Modelling of non-steady-state transition from single-point to two-point rolling contact

Transistors – From Point Contact to Single Electron

The first solid state electron device was the metal-semiconductor rectifier discovered by Ferdinand Braun in 1874 even before the discovery of the electron! He found that mercury metal contacts on copper or iron sulphide gave non-linear currentvoltage characteristics. In 1904 J C Bose obtained a U.S patent for point contact rectifiers on Galena (PbS). He found that the direction of rectificatio...

Single Point Contact Measurements of Mechanical Resonances

In this paper we present a novel technique for measuring the material properties of spherical objects. The technique is also capable of detecting the presence of surface defects in these objects. We excite resonances of spheres at both low and high frequencies. Resonances are generated by forming a one-point Hertzian contact between the sphere and a spherical depression in a buffer rod with a t...

Pseudo contact point monitoring for contact state estimation

Contact state information is indispensable for performing skillful tasks in which an end-effector should be in contact with the environment. In previous work, the authors introduced the concept of a pseudo contact point that is useful for tasks involving contact as one expression of the contact state. In this paper, an extended definition of the pseudo contact point is proposed. The pseudo cont...

Simulation of Soft Finger Contact Model with Rolling Effects in Point-Contact Haptic Interfaces

Computation of contact point trajectories and forces exchanged between two bodies in contact are relevant to several disciplines. The solutions proposed in the literature are often too complex to be implemented in real time simulations, especially if rolling effects are considered. In this chapter, an algorithm for fast simulation of softfinger contact model with rolling effects is proposed. Th...

Point of Contact