Honda Giken Kogyo Kabushiki Kaisha

Yuji Sakaki

Shohei Matsuda

Makoto Otabe

Keiyu Kin

Hiroshi Sekine

Yoshimitsu Akuta

A road shape predicting method includes the steps of: selecting three positions of positions of a plurality of nodes constituting road map data and an own vehicle position on a road; and predicting the road shape on the basis of a crossing angle formed by a link connecting a first position and a second position of the selected three positions and another link connecting the second and a third position thereof, and a link length between the second and the third positions. In case that the link length between the second and the third positions is not larger than a reference link length set in accordance with the crossing angle, the third position is excluded, and the position of a node further forward is adopted in place of the third position, to thereby predict the road shape.

Road shape predicting method and vehicle controlling method

A system for determining the passability of a vehicle through a section of road ahead of the vehicle is controlled based on coordinates of a plurality of nodes N,(N,, N,, N,, N,. . . ) constituting the road section ahead of a subject vehicle. The system calculates a passing-state determination amount &thgr;,/L,for each of the nodes N,, and based on the passing-state determination amount &thgr;,/L,, the system then determines whether the vehicle can positively or safely pass through the road section. The passing-state determination amount &thgr;,/L,serves as an indicator which represents a degree of difficulty in the passage of the vehicle through the nodes N,and which is obtained, for example, by dividing an angle &thgr;,formed by a line segment connecting the adjacent nodes N,by a distance L,between the adjacent nodes N,. Even if only one or two nodes N,exist on a curve, it is possible to accurately determine whether the vehicle can pass the curve by using the passing-state determination amount &thgr;,/L,.

System for determining passability of vehicle

A system for determining the passability of a vehicle passing through a curved road section. The system provides road information, detects the position of a subject vehicle on the road and determines whether a node, representing road data, exists on a curved or straight section of road. If it is determined that the node exists on a curve, it is then determined whether the curve is a simple curve or an S-shaped curve. Based upon these determinations, the system determines whether the vehicle can safely pass through the curve.

Vehicle control apparatus enables a vehicle to positively and safely pass a curve present in a forward road ahead of the vehicle, irrespective of any error in road data used by the apparatus and any error in a detected vehicle position. The apparatus calculates a predicted passing speed for a curve on the basis of a vehicle speed and a vehicle position, and compares same with a maximum passable speed for the curve which is calculated on the basis of map information and the vehicle position to thereby determine whether the vehicle can positively and safely pass the curve. If the apparatus determines that the vehicle cannot positively and safely pass the curve, warning, automatic deceleration and/or automatic steering is executed by a control mechanism of the apparatus. At this time, the apparatus compares an actual transverse acceleration or an actual yaw rate detected by a transverse acceleration sensor or a yaw rate sensor with a reference transverse acceleration or a reference yaw rate presumed from a road shape determined by a passage-state decision quantity calculating mechanism, and a regulating mechanism regulates a controlled variable and a control timing for effecting the warning, the automatic deceleration and/or the automatic steering, thereby compensating for any error in the road data and any error in the vehicle position.

Vehicle control apparatus

A vehicle control apparatus is operative so as to prevent a chattering of initiation and termination of vehicle control, such as automatic deceleration, on the basis of a variation in a predicted passing speed. The apparatus comprises a maximum passable speed calculating mechanism M5 which calculates a maximum passable speed of a forward curve ahead of the vehicle on the basis of a road shape determined by a road shape decision mechanism M11, and a predicted passing speed calculating mechanism M7 calculates a predicted passing speed for the forward curve on the basis of a vehicle speed detected by a vehicle speed detector M6. The maximum passable speed includes a control initiation speed and a control termination speed larger than the control initiation speed, and a passage-possible/impossible determining mechanism M8 initiates operations of a warning mechanism M9 and a vehicle speed regulating mechanism M10 if the predicted passing speed exceeds the control initiation speed, and terminates the operations of the warning mechanism M9 and the vehicle speed regulating mechanism M10 if the predicted passing speed falls below the control termination speed.

A hydroplaning detection system comprising AM specific frequency component extraction AM, which comprises a band-pass filter for extracting signal components PS in a main frequency band corresponding to the wheel rotation speed or the vehicle speed from wheel rotation speed signals, and a band-pass filters for respectively extracting signal components PL in other frequency bands, and AM determining the occurrence of hydroplaning based on the ratio PL/PS between the signal components PS in the main frequency band and the signal components PL in other frequency bands.

Hydroplaning detector apparatus

An apparatus for detecting a wheel grip on a road has a wheel speed sensor for detecting a revolution speed of a wheel of a vehicle, a plurality of band-pass filters for filtering an output of the wheel speed sensor at a plurality of frequency bands, and a reference value memory device for storing in memory reference values dependent on the revolution speed of the wheel. The reference values are set for each of the frequency bands of the plurality of band-pass filters. The wheel grip on road is detected based on the correlation between that signal output for each of the frequency bands which is obtained through the band-pass filters and that reference value for each of the frequency bands which is stored in memory in the reference value memory device.

Growing community of inventors

Saitama, Japan

Yuji Sakaki