruise control device,
In particular, the present invention relates to an automatic travel control device that controls a drive source and an automatic transmission so as to adjust a vehicle speed according to a predetermined condition.

[0002]

2. Description of the Related Art Conventionally, it has been required to reduce a driver's burden by manually performing a manual operation by a driver by a control device. An automatic traveling control device is one that meets such a demand. There is. As an automatic traveling control device, a device that performs constant speed traveling control is most commonly put into practical use, and this device is based on the vehicle speed difference between the target vehicle speed and the detected actual vehicle speed. Let the car run.

Recently, an automatic traveling control device for performing follow-up traveling control has been partially put into practical use, and this device is based on the actual inter-vehicle distance from a forward traveling vehicle detected by a laser radar device or the like. The vehicle is made to travel at a predetermined inter-vehicle distance so as to follow the vehicle traveling ahead. In the following, the forward traveling vehicle that is the target of the follow-up traveling control is referred to as a target vehicle.

Further, an automatic traveling control device having both control functions of constant speed traveling control and following traveling control has been put into practical use.
This device performs constant-speed traveling control while the target vehicle is not detected, performs follow-up traveling control when the target vehicle is detected, and performs constant-speed traveling control again when the target vehicle disappears.

For example, in the case of an engine vehicle, a conventional automatic cruise control apparatus is an electronic engine control unit (E-ECU),
It has an electronic control unit (T-ECU) for an automatic transmission and a cruise computer. The cruise computer judges the necessity of acceleration / deceleration based on the detected values of the vehicle speed and the inter-vehicle distance, and outputs a control signal corresponding to this judgment to the E-ECU and the T-ECU. The E-ECU adjusts the engine output by opening and closing the throttle of the engine according to the instruction from the cruise computer. The T-ECU also controls the automatic transmission according to the instructions from the cruise computer. In this way, the vehicle speed is adjusted and constant-speed traveling or follow-up traveling is performed.

[0006] Further, as an automatic traveling control device proposed hitherto, Japanese Patent Laid-Open Nos. 4-208647 and 6-
There is one disclosed in Japanese Patent No. 111200, in which the former describes a constant speed traveling control device that maintains a target vehicle speed, and the latter describes an inter-vehicle distance control device that downshifts depending on the situation.

FIG. 13 shows various standard settings for control in the conventional apparatus. The figure (a) is E-EC
The throttle opening characteristic is set to U. The horizontal axis represents time and the vertical axis represents throttle opening, indicating the opening speed and size of the throttle. The figure actually shows changes in the opening of the throttle for several seconds. The E-ECU is
An actuator for opening / closing the throttle is controlled so that the throttle opens according to the throttle opening characteristic. The engine output increases as the throttle opens.

FIG. 2B shows a gear shift pattern set in the T-ECU. The vehicle speed is plotted on the horizontal axis and the throttle opening is plotted on the vertical axis. ing. When the actual vehicle speed reaches the set vehicle speed on the shift pattern, the T-ECU controls the automatic transmission to perform the corresponding shift. Although FIG. 11B shows only the shift pattern at the time of the downshift, the same shift pattern is set for the upshift.

Further, the lock-up control area is shown by hatching in FIG. The lockup control is control for engaging a lockup clutch provided in parallel with the torque converter, as shown in FIG. 13 (c). By this control, the transmission rate of the output torque from the engine to the automatic transmission becomes higher than that through the torque converter, so that the fuel efficiency is improved.

In the lockup control, the slip ratio of the lockup clutch (hereinafter simply referred to as the slip ratio) is 0 to 0.
The operation is performed within the range of 100%, the lock-up state is set at the slip rate of 0%, the non-lock-up state is set at the slip rate of 100% (lock-up control is not performed), and the lock-up slip state is established between the two. As indicated by the diagonal lines in FIG. 6B, in the reference setting, the lockup control region is set in a part of the fifth speed, which is the highest speed gear stage, and the region L in the diagram is set.
U51 is a slip ratio of 0%, and the low speed region LU52 is a region where the slip ratio is 0 to 100%. Further, the lockup control is not performed in the first speed to the fourth speed, and the lockup slip ratio is always 100%. Therefore, during the fifth speed running, the output torque transmission rate is increased by the lockup control, and the fuel efficiency is improved.

Further, FIG. 13 (d) shows an engine brake operating mode set in the T-ECU for constant speed traveling control, and shows whether or not the engine brake is applied at each gear. Generally, the standard setting of the automatic cruise control is generally the same as the D range when the automatic cruise control is not set. FIG. 11D is also a typical setting for the normal D range, in which engine braking is effective in the fourth and fifth speeds, and engine braking is not effective in the first to third speeds. Then, the T-ECU controls the automatic transmission according to this setting.

[0012]

The conventional automatic cruise control apparatus controls the engine and the automatic transmission according to the standard setting as described in FIG. This reference setting is suitably determined for the most commonly used apparatus for constant speed traveling control, that is, for the control that does not result in significant acceleration / deceleration.

On the other hand, when the follow-up running control is performed, the running of the vehicle speed must be varied, and a large deceleration is required when the target vehicle decelerates and approaches rapidly. Further, when the target vehicle disappears and the vehicle is switched to the constant speed traveling control after deceleration by the following traveling control, a large acceleration is required to reach the target vehicle speed.

However, conventional control based only on standard setting cannot cope with such a change in the degree of acceleration / deceleration demand.
I was able to obtain only constant acceleration and deceleration. Therefore, there is a possibility that the deceleration force will be insufficient in the situation where a large deceleration is required as described above, and the acceleration force may be insufficient in the situation that a large acceleration is required, and the driver may feel a sense of rattling. was there.

Furthermore, in the control based only on the reference setting, the throttle opening characteristic is constant regardless of the gear position at the start of acceleration in a situation in which the target vehicle disappears from the following running and acceleration to the target vehicle speed is started. Therefore, only the output torque corresponding to the throttle opening characteristic was obtained. Therefore, the torque may be insufficient if the gear is shifted to the high speed gear stage at the start of acceleration, and the torque may be excessive if the gear is shifted to the low speed gear stage, and the driver may not obtain a good acceleration feeling.

SUMMARY OF THE INVENTION It is an object of the present invention to solve the above problems and to provide an automatic cruise control device capable of controlling as follows by adjusting a reference setting for automatic cruise control: (1) When the target vehicle is decelerating, the deceleration performance can be improved according to the degree of deceleration demand. (2) The target vehicle speed is reached by constant speed traveling control after deceleration by the follow-up traveling control. Therefore, it is possible to improve the acceleration performance when accelerating. (3) It is possible to improve the acceleration feeling when accelerating to reach the target vehicle speed with constant-speed traveling control after decelerating with follow-up traveling control. it can.

Although the case of the engine vehicle has been described above, the same applies to the case where the automatic cruise control device is applied to an electric vehicle having a motor as a drive source or a hybrid vehicle having a motor and an engine. is there.

[0018]

SUMMARY OF THE INVENTION The present invention controls a vehicle that follows a vehicle traveling in front by controlling a vehicle speed by controlling a vehicle drive source and an automatic transmission connected to the vehicle drive source via a torque converter. The lockup adjusting means for adjusting the lockup slip ratio of the torque converter, wherein the lockup adjusting means follows the vehicle traveling in front by using the braking force of the drive source. When deceleration is performed in the gear stage for
The lockup slip ratio is changed according to the deceleration demand and according to the gear .

Here, the "driving source" is for generating the driving force of the vehicle, and is, for example, an engine or a motor as a prime mover, or both of them (hybrid) may be used. The "brake force of the drive source" is, for example, a rotational resistance force (engine braking force) generated by the engine against input rotation from the transmission side, and a brake based on a regenerative torque during regenerative braking of the motor, for example. Power.

The lock-up slip ratio is defined for each gear, for example, and is defined corresponding to the vehicle speed and the drive speed of the drive source. “Change of lock-up slip ratio” includes, for example, (1) 100% → 0% (release → engagement),
(2) 100% → 0 to 100% (release → slip),
(3) 0 to 100% → 0% (slip → engagement), (4)
The four modes of large → small in the range of 0 to 100% (slip) are included. The lock-up slip ratio is set, for example, according to the gear and the vehicle speed. Particularly, the modes (1) and (2) show that the lockup control is performed at the gear and the vehicle speed at which the lockup control was not performed before the adjustment.

The "deceleration demand" means the degree to which deceleration is requested, for example, "the difference between the target deceleration and the actual deceleration".
It can be expressed by "the reduction rate of the inter-vehicle distance" or the like.

In the above structure, when the braking force of the drive source is used to decelerate to follow the vehicle traveling in front, the lock-up slip ratio is changed according to the deceleration demand, so the drive source automatically The transmission rate of the rotational resistance force to the transmission can be increased to increase the deceleration.

Further, with the shift pattern adjustment means for adjusting the shift pattern when the shift takes place in front Symbol automatic transmission,
Speed change pattern adjustment means, after the deceleration to follow the front vehicle traveling in the following distance control is performed, when the acceleration for reaching the target vehicle speed at a constant speed running control is performed, acceleration and It is adjusted the shift pattern as easily
Good .

According to the above configuration, when the follow-up running control decelerates to follow the vehicle traveling ahead, and the constant-speed running control accelerates to reach the target vehicle speed,
The shift pattern is adjusted to facilitate acceleration. "Adjusting the shift pattern so that it is easy to accelerate" means, for example, increasing the vehicle speed or the drive source speed for shifting,
By holding the gear (regulating the shift), the vehicle runs without shifting up to a high speed to shorten the time required for acceleration. This adjustment may be performed according to the acceleration demand. The acceleration demand can be represented by, for example, a vehicle speed difference between the target vehicle speed and the actual vehicle speed or a drive speed difference of the drive source corresponding thereto.

Further, after the deceleration to follow the forward vehicle traveling in front Symbol following cruise control is performed, when the acceleration for reaching the target vehicle speed at a constant speed running control is performed, the acceleration at the start The output torque of the drive source may be adjusted according to the speed reduction ratio of the automatic transmission in.

According to the above configuration, when the follow-up running control decelerates to follow the vehicle traveling ahead, and the constant-speed running control accelerates to reach the target vehicle speed,
The output torque of the drive source is adjusted according to the speed reduction ratio of the automatic transmission at the start of acceleration. Therefore, even when the operating gear stage at the start of acceleration is the high gear stage and the reduction ratio is small, it is possible to perform acceleration at the required acceleration by adjusting the output torque. The output torque can be adjusted, for example, by controlling the throttle opening degree for the engine and by controlling the switching operation of the inverter for the motor.

[0027]

BEST MODE FOR CARRYING OUT THE INVENTION An automatic cruise control device according to an embodiment of the present invention will be described below with reference to the drawings. Hereinafter, a mode in which the present invention is applied to a vehicle equipped with an engine as a drive source will be described.

[Embodiment 1] FIG. 1 is a block diagram showing the configuration of a vehicle drive system controller including an automatic cruise controller according to this embodiment. This automatic cruise control device is E-
ECU3, T-ECU5 and cruise computer 7
Among these, the E-ECU 3 and the T-ECU 5 also function as a control device for normal traveling.

The E-ECU 3 controls the throttle opening, the ignition timing and the fuel injection amount of the engine E on the basis of the input information such as the engine speed, the accelerator operation, the brake operation and the vehicle speed to output the engine E. Is being adjusted. Here, regarding the throttle opening, a control value of the throttle opening is determined based on the input information, and a signal corresponding to this control value is output to drive the throttle actuator 101. As a result, the electronic throttle 105 provided in the intake conduit 103 of the engine E is opened / closed, and the throttle opening becomes a value corresponding to the control value determined by the E-ECU 3.

The T-ECU 5 controls the automatic transmission A based on input information such as the shift position and the vehicle speed. The automatic transmission A includes a torque converter with a lock-up clutch, a five-speed transmission mechanism including a planetary gear mechanism having a plurality of friction engagement devices (clutch and brake),
And a hydraulic control device having a plurality of solenoid valves. Then, the T-ECU 5 drives the solenoid valve of the hydraulic control device to engage / disengage each friction engagement device to change gears, and activates / deactivates the engine brake at each gear. Further, the solenoid valve of the hydraulic control device is driven to control the slip ratio of the lockup clutch to perform lockup control.

Next, the cruise computer 7 will be described. The target vehicle speed Vt and the target inter-vehicle time Tt are input to the cruise computer 7 by the driver's setting operation. The target vehicle speed Vt is a target value of the vehicle speed during constant speed travel control. Further, the target inter-vehicle time Tt is a target value (for example, 2 seconds) of the time required for the host vehicle to travel the inter-vehicle distance from the target vehicle during the follow-up travel control. (Note that the inter-vehicle distance target value itself may be input instead of the target inter-vehicle time Tt.) Furthermore, the cruise computer 7 detects a vehicle speed from a vehicle speed sensor 9 attached to the automatic transmission A (hereinafter, referred to as a vehicle speed detection value). , The actual vehicle speed Vr) is input, and the detected value of the inter-vehicle distance to the target vehicle is detected by the laser radar 11 provided as the inter-vehicle distance detecting device at the front of the vehicle (hereinafter,
The actual inter-vehicle distance Dr) is input.

The cruise computer 7 judges the necessity of acceleration / deceleration on the basis of these input information, and outputs a control signal corresponding to this judgment to the E-ECU 3 and the T-ECU 5. Then, the engine E and the automatic transmission A are controlled in accordance with the control signal, and as a result, the vehicle speed is increased or decreased to achieve the target vehicle speed Vt and the target inter-vehicle time Tt.

As a general outline of the automatic traveling control, the constant speed traveling control is performed when the laser radar 11 cannot detect a vehicle traveling ahead within a predetermined distance. Here, based on the difference between the target vehicle speed Vt and the actual vehicle speed Vr, control is performed to accelerate when the actual vehicle speed Vr becomes low, and control is performed to decelerate when the actual vehicle speed Vr becomes high. In this way, steady running at the target vehicle speed Vt is performed.

When the forward traveling vehicle is detected within the predetermined distance by the laser radar 11, the following traveling control is performed with the forward traveling vehicle as the target vehicle. Here, control is performed to obtain a required inter-vehicle distance (hereinafter referred to as a required inter-vehicle distance Dx) from the product of the target inter-vehicle time Tt and the actual vehicle speed Vr, and adjust the vehicle speed so that the required inter-vehicle distance Dx and the actual inter-vehicle distance Dr become equal. Done. As a result, the vehicle travels following the target vehicle after the target inter-vehicle time Tt.

When the vehicle speed of the target vehicle (which can be calculated from the actual inter-vehicle distance Dr and the actual vehicle speed Vr of the host vehicle) is higher than the target vehicle speed Vt for constant speed traveling control, the follow-up traveling control is not performed. In such a situation, by performing the constant speed traveling control, the inter-vehicle distance from the target vehicle is increased, and the target vehicle is lost later.

Next, the control characteristic of this automatic running control device will be described with reference to the flowchart of FIG. In this device, the setting of the engine brake operating mode, the shift pattern, the lock-up control, and the throttle opening characteristic is changed based on the target vehicle speed Vt, the target inter-vehicle time Tt, the actual vehicle speed Vr, and the actual inter-vehicle distance Dr as follows. . Then, the engine E and the automatic transmission A are controlled with the changed settings.

In FIG. 2, when starting (S1
0), signal input processing is performed (S20), and it is determined whether or not the automatic travel control is being performed by turning on / off the set switch for the automatic travel control (S30). When the automatic travel control is not being performed, the process returns (S130), and when the automatic travel control is being performed, the process proceeds to step S40. In step S40, it is determined whether or not the target vehicle is approaching from the front and is decelerating based on the actual inter-vehicle distance Dr detected by the laser radar 11. The result of step S40 is YES, for example, when the target vehicle is decelerating, or when another vehicle interrupts the preceding vehicle. If YES in step S40, the settings of the control of the engine E and the automatic transmission A are changed in steps S50 to S60, and the process returns (S130).

[Step S50] Setting Change by Engine Brake Operation Mode Switching Means As shown in FIG. 3, in the standard setting, engine braking is activated at the 4th and 5th speeds, but here, at the 2nd to 5th speeds. T-E so that the engine brake works at the gear
Change the setting of CU5. The T-ECU 5 operates according to this setting, and controls the automatic transmission A so that the engine brake is applied at the third speed when downshifting from the fourth speed to the third speed, for example.

In this embodiment, since the first speed is not used during automatic travel control, setting switching for operating the engine brake is not performed for the first speed.
In addition, before the automatic travel control is set, a sports mode (a mode in which the driver manually selects a gear stage and the engine brake is operated at each gear stage, for example, Japanese Patent Laid-Open No. 5-3324).
No. 43) has been set, the mode has been switched to a mode for operating the engine brake in advance.

Further, a transmission mechanism and a control device, which correspond to the above-mentioned switching of the engine brake operation mode and which makes or does not make the engine brake effective in each gear, are disclosed in the above-mentioned JP-A-5-332443. JP-A-6-341522 and JP-A-6-341522, which are well known and will not be described.

[Step S55] Change of setting of downshift vehicle speed by shift pattern adjusting means The required inter-vehicle distance Dx is obtained from the target inter-vehicle time Tt and the actual vehicle speed Vr, and the target deceleration Gt is calculated based on the required inter-vehicle distance Dx and the actual inter-vehicle distance Dr. Ask for. The target deceleration Gt is set in advance on the map, and in consideration of the degree of demand for deceleration, the larger the difference between the required inter-vehicle distance Dx and the actual inter-vehicle distance Dr, the larger the target deceleration Gt is set. On the other hand, the actual deceleration (actual deceleration) G is calculated based on the actual vehicle speed Vr. Then, as shown in FIG. 4, the shift pattern is adjusted so that the downshift vehicle speed increases as the difference between the target deceleration Gt and the actual deceleration G increases. This adjustment is optimized for each gear. With such an adjustment, when the degree of demand for deceleration is high, the engine brake of the low-speed gear is used earlier, so the deceleration time until the target inter-vehicle time Tt is achieved becomes shorter.

[Modification 1 of Step S55] The inter-vehicle distance reduction amount per unit time (hereinafter referred to as inter-vehicle distance reduction rate) is calculated from the temporal change of the actual inter-vehicle distance Dr. And
As shown in FIG. 5, the shift pattern is adjusted so that the downshift vehicle speed becomes higher as the inter-vehicle distance reduction rate becomes larger. This adjustment is also optimized for each gear. Here, it is determined that there is a high demand for deceleration when the target vehicle is approaching rapidly.

[Modification 2 of Step S55] Actual Vehicle Speed Vr
Based on the detected value of the actual vehicle-to-vehicle distance Dr, the target value G ′ of the rate of change of deceleration per unit time is obtained. The target value G'of the deceleration change rate is set in advance on the map, and the higher the actual vehicle speed Vr and the greater the actual inter-vehicle distance Dr, the greater the deceleration change rate. The target value G'is set to be large. Then, as shown in FIG. 6, the shift pattern is adjusted so that the downshift vehicle speed becomes higher as the target value G ′ of the deceleration change rate becomes larger. This adjustment is also optimized for each gear. Here, it is determined that the degree of demand for deceleration is high when the target value G ′ of the deceleration change rate is large.

[Step S60] In the lockup slip ratio setting change reference setting by the lockup adjusting means, the lockup control is performed only in the fifth speed as described above. This is because lockup control is performed to increase the engine torque transmissibility for the purpose of improving fuel efficiency at the fifth gear, which is the highest gear.

Here, the lockup control is used for the purpose of improving the deceleration in the automatic traveling control. That is, when the engine brake is operated, the engine is reversely driven by the rotational force on the wheel side, and the rotational resistance force of the engine is transmitted to the automatic transmission, whereby deceleration is performed.
Conventionally, the rotational resistance of the engine is limited to the torque converter T
Was transmitted through. In the present embodiment, the rotation resistance force is transmitted through the lockup clutch to improve the transmission rate of the rotation resistance force. Therefore, the engine braking is more effective and the deceleration is increased.

Specifically, the setting of the lockup control area is changed as shown by the diagonal lines on the shift pattern of FIG.
In the figure, the setting of the lockup control for the fifth speed (areas LU51, LU52) is the same as the reference setting described in FIG. Further, areas LU4 and LU3 for newly performing lockup control are set in the entire vehicle speed range of the fourth speed and the partial vehicle speed range of the third speed. This area LU
4. In LU3, the slip ratio is set to a predetermined value between 0 and 100%, and when the gear stage, vehicle speed, and throttle opening are in this range, control to bring the lockup slip state at the slip ratio is performed. Done.

In step S60, the lockup slip ratio is further adjusted as shown in FIG. The figure illustrates the fourth speed, and the target deceleration G
The difference between t and the actual deceleration G is calculated, and the lockup slip ratio is reduced as the difference is increased. At the same time, the lockup slip ratio is reduced as the vehicle speed increases. (Vehicle speeds v1 to v3 in the figure correspond to vehicle speeds v1 to v3 in FIG. 7.) The fourth speed has been described here, but the same applies to other gears. By this adjustment, when the demand for deceleration is high, the engine braking is strongly applied to increase the deceleration, and the deceleration time until the target inter-vehicle time Tt is achieved is shortened.

[Modification of Step S60] As shown in FIG. 9, the lock-up slip ratio is decreased as the inter-vehicle distance decrease ratio is larger, and the adjustment according to the vehicle speed is performed similarly to FIG. As shown in 9, adjust according to the gear stage. Here, it is determined that the demand for deceleration is higher as the target vehicle is more rapidly approaching.

The case where step S40 is YES (the target vehicle is approaching and decelerating) has been described above. Next, a case where step S40 is NO will be described. If step S40 is NO, it is determined whether or not the target vehicle has been lost (S70), and if not, the process returns (S130). YE in step S70
The S occurs when the target vehicle accelerates and is separated by a predetermined distance or longer, or when the lane is not changed. When the target vehicle is lost, the follow-up traveling control is ended and switching to the constant speed traveling control is performed. Here, at the end of the following travel control, the actual vehicle speed V is higher than the target vehicle speed Vt.
r is decreasing. Then, according to the decrease of the actual vehicle speed Vr,
In addition, a downshift is performed during the follow-up traveling control in response to a deceleration request, and the vehicle is traveling at a low speed gear. In such a situation, along with the loss of the target vehicle, in the flowchart of FIG. 5, the setting change for the control of the engine E and the automatic transmission A as described below is performed in steps S80 to S120, and the process returns (S130). ).

If YES in step S70, the vehicle speed difference between the target vehicle speed Vt and the actual vehicle speed Vr is calculated (S80), and a large acceleration is required by comparing the vehicle speed difference with a predetermined value. It is determined (S90). Large acceleration is required if the vehicle speed difference is larger than the above specified value (YES)
Is judged. Then, in order to smoothly perform this large acceleration in a short time, the setting is changed in the following steps S100 and S110, and the process returns (S130).

[Step S100] Change of setting of shift vehicle speed by shift pattern adjusting means FIG. 10 shows the adjustment contents of step S100, and illustrates the shift vehicle speed from the third speed to the fourth speed. In the figure,
The shift pattern of the standard setting is shown by the solid line. On the other hand, in step 100, the transmission vehicle speed is set to the high speed side, as indicated by the dotted line and the alternate long and short dash line. Then, the larger the difference in vehicle speed between the target vehicle speed Vt and the actual vehicle speed Vr, the larger the change range of the transmission vehicle speed is set.

By the above adjustment, the shift pattern becomes easy to accelerate such that the shift is delayed and the vehicle is pulled up to a high vehicle speed. As a result, the acceleration performance is improved and the time required to reach the target vehicle speed Vt is shortened. The adjustment range of the shift vehicle speed is set in consideration of the fact that the greater the vehicle speed difference between the target vehicle speed Vt and the actual vehicle speed Vr, the higher the demand for acceleration.

Incidentally, in step S100, it goes without saying that the shift patterns for shifts of other gears not shown in FIG. 10 are adjusted in the same manner. Then, the shift pattern for the downshift is also changed to the high vehicle speed side. Therefore, for example, when the vehicle is traveling at the fifth speed and the downshift vehicle speed is changed to the high vehicle speed side when switching to the constant speed traveling control, the downshift may be performed together with this switching.

Further, in the above, the case where the setting of the shift vehicle speed is changed has been described, but as a modified example of this configuration, it may be set so that the gear stage is held during acceleration.

[Step S110] Setting Change by Throttle Opening Characteristic Adjusting Unit As shown in FIG. 11, the setting of the throttle opening characteristic is changed according to the operating gear. This operating gear is specified in step S100. Adjust the throttle so that the higher the gear, the faster the throttle will open. According to this adjustment, the output torque rises after the start of acceleration at a higher speed for higher gears. On the other hand, the gear ratio of the automatic transmission A is smaller at higher gears. Therefore, by changing the setting of this step, the driving torque of the wheels can be made uniform irrespective of the operating gear stage, and even when accelerating at a high speed gear stage, the feeling of rattling at the time of acceleration is eliminated. As described above, in FIG. 11, the throttle opening characteristic is adjusted so that the optimum acceleration feeling is obtained at each gear.

Further, in step S110, as shown in FIG. 11, even if the gear position is the same, the target vehicle speed V
As the vehicle speed difference between t and the actual vehicle speed Vr is larger, the throttle opening characteristic is adjusted so that the throttle opens faster. Here, it is determined that the greater the vehicle speed difference, the higher the degree of demand for acceleration, and the acceleration performance is improved.

The above is the control when step S90 is YES (large acceleration is required). On the other hand, if NO in step S90 (no need for large acceleration), the throttle opening characteristic is adjusted according to the current gear as in step S110 (S120), and the process returns (S13).
0). Here, since a large acceleration is not necessary, the shift pattern is not adjusted, but the acceleration feeling is improved by adjusting the throttle opening characteristic.

In the automatic running control system of the present embodiment described above, when the target vehicle is approaching and decelerating, the engine braking operation mode, the shift pattern and the lock-up slip ratio are set in step S5.
By performing the changes described in 0 to S60, it is possible to increase the deceleration and shorten the deceleration time until reaching the required vehicle speed. In particular, in consideration of the deceleration demand, the higher the demand is, the larger the range of change of each setting described above, so that the deceleration can be optimized.

Further, in this embodiment, when the target vehicle is lost and the following traveling control is switched to the constant speed traveling control, as described in steps S100 to S120,
Adjust the shift pattern settings and the throttle opening characteristics settings to facilitate acceleration. As a result, the acceleration time to reach the target vehicle speed can be shortened and the acceleration feeling can be improved. In particular, the degree of change in each setting is increased as the demand is higher, in consideration of the demand for acceleration, so that the acceleration time and the feeling of acceleration can be optimized.

In the above embodiment, the automatic running control device provided in the engine-equipped vehicle has been described.
On the other hand, the automatic cruise control device of the present invention can be similarly applied to an electric vehicle equipped with a motor as a drive source and a hybrid vehicle equipped with an engine and a motor. In this case, instead of the throttle opening in the case of engine control, the current supplied to the motor may be controlled. This modification corresponds to the second embodiment described below.
It is possible in the same way.

[Second Embodiment] The second embodiment differs from the above-described first embodiment only in the configuration when the determination in step S40 shown in FIG. 2 is YES. In the present embodiment, the degree of demand for deceleration is taken into consideration, and it is selected whether to perform deceleration by performing a downshift or by performing lockup control.

As described in the first embodiment, the deceleration can be increased by both downshift and lockup control. However, the lockup control does not increase the deceleration too much, so
The deceleration can be increased more by performing the downshift and decelerating than by the deceleration by the lockup control. On the other hand, when downshifting is performed, a shift shock occurs, and the downshift time (the time until the downshift is completed, which is determined by the responsiveness of the automatic transmission) causes a feeling of fancy. Therefore, if the lock-up control can meet the demand for deceleration, it is desirable not to intentionally perform the downshift. From such a point of view, the second embodiment optimizes the deceleration control when the target vehicle is approaching.

Further, when the downshift and the lockup control are selected as described above, it may not be possible to enter the lockup slip state due to the failure of the lockup clutch control or the occurrence of judder. In such a case, in the second embodiment, not the lockup control but the downshift is performed to decelerate.

FIG. 12 is a flow chart showing the control contents of the second embodiment, and only the difference from the flow chart of the first embodiment shown in FIG. 2 is shown. In FIG. 12, if YES in step S40, the target deceleration Gt is calculated as described in step S55 of the first embodiment, and the difference between the target deceleration Gt and the actual deceleration G is calculated (S42). This difference in deceleration is compared with the predetermined value Gα (S44). The predetermined value Gα is set to the maximum value of the deceleration that can be achieved by setting the lockup state or the lockup slip state in the current gear stage. If the deceleration difference (Gt-G) is greater than or equal to the predetermined value Gα in step S44, it is determined that the target deceleration Gt cannot be achieved by the lockup control, so downshift is executed (S46). . At this time, step S5 of the first embodiment
As described in 0, the engine brake operation mode is switched and the engine brake is controlled to be effective.

On the other hand, in step S44, the deceleration difference (Gt
-G) is smaller than the predetermined value Gα, step S52
Proceeding to step S3, it is determined whether lockup control is possible in the lockup slip state. If YES in step S52, the lockup control setting is changed as in the first embodiment (S60), and the process returns (S1).
30). If step S52 is NO, step S
A downshift is executed at 46.

In the second embodiment, the downshift is not performed when the target deceleration Gt can be achieved by the lockup control, so that it is possible to reduce the frequency of shift shock and fantasy that accompany the downshift. Further, when lockup control is impossible, a downshift is performed instead, so a stable and constant deceleration can be obtained.

[0067]

According to the present invention, the lockup slip ratio is changed according to the deceleration demand when the vehicle is decelerated to follow the vehicle traveling in front by utilizing the rotational resistance of the drive source. , It is possible to increase the transmission rate of the braking force from the drive source to the automatic transmission to increase the deceleration during follow-up travel control, and it is possible to meet this request even when a relatively large deceleration is required. It will be possible.

Further, according to the present invention, when deceleration for following the vehicle traveling ahead is performed by the follow-up traveling control, and then acceleration is performed to reach the target vehicle speed by the constant-speed traveling control, The shift pattern is adjusted to facilitate acceleration. Therefore, for example, when the vehicle speed difference between the target vehicle speed and the actual vehicle speed is large as the acceleration request degree, the gear speed is held up to a high speed by increasing the vehicle speed or the drive source speed at which the gear shift specified in the gear shift pattern is performed. As a result, control such as shortening the time required for acceleration becomes possible.

Further, according to the present invention, when the follow-up running control decelerates to follow the vehicle traveling ahead, the constant-speed running control accelerates to reach the target vehicle speed. The output torque of the drive source is adjusted according to the speed reduction ratio of the automatic transmission at the start. Therefore, even if the operating gear stage at the start of acceleration is the high gear stage and the reduction ratio is small, the output torque can be adjusted to accelerate at the required acceleration by adjusting the output torque. It is possible to give a sense of acceleration.

[Brief description of drawings]

FIG. 1 is a block diagram showing a configuration of a vehicle drive system control device including an automatic cruise control device according to a first embodiment of the present invention.

FIG. 2 is a flowchart showing the control contents of the automatic cruise control device of FIG.

FIG. 3 is an explanatory diagram showing the content of adjustment of an engine brake operation mode during deceleration in the automatic travel control device of FIG. 1.

FIG. 4 is an explanatory diagram showing the content of adjustment of downshift vehicle speed during deceleration in the automatic travel control system of FIG. 1.

5 is an explanatory diagram showing the content of adjustment of downshift vehicle speed during deceleration in the automatic travel control system of FIG. 1. FIG.

FIG. 6 is an explanatory diagram showing the content of adjustment of downshift vehicle speed during deceleration in the automatic travel control device of FIG. 1.

FIG. 7 is an explanatory diagram showing the setting change contents of lockup control during deceleration in the automatic travel control system of FIG.

FIG. 8 is an explanatory diagram showing the content of adjustment of the lockup slip ratio during deceleration in the automatic cruise control device of FIG. 1.

9 is an explanatory diagram showing the content of adjustment of the lockup slip ratio during deceleration in the automatic travel control device of FIG. 1. FIG.

10 is an explanatory diagram showing the contents of setting change of a shift pattern at the time of acceleration in the automatic travel control device of FIG.

FIG. 11 is an explanatory diagram showing the setting change contents of the throttle opening characteristic at the time of acceleration in the automatic travel control device of FIG. 1.

FIG. 12 is a flowchart showing the control contents of the automatic travel control device of the second embodiment of the present invention.

FIG. 13 is an explanatory diagram showing reference settings for control in a conventional automatic cruise control device.

[Explanation of symbols]

3 E-ECU, 5 T-ECU, 7 cruise computer, 9 vehicle speed sensor, 11 laser radar.

─────────────────────────────────────────────────── ─── Continuation of front page (72) Inventor Kagenori Fukumura 1 Toyota-cho, Toyota-shi, Aichi Prefecture Toyota Motor Co., Ltd. (72) Inventor Yasaya Nakamura 1-cho, Toyota-shi, Aichi Toyota Motor Co., Ltd. (56) Reference JP-A-2-278069 (JP, A) JP-A-9-292019 (JP, A) JP-A-5-96978 (JP, A) JP-A-6-87356 (JP, A) JP-A-7-293289 (JP, A) JP-A-63-186059 (JP, A) JP-A-3-204456 (JP, A) JP-A-6-34025 (JP, A) JP-A-4-64768 (JP, A) JP-A-6-337064 (JP, A) (58) Fields investigated (Int.Cl. ⁷ , DB name) F02D 29/00 B60K 31/00 B60K 41/00 F16H

Claims (5)

(57) [Claims] 1. An automatic travel control device for controlling follow-up running to a vehicle traveling ahead by controlling a vehicle speed by controlling a drive source and an automatic transmission connected to the drive source via a torque converter. A lock-up adjusting means for adjusting the lock-up slip ratio of the torque converter, the lock-up adjusting means being provided in a gear stage for following the vehicle traveling in front by utilizing the braking force of the drive source. /> When deceleration is performed, the gears are responsive to the deceleration demand and
An automatic cruise control device characterized in that the lock-up slip ratio is changed according to a step . 2. The device according to claim 1, further comprising a shift pattern adjusting means for adjusting a shift pattern in which a shift is performed by the automatic transmission , wherein the shift pattern adjusting means is configured to perform the following traveling control. after deceleration to follow the front running vehicle is performed, when the acceleration for reaching the target vehicle speed at a constant speed running control is performed, and characterized by adjusting the shift pattern for easy acceleration Automatic driving control device. 3. A device according to claim 1, further after the deceleration to follow the front vehicle traveling in the following distance control is performed, the acceleration to reach the target vehicle speed at a constant speed running control When performing the above, the automatic travel control device comprising means for adjusting the output torque of the drive source according to the speed reduction ratio of the automatic transmission at the start of acceleration. 4. The device according to claim 1, wherein the gear stage is a gear to which a braking force of the driving force acts.
Specially obtained by downshifting
Automatic driving control device to be a feature. 5. The device according to claim 1, wherein the lock-up adjusting means responds to the same deceleration request degree.
The higher the gear, the more the lock-up slip
An automatic cruise control device characterized by reducing the rate.