Legged robots are uniquely privileged over their wheeled counterparts in their potential to access rugged terrain. However, designing walking gaits by hand for legged robots is a difficult and time-consuming process, so we seek algorithms for learning such gaits to automatically using real world experimentation. Numerous previous studies have examined a variety of algorithms for learning gaits,...

Legged robots are often used in a large variety of tasks, in different environments. The large number of degrees-of-freedom, to be controlled during these tasks, turns the online generation of trajectories in these robots very complex. In this paper, we consider a modular approach to online generation of trajectories, based on biological concepts, namely Central Pattern Generators (CPGs). We in...

Legged robots are well suited t o walk on dif icult terrains at the expense of requiring complex control syst ems to walk even on flat surfaces. But simply walking on a fiat surface is not worth using a legged robot. I t should be assumed that walking on abrupt terrain is the typical situation for a legged robot. Wi th this premise in mind, we have developed a robust controller f o r a six-legg...

The development of legged robots for complex environments requires controllers that guarantee both high tracking performance and compliance with the environment. More specifically the control of the contact interaction with the environment is of crucial importance to ensure stable, robust and safe motions. In this contribution we develop an inverse-dynamics controller for floating-base robots u...

This paper reports on the use of a new actuator, called Pleated Pneumatic Artificial Muscle, in a one dimensional set-up, it is build as a footless leg with only the knee powered by a pair of Pleated Pneumatic Artificial Muscles. The main goal of this study is the evaluation of the adaptable passive behaviour of these Artificial Muscles in a leg, which can be exploited for an energy efficient w...

|Many robot applications require legged robots to traverse rough or unmodeled terrain. This paper explores strategies that would enable legged robots to respond to two common types of surface contact error: slipping and tripping. Because of the rapid response required and the di culty of sensing uneven terrain, we propose a set of reexes that would permit the robot to react without modeling or ...

In the RoboCup four-legged league, robots mainly rely on artificial coloured landmarks for localisation. As it was done in other leagues, artificial landmarks will soon be removed as part of the RoboCup push toward playing in more natural environments. Unfortunately, the robots in this league have very unreliable odometry due to poor modeling of legged locomotion and to undetected collisions. T...

Birds, fish, and many other animals travel as a flock, school, or herd. Animals in these groups must remain in close proximity while avoiding collisions with neighbors and with obstacles. We would like to reproduce this behavior for groups of simulated creatures traveling fast enough that dynamics plays a significant role in determining their movement. In this paper, we describe an algorithm fo...

The process of finding working gaits for legged robots always, to different extents, includes manual tuning, systematic search, or optimization of control parameters. This process populates a dataset of control parameter vectors and respective robot behavior factors including body rotations, speed, duty factor, etc. Normally, targeting actuated robots and not simulated ones, these datasets are ...

Performing autonomous navigation in cluttered and unstructured terrains still remains a challenging task for legged wheeled mobile robots. To accomplish such task, online planners shall incorporate new terrain information perceived while the robot is moving within its environment. While hybrid mobility robots offer high flexibility traversing by leveraging advantages of both locomotion, effecti...