Metrotech Corporation

Optimal Ranging, Inc.

Tokyo Electron Limited

US Government As Represented by the Secretary of the Army

James W Waite

Dimitar Gargov

Thorkell Gudmundsson

Michail Konstantinos Tsatsanis

Sunil C Shah

Mark Alan Erickson

Ioannis Kanellakopoulos

Johan D Overby

Ming Gu

Cecilia Gabriela Galarza

Kun Li

Daniel Joseph Hernandez

Johan Överby

Norman Man Leung Yuen

John Josef Hench

Gurcan Aral

David Mark Hull

Thomas E Par&eacute;, Jr

Ruwan Welaratna

Ross N Adelman

Thomas E Paré, Jr

Di Lin

Fernando Lopez-de-Victoria

Heberly Rosario

In accordance with aspects of the current invention, a method of determining a location of a utility line includes driving one or more transmitters with a continuous wave signal; either adjusting for effects of direct coupling between the transmitters and one or more sensors mounted on the same rigid platform or different platforms or maintaining sufficient separation between a transmitter platform and a sensor platform to minimize such effects; and deriving a position of the line relative to the sensors from the measurements.

Method and apparatus for simultaneous inductive excitation and locating of utilities

A locating system is presented. In some embodiments, the locating system includes a first platform, the first platform including a transmitter capable of inducing a current in a line; a second platform, the second platform including a receiver capable of detecting the current in the line; and a processor coupled to the first platform and the second platform, the processor directing the first platform and the second platform to control their motion over the line and collecting location data of the line.

A system and method for estimating the magnitude and phase of magnetic and electrical currents in a power line comprising at least one processor operating to create a model of the power line and derive expected complex magnetic and electric-field values; at least one memory; at least one sensor positioned proximate to the at least one power line for sensing and providing measurements of the magnetic and electric fields of the at least one power line; the at least one processor operating to compute a set of complex magnetic and electric field values based upon the measurements provided by the at least one sensor and to estimate parameters related to the complex voltage and/or current of the at least one power line based upon the measured field values and the set of expected complex electric current and voltage values derived from a model of at least one power line.

Method and apparatus for power quality and synchrophasor monitoring on power lines

A system and method for providing autonomous navigation for an Autonomous Vehicle such as an Unmanned Air Vehicle (UAV) or an Autonomous Underwater Vehicle (AUV) in the vicinity of power lines or other signal carrying lines or underwater cable is presented. Autonomous navigation is achieved by measuring the magnitude and phase of the electromagnetic field at an unknown location within a space under excitation by a set of power cables of the power line with one or more orthogonal electromagnetic sensors formed on the AV; and estimating parameters related to a position and orientation of the AV, and load parameters of each cable based on the residual error between the measured set of complex electromagnetic field values corresponding to a combined model of the set of power cables.

Autonomous vehicle power line position and load parameter estimation

A system for determining the position of an underground sonde transmitter is disclosed. In some embodiments, the system measures a set of complex electromagnetic field magnitude and phase strengths at one or more positions while traversing a target sonde path at any angle using one or more electromagnetic coil sensors, models a set of expected complex electromagnetic strengths of a hypothetical sonde at the positions for one or more of the electromagnetic coil sensors, the set of expected electromagnetic field values corresponding to a model for the target sonde, and estimates parameters related to the target sonde based on the residual error between the measured set of complex electromagnetic field values and the modeled set of expected complex electromagnetic field strengths. A final estimated parameter set is determined after the residual error has converged to a minimum tolerance to indicate the sonde transmitter position.

System for determining a precise location and orientation of a concealed dipole transmitter

A method for determining the location and orientation of a transmitter object by measuring a set of complex electromagnetic field magnitude and phase strengths within a space using one or more receivers is provided. The method includes modeling a set of expected complex electromagnetic strengths to estimated position and orientation of the transmitter object. And estimating parameters related to the transmitter object position based on the residual error between the measured set of complex electromagnetic field values and a set of expected electromagnetic field values. Further embodiments include a method as above including a plurality of receivers with known positions within a limited space including the transmitter object. A sensor network including a plurality of receivers to perform the above method is also provided. The receivers may communicate using a wireless channel.

Precise positioning using a distributed sensor network

A system and method for providing autonomous navigation for an Unmanned Air Vehicle (UAV) in the vicinity of power lines is presented. Autonomous navigation is achieved by measuring the magnitude and phase of the electromagnetic field at an unknown location within a space under excitation by a set of power cables of the power line with one or more orthogonal electromagnetic sensors formed on the UAV; modeling a set of expected complex electromagnetic strengths of the set of power cables at the currently estimated position and orientation of the UAV based on a model of the set of power cables; and estimating parameters related to a position and orientation of the UAV, and load parameters of each cable based on the residual error between the measured set of complex electromagnetic field values and the set of expected electromagnetic field values corresponding to a combined model of the set of power cables.

UAV power line position and load parameter estimation

A method for determining the location of an underground sonde transmitter is disclosed. In some embodiments, the method includes measuring a set of complex electromagnetic field magnitude and phase strengths at one or more of positions while traversing a target sonde path at any angle using one or more electromagnetic coil sensors, modeling a set of expected complex electromagnetic strengths of a hypothetical sonde at the one or more of positions for one or more of the electromagnetic coil sensors, the set of expected electromagnetic field values corresponding to a model for the target sonde, and estimating parameters related to the target sonde based on the residual error between the measured set of complex electromagnetic field values and the modeled set of expected complex electromagnetic field strengths, wherein a final estimated parameter set is determined after the residual error has converged to a minimum tolerance.

Precise location and orientation of a concealed dipole transmitter

Line locator systems that fuse traditional sensors used in a combined pipe and cable locator (electromagnetic coils, magnetometers, and ground penetrating radar antennas) with low cost inertial sensors (accelerometers, gyroscopes) in a model-based approach are presented. Such systems can utilize inexpensive MEMS sensors for inertial navigation. A pseudo-inertial frame is defined that uses the centerline of the tracked utility, or an aboveground fixed object as the navigational reference. An inertial sensor correction mechanism that limits the tracking errors over time when the model is implemented in state-space form using, for example, the Extended Kalman Filter (EKF) is disclosed.

Sensor fusion for model-based detection in pipe and cable locator systems

An electronic marker locator with a digital architecture for providing accurate and consistent estimation of the signal strength is presented. The marker locator includes a Digital Phase-Locked Loop (DPLL) structure. The electronic marker locator transmits known and adjustable frequency bursts corresponding to the markers to be located while synchronously capturing the signals returned from the markers. Because of the convergence properties of the DPLL, very consistent measurements of the reflected marker signal field strength are possible, resulting in both an improvement of maximum detection depth and depth accuracy. Further, the analog front-end hardware can be reduced, offering wider resistance to component tolerances, lower calibration and test times, and flexible frequency selectivity.

Method and apparatus for digital detection of electronic markers using frequency adaptation

An electronic marker locator with a digital architecture for providing accurate and consistent estimation of the signal strength is presented. The marker locator includes a Digital Phase-Locked Loop (DPLL) structure. The electronic marker locator transmits known and adjustable frequency bursts corresponding to the markers to be located while synchronously capturing the signals returned from the markers.

A locator capable of tracking buried, non-metallic utility lines (fiber optic, gas, water, waste, conduits) using ground penetrating radar (GPR) and an inertial position sensor is described. In some embodiments, a tracking filter is applied to a hyperbolic trajectory model based on the radar range data to determine a predicted track of the target utility line. After comparison of the predicted track to the measured inertial position, the centerline variance of the tracked line can be deduced. In some embodiments, an electromagnetic pipe and cable locator may also be included. Some embodiments of the invention can include accurate depth calibration and line depth tracking. Further, a display may provide results to a user in a simplified fashion.

Centerline and depth locating method for non-metallic buried utility lines

A new digital architecture for metallic pipe and cable locators, providing accurate estimation of the fundamental locate parameters, electromagnetic signal strength and signal direction, and utilizing a nested Digital Phase-Locked Loop (DPLL) structure is disclosed. The obstacles to signal direction measurement in low SINR environments using the signal select method are overcome and a more precise phase comparison between the carrier and the FM modulation signals is obtained. The architecture further significantly reduces analog front-end hardware requirements, offers wider resistance to component tolerances, lower calibration and test time, and provides flexible frequency selectivity. Locators according to the present invention provide accurate estimation of the fundamental physical parameters of line location (electromagnetic signal strength and signal direction) in extremely noisy environments, using Digital Signal Processing (DSP) methods.

Method and apparatus for digital detection of electromagnetic signal strength and signal direction in metallic pipes and cables

A method that sends upstream a collection of data samples measured from a DSL line.

Method and apparatus for cooperative diagnosis of impairments and mitigation of disturbers in communication systems

A method and apparatus for identification of interference sources are disclosed.

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Los Gatos, CA, United States of America

James W Waite