Stability Analysis of Dual-rate Haptics Controller Using Two Control Architectures

Abstract

Digital implementation of uniform-rate haptics controller limits the range of virtual environment parameters that can be stably implemented, particularly at higher sampling rates. Dual-rate sampling scheme alleviates this limitation and enlarges the range of these parameters that can be stably implemented. In this paper, theoretical stability analysis of the dual-rate haptics controller is presented using two control architectures. Analytical conditions that guarantee the closed-loop stability of the system are developed using linear control theory tools. The stability criteria constrains the virtual environment parameters as a function of the ratio of sampling periods of the controller, and thereby establish limits on the performance of these controllers. The developed criteria can be seen as the generalization of existing criterion available in the literature.