Patent ID: 8560234
Filing Date: 2013-10-15
Classification: G01C,G01S

Abstract:
1. A method of estimating a plurality of vehicle dynamic states, the method comprising: receiving, by a processor, vehicle acceleration and angular rate data from an inertial measurement sensor disposed proximal to the vehicle; receiving, by the processor, vehicle position and velocity data from a satellite navigation system receiver disposed proximal to the vehicle, estimating, by the processor, vehicle dynamic states by mechanizing inertial navigation system equations with input including the vehicle acceleration and angular rate data from the inertial measurement sensor at a system update rate, said estimating being accomplished in a first time interval At said corresponding to a reciprocal of the system update rate; and updating, by the processor, the vehicle dynamic states with results of extended kalman filter matrix equations based on the received data from the inertial measurement sensor and on the received data from the satellite navigation system receiver, said updating including calculating at least a state transition matrix in a plurality of substeps na and subsequently a covariance matrix in a plurality of substeps np, determining, by the processor, whether a new position measurement has been received by the satellite navigation system receiver, and if the new position measurement has been received, updating the position states in a plurality of substeps npos if no new position measurement has been received, executing at least one blank step to maintain synchronization, determining, by the processor, whether a new velocity measurement has been received by the satellite navigation system receiver, and if the new velocity measurement has been received, updating the velocity motion states in a plurality of substeps nvel, or if no new velocity measurement has been received, executing at least one blank step to maintain synchronization, each of the substeps np being executed in an integration time interval Δtp equal to (nA +np +nvel +npos)×Δt such that said updating said vehicle dynamic states is accomplished in a second time interval greater than the first time interval Δt.