Most volume modelling systems are very limited in the complexity of the surfaces which they support. This is satisfactory for basic models of most mechanical components, since the functional surfaces are not usually complex. However, there are often blends between simple base surfaces. This paper presents a technique appropriate for blend definition and profile control. A discussion of blend conics is used to develop analogous surfaces for use in typical volume modelling systems. These surfaces are then used to set theoretically define bounded volumes for fillets and chamfers. Empirical results show that the method described suits many engineering applications.

Abstract This paper gives the rationale for the design of a nucleus to support real time control applications. In particular, mechanisms for communication between concurrent tasks are reviewed and analysed in the context of this application area. Finally, although no implementation is discussed in detail, techniques which have proved useful in implementing this nucleus on three different machines are described.