Modeling of mesencephalic locomotor region for Nao humanoid robot

Purpose – The purpose of this paper is to model a motor region named the mesencephalic locomotors region (MLR) which is located in the end part of the brain and first part of the spinal cord. This model will be used for a Nao soccer player humanoid robot. It consists of three main parts: High Level Decision Unit (HLDU), MLR‐Learner and the CPG layer. The authors focus on a special type of decision making named curvilinear walking. Design/methodology/approach – The authors' model is based on stimulation of some programmable central pattern generators (PCPGs) to generate curvilinear bipedal walking patterns. PCPGs are made from adaptive Hopfs oscillators. High level decision, i.e. curvilinear bipedal walking, will be formulated as a policy gradient learning problem over some free parameters of the robot CPG controller. Findings – The paper provides a basic model for generating different types of motions in humanoid robots using only simple stimulation of a CPG layer. A suitable and fast curvilinear walk has been achieved on a Nao humanoid robot, which is similar to human ordinary walking. This model can be extended and used in other types of humanoid. Research limitations/implications – The authors' work is limited to a special type of biped locomotion. Different types of other motions are encouraged to be tested and evaluated by this model. Practical implications – The paper introduces a bio‐inspired model of skill learning for humanoid robots. It is used for curvilinear bipedal walking pattern, which is a beneficial movement in soccer‐playing Nao robots in Robocup competitions. Originality/value – The paper uses a new biological motor concept in artificial humanoid robots, which is the mesencephalic locomotor region.