Robotic Free Writing of Chinese Characters via Human–Robot Interactions

Abstract

Implementation of robotic writing ability is recognized as a di±cult task, which involves complicated image processing and robotic control algorithms. This paper introduces a novel approach to robotic writing by using human-robot interactions. The method applies a motion sensing input device to capture a human demonstrator's arm trajectories, uses a gesture determination algorithm to extract a Chinese character's strokes from these trajectories, and employs noise¯ltering and curve¯tting methods to optimize the strokes. The approach displays real-time captured trajectories to the human demonstrator; therefore, the human demonstrator is able to adjust his/her gesture to achieve a better character writing e®ect. Then, our robot writes the human-gestured character by using the robotic arm's joint values. The inverse kinematics algorithm generates the joint values from the stroke trajectories. Experimental analysis shows that the proposed approach can allow a human to naturally and conveniently control the robot in order to write many Chinese characters. Additionally, this approach allows the robot to achieve a satisfactory writing quality for characters with a simple structure, with the potential to write more complex characters.

A robot calligraphy system: From simple to complex writing by human gestures

“…The work reported in [14] successfully supported free writing without repeated training or complex programming. However, because the robotic arm simply followed the demonstrator's movements, it was very difficult to improve the writing quality of the strokes.…”

“…It is very useful for robots to acquire new skills without the need of complex programming and implementations [11]. Human users also prefer a convenient and natural way to directly control robots to copy characters and letters [12,13,14]. In particular, applying pen-tablets to obtain trajectory information [15] is also a fast and even more natural way to write [16,17,18].…”

“…This paper proposes a novel approach to robotic handwriting based on our initial preliminary work [20,14]. In the previous work, all the strokes had to be pre-programmed by human engineers, and only the writing actions were controlled through direct human gestures.…”

Enhanced Robotic Hand–Eye Coordination Inspired From Human-Like Behavioral Patterns

“…Robots with multiple-joint arms, or manipulators, are widely used within both industry and daily life [7]. Robotic hand-eye coordination, or reaching ability, regarded as a basic cooperation of robotic eyes and hands/arms, is implemented by two radically different methods: (1) the mathematical approach, which employs forward or inverse kinematics [8]; and (2) the learning approach [9], which uses mainly artificial neural networks.…”

Learning diverse motor patterns with a single multi-layered multi-pattern CPG for a humanoid robot

“…Chao et al in his works in Robotic free writing used gestures and complicated image processing to write Chinese characters using humanrobot interaction. However, during the process this involved significant amount of human intervention [4]. One common thing for these earlier works in writing was that they focused on a certain domain for writing like numbers or a set of characters.…”