Abstract
Locomoting in the surf-zone is a challenge for traditional robots, as they must be able to resist hydrodynamic forces of waves while overcoming the challenges of walking on sand, a granular media. Taking inspiration from live crabs that can navigate the surf zone efficiently, we demonstrate that inward gripping with crab-inspired curved dactyls on a crab-like robot can increase its effective weight underwater, which is the weight of the robot minus the buoyancy force, to better resist wave forces. Gripping can also reduce the cost of transport and allow for more efficient operation in a lab-created surf-zone environment. Six different walking gaits are tested on an 18 degree-of-freedom crab-inspired hexapod robot. The tests are conducted on sand underwater, with and without the presence of waves. Results show that the gait with a smooth swing path combined with front only gripping is on average 50% more energy efficient than the gait with a polygonal swing path with front and rear gripping in still water and 29% more energy efficient in waves.
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References
Blickhan, R., Full, R.J.: Locomotion energetics of the ghost crab: II. Mechanics of the centre of mass during walking and running. J. Exp. Biol. 130(1), 155–174 (1987). https://doi.org/10.1242/jeb.130.1.155
Chen, X., Li, J., Hu, S., Han, S., Liu, K., Pan, B., Wang, J., Wang, G., Ma, X.: Study on the design and experimental research on a bionic crab robot with amphibious multi-modal movement. J. Mar. Sci. Eng. 10(12), 1804 (2022). https://doi.org/10.3390/jmse10121804
Chen, Y., et al.: Optimal planar leg geometry in robots and crabs for idealized rocky terrain. Bioinspiration Biomimetics 17(6), 066009 (2022)
Chen, Y., Grezmak, J.E., Graf, N.M., Daltorio, K.A.: Sideways crab-walking is faster and more efficient than forward walking for a hexapod robot. Bioinspiration Biomimetics 17(4), 046001 (2022)
Gong, Y., Behr, A.M., Graf, N.M., Chen, K., Gong, Z., Daltorio, K.A.: A walking claw for tethered object retrieval. J. Mech. Robot. 15(5), 051014 (2022). https://doi.org/10.1115/1.4055812
Graf, N.M., Behr, A.M., Daltorio, K.A.: Dactyls and inward gripping stance for amphibious crab-like robots on sand. Bioinspiration Biomimetics 16(2), 026021 (2021)
Graf, N.M., Grezmak, J.E., Daltorio, K.A.: Get a grip: inward dactyl motions improve efficiency of sideways-walking gait for an amphibious crab-like robot. Bioinspiration Biomimetics 17(6), 066008 (2022)
Herreid, C.F., Full, R.J.: Locomotion of hermit crabs (Coenobita Compressus) on beach and treadmill. J. Exp. Biol. 120(1), 283–296 (1986). https://doi.org/10.1242/jeb.120.1.283
Martinez, M.M.: Running in the surf: hydrodynamics of the shore crab Grapsus tenuicrustatus. J. Exp. Biol. 204(17), 3097–3112 (2001). https://doi.org/10.1242/jeb.204.17.3097
Schmiedeler, J.P., Bradley, N.J., Kennedy, B.: Maximizing walking step length for a near omni-directional hexapod robot. In: International Design Engineering Technical Conferences and Computers and Information in Engineering Conference, vol. Volume 2: 28th Biennial Mechanisms and Robotics Conference, Parts A and B, pp. 1371–1380 (2004). https://doi.org/10.1115/DETC2004-57531
Seethapathi, N., Srinivasan, M.: The metabolic cost of changing walking speeds is significant, implies lower optimal speeds for shorter distances, and increases daily energy estimates. Biol. Lett. 11(9), 20150486 (2015)
Taylor, J.R.A.: Aquatic versus terrestrial crab skeletal support: morphology, mechanics, molting and scaling. J. Exp. Biol. 221(21), jeb185421 (2018)
Yang, K., Li, Y., Zhou, L., Rong, X.: Energy efficient foot trajectory of trot motion for hydraulic quadruped robot. Energies 12(13), 2514 (2019)
Zhang, J., Liu, Q., Zhou, J., Song, A.: Crab-inspired compliant leg design method for adaptive locomotion of a multi-legged robot. Bioinspiration Biomimetics 17(2), 025001 (2022)
Zhu, Y., Abdulmajeid, L., Hauser, K.: A data-driven approach for fast simulation of robot locomotion on granular media. In: 2019 International Conference on Robotics and Automation (ICRA), pp. 7653–7659 (2019)
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Silberstein, Z., Pan, M., Carmichael, N., Daltorio, K.A. (2025). Moving Inward with Front Legs Improves Tripod Gaits for Crab-Like Robot Walking in Sand. In: Szczecinski, N.S., Webster-Wood, V., Tresch, M., Nourse, W.R.P., Mura, A., Quinn, R.D. (eds) Biomimetic and Biohybrid Systems. Living Machines 2024. Lecture Notes in Computer Science(), vol 14930. Springer, Cham. https://doi.org/10.1007/978-3-031-72597-5_21
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