Two-step scaling micro-macro bilateral control using double master slave system

Many studies on bilateral control based on 4ch bilateral controller have been carried out hitherto. Micro-macro bilateral control is an application of this method for micro manipulations. Micro-macro bilateral control enables magnifying and demagnifying the force information using scaling gains. However, in the case of a single system as a conventional method, there is a limit of scaling because of instability. This paper analyzes the stability of conventional method considering scaling gain by using root locus analysis. Furthermore, it proposes a two-step scaling micro-macro bilateral control using double master slave system as a new solution. For the new system, two master slave systems are used and connected to each other. A stable whole system is realized by connecting two stable systems with suitable scaling gain. Thus, the proposed method enables a higher scaling micro-macro bilateral control with multiplication of two scalings. Simulations and experimental results are given to show the validity of the proposed method. Comparison with conventional method is achieved by using stability analysis and experiments.