JP2005145400A - Traveling control device for vehicle - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a traveling control device for a vehicle securely capable of preventing slip even in a case of acceleration/deceleration control under rain. <P>SOLUTION: This traveling control device for a vehicle controls car speed Vs of a vehicle 1 to keep vehicle following distance D to a preceding vehicle traveling in the same traveling lane as the vehicle 1 at a prescribed value. It is provided with rain fall detecting means 11-15 to detect rain fall, and an ECU 30 to determine rain fall state correlation parameter ε based on information from the rain fall detecting means 11-15, determine the maximum tolerable acceleration Amax based on the rain fall state correlation parameter ε and the car speed Vs in a case where the rain fall state correlation parameter ε is the lowest limit value α1 or more and the upper limit value α2 or less, and conduct engine output and brake control not to exceed the maximum tolerable acceleration Amax. <P>COPYRIGHT: (C)2005,JPO&NCIPI

Description

  The present invention relates to a vehicle travel control device.

  In recent years, an inter-vehicle distance control device that performs tracking travel control of a preceding vehicle has been developed as a travel control device 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 by setting an operation switch, for example, and based on information from a front recognition device (camera, laser radar, etc.). To detect the inter-vehicle distance between the host vehicle and the preceding vehicle and control the engine output and brake so that the inter-vehicle distance becomes the target inter-vehicle distance so that the vehicle can follow the preceding vehicle. It is a thing.

  By the way, when it rains, the road surface of the road gets wet and slips easily and slips easily. For this reason, in the above-mentioned inter-vehicle distance control device, when rainy weather is detected based on information from a rainy weather detection device (raindrop sensor, wiper operation, etc.), the target vehicle distance is longer than that in fine weather and the set vehicle speed is smaller than that in fine weather. By controlling the engine output and the brake as described above, excessive approach to the preceding vehicle due to slip is prevented (for example, see Patent Documents 1 to 3 below).

Japanese Patent Publication No.6-23020 Japanese Patent Laid-Open No. 10-138792 JP-A-11-34693

  However, in the conventional inter-vehicle distance control device as described above, although it is possible to prevent the vehicle from approaching the preceding vehicle too much due to slip due to wetness on the road surface in rainy weather, the target inter-vehicle distance and It has been difficult to reliably prevent the slip itself when the acceleration / deceleration control is performed so that the set vehicle speed is smaller than that in clear weather, and further reduction of the driver's burden has been demanded.

  Such a problem is not limited to the inter-vehicle distance control device as described above, and is also the same as that described above, for example, in a constant speed travel control device that controls the vehicle speed of the host vehicle so that the host vehicle travels at a desired constant speed. Can occur.

  Accordingly, an object of the present invention is to provide a vehicle travel control device that can reliably prevent slipping even when acceleration / deceleration control is performed in rainy weather.

  In order to solve the above-described problem, the vehicle travel control apparatus according to the first aspect of the present invention is such that the distance between the vehicle and the preceding vehicle traveling in the same travel lane as the host vehicle is set to a predetermined value. In a vehicle travel control apparatus for controlling the vehicle speed of a vehicle or controlling the vehicle speed of the host vehicle so that the host vehicle travels at a predetermined speed, a rainfall detection unit that detects rainfall, and information from the rainfall detection unit Based on the rain condition correlation parameter ε, and when the rain condition correlation parameter ε is not less than the lower limit value α1 and not more than the upper limit value α2, the maximum allowable acceleration Amax is calculated based on the rain condition correlation parameter ε and the vehicle speed Vs. And control means for performing at least one of engine output control and brake control so as not to exceed the maximum allowable acceleration Amax.

  In the vehicle travel control apparatus according to a second aspect of the present invention, in the first aspect, the control means further calculates a vehicle speed limit Vw based on the rainfall state correlation parameter ε, and the maximum allowable acceleration Amax. The engine output control and the brake control are performed in accordance with the limited vehicle speed Vw so as not to exceed.

  According to a third aspect of the present invention, there is provided the vehicle travel control apparatus according to the first or second aspect, wherein the control means controls the engine output in the normal mode when the rainfall state correlation parameter ε is smaller than the lower limit value α1. And at least one of brake control.

  According to a fourth aspect of the present invention, in the vehicle travel control apparatus according to any one of the first to third aspects, the control means performs the control when the rainfall state correlation parameter ε is larger than the upper limit value α2. It is characterized by stopping.

  According to the vehicle travel control apparatus of the first aspect of the present invention, slip can be reliably prevented even during acceleration / deceleration control during rain, so travel control consistent with the driver's feeling can be performed. Further reduction of the burden on the driver can be achieved.

  According to the vehicle travel control apparatus of the second aspect of the present invention, safety during rain can be further improved.

  According to the vehicle travel control apparatus of the third aspect of the present invention, the control can be automatically switched between raining and clear weather.

  According to the vehicle travel control apparatus of the fourth aspect of the invention, it is possible to automatically switch to manual operation during heavy rain that is difficult to control.

  An embodiment in which a vehicle travel control device according to the present invention is applied to an inter-vehicle distance control device will be described with reference to FIGS. FIG. 1 is a schematic configuration diagram of the vehicle travel control device, FIG. 2 is a control flow diagram of the vehicle travel control device, and FIG. 3 shows the relationship between the vehicle speed Vs and the maximum allowable acceleration Amax for each rain condition correlation parameter ε. It is the map shown.

  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 travel control device (auto cruise controller) of the vehicle 1 is electrically connected to the input portion of the ECU 30, and the control state of the auto cruise controller is connected to the output portion of the ECU 30. The ECU 24 is electrically connected, and the ECU 30 controls the engine output and the brake by controlling the travel adjusting devices 21 to 23 based on the information from the information devices 11 to 17. 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 lower limit value α1 (step S2). If the parameter ε is smaller than the lower limit value α1, the ECU 30 performs normal mode control, that is, the laser radar. 11, based on information from 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 information from the inter-vehicle distance D and the wheel speed sensor 15 (vehicle speed) Vs), the throttle actuator 21, the A / T controller 22, and the brake actuator 23 are controlled to control the engine output and the brake so that the target inter-vehicle distance Dt is set in advance according to the vehicle speed Vs. (Step S3) (For more details, refer to JP-A-10-138792 [0018] to [0031] etc.)Thus, 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 to the predetermined value Dt.

  If the parameter ε is greater than or equal to the lower limit value α1, the ECU 30 subsequently compares the parameter ε with a preset upper limit value α2 (step S4), and the parameter ε is greater than the upper limit value α2. If it is too large, it is determined that the influence of rainfall is great, and the control is stopped (step S5).

  When the parameter ε is equal to or less than the upper limit value α2, the ECU 30 not only obtains the limit vehicle speed Vw set in advance according to the magnitude of the parameter ε from the map (step S6), but also the wheel speed. Based on the information from the sensor 15 (vehicle speed Vs), the relationship between the vehicle speed Vs and the maximum allowable acceleration Amax as shown in FIG. The maximum allowable acceleration Amax is further obtained (step S7).

  Subsequently, the ECU 30 controls the throttle actuator 21, the A / T controller 22, and the brake actuator 23 in accordance with the limit vehicle speed Vw so as not to exceed the maximum allowable acceleration Amax, thereby controlling engine output and brakes. I do. (Step S8).

  That is, in the present embodiment, not only the limit vehicle speed Vw corresponding to the rain is set, but also the maximum allowable acceleration Amax corresponding to the rain is further set.

  For this reason, in this embodiment, slip can be reliably prevented even when acceleration / deceleration control is performed in rainy weather.

  Therefore, according to the present embodiment, it is possible to perform traveling control that matches the feeling of the driver, and to further reduce the burden on the driver.

  In the present embodiment, the case where the control unit controls both the engine output control and the brake control has been described. However, the present invention is not limited to this, and the control unit is at least one of the engine output control and the brake control. Even if it is a case where it performs, the effect similar to the case of this embodiment can be expressed.

  Further, in the present embodiment, a case where the present invention is applied to an inter-vehicle distance control device that controls the vehicle speed of the host vehicle so that the inter-vehicle distance with a preceding vehicle traveling in the same lane as the host vehicle is set to a predetermined value will be described. However, the present invention is not limited to this. For example, the present invention also applies to a constant speed travel control device that controls the vehicle speed of the host vehicle so that the host vehicle travels at a predetermined speed. Can be applied.

  The vehicle travel control apparatus according to the present invention can be used very effectively in the automobile industry.

1 is a schematic configuration diagram of an embodiment of a vehicle travel control device according to the present invention. It is a control flowchart of embodiment of the traveling control apparatus of the vehicle which concerns on this invention. It is the map which showed the relationship between the vehicle speed Vs and the maximum permissible acceleration Amax for every rain condition correlation parameter (epsilon).

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)

Claims (4)

The vehicle speed of the host vehicle is controlled so that the inter-vehicle distance from the preceding vehicle traveling in the same travel lane as the host vehicle is a predetermined value, or the host vehicle is driven at a predetermined speed. In a vehicle travel control device that controls vehicle speed,
Rain detection means for detecting rainfall;
Based on the information from the rain detection means, the rain state correlation parameter ε is calculated. When the rain state correlation parameter ε is not less than the lower limit α1 and not more than the upper limit α2, the rain state correlation parameter ε and the vehicle speed Vs are set. And a control means for performing at least one of engine output control and brake control so as to calculate a maximum allowable acceleration Amax based on the maximum allowable acceleration Amax and not to exceed the maximum allowable acceleration Amax. Control device. In claim 1,
The control means further calculates a limit vehicle speed Vw based on the rainfall state correlation parameter ε, and performs engine output control and brake control corresponding to the limit vehicle speed Vw so as not to exceed the maximum allowable acceleration Amax. A vehicle travel control device that performs at least one of them. In claim 1 or claim 2,
When the rainfall state correlation parameter ε is smaller than the lower limit value α1, the control means performs at least one of engine output control and brake control in a normal mode. In any one of Claims 1-3,
When the rainfall state correlation parameter ε is larger than the upper limit value α2, the control means stops the control.

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