Seiko Epson Corporation

Shigeru Imafuku

Shunichi Mizuochi

Mikio Nagahara

Akifumi Hayashi

Tomoyuki Kurata

Kumar Anand

Kenji Onda

Eiji Kinoshita

Hidekazu Maezawa

A location of a mobile unit is intermittently measured based on a GPS satellite signal. A halt start time zone (first halt determination region) is set based on the measured location of the mobile unit when the determination is started. An each time zone (second halt determination region) is updated and set by accumulated averaging processing (statistical processing) of results of location measurements in the past. Whether or not the halt state of the mobile unit is continued is determined using whether or not the newly measured location of the mobile unit is contained in any one of the set halt determination regions.

Halt continuation determination method and halt continuation determination device

A position calculating method performed by a position calculating device having a sensor unit carried by or mounted on a mobile body and moving with the mobile body, includes: calculating the position of the mobile body; setting a detection value agreement range of the sensor unit for each of the possibility of moving, possibility of uncertainty, and possibility of stopping of the mobile body, and setting the detection value agreement range of the possibility of moving as the widest range to establish a membership function; determining whether the mobile body is in the stopping condition by predetermined fuzzy inference calculation using the membership function; changing an error parameter used for predetermined Kalman filter process to correct the calculated position by the Kalman filter process according to whether the stopping condition of the mobile body is determined or not; and correcting the calculated position by the Kalman filter process.

Position calculating method and position calculating device

A position calculating method includes: calculating a position of a mobile body based on a positioning signal from a positioning satellite; determining the moving condition of the mobile body based on a detection result of a sensor unit including at least one of an acceleration sensor, an angular speed sensor, and an azimuth sensor; changing an error parameter used for a predetermined Kalman filter process according to the determined moving condition; and correcting the calculated position by the Kalman filter process.

A terminal device includes a plurality of search channel sections which search for a positioning satellite, a candidate reception frequency calculation section which calculates a candidate reception frequency of a first acquisition target satellite by causing the search channel sections to perform the correlation accumulation process for a first accumulation time, a candidate frequency confirmation section which confirms reliability of the candidate reception frequency by causing the search channel sections to perform the correlation accumulation process for a second accumulation time longer than the first accumulation time, a final frequency calculation section which calculates a final frequency by causing the search channel sections to perform the correlation accumulation process for a third accumulation time longer than the second accumulation time, and a first difference calculation section which calculates a difference between an estimated synchronization frequency corresponding to each first acquisition target satellite and the final frequency.

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Nagano, Japan

Shigeru Imafuku