Patent ID: 8838409

Claim:
An installation error estimating apparatus that estimates an installation error of a tag reader that positions a wireless tag, the installation error estimating apparatus comprising: a central processing unit that executes instructions stored in a memory; wherein the central processing unit comprises; a predicted pattern acquirer that acquires, for each observation point where the wireless tag is installed and positioned, a predicted positioning distribution pattern, which is obtained by calculating a characteristic pattern of a predicted positioning distribution obtained by predicting a positioning distribution, the positioning distribution representing a distribution of a plurality of positioning results of the observation point; an observation data inputter to which the plurality of positioning results of the tag reader with respect to the wireless tag is input as observation data; a variance pattern analyzer that calculates, as a measured positioning distribution pattern, a characteristic pattern of a measured positioning distribution, which is obtained by statistical analysis of the plurality of positioning results, for each observation point, based on the observation data input by the observation data inputter; and an installation error estimator that calculates an installation error of the tag reader, the installation error representing at least one of an orientation deviation of the tag reader and a position deviation of the tag reader, using the predicted positioning distribution pattern acquired by the predicted pattern acquirer and the measured positioning distribution pattern calculated by the variance pattern analyzer, wherein the predicted pattern acquirer comprises: an observation point information setter that sets information relating to the observation point as observation point information; and a predicted pattern calculator that calculates, as the predicted positioning distribution pattern, the characteristic pattern of the predicted positioning distribution obtained by predicting the positioning distribution, for each observation point, based on the observation point information set by the observation point information setter, wherein the predicted pattern calculator calculates, for each observation point, the predicted positioning distribution pattern using a distribution obtained by projecting the predicted positioning distribution in a predetermined tangential direction at the observation point on a spherical surface having a line segment linking an installation position of the tag reader to the observation point as a radius; and the variance pattern analyzer calculates the measured positioning distribution pattern using a distribution obtained by projecting the measured positioning distribution in the tangential direction for each observation point.