Controlling legs for locomotion—insights from robotics and neurobiology

Abstract

Walking is the most common terrestrial form of locomotion in animals. Its great versatility and flexibility has led to many attempts at building walking machines with similar capabilities. The control of walking is an active research area both in neurobiology and robotics, with a large and growing body of work. This paper gives an overview of the current knowledge on the control of legged locomotion in animals and machines and attempts to give walking control researchers from biology and robotics an overview of the current knowledge in both fields. We try to summarize the knowledge on the neurobiological basis of walking control in animals, emphasizing common principles seen in different species. In a section on walking robots, we review common approaches to walking controller design with a slight emphasis on biped walking control. We show where parallels between robotic and neurobiological walking controllers exist and how robotics and biology may benefit from each other. Finally, we discuss where research in the two fields diverges and suggest ways to bridge these gaps.

Leg force interference in polypedal locomotion

“…Sufficiently high deviations from θ = 0.5 completely prevent airborne intervals, even though duty factors are considerably lower than 0.5. Consequently, such gaits facilitate permanent proprioceptive feedback and may increase controllability and stability of the locomotion ( 47 , 48 ). …”

Mechanosensation and Adaptive Motor Control in Insects

“…One reason is that robots lack sensorimotor control circuits commensurate with those of animals. An important difference is that robots typically switch between explicit kinematic models to achieve different high-level behaviors, while biological systems appear to use modulation of low-level sensorimotor control loops [4]. As a result, it is difficult for a robot to find sound footholds on uneven terrain, or to extricate itself when it becomes stuck.…”

It's Not a Bug, It's a Feature: Functional Materials in Insects

“…Honeybees flying at high T b extrude a water droplet from their mouth, as do bees at ambient temperatures above 46 °C, to lower T b by as much as 5 °C. [409,410] Malaria-transmitting mosquitoes, Anopheles sp., whose preferred T b is ≈30 °C, thermoregulate each time they take a blood meal on a warm-blooded animal by emitting a droplet composed of urine and fresh blood that they keep attached to their anus. The liquid of the drop evaporates and dissipates the excess heat gained from ingesting a relatively large volume of warm blood.…”