JPH04218436A - Constant speed running device for car - Google Patents

Abstract

PURPOSE:To provide a constant-speed running device for car with which sufficient deceleration can be done in the running situation, where the distance to the foregoing car is short, and with which a favorable feeling of decelerating is obtainable. CONSTITUTION:Sensing values from a car speed sensor 8, inter-car distance sensor 9, etc., are fed to a controller 3, which makes opening/closing control of a throttle valve 6 so that constant speed running (auto-cruise) is performed at the target speed. When a decelerate command is given by a coast switch 17, the throttle valve 6 is closed fully, and in the condition that the actual inter-car distance is shorter than the set inter-car distance, an automatic transmission 2 is further shifted downward.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] This invention relates to a vehicle constant speed control system configured to perform constant speed driving control at a set target vehicle speed and to change the target vehicle speed by fully closing the throttle in response to a deceleration command. The present invention relates to a constant speed traveling device for a vehicle, and particularly relates to a constant speed traveling device for a vehicle that is combined with speed change control when controlled based on a deceleration command.

0002

[Background Art] Constant-speed driving control, so-called auto-cruise, has recently become known for vehicles, and in this control, steady driving is performed at a target speed set by the driver. It is designed to control the throttle opening.

On the other hand, by accelerating or decelerating the vehicle speed as appropriate,
Inter-vehicle distance control that follows the vehicle ahead at a predetermined distance is also known; for example, Japanese Patent Laid-Open No. 61-93
Japanese Patent No. 43 proposes a system that notifies the driver of insufficient deceleration during follow-up travel to alert the driver.

By the way, in constant speed driving control, there is a control mode in which the vehicle decelerates in accordance with a deceleration command from the driver, and as long as the driver continues to press a so-called coast switch, the throttle is kept fully closed, thereby reducing the vehicle speed. I'm trying to reduce it.

[0005]

[Problem to be Solved by the Invention] However, in this type of deceleration control, since the deceleration is not actively decelerated by brake operation etc., there is not much sense of deceleration, and the distance between the vehicle and the vehicle in front is close to some extent. In driving conditions,
Although deceleration is reliably achieved by fully closing the throttle, this is not sufficient in terms of giving the driver a sufficient sense of deceleration and, ultimately, a sense of security.

The present invention was made in view of the above background, and it is possible not only to ensure sufficient deceleration in driving situations where the distance between vehicles is close to a certain extent, but also to provide a feeling of deceleration that is favorable to the driver. The object of the present invention is to provide a constant speed traveling device for a vehicle that can provide the following characteristics.

[0007]

[Means for Solving the Problems] In order to achieve the above object, the present invention performs constant speed driving control at a set target vehicle speed, and also changes the target vehicle speed by fully closing the throttle in response to a deceleration command. The constant speed traveling device for a vehicle is configured to include an inter-vehicle distance detection means for detecting an inter-vehicle distance to a preceding vehicle, and to detect an actual inter-vehicle distance input from the inter-vehicle distance detection means when the deceleration command is input. The present invention is characterized in that a control means for downshifting the transmission when the inter-vehicle distance is less than a preset set inter-vehicle distance is provided.

[0008]

[Operation] To describe the operation of the present invention, when a deceleration command is input and the actual inter-vehicle distance to the vehicle in front is shorter than the set inter-vehicle distance, the transmission is downshifted by the control means. become. Therefore, in addition to the original deceleration control by fully closing the throttle, deceleration is also performed by downshifting the transmission, making it possible to obtain sufficient deceleration and to give the driver a favorable sense of deceleration. .

[0009]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a configuration diagram showing a preferred embodiment of the present invention, in which an engine 1 mounted on a vehicle is shown.
The control system associated with this is shown.

The engine 1 has an automatic transmission 2 connected to its output shaft to form a so-called engine with an automatic transmission, and each part is appropriately controlled by a controller 3. The automatic transmission 2 includes a torque converter 4 and a planetary gear mechanism 5, and the rotational driving force of the engine 1 is outputted via the torque converter 4 and the planetary gear mechanism 5 to a propeller shaft (not shown).

The planetary gear mechanism 5 is equipped with a solenoid valve mechanism 50 that mechanically switches its gear stage, and this solenoid valve mechanism 50 is operated by a solenoid valve drive circuit 51. A control signal is sent to the solenoid valve drive circuit 51 from the controller 3 as a control means, and based on the control signal, the solenoid valve mechanism 5
0 is driven, and in this way, speed change control such as upshifting or downshifting in the planetary gear mechanism 5 is performed.

The controller 3 is equipped with a so-called control computer, and receives a large number of detection signals from various sensors in order to determine the running state of the vehicle, the operating state of the engine 1, and the like. That is, the controller 3 includes a throttle opening sensor 7 that detects the opening of the throttle valve 6 provided in the intake passage 10 of the engine 1.
, a vehicle speed sensor 8 that detects the output rotation speed from the planetary gear mechanism 5 as a vehicle speed, an inter-vehicle distance sensor 9 as inter-vehicle distance detection means that detects the actual inter-vehicle distance to the vehicle in front, and an accelerator 1
Signals are input from the accelerator sensor 12 that detects the depression operation of the brake 13, the brake switch 14 that detects the depression operation of the brake 13, etc., and the main switch 15 that starts the constant speed driving control, the constant speed control that is operated by the driver. In addition to shifting to speed traveling control, after operating the set switch 16 that sets the vehicle speed at the time of the operation as the target vehicle speed, the coast switch 17 that instructs a deceleration command, the brake 13 or the coast switch 17, control is returned to the previously set target vehicle speed. Resume switch 18 for instructing a return command to return
Signals from various switches related to constant speed running control are input, and control signals according to a predetermined control program are sent to the solenoid valve drive circuit 51, the throttle actuator 19 that opens and closes the throttle valve 6, etc., and controls the running speed. Control is executed.

FIG. 2 is a flowchart schematically showing constant speed running control. In the control flow for constant speed driving shown here, the main switch 15 is ON and the set switch 1 is ON.
This is when the target vehicle speed is set by operating 6 and the vehicle is already in a steady constant speed running state, that is, autocruise. When this auto cruise is in effect, the running load is first determined (S1), and then a condition is determined as to whether to continue or cancel the control (S2,
S3). That is, when determining the depression operation of the brake 13 (
(S2, YES) or when it is determined that the accelerator 11 is depressed (S3, YES), autocruise is canceled and normal control is returned. Here, if there is a depression operation on the brake 13 (S2, YES), a flag indicating the depression operation on the brake 13 is used as a flag for determining whether or not the operation determination of the resume switch 18 in the subsequent stage is performed. 1 is placed in SETF (S20). On the other hand, in other control states, auto-cruise is continued, and after these determinations, the operation of each of the set switch 16, coast switch 17, and resume switch 18 is sequentially monitored (S
4, S5, and S7), the flag SETF described above and the flag COSTF described later are also monitored (S6).

When the set switch 16 is turned on (S4
, YES), the current vehicle speed VSP is stored as the target vehicle speed SETV (S40), and constant speed control is performed using the new target vehicle speed SETV (S8), but the ON operation of the set switch 16 continues for more than a predetermined time. If (S41, YE
S) Perform separate acceleration control (S9).

When the coast switch 17 is turned on (S
5, YES), sends a control signal to the throttle actuator 19 to fully close the throttle valve 6 (S50), stores the reduced current vehicle speed VSP as a new target vehicle speed SETV (S51), and switches the coast switch. 1
Set the flag COSTF indicating operation 7 to 1 (S
52).

[0016] Next, the process moves to the judgment of the operation of the resume switch 18 (S7), and the return control operation by the resume switch 18
Alternatively, this is performed assuming a deceleration state due to the ON operation of the coast switch 17, and therefore, the determination of the flags SETF and COSTF described above is performed prior to the determination of the operation of the resume switch 18 (S6). Here, if either of these flags SETF and COSTF is 1 (S6, YES), it is assumed that deceleration control has been performed once, and return control is appropriate, and therefore the operation of the resume switch 18 is determined. (S
7). On the other hand, if both flags are 0, it is determined that there was no deceleration operation before (S6, NO
), constant speed control is executed without determining whether the resume switch 18 is operated (S8).

When the resume switch 18 is turned on (
S7, YES), sets the flag RESUF indicating the operation of the resume switch 18 to 1 (S70), until the vehicle speed VSP reaches the lower limit of the target vehicle speed SETV (vehicle speed in S40) before the brake 13 or coast switch 17 is operated. (S71, NO) Performs acceleration control (S71, NO)
9). Here, in the first loop, the control moves from S7 to S70, but in the second and subsequent loops, it is determined that the flag RESUF is 1 (S73, YES).
) control will flow. Then, when the lower limit value is exceeded (S71, YES), each flag RESUF, SET
Reset F to 0 (S72) and return to constant speed control (
S8). Note that if the resume switch 18 is not operated (S7 and S73, NO), the current control state will be maintained.

Now, FIG. 3 is a flowchart schematically showing the speed change control in constant speed driving control. When in autocruise, the control flow shown in FIG. 3 is activated and executed also in shift control. That is, when the gear shift control is in auto cruise mode, the set switch 16, coast switch 17, and resume switch 18 are activated.
We are sequentially monitoring the operation of each (
T1, T2, T3), and in a situation where the vehicle speed VSP has not converged to a predetermined range centered on the target vehicle speed SETV (T4,
NO), sends a control signal to the solenoid valve drive circuit 51 to downshift the gear stage of the planetary gear mechanism 5 (T5),
Perform appropriate acceleration/deceleration.

On the other hand, in the ON operation of the set switch 16 (T1, YES), when the ON operation continues for longer than a predetermined time (T10, YES), if the running load is greater than the predetermined value (T11) , YES), the gear is downshifted (T5) and accelerated.

In particular, in the present invention, when the coast switch 17 is turned ON (T2, YES), if the actual distance to the vehicle in front is less than the set distance (T20, YES),
In S), the gear stage is downshifted (T5) in addition to the above-described fully closed throttle control (S50) to promote deceleration.

When the resume switch 18 is turned on (
T3, YES), if the running load is greater than the predetermined value (
T30, YES), shift down the gear (T5)
,To accelerate.

Note that the running load is determined by checking the magnitude of the actual throttle opening with respect to a reference value stored in advance.Since the throttle opening under a standard load condition is used as the reference value, the actual throttle opening is When the degree is larger than this reference value, the running load is large, and conversely, when it is smaller, the running load is small.

This invention basically consists of a set switch 1
6 is turned ON, the vehicle is controlled to run at a constant speed at the set target vehicle speed SETV, and the throttle valve 6 is fully closed in response to a deceleration command caused by the ON operation of the coast switch 17, thereby changing the target vehicle speed SETV. A constant speed traveling device for a vehicle is provided with an inter-vehicle distance sensor 9 that detects the inter-vehicle distance to the vehicle in front, and a set inter-vehicle distance in which the actual inter-vehicle distance input from the inter-vehicle distance sensor 9 is preset when a deceleration command is input. 3, the controller 3 is configured to include a control means for downshifting the automatic transmission 2 when Configure (T2→T20→T5).

According to such a configuration, when a deceleration command is input by turning on the coast switch 17, if the actual distance to the vehicle in front is shorter than the set distance, the controller 3 automatically Transmission 2
is shifted down, so that in addition to the original deceleration control by fully closing the throttle valve 6, the speed is also decelerated by the speed change control of the automatic transmission 2. Therefore, it is possible to obtain sufficient deceleration when the vehicle is running with a short inter-vehicle distance, and it is also possible to provide the driver with a favorable feeling of deceleration. On the other hand, if there is a considerable distance between the vehicles, the downshift is not performed, so no unnecessary deceleration control is performed, and the vehicle can be driven comfortably without spoiling the sense of continuous driving.

[0025]

[Effects of the Invention] As explained in detail in the embodiments above, according to the constant speed traveling device for a vehicle according to the present invention, when a deceleration command is input, the actual inter-vehicle distance to the preceding vehicle is shorter than the set inter-vehicle distance. When the vehicle is in a running state, the transmission is downshifted by the control means, so that in addition to the original deceleration control by fully closing the throttle, deceleration can also be achieved by shift control of the transmission. Therefore, it is possible to obtain sufficient deceleration when the vehicle is running with a short inter-vehicle distance, and it is also possible to provide the driver with a favorable feeling of deceleration. On the other hand, if there is a considerable distance between vehicles, downshifting is not performed, so the vehicle can be driven comfortably without losing the sense of continuity in driving.

[Brief explanation of the drawing]

FIG. 1 is a configuration diagram showing an embodiment of the present invention.

FIG. 2 is a flowchart schematically showing constant speed driving control.

FIG. 3 is a flowchart schematically showing shift control in constant speed driving control.

[Explanation of symbols]

2 Transmission (automatic transmission) 3 Control means (controller) 6 Throttle (throttle valve) 9 Inter-vehicle distance detection means (inter-vehicle distance sensor) SETV
Target vehicle speed

Claims (1)

[Claims] Claim 1. A constant speed traveling system for a vehicle configured to perform constant speed traveling control at a set target vehicle speed and to change the target vehicle speed by fully closing the throttle in response to a deceleration command. In addition to providing inter-vehicle distance detection means for detecting the inter-vehicle distance to the vehicle, when the deceleration command is input,
A constant speed traveling device for a vehicle, comprising a control means for downshifting a transmission when an actual inter-vehicle distance inputted from the inter-vehicle distance detection means is less than a preset set inter-vehicle distance.