Automatic Generation of Gouge - free and Angular - velocity - compliant 5 - axis Toolpath ( Revised )

Existing works in automatic generation of interference-free 5-axis surface machining toolpaths bear a serious drawback – in order to avoid the obstacles, the tool is often required to make drastic change in its orientation between neighboring contact points. Such quick change in tool’s orientation can never be made possible in reality due to the stringent physical limit on the speed and acceleration of the rotary motions of the machine tool. The usual ad-hoc solution to this problem is to smooth the toolpath in the configuration space, which though is prone to special situations of failure and is not able to guarantee the absolute compliance with the given angular velocity limit. In this paper we present an approach to this problem by directly involving the angular velocity limit in the search process. The presented algorithm will automatically generate a 5-axis toolpath that not only is interference-free but also guarantees the angular-velocity compliance. Delicate computation and manipulation of visibility maps and their derivative data ensure that the proposed algorithm is computationally feasible with acceptable computing time and memory requirement. Test examples are given to demonstrate the promising use of the proposed solution.