JP2590590B2 - Constant speed traveling equipment for vehicles - Google Patents

Description

Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a constant speed traveling apparatus for a vehicle for automatically driving an automobile while maintaining the vehicle at a desired target speed.

(Conventional technology) This kind of constant speed traveling device is applied to a vehicle equipped with an automatic transmission. More specifically, when the vehicle is traveling at the highest speed of overdrive, its target vehicle speed is When the constant speed driving control is started, the throttle opening of the throttle valve is controlled to match the actual vehicle speed with the target vehicle speed. At this time, the throttle valve is controlled according to the actual vehicle speed and the magnitude of the throttle opening. Thus, the shift operation in the automatic transmission is performed. Here, the shift-down and shift-up operations of the automatic transmission are performed based on a shift-down line and a shift-up line of a shift map set in advance according to the vehicle speed and the throttle opening.

That is, when the vehicle is traveling uphill during constant speed running in overdrive, the actual vehicle speed decreases from the target vehicle speed. At this time, the throttle opening is increased to increase the actual vehicle speed. If the automatic transmission is widely opened beyond the downshift line, the automatic transmission is operated to downshift from the overdrive speed. Such a downshift
Acceleration of the vehicle is accelerated, so that the actual vehicle speed quickly returns to the target vehicle speed.

(Problems to be Solved by the Invention) By the way, during traveling at a constant speed in overdrive, when the vehicle travels on an uphill as described above, depending on the degree of the gradient on the uphill and the target vehicle speed, automatic shifting is performed. When the actual vehicle speed returns to the target vehicle speed after the downshift is performed by the engine, the load on the engine is greatly reduced, and accordingly, the throttle opening is also greatly reduced.
In such a case, if the throttle opening is reduced so as to cross the upshift line, the automatic transmission will
Conversely, the gear is shifted up to the overdrive speed. Here, assuming that the uphill that causes the above-described shift operation is still continuing, in the automatic transmission,
Shifting down from overdrive and upshifting to overdrive will be repeatedly performed,
Hunting may occur in the shifting operation of the automatic transmission, and there is a possibility that the riding comfort at the time of constant speed traveling may deteriorate.

The above-mentioned problem becomes remarkable when a gain correction is applied to the output so that the output characteristic of the engine becomes linear with respect to the throttle opening.

The present invention has been made based on the above-described circumstances, and an object thereof is to perform a shift operation of an automatic transmission even when an automobile runs on an uphill while traveling at a constant speed in overdrive. It is an object of the present invention to provide a constant-speed traveling device for a vehicle that can improve the riding comfort at the time of constant-speed traveling without causing hunting.

(Means for Solving the Problems) The present invention relates to a shift control means for shifting a gear position of an automatic transmission connected to an engine in accordance with a shift pattern set in advance based on a vehicle speed and a throttle opening, and an engine. A throttle control means for driving a throttle valve disposed in an intake system of the vehicle to adjust the throttle opening, and a traveling state detecting means for detecting a traveling state of the vehicle, wherein an output value from the traveling state detecting means is provided. The constant-speed traveling device for a vehicle that controls the operation of the throttle control unit and the speed-change control unit to cause the vehicle to travel at a constant speed at the target vehicle speed. A threshold line for the throttle opening defined according to the vehicle speed between the upshift line to the highest speed stage and the downshift line from the highest speed stage, and the target vehicle speed are maintained. In the meantime, target opening setting means for setting a target opening of the throttle valve, and comparing means for comparing a target opening set by the target opening setting with a set threshold set from a threshold line based on the vehicle speed. When the automatic transmission is at the highest speed and the set opening is larger than the set threshold by the comparing means, the target opening is limited to the set threshold and the speed of the automatic transmission is fixed at the highest speed. Gear position fixing means.

(Operation) According to the above-described constant-speed traveling device, when the vehicle is traveling at a constant speed with the automatic transmission at the highest speed, the throttle opening is limited to the set opening set by the threshold line. Therefore, the throttle opening of the throttle valve does not increase across the downshift line, and the shift speed of the automatic transmission is fixed to its highest speed.

(Embodiment) Hereinafter, a constant speed traveling device for a vehicle according to an embodiment will be described with reference to the drawings.

The constant-speed traveling device is applied to an automobile equipped with an engine 2 having an automatic transmission 1. In this case, the automatic transmission 1 has an overdrive speed.

The constant-speed traveling device performs a shift operation of the automatic transmission 1 and
A controller 4 for controlling the throttle opening of the throttle valve 3 is provided. Accordingly, the controller 4 drives the hydraulic shift operation mechanism 5 for performing a shift operation of the automatic transmission 1 and the throttle valve 3 to drive the throttle valve 3. Control signals are output to a throttle drive mechanism for changing the throttle opening, that is, the actuator 6. Here, the actuator 6 may be a negative pressure drive type actuator or the throttle valve 3
An electric motor or the like for rotating the valve shaft may be used.

The control signal from the controller 4 is output based on signals from various sensors and switches. The sensors include a vehicle speed sensor 7 and a throttle opening sensor 8 and the like. There are a switch 9, a set switch 10, a stop lamp switch 11, a resume switch 12, an inhibitor switch 13, an accelerator switch 14, and the like.

First, the basic operation of the constant-speed traveling device will be briefly described. The speed stage of the automatic transmission 1 is set to the overdrive speed which is the highest speed stage, and the driver turns on the main switch 9 so as to perform the constant speed traveling while the vehicle is traveling;
When the set switch 10 is turned on after confirming that the desired speed has been reached with a speedometer (not shown), the vehicle speed at this time is set to the target vehicle speed, and constant speed traveling control is started. You. After this, the controller 4 sets the target vehicle speed and the vehicle speed sensor 7 based on a predetermined control law.
The throttle opening of the throttle valve 3 is controlled via the actuator 6 according to the deviation from the actual vehicle speed obtained from the above, and the output of the engine 2 is adjusted to maintain the actual vehicle speed at the target vehicle speed. .

Here, the output characteristic of the engine 2 with respect to the throttle opening is as shown by a substantially broken line in FIG. 2, but in this embodiment, as shown by a solid line in FIG. On the other hand, gain correction is performed on the output of the engine 2 so that the output characteristic becomes linear.

Also, during normal traveling, when the vehicle travels uphill, the actual vehicle speed decreases, and accordingly, the throttle opening exceeds the downshift line defined in the shift map in the automatic transmission 1. When the automatic transmission 1 is widely opened, the automatic transmission 1 is automatically shifted down from the overdrive speed, thereby accelerating the acceleration of the vehicle. Therefore, if such a downshift is performed, the actual vehicle speed is promptly increased to the target vehicle speed. When the actual vehicle speed returns to the target vehicle speed and the load on the engine 2 is reduced, the throttle opening is greatly reduced, and the throttle opening is reduced beyond the upshift line of the shift map. In this case, the gear position of the automatic transmission 1 is shifted up and returned to the overdrive gear position, thereby returning to the overdrive constant speed traveling.

On the other hand, when the driver depresses the brake pedal (not shown) during the constant speed running in overdrive, and the stop lamp switch 11 as a cancel switch is turned on in conjunction with the brake pedal, the constant speed running is performed at this time. Control is released. Incidentally, when the automatic transmission 1 is switched to the neutral position and the driving force from the engine 2 is not transmitted to the wheels, the inhibitor switch 13 which operates in conjunction with a shift lever (not shown) of the automatic transmission 1 and functions as a cancel switch is operated. When the vehicle is turned on, the constant-speed traveling control is released, whereby the engine 2 is prevented from blowing up.

The resume switch 12 shown in FIG. 1 is for resuming the constant speed traveling control by turning on the constant speed traveling control after releasing the constant speed traveling control by depressing the brake pedal. Not limited to, during cruise control,
By holding down the resume switch 12, the car can be accelerated, and the function of setting the vehicle speed when the finger is released from the resume switch 12 to the new target vehicle speed can be added. During control, the set switch 10 is kept depressed to decelerate the car, and the set switch 10 may have a function of setting the vehicle speed at the time when the finger is released from the set switch 10 to a new target vehicle speed. Good.

In this embodiment, the maximum allowable value of the throttle opening degree during the constant speed traveling control of the vehicle in overdrive,
That is, a threshold line defining the throttle opening threshold θTH, that is, a throttle opening restriction line L is added to the shift map of the automatic transmission 1 described above. That is, as shown in FIG. 3, the shift map includes a dashed shift-up line based on the actual vehicle speed Va and the throttle opening degree θa.
→ OD shift line and shift-down line
The OD → 3 line is defined, and the aforementioned throttle opening limit line L is located between the 3 → OD shift line and the OD → 3 shift line, as is apparent from FIG. It is defined so as to have the same change characteristics as these shift lines. Note that the above-described shift map is actually stored in the storage device of the automatic transmission 1 itself.
The automatic transmission 1 automatically performs the shift operation according to the shift map based on the actual vehicle speed Va and the throttle opening θa transmitted from the controller 4.

Next, the constant speed traveling control executed by the controller 4 in accordance with the overdrive (OD) control routine shown in FIG. 4 will be described.

First, when the overdrive control routine of FIG. 4 is started, the target vehicle speed Vo has already been set by the set switch 10 as described above, and at this time, the gear position of the automatic transmission 1 The drive has been switched to the gear position. Therefore, at the start of the overdrive control routine, the actual vehicle speed Va is at the target vehicle speed Vo,
In addition, the throttle opening θa changes from 3 to 3 indicated by a broken line in FIG.
It is smaller than the OD shift line.

Assuming such a running state of the car, step
In S1, the actual vehicle speed Va and the throttle opening θa are read, and in the next step S2, the throttle opening threshold θTH is read from the actual vehicle speed Va based on the throttle opening restriction line L in FIG.

Then, when reaching step S3, in this step, it is determined whether or not the throttle opening θa is equal to or smaller than the throttle opening threshold θTH. Here, immediately after this control routine is started, the throttle opening θa is smaller than the broken line 3 → OD shift line in FIG.
The determination in step S3 is positive (Yes), and step S4
Proceed to.

In step S4, based on the sensor signal from the vehicle speed sensor 7, that is, the actual vehicle speed Va, the actual vehicle speed Va is set to the target vehicle speed.
In order to maintain Vo, throttle correction amount of throttle valve 3 Δ
θ is calculated and calculated. Here, the throttle correction amount Δ
θ is calculated in consideration of the speed deviation and the acceleration between the actual vehicle speed Va and the target vehicle speed Vo, and the jerk obtained by differentiating the acceleration.

Then, in the next step S5, the target throttle opening,
That is, it is determined whether or not θa + Δθ is equal to or smaller than the throttle opening threshold value θTH. If the determination here is positive, step
In S6, the throttle correction amount Δθ obtained in the previous step S4
Only, the throttle valve 3 is driven, and the control cycle described above is repeated. Accordingly, the actual vehicle speed Va is maintained at the target vehicle speed Vo by feedback-controlling the throttle opening θa in this manner.

By the way, when the constant speed traveling control in the overdrive is performed as described above, when the vehicle reaches an uphill and travels on the uphill, the actual vehicle speed Va is equal to the target vehicle speed. It will be greatly reduced from the vehicle speed Vo. Therefore, in such a situation, the aforementioned step S4
Is a large positive value, and the target throttle opening (θa + Δθ) also has a large value.

Here, if the target throttle opening (θa + Δθ) is equal to or smaller than the current throttle opening threshold θTH, the determination in step S5 remains positive, and thus the throttle calculated in step S4 as described above. According to the correction amount Δθ,
The throttle valve 3 is driven. However, if the determination in step S5 is negative (No), the process proceeds to step S6 via step S7. Steps
In S7, the throttle correction amount Δθ is calculated from the equation Δθ = θTH−θa. That is, if the determination in step S5 is negative, it means that the target throttle opening is equal to or greater than the throttle opening threshold θTH, but in this case, the throttle correction amount Δθ is Is set to the deviation between the throttle opening threshold θTH and the throttle opening θa. That is, if the determination in step S5 is negative,
In the next step S7, the target throttle opening is set to the throttle opening threshold θTH. Therefore,
In the next step S6, the throttle valve 3 is opened by the throttle opening threshold value θTH, whereby the actual vehicle speed Va is increased toward the target vehicle speed Vo.

When the next control cycle is executed, since the actual vehicle speed Va is increasing, as is apparent from FIG. 3, the throttle opening threshold value θTH is also increased, and accordingly,
In this case, the determination in step S3 is positive, and the above-described steps are repeatedly performed.

If the determination in step S3 is negative, that is, if the vehicle speed Va further decreases even if the throttle opening θa is changed in the opening direction, in step S8,
Step S6 is performed with the throttle correction amount Δθ set to 0. That is, in this case, the throttle valve 3 is not driven. Further, when such a situation continues for a predetermined time, it may be determined that the situation is not a situation in which constant-speed traveling in overdrive is performed, and the constant-speed traveling control may be canceled.

As is apparent from the above description, even when the throttle valve opening degree θa of the throttle valve 3 is controlled to maintain the actual vehicle speed Va at the target vehicle speed Vo during the constant speed traveling control in overdrive, this throttle opening The degree .theta.a does not exceed the throttle opening threshold .theta.TH obtained from the throttle opening restriction line L defined in the shift map of FIG. Therefore, during the constant speed running in the overdrive, the throttle opening θa of the throttle valve 3 does not exceed the OD → 3 shift line shown by the one-dot chain line in FIG. As a result, during the constant speed traveling control, the gear position of the automatic transmission 1 is maintained at the overdrive gear position, so that hunting does not occur in the gear shifting operation of the automatic transmission 1. In addition, the ride comfort during the constant-speed running control does not deteriorate.

Further, as shown in FIG. 2, when the output characteristic of the engine 2 is subjected to gain correction so that the output of the engine 2 changes linearly with respect to the throttle opening θa, a specific target vehicle speed or an uphill slope can be obtained. Depending on the degree of the gradient, hunting is likely to occur in the speed change operation of the automatic transmission 1 during the constant-speed traveling control. However, even in such a case, the value of the throttle opening θa falls within the throttle opening limit line L as described above. Hunting does not occur in the shifting operation.

FIG. 5 is a block diagram showing a control system for executing the above-described overdrive control routine. As is clear from FIG. 5, the throttle valve 3 obtains a throttle correction amount Δθ from a comparison between the throttle opening θa and the throttle opening threshold θTH. Based on the throttle correction amount Δθ, the actuator 6, The throttle valve 3 is driven.

The present invention is not limited to the above-described embodiment, and various modifications are possible. For example, there are various possible methods for restricting the throttle opening within the throttle opening threshold during the constant-speed running in overdrive, and the method is not limited to the method shown in the flowchart of FIG. Absent.

Further, in the shift map of FIG. 3, the throttle opening limit line L is located substantially at the center between the OD → 3 shift line and the 3 → OD shift line. → It may be positioned on the OD shift line side, and in this case, a large allowable maximum value of the throttle opening θa can be secured.

(Effect of the Invention) As described above, according to the constant speed traveling apparatus for a vehicle of the present invention, when the automatic transmission is set to the highest speed and the vehicle is traveling at a constant speed, the throttle of the throttle valve is controlled. Since the opening is restricted within a threshold line defined between the upshift line and the downshift line, the throttle opening does not greatly increase beyond the downshift line. Therefore, even when the vehicle is traveling uphill, for example, at a constant speed at the highest speed, the speed of the automatic transmission is maintained at the highest speed, and hunting occurs in the speed change operation. However, there is an effect that the ride comfort of the vehicle can be improved.

[Brief description of the drawings]

BRIEF DESCRIPTION OF THE DRAWINGS The drawings show an embodiment of the present invention, FIG. 1 is a schematic configuration diagram of a constant-speed traveling device, FIG. 2 is a graph showing an engine output characteristic with respect to a throttle opening, and FIG. FIG. 4 is a graph showing a throttle opening limit line defined by the throttle opening, FIG. 4 is a flowchart showing an overdrive control routine, and FIG. 5 is a schematic block diagram for executing the control routine. DESCRIPTION OF SYMBOLS 1 ... Automatic transmission, 3 ... Throttle valve, 4 ... Controller, 5 ... Hydraulic speed change operation mechanism, 6 ... Actuator, 7 ... Vehicle speed sensor, 8 ... Throttle opening degree sensor.

Claims (1)

(57) [Claims] 1. A shift control means for shifting a shift speed of an automatic transmission connected to an engine according to a shift pattern set in advance based on a vehicle speed and a throttle opening, and provided in an intake system of the engine. Throttle control means for driving the throttle valve to adjust the throttle opening, and running state detecting means for detecting a running state of the vehicle, wherein the throttle control means is provided based on an output value from the running state detecting means. And controlling the operation of the shift control means,
In the constant speed traveling device for a vehicle that causes a vehicle to travel at a constant speed at a target vehicle speed, the vehicle speed may be changed between a shift up line to a highest speed stage and a shift down line from the highest speed stage during the shift pattern of the shift control unit. A threshold line for throttle opening defined in accordance therewith, target opening setting means for setting a target opening of the throttle valve in maintaining a target vehicle speed, and a target opening setting means. Comparing means for comparing the target opening with a set threshold set based on the vehicle speed from the threshold line; and wherein the automatic transmission is at the highest speed and the target opening is set to be smaller than the set threshold by the comparing means. Speed limit fixing means for limiting the target opening to the set threshold value when the speed is large, and fixing the shift speed of the automatic transmission to the highest speed. apparatus.