Factors affecting trust in the transparency index for stable and intuitive physical human–robot cooperation

Safety, stability, and intuitive control are the three most basic requirements for the design of a physical human–robot cooperation (HRC) system. High transparency is one of the main design objectives for dynamically coupled HRC systems. However, determinants of system transparency and its influence on system performance are unachievable with the current methods available. This paper presents an overview of admittance control as a method of physical interaction control between robots and human operators, in particular on the analysis of the influencing factors to the computational transparency index. The influence of frequency, sampling point number, and cutoff frequency of the weighting function on the transparency of the admittance controller were analyzed and experimentally verified. The controller was implemented on a four degree-of-freedom interactive manipulator to verify system transparency and stability. The experimental results validate the proposed framework.