Title:
CAR SPEED DETECTING DEVICE
Document Type and Number:
Japanese Patent JPH01145239
Kind Code:
A
Abstract:
PURPOSE:To prevent the unnecessary control due to the erroneous car speed by outputting the car speed through the car speed calculation in the preceding time as the car speed at present when a pulse defect is generated in the car speed pulse cycle at present which is outputted from a switching means operated in accordance with the transfer of a vehicle. CONSTITUTION:A constant speed traveling device controls the opening degree of a throttle valve SV by duty-ratio-controlling a control valve V1 and a vent valve V2 in the direction for reducing the difference between the car speed memorized as a set car speed which is detected by a car speed sensor (lead switch SW2) during the turning-ON operation of a set switch SW2 and the traveling car speed at present. In this case, the ratio between the present value and the preceding value of the pulse cycle of the frequency corresponding to the car speed due to the lead switch SW2 is calculated, and it is judged if the ratio is over a prescribed value or not. When the ratio is less than the prescribed value, car speed calculation is carried out, while in case of the pulse defect with the value over the prescribed value, the car speed calculation is avoided, and a variety of controls are executed with the preceding car speed.
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Inventors:
OGAWA KENICHI
Application Number:
JP30207487A
Publication Date:
June 07, 1989
Filing Date:
November 30, 1987
Export Citation:
Assignee:
AISIN SEIKI
International Classes:
B60K31/06; B60T8/00; B60W30/00; F02D29/02; F16H59/44; F16H61/12; G01P3/481; (IPC1-7): B60K31/06; B60T8/00; F02D29/02; F16H5/48; G01P3/481
Attorney, Agent or Firm:
Higuchi Takehisa