초록 ▼

Methods and apparatus for position/orientation tracking within a bounded volume employ at least one stationary sensor, called a "witness sensor," having a fixed position and orientation near or within the volume to account for electromagnetic distortion. One or more probe sensors are placed on an ob

Methods and apparatus for position/orientation tracking within a bounded volume employ at least one stationary sensor, called a "witness sensor," having a fixed position and orientation near or within the volume to account for electromagnetic distortion. One or more probe sensors are placed on an object to be tracked within the volume, and the output of each witness sensor is used to compute the parameters of a non-real effective electromagnetic source. The parameters of the effective source are used as inputs to the computation of position and orientation as measured by each probe sensor, as if the object were in the non-distorted electromagnetic field produced by the effective source or sources. In addition to trackers for helmet-mounted displays in aircraft, tank, and armored-vehicle applications, the invention finds utility in any electromagnetic tracking system which might be subject to electromagnetic distortion or interference. Such application areas include electromagnetic motion capture systems, and medical systems and instruments, among others.

대표청구항 ▼

1. Apparatus for determining the position and orientation of an object within a bounded volume of interest in the presence of electromagnetic distortion, the apparatus comprising:a real source of an electromagnetic field having measurable magnetic induction-vector components; one or more stationary

1. Apparatus for determining the position and orientation of an object within a bounded volume of interest in the presence of electromagnetic distortion, the apparatus comprising:a real source of an electromagnetic field having measurable magnetic induction-vector components; one or more stationary witness sensors supported near or within the volume of interest, each witness sensor being operative to measure the induction-vector components using a fixed known position and orientation; one or more probe sensors supported on the object for measuring the induction-vector components; and a processor in communication with each witness sensor and each probe sensor, the processor being operative to perform the following functions: a) compute the characteristics of at least one effective electromagnetic source, the effective source being defined as a model source which would produce the field in the vicinity of each witness sensor similar, or identical, to the field generated by the real source, along with electromagnetic distortion present in the volume, b) receive the induction-vector components measured by each probe sensor, and c) compute the position and orientation of the object by applying the spatial and electromagnetic magnetic characteristics of the effective source to the induction-vector components measured by each probe sensor.