Pioneer Corporation

Kazuaki Tanaka

Seiji Goto

Tatsuya Okamoto

Isao Endo

A signal acquisition sectionacquires, for example, a vehicle velocity pulse signal, which is generated from a vehicle velocity sensorin accordance with the movement of a vehicle that is a mobile body. A distance information acquisition sectionacquires distance information concerning the movement distance of the vehicle from a GPS receiver. A distance factor computing sectioncomputes a distance factor value based on the acquired vehicle velocity pulse signal and distance information. A change detection sectionthen compares this computed distance factor value and a distance factor reference value stored in a reference value storage sectionto detect a continuous change of the distance factor value. That is, change detection sectiondetects a change of tire outer diameter due to a change of the pneumatic pressure of the vehicle's tire or tire exchange, etc. When the change of tire outer diameter is detected by change detection section, a distance factor correction sectioncorrects the distance factor reference value speedily and appropriately.

DISTANCE FACTOR LEARNING DEVICE, DISTANCE FACTOR LEARNING METHOD, DISTANCE FACTOR LEARNING PROGRAM, RECORDING MEDIUM RECORDING SAID PROGRAM, MOVEMENT CONDITION COMPUTING DEVICE, AND PRESENT POSITION COMPUTING DEVICE

An on-vehicle navigation system is provided with a radio wave positioning apparatus ( ) and a vehicle speed sensor ( ) for a dead reckoning positioning. A method of detecting a vehicle speed pulse drop of a vehicle speed pulse generated by the vehicle speed sensor is provided with: a first calculation process of calculating a first physical quantity of a predetermined type such as a velocity or the like from radio wave positioning data of the radio wave positioning apparatus; a second calculation process of calculating a second physical quantity of the same type as the first physical quantity from the vehicle speed pulse; and a detection process of detecting the vehicle speed pulse drop by using a contradiction caused between the calculated first physical quantity and the calculated second physical quantity as a detection condition.

Method of and apparatus for detecting vehicle speed pulse drop, on-vehicle navigation system, program storage device and computer data signal embodied in carrier wave

A velocity information acquisition section acquires velocity information on the velocity of a vehicle and records this acquired information in a velocity information recording section . A state judgment section judges start and stop states of the vehicle based on state information indicating the start and stop states of the vehicle that was acquired at a state information acquisition section . After this judgment, a minimum output velocity computing section accurately computes, based on the velocity information recorded in velocity information recording section , a minimum output velocity in a period in which a vehicle velocity detection circuit cannot detect velocity information. A movement condition computing section can appropriately compute a relative movement distance or a relative movement velocity of the vehicle based on the state information acquired at state information acquisition section and the minimum output velocity computed at minimum output velocity computing section

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Kawagoe, Japan

Kazuaki Tanaka