JPH04238744A - Running control device for vehicle - Google Patents

Abstract

PURPOSE:To provide a vehicle running control device which can well improve dynamic characteristic of intercar distance control despite a distance between cars and ensure running suited for a condition. CONSTITUTION:A detection value of an intercar distance sensor 7 or the like is fed to a controller 3 in which a throttle valve 4 is controlled opened/closed so as to converge a front vehicle to a target distance between cars. When the actual intercar distance is large as compared with the target intercar distance, a control gain in a control means is decreased, and in a reverse condition, the control gain is increased. That is, responsiveness of control is suitably changed in accordance with a running condition of a vehicle.

Description

[Detailed description of the invention]

0001

[Industrial Field of Application] This invention relates to an inter-vehicle distance detection means for detecting the actual inter-vehicle distance between the vehicle in front and the own vehicle, a target inter-vehicle distance setting means for setting a target inter-vehicle distance, and a The present invention relates to a vehicle travel control device having a control means for controlling an inter-vehicle distance so that the following distance is maintained, and particularly relates to a vehicle travel control device that appropriately changes the dynamic characteristics of control depending on the vehicle travel situation.

0002

[Prior Art] In recent years, forward vehicle following control, also known as so-called inter-vehicle distance control, has become known for vehicles. In this control, the inter-vehicle distance between the vehicle in front and the own vehicle is detected using a sensor, etc. The detected actual inter-vehicle distance is compared with a predetermined target inter-vehicle distance, and the driving state of the vehicle is controlled so that the actual inter-vehicle distance becomes the target inter-vehicle distance. For example, in Japanese Patent Application Laid-Open No. 61-6031, it is of course necessary to maintain the actual distance between the vehicle in front and the target vehicle distance,
A system has been proposed in which this target inter-vehicle distance can be adjusted.

0003

[Problems to be Solved by the Invention] In such inter-vehicle distance control, there is a desire to improve the dynamic characteristics of the control, but there are the following problems. That is, based on the premise that the actual inter-vehicle distance is to be converged to the target inter-vehicle distance, the dynamic characteristics of this inter-vehicle distance control are set based on the target inter-vehicle distance. In such a setting, even if the sensor detects the vehicle ahead at a distance considerably further than the target inter-vehicle distance, and even if gradual convergence control is preferable, the dynamic characteristics near the target inter-vehicle distance will be affected. Convergence control would be performed with characteristics similar to those described above, and there was a risk that the control would become jerky due to excessive response. If, on the other hand, the dynamic characteristics of the control are set to be gentler, this will appear as a sluggish response when the distance between the vehicle and the vehicle in front is narrow, making it uncomfortable for the driver. There was a risk.

The present invention has been made in view of the above-mentioned background, and it is an object of the present invention to improve the responsiveness of inter-vehicle distance control, regardless of the inter-vehicle distance when the sensor captures the vehicle in front. The object of the present invention is to provide a vehicular travel control device that can obtain the desired control dynamic characteristics regardless of the inter-vehicle distance, and can promote smooth travel control suitable for the situation.

[0005]

[Means for Solving the Problems] In order to achieve the above object, the present invention provides an inter-vehicle distance detection means for detecting the actual inter-vehicle distance between the preceding vehicle and the own vehicle, and a target inter-vehicle distance setting in which a target inter-vehicle distance is set. and a control means for controlling the inter-vehicle distance so that the actual inter-vehicle distance becomes the target inter-vehicle distance, when the actual inter-vehicle distance is larger than the target inter-vehicle distance, the control means The present invention is characterized by comprising a gain changing means for decreasing the control gain of the control means, and increasing the control gain of the control means when the actual inter-vehicle distance is smaller than the target inter-vehicle distance.

[0006]

[Operation] With the above configuration, when the actual inter-vehicle distance is larger than the target inter-vehicle distance, that is, when the vehicle ahead is far away, the control gain is reduced by the gain changing means, so that the responsiveness of the control is improved. becomes gradual. On the other hand,
In the opposite situation, that is, when the vehicle ahead is at a certain distance, the control gain is increased, so the control response becomes quick.

[0007]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, embodiments of the present invention will be described with reference to the accompanying drawings. FIG. 1 is a block diagram showing a preferred embodiment of the present invention, in which a control system linked to an engine 1 mounted on a vehicle is shown. In this embodiment, a control system that combines constant speed driving control and inter-vehicle distance control is exemplified, and the basic configuration of the control is that when a preceding vehicle is not detected, constant speed driving control is prioritized, and On the other hand, when a vehicle ahead is captured, priority is given to inter-vehicle distance control.

[0008] A transmission 2 is connected to the output shaft of the engine 1, and the transmission 2 outputs rotational driving force to the propeller shaft according to the selected gear position. , each part is appropriately controlled by the controller 3.

The controller 3 is equipped with a so-called control computer, to which a large number of detection signals from various sensors are inputted in order to judge 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 5 that detects the opening of the throttle valve 4 provided in the intake passage 10 of the engine 1.
, a vehicle speed sensor 6 that detects the output rotational speed from the transmission 2 as a vehicle speed, an inter-vehicle distance sensor 7 as inter-vehicle distance detection means that detects the actual inter-vehicle distance to the preceding vehicle, and an accelerator sensor 9 that detects the depression operation of the accelerator 8. , a brake switch 12 that detects the depression of the brake 11, a rain sensor 13 that detects rainy weather, etc. are input, and a main switch 14 that starts constant speed driving control is operated by the driver to start driving at a constant speed. A set switch 15 that shifts to control and sets the vehicle speed at the time of the operation as the target vehicle speed.
, a coast switch 16 that instructs a deceleration command, and a resume switch 17 that instructs a return command that returns control to the previously set target vehicle speed after operating the brake 11 or coast switch 16. A signal is input, and a control signal based on a predetermined control program is sent to a throttle actuator 18 that opens and closes the throttle valve 4, etc., and travel control is executed.

FIG. 2 is a flowchart schematically showing constant speed driving control, and FIG. 3 is a flowchart schematically showing a processing portion related to inter-vehicle distance control related to constant speed driving control. The control flow for constant speed driving shown in FIG. 2 is performed when the main switch 14 is ON, the target vehicle speed is set by operating the set switch 15, and the vehicle is already in a steady constant speed driving state, that is, autocruise. belongs to. 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 it is determined that the brake 11 is depressed (S2, YES) or when it is determined that the accelerator 8 is depressed (S3, YES), autocruise is canceled and normal control is returned. Here, if there is a depression operation on the brake 11 (S2, YES), a flag indicating the depression operation on the brake 11 is used as a flag for determining whether or not to make a judgment on the operation of the resume switch 17 in the subsequent stage. 1 is placed in SETF (S20). On the other hand, in other control states, auto cruise continues, and after these determinations, the set switch 15, coast switch 16, and resume switch 1 are activated.
7 operations are sequentially monitored (S4,
In addition to S5 and S7), the flag SETF described above and the flag COSTF described later are also monitored (S6).

When the set switch 15 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 15 continues for more than a predetermined time. If (S41, YE
S) Perform separate acceleration control (S9).

When the coast switch 16 is turned on, (S
5, YES), sends a control signal to the throttle actuator 18 to fully close the throttle valve 4 (S50), stores the decelerated current vehicle speed VSP as a new target vehicle speed SETV (S51), and switches the coast switch. 1
Set the flag COSTF indicating operation 6 to 1 (S
52).

[0013] Next, the process moves to the operation determination of the resume switch 17 (S7), and the return control operation by the resume switch 17
Alternatively, this is performed assuming a deceleration state due to the ON operation of the coast switch 16, 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 17 (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 17 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 17 is operated (S8).

When the resume switch 17 is turned on (
S7, YES), sets the flag RESUF indicating the operation of the resume switch 17 to 1 (S70), until the vehicle speed VSP reaches the lower limit of the target vehicle speed SETV (vehicle speed in S40) before the operation of the brake 11 or coast switch 16. (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 17 is not operated (S7 and S73, NO), the current control state will be maintained.

In the present embodiment, inter-vehicle distance control is combined with such constant speed running control. This inter-vehicle distance control is shown in FIG. 3, and is executed with priority over constant-speed driving control when the inter-vehicle distance sensor 7 detects a vehicle ahead.

At this time, a target inter-vehicle distance setting means for setting the target inter-vehicle distance, a control means for controlling the inter-vehicle distance so that the actual inter-vehicle distance becomes the target inter-vehicle distance, and a control means for controlling the inter-vehicle distance so that the actual inter-vehicle distance becomes the target inter-vehicle distance. When the actual inter-vehicle distance is smaller than the target inter-vehicle distance, the control gain of the control means is increased.The gain changing means is set in the controller 3. Constructed by program.

First, the sensor 7 checks whether or not the vehicle in front is captured, and the situation where the vehicle in front is not captured (S900) is determined.
, NO), the constant speed running control mode is entered, and at this time the control as described above is performed (S901).

On the other hand, in a situation where the preceding vehicle is detected by the sensor 7 (S900, YES), the vehicle-to-vehicle distance control mode is entered, and at this time, the target vehicle-to-vehicle distance TDIS is first set (S902 to S905).

The target inter-vehicle distance TDIS is a standard inter-vehicle distance set in order to follow the vehicle in front.
When the vehicle speed is high, the stopping distance also increases, so the target inter-vehicle distance TDIS is also set to be large, and in this way, the target inter-vehicle distance TDIS is determined with respect to the vehicle speed. To explain this graphically, as shown in Figure 4,
The target inter-vehicle distance TDIS is set larger as the vehicle speed increases, and the controller 3 has a so-called comparison table (map).
It is equipped with the following configuration. In particular, it is equipped with a steady map for when the road surface is dry and a rain map for when the road surface is wet, and the target inter-vehicle distance TDIS at the same vehicle speed is set larger in the rain map than in the steady map. be done. Therefore, the target inter-vehicle distance TDIS
In the setting, first check the detection value of the rain sensor 13 (S
902), if it is raining (S902, YES), input the rainy weather map (S903), and if it is not raining (S902), input the rainy weather map (S903).
02, NO) A steady map is input (S904), and a target inter-vehicle distance TDIS corresponding to the current vehicle speed is read out from any of the input maps (S905). After that, in general, a control gain is determined according to the driving situation of the vehicle (S906 to S910), and a control amount is determined from the deviation between the target inter-vehicle distance TDIS and the actual inter-vehicle distance DIS for inter-vehicle distance control. This is the throttle actuator 18
The process of sending the control signal as a control signal (S911) is performed. In this embodiment, inter-vehicle distance control (S911) is vehicle speed feedback control, and here control is performed based on a control gain (S910) determined according to the driving situation of the vehicle.

The control gain is set by reading a comparison table (map) of the control gain with respect to the variable ΔDIS of the actual inter-vehicle distance DIS, which is provided in the controller 3. The variable ΔDIS is the amount of variation in the actual inter-vehicle distance DIS in a unit period, and the gain map is shown in Figure 5 (
Two types of gain maps are provided: a far-field gain map as shown in A) and a near-field gain map shown in FIG. 5(B). That is, in the far-field gain map, the control gain is the variable ΔD
While IS is small, the gain is set smaller than the standard gain, increases as the variable ΔDIS increases, and finally becomes larger than the standard gain. In the proximity gain map, the control gain is always larger than the standard gain regardless of the increase or decrease in the variable ΔDIS. Here, when the actual inter-vehicle distance DIS is larger than the target inter-vehicle distance TDIS (S906, YES), a long distance gain map is input (S907), but in the opposite situation, that is, when the actual inter-vehicle distance DI
When S is less than or equal to the target inter-vehicle distance TDIS (S906, NO
), input the proximity gain map (S908),
From any of the input gain maps, a control gain corresponding to the currently calculated variable ΔDIS (S909) is set (S910). Therefore, in a situation where the actual inter-vehicle distance DIS is larger than the target inter-vehicle distance TDIS (S906, YES), the determined control gain is
Unless DIS is large to a certain extent, it is set small by reading the far-field gain map, and in the opposite situation (S906, NO), it is set large by reading the near-field gain map.

This embodiment basically includes an inter-vehicle distance sensor 7 that detects the actual inter-vehicle distance DIS between the vehicle in front and the own vehicle;
In a vehicle travel control device, the vehicle travel control device includes a target inter-vehicle distance setting means in which a target inter-vehicle distance TDIS is set, and a control means for controlling the inter-vehicle distance so that the actual inter-vehicle distance DIS becomes the target inter-vehicle distance TDIS. When the actual inter-vehicle distance DIS is large, the control gain of the control means is reduced, and when the actual inter-vehicle distance DIS is smaller than the target inter-vehicle distance TDIS, the control gain of the control means is increased. In this embodiment, the controller 3 serves as the gain changing means, as can be seen by operating according to the above-described control flow shown in FIG.

According to such a configuration, the target inter-vehicle distance T
When the actual inter-vehicle distance DIS is larger than DIS, that is, when the vehicle ahead is far away, the control gain is reduced by the gain changing means, so the dynamic characteristics become slow response, and the control becomes jerky. You can run smoothly without any problems. On the other hand, in the opposite situation, that is, when the distance between the vehicle and the vehicle in front is narrowed to some extent, the control gain is increased, resulting in a quick dynamic response and smooth driving suited to the situation without causing discomfort to the driver. Therefore, it has excellent safety.

[0023] Regarding the readout of the far-field gain map, the gain is reduced and the response is slow due to the variable Δ.
This is the case when DIS is not large to a certain extent, and even if the vehicle ahead appears far away, when the variable ΔDIS is large, that is, when the change in the actual inter-vehicle distance DIS is large, the gain is increased, so such a change in the actual inter-vehicle distance DIS Since the driver can respond quickly and prevent delays in response, the driver can respond favorably to changes in the situation without causing any discomfort during driving.

[0024] Therefore, no matter what distance the sensor 7 captures the vehicle in front, the responsiveness of the inter-vehicle distance control can be favorably obtained. It can be ensured well regardless of the situation, and smooth driving control suitable for the situation can be promoted.

[0025]

[Effects of the Invention] As explained in detail in the examples above,
According to the vehicle travel control device according to the present invention, when the vehicle ahead is far away, the control gain is reduced, so the response of the control becomes gentle, and therefore the control is not jerky and the vehicle travels smoothly. can. On the other hand, when the vehicle in front is close to a certain distance, the control gain is increased and the response of the control becomes quick, which results in smooth driving suited to the situation without causing discomfort to the driver, which improves safety. Excellent. Here, the dynamic characteristics of the control can be favorably improved regardless of the inter-vehicle distance, and smooth follow-up control suitable for the situation can be promoted.

[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 inter-vehicle distance control related to the control flow of FIG. 2;

FIG. 4 is a graph schematically showing the relationship between target inter-vehicle distance and vehicle speed.

FIG. 5 is a graph schematically showing the relationship between control gains for far and near distances and variables of inter-vehicle distance.

[Explanation of symbols]

3 Controller 7 Vehicle distance sensor

Claims (1)

[Claims] Claim 1: Inter-vehicle distance detection means for detecting the actual inter-vehicle distance between the preceding vehicle and the host vehicle; target inter-vehicle distance setting means for setting a target inter-vehicle distance; In a vehicle cruise control device having a control means for distance control, when the actual inter-vehicle distance is larger than the target inter-vehicle distance, a control gain in the control means is made smaller; A vehicular travel control device comprising gain changing means for increasing a control gain of the control means when the actual inter-vehicle distance is small.