Biomimetic pupils for augmenting eye emulation in humanoid robots

Contemporary approaches in the development of humanoid robots continually neglect holistic nuances, particularly in ocular prosthetic design. The standard solid glass and acrylic eye construction techniques implemented in humanoid robot design present the observer with an inaccurate representation of the natural human eye by utilising hardened synthetic materials which prohibit pupillary dynamics. Precise eye emulation is an essential factor in the development of a greater realistic humanoid robot as misrepresentation in ocular form and function will appear distinctly prevalent during proximity face to face communication as eye contact is the primary form of interpersonal communicative processing. This paper explores a new material approach in the development of a more accurate humanoid robotic eye construction by employing natural compounds similar in structure to that found in the organic human eye to replace the traditional glass and acrylic modelling techniques. Furthermore, this paper identifies a gap in current ocular system design as no robotic eye model can accurately replicate all the natural operations of the human iris simultaneously in reaction to light and emotive responsivity. This paper offers a new system design approach to augment future humanoid robot eye construction towards achieving a greater accurate and naturalistic eye emulation.     

不同个性的情感机器人表情研究

在情感机器人研究中,不同个性的面部表情是情感机器人增强真实感的重要基础。为实现情感机器人更加丰富细腻的表情,将人类的个性特征引入情感机器人,分析个性理论和情感模型理论,得知不同个性机器人的情感强度。结合面部动作编码系统中面部表情与机器人控制点之间的映射关系,得到情感机器人不同个性的基本表情实现方法。利用Solidworks建立情感机器人脸部模型,在ANSYS工程软件中将SHFR-Ⅲ情感机器人脸部模型设置为弹性体,通过有限元仿真计算方法,对表情的有限元仿真方法进行了探究,得到实现SHFR-Ⅲ不同个性基本表情的控制区域载荷大小和仿真结果。最后,根据仿真结果,进行SHFR-Ⅲ情感机器人不同个性的表情动作实验。实验结果表明,有限元表情仿真可以指导SHFR-Ⅲ情感机器人实现近似人类的不同个性的基本面部表情。     

机器人仿生脸的三维运动仿真

本文对人类产生典型表情时眼睛、眉毛、嘴和下颌的运动过程进行了分析，统计出了各器官的运动范围。采用AutoCAD和3DS MAX设计制作出了机器人仿生脸的三维结构模型，并建立了机器人仿生脸的机构运动传递关系。通过MAXScript脚本程序实现了三维运动仿真的参数化控制，获得了几种典型表情的仿真动画。     

Facial emotion and gesture reproduction method for substitute robot of remote person

CEOs of big companies may travel frequently to give their philosophies and policies to the employees who are working at world wide branches. Video technology makes it possible to give their lectures anywhere and anytime in the world very easily. However, 2-dimentional video systems lack the reality. If we can give natural realistic lectures through humanoid robots, CEOs do not need to meet the employees in person. They can save their time and money for traveling.We propose a substitute robot of remote person. The substitute robot is a humanoid robot that can reproduce the lecturers’ facial expressions and body movements, and that can send the lecturers to everywhere in the world instantaneously with the feeling of being at a live performance. There are two major tasks for the development; they are the facial expression recognition/reproduction and the body language reproduction.For the former task, we proposed a facial expression recognition method based on a neural network model. We recognized five emotions, or surprise, anger, sadness, happiness and no emotion, in real time. We also developed a facial robot to reproduce the recognized emotion on the robot face. Through experiments, we showed that the robot could reproduce the speakers’ emotions with its face.For the latter task, we proposed a degradation control method to reproduce the natural movement of the lecturer even when a robot rotary joint fails. For the fundamental stage of our research for this sub-system, we proposed a control method for the front view movement model, or 2-dimentional model.     

A Study on Acquiring Underlying Behavioral Criteria for Manipulator Motion by Focusing on Learning Efficiency

Conventional humanoid robotic behaviors are directly programmed depending on the programmer's personal experience. With this method, the behaviors usually appear unnatural. It is believed that a humanoid robot can acquire new adaptive behaviors from a human, if the robot has the criteria underlying such behaviors. The aim of this paper is to establish a method of acquiring human behavioral criteria. The advantage of acquiring behavioral criteria is that the humanoid robots can then autonomously produce behaviors for similar tasks with the same behavioral criteria but without transforming data obtained from morphologically different humans every time for every task. In this paper, a manipulator robot learns a model behavior, and another robot is created to perform the model behavior instead of being performed by a person. The model robot is presented some behavioral criteria, but the learning manipulator robot does not know them and tries to infer them. In addition, because of the difference between human and robot bodies, the body sizes of the learning robot and the model robot are also made different. The method of obtaining behavioral criteria is realized by comparing the efficiencies with which the learning robot learns the model behaviors. Results from the simulation have demonstrated that the proposed method is effective for obtaining behavioral criteria. The proposed method, the details regarding the simulation, and the results are presented in this paper.     

State-of-the art in component technology for an animated face robot-its component technology development for interactive communication with humans

We are attempting to introduce a 3D, realistic human-like animated face robot to human-robot communication. The face robot can recognize human facial expressions as well as produce realistic facial expressions in real time. For the animated face robot to communicate interactively, we propose a new concept of 'active human interface', and we investigate the performance of real time recognition of facial expressions by neural networks (NN) and the expressionability of facial messages on the face robot. We find that the NN recognition of facial expressions and the face robot's performance in generating facial expressions are of almost same level as that in humans. We also construct an artificial emotion model able to generate six basic emotions in accordance with the recognition of a given facial expression and the situational context. This implies a high potential for the animated face robot to undertake interactive communication with humans, when integrating these three component technologies into the face robot.     

A Linear Affect–Expression Space Model and Control Points for Mascot-Type Facial Robots

A robot's face is its symbolic feature, and its facial expressions are the best method for interacting with people with emotional information. Moreover, a robot's facial expressions play an important role in human-robot emotional interactions. This paper proposes a general rule for the design and realization of expressions when some mascot-type facial robots are developed. Mascot-type facial robots are developed to enable friendly human feelings. The number and type of control points for six basic expressions or emotions were determined through a questionnaire. A linear affect-expression space model is provided to realize continuous and various expressions effectively, and the effects of the proposed method are shown through experiments using a simulator and an actual robot system.     

基于运动相似性的仿人机器人双足步行研究

提出了一种基于人体步行运动相似性的仿人机器人双足步行动作设计方法．改进了人体步行轨迹的参 数获取与相似性匹配系统,扩展了相似性函数的适用范围．根据仿人机器人的机械连杆特点定义了步行运动周期中 的关键姿势与子相变换,建立了运动学约束方程,并对行走中出现的动态稳定性问题进行了约束．仿真和实体机器 人实验验证了该方法的有效性．     

基于情感交互的仿人头部机器人

本研究的目的是设计一台机器人,使它可以与人互动,并在日常生活中和常见的地方协助人类．为了 完成这些任务,机器人必须友好地显示出一些情感,表现出友好的特点和个性．依据仿生学,研制了一台仿人头部 机器人,建立了机器人的行为决策模型．该机器人具有人类的6 种基本面部表情,以及人脸检测、语音情感识别与 合成、情感行为决策等能力,能够通过机器视觉、语音交互、情感表达等方式与人进行有效的情感交互．     

Biologically inspired design of a parallel actuated humanoid robot

This paper presents the comparison for the role of bi-articular and mono-articular actuators in human and bipedal robot legs, in particular the hip and knee joint, for driving the design of a humanoid robot with inspirations from the biological system. The various constraints driving the design of both systems are also compared. Additional factors particular to robotic system are identified and incorporated in the design process. To do this, a dynamic simulation is used to determine loading conditions and the forces and power produced by each actuator under various arrangements. It is shown that while the design principles of humans and humanoids are similar, other constraints ensure that robots are still merely inspired by humans, and not direct copies. A simple design methodology that captures the complexity and constraints of such a system in this paper is proposed. Finally, a full-size humanoid robot that demonstrates the newfound principle is highlighted.     

Facial expression recognition based on local region specific features and support vector machines

Facial expressions are one of the most powerful, natural and immediate means for human being to communicate their emotions and intensions. Recognition of facial expression has many applications including human-computer interaction, cognitive science, human emotion analysis, personality development etc. In this paper, we propose a new method for the recognition of facial expressions from single image frame that uses combination of appearance and geometric features with support vector machines classification. In general, appearance features for the recognition of facial expressions are computed by dividing face region into regular grid (holistic representation). But, in this paper we extracted region specific appearance features by dividing the whole face region into domain specific local regions. Geometric features are also extracted from corresponding domain specific regions. In addition, important local regions are determined by using incremental search approach which results in the reduction of feature dimension and improvement in recognition accuracy. The results of facial expressions recognition using features from domain specific regions are also compared with the results obtained using holistic representation. The performance of the proposed facial expression recognition system has been validated on publicly available extended Cohn-Kanade (CK+) facial expression data sets.     

Intelligent facial emotion recognition and semantic-based topic detection for a humanoid robot

Automatic perception of human affective behaviour from facial expressions and recognition of intentions and social goals from dialogue contexts would greatly enhance natural human robot interaction. This research concentrates on intelligent neural network based facial emotion recognition and Latent Semantic Analysis based topic detection for a humanoid robot. The work has first of all incorporated Facial Action Coding System describing physical cues and anatomical knowledge of facial behaviour for the detection of neutral and six basic emotions from real-time posed facial expressions. Feedforward neural networks (NN) are used to respectively implement both upper and lower facial Action Units (AU) analysers to recognise six upper and 11 lower facial actions including Inner and Outer Brow Raiser, Lid Tightener, Lip Corner Puller, Upper Lip Raiser, Nose Wrinkler, Mouth Stretch etc. An artificial neural network based facial emotion recogniser is subsequently used to accept the derived 17 Action Units as inputs to decode neutral and six basic emotions from facial expressions. Moreover, in order to advise the robot to make appropriate responses based on the detected affective facial behaviours, Latent Semantic Analysis is used to focus on underlying semantic structures of the data and go beyond linguistic restrictions to identify topics embedded in the users’ conversations. The overall development is integrated with a modern humanoid robot platform under its Linux C++ SDKs. The work presented here shows great potential in developing personalised intelligent agents/robots with emotion and social intelligence.     

A robust incremental clustering-based facial feature tracking

Emerging significance of person-independent, emotion specific facial feature tracking has been actively tracked in the machine vision society for decades. Among distinct methods, the Constrained Local Model (CLM) has shown significant results in person-independent feature tracking. In this paper, we propose an automatic, efficient, and robust method for emotion specific facial feature detection and tracking from image sequences. A novel tracking system along with 17-point feature model on the frontal face region has also been proposed to facilitate the tracking of human basic facial expressions. The proposed feature tracking system keeps patch images and face shapes till certain number of key frames incorporating CLM-based tracker. After that, incremental patch and shape clustering algorithms is applied to build appearance model and structure model of similar patches and similar shapes respectively. The clusters in each model are built and updated incrementally and online, controlled by amount of facial muscle movement. The overall performance of the proposed Robust Incremental Clustering-based Facial Feature Tracking (RICFFT) is evaluated on the FGnet database and the Extended Cohn-Kanade (CK+) database. RICFFT demonstrates mean tracking accuracy of 97.45% and 96.64% for FGnet and CK+ database respectively. Also, RICFFT is more robust by minimizing average shape distortion error of 0.20% and 1.86% for FGnet and CK+ (apex frame) database, as compared with classic method CLM.     

Evaluation of active wearable assistive devices with human posture reproduction using a humanoid robot*

This study proposes a quantitative evaluation method for assessing active wearable assistive devices that can efficiently support the human body. We utilize a humanoid robot to simulate human users wearing assistive devices owing to various advantages offered by the robot such as quantitative torque measurement from sensors and highly repeatable motion. In this study, we propose a scheme for estimating the supportive torques supplied by a device called stationary torque replacement. To validate the reliability of this evaluation method by using a humanoid robot, we conducted measurements of human muscular activity during assisted motion. Analysis of the measured muscle activity revealed that a humanoid robot closely simulates the actual usage of assistive devices. Finally, we showed the feasibility of the proposed evaluation method through an experiment with the humanoid robot platform HRP-4 and the Muscle Suit active assistive device. With the proposed method, the supportive effects of the assistive device could be measured quantitatively in terms of the static supportive torque acting directly on the body of a simulated human user.     

仿人机器人相似性运动轨迹跟踪控制研究

提出一种基于带观测器的条件状态反馈控制的仿人机器人相似性运动轨迹跟踪控制方法.首先,分析了7连杆双足机器人动力学模型,阐述了其运动能量方程与动力学特征方程; 其次,基于带观测器的状态反馈控制器原理,构建起三维倒立摆平衡控制模型; 最后,由线性二次型调节器确定状态反馈增益矩阵,使机器人轨迹跟踪误差最小化,以复现出较高相似度的双足步行运动效果.实验验证了该方法的有效性.     

仿人机器人复杂动作设计中人体运动数据提取及分析方法

提出了仿人机器人复杂动作设计中人体运动数据提取及分析方法. 首先, 通过运动捕捉系统获取人体运动数据, 并采用运动重定向技术, 输出人--机简化模型的数据; 然后, 对运动数据进行分析和运动学解算, 给出基于人体运动数据的仿人机器人逆运动学求解方法, 得到仿人机器人模型的关节角数据; 再经过运动学约束和稳定性调节后, 生成能够应用于仿人机器人的运动轨迹. 最终, 通过在仿人机器人BHR-2上进行刀术实验验证了该方法的有效性.     

Online learning design of an image-based facial expression recognition system

In order to serve people and support them in daily life, a domestic or service robot needs to accommodate itself to various individuals. Emotional and intelligent human–robot interaction plays an important role for a robot to gain attention of its users. Facial expression recognition is a key factor in interactive robotic applications. In this paper, an image-based facial expression recognition system that adapts online to a new face is proposed. The main idea of the proposed learning algorithm is to adjust parameters of the support vector machine (SVM) hyperplane for learning facial expressions of a new face. After mapping the input space to Gaussian-kernel space, support vector pursuit learning (SVPL) is employed to retrain the hyperplane in the new feature space. To expedite the retraining step, we propose to retrain a new SVM classifier by using only samples classified incorrectly in previous iteration in combination with critical historical sets. After adjusting the hyperplane parameters, the new classifier will recognize more effectively previous unrecognizable facial datasets. Experiments of using an embedded imaging system show that the proposed system recognizes new facial datasets with a recognition rate of 92.7%. Furthermore, it also maintains a satisfactory recognition rate of 82.6% of old facial samples.     

Design of an android robot head for stage performances

In this article, an android robot head is proposed for stage performances. As is well known, an android robot is a type of humanoid robot which is considered to be more like a human than many others types. An android robot has human-like joint structures and artificial skin, and so is the robot which is closest to a human in appearance. To date, several android robots have been developed, but most of them have been made for research purposes or exhibitions. In this article, attention is drawn to the more commercial value of an android robot, especially in the acting field. EveR-3, the android robot described here, has already been used in commercial plays in the theater, and through these it has been possible to learn which features of an android robot are necessary for it to function as an actor. A new 9-DOF head has been developed for stage performances. The DOF are reduced when larger motors are used to make exaggerated expressions, because exaggerated expressions are more important on the stage than detailed, complex expressions. LED lights are installed in both cheeks to emphasize emotional expressions by changes in color in the way that make-up is used to achieve a similar effect on human faces. From these trials, a new head which is more suitable for stage performances has been developed.     

Face Recognition Under Occlusions and Variant Expressions With Partial Similarity

Recognition in uncontrolled situations is one of the most important bottlenecks for practical face recognition systems. In particular, few researchers have addressed the challenge to recognize noncooperative or even uncooperative subjects who try to cheat the recognition system by deliberately changing their facial appearance through such tricks as variant expressions or disguise (e.g., by partial occlusions). This paper addresses these problems within the framework of similarity matching. A novel perception-inspired nonmetric partial similarity measure is introduced, which is potentially useful in dealing with the concerned problems because it can help capture the prominent partial similarities that are dominant in human perception. Two methods, based on the general golden section rule and the maximum margin criterion, respectively, are proposed to automatically set the similarity threshold. The effectiveness of the proposed method in handling large expressions, partial occlusions, and other distortions is demonstrated on several well-known face databases.