Seiko Epson Corporation

Shinichi Mitsunaga

Mikio Nagahara

An inertial sensor module includes: a first inertial sensor; a second inertial sensor; and a processing device configured to receive a first detection signal output from the first inertial sensor and a second detection signal output from the second inertial sensor, and output measurement data based on the first detection signal and the second detection signal and based on output instruction information received from outside. The processing device is configured to output the measurement data in a format corresponding to output format selection information received from the outside.

Inertial sensor module and inertial measurement system

An evaluation point E of a present position candidate corresponding to each satellite set is calculated based on an a priori residual (APR) (APR value), a PDOP value, and the number of satellites of the target satellite set according to E=k&#xb7;f(APR)+k&#xb7;f(PDOP)+k&#xb7;f(number of satellites). Evaluation coefficients kto kfor respectively weighting evaluation functions fto fare determined based on an APR average value.

Present position locating method

In the first positioning, a positioning process that calculates the present position based on acquired GPS satellite signals (step A) is performed a plurality of times. A number of times that the difference (position difference) &#x394;P between the calculated present located position and the preceding located position is successively equal to or less than a given value is counted using a position counter, and a number of times that the difference (time difference) &#x394;T between the present time error and the preceding time error is successively equal to or less than a given value is counted using a time counter each time the positioning process is performed (step A). A position threshold value and a time threshold value are determined by changing a reference threshold value by an amount corresponding to an APR average value (step A). When the position count value has reached the position threshold value (step A: YES) and the time count value has reached the time threshold value (step A: YES), the present position is determined to be the first located position and output (step A).

First output position calculation method, storage medium, positioning device, and electronic instrument

A reception environment is determined to be a multipath environment when the difference (positioning altitude difference) between the maximum value (maximum altitude) and the minimum value (minimum altitude) of the altitudes of candidate present positions P of respective satellite sets exceeds a given threshold value (e.g., 200 m), and is determined to be an open-sky environment when the positioning altitude difference is equal to or less than the given threshold value. When the reception environment is the open-sky environment, an evaluation point E of each satellite set is calculated using a known evaluation method based on the number of satellites, a PDOP value, and the like. When the reception environment is the multipath environment, the evaluation point E of each satellite set is calculated in the same manner as in the open-sky environment, and a change amount &#x394;E corresponding to the difference (altitude difference) between the altitude corresponding to the preceding located position acquired from an altitude table and the altitude of the candidate present position of the target satellite set is subtracted from the evaluation point E.

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Kanagawa, Japan

Shinichi Mitsunaga