Mechanical vibration on mobile hard disk is inevitable in the practical usage, and violent vibration may cause disk slip with significant position error, which will degrade the servo control performance, prolong time to ready (TTR) of servo and lower reading and writing speed of the magnetic head. The servo tracking accuracy of hard disk drive actuator with respect to various mechanical disturb...

This application note focuses on a design based on National Semiconductor’s patented NeuFuz based neural-fuzzy technology to arrive at a slip control scheme implemented on National Semiconductor’s low-cost COP8TM microcontroller. NeuFuz technology allows for the automated generation of a fuzzy logic control engine based on training data. In this case, the training data was taken from the well k...

Six-wheel drive (6WD) articulated dump truck has excellent passing ability and high productivity, but its stability should be improved. A dynamic model of 6WD articulated vehicle with 3 degree-of-freedom (DOF) is established. With the control variables of yaw velocity and side-slip angle at mass center of front body, a feedfoward-feedback control system is designed by linear quadratic regulator...

This paper presents the movement dynamic of the train and the relationship between the speed of wheel and train, as well as a discussion about the concept of wheel slip. There are two different operation regions designated as creep and wheelspin areas for wheel slip. Creep and wheelspin areas have stable and unstable characteristics, respectively. Wheels and rails are constructed from iron, and...

Stick-slip vibrations present at the bottom hole assembly (BHA) of a generic oilwell drillstring subject to dry friction are studied. Different nonlinear differential equations-based models of a drillstring are analyzed. The drillstring models presented are oriented to avoid simulation problems due to the discontinuities originated by the presence of dry friction. The influence of different dri...

Background A non-contrast 4D Time-Spatial Labeling Inversion Pulse (Time-SLIP) technique [1,2] (3D acquisition and time) has been developed to investigate myocardial bloodflow on healthy volunteers without administration of contrast materials. The technical differences are discussed between our 4D Time-SLIP using tagging aortic root and Flow-sensitive Alternating inversion recovery (FAIR) using...

This paper describes the results of two experiments that investigate relative motion between a surface and the fingertip (slip) as part of a larger program of research on “fingertip haptics.” The primary intent of both experiments is to evaluate the importance of relative motion with respect to perceiving surface velocity. The perception of surface velocity is crucial to dexterous control and o...

During earthquakes, comminution and frictional heating both contribute to the dissipation of stored energy. With sufficient dissipative heating, melting processes can ensue, yielding the production of frictional melts or "pseudotachylytes." It is commonly assumed that the Newtonian viscosities of such melts control subsequent fault slip resistance. Rock melts, however, are viscoelastic bodies, ...

Enabled by a technology to fabricate well-defined nanogrates over a large area 2 2 cm2 , we report the effect of such a surface, in both hydrophilic and hydrophobic conditions, on liquid slip and the corresponding friction reduction in microchannels. The grates are designed to be dense 230 nm pitch but deep 500 nm in order to sustain a large amount of air in the troughs when the grates are hydr...

Currently grip control during in-hand manipulation is usually modeled as part of a monolithic task, yielding complex controllers based on force control specialized for their situations. Such non-modular and specialized control approaches render the generalization of these controllers to new in-hand manipulation tasks difficult. Clearly, a grip control approach that generalizes well between seve...