A robust single device MOSFET series resistance extraction method considering horizontal-field-dependent mobility

A simple MOSFET series resistance extraction method using multiple drain current vs. gate voltage curves of a single device is proposed, where mobility modulation by horizontal electric field (i.e., weak velocity saturation) is taken into account. The method is validated using TCAD, where series resistance determined from internal potential distributions was used as reliable reference. Measurement results were also obtained which further support the validity of the method.

Impedance Control Considering Velocity Saturation of a Series Elasticity System with a Motor

Human-machine cooperative robots are required to drive their arms with low impedance and high torque. As a compact mechanism that generates a large torque and has low impedance characteristics, the series elastic drive system, in which an elastic element is inserted between the motor and driving unit, has been proposed. In this paper, we propose a method of applying impedance control to a series elasticity system with a torque-compensating motor that uses a torsion bar as an elastic body that enables its use under high loads. The stability of the system was verified via simulation and experiment by considering the allowable speed and maximum torque of the motor. The experimental results from the conventional system and the proposed system were compared. The proposed system was confirmed to be superior to the conventional system in terms of both stability and tracking performance. Consequently, the effectiveness of our proposed system was confirmed.