title: Evolution of Joint-Level Control for Quadrupedal Locomotion.
abstract: We investigate a hierarchical approach to robot control inspired by joint-level control in animals. The method combines a high-level controller, consisting of an artificial neural network (ANN), with joint-level controllers based on digital muscles. In the digital muscle model (DMM), morphological and control aspects of joints evolve concurrently, emulating the musculoskeletal system of natural organisms. We introduce and compare different approaches for connecting outputs of the ANN to DMM-based joints. We also compare the performance of evolved animats with ANN-DMM controllers with those governed by only high-level (ANN-only) and low-level (DMM-only) controllers. These results show that DMM-based systems outperform their ANN-only counterparts while also exhibiting less complex ANNs in terms of the number of connections and neurons. The main contribution of this work is to explore the evolution of artificial systems where, as in natural organisms, some aspects of control are realized at the joint level.
authors.affiliation: Grand Valley State University.
authors.forename: Jared M
authors.initials: JM
authors.lastname: Moore
authors.affiliation: Michigan State University.
authors.forename: Philip K
authors.initials: PK
authors.lastname: McKinley
mesh_terms: D000818:Animals; D005075:Biological Evolution; D007596:Joints / Q000502:physiology*; D008124:Locomotion; D008954:Models, Biological; D009132:Muscles / Q000502:physiology; D016571:Neural Networks, Computer; D009474:Neurons / Q000502:physiology; D012371:Robotics
keywords: Evolutionary robotics; artificial neural network; digital muscle; joint-level control; morphology