Horse-like walking, trotting, and galloping derived from kinematic Motion Primitives (kMPs) and their application to walk/trot transitions in a compliant quadruped robot

Abstract

This manuscript proposes a method to directly transfer the features of horse walking, trotting, and galloping to a quadruped robot, with the aim of creating a much more natural (horse-like) locomotion profile. A Principal Component Analysis (PCA) on horse joint trajectories shows that walk, trot, and gallop can be described by a set of four kinematic Motion Primitives (kMPs). These kMPs are used to generate valid, stable gaits that are tested on a compliant quadruped robot. Tests on the effects of gait frequency scaling follow: results indicate a speed-optimal walking frequency around 3.4 Hz, and an optimal trotting frequency around 4 Hz. Following, a criterion to synthesize gait transitions is proposed, and the walk/trot transitions are successfully tested on the robot. The performance of the robot when the transitions are scaled in frequency is evaluated by means of roll and pitch angle phase plots.

Pattern generation and compliant feedback control for quadrupedal dynamic trot-walking locomotion: experiments on RoboCat-1 and HyQ

“…Moro et al set an example toward this direction; they collected motion capture data from a horse and used it to generate a motion pattern for a passive compliant robot, in virtue of kinematic motion primitives (Moro et al 2013). Koolen et al proposed a legged locomotion technique based on capturability analysis (Koolen et al 2012).…”

“…A straightforward implementation in this direction is the use of physically flexible elements to obtain passively compliant locomotion cycles (Rutishauser et al 2008;Moro et al 2013;Hutter et al 2013;Kimura et al 2007;Ugurlu et al 2014;Sproewitz et al 2011). This approach is founded on observations from biological structures; it potentially increases the energy efficiency and the environmental adaptability.…”

Energy Based Position Control of Jansen Walking Robot

“…Estremera et al in [2] elaborates with simulation and experiments the development of crab and turning gaits for hexpod robot, SILO-6 deployments in demining applications often characterized by uneven terrains and forbidden zones. In [3], Federico et al proposes an approach to directly map a range of gaits of a horse to a quadruped robot with an intention of generating a more life-like locomotion cycle. The work also presents the use of kinematic motion primitives in generating valid and stable walking, trotting and galloping gaits that are tested on a compliant quadruped robot.…”

Dynamic trot-walking with the hydraulic quadruped robot — HyQ: Analytical trajectory generation and active compliance control

“…Keeping these in mind, a group of researchers directed their attention to alternative approaches. For instance, Moro and his associates use motion capture data from a horse and utilized these as kinematic motion primitives [13]. Kalakrishnan and his teammates proposed a Center of Pressure (CoP)-based trajectory generation to achieve rough terrain locomotion [4].…”