Forming the Concept of Direction Developmentally

The concept of direction is critical for a robot to establish its abilities in spatial perception. This article addresses the issue of how a robot developmentally forms the concept of direction. We propose a novel framework, based on the related mechanisms of humans, in which motion cues are employed instead of other commonly used sensing means like vision or audition. Using motion cues is actually one of the most important ways for humans to acquire concepts. This leads to advantages in two ways: 1) models based on motion cues are usually more convenient for a robot's control of motion and 2) multimodal perceptual cues can complement each other and result in improved robustness. The framework behind our methodology lies in developmentally forming the concept of direction in two successive phases: 1) the robot acquires the perceptual representation of its motion by motor babbling and 2) the corresponding higher level features are gradually captured, based on which the conceptual representation is obtained and then the concept of direction is formed. The proposed framework and the corresponding models are evaluated with a PKU-HR5.0II humanoid robot. The results show that the robot can successfully form the concept of direction in a manner similar to that of humans.