Abstract: A method for accurately synthesizing a full-aperture data map from a series of overlapped sub-aperture data maps. In addition to conventional alignment uncertainties, a generalized compensation framework corrects a variety of errors, including compensators that are independent in each sub-aperture. Another class of compensators (interlocked) include coefficients that are the same across all the sub-apertures. A constrained least-squares optimization routine maximizes data consistency in sub-aperture overlap regions. The stitching algorithm includes constraints representative of the accuracies of the hardware to ensure that the results are within meaningful bounds. The constraints also enable the computation of estimates of uncertainties in the final results. The method therefore automatically calibrates the system, provides a full-aperture surface map, and an estimate of residual uncertainties.

Abstract: A method for accurately synthesizing a full-aperture data map from a series of overlapped sub-aperture data maps. In addition to conventional alignment uncertainties, a generalized compensation framework corrects a variety of errors, including compensators that are independent in each sub-aperture. Another class of compensators (interlocked) include coefficients that are the same across all the sub-apertures. A constrained least-squares optimization routine maximizes data consistency in sub-aperture overlap regions. The stitching algorithm includes constraints representative of the accuracies of the hardware to ensure that the results are within meaningful bounds. The constraints also enable the computation of estimates of uncertainties in the final results. The method therefore automatically calibrates the system, provides a full-aperture surface map, and an estimate of residual uncertainties.

Abstract: A method and apparatus for finishing a workpiece surface using MR fluid is provided wherein the workpiece is positioned near a carrier surface such that a converging gap is defined between a portion of the workpiece surface and the carrier surface; a magnetic field is applied substantially at said gap; a flow of stiffened MR fluid is introduced into said converging gap such that a work zone is created in the MR fluid to form a sub-aperture transient finishing tool for engaging and causing material removal at the portion of the workpiece surface; and the workpiece or the work zone is moved relative to the other to expose different portions of the workpiece surface to the work zone for predetermined time periods to selectively finish said portions of said workpiece surface to predetermined degrees.

Abstract: A fluid having magnetorheological (MR) properties and including a finely-divided abrasive material is directed through a non-ferromagnetic nozzle disposed axially of the helical windings of an electric solenoid. The MR fluid may contain magnetosoft or magnetosolid particles or mixtures thereof. A magnetic field created by the solenoid orients and aligns the magnetic moments of the particles to form fibrils thereby stiffening the flowing MR fluid which, when ejected from the nozzle, defines a highly-collimated jet. Collimation of the MR material persists for a significant time outside the magnetic field, permitting use of the abrasive jet to shape and/or polish the surface of a workpiece at some distance from the nozzle. The jet is directed into a shroud against a workpiece mounted for multiple-axis rotation and displacement to meet predetermined material removal needs for shaping. The solenoid may be similarly mounted to also move the jet over the surface of the workpiece.

Abstract: An improved system for increasing the effectiveness of magnetorheological finishing of a substrate. An inline flowmeter is close-loop linked to the rotational speed of a pressurizing pump to assure that the flow of magnetorheological fluid (MRF) to the work zone is constant. A simplified capillary viscometer is disposed in the fluid delivery system at the exit thereof onto the wheel surface. Output signals from the flowmeter and the viscometer pressure sensor are sent to a computer which calculates the viscosity of MRF being delivered to the work zone and causes replenishment of carrier fluid to the work-concentrated MRF to return the viscosity to aim to assure that a constant concentration of magnetic solids is being provided to the work zone.

Abstract: A method and apparatus for finishing a workpiece surface using MR fluid is provided wherein the workpiece is positioned near a carrier surface such that a converging gap is defined between a portion of the workpiece surface and the carrier surface; a magnetic field is applied substantially at said gap; a flow of stiffened MR fluid is introduced into said converging gap such that a work zone is created in the MR fluid to form a sub-aperture transient finishing tool for engaging and causing material removal at the portion of the workpiece surface; and the workpiece or the work zone is moved relative to the other to expose different portions of the workpiece surface to the work zone for predetermined time periods to selectively finish said portions of said workpiece surface to predetermined degrees.

Abstract: A magnetorheological fluid comprises non-colloidal magnetic particles, an abrasive, water, glycerol, and an alkaline buffer. The abrasive may be CeO.sub.2, the non-colloidal magnetic particles may be carbonyl iron, and the alkaline buffer may be Na.sub.2 CO.sub.3. The fluid is useful for magnetorheological finishing.

Abstract: A method and apparatus for finishing a workpiece surface using MR fluid is provided wherein the workpiece is positioned near a carrier surface such that a converging gap is defined between a portion of the workpiece surface and the carrier surface; a magnetic field is applied substantially at said gap; a flow of stiffened MR fluid is introduced into said converging gap such that a work zone is created in the MR fluid to form a sub-aperture transient finishing tool for engaging and causing material removal at the portion of the workpiece surface; and the workpiece or the work zone is moved relative to the other to expose different portions of the workpiece surface to the work zone for predetermined time periods to selectively finish said portions of said workpiece surface to predetermined degrees.