Abstract
We develop a simple hexapedal model for the dynamics of insect locomotion in the horizontal plane. Each leg is a linear spring endowed with two inputs, controlling force-free length and “hip” position, in a stereotypical feedforward pattern. These represent, in a simplified manner, the effects of neurally activated muscles in the animal and are determined from measured foot force and kinematic body data for cockroaches. We solve the three-degree-of-freedom Newtonian equations for coupled translation-yawing motions in response to the inputs and determine branches of periodic gaits over the animal’s typical speed range. We demonstrate a close quantitative match to experiments and find both stable and unstable motions, depending upon input protocols.Our hexapedal model highlights the importance of stability in evaluating effective locomotor performance and in particular suggests that sprawled-posture runners with large lateral and opposing leg forces can be stable in the horizontal plane over a range of speeds, with minimalsensory feedback from the environment. Fore–aft force patterns characteristic of upright-posture runners can cause instability in the model. We find that stability can constrain fundamental gait parameters: our model is stable only when stride length and frequency match the patterns measured in the animal. Stability is not compromised by large joint moments during running because ground reaction forces tend to align along the leg and be directed toward the center of mass. Legs radiating in all directions and capable of generating large moments may allow very rapid turning and extraordinary maneuvers. Our results further weaken the hypothesis that polypedal, sprawled-posture locomotion with large lateral and opposing leg forces is less effective than upright posture running with fewer legs.
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References
Alexander NMcR (1989) Optimisation and gaits in the locomotion of vertebrates. Physiol Rev 69:1199–1227
Alexander NMcR, Jayes AS (1983) A dynamic similarity hypothesis for the gaits of quadrupedal maammals. J Zool Lond 201:135–152
Biewener AA (2003) Animal locomotion. Oxford University, Oxford
Biewener AA, Taylor CR (1986) Bone strain: a determinant of gait and speed? J Exp Biol 123:383–400
Blickhan R (1989) The spring-mass model for running and hopping. J Biomech 11/12:1217–1227
Blickhan R, Full RJ (1993) Similarity in multi-legged locomotion: bouncing like a monopode. J Comp Physiol A 173:509–517
Brown IE, Loeb GE (2000) A reductionist approach to creating and using neuromusculoskeletalmovement. In: Winters MJ, Crago EP (eds) Biomechanics and neural control of movement. Springer, Berlin Heidelberg New York, pp 148–163
Brown IE, Scott SH, Loeb GE (1995) ‘‘Preflexes’’ – programmable high-gain zero-delay intrinsic responses of perturbed musculoskeletal systems. Soc Neurosci Abstr 21:562.9
Cavagna GA, Heglund NC, Taylor CR (1977) Mechanical work in terrestrial locomotion: two basic mechanisms for minimizing energy expenditure. Am J Physiol 233(5):R243–R261
Chong L, Culotta E, Sugden A (eds) (2000) On the move: Movement: molecular to robotic. Science 288:79–106
Collins JJ, Stewart I (1993) Hexapodal gaits and coupled nonlinear oscillator models. Biol Cybern 68(4):287–298
Dickinson MH, Farley CT, Full RJ, Koehl MAR, Kram R, Lehman S (2000) How animals move: an integrative view. Science 288:100–106
Farley CT, Taylor CR (1991) A mechanical trigger for the trot-gallop transition in horses. Science 253:306–308
Full RJ (1989) Mechanics and energetics of terrestrial locomotion: from bipeds to polypeds. In: Weiser W, Gnaiger E (eds) Energy transformation in cells and animals. Georg Thieme, Stuttgart, pp 175–182
Full RJ (1993) Integration of individual leg dynamics with whole body movement in arthropod locomotion. In: Beer R, Ritzmann R, McKenna T (eds) Biological neural networks in invertebrate neuroethology and robots. Academic, Boston, pp 3–20
Full RJ, Ahn AN (1995) Static forces and moments generated in the insect leg: comparison of a three-dimensional musculo-skeletal computer model with experimental measurements. J Exp Biol 198:1285–1298
Full RJ, Koditschek DE (1999) Templates and anchors: neuromechanical hypotheses of legged locomotion on land. J Exp Biol 202:3325–3332
Full RJ, Tu MS (1990) Mechanics of six-legged runners. J Exp Biol 148:129–146
Full RJ, Tu MS (1991) Mechanics of a rapid running insect: two- four- and six-legged locomotion. J Exp Biol 156:215–231
Full RJ, Blickhan R, Ting LH (1991) Leg design in hexpedal runners. J Exp Biol 158:369–390
Full RJ, Stokes D, Ahn AN, Josephson RK (1998) Energy absorption during running by leg muscles in a cockroach. J Exp Biol 201:997–1012
Full RJ, Kubow T, Schmitt J, Holmes P, Koditschek D (2002) Quantifying dynamic stability and maneuverability in legged locomotion. Integ Comp Biol 42:149–157
Golubitsky M, Stewart I, Buono PL, Collins JJ (1999) Symmetry in locmotor central pattern generators and animal gaits. Nature 401:693–695
Guckenheimer J, Holmes P (1990) Nonlinear oscillations dynamical systems and bifurcations of vector fields. Springer, Berlin Heidelberg New York
Guckenheimer J, Johnson S (1995) Planar hybrid systems. Lecture notes in computer science, vol 999. Springer, Berlin Heidelberg New York
Heglund NC, Taylor CR (1988) Speed stride frequency and energy cost per stride. How do they change with body size and gait? J Exp Biol 138:301–318
Herr H, Huang GT, McMahon TA (2002) A model of scale effects in mammalian quadrupedal running. J Exp Biol 205:959–967
Höltje M, Hustert R (2003) Rapid mechano-sensory pathways code leg impact and elicit very rapid reflexes in insects. J Exp Biol 206:2715–2724
Hoyt DF, Taylor CR (1981) Gait and the energetics of locomotion in horses. Nature 292:239–240
Jindrich D, Full RJ (1999) Many-legged maneuverability: dynamics of turning in hexapods. J Exp Biol 202:1603–1623
Jindrich D, Full RJ (2002) Dynamic stabilization of rapid hexapedal locomotion. J Exp Biol 205:2803–2823
Kram R, Wong B, Full RJ (1997) Three-dimensional kinematics and limb kinetic energy of running cockroaches. J Exp Biol 200:1919–1929
Kubow TM, Full RJ (1999) The role of the mechanical system in control: a hypothesis of self-stabilization in hexapedal runners. Philos Trans R Soc Lond B 354:849–861
Lee DV, Bertram JEJ, Todhunter RJ (1999) Acceleration and balance in trotting dogs. J Exp Biol 202:3565–3573
Maddocks J (1984) Stability of nonlinearly elastic rods. Arch Rat Mech Anal 85:311–354
Maddocks J (1987) Stability and folds. Arch Rat Mech Anal 99:301–328
McMahon TA, Cheng GC (1990) The mechanics of running: how does stiffness couple with speed? J Biomech 23(suppl 1):65–78
Powell MJD (1970) A Fortran subroutine for solving systems of nonlinear algebraic equations. In: Rabinowitz P (ed) Numerical methods for nonlinear algebraic equations. Gordon and Breach, London, pp 115–161
Ruina A (1998) Non-holonomic stability aspects of piecewise holonomic systems. Rep Math Phys 42(1/2):91–100
Schmitt J, Holmes P (2000a) Mechanical models for insect locomotion: dynamics and stability in the horizontal plane – theory. Biol Cybern 83(6):501–515
Schmitt J, Holmes P (2000b) Mechanical models for insect locomotion: dynamics and stability in the horizontal plane – application. Biol Cybern 83(6):517–527
Schmitt J, Holmes P (2001) Mechanical models for insect locomotion: stability and parameter studies. Physica D 156(1–2): 139–168
Schmitt J, Holmes P (2003) Mechanical models for insect locomotion: active muscles and energy losses. Biol Cybern 89(1):43–55
Schmitt J, Garcia M, Razo CR, Holmes P, Full RJ (2002) Dynamics and stability of legged locomotion in the horizontal plane: a test case using insects. Biol Cybern 86(5):343–353
Schoner G, Jiang WY, Kelso JA (1990) A synergetic theory of quadrupedal gaits and gait transitions. J Theor Biol 142:359–391
Taylor CR (1978) Why change gaits? Recruitment of muscles and muscle fibers as a function of speed and gait. Am Zool 18:153–161
Taylor CR (1985) Force development during sustained locmotion: a determinant of gait speed and metabolic power. J Exp Biol 115:253–262
Ting LH, Blickhan R, Full RJ (1994) Dynamic and static stability in hexapedal runners. J Exp Biol 197:251–269
Vilensky JA, Libii JN, Morre M (1991) Trot-gallop gait transitions in quadrupeds. Physiol Behav 50:835–842
Waldron KJ (1986) Force and motion management in legged locomotion. IEEE J Robot Automat RA-2(4):214–220
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Seipel, J., Holmes, P. & Full, R. Dynamics and stability of insect locomotion: a hexapedal model for horizontal plane motions. Biol. Cybern. 91, 76–90 (2004). https://doi.org/10.1007/s00422-004-0498-y
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DOI: https://doi.org/10.1007/s00422-004-0498-y