Abstract: A three-dimensional non-contacting angular motion sensor, based on magnetometry, has been developed for velocity feedback in the ball wheel mechanism, which serves as the drivetrain for a class of omnidirectional mobile platforms. More generally, this scheme tracks rigid-body rotation about a fixed point with an undefined axis of rotation. The approach involves tracking the time-varying magnetic field of a permanent disc magnet, embedded at the center of the sphere. This data is then used to determine the absolute orientation of the magnet axis. Finally, an approach based on the natural invariants of rigid-body motion is used to determine the instantaneous axis of rotation and the angular speed of the sphere about this axis.

Abstract: Apparatus and methods for applying heated sealants, such as molten polymeric material, to surfaces such as for filling cracks in pavement surfaces. Aspects of the invention include block cutting assembly, heated dispensing hose, and crack filling applicator head. By way of example, the block cutting assembly comprises a ram device for driving sealant blocks against a heated cutting member which severs the blocks to speed liquefaction within the heated sealant chamber. An associated enclosure incorporates a loading door preferably configured for operation in response to the position of the ram device. The heated dispensing hose may comprise a heating element running through the interior of the hose to heat sealants as they pass through the hose. The crack filling applicator head comprises a dispensing tube upon which a sealing chamber is coupled for retaining a quantity of liquid sealant proximal to the pavement surface being filled.