CPG-based Controllers can Generate Both Discrete and Rhythmic Movements

Abstract

Complex tasks require the combination of both discrete and rhythmic movements. Though scientists do not yet agree on the neural architecture involved in both types and in the transition from one to the other, the importance of having robot controllers able to behave rhythmically and discretely is universally recognized. In this paper, a bio-inspired robot controller based on oscillating neurons is proposed to realize both discrete and rhythmic movements and easily transition from one to the other. It is shown that, under certain parameter conditions, the CPG controller behaves like a PID controller. In order to demonstrate the feasibility of controlling both discrete and rhythmic movements, the CPG is applied to the initiation of handshaking, namely, reach towards the human hand and start to shake it. Results show that this architecture is suitable for both discrete and rhythmic movements and can easily transition from one to the other.

Comparative study of forced oscillators for the adaptive generation of rhythmic movements in robot controllers

“…Furthermore, the three oscillators are all non-linear systems, however the degree of non-linearity can be modified more easily for Rowat-Selverston and Hopf than Matsuoka. Rowat-Selverston also has a discrete mode where it behaves like a PID controller (Jouaiti and Henaff, 2018). This, however, does not seem to be possible for Hopf and Matsuoka. We feel that this study can help understand these oscillators better and for which purpose they are better suited.…”

“…The Rowat-Selverston neuron (Rowat and Selverston, 1993) is able to produce discrete and rhythmic activities depending of two parameters like shown in Jouaiti and Henaff (2018); Nassour et al (2014). Properties of the Van der Pol can be applied to it since it is a generalized Van der Pol oscillator, notably the dynamic Hebbian learning of frequency introduced by , as demonstrated in .…”

Hands to Hexapods, Wearable User Interface Design for Specifying Leg Placement for Legged Robots

“…To further compare the obstacle avoidance, a camera-based autonomous gait is designed ( Jouaiti and Henaff, 2018 ; Lee et al, 2017 ; Sun et al, 2017 ; Shaw et al, 2019 ). The input visual information is exactly the same as the camera view provided to the operator.…”

Improving Motor Coordination in HRI with Bio-Inspired Controllers

“…In the rhythmic mode, the CPG can adapt its intrinsic frequency, amplitude and synaptic weight using hebbian plasticity mechanisms [14]. This CPG also has a discrete mode where it behaves like a PID controller and it can adapt its parameters to match the input amplitude [15]. The CPG controller confers several advantages: no robot model is necessary; it can take in any kind of input (position, velocity, torque...) and it can achieve coordination through multimodal information (visual, contact...).…”