Taking inspiration from local leg feedback control loops present in animal legs, a force threshold-based position (FTP) controller is presented to aid with legged locomotion over irregular terrain. The algorithm uses pre-planned position trajectories and force feedback to either elevate or depress the foot. The FTP controller isolates the control of each leg to use only localized feedback, which can result in greater responsiveness to the terrain when compared to a centralized controller arbitrating all of the joint positions in a high degree of freedom system. The controller is robust to terrain elevations without using visual sensors, a priori terrain information, inertial sensing or inter-leg communication. Results of the FTP controller applied to a hexapod system in simulation and on an experimental system are shown in this paper. The algorithm also has the potential for expansion to bipeds, quadrupeds and other biologically-inspired forms.
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Allen, T., Quinn, R., Bachmann, R., & Ritzmann, R. (2003). Abstracted biological principles applied with reduced actuation improve mobility of legged vehicles. In Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems (pp. 1370–1375).
Altendorfer, R., Moore, N., Komsuoglu, H., Buehler, M., Brown, J. H. B., McMordie, D., et al. (2001). Rhex: A biologically inspired hexapod runner. Autonomous Robots, 11, 207–213.
Anonymous (1967). Logistical vehicle off-road mobility. Technical Report, U.S. Army Transportation Combat Developments Agency, Fort Eustis, VA.
Bender, J., Simpson, E., Tietz, B., Daltorio, K., Quinn, R., & Ritzmann, R. (2011). Kinematic and behavioral evidence for a distinction between trotting and ambling gaits in the cockroach blaberus discoidalis. Journal of Experimental Biology, 214, 2057–2064.
Boston Dynamics. (2012). LS3 Legged Squad Support System. Retrieved February 02, 2013 from http://www.bostondynamics.com/robot_ls3.html.
Cruse, H. (1976). The function of the legs in the free walking stick insect, Carausius morosus. Journal of Comparative Physiology A: Neuroethology, Sensory, Neural, and Behavioral Physiology, 112(2), 235–262.
Cruse, H. (1985). Which parameters control the leg movement of a walking insect? I. Velocity control during the stance phase. Journal of Experimental Biology, 116(1), 343–355.
Cruse, H., Kindermann, T., Schumm, M., Dean, J., & Schmitz, J. (1998). Walknet: A biologically inspired network to control six-legged walking. Neural Networks, 11(78), 1435–1447.
Ekeberg, O., Blumel, M., & Buschges, A. (2004). Dynamic simulation of insect walking. Arthropod Structure and Development, 33(3), 287–300.
Ferrell, C. (1994). Robust and adaptive locomotion of an autonomous hexapod. In Proceedings of the From Perception to Action Conference (pp. 66–77).
Full, R. J. (1989). Mechanics and energetics of terrestrial locomotion: From bipeds to polypeds. Energy Transformation in Cells and Animals (pp. 175–182). Berlin: Georg Thieme Verlag.
Full, R. J., & Koditschek, D. E. (1999). Templates and anchors: Neuromechanical hypotheses of legged locomotion on land. Journal of Experimental Biology, 202, 3325–3332.
Full, R. J., & Tu, M. (1990). The mechanics of six-legged runners. Journal of Experimental Biology, 148, 129–146.
Full, R. J., Blickhan, R., & Tu, M. (1991). Leg design in hexapedal runners. Journal of Experimental Biology, 158, 369–390.
Goldman, D. I., Chen, T. S., Dudek, D. M., & Full, R. J. (2006). Dynamics of rapid vertical climbing in cockroaches reveals a template. Journal of Experimental Biology, 209, 2990–3000.
Goldschmidt, D., Hesse, F., Wörgötter, F., & Manoonpong, P. (2012). Biologically inspired reactive climbing behavior of hexapod robots. In IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2012 (pp. 4632–4637).
Hirose, S. (1984). A study of design and control of a quadruped walking vehicle. The International Journal of Robotics Research, 3(2), 113–133.
Hutter, M., Gehring, C., Bloesch, M., Hoepflinger, M., Remy, C., & Siegwart, R. (2012). StarlETH: A compliant quadrupedal robot for fast, efficient, and versatile locomotion. In 15th International Conference on Climbing and Walking Robot - CLAWAR 2012.
Kalakrishnan, M., Buchli, J., Pastor, P., Mistry, M., & Schaal, S. (2010). Learning, planning, and control for quadruped locomotion over challenging terrain. International Journal of Robotics Research, 30, 236–258.
Kaliyamoorthy, S., Zill, S. N., Quinn, R. D., Ritzmann, R. E., Choi, J. (2001). Finite element analysis of strains in a blaberus cockroach leg during climbing. In IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2011 (pp. 833–838).
Kawato, M., Furukawa, K., & Suzuki, R. (1987). A hierarchical neural-network model for control and learning of voluntary movement. Biological Cybernetics, 57, 169–185.
Kolter, J., & Ng, A. Y. (2011). The stanford littledog: A learning and rapid replanning approach to quadruped locomotion. The International Journal of Robotics Research, 30(2), 150–174.
Kovac, M., Fuchs, M., Guignard, A., Zufferey, J.-C., & Floreano, D. (2008). A miniature 7g jumping robot. In Proceedings of the IEEE International Conference on Robotics and Automation (pp. 373–378).
Kubow, T. M., & Full, R. J. (1999). The role of the mechanical system in control: A hypothesis of selfstabilization in hexapedal runners. Philosophical Transactions of the Royal Society of London Series B: Biological Sciences, 354(1385), 849–861.
Lee, W., & Orin, D. (1988). The kinematics of motion planning for multilegged vehicles over uneven terrain. IEEE Journal of Robotics and Automation, 4(2), 204–212.
Lewinger, W., Rutter, B., Blümel, M., Büschges, A., & Quinn, R. (2006). Sensory coupled action switching modules (SCASM) generate robust, adaptive stepping in legged robots. In Proceedings of CLAWAR 2006, 9th International Conference on Climbing and Walking Robots.
Lewinger, W. A., & Quinn, R. D. (2011). Neurobiologically-based control system for an adaptively walking hexapod. Industrial Robot: An International Journal, 38(3), 258–263.
Liang, X., Xu, M., Xu, L., Liu, P., Ren, X., Kong, Z., Yang, J., Zhang, S. (2012). The amphihex: A novel amphibious robot with transformable leg-flipper composite propulsion mechanism. In IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), 2012 (pp. 3667–3672).
McMillan, S., Orin, D. E., & McGhee, R. B. (1995). DynaMechs: An object oriented software package for efficient dynamic simulation of underwater robotic vehicles. In J. Yuh (Ed.), Underwater Robotic Vehicles: Design and Control (pp. 73–98). Albuquerque, NM: TSI Press.
Moore, E., Campbell, D., Grimminger, F., Buehler, M. (2002). Reliable stair climbing in the simple hexapod ’rhex’. In IEEE International Conference on Robotics and Automation, 2002. Proceedings. ICRA ’02 (pp. 2222–2227).
Murphy, M. P., Saunders, A., Moreira, C., Rizzi, A. A., & Raibert, M. (2011). The littledog robot. The International Journal of Robotics Research, 30(2), 145–149.
Neville, N., Buehler, M., & Sharf, I. (2006). A bipedal running robot with one actuator per leg. In Proceedings of the IEEE International Conference on Robotics and Automation (pp. 848–853).
Orin, D. E. (1982). Supervisory control of a multilegged robot. International Journal of Robotics Research, 1(4), 79–91.
Palmer III, L. R., & Eaton, C. (2012). Toward innate leg stability on unmodeled and natural terrain: Quadruped walking. In Proceedings of the IEEE/RSJ International Conference on Intelligent Robots and Systems.
Pongas, D., Mistry, M., Schaal, S. (2007). A robust quadruped walking gait for traversing rough terrain. In IEEE International Conference on Robotics and Automation (pp. 1474–1479).
Prochazka, A., Gillard, D., & Bennett, D. J. (1997). Implications of positive feedback in the control of movement. Journal of Neurophysiology, 77, 3237–3251.
Raibert, M., Blankespoor, K., Nelson, G., & Playter, R., et al. (2008). Bigdog, the rough-terrain quadruped robot. In Proceedings of the 17th World Congress (pp. 10,823–10,825).
Rebula, J., Neuhaus, P., Bonnlander, B., Johnson, M., & Pratt, J. (2007). A controller for the littledog quadruped walking on rough terrain. In IEEE International Conference on Robotics and Automation (pp. 1474–1479).
Saranli, U., Buehler, M., & Koditschek, D. (2000). Design, modeling and preliminary control of a compliant hexapod robot. In Proceedings of the IEEE International Conference on Robotics and Automation (pp. 2589–2596).
Saranli, U., Buehler, M., & Koditschek, D. E. (2001). Rhex: A simple and highly mobile hexapod robot. The International Journal of Robotics Research, 20(7), 616–631.
Schroer, R., Boggess, M., Bachmann, R., Quinn, R., Ritzmann, R. (2004). Comparing cockroach and whegs robot body motions. In IEEE International Conference on Robotics and Automation, 2004. Proceedings. ICRA ’04. 2004 (pp. 3288–3293).
Song, S. M., & Waldron, K. J. (1989). Machines that Walk. Cambridge, MA: MIT Press.
Sponberg, S., Spence, A., Mullens, C., & Full, R. (2011). A single muscle’s multifunctional control potential of body dynamics for postural control and running. Philosophical Transactions of the Royal Society B: Biological Sciences, 366, 1592–1605.
Ting, L. H., Blickhan, R., & Full, R. J. (1994). Dynamic and static stability in hexapedal runners. Journal of Experimental Biology, 197(1), 251–269.
Vernaza, P., Likhachev, M., Bhattacharya, S., Chitta, S., Kushleyev, A., & Lee, D. (2009). Search-based planning for a legged robot over rough terrain. In IEEE International Conference on Robotics and Automation, 2009. ICRA ’09 (pp. 2380–2387).
Whelan, P. (1996). Control of locomotion in the decerebrate cat. Progress in Neurobiology, 49, 481–515.
Zill, S., Keller, B., Chaudhry, S., Duke, E., Neff, D., Quinn, R., et al. (2010). Detecting substrate engagement: responses of tarsal campaniform sensilla in cockroaches. Journal of Comparative Physiology A, 196, 407–420.
The authors would like to thank Nellie Bonilla and Miguel Veliz for their help with the experimental hardware and Jeffrey Price for his work with the RobotBuilder simulation environment. This work is supported by the DARPA Maximum Mobility and Manipulation (M3) Program.
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Palankar, M., Palmer, L. A force threshold-based position controller for legged locomotion. Auton Robot 38, 301–316 (2015) doi:10.1007/s10514-014-9413-0