Robot Handwriting: Why and How?

Abstract

Handwriting has always been considered an important human task, and accordingly it attracted attention of researchers working in biomechanics, physiology, and related fields. There exist a number of studies on this matter. This paper considers human-machine analogy and relates robots with handwriting. The work is twofold: it improves the knowledge in biomechanics of handwriting, and introduces some new concepts in robot control. The idea is to find the biomechanical principles humans apply when resolving kinematic redundancy, express the principles by means of appropriate mathematical models, and then implement them in robots. This is a step forward in generation of human-like motion of robots. Two approaches to redundancy resolution are described: (i) “Distributed Positioning” (DP) which is based on a model appropriate to represent the arm motion in the absence of fatigue, and (ii) “Robot Fatigue” approach, where robot movements similar to the movements of a human arm under muscle fatigue are generated. Both approaches are applied to a redundant anthropomorphic robot arm performing handwriting. The simulation study includes the issues of legibility and inclination of handwriting. The results demonstrate the suitability and effectiveness of both approaches.