JP4214954B2 - Inter-vehicle distance control device - Google Patents

Description

  The present invention relates to an inter-vehicle distance control device that controls an inter-vehicle distance with a preceding vehicle ahead of the host vehicle.

2. Description of the Related Art Conventionally, an inter-vehicle distance control device that varies a start condition or a release condition of inter-vehicle distance control is known (see, for example, Patent Document 1). This inter-vehicle distance control device reduces the driver's uncomfortable feeling that occurs at the time of switching control by varying the start or release conditions of inter-vehicle distance control in accordance with the running state.
Japanese Patent Laid-Open No. 10-181382

  By the way, in the system aiming at reducing the driving load of the driver, such as the inter-vehicle distance control system, if there is a possibility that the system falls into an unsupportable state (unsupportable condition), or if it falls, a warning sound is promptly sent to the driver. It is necessary to notify the driver by voice or voice, etc. and encourage the driver to drive himself. However, when the driver puts the system into operation, if the driver was in an unsupportable condition in the first place, the system immediately determines that it cannot support driving, and responds to the driver by driving a warning sound. Will do. Taking the case of the inter-vehicle distance control device as an example, when a person drives, the inter-vehicle distance is often narrower than the inter-vehicle distance targeted by the inter-vehicle distance control device. At that time, even if the inter-vehicle distance control device is operated, a warning sound is generated as driving assistance cannot be performed at the current inter-vehicle distance.

  In other words, even though the driver wants to leave the driving operation to the system and activates the system, as a result, the driver cannot leave the driving operation to the system. Therefore, not only the intention of the driver is not reflected in the system, but also the question of the system as to when the driving operation can be entrusted or the distrust of the system arises.

  Furthermore, similar problems may occur not only when trying to start the system, but also when the system is running. For example, during execution of the inter-vehicle distance control, if the driver wants to reduce the inter-vehicle distance a little, the driver can operate the accelerator himself and approach the preceding vehicle. However, when the inter-vehicle distance is reduced by the driver's accelerator operation, it may correspond to a support disabling condition of the inter-vehicle distance control device (for example, support is not possible when the inter-vehicle distance is 5 m or less). As a result, the inter-vehicle distance control device sounds a warning sound, which makes the driver feel uncomfortable.

  It can be considered that an inter-vehicle distance control device that makes the start condition and the release condition variable according to the traveling state as an effective solution to the above problem. However, since the determination conditions of the inter-vehicle distance control device of the prior art are varied based on the actual traveling state such as the inter-vehicle distance and the vehicle speed, the determination condition for the actual traveling state is uniquely determined once the actual traveling state is determined. Become. In other words, when the driver performs some kind of intervention operation on the inter-vehicle distance control device, such as the above problem, depending on the determination conditions determined according to the driving state at that time, the control operation may be different from the driver's intention. Has been made.

  Therefore, an object of the present invention is to provide an inter-vehicle distance control device that performs a control operation that does not give the driver a sense of incongruity even when the driver performs an intervention operation.

In order to solve the above problems, according to one aspect of the present invention,
A determination means for determining whether or not the traveling state of the host vehicle corresponds to an unsupportable condition for determining a vehicle traveling state in which driving support by inter-vehicle distance control is impossible;
In the inter-vehicle distance control device comprising the inter-vehicle distance control stop unit that does not start or execute the inter-vehicle distance control when the determination unit determines that the support disable condition is satisfied,
The unsupportable condition is relaxed to the supportable side from the normal unsupportable condition during a period in which a request for starting the inter-vehicle distance control by the driver is received, and during the inter-vehicle distance control started after the start request, There is provided an inter-vehicle distance control device that returns to an unsupportable condition . Thereby, even if the driver performs an intervention operation on the inter-vehicle distance control device, it is possible to suppress the determination that the inter-vehicle distance control device cannot be supported by relaxing the unsupportable condition to the supportable side.

  In addition, when there is a request for starting the inter-vehicle distance control by the driver before the start of the inter-vehicle distance control, it is preferable that the unsupportable condition is relaxed to the supportable side. Thereby, during the non-control before the start of the inter-vehicle distance control, it is possible to relax the determination of the unsupportable condition and to easily start the control. Furthermore, even if the vehicle running condition corresponds to the normal support impossible condition at the time when the control start request is made, by making the determination of the support impossible condition loose, a warning sound or the like sounds and the driver himself operates. It is possible to suppress being responded to.

  It should be noted that when this start request is issued, it is possible to relax the inability to support conditions more than normal inter-vehicle distance control because the driver's forward attention is not yet reduced at the time when the start request is made. Because it can be expected.

  Moreover, it is preferable that the unsupportable condition is relaxed to the supportable side when the driver performs an accelerator operation during the execution period of the inter-vehicle distance control. As a result, the distance between the vehicles is reduced by the accelerator operation by the driver, and whenever a support impossible condition (for example, driving support is not possible when the distance between vehicles is 5 m or less) is suppressed, notification by a warning sound or the like is further suppressed. Can make the driver uncomfortable.

  In the case of this accelerator operation, the unsupportable condition can be relaxed compared to the normal inter-vehicle distance control. When the driver performs the accelerator operation himself, the driver intends to drive himself. Because we can expect that.

  Moreover, it is preferable that the relaxation to the supportable side of the unsupportable condition is maintained for a predetermined time. Thereby, in the state controlled by the inter-vehicle distance control device after the input operation by the driver, it is possible to prevent the support failure condition from being met again.

  According to the present invention, even when the driver performs an intervention operation, it is possible to perform a control operation without causing the driver to feel uncomfortable.

  The best mode for carrying out the present invention will be described below with reference to the drawings. FIG. 1 shows a configuration diagram of an inter-vehicle distance control system which is an embodiment of the inter-vehicle distance control device of the present invention. The inter-vehicle distance control apparatus according to the present embodiment includes, for example, a laser radar 12 that irradiates an irradiation beam in front of the vehicle, a wheel speed sensor 14 that detects the vehicle speed of the host vehicle, an electronic control unit (hereinafter referred to as an ECU), and the like. The Examples of the electronic control ECU include an inter-vehicle control ECU 1, an engine ECU 2, and a brake ECU 3.

  For example, a laser radar 12 disposed on a bumper or a front grille is connected to the inter-vehicle control ECU 1. The laser radar 12 includes a light emitting unit that irradiates a laser having a microwave as a carrier wave in front of the vehicle, and a light receiving unit that receives a reflected wave related to the laser irradiated in front of the vehicle. The laser radar 12 is configured to scan a predetermined range in front of the vehicle at a predetermined cycle. The laser radar 12 outputs a signal or the like corresponding to the time until the reflected wave reflected by the preceding vehicle is received by the light receiving unit to the determination unit 5 in the inter-vehicle control ECU 1 after the laser is emitted from the light emitting unit. To do.

The judging means 5 derives the inter-vehicle distance L to the preceding vehicle existing within a predetermined range based on the output signal of the laser radar 12, and differentiates the detected inter-vehicle distance L to differentiate the host vehicle and the preceding vehicle. Relative speed V _r (the speed of the host vehicle with respect to the preceding vehicle) is derived.

A wheel speed sensor 14 is also connected to the inter-vehicle control ECU 1. The wheel speed sensor 14 outputs a pulse signal to the determination means 5 in the inter-vehicle control ECU 1 at a cycle corresponding to the speed of the host vehicle. The determination means 5 derives the speed of the host vehicle (hereinafter referred to as the vehicle speed V ₁ ) based on the output signal of the wheel speed sensor 14. The determination means 5 derives the speed V _{2 of the} object based on the relationship between the detected vehicle speed V ₁ and the relative speed V _r between the host vehicle and the object.

  A G sensor 13 may also be connected to the inter-vehicle control ECU 1. The G sensor 13 detects the acceleration of the host vehicle and outputs the detected value to the inter-vehicle control ECU 1. Further, information such as an ABS operation signal, a VSC operation signal, and other sensor signals from an ABS (Anti-lock Brake System) ECU, a VSC (Vehicle Stability Control) ECU, or the like may be used for inter-vehicle control.

The determination means 5 recognizes the traveling state of the host vehicle based on the inter-vehicle time, inter-vehicle distance L, relative speed V _r , vehicle speed V _{1 and the} like derived from the output signals of various sensors. Then, it is determined whether or not the recognized traveling state of the host vehicle corresponds to a support disabling condition that determines a vehicle traveling state in which driving support by inter-vehicle distance control is impossible.

  The determination result of the determination unit 5 is output to the inter-vehicle distance control stop unit 8. The inter-vehicle distance control stop means 8 does not start or execute the inter-vehicle distance control when it receives the determination result that the support disable condition is met.

  In addition, the vehicle is provided with notifying means 17 for transmitting various information to the driver. The notification unit 17 is, for example, a combination meter, a sound generation device, a multi display, or the like. For example, a lamp, warning sound or message informs the driver that the inter-vehicle distance control device is in a state where follow-up control is possible, the preceding vehicle may stop, or the inter-vehicle distance cannot be measured. is there. When it is determined by the determination means 5 that the support disabling condition is met, the notification means 17 notifies the driver that the driving support by the inter-vehicle distance control device is impossible together with a warning sound so that the driver can perform the driving operation himself. Prompt.

  The vehicle is also provided with a brake device that brakes each wheel. The brake device has a brake actuator 16 that generates a braking force on each wheel. The brake actuator 16 is electrically connected to the brake ECU 3 and generates a braking force according to a command signal (target hydraulic pressure or the like) commanded from the brake ECU 3 on each wheel.

  A throttle valve is disposed in the intake pipe connected to the internal combustion engine. A throttle motor as an actuator is connected to the throttle valve. This throttle motor is driven and controlled in accordance with a command from the engine ECU 2 to adjust the opening of the throttle valve. The throttle valve is adjusted to an opening degree corresponding to the drive of the throttle motor as the electronic throttle 15 to adjust the amount of air supplied to the internal combustion engine.

  These engine ECU 2 and brake ECU 3 receive a control signal from an inter-vehicle distance control means (not shown) in the inter-vehicle control ECU 1 and control the electronic throttle 15 and the brake actuator 16. Note that the ECUs exemplified above including the inter-vehicle control ECU 1 store, for example, a CPU that executes a program for executing control, and those programs, and temporarily stores the calculation results of the programs. Storage means including a ROM, a RAM, and the like. For example, the determination unit 5 and the inter-vehicle distance control stop unit 8 may be realized by this program.

  Next, an embodiment of the inter-vehicle distance control device according to the present invention will be described with reference to FIGS. First, the first embodiment will be described. FIG. 2 is a diagram illustrating the relationship between the determination threshold gain and the time for the support disabling determination condition before and after the inter-vehicle distance control start request by the driver. For example, it is assumed that the support disabling condition is “a distance between vehicles of 5 m or less”. By defining in this way, if the judging means 5 in the inter-vehicle control ECU 1 judges that the inter-vehicle distance between the host vehicle and the preceding vehicle is 5 m or less and falls under the support disabling condition, the inter-vehicle distance control stopping means 8 The control means does not start or execute the control, and the notification means 17 issues a warning sound to the driver that the driving support is impossible and notifies the driver to perform the driving operation himself.

  When the driver tries to start the inter-vehicle distance control (for example, to turn on the control start switch), if the inter-vehicle distance from the preceding vehicle is already 5 m or less, a warning sound etc. will be notified as soon as the start request is made. In order to suppress this, for example, the determination threshold gain is set to 0.5. That is, in the period (a) in which the inter-vehicle distance control start request from the driver is received, the condition determination is performed with the unsupportable condition as “inter-vehicle distance of 2.5 m or less”. As a result, even if an inter-vehicle distance control start request is made when the actual inter-vehicle distance is 3 m, inter-vehicle distance control can be started without notification of a warning sound or the like. Of course, if the inter-vehicle distance is 2.5 m or less when the inter-vehicle distance control start request is made, a warning sound or the like is notified. Note that the start point of the period (a) may be when the ignition key is ON.

  When the inter-vehicle distance control is started, deceleration control is performed on the inter-vehicle distance control device side so as to be a normal target inter-vehicle distance (in this example, at least a predetermined value of 5 m or more). When the determination threshold gain is returned to 1.0 immediately after the start of the inter-vehicle distance control, it is necessary to prevent the support failure condition from being met during the deceleration control. Therefore, a period (b) is provided (for example, 5 seconds) as the time from when the start of the inter-vehicle distance control is requested until the determination threshold gain returns to the normal 1.0 (for example, 5 seconds). The threshold gain is set to a value smaller than 1.0. In FIG. 2, the determination threshold gain is increased to 1.0 over time, but the determination threshold gain is maintained at 0.5 in the period (b) and then returned to 1.0. May be.

  In the period (c) after the determination threshold gain is returned to 1.0, normal inter-vehicle distance control is performed by setting the support impossible condition to “inter-vehicle distance of 5 m or less”. The period (c) may be until the inter-vehicle distance control ends.

  Next, a case where an accelerator operation is performed by the driver during inter-vehicle distance control will be described as a second embodiment. FIG. 3 is a diagram showing the relationship between the determination threshold gain and time for the support impossibility determination condition before and after the accelerator operation by the driver. Similar to the first embodiment, in the second embodiment, the unsupportable condition is “a distance between vehicles of 5 m or less”.

  During the inter-vehicle distance control by the inter-vehicle distance control device, that is, during the period (d), the determination threshold gain is a normal 1.0. During the execution of the inter-vehicle distance control, the driver can operate the accelerator himself and approach the preceding vehicle if he wants to reduce the inter-vehicle distance. However, every time the inter-vehicle distance is reduced by the driver's accelerator operation and the inter-vehicle distance becomes 5 m or less, a notification by a warning sound or the like will cause the driver to feel uncomfortable. In order to prevent this, the determination threshold gain is set to 0.5 when the driver's accelerator operation is performed. The determination threshold gain 0.5 is maintained until the accelerator operation is completed. In other words, during the period (e) in which the driver performs the accelerator operation, the condition determination is performed with the support impossible condition set to “the distance between the vehicles is 2.5 m or less”.

  When the accelerator operation is completed, deceleration control is performed on the side of the inter-vehicle distance control device so as to be a normal target inter-vehicle distance (in this example, a predetermined value of at least 5 m). For the same reason as in the first embodiment, after the gain return period (f), the normal determination threshold gain is returned to 1.0.

  In the period (g) after the determination threshold gain returns to 1.0, the normal inter-vehicle distance control is performed by setting the incapable support condition to “inter-vehicle distance of 5 m or less”. The period (g) may be until the inter-vehicle distance control ends.

  The preferred embodiments of the present invention have been described in detail above. However, the present invention is not limited to the above-described embodiments, and various modifications and substitutions can be made to the above-described embodiments without departing from the scope of the present invention. Can be added.

  In the above embodiment, the inter-vehicle distance control device has been described. However, the clearance sonar system or the like is intended to reduce the driving load of the driver, and is effective for a system in which the driver can perform an intervention operation even when the system is operating.

It is a figure showing an example of the schematic structure of the vehicle height adjusting device of the present invention. It is the figure which showed the relationship between determination threshold gain and time about the assistance impossibility determination conditions before and behind the distance control start request | requirement by a driver. It is the figure which showed the relationship between determination threshold gain and time about the assistance impossibility determination conditions before and behind the accelerator operation by a driver.

Explanation of symbols

1 Inter-vehicle control ECU
5 Judgment means 8 Inter-vehicle distance control stop means

Claims (4)

A determination means for determining whether or not the traveling state of the host vehicle corresponds to an unsupportable condition for determining a vehicle traveling state in which driving support by inter-vehicle distance control is impossible;
In the inter-vehicle distance control device comprising the inter-vehicle distance control stop unit that does not start or execute the inter-vehicle distance control when the determination unit determines that the support disable condition is satisfied,
The unsupportable condition is relaxed to the supportable side from the normal unsupportable condition during a period in which a request for starting the inter-vehicle distance control by the driver is received, and during the inter-vehicle distance control started after the start request, An inter-vehicle distance control device that returns to an unsupportable condition . The unsupportable condition is relaxed to the supportable side from the normal unsupportable condition when the driver performs an accelerator operation during the execution period of the inter-vehicle distance control. The inter-vehicle distance control device according to claim 1, which returns to a condition .   The inter-vehicle distance control device according to claim 1, wherein the relaxation of the unsupportable condition toward the supportable side is maintained for a predetermined time. It is determined whether the distance between the host vehicle and the preceding vehicle meets the inability to support,
The inter-vehicle distance control device according to any one of claims 1 to 3 , wherein the unsupportable condition is relaxed to a supportable side by reducing the inter-vehicle distance.

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