Abstract:
A characterisation of a complete arm prosthesis is necessary to develop effective control. This is a description of the use of Lagrange methodology to describe the system and to optimise for motion control.
The Lagrange equations of motion are derived from the Newtonian equations of motion. Lagrange analysis describes the system in terms of Kinetic (T) and Potential energies (V). The Kinetic energy (T) is found through a generalised co-ordinate system, where T is a function of the co-ordinates and time derivates. In the non-conservative prosthetic arm, potential energy (V) is found from the generalised forces. These descriptions encompass both electrical and mechanical energies, which are then used to provide the optimum control settings.
This analysis method allows multiple terminal analysis points to be combined, allowing an electrical network with losses, and a mechanical network with losses, combined by a coupling network. Thus the analysis allows for n mechanical and electrical terminals in the network. This network approach lends itself to a complete prosthetic arms system, where terminals in the network can range from individual fingers to shoulder joints.
