JP2765310B2 - Automotive radar equipment - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an on-vehicle radar device, and more particularly to an on-vehicle radar device having an improved radar detection range when traveling on a curved road while capturing a preceding vehicle.

[0002]

2. Description of the Related Art Conventionally, there has been known a preceding vehicle detecting device for detecting a distance between vehicles and a relative speed to a preceding vehicle for the purpose of securing a safe inter-vehicle distance or performing automatic following. As such a preceding vehicle detection device, a radar device, a laser radar device, and the like are conventionally used, but when the preceding vehicle and the own vehicle do not exist on the same straight line, for example, on a curved road. If the direction of the radar beam emitted from the radar device is fixed, the preceding vehicle cannot be detected. Therefore, conventionally, a scanning type laser radar device which scans a radar beam within a predetermined range or a steer type radar device which detects a curved road by some means and turns the beam according to the curved road has been proposed. I have.

For example, in a vehicle radar sensor disclosed in Japanese Patent Laid-Open Publication No. Sho 51-30490, a radiator of the radar sensor is linked with a steering wheel of a vehicle, and radiated from the radiator in accordance with a steering angle of the steering wheel. This is to change the direction of the radar beam.

Accordingly, even when the preceding vehicle and the own vehicle are both traveling on a curved road, the steering angle of the preceding vehicle and the own vehicle is almost the same, so that the radar beam is deflected according to the steering angle of the own vehicle. This makes it possible to catch the preceding vehicle.

[0005]

However, in such a configuration in which the radar device is simply deflected in accordance with the steering angle of the steering wheel, a vehicle that cuts in from an adjacent lane may be provided depending on the positional relationship between the preceding vehicle and the own vehicle. There was a problem that the vehicle could not be captured, and thus the distance between the vehicle and the interrupted vehicle could not be secured quickly.

For example, as shown in FIG. 6, both the own vehicle and the preceding vehicle are traveling on a curved road, and the radar beam is deflected according to the steering angle of the own vehicle in order to catch the preceding vehicle. Assume a situation where When there is a large inter-vehicle distance between the host vehicle and the preceding vehicle, another vehicle may be able to cut in from the adjacent lane. However, this interrupted vehicle is out of the radar beam detection range (in FIG. 6, it is detected by diagonal lines). (Interval is shown), it is not possible to catch the vehicle.Because it is only captured when the interrupted vehicle enters the radar beam detection range, if the inter-vehicle distance to this interrupted vehicle is short, There was a problem that drivability deteriorated because sudden braking of the car was required.

SUMMARY OF THE INVENTION The present invention has been made in view of the above-mentioned problems of the prior art, and has as its object the purpose of another approach between a host vehicle and a preceding vehicle when the vehicle approaches a curve while catching the preceding vehicle with a radar device. It is an object of the present invention to provide an on-vehicle radar device capable of quickly and reliably capturing an interrupted vehicle even if the vehicle is interrupted.

[0008]

In order to achieve the above object, a vehicle-mounted radar device according to the present invention, as shown in FIG. 1, determines a distance between a radar 1 for detecting a preceding vehicle and a preceding vehicle. An inter-vehicle distance detecting means 2 for detecting, a relative speed detecting means 3 for detecting a relative speed with respect to a preceding vehicle, a steering angle detecting means 4 for detecting a steering angle of the own vehicle, and the own vehicle traveling on a curved road A curved lane detecting means 5 for detecting that the vehicle is traveling on a curved lane, the inter-vehicle distance is equal to or greater than a predetermined value, and the relative speed is within a predetermined range including 0, and A driving unit 6 that rotates by a predetermined amount in a direction opposite to the steering of the vehicle, and whether the detected vehicle is located in its own lane when a vehicle other than the preceding vehicle is detected by the rotation of the radar 1 by the driving unit 6. Determining means 7 for determining whether or not And butterflies.

[0009]

The on-vehicle radar device according to the present invention has the above-described configuration. When the traveling state of the own vehicle and the preceding vehicle is in a predetermined state while traveling on a curved road, another vehicle is started from the adjacent lane. It is determined that there is a high possibility that the vehicle will be interrupted.In this case, the radar is rotated in the direction opposite to the steering angle of the own vehicle, that is, the direction in which the interrupted vehicle is interrupted, and the detection range is changed to quickly move the interrupted vehicle. Is to be captured.

Here, the predetermined state in which there is a high possibility that another vehicle will be interrupted means that the distance between the own vehicle and the preceding vehicle is large, and that the own vehicle and the preceding vehicle run at substantially the same speed. Therefore, if the inter-vehicle distance is equal to or more than a predetermined value and the relative speed is within a predetermined range, the radar is rotated in the reverse direction by the driving means to change the detection range, and the interrupted vehicle is quickly captured. I do.

[0011]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS A preferred embodiment of a vehicle-mounted radar device according to the present invention will be described below with reference to the drawings, taking as an example a case where the vehicle is driven to follow.

FIG. 2 is a block diagram showing the configuration of this embodiment. A transmitter / receiver 10 for transmitting / receiving a triangular modulated wave as a radar is provided at a predetermined position in the front part of the vehicle, and detects a forward obstacle such as a preceding vehicle. And this transceiver 10
, That is, a composite signal of the transmission triangular modulation wave and the reception triangular modulation wave is input to the microcomputer 16 via the input port. The microcomputer 16 includes a ROM in which a predetermined calculation program is stored, a RAM in which calculation results are stored, and a CPU for performing calculation processing, and calculates a sum and a difference between a transmission triangular modulation wave and a reception triangular modulation wave. Detects the following distance and the relative speed to the preceding vehicle. Then, the detected inter-vehicle distance and relative speed are sequentially changed to RA.
M.

On the other hand, the vehicle speed sensor 12 and the steering angle sensor 1
4 are provided at predetermined positions of the vehicle, and detect the speed and the steering angle of the own vehicle and output them to the microcomputer 16. The microcomputer 16 processes these detection signals and supplies a control signal to the driving device 18 to control the rotation of the transceiver 10. When the inter-vehicle distance from the preceding vehicle is less than a predetermined allowable value, an alarm device is issued. In this configuration, an alarm signal is supplied to the driver 20 to notify the driver.

Hereinafter, the operation of the microcomputer 16 will be described in detail with reference to the flowchart of FIG. As described above, the steering angle data from the steering angle sensor 14 is input to the microcomputer 16, and it is determined using the steering angle data whether or not the own vehicle is traveling on a curved road (S101). ). This determination can be made based on, for example, whether or not a steering angle equal to or greater than a predetermined value is continuously input for a predetermined time.

If it is determined that the vehicle is traveling on a curved road, it is determined whether the vehicle is following the preceding vehicle (S102). This determination is performed in two stages. First, it is determined whether or not a tracking system switch (not shown) is turned on. Then, it is determined whether or not a preceding vehicle exists within the effective range of the radar.
Is determined based on whether finite data is supplied from.

When the following system switch is ON and the preceding vehicle is present, it is determined that the vehicle is following the preceding vehicle, and the inter-vehicle distance data and relative speed data for the past several seconds are monitored (S103). Specifically, the relative speed stored in the RAM is read out, and the magnitude of the relative speed RV is compared with a predetermined threshold value RV0 (S1).
04). If the magnitude RV of the relative speed is smaller than RV0, and therefore the own vehicle and the preceding vehicle are traveling at substantially the same speed, the inter-vehicle distance R and a predetermined threshold value R
The magnitude comparison with SO is performed (S105). When R ≧ RSO, the preceding vehicle and the own vehicle are separated and running at substantially the same speed as the preceding vehicle. This means that there is a high possibility that the user will be interrupted. If it is determined that such a state continues for a predetermined time Ti (0.1 to 0.3 sec: may be changed according to the vehicle speed) (S106), the interrupted vehicle is quickly captured. The radar is turned in the direction opposite to the steering, that is, in the direction in which it is interrupted.

However, as a result of detecting the interrupted vehicle by rotating the radar in this way, if there is no interrupted vehicle, the preceding vehicle that had been captured before the rotation must be captured again. It is necessary to maintain the following distance, relative speed, and steer angle with the preceding vehicle before moving. Therefore, the inter-vehicle distance and the relative speed to the preceding vehicle when the predetermined time Ti has elapsed are stored in another address of the RAM (S1).
07). Then, the transceiver 10 is rotated in the direction opposite to the steering angle to swing the radar beam, and the distance, relative speed, and steering angle to the obstacle at that time are detected (S1).
08). In this embodiment, the rotation angle is set to max 30 degrees with respect to the vehicle center line.

FIG. 4 shows how the radar beam swings in this manner. Both the own vehicle and the preceding vehicle travel on a curved road having a radius of curvature ρ, and the radar beam sequentially swings RL0, RL1, RL2, RL3 in the direction opposite to the steering. And if another vehicle is detected,
At this time, the detection distance R and the steering angle θ are detected, and a magnitude comparison is made between a threshold value group f (θ) which is predetermined according to the steering angle θ and stored in the ROM, and the detection vehicle moves on the own lane. Is determined (S109).

This threshold value group f (θ) is a value indicating the boundary between the adjacent lane in the direction opposite to the steering direction in FIG. 4, and using the elementary geometry theorem, f (θ) = − ρsin θ + ｛ ρ ² sin ² θ + ρw｝ ^0.5 . Here, ρ is the curvature of the curve, and w is the lane width.

FIG. 5 shows a threshold value group f (θ) when the curve curvature ρ is 300 m and the lane width w is 3.5 m. Note that the horizontal axis is the steer angle and the vertical axis is the detection distance. When the detection distance is equal to or smaller than the threshold value group f (θ), the detection vehicle is determined to be in the own lane, that is, determined to be an interrupting vehicle, and the interrupting vehicle is recognized as a new preceding vehicle, and the following process is performed. Is performed (S110).

On the other hand, if the detection distance R is larger than the threshold value group f (θ), that is, if the vehicle cannot be detected, or if it is determined that the vehicle is traveling on the adjacent lane even after the detection, Since it is necessary to re-capture the preceding vehicle in the own lane which has been captured before rotating the transceiver 10, the position of the preceding vehicle is predicted using the following distance, relative speed, and steering angle stored in the RAM in S107. Then, the radar beam is steered to that position (S120).

More specifically, the change in the inter-vehicle distance is calculated from the relative speed, and the steering angle before turning may be corrected by the change in the inter-vehicle distance.

As described above, in this embodiment, when the running state of the own vehicle and the preceding vehicle is in a state where the probability of the presence of the interrupted vehicle is high, the detection range of the radar is changed to detect the presence or absence of the interrupted vehicle. Therefore, the interrupted vehicle can be detected reliably and quickly, and the following can be smoothly performed.

[0024]

As described above, the on-vehicle radar device according to the present invention has an effect that it is possible to quickly and surely catch a vehicle that interrupts from an adjacent lane on a curved lane.

[Brief description of the drawings]

FIG. 1 is a configuration block diagram of the present invention.

FIG. 2 is a configuration block diagram of one embodiment of the present invention.

FIG. 3 is an operation flowchart of the microcomputer of the embodiment.

FIG. 4 is an explanatory view of the swing of the radar beam of the embodiment.

FIG. 5 is a graph showing a threshold value group f (θ) of the embodiment.

FIG. 6 is an explanatory diagram of a detection area on a curved track of the conventional device.

[Explanation of symbols]

 DESCRIPTION OF SYMBOLS 10 Transceiver 12 Vehicle speed sensor 14 Steering angle sensor 16 Microcomputer 18 Drive

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int.Cl. ⁶ , DB name) G01S 13/93 G01S 7/02 G01S 13/60 G08G 1/16 G01S 17/93

Claims (1)

(57) [Claims] 1. A radar for detecting a preceding vehicle, an inter-vehicle distance detecting means for detecting an inter-vehicle distance to the preceding vehicle, a relative speed detecting means for detecting a relative speed to the preceding vehicle, and detecting a steering angle of the own vehicle. A steering angle detection unit that detects that the vehicle is traveling on a curved road based on the steering angle; a vehicle traveling on a curved road, and the inter-vehicle distance is equal to or greater than a predetermined value. A driving means for rotating the radar by a predetermined amount in a direction opposite to the steering of the own vehicle when the relative speed is within a predetermined range including 0, and the preceding vehicle is rotated by the rotation of the radar by the driving means. Determining means for determining whether or not the detected vehicle is located in the own lane when a vehicle other than the detected vehicle is detected, and an on-vehicle radar device comprising: