Angular observation of joints of geckos moving on horizontal and vertical surfaces

Abstract

Because of their outstanding climbing and motor coordination ability, geckos have provided the basis for a peculiar bionic model leading to the development of a gecko-robot. A three-dimensional locomotion observation system was constructed to measure angular orientations of joints while geckos trotted (337.1 mm/s) and walked (66.7 mm/s) on horizontal surfaces, and trotted (241.5mm/s) and walked (30.6mm/s) on vertical surfaces. Moving over horizontal surfaces, the joints rotated more quickly the greater the speed, and the swinging scope of forelimbs stayed nearly at 59 degrees when swinging forward, but extended from 72 degrees to 79.2 degrees when swinging backward. The lifting angle of forelimbs was always positive to keep the center of mass close to the surface when moving up vertical surfaces, the scope of the forward swinging forelimbs forward extended from 33.7 degrees to 36.7 degrees with increasing speed, while the scope of backward swinging forelimbs remained almost the same at 87.5 degrees. Alternative gaits had little effect on the swing angle of hindlimbs of the geckos moving on both horizontal and vertical surfaces.gecko, motor coordination, 3 dimensional observation, joint rotation Locomotion involves the harmonious activity of the entire animal, depending especially on the coordinated action of muscles, bones, nervous system and sense organs [1] . Spatio-temporal gait characteristics and patterns of locomotive cycles are the collective results of the intrinsic properties and motion system of each animal [2][3][4][5] . Performance studies on animal locomotion refers to the interdisciplinary field of physiology and mechanics, which will not only help us to understand the regularity of animal locomotion, but also offer natural models and academic guidance on mechanical design, gait planning and control systems of bionic robots.Over the long evolutionary periods of species, morphological characteristics of body and limbs have been optimized to improve the species' motion performance, particularly in adapting to special environmental circumstances. Morphological adaptations that permit scansorial habits are obvious, for example, adhesive pads, sculptured skin and flattened body shape of geckos, the claws of cats, and the suction cups of tree frogs.The habitats of terrestrial tetrapods are usually rugged, consisting of ravines, inclines and cliffs. Animals must generate sufficient propulsive forces to move over steep or vertical substrata, not only to overcome inertia and environmental resistances from substrata and air, but also to counter gravity [6,7] . On inclines, forelimbs must pull on the substratum to avoid tumbling backwards while hindlimbs push to provide propulsion [6] , and the center of mass close to the substratum is presumably

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Development of agricultural bionic mechanisms: investigation of the effect of joint angle and pressure on the stability of goats moving on sloping lands

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A Biomimetic Study of Discontinuous-Constraint Metamorphic Mechanism for Gecko-Like Robot

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