Abstract: An equation derivation section derives an observation equation that employs M epochs worth of GPS data and INS data as observation values to derive for each of the GPS satellites a float solution for number of waves of GPS data carrier wave between each of plural GPS satellites and a vehicle, wherein the range of float solutions of the number of waves is constrained by the vehicle travel path estimated based on M epochs worth of INS data. The observation equation is solved by a float solution computation section and float solutions computed for the number of waves N and the position of the vehicle for each of the GPS satellites. Fixed solutions with highest consistency are computed by a fixed solution computation section based on the float solutions for the number of waves N for each of the GPS satellites and the position of the vehicle.

Abstract: A vehicle direction estimation section estimates an absolute direction of a heading direction of a vehicle based on GPS information and vehicle information. A satellite direction estimation section estimates an absolute direction of a target satellite of several satellites for positioning based on corresponding GPS information, and estimates a relative direction of the target satellite with respect to the heading direction based on the estimated absolute direction of the heading direction and the estimated absolute direction of the target satellite. A shield determination section determines a shielded state of the target satellite by determining whether a signal strength of a satellite signal from the target satellite is greater than a threshold value relative to a target partition of several partitions into which a three-dimensional sphere with respect to the heading direction is divided, the target partition which the calculated relative direction of the target satellite belongs to.

Abstract: The present invention provides a traffic simulator which can simulate traffic conditions with high accuracy. Cautionary object searching portion searches for cautionary objects which a driver should heed when driving a vehicle model; recognized cautionary object selection portion and driver-recognized cautionary object selection portion, based on driver ability information set by data creation portion, select cautionary objects recognized by a driver from the found cautionary objects; and movement determination portion determines the movement of a vehicle model based on the selected cautionary objects.

Abstract: A positioning apparatus includes: a first positioning device for calculating a reception position of a GPS receiver with respect to each combination of satellites based on a pseudo distance from each positioning satellite to the reception position; a component error calculator for calculating an error of at least one component in a calculation result of the first positioning device; a pseudo distance error calculator for obtaining a relation equation between the error of the at least one component and an error of the pseudo distance, and for solving simultaneous equations comprising the relation equation so that the error of the pseudo distance with respect to each positioning satellite is calculated; and a second positioning device for correcting the reception position based on the error of the pseudo distance.

Abstract: A vehicle direction estimation section estimates an absolute direction of a heading direction of a vehicle based on GPS information and vehicle information. A satellite direction estimation section estimates an absolute direction of a target satellite of several satellites for positioning based on corresponding GPS information, and estimates a relative direction of the target satellite with respect to the heading direction based on the estimated absolute direction of the heading direction and the estimated absolute direction of the target satellite. A shield determination section determines a shielded state of the target satellite by determining whether a signal strength of a satellite signal from the target satellite is greater than a threshold value relative to a target partition of several partitions into which a three-dimensional sphere with respect to the heading direction is divided, the target partition which the calculated relative direction of the target satellite belongs to.

Abstract: A positioning apparatus includes: a first positioning device for calculating a reception position of a GPS receiver with respect to each combination of satellites based on a pseudo distance from each positioning satellite to the reception position; a component error calculator for calculating an error of at least one component in a calculation result of the first positioning device; a pseudo distance error calculator for obtaining a relation equation between the error of the at least one component and an error of the pseudo distance, and for solving simultaneous equations comprising the relation equation so that the error of the pseudo distance with respect to each positioning satellite is calculated; and a second positioning device for correcting the reception position based on the error of the pseudo distance.

Abstract: A GPS receiver outputs pseudo distances each containing a clock bias error. A clock bias and a reception position are calculated based on each of the outputted pseudo distances. A clock drift is calculated based on clock biases at past n points or Doppler information outputted from the GPS receiver. Based on the calculated clock drift, a reference clock bias is estimated using a regression equation or a Kalman filter. Thereby, a position-fix accuracy is evaluated appropriately, without needing external data, such as autonomous navigation information.

Abstract: The present invention provides a traffic simulator which can simulate traffic conditions with high accuracy. Cautionary object searching portion searches for cautionary objects which a driver should heed when driving a vehicle model; recognized cautionary object selection portion and driver-recognized cautionary object selection portion, based on driver ability information set by data creation portion, select cautionary objects recognized by a driver from the found cautionary objects; and movement determination portion determines the movement of a vehicle model based on the selected cautionary objects.