An experimental approach to simultaneous structure/control design using rapid recursive prototype modification

This paper describes an experimental recursive method for simultaneously changing both the mechanical structure and control of a positioning system in order to improve the system´s overall control performance. A method is devised which allows a robotic system to improve its control performance through concurrent repetitive reinforcement of its structure and optimization of its control gains. To expedite the process of modifying a prototype structure, a method for coating the structure with steel-reinforced epoxy is developed. A recursive algorithm, based on a gradient descent method and a parameter estimation theory, is developed to determine both the optimal incremental structure changes and the required control parameter changes. The resultant changes are then immediately implemented by using the epoxy reinforcement coating method as well as by changing the control gains. The entire process consisting of experimental evaluation, data analysis, and structure reinforcement is repeated until the task performance is improved to the desired level