Review on Force-Sensor-Less Power Assist Control

This Paper describes the generalised structure of Force-Sensor-less Power assist control (FSPAC) which is an essential technology to design a feedback control system in a human friendly way. Paper clarifies regarding generalised structure of Force-Sensor-less power assist control using two force observer. The Force, which is used to assist the control system is estimated by using encoders instead of using force-sensors. This Paper also compares other FSPAC’s with the FSPAC using two observer methodology. Since, this Feedback control system uses positive feedback , the Force-sensor-less Power Assist control deals with weak robustness problem. To increase Robustness of the system , Control design based on disturbance observer with variable gain is also discussed in this paper. Finally paper concludes considering its advantages disadvantages and applications. Keywords—Force Estimation, inner observer , Structure of FSPAC, two observer , variable gain .