Estimation of Friction-torque to Improve Accuracy of Estimated Contact-force for a Walking Robot

접촉력 추정 정확도 향상을 위한 보행로봇의 마찰 토크 추정

Lee, Jonghwa;Kang, Hangoo;Lee, Jihong;Jun, Bong-Huan

  • Received : 2015.07.28
  • Accepted : 2015.10.28
  • Published : 2015.10.31


This paper introduces a method to estimate the contact-force of the leg of a walking robot and proposes a solution to a shortcoming of the previous study. This shortcoming was the deteriorating performance when estimating the contact-force whenever the rotation of each joint was reversed. It occurred because the friction-torque of each joint was not considered. In order to solve this problem, a friction-torque model for a robot leg was developed based on repetitive experimentation and used to improve the contact-force estimation performance. We verified the performance of the proposed method experimentally.


Force estimation;Friction-torque;Walking robot;CRABSTER;Manipulator


  1. Lee, J.H., Jeon, S.G., Lee, J.H., 2014. 3-dimensional Force Estimation for a Robot Leg with Single-axial Force and Motor Current. Proceedings of Institute of Control Robotics and Systems, Daejeon, Korea, 153-155.
  2. Park, J.H., 2001. Impedance Control for Biped Robot Locomotion. Robotics and Automation. IEEE Transactions on, 17(6), 870-882.
  3. Phong, L.D., Choi, J.H., Kang, S.C., 2012. External Force Estimation using Joint Torque Sensors for a Robot Manipulator. Proceedings of the IEEE International Conference on Robotics and Automation, Minnesota USA, 4507-4512.
  4. Stolt, A., Linderoth, M., Robersson, A., Johansson, R., 2012. Force Controlled Robotic Assembly without a Force Sensor. Proceedings of the IEEE International Conference on Robotics and Automation, Minnesota USA, 1538-1543.
  5. Walas, K., 2013a. Tactile Sensing for Ground Classification. Journal of Automation Mobile Robotics and Intelligent Systems, 7(2), 18-23.
  6. Walas, K., 2013b. Hardware Implementation of Ground Classification for a Walking Robot. Proceedings of 9th International Workshop on Robot Motion and Control, Wasowo Poland, 110-115.
  7. Walas, K., 2015. Terrain Classification and Negotiation with a Walking Robot. Journal of Intelligent and Robotic Systems, 78(3-4), 401-423.
  8. Yi, S., 2013. Stable Walking of Qauadruped Robot by Impedance Control for Body Motion. International Journal of Control and Automation, 6(2), 99-110.
  9. Aksman, L.M., Carignan, C.R., Akin, D.L., 2007. Force Estimation Based Compliance Control of Harmonically Driven Manipulators. Proceedings of the IEEE international conference on robotics and Automation, Roma Italy, 4208-4213.
  10. Arevalo, J.C., Garcia, E., 2012. Impedance Control for Legged Robots: An Insight into the Concepts Involved. Systems, Man, and Cybernetics, Part C: Applications and Reviews, IEEE Transactions on, 42(6), 1400-1411.
  11. Helmick, D., Okon, A., DiCicco, M., 2006. A Comparison of Force Sensing Techniques for Planetary Manipulation. Proceedings of the IEEE Aerospace Conference.
  12. Hoepflinger, M.A., Remy, C.D., Hutter, M., Spinello, L., Siegwart, R., 2010. Haptic Terrain Classifiaction for Legged Robots. Proceedings of IEEE International Conference Robotics and Automation, Anchorage AK, 2828-2833.