JPH1142956A - Vehicular running control device - Google Patents

Abstract

PROBLEM TO BE SOLVED: To promptly transfer a following-up running situation to a constant speed running situation in the absence of a preceding car. SOLUTION: In the presence of a preceding car, an inter-vehicle control ECU 12 computes acceleration for following up with the inter-vehicle distance maintained and directs an engine ECU 14. In the absence of the preceding car, the inter-vehicle distance control ECU 12 directs acceleration for constant speed running at established speed to the engine ECU 14. When a situation is changed from the presence of the preceding car to the absence of the preceding car, the engine ECU 14 is gently accelerated up to the established speed after taking safety into account. When a driver operates a cruising control switch 18, acceleration at a higher rate is applied up to the established speed. The result prevents the distance between the preceding car and the followingup car from sudden reduction to enhance driving feeling.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

TECHNICAL FIELD The present invention relates to a vehicle traveling control device,
In particular, it relates to acceleration control at the time of transition from following running to constant speed running.

[0002]

2. Description of the Related Art Conventionally, radar means having a predetermined detection area for detecting an object (such as a preceding vehicle) existing in front of a vehicle is mounted on the vehicle, and the vehicle is mounted on the basis of the detection result of the radar means. Vehicle running control devices for controlling the running speed have been developed. In particular, there is known a system in which, when there is a preceding vehicle, the vehicle follows the vehicle while maintaining a constant inter-vehicle distance with the preceding vehicle, and when there is no preceding vehicle, the vehicle travels at a constant speed at a set vehicle speed. As disclosed in Japanese Patent Application Laid-Open No. 5-156977, there is known a technique in which a target inter-vehicle distance and a target vehicle speed are appropriately changed by an adjustment lever at hand.

[0003]

In such a traveling control system, when the preceding vehicle does not exist, the vehicle travels at a constant speed at a set vehicle speed. However, when the current vehicle speed is lower than the set vehicle speed, the vehicle travels at a constant speed after accelerating to the set vehicle speed. It will shift to running. The acceleration at this time is given as a fixed value obtained by an experiment or the like in advance at a level at which the driver does not feel uncomfortable. Here, for example, in the case of exiting from the highway along a curve entrance or a preceding vehicle, losing sight of the preceding vehicle for a moment starts the acceleration control by the fixed value, and then starts deceleration control by re-detection. In consideration of the occurrence of control hunting, the fixed value is set so as not to cause a large acceleration.

However, in the acceleration control using the fixed value,
On the contrary, when the preceding vehicle leaves the course, the driver will feel a sense of insufficient acceleration, and in order to prevent this, the driver has to operate the accelerator pedal which has not been used before, which is troublesome. There was a problem.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has an object to shift from following running to a constant speed running state since a state where a preceding vehicle is present has been changed to a state where there is no preceding vehicle. In this case, it is an object of the present invention to provide a travel control device capable of obtaining a sufficient acceleration without operating the accelerator pedal when necessary and realizing a smooth travel.

[0006]

According to a first aspect of the present invention, there is provided a control apparatus for following a vehicle when a preceding vehicle is present and traveling at a constant speed at a set vehicle speed when there is no preceding vehicle. And a control for increasing the speed of the vehicle to the set vehicle speed with an acceleration greater than that at the time of non-operation when the operating means is operated when shifting from the following running to the constant speed running. Means.

According to a second aspect of the present invention, in the first aspect, the operation means is also used as a resume switch for returning from a control non-operation state to an operation state.

[0008]

Embodiments of the present invention will be described below with reference to the drawings. In the following description,
"Cruise control" or "cruise function" means that if there is a preceding vehicle, the vehicle follows the vehicle while keeping the distance to the preceding vehicle at the target distance, and if there is no preceding vehicle, it is set by the driver This means running at a constant speed at the vehicle speed.

FIG. 1 is a block diagram showing the overall configuration of the embodiment. A scanning type laser radar 10 is provided on a front bumper of the vehicle, and sends a laser beam forward, and a distance and a direction from a reflected light to an object ahead,
Detect relative speed. An inter-vehicle control ECU (electronic control unit) 12 is connected to the scan type laser radar 10 to determine a vehicle to follow based on data from the laser radar 10 so that an interval with the following vehicle becomes a target interval. The acceleration (or deceleration) is determined. Vehicle control ECU
An engine ECU 14 is connected to 12 and realizes a cruise control function based on data from the headway control ECU 12. Specifically, this engine ECU
14 has an electronic throttle actuator 24 and an ECT
(Electronic control transmission) A solenoid 26 is connected and drives an electronic throttle actuator in accordance with a target acceleration supplied from the headway control ECU 12.
Alternatively, in response to a downshift request (deceleration request) supplied from the following distance control ECU 12, the shift is changed to a low speed side to cause engine braking.

The engine ECU 14 has an ECT mode switch 16, a cruise control switch 18,
A stop lamp switch 20 and a vehicle speed sensor 22 are connected. The cruise control switch 18 is for performing each operation of ON / OFF of the cruise function of the engine ECU 14, setting of the vehicle speed, acceleration, deceleration, and control cancellation, and details thereof will be described later. EC
The T mode switch 16 is a switch for the driver to set an ECT mode (for example, a power mode or a snow mode). When the driver sets the ECT mode to a snow mode (a mode in which the vehicle can start in a second gear). Means that the engine ECU 14 cancels the cruise function. This is to prevent the cruise control from being performed on slippery roads such as snowy roads and icy roads. The cruise function can be canceled by canceling the cruise function in operation or by turning on the cruise function using the cruise control switch 18. This includes prohibiting the transition to the cruise function even at times. Note that the driver does not operate the ECT mode switch 16 but the engine ECU 14
When the ECT is automatically set to the snow mode by detecting that the wheel is slipping on the basis of the wheel speed and the output from the G sensor inside, and determining that the road is a low friction road (low μ road),
It is desirable to cancel the cruise function at the same time as setting the snow mode. The stop lamp switch 20 is for detecting a brake operation by the driver,
Engine EC when the driver performs the brake operation
U14 cancels the cruise function.

A VSC (vehicle attitude stabilization control) -ECU 28 is connected to the engine ECU 14.
A steering sensor 30 and a warning buzzer 32 are connected to the C-ECU 28. When the VSC-ECU 28 detects that the vehicle has over-steered or under-steered based on the detection from the steering sensor 30, the VSC-ECU 28 lowers the output of the engine and applies a braking force to the front wheels or the rear wheels to stabilize the turning motion of the vehicle. When the system operates, the warning buzzer 32 is driven to alert the driver. However, if the inter-vehicle distance with the following vehicle is too close during the cruise function, the engine ECU 14 sets the VSC-. The alarm buzzer 32 is driven via the ECU 28 to call the driver's attention (for example,
(E.g., an audible alarm sounds). That is, the alarm buzzer 32 has both functions of the VSC operation alarm and the inter-vehicle alarm during the cruise function. The steering angle detected by the steering sensor 30 is used for the VSC and is also supplied to the engine ECU 14 to be used particularly for a cruise function on a curved road.

Various devices are connected to the engine ECU 14 via a body multiplex communication system 34. Specifically, a tail lamp switch 36, a wiper switch 3
8. Meter 40 is connected. The tail lamp switch 36 is for detecting the lighting of the tail lamp, that is, night driving, and when the tail lamp switch is in the ON state, the engine ECU 14 sets the target inter-vehicle distance to be longer than during the day. A specific setting method will be described later. Further, the wiper switch 38 is for detecting the operation state of the wiper, that is, running in rainy weather.
When the wiper switch 38 is ON, the engine ECU 14 cancels the cruise function. The meter display 40 is one of the features of the present embodiment, and displays information specific to the cruise function in addition to the normal speed and the engine speed. The information specific to the cruise function includes detection of a preceding vehicle, an inter-vehicle time representing an inter-vehicle distance, a set vehicle speed, a state of the cruise function, a fail mode, and the like. The inter-vehicle time is a physical quantity expressing the inter-vehicle distance by time, and has a relation of inter-vehicle time = inter-vehicle distance / vehicle speed. Therefore,
There is a target inter-vehicle time corresponding to the target inter-vehicle distance that is the target of the follow-up control at a ratio of 1: 1. In this embodiment, the inter-vehicle time switch 44 is provided so that the target inter-vehicle time can be appropriately adjusted by the driver. The inter-vehicle time changeover switch 44 is connected to the meter display 40, the inter-vehicle time set by the driver is displayed on the display as it is, and the engine ECU is connected via the body multiplex communication system 34.
14 and used for cruise control.
As the inter-vehicle time that can be set by the driver, three stages of long, medium and short are prepared as follows.

[0013] Long: 2.4 (sec) Medium: 2.0 (sec) Short: 1.8 (sec) When the vehicle is running at 80 km / h, the time between each vehicle is represented by a distance. Length is about 55m, inside is about 45
m and short are about 40 m. These inter-vehicle times are
It is displayed on the display 40 so that it is possible to see at a glance which inter-vehicle time is currently set.

FIG. 2 shows the configuration of the laser radar 10. The light emitting circuit 10b pulse-drives the laser diode LD10c based on a command from the CPU 10a. The pulse laser light from the laser diode LD10c is shaped by the lens 10d, reflected by the mirror 10e, and enters the polygon mirror f. The polygon mirror has six surfaces and rotates around a rotation axis. The rotation of the polygon mirror 10f scans a pulse laser beam in a horizontal plane (in the horizontal direction with respect to the traveling direction). Further, each surface of the polygon mirror 10f has a different inclination angle sequentially, and scans the pulse laser light in the vertical direction with respect to the traveling direction each time the incident surface of the pulse laser light changes.

On the other hand, when there is a preceding vehicle, the pulse laser light reflected by the preceding vehicle is incident on the photodiode 10h via the light receiving lens 10g, converted into an electric signal, and supplied to the light receiving circuit 10i. The received light pulse signal is further supplied to a time measurement IC 10j, and the time from when the pulse laser light is transmitted to the time when it is reflected and received by the preceding vehicle is measured, and supplied to the CPU 10a to detect the distance to the preceding vehicle. And a relative speed as a time change is detected. The detected inter-vehicle distance and relative speed are supplied to the CPU 10k, and the CPU 10k supplies these detection data to the inter-vehicle control ECU 12.

FIG. 3 schematically shows a scan range 100 of the laser radar 10. Polygon mirror 10
The pulsed laser light scans in a horizontal plane in a horizontal direction with respect to the traveling direction by being reflected on one of the six reflecting surfaces f. Also, the polygon mirror 10
By scanning off the other reflecting surface of f, scanning is performed in the horizontal direction in a different horizontal plane. The pulsed laser light in the vertical direction has a total of 6 corresponding to each of the reflection surfaces of the polygon mirror.
There are a total of 105 books in the left-right direction corresponding to the rotation angle in one reflection surface. The reach of the laser beam is about 100 m in fine weather. Therefore, if there is a preceding vehicle within 100 m, there is a preceding vehicle, and if it is more than 100 m, there is no preceding vehicle.

FIG. 4 is a layout diagram of the vicinity of the steering wheel 50 in the vehicle interior. A lever-shaped cruise control switch 18 is provided on the right side of the steering shaft, and an inter-vehicle time switch 44 is provided on the steering wheel 50. As described above, the cruise control switch 18 has a function to set ON / OFF of the cruise function, a vehicle speed at the time of constant speed running (when no preceding vehicle is present) and an upper limit vehicle speed at the time of following running, and acceleration / deceleration without using the accelerator pedal. It has a function to perform, a resume function to return from the control non-operation state to the operation state, and the like. The inter-vehicle time changeover switch switches a target inter-vehicle time during follow-up traveling (in this embodiment, three stages of long, medium, and short) Have.

FIG. 5 is an enlarged view of the cruise control switch 18. The cruise control switch 18 is in the form of a lever and can be operated up and down. A main switch 18a which can be pushed (in the direction of arrow a in the figure) is provided on the side. By depressing the main switch 18a, the engine ECU 14
Cruise power is turned on. The power ON state is a standby state of the cruise function, and the driver shifts to the actual cruise function when the driver sets the cruise function after the set vehicle speed and the inter-vehicle time are set. The setting of the cruise function (SET) is executed by lowering the cruise control switch 18. As described above, even when the main switch 18a is pressed, the cruise power is not turned on but remains off during the ECT snow mode or the wiper operation. Further, when it is desired to increase the set vehicle speed, the cruise control switch is kept up, and when it is desired to decrease the set vehicle speed, the cruise control switch is kept down.
These data are supplied to U14. When the driver performs an accelerator pedal operation or a brake pedal operation during the control operation, that is, during the cruise function, the control is not operated (the cruise function is canceled). In this state, the operation of raising the cruise control switch 18 is performed. Returns to the original control state (resume function).

FIG. 6 is an enlarged view of the inter-vehicle time changeover switch 44. The inter-vehicle time switch 44 is composed of three switches, a mode (MODE) switch 44a for switching the inter-vehicle time in three stages, and a display 4
Function switch 44 for switching 0 (FUNCTION)
b and a reset switch. The inter-vehicle time is always set to be long in the initial state of the engine ON, and is switched from long to middle and further short by operating the mode switch 44a. When the vehicle becomes shorter and further operations are performed, the inter-vehicle time returns to a longer time. The reason why the inter-vehicle time is uniformly initialized in the initial state when the engine is ON is to ensure the safety when the vehicle shifts to the following running.
The function switch 44b is for switching between a cruise state display and other displays (for example, an alarm display) on the display 40, and the engine E is turned on during cruise control.
The CU 14 displays the control state (presence / absence of a preceding vehicle and a set vehicle speed). When the driver operates the switch 44b, the display changes to a warning display screen or a drive monitor screen. However, if any change occurs in the cruise state (for example, whether the preceding vehicle is detected or the set vehicle speed changes) while the warning display screen is displayed, the display is automatically switched from the warning screen to the cruise state screen. Switch to

FIG. 7 shows a display example of the meter display 40. The speed is displayed on the center left side, the engine speed is displayed on the center right side, and the cruise state screen 41 is displayed on the lower part. This screen 41 can be composed of, for example, liquid crystal. An alarm lamp 42 is provided on the left side of the cruise status screen 41, and a cruise power lamp 43 is further provided on the right side.
Is provided. On the cruise state screen 41, the detected preceding vehicle, target inter-vehicle time, own vehicle, and set vehicle speed are displayed. As described above, when the driver operates the function switch 44b of the inter-vehicle time changeover switch 44, this screen is switched to another screen (warning screen or drive monitor screen). In addition, in order to adjust so that the inter-vehicle time is increased when the tail lamp is lit, it is also preferable that when the tail lamp is lit, the screen 41 has a screen color different from the daytime to notify the driver that the inter-vehicle time is adjusted to be increased. is there. If the vehicle approaches the preceding vehicle abnormally while following the preceding vehicle, a warning is given to the driver using the warning buzzer 32 of the VSC. At this time, the engine ECU 14 displays the screen 41 so as to repeat the inversion of light and dark. It is also preferred to control and visually alert the driver.

The alarm lamp 42 is lit when an abnormality occurs in the cruise function. In this case, the engine ECU 14 cancels the cruise function and displays the details of the abnormality on the screen 41. Of course, the alarm buzzer 32
A warning sound can be used to notify the driver. As the warning sound, for example, a "pawn" or the like can be considered to distinguish it from the warning sound "pipipipi" at the time of following the preceding vehicle.

The configuration of the present embodiment is as described above, and the operation will be described in more detail below.

FIG. 8 shows a flowchart of the cruise control process executed by the headway control ECU 12 and the engine ECU 14. When the driver sets the cruise function using the cruise control switch 18 (turns the main switch ON and sets the switch 18 down), the engine ECU 14 determines whether or not the cruise function has been canceled (S101). If the vehicle has not been cancelled, the following control ECU 12 determines whether or not a preceding vehicle has been detected, and if there is a preceding vehicle, the following control ECU 12 and the engine ECU 14 execute the following cruise control (S103). ). If there is no preceding vehicle, the engine ECU 14 compares the current vehicle speed Vn with the set vehicle speed Vm (S104) and determines that Vn <
If it is Vm, acceleration control is performed to set the vehicle speed (S10
5) If the current vehicle speed Vn is substantially equal to the set vehicle speed Vm, a constant speed cruise control for maintaining the current vehicle speed is executed (S106). If the wiper is activated in rainy weather or EC
When shifting to the snow mode of T, when the driver operates the cruise control switch 18 to cancel, when the driver operates the brake, when the vehicle speed falls below a predetermined value (for example, 40 km / h), the cruise function is activated. If an abnormality occurs, for example, YES is determined in S101, and the engine ECU 14 cancels the cruise function (S107).

FIG. 9 shows a detailed flowchart of the inter-vehicle cruise executed in S103. First, the laser radar 10 detects the inter-vehicle distance and the relative speed with the preceding vehicle (S201), and the inter-vehicle control ECU 12 calculates the inter-vehicle deviation between the target inter-vehicle time and the current inter-vehicle time (S202).
Then, the control acceleration (target acceleration) required to reduce the inter-vehicle deviation to zero is calculated (S203), and the engine E
Supply to CU14. The engine ECU 14 controls the electronic throttle actuator 24 to obtain this control acceleration.
Is driven to control the engine output (S204). If the calculated control acceleration is a large negative value, that is, a large deceleration side, the engine ECU 14 cuts overdrive, shifts down, and decelerates with engine brake.

FIG. 10 schematically shows the above processing contents. (A) shows a case where there is no preceding vehicle (100
m, and the vehicle runs at a constant speed at the vehicle speed set by the driver (S106 in FIG. 8).
Constant speed cruise in). (B) is a case where a preceding vehicle that is slower than the set vehicle speed is detected during traveling at a constant speed, and deceleration control is performed so as not to abnormally approach the preceding vehicle (inter-vehicle cruise in S103 in FIG. 8). (C) is a case where the vehicle follows the preceding vehicle, and acceleration / deceleration control is performed such that the inter-vehicle time with the preceding vehicle becomes the target inter-vehicle time with the set vehicle speed as an upper limit (S103 in FIG. 8).
Cruise between vehicles in). (D) is a case where the preceding vehicle has entered the interchange or the service area and is no longer present. In this case, the vehicle gradually accelerates to the set vehicle speed (constant speed cruise in S106 in FIG. 8). In addition, when the preceding vehicle disappears, the vehicle gradually accelerates to the set vehicle speed, as described above, when the preceding vehicle disappears due to the vehicle entering the rampway or the service area, the vehicle speed is gradually increased to the set vehicle speed. The sudden acceleration takes into account the undesirable effects.

On the other hand, some drivers may want to quickly shift to constant speed running at a set vehicle speed when a preceding vehicle enters an interchange or a service area. In particular, on a congested road, it is desirable that a sufficient acceleration can be obtained because the following vehicle suddenly approaches. In such a case, the driver can obtain a desired acceleration by depressing the accelerator pedal, but it is not appropriate to force the driver to operate the accelerator pedal during the cruise function. Is preferably obtained.

Therefore, in the present embodiment, the cruise control switch 18 having the resume function is also functioned as operating means for quick acceleration. That is, when the preceding vehicle disappears and the vehicle shifts from the following running to the constant speed running, the engine ECU 14 normally accelerates the own vehicle gradually, but when the driver operates the cruise control switch 18 upward, the engine ECU 14 In response to this command, the own vehicle is accelerated with a larger acceleration to reach the set vehicle speed. As a result, the driver can quickly shift to the constant speed running at the set vehicle speed without separately depressing the accelerator pedal.

FIG. 11 is a flowchart showing the processing of the engine ECU 14 in the present embodiment. First, it is determined whether or not a preceding vehicle exists (S301). If there is, a target acceleration / deceleration is calculated (S308).
The inter-vehicle control (follow-up running) is executed (S309). If there is no preceding vehicle in this state, it is next determined whether or not the current vehicle speed is lower than the set vehicle speed (set vehicle speed) (S3).
02). If the current vehicle speed has already reached the set vehicle speed, the vehicle travels at a constant speed at the set vehicle speed (S307). However, if the current vehicle speed is lower than the set vehicle speed, the driver performs a resume operation before calculating the target acceleration. Whether the driver has cruise control switch 1
Then, it is determined whether or not 8 has been operated upward (S303). When the driver has not performed the resume operation, the normal low acceleration α1 at the time of shifting from the following running to the constant speed running is set as the target acceleration (S304). Is the target acceleration (S305). Then, the vehicle is accelerated to the set vehicle speed with these accelerations (S306).

When a preceding vehicle that is slower than the own vehicle is detected during traveling at a constant speed, deceleration control is performed until the target inter-vehicle time is reached. In this case, the target acceleration calculated by the inter-vehicle control ECU 12 is negative. Therefore, the engine ECU 14 immediately shifts down and starts deceleration control.

As described above, in the present embodiment, an acceleration greater than usual can be obtained with the operation switch at hand, so that even if the preceding vehicle disappears and the following vehicle approaches, the own vehicle can be easily accelerated. It becomes possible. Further, since the hand operation switch also serves as the resume function, the driver can naturally perform this operation in the sense of returning to the original large acceleration. Further, by performing the operation of the hand operation switch a plurality of times, multi-stage acceleration setting may be performed.

In the above-described embodiment, the cruise control switch 18 is used as the hand operation means, but any hand operation switch can be used. Alternatively, a sufficiently large acceleration may be obtained by separately providing an acceleration switch and operating the acceleration switch. However, since the addition of a new switch complicates the device configuration, it is preferable to use the switch with an existing operation switch.

[0032]

As described above, according to the present invention,
It is possible to quickly shift to constant speed running at the set vehicle speed with the operating means at hand while maintaining safety at the time of shifting from following running to constant speed running, and it is also possible to easily secure the headway with the following vehicle it can.

[Brief description of the drawings]

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

FIG. 2 is a configuration diagram of a laser radar according to the embodiment.

FIG. 3 is an explanatory diagram of a scan range of the laser radar according to the embodiment.

FIG. 4 is an explanatory view of an arrangement in the vicinity of a steering according to the embodiment;

FIG. 5 is an enlarged view of the cruise control switch of the embodiment.

FIG. 6 is an enlarged view of an inter-vehicle time switch according to the embodiment;

FIG. 7 is an explanatory diagram of a display according to the embodiment.

FIG. 8 is an overall processing flowchart of the embodiment.

FIG. 9 is an inter-vehicle control flowchart of the embodiment.

FIG. 10 is an explanatory diagram illustrating a processing mode according to the embodiment;

FIG. 11 is a flowchart of acceleration control at the time of transition from follow-up traveling to constant-speed traveling in the embodiment.

[Explanation of symbols]

10 laser radar, 12 inter-vehicle control ECU, 14 engine ECU, 16 ECT mode switch, 18 cruise control switch (hand operation means), 20 stop lamp switch, 22 vehicle speed sensor, 24 electronic throttle actuator, 26 ECT solenoid,
28 VSC-ECU, 30 steering sensor, 3
2 Alarm buzzer, 34 body multiplex communication, 36 tail lamp switch, 38 wiper switch, 40 display, 44 inter-vehicle time switch.

 ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Nobuyuki Furui 1 Toyota Town, Toyota City, Aichi Prefecture Inside Toyota Motor Co., Ltd. (72) Inventor Yasuhiko 1-1-1-1 Showacho, Kariya City, Aichi Prefecture DENSO Corporation (72) Inventor Eiji Teramura 1-1-1, Showa-cho, Kariya-shi, Aichi Prefecture Inside DENSO Corporation

Claims (2)

[Claims] 1. A control device for following a vehicle when a preceding vehicle is present and traveling at a constant speed at a set vehicle speed when there is no preceding vehicle, comprising: a hand operating means; Control means for increasing the speed of the own vehicle to the set vehicle speed at an acceleration equal to or higher than the non-operation when the operation means is operated at the time of shifting. 2. The vehicle travel control device according to claim 1, wherein said hand operation means also functions as a resume switch for returning from a control non-operation state to an operation state.