Modeling discrete and rhythmic movements through motor primitives: a review

Abstract

Rhythmic and discrete movements are frequently considered separately in motor control, probably because different techniques are commonly used to study and model them. Yet, an increasing interest for a comprehensive model for movement generation requires to bridge the different perspectives arising from the study of those two types of movements. In this article, we consider discrete and rhythmic movement within the framework of motor primitives, i.e. of modular generation of movements. Thereby we hope to get an insight into the functional relationships between discrete and rhythmic movements and thus into a suitable representation for both of them. Within this framework we can define four possible categories of modeling for discrete and rhythmic movements depending on the required command signals and on the spinal processes involved in the generation of the movements. These categories are first discussed relatively to biological concepts such as force fields and central pattern generators and are then illustrated by several mathematical models based on dynamical system theory. A discussion on the plausibility of theses models concludes this work.

A Human-Robot Interaction Based Coordination Control Method for Assistive Walking Devices and an Assessment of Its Stability

“…We believe that the CPG network-based framework presented in this article nicely complements other approaches based on compliance [28][29][30][31], adaptation [28,32,33], or adaptive learning of a dynamical model for the task at hand [34]. In particular, our approach relies on the concept of motor primitives, which first emerged in biology [35,36] and is now extensively used in robotics [37]. Assistive and rehabilitation robotics fall within the overlap between both fields and should therefore be an ideal testbed for the concept.…”

An online gait generator for quadruped walking using motor primitives

“…The concept of primitives, motor primitives or movement primitives comes from biological research, which means basic elements that can generate complicate movements. 16 In this article, we use DMP as a strategy to control a quadruped robot. A DMP-based controller is established to achieve movement, and the output signal is explained in leg coordination Cartesian space.…”

Toward simple control for complex, autonomous robotic applications: combining discrete and rhythmic motor primitives

“…Several authors have studied the interaction of discrete and rhythmic movements, sometimes reaching different conclusions, as we reviewed in Degallier and Ijspeert (2010). In this article, we consider discrete and rhythmic movements as two basic types of movements that can be combined to generate hybrid trajectories.…”

“…Here our focus is the generation of trajectories given simple, explicit high-level commands, as for instance in Maufroy et al (2008) for locomotion and Bullock and Grossberg (1988) and Hersch and Billard (2008) for reaching. The novelty here is that we address the generation of both discrete and rhythmic movements through the same system, a subject that as received little attention so far, as we reviewed in Degallier and Ijspeert (2010). Indeed, to the best of our knowledge, two main models for the simultaneous production of both discrete and rhythmic movements have been presented before, namely the models by De Rugy and Sternad (2003) and by Schaal et al (2000), and they have never been applied to robotic control.…”