Abstract: A system and method for conformal alignment of an aircraft-based head worn display (HWD) system defines far-field features in view of the HWD display, each far-field feature having a 3D truth position in a navigational reference frame. The aircraft GPS/IRS determines pointing vectors to each feature in the aircraft reference frame. The HWD user estimates a nominal head pose for orienting the far-field features in the HWD display, and the HWD system renders the far-field features based on the nominal head pose and pointing vectors. The rendered far-field features are aligned to their real-world 3D truth positions (either manually or with the assistance of witness cameras) and a latched pose of the HWD headtracker system determined based on a successful alignment within accuracy bounds. Based on the latched headtracker pose, the HWD headtracker alignment and the alignment of the HWD display reference frame to the aircraft reference frame are updated.

Abstract: A surgical system or assembly for performing cardiac surgery includes a surgical instrument; a servo-mechanical system engaged to the surgical instrument for operating the surgical instrument; and an attachment assembly for removing at least one degree of movement from a moving surgical cardiac worksite to produce a resultant surgical cardiac worksite. The surgical system or assembly also includes a motion tracking system for gathering movement information on a resultant surgical cardiac worksite. A control computer is engaged to the attachment assembly and to the motion tracking system and to the servo-mechanical system for controlling movement of the attachment assembly and for feeding gathered information to the servo-mechanical system for moving the surgical instrument in unison with the resultant surgical cardiac worksite such that a relative position of the moving surgical instrument with respect to the resultant surgical cardiac worksite is generally constant.

Abstract: A surgical system or assembly for performing cardiac surgery includes a surgical instrument; a servo-mechanical system engaged to the surgical instrument for operating the surgical instrument; and an attachment assembly for removing at least one degree of movement from a moving surgical cardiac worksite to produce a resultant surgical cardiac worksite. The surgical system or assembly also includes a motion tracking system for gathering movement information on a resultant surgical cardiac worksite. A control computer is engaged to the attachment assembly and to the motion tracking system and to the servo-mechanical system for controlling movement of the attachment assembly and for feeding gathered information to the servo-mechanical system for moving the surgical instrument in unison with the resultant surgical cardiac worksite such that a relative position of the moving surgical instrument with respect to the resultant surgical cardiac worksite is generally constant.

Abstract: A surgical system or assembly for performing cardiac surgery includes a surgical instrument; a servo-mechanical system engaged to the surgical instrument for operating the surgical instrument; and an attachment assembly for removing at least one degree of movement from a moving surgical cardiac worksite to produce a resultant surgical cardiac worksite. The surgical system or assembly also includes a motion tracking system for gathering movement information on a resultant surgical cardiac worksite. A control computer is engaged to the attachment assembly and to the motion tracking system and to the servo-mechanical system for controlling movement of the attachment assembly and for feeding gathered information to the servo-mechanical system for moving the surgical instrument in unison with the resultant surgical cardiac worksite such that a relative position of the moving surgical instrument with respect to the resultant surgical cardiac worksite is generally constant.

Abstract: A method for measuring the temperature-compensated change in the height of a surface of a liquid. The method positions an acoustic signal transducer for emitting and receiving acoustic signals below the surface of the liquid, positions a quasi-static reference device with a fiducial such that the fiducial lies within a predetermined range below the surface of the liquid, and positions one or more fiducials below the surface of the liquid to establish points separated by known distances. The transducer emits acoustic signals, and receives their reflections. The travel times of the reflections from the liquid surface and the fiducials are used to calculate changes in travel times during the measurement period, to estimate the speed of sound in the liquid, to correct for temperature-induced changes in the travel times, and to obtain a temperature-compensated change in travel time to the liquid surface.

Abstract: An apparatus for measuring liquid levels and leak rates in a storage tank, using an acoustic transducer and a quasi-static reference device that positions an acoustic target within a predetermined distance range below the surface of the liquid.

Abstract: The piston displacement apparatus and method for detection of leaks in pressurized pipelines disclosed herein measures volume changes at different pressures to determine thermally compensated leak rates. The apparatus uses a piston displacement apparatus to precisely determine volume changes.

Abstract: The apparatus and method for detection of leaks in pressurized pipelines disclosed herein measures thermally compensated leak rates. The apparatus uses an acoustic sensor and fiducial reference system to precisely determine leak rates.

Abstract: The gas pressure control apparatus and method for detection of leaks in pressurized pipelines disclosed herein measures thermally compensated leak rates. The apparatus uses a pressure vessel and gas pressure control system to precisely determine leak rates.

Abstract: Methods for measuring liquid levels and leak rates in a storage tank, using an acoustic transducer and a quasi-static reference device that positions an acoustic target within a predetermined distance range below the surface of the liquid. A method for measuring the height of the surface of a liquid, i.e., liquid level.

Abstract: The positive-displacement pump apparatus and method for detection of leaks in pressurized pipelines disclosed herein measures volume changes at different pressures to determine thermally compensated leak rates. The apparatus uses a positive-displacement pump apparatus to precisely determine volume changes.

Abstract: A method of determining the presence and temperature compensated volumetric flow rate of leaks in fluid pressurized pipelines. The pipeline is maintained at a first pressure and the fluid volume change per unit time is calculated. The pressure is then maintained at a second different pressure and a second fluid volume change per unit time is calculated. The system is then maintained at the first pressure while a third fluid volume change per unit time is calculated. The first and third rates are combined with the second rate to obtain a temperature compensated leak volumetric flow rate.

Abstract: A tube vertically disposed in a liquid storage tank, in which the tube has a cross-sectional area which changes with height in proportion to the variation in the tank's cross-sectional area. The tube is filled through an open valve near the bottom of the tube and the valve is closed for the remainder of the test. Other valves above the liquid level are kept open to maintain equal vapor pressures in the tank and the tube. A first sensor measures the fluid level in the tank, while a second sensor measures the differences in fluid levels between tank and tube over a period of time. Ambient height changes are identical for liquid in both tank and tube, whereas leak related height changes occur only in the tank. A second identical tube may be provided when levels are affected by the tube or sensor, or when the tube is required to hold the sensor and is open to the tank.