JP2005145403A - Vehicle following distance control device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To safely execute vehicle distance control without stopping it even under rain weather or the like in a vehicle following distance control device. <P>SOLUTION: This vehicle following distance control device controls car speed Vs of a vehicle 100 to keep vehicle following distance D to a preceding vehicle at a prescribed value based on the vehicle following distance D measured by vehicle following distance measuring means 11 and 12 to measure the vehicle following distance to the preceding vehicle. It is provided with rain fall detecting means 12-15 to detect rain fall, and a control means to determine rain fall state correlation parameter ε based on information from the rain fall detecting means 12-15, determine measurable distance Dc by the vehicle following distance measuring means 11 and 12 based on the parameter ε from a predetermined map, and control the car speed Vs of the vehicle 100 under assumption that a supposed preceding vehicle 101 exists at the same speed as the vehicle 100 at the position of the measurable distance Dc. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  According to the present invention, based on the inter-vehicle distance measured by the inter-vehicle distance measuring means for measuring the inter-vehicle distance from the preceding vehicle, the inter-vehicle distance for controlling the vehicle speed of the host vehicle so that the inter-vehicle distance is set to a predetermined value. The present invention relates to a distance control device.

  In recent years, an inter-vehicle distance control device that performs tracking traveling control of a preceding vehicle has been developed in order to reduce driving operations of an automobile. This inter-vehicle distance control device obtains an appropriate target inter-vehicle distance from the vehicle speed of the host vehicle at that time by setting an operation switch, for example, and information from inter-vehicle distance measuring means such as a CCD camera or a laser radar Measure the inter-vehicle distance between the host vehicle and the preceding vehicle based on the above, and control the engine output, brakes, etc. so that this inter-vehicle distance becomes the target inter-vehicle distance, and follow the preceding vehicle Can be done.

  By the way, CCD cameras and laser radars usually have a ranging performance (about 100 m or more) that can secure a sufficient vehicle interval, but when it rains, raindrops, etc. Since the obstacle exists, the distance measurement performance is greatly deteriorated. For this reason, in the conventional inter-vehicle distance control device, the inter-vehicle distance control is stopped when the ranging performance of the CCD camera or the laser radar is significantly reduced due to rain or the like (for example, Patent Documents 1 and 2 below) reference).

Japanese Patent Laid-Open No. 10-081156 Japanese Patent Laid-Open No. 11-034693

  However, in the inter-vehicle distance control device as described above, it has been strongly demanded that the inter-vehicle distance control can be performed safely without stopping even in rainy weather.

  The inter-vehicle distance control device according to the first invention for solving the above-described problem is based on the inter-vehicle distance with the preceding vehicle measured by the inter-vehicle distance measuring means for measuring the inter-vehicle distance with the preceding vehicle. In the inter-vehicle distance control device that controls the speed of the host vehicle so that the inter-vehicle distance is a predetermined value, the rain detection unit that detects the rain, and the rain state correlation parameter ε is calculated based on the information from the rain detection unit When the rain condition correlation parameter ε is equal to or greater than the threshold value α, the measurable distance Dc by the inter-vehicle distance measuring means is obtained from a predetermined map based on the rain condition correlation parameter ε, and the measurable distance Assuming that a temporary preceding vehicle having the same speed as that of the host vehicle exists at the position of Dc, a control means for controlling the vehicle speed of the host vehicle is provided.

  The inter-vehicle distance control device according to a second aspect of the present invention is based on the first aspect of the invention, when the control means is based on the rain condition correlation parameter ε when the rain condition correlation parameter ε is greater than or equal to the threshold value α. Further, a necessary inter-vehicle time Tn required for the temporary preceding vehicle is obtained from a predetermined map, a target vehicle speed Vt is calculated based on the measurable distance Dc and the necessary inter-vehicle time Tn, and the target vehicle speed The vehicle speed of the host vehicle is controlled so as to be Vt.

  The inter-vehicle distance control device according to a third aspect of the present invention is the first or second aspect of the present invention, wherein the control means is configured such that when the rainfall state correlation parameter ε is smaller than the threshold value α, the vehicle is in normal mode. It is characterized by controlling the speed.

  According to the inter-vehicle distance control device according to the first aspect of the present invention, it is possible to safely carry out inter-vehicle distance control without stopping even in rainy weather.

  According to the inter-vehicle distance control device according to the second aspect of the invention, the effect of the first aspect of the invention can be obtained with certainty.

  According to the inter-vehicle distance control device according to the third aspect of the invention, it is possible to automatically switch between the fine weather mode and the wet weather mode, and the ease of operation can be improved.

  An embodiment of an inter-vehicle distance control device according to the present invention will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram of the inter-vehicle distance control device, FIG. 2 is a control flowchart of the inter-vehicle distance control device, and FIG. 3 is an operation explanatory diagram of the inter-vehicle distance control device.

  As shown in FIG. 1, a scanning laser radar 11 that recognizes an object or the like by emitting a laser beam forward while scanning is provided at the front of the vehicle 1. A CCD camera 12 that images the front of the vehicle 1 is provided on the roof portion of the vehicle 1. The CCD camera 12 can recognize not only an object located in front but also a lane (white line). On the bonnet located at the upper part of the engine 2, a rain sensor 13 for detecting rain by detecting the pressure of raindrops is provided.

  The steering column 4 of the steering wheel 3 is provided with a wiper switch 14 for performing an operation switching operation of a windshield (windscreen) wiper 5. A wheel speed sensor 15 is provided on each of the left and right sides of the rear wheel 6 so that the right wheel speed Vsr and the left wheel speed Vsl can be detected. Further, the steering column 4 is provided with a handle angle sensor 16 that detects the handle angle θH from the rotation angle of the steering wheel 3.

  On the other hand, a throttle actuator 21 that opens and closes the throttle valve 7 is provided in the throttle valve 7 that adjusts the engine output by controlling the intake amount to the engine 2 by changing the opening degree. The hydraulic control unit 9 that performs shift switching of the automatic transmission (A / T) 8 connected to the output shaft side of the engine 2 includes an A / T controller 22 that performs switching operation of a solenoid valve (not shown) of the hydraulic control unit 9. Is provided.

  The brake pedal 10 for operating a service brake (not shown) such as a hydraulic disc brake provided on the front and rear wheels 6 is provided with a brake actuator 23 for operating the brake pedal 10 or a brake master cylinder (not shown).

  The laser radar 11, the CCD camera 12, the rain sensor 13, the wiper switch 14, the wheel speed sensor 15, and the handle angle sensor 16 are electrically connected to an input unit of an electronic control unit (ECU) 30 serving as control means. . On the other hand, the throttle actuator 21, the A / T controller 22, and the brake actuator 23 are electrically connected to the output unit of the ECU 30.

  Further, an auto cruise operation switch 17 for switching the operation of the inter-vehicle distance control device (auto cruise controller) of the vehicle 1 is electrically connected to the input portion of the ECU 30, and the output of the ECU 30 is controlled by the auto cruise controller. A display 24 for displaying the state is electrically connected, and the ECU 30 controls the engine output and brakes by controlling the travel adjusting devices 21 to 23 based on information from the information devices 11 to 17. Is supposed to do.

  Specifically, in the auto cruise controller, when the auto cruise operation switch 17 is operated to the set side, as shown in FIG. 2, the ECU 30 becomes the rain detection means, the laser radar 11, the CCD camera 12, Based on information from the rain sensor 13, the wiper switch 14, and the wheel speed sensor 15, a rain state correlation parameter ε is calculated (step S1) (more specifically, Japanese Patent Laid-Open No. 10-138792 [0033] to [0038]. reference).

  Next, the ECU 30 compares the parameter ε with a preset threshold value α (step S2). If the parameter ε is smaller than the threshold value α, the ECU 30 determines normal mode control (step S3). Based on information from the laser radar 11, the CCD camera 12, and the handle angle sensor 16, an inter-vehicle distance D with a preceding vehicle traveling on the same traveling lane is calculated, and the inter-vehicle distance D and information from the wheel speed sensor 15 are calculated. Based on the (vehicle speed Vs), the throttle actuator 21, the A / T controller 22 and the brake actuator 23 are controlled so that the target inter-vehicle distance Dt is set in advance according to the vehicle speed Vs, and the engine output and the brake Control is performed (for more details, refer to JP-A-10-138792 [0018] to [0031], etc.). Accordingly, the vehicle speed Vs of the host vehicle is controlled so that the inter-vehicle distance D with the preceding vehicle traveling in the same travel lane as the host vehicle is set as the target inter-vehicle distance Dt.

  If the parameter ε is greater than or equal to the threshold value α, the ECU 30 determines that the control mode is raining, and a laser radar that is an inter-vehicle distance measuring means from a map set in advance according to the magnitude of the parameter ε. 11 and the distance Dc measurable by the CCD camera 12 and the necessary inter-vehicle time Tn are obtained (step S4).

  Subsequently, the ECU 30 calculates a target vehicle speed Vt from the measurable distance Dc and the necessary inter-vehicle time Tn based on an equation (Vt = Dc / Tn) (step S5). Specifically, for example, when the measurable distance Dc obtained in step S4 from the parameter ε is 40 m and the required inter-vehicle time Tn is 2 seconds, the target vehicle speed Vt is 20 m / s (= 72 km / h).

  Then, the ECU 30 controls the engine output and the brake by controlling the throttle actuator 21, the A / T controller 22 and the brake actuator 23 so that the current vehicle speed Vs becomes the target vehicle speed Vt. Control the vehicle speed. (Step S6).

  That is, in this embodiment, as shown in FIG. 3, when the distance measurement performance of the inter-vehicle distance measuring means such as the laser radar 11 and the CCD camera 12 deteriorates due to rain or the like, the inter-vehicle distance measurement is performed based on the parameter ε. The measurable distance Dc corresponding to the rain state of the means is obtained from a predetermined map, and a preceding vehicle having the same speed as the vehicle speed Vs (for example, 80 km / h) of the host vehicle 100 is located at the position of the measurable distance (for example, 40 m). Assuming that it exists, an inter-vehicle distance (measurable distance Dc = 40 m) from the temporary preceding vehicle 101 is set, and a necessary inter-vehicle time Tn (necessary to the temporary preceding vehicle 101 based on the parameter ε ( For example, 2 seconds) is obtained from a predetermined map, and based on the inter-vehicle distance (40 m) and the inter-vehicle time (2 seconds), a vehicle speed (target vehicle speed Vt = The vehicle speed Vs of the host vehicle 100 is controlled by performing engine output and brake control so that Dc / Tn = 72 km / h).

  Thus, in the present embodiment, the inter-vehicle distance control is continued without being interrupted even in rainy weather.

  The actual preceding vehicle 102 exists within the measurable distance Dc, such as a preceding vehicle having a slower traveling speed than the own vehicle 100 or a preceding vehicle that has changed its course ahead of the traveling lane of the own vehicle 100. Then, the actual vehicle distance D (for example, 30 m) from the actual preceding vehicle 102 is measured, and a new vehicle speed that can ensure safety based on the vehicle distance D and the vehicle time Tn. The engine output and the brake control are performed so that (target vehicle speed Vt = D / Tn = 54 km / h), and the vehicle speed Vs of the host vehicle 100 is controlled.

  Therefore, according to this embodiment, even when it is raining, it can be safely performed without stopping the inter-vehicle distance control.

  The inter-vehicle distance control device according to the present invention can be used very effectively in the automobile industry.

It is a schematic block diagram of embodiment of the inter-vehicle distance control apparatus which concerns on this invention. It is a control flowchart of embodiment of the inter-vehicle distance control apparatus which concerns on this invention. It is operation | movement explanatory drawing of embodiment of the inter-vehicle distance control apparatus which concerns on this invention.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Vehicle 2 Engine 3 Steering wheel 4 Steering column 5 Wiper 6 Wheel 7 Throttle valve 8 Automatic transmission 9 Hydraulic control unit 10 Brake pedal 11 Laser radar 12 CCD camera 13 Rain sensor 14 Wiper switch 15 Wheel sensor 16 Handle angle switch 17 Operation switch 21 Throttle actuator 22 A / T controller 23 Brake actuator 24 Display 30 Electronic control unit (ECU)
100 own vehicle 101 provisional preceding vehicle 102 actual preceding vehicle

Claims (3)

In the inter-vehicle distance control device for controlling the vehicle speed of the host vehicle so that the inter-vehicle distance is set to a predetermined value based on the inter-vehicle distance measured by the inter-vehicle distance measuring means for measuring the inter-vehicle distance with the preceding vehicle. ,
Rain detection means for detecting rainfall;
Based on the information from the rain detection means, a rain state correlation parameter ε is calculated. When the rain state correlation parameter ε is equal to or greater than a threshold value α, the inter-vehicle distance measurement means is based on the rain state correlation parameter ε. And a control means for controlling the vehicle speed of the host vehicle assuming that a temporary preceding vehicle having the same speed as the host vehicle is present at the position of the measurable distance Dc. An inter-vehicle distance control device. In claim 1,
When the rain condition correlation parameter ε is equal to or greater than the threshold value α, the control means further determines a necessary inter-vehicle time Tn necessary for the temporary preceding vehicle based on the rain condition correlation parameter ε. A target vehicle speed Vt is calculated based on the measurable distance Dc and the necessary inter-vehicle time Tn, and the vehicle speed of the host vehicle is controlled so as to be the target vehicle speed Vt. apparatus. In claim 1 or claim 2,
The inter-vehicle distance control device, wherein the control means controls the speed of the host vehicle in a normal mode when the rainfall state correlation parameter ε is smaller than the threshold value α.

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