US 6,618,690 B1 · Generalized positioning system based on use of a statistical filter

Abstract

A generalized positioning system, corresponding method, and filter for use in the generalized positioning system, based on Kalman filtering or any other kind of filtering that produces an estimate of position, or other aspect of the motion of an object, using statistical measures involving current and previous measurements of position or any other aspect of the motion of the object, but with greater responsiveness than a positioning system based on the usual statistical filtering, such as Kalman filtering. The generalized positioning system uses a calculated association probability for each measurement in a set of measurements of position (or other aspect of the motion) at a particular instant of time, the association probabilities being used in the calculation of a combined measurement innovation (residual), which is in turn used in calculating the next estimate of position (or other motion state information). In one aspect of the invention, a pre-validation is performed, based on a usually pre-determined gate width of a validation region. By using a combined measurement innovation, the generalized positioning system is able to accept simultaneous measurements from different sources of information, including different kinds of sources of information, so that it can provide position estimates (or estimates for other components of the state of motion, i.e. of other aspects of the motion) based on, e.g., information received both from satellites, used in a global positioning system, and also from cellular base station in a cellular telephone network.

Claims23

Dependent claims

An improved generalized positioning system, for making estimates of state information of an object, the state information being information about the state of motion of the object, having a filter that statistically determines a succession of state estimates along with corresponding uncertainty estimates based on a succession of state measurements, the improvement comprising:

a) means for determining association probabilities for a plurality of state measurements all at a same instant of time, each association probability corresponding to a particular state measurement at the instant of time, and also means for determining an association probability providing a value for the probability that none of the plurality of measurements is correct;
b) means for combining into a single measurement innovation each individual innovation using the association probabilities as weightings;
and
c) means for determining the covariance of the updated state based on the individual association probabilities, the association probability for providing a value for the probability that none of the measurements is correct, and the combined measurement innovation.

1 more element

A method, for use in making estimates of state information of an object, the state information being information about the state of motion of the object, the method for performing a filtering that statistically determines a succession of state estimates along with corresponding uncertainty estimates based on a succession of state measurements, the method comprising the steps of:

a) determining association probabilities for a plurality of state measurements all at a same instant of time, each association probability corresponding to a particular state measurement at the instant of time, and also determining an association probability providing a value for the probability that none of the plurality of measurements is correct;
b) combining into a single measurement innovation each individual innovation using the association probabilities as weightings;
and
c) determining the covariance of the updated state based on the individual association probabilities, the association probability for providing a value for the probability that none of the measurements is correct, and the combined measurement innovation.

1 more element

A filter, for making estimates of state information of an object, the state information being information about the state of motion of the object, the filter statistically determining a succession of state estimates along with corresponding uncertainty estimates based on a succession of state measurements, the filter comprising:

a) means for determining association probabilities for a plurality of state measurements all at a same instant of time, each association probability corresponding to a particular state measurement at the instant of time, and also means for determining an association probability providing a value for the probability that none of the plurality of measurements is correct;
b) means for combining into a single measurement innovation each individual innovation using the association probabilities as weightings;
and
c) means for determining the covariance of the updated state based on the individual association probabilities, the association probability for providing a value for the probability that none of the measurements is correct, and the combined measurement innovation.

1 more element

Dependencies are inferred from the claim text.

Generalized positioning system based on use of a statistical filter

Life of this patent

Generalized positioning system based on use of a statistical filter

Life of this patent

Abstract

Claims23