Data processing: vehicles – navigation – and relative location – Vehicle control – guidance – operation – or indication – Vehicle subsystem or accessory control
Reexamination Certificate
2002-08-30
2004-04-06
Black, Thomas G. (Department: 3663)
Data processing: vehicles, navigation, and relative location
Vehicle control, guidance, operation, or indication
Vehicle subsystem or accessory control
C701S001000, C348S148000, C348S119000, C180S443000, C180S168000
Reexamination Certificate
active
06718241
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a travel control apparatus that recognizes lane markings on the road from images recorded by a camera, and carries out travel control such that the vehicle travels along these lane markings.
2. Description of the Related Art
In the conventional vehicle steering apparatus disclosed, for example, in Japanese Unexamined Patent Application, First Publication, No. Hei 11-78948, is known in which lines on the road (for example, lane markings such as white lines) are detected by processing images obtained from a camera mounted on the vehicle that records the travel path, and compensates the steering torque input by the driver so that the vehicle travels along this line.
However, in the vehicle steering apparatus according to the conventional technology described above, in the case that the detection of the lines on the road is impossible, the execution of the steering control that compensates the steering torque input by the driver is suspended, and inappropriate steering control is prevented by restarting the steering control at a point in time when the detection of the line on the road can be detected.
However, the frequency that the detection of lines on the road becomes impossible due to the state of the surface of the road being traveled, or the state of the road surface, for example, accumulated snow, a bad surface, a wet surface, or the road surface in a tunnel or the like is high, and there are cases in which the steering control is switched on and off frequently. Thereby, the compensation of the steering torque input by the driver switches ON and OFF frequently, and there is a concern that this may cause discomfort for the driver.
In consideration of the above described problems, it is an object of the present invention to provide a travel control apparatus for a vehicle that carries out appropriate travel control so that the vehicle travels along recognized lane markings, and at the same time can prevent making the driver feel discomfort while travel control is being carried out.
SUMMARY OF THE INVENTION
In order to solve the problems described above and attain the object, in a first aspect of the vehicle travel control apparatus according to the present invention that comprises a travel path recognizing device (for example, the camera
25
and the image recognition processing unit
26
in the embodiments described below) that recognizes the travel path of the vehicle, a recognition condition determining device (for example, step S
01
, step S
04
, and step S
07
in the embodiments described below) that determines the quality of the recognition condition of the travel path recognizing device, and a travel control device (for example, step S
10
in the embodiments described below) that determines the possibility of executing the travel control for the vehicle using the results of the recognition of said travel path recognizing device based on the results of the determination of the recognition condition determining device, wherein said travel control device determines the possibility of executing the travel control for the vehicle based on at least one of the favorably determined continuous condition or the unfavorably determined continuous condition that is determined by the recognition condition determining device.
According to a vehicle travel control apparatus having the structure described above, the travel path recognition device analyses image data or the like of the travel path obtained by video recording using, for example, cameras mounted on the vehicle, and recognizes the lane markings, such as the white lines, on the travel path. At this time, the recognition condition determining device determines the quality of, for example, the recognition condition of the sequence of recognition processing and recognition results in the travel path recognizing device, for example, the possibility of recognition or the precision of the recognition results. In addition, the possibility of executing the travel control depends not simply on the results of the determination of the quality of the recognition condition determining device, but also on each continuing condition of the quality determination, such as the history of each continuous time interval.
Thereby, for example, even in the case that the quality determination in the recognition condition determining device switches frequently, it is possible to prevent the accompanying possibility of execution of the travel control from switching frequently, and the recognition condition determining device appropriately sets the possibility of execution of the travel control such that it is appropriately switched depending on each continuation condition of a favorable determination or unfavorable determination, and thereby it is possible to prevent the driver from feeling discomfort.
In a second aspect of the vehicle travel control apparatus according to the present invention, said continuous condition of the quality determination by the recognition condition determining device is the continuous time interval from the starting time of the favorable determination or unfavorable determination (for example, the count value of the ON time measuring counter TON and the count value of the OFF time measuring counter TOFF in the employments described below), and said travel control device determines the possibility of execution of the travel control of the vehicle based on a reference time (for example, the delay time TD in the embodiments described below) that is increased or decreased depending on the continuous time interval.
According to the vehicle travel control apparatus having the structure described above, for example, the longer the continuous time interval of the favorable determination, the travel control device determines that there exists a state appropriate for executing the travel control using the result of the recognition of the travel path recognizing device, and the reference time, for example the delay time when the possibility of execution of the travel control is switched, is decreased. In contrast, for example, the longer the continuous time interval of the unfavorable determination, the travel control device determines that there exists a state that is not appropriate for executing the travel control using the result of the recognition of the travel path recognizing device, and a reference time, for example, the delay time when the possibility of execution of the travel control is switched, is increased.
Thereby, the travel control device can determine the possibility of executing travel control by suitably determining whether or not it is in a state appropriate for executing the travel control using the result of the recognition of the travel path recognizing device based on the reference time, and thereby it is possible to prevent making the driver feel discomfort while travel control is being executed.
Furthermore, a third aspect of the vehicle travel control apparatus according to the present invention comprises a reference time update device (for example, step S
02
and step S
05
in the embodiments described below) that decreases said reference time in the case that there is a favorable determination by the recognition condition determining device and increases said reference time in the case that there is an unfavorable determination by the recognition condition determining device, and said travel control device compares the reference time with the favorable determination continuous time interval (for example, the count value of the ON time measuring counter TON in the embodiments described below) that is the continuous time interval from the start time of the favorable determination by said recognition condition determination device, and when the favorable determination continuous time interval is longer than said reference value, the execution of the travel control of the vehicle is permitted.
According to the vehicle travel control apparatus having the structure described above, during the switching of the possib
Ishida Shinnosuke
Kondo Satoshi
Tanaka Jun
Arent & Fox PLLC
Black Thomas G.
Honda Giken Kogyo Kabushiki Kaisha
Mancho Ronnie
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