Compensation of thermal deformation of a hybrid parallel kinematic machine

Many different Parallel kinematic machine architectures have been proposed, but few have actually been used in production environments. The class of machine structures referred to as hybrid parallel kinematic machines have been more successful than most and have been employed in a wide variety of applications. These machines are however still affected by many of the limitations associated with purely parallel structures. One of these is temperature-related error due to thermal expansion of the parallel machine links. This paper proposes and demonstrates a method of compensating for this error. The paper presents details of the method, developed, the development of the required kinematic model and its test and validation using a real production machine, the NEOS Tricept.