An EMG enhanced impedance and force control framework for telerobot operation in space

Tele-operation is a merging point of modern developments in robotics and communications technologies. Both traditional applications (e.g., mining) and emerging domains (e.g., microsurgery) benefit from the advancement of tele-robotic systems. Combining a local human operator and a remote autonomous robot, the tele-robotics systems could optimally exploit both the intelligence of human operator and the automation of robot. In a tele-operation scenario, the exchange of force and position signals, i.e., haptic feedback, can greatly extend human operator´s capability of conducting complicated work through the robot in a remote environment. However, long-range communications usually suffer from the time delay problem caused by the inherent characteristics of communication channels. Delayed transmission of haptic signals may lead to instability in the closed-loop telerobot control system. Although much effort has been made in the control community to overcome this difficulty, and many approaches such as wave scattering, passivity, and small gain theorem have been employed as possible solutions, stability in haptic telerobot control remains a challenge. It has been noted that the neural path of human being is also subject to transmission delay as well. We know that in the presence of time delay in sensory feedback pathways, human neural control can easily maintain stability and even to show superior manipulation skills in unstable interaction scenarios. It has been discovered and reported that the operation stability of human beings could be achieved by well adjusting the mechanical impedance, i.e., the resistance to imposed motion, which is largely contributed by the spring-like property of muscles.