Locomotion of Biped Robots on Irregular Surface Based on Pseudo-Impedance Model

의사-임피던스 모델을 이용한 비평탄면에서의 2족보행로봇의 보행

  • Received : 2009.02.03
  • Accepted : 2010.04.10
  • Published : 2010.06.01


This paper proposes a control method based on a pseudo-impedance model to control the motion of biped robots walking on an uneven surface. The pseudo-impedance model simulates the action of the ankle of a foot landing on the ground when a human walks. When the foot is in contact with the ground, the human ankle goes through two different phases. In the first phase, the human exerts little or no effort and applies no torque on the ankle so that the orientation of the foot is effortlessly and passively adjusted with respect to the ground. In the second phase of landing, the ankle generates a significant amount of torque in order to rotate and move the main part of the human body forward and to support the weight of the human; this phase is called the weight acceptance phase. Computer simulations of a 12-DOF biped robot with a 6-DOF environment model were performed to determine the effectiveness of the proposed pseudo-impedance control. The simulation results show that stable locomotion can be achieved on an irregular surface by using the proposed model.


Biped Robot;Pseudo-Impedance Model;Uneven Surface;Locomotion


  1. Takanishi, A., Lim, H., Tsuda, M. and Kato, I., 1990, “Realization of Dynamic Biped Walking Stabilized by Trunk Motion on a Sagittally Uneven Surface,” Proc. of IEEE Int. Workshop on Intelligent Robots and Systems, pp. 323-330.
  2. Yamaguchi, J. and Takanishi, A., 1996, “Multisensor Foot Mechanism with Shock Absorbimg Material for Dynamic Biped Walking Adapting to Unknown Uneven Surface,” Proc. of IEEE/SICE/RSJ Int. Conf. on Multisensor Fusion and Integration for Intelligent Systems, pp. 233-240.
  3. Yamaguchi, J., Kinoshita, N., Takanishi, A. and Kato, I., 1996, “Development of a Dynamic Biped Walking System for Humanoid –Development of a Biped Walking Robot Adapting to the Humans’ Living Floor,” Proc. of IEEE Int. Conf. on Robotics and Automation, pp. 232-239.
  4. Kajita, S. and Tani, K., 1996, “Adaptive Gait Control of a Biped Robot Based on Realtime Sensing of the Ground Profile,” Proc. of IEEE Int. Conf. on Robotics and Automation, pp. 570-577.
  5. Vukobratovic, M., Borovac, B., Surla, D. and Stokic, D., 1990, Biped locomotion – Dynamics, Stability, Control and Application, Springer-Verlag.
  6. Park, J. H. and Chung, H. A., 1999, “Impedance Control and Modulation for Stable Footing in Locomotion of Biped Robot,” Proc. of IEEE/RSJ Int. Conf. on Intelligent Robots and Systems, pp.1786-1791.
  7. Fujimoto, Y., Obata, S. and Kawamura, A., 1998, “Robust Biped Walking with Active Interaction Control between Foot and Ground,” Proc. of IEEE Int. Conf. on Robotics and Automation, pp. 2030-2035.
  8. Wang, G., Huang, Q., Geng, J., Deng, H. and Li, K., 2003, “Cooperation of Dynamic Patterns and Sensory Reflex for Humanoid Walking,” Proc. of IEEE Int. Conf. on Robotics and Automation, pp.2472-2477.
  9. Kim, E. S. and Park, J. H., 2005, “Foot Adjusting Motion on Irregularly Protruded Uneven Surface for Biped Robots,” Proc. of KSME 2005 Fall Annual Meeting, 2657-2652.
  10. Park, J. H. and Kim, E. S., 2009, “Foot and Body Control of Biped Robots to Walk on Irregularly Protruded Uneven Surface,” IEEE Trans. on System, Man, and Cybernetics, Part B: Cybernetics, Vol. 39, No. 1, pp. 289-297.
  11. Park, J. H. and Kim, K. D., 1998, “Biped Robot Walking Using Gravity Compensated Inverted Pendulum Mode and Computed Torque Control,” Proc. of IEEE Int. Conf. on Robotics and Automation, pp. 3528-3533.
  12. Chung, H. A. and Park, J. H., 2000, “Control of Biped Robots Based on Impedance Control and Computed-Torque Control,” Trans. of the KSME (A), Vol. 24, No. 6, pp. 1513-1519.
  13. Park, J. H., 2001, “Impedance Control of Biped Locomotion,” IEEE Trans. on Robotics and Automation, Vol. 17, No. 6, pp. 870-882.

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  1. Reference ZMP Trajectory Generation and Implementation for a Biped Robot via Linear Inverted Dumbbell Model (LIDM) vol.29, pp.4, 2012,