A hand tool device comprises a computing unit and at least one locating device configured to receive two orthogonal polarization directions of at least one reflected locating signal. The computing unit is configured to determine, from two received polarization directions of the reflected locating signal, an item of orientation information of a concealed, elongate object.

Locating a moving magnetic object includes determining its position or orientation from measurements from an array N tri-axial magnetometers (N>5) mechanically linked to one another with 0-DOF by repeatedly estimating its position relative to the array from measurements made either in a preceding iteration or from a sensor distinct from the array's magnetometers before making a new measurement using the array's magnetometers; computing the distance between each magnetometer and the object's estimated position; eliminating Ni magnetometers closest to this estimated position, where Ni<N; using the remaining magnetometers, making a new measurement of the field generated or modified by the object; and determining its new position or orientation from the new measurements so as to obtain the object's new location.

Locating a moving magnetic object includes determining its position or orientation from measurements from an array N tri-axial magnetometers (N>5) mechanically linked to one another with 0-DOF by repeatedly estimating its position relative to the array from measurements made either in a preceding iteration or from a sensor distinct from the array's magnetometers before making a new measurement using the array's magnetometers; computing the distance between each magnetometer and the object's estimated position; eliminating Ni magnetometers closest to this estimated position, where Ni<N; using the remaining magnetometers, making a new measurement of the field generated or modified by the object; and determining its new position or orientation from the new measurements so as to obtain the object's new location.

A displacement sensor measures capacitance between a rotor-stator pair. The displacement sensor includes a plurality of stators coupled to a first object. The plurality of stators is oriented parallel to an axis of motion between the first object and a second object. The displacement sensor further includes a plurality of rotors coupled to the second object. The plurality of rotors is oriented parallel to the axis of motion. Each rotor of the plurality of rotors is aligned with and configured to receive a corresponding stator of the plurality of stators to create a respective rotor-stator pair. Capacitance between the rotor-stator pairs change as a function of position of the first object relative to the second object along the axis of motion. An amount of displacement of the first object relative to the second object is determined based in part on the capacitance values.

Embodiments are directed to apparatuses, methods and systems for tracking usage of an item. In one scenario, a microcontroller is configured to send a periodic signal over electrical traces that are distributed over an item to determine whether a change in electrical throughput has occurred in a trace. Upon determining that such a change has occurred, an indication is generated that describes the type of usage that occurred and the time at which the use occurred. An indication of the type of usage and the time of occurrence is then provided to specified recipients. Apparatuses for tracking such usage include a battery, a microprocessor, a transmitter and capsules for storing the controlled substances. Each capsule has an electrical trace extending through at least some of the capsule. The microprocessor is configured to determine, using the electrical traces, which capsules have been opened by identifying which traces have been broken.

A localization scheme and method using a laser sensor for indoor wheeled mobile robots (IWMR), which need to localize themselves for working autonomously, is provided. In this method, a laser sensor moves inside an onboard guide way and its distance measurements are used to robustly detect and recognize a unique target based on edge detection and pattern recognition techniques. From the distance measurements with respect to the recognized target, a kinematic model is developed to determine the IWMR orientation and location in the global co-ordinates (in 2-D). Such target recognition and localization methods are validated with experimental results.

A localization scheme and method using a laser sensor for indoor wheeled mobile robots (IWMR), which need to localize themselves for working autonomously, is provided. In this method, a laser sensor moves inside an onboard guide way and its distance measurements are used to robustly detect and recognize a unique target based on edge detection and pattern recognition techniques. From the distance measurements with respect to the recognized target, a kinematic model is developed to determine the IWMR orientation and location in the global co-ordinates (in 2-D). Such target recognition and localization methods are validated with experimental results.

The invention relates to a method for compensating a magnetic locator in the presence of a magnetic-field-disturbing material, comprising: an emitter (10) comprising at least one coil emitting an emission magnetic field; a receiver (20) comprising at least one receiving coil and a device providing a plurality of measurements Ip.sub.i of a receiving magnetic field induced by the emission field in each receiving coil; and a processing unit (25) comprising a field model allowing the calculation of a position (P) and/or an orientation (Q) of the receiver by means of calculation of a prediction H.sub.i of the measurements according to a criterion (C) calculated according to an error E.sub.i which is itself calculated in relation to the measurements Ip.sub.i. The invention is characterised in that the error E.sub.i is calculated by successive iterations from initial values prescribed by the prediction H.sub.i as being the difference between the measurements Ip.sub.i and a disturbed model Hp.sub.i, according to the equation E.sub.i=Ip.sub.i−Hp.sub.i, the disturbed model Hp.sub.i satisfying Hp.sub.i=H.sub.i+P.sub.i (α.sub.i=−arctan(βω.sub.i), (I) the parameter β being identical for all of the measurements Ip.sub.i, the calculation being carried out in such a way as to minimise the criterion C.

A method and apparatus is disclosed for allowing a magnetic tracking system to detect, and operate in close proximity in the same physical environment with, additional magnetic tracking systems. The first user's magnetic tracking system that becomes active in the physical space becomes the master system, and assigns time slots for its own transmitting antennas to generate the magnetic field which is used to determine the position and orientation of the user's limbs relative to the user's head. The master system also determines when other magnetic tracking systems become active in the physical space and assigns to those systems identification codes and time slots for their transmitting antennas to generate a magnetic field so that the position and orientation of the user's hands relative to the user's head for each of those systems may be determined. By requiring each magnetic tracking system to operate in different time slots, there is no interference between the systems.

A method and apparatus is disclosed for allowing a magnetic tracking system to detect, and operate in close proximity in the same physical environment with, additional magnetic tracking systems. The first user's magnetic tracking system that becomes active in the physical space becomes the master system, and assigns time slots for its own transmitting antennas to generate the magnetic field which is used to determine the position and orientation of the user's limbs relative to the user's head. The master system also determines when other magnetic tracking systems become active in the physical space and assigns to those systems identification codes and time slots for their transmitting antennas to generate a magnetic field so that the position and orientation of the user's hands relative to the user's head for each of those systems may be determined. By requiring each magnetic tracking system to operate in different time slots, there is no interference between the systems.