New results in NPID control: tracking, integral control, friction compensation and experimental results

Adjusting the parameters of the mechanical impedance for velocity, impact and force control

“…Ferretti, Magnani and Zavala Río 7 proposed to apply during the impact a feedforward determined empirically combined with the force regulator, in order to avoid contact losses. The switching of parameters was introduced in force control by B. Armstrong et al 8,9 , in a study similar to the present work. The authors switch the gain matrix according to the state of the system.…”

Haptic Perception of Real and Virtual Curvature

“…In addition, it is doubtful that our sensors would achieve the required resolution [3]. Since the prospects for increasing performance with linear feedback are limited, we turned our attention to a class of nonlinear controllers -nonlinear pd controllers [4] which are known to be able to deal with dry friction while preserving a smooth response. These controllers come in many types.…”

Robust Tracking Controller Design With Uncertain Friction Compensation Based on a Local Modeling Approach

“…However, the use of a fixed gain may lead to control input saturation and even the generation of limit cycles. To overcome this, a nonlinear gain-scheduling strategy can be introduced [21]. Fig.…”