Title :
Enlarging regions of stable running with segmented legs
Author :
Rummel, Juergen ; Iida, Fumiya ; Smith, James Andrew ; Seyfarth, Andre
Author_Institution :
Locomotion Lab., Univ. of Jena, Jena
Abstract :
In human and animal running spring-like leg behavior is found, and similar concepts have been demonstrated by various robotic systems in the past. In general, a spring-mass model provides self-stabilizing characteristics against external perturbations originated in leg-ground interactions and motor control. Although most of these systems made use of linear spring-like legs. The question addressed in this paper is the influence of leg segmentation (i.e. the use of rotational joint and two limb-segments) to the self-stability of running, as it appears to be a common design principle in nature. This paper shows that, with the leg segmentation, the system is able to perform self-stable running behavior in significantly broader ranges of running speed and control parameters (e.g. control of angle of attack at touchdown, and adjustment of spring stiffness) by exploiting a nonlinear relationship between leg force and leg compression. The concept is investigated by using a two- segment leg model and a robotic platform, which demonstrate the plausibility in the real world.
Keywords :
legged locomotion; stability; external perturbations; leg-ground interactions; linear spring-like legs; motor control; robotic systems; segmented legs; self-stable running behavior; spring-like leg behavior; Control systems; Force control; Laboratories; Leg; Legged locomotion; Nonlinear control systems; Robotics and automation; Solid modeling; Springs; USA Councils;
Conference_Titel :
Robotics and Automation, 2008. ICRA 2008. IEEE International Conference on
Conference_Location :
Pasadena, CA
Print_ISBN :
978-1-4244-1646-2
Electronic_ISBN :
1050-4729
DOI :
10.1109/ROBOT.2008.4543235