133 research outputs found
Recommended from our members
Smooth parametric surfaces and n-sided patches
The theory of 'geometric continuity' within the subject of CAGD is reviewed. In particular, we are concerned with how parametric surface patches for CAGD can be pieced together to form a smooth Ck surface. The theory is applied to the problem of filling an n-sided hole occurring within a smooth rectangular patch complex. A number of solutions to this problem are surveyed
Shape characterisation of tool path motion
For a given application, the autonomous regulation of tool path motion by a machine’s controller can produce undesirable and unknown machining conditions. Machining parameters may therefore require a posteriori optimisation. Indeed, the methods employed are often iterative and informed by empirical evidence from machining trials.
A shape characterisation of tool path motion is postulated by enforcing constraints on the kinematic equations describing velocity, acceleration and jerk. The resulting description of motion depends only upon the kinematic limits of a machine and the intrinsic shape properties of a tool path.
The resulting shape schematics provide complete illustrations of the distinctive features of each of the kinematic vectors. Kinematic profiles, derived from a series of test tool path motions are compared with these shape schematics in order to provide supportive empirical evidence.
The main contribution of this thesis is to demonstrate a priori shape characterisation of tool path motion. This characterisation is achieved without knowledge of the motion control algorithms implemented by a given machine’s controller. The characterisation may be employed to inform the selection of machining parameters and thereby reduce the time and the number of machining trials
- …