[1]the College of Automation Engineering Nanjing University of Aeronautics and Astronautics Nanjing 210016 China;
[2]the School of Automation Southeast University Key Laboratory of Measurement and Control of School of Computer Science and Engineering (CSE) Ministry of Education Nanjing 210096 China;
[3]the Department of Aeronautical and Automotive Engineering Loughborough University Loughborough LE11 3TU UK;
Bilateral control; disturbance observer; force haptic; teleoperation;