US 6,664,918 B2 · Method and apparatus for identifying complex objects based on range readings from multiple sensors

Abstract

The invention is a method and apparatus for determining the shape and location of objects by trilateration based on the output of a plurality of range sensors. The range measurements from a plurality of sensors are correlated with each other to identify one or more potential objects. With respect to each potential object, it is assumed that the object can be one of a finite number of possible predefined shapes. For each potential object, a metric is calculated for each of the predefined shapes using the set of range measurements upon which the potential object is based defining the likelihood that the set of readings correspond to an actual object of that predefined shape. Each potential object is then assumed to have the predefined shape that yielded the lowest metric (i.e., that yielded the metric that indicates the highest likelihood that the object has the corresponding shape). The list of potential objects is then ordered according by their calculated metrics from lowest to highest. The ordered list is then pared down to a smaller list of actual objects by selecting the potential object highest on the ordered list and assuming that it is an actual object and then removing from the list all other lower-ordered potential objects that are based on any of the individual measurements upon which the selected object is based and repeating this process until all potential objects on the list have either been selected as an actual object or removed from the list.

Claims37

Dependent claims

A method of determining the approximate shapes, sizes and locations of one or more objects based on range measurements of a plurality of range sensors, said method comprising the steps of:

(1) obtaining from said sensors a plurality of range measurements;
(2) correlating said range measurements of said plurality of sensors to generate a list of potential objects, each of said objects being based on a plurality of range measurements;
(3) for each potential object on said list, calculating a plurality of locations of said object assuming said object has a plurality of predefined shapes, wherein each of said calculated locations of said plurality of locations corresponds to one of the predefined shapes of said plurality of predefined shapes;
(4) for each potential object, calculating an error metric for each of said calculated locations, said error metrics indicative of a difference between said corresponding calculated location of said object and said range measurements upon which said object is based;
and
(5) for each potential object on said list, determining that said potential object has the shape corresponding to the lowest error calculated in step (4).

3 more elements

A method of determining the approximate shapes, sizes and locations of one or more objects based on range measurements from a plurality of range sensors, said method comprising the steps of:

(1) obtaining from said sensors a plurality of range measurements;
(2) correlating said range measurements of said plurality of sensors using trilateration to generate a list of objects, each of said objects being based on a set of range measurements;
(3) for each object on said list, calculating a first location of said object assuming said object is a circle of a first predefined radius;
(4) for each object on said list, calculating a second location of said object assuming said object is a circle of a second predefined radius;
(5) for each object, calculating an error metric for each of said first and second locations, said error metrics indicative of a difference between said corresponding calculated location of said object and said range measurements upon which said object is based;
and (6) for each object on said list, determining that said object has the radius that yielded the lowest error in step (5).

3 more elements

An apparatus for determining the locations of a plurality of actual objects based on range measurements said apparatus comprising:

a plurality of range sensors, each sensor capable of providing a multiplicity of range measurements;
a digital processor adapted to (a) obtain from said sensors a plurality of range measurements;
(b) correlates said range measurements of said plurality of sensors to generate a list of potential objects, each of said objects being based on a plurality of range measurements;
(c) for each potential object on said list, calculate a plurality of locations of said object assuming said object has a plurality of predefined shapes, respectively;
(d) for each potential object, calculate an error metric for each of said calculated locations, said error metrics indicative of a difference between said corresponding calculated location of said object and said range measurements upon which said object is based;
and (e) for each potential object on said list, determining that said potential object has the shape corresponding to the lowest error.

3 more elements

Dependencies are inferred from the claim text.

Method and apparatus for identifying complex objects based on range readings from multiple sensors

Life of this patent

Method and apparatus for identifying complex objects based on range readings from multiple sensors

Life of this patent

Abstract

Claims37