Volume 24 Issue 7 - Publication Date: 1 July 2005
Special Issue on the 6th International Conference on Climbing and Walking Robots (CLAWAR 2003)
A Parametric Optimization Approach toWalking Pattern Synthesis
G. Bessonnet, P. Seguin, and P. Sardain Laboratoire de Mécanique des Solides, CNRS-UMR6610, Université de Poitiers, SP2MI, Bd. M. & P. Curie, BP 30179, 86962 Futuroscope Chasseneuil cedex, France
Walking pattern synthesis is carried out using a spline-based parametric optimization technique. Generalized coordinates are approximated by spline functions of class C3 fitted at knots uniformly distributed along the motion time. This high-order differentiability eliminates jerky variations of actuating torques. Through connecting conditions, spline polynomial coefficients are determined as a linear function of the joint coordinates at knots. These values are then dealt with as optimization parameters. An optimal control problem is formulated on the basis of a performance criterion to be minimized, representing an integral quadratic amount of driving torques. Using the above spline approximations, this primary problem is recast into a constrained non-linear optimization problem of mathematical programming, which is solved using a computing code implementing an SQP algorithm. As numerical simulations, complete gait cycles are generated for a seven-link planar biped. The only kinematic data to be accounted for are the walking speeds. Optimization of both phases of gait is carried out globally; it includes the optimization of transition configurations of the biped between successive phases of the gait cycle.
Multimedia Key
= Video = Data = Code = Image
Example One: File: Walk_Speed_070.mpg CAD view of the biped walking at 0.70m/s. (1.2 MB)
Example Two: File: Walk_Speed_130.mpg CAD view of the biped walking at 1.30m/s. (0.8 MB)

Example Three: File: Walk_Speed_045.mpg CAD view of the biped walking at 0.45m/s. (1.7 MB)

Example Four: File: Walk_Speed_100.mpg CAD view of the biped walking at 1.00m/s. (0.9 MB)
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