An eigenscrew analysis of mechanism compliance

Determination of the magnitudes and directions of the constraints of a mechanical system can be achieved by finding the basis of the system´s characteristics compliance matrix. When little is known about the geometry of the system, conventional methods cannot be used to calculate the system´s compliance matrix. A new method has been developed that uses experimental data to calculate a passive system´s compliance matrix,and an eigenvalue decomposition to extract the directions and magnitudes of the system constraints. The data were wrenches applied to the system and the mechanism´s resulting displacement from equilibrium. Computer simulations suggest that the method reliably finds eigenscrew pitches, compliances and directions for well-conditioned matrices. Eigenscrew pitches and compliances can be found for ill-conditioned matrices. This analytical technique can be used to evaluate the static behaviour of a system. It may prove valuable as a design and analysis tool for biomechanics, robotics and automation