Tsetserukou, Dzmitry, Hiroyuki Kajimoto, Naoki Kawakami, and Susumu Tachi. 2008. “Safe Reaction of a Robot Arm With Torque Sensing Ability on the External Disturbance and Impact: Implementation of a New Variable Impendance Control ”. Journal of Automation, Mobile Robotics and Intelligent Systems 2 (4): 31-37. https://www.jamris.org/index.php/JAMRIS/article/view/616.