Many researchers studying legged locomotion have applied tools from reinforcement learning/optimal control to minimize characteristics of a walking gait, most notably the energy consumption. In this paper, we use similar tools to maximize the region of stability of the controller defined as the set of initial conditions from which the robot maintains its balance for at least 5 seconds. Experime...

A goal of robotics has been to develop mechanisms that have the efficiency and speed of wheeled robots with the terrain flexibility of legged robots. In previous work, we have proposed a unique three-legged mechanism, the rotopod, designed to integrate these two useful approaches to locomotion. In this paper, we present an analysis of the variety of gaits that can be exhibited by the rotopod. W...

Optimal gait planning is applied in this work to the problem of improving stability in quadruped locomotion. In many settings, it is desired to operate legged machines at high performance levels where rapid velocities and a changing environment make stability of utmost concern. Since gait planning still remains a vital component of legged system control design, an efficient method of determinin...

In this paper we describe a controller for 4-legged robot locomotion implemented on a 4-legged walking machine. This controller uses a ring of coupled nonlinear oscillators. It is very e cient, needing no software and only a small number of components to guarantee coordination between the leg movements leading to walking. We explain how inter-leg coordination is achieved and we show data which ...

Legged locomotion enables humans and animals to traverse difficult terrain with great agility. Their skills to overcome large obstacles are impressive and superior to those of stateof-the-art legged robots. Our motivation is therefore to develop novel control methods for quadrupedal robots to increase their performance in this regard. More precisely, we seek for motor skills for the quadruped r...

There is so far no quadruped robot that exhibits locomotion performance matching to that shown by animals every day. Both differences in general design concepts, in available materials and actuation mechanisms as well as a lack of understanding on the control of the robots’ actuators contribute to the current performance gap between robotic platforms and their biological counterparts. While for...

The ability to move in complex environments is one of the most important features of humans and animals. In this work, we exploit a bio-inspired method to generate different gaits in a bipedal locomotion system. We use the 4-cell CPG model developed by Pinto [21]. This model has been established on symmetric coupling between the cells which are responsible for generating oscillatory signals. Th...

BACKGROUND Adaptive, context-dependent control of locomotion requires modulation of centrally generated rhythmic motor patterns through peripheral control loops and postural reflexes. Thus assuming that the modulation of rhythmic motor patterns accounts for much of the behavioural variability observed in legged locomotion, investigating behavioural variability is a key to the understanding of c...

Legged locomotion on flowing ground (e.g., granular media) is unlike locomotion on hard ground because feet experience both solid- and fluid-like forces during surface penetration. Recent bioinspired legged robots display speed relative to body size on hard ground comparable with high-performing organisms like cockroaches but suffer significant performance loss on flowing materials like sand. I...

This paper deals with locomotion control of legged robots using nonlinear oscillators. The proposed control system is composed of a motion plan system and a motion control system. The motion plan system is composed of a motion generator and a trajectory generator. The nonlinear oscillators in the motion generator tune the phases through the feedback signals from the touch sensors at the tips of...