Abstract
In this paper, we aim at achieving accurate positioningcontrol of a pneumatic artificial antagonist-type actuation mechanism. This system has favorable characteristics such as safe interaction with humans and high flexibility. However, due to the nonlinearity of the system behavior as well as the weak rigidity of the compressed air, it is quite difficult to achieve accurate positioning control. To overcome these difficulties, in our preceding studies, we adopted the design method of two-degree-of-freedom (2DOF) LQI servo systems, by which satisfactory tracking performance for step references was achieved under various load conditions.In this paper, we consider ramp references and apply the design method of plant-variable (PV) optimal control, which could be regarded as a natural extension of the design method of 2DOF-LQI servo systems. It is demonstrated that accurate and quick tracking can be achieved for step and ramp references by this method.
