Research On Modelling And Realization Of Artificial Emotion For Humanoid Head Portrait Robot

With the development of the humanoid robot research application, human have more and more need for humaoid robot with emotion. The study of humanoid head robot is an important trend to realize human-computer interaction in the field of robotics. Emotion can improve the autonomy and flexibility of robot, and offer the user for feedback, such as internal state, goal and intention. At present, the research in artificial emotional model is at developing stage abroad. In China, the research is focused on theory of artificial emotional model research. There are few publications about application of the emotional model. In the present study, the software and hardware platform of humanoid head portrait robot were developed with some related techniques of personal robots. The modelling and realization of artificial emotion for humanoid head portrait robot was deeply researched through theory, simulation and experiment. The research is foundation for realizing huamn-machine interaction and coexistence of humans and robots.In the view of cognition of the psychology, artificial emotion model was presented for humanoid head portrait robot. The mathematical model of emotional expression was built to describe the emotional character. In the model, the coefficient matrix was studied to reflect the effect of emotion and personality. The emotion and emotional transiton were to descibe artificial emotion. Based on the theory of finite state machine (FSM), the hierarchical expanded finite state machine (EFSM) emotional interaction model was built. The main work in the model was finished on the bottom EFSM. In the EFSM, the variable set V was defined to offer the data for the behavior of robot. In the study of FSM, the transition table and transition matric were studied to show the emotion transition. Based on the relation FSM and Markov, the stationary probability distribution of FSM were calculaed. The emotional behavior of FSM was obtained by the transition route in the state transition graph. The simulation model was built on the basis of the artificial emotional model. The theory was verified by the simulation, which was taken as the basis for experimental study.Aimed to the extra-simulation, the extraction and recognition for visual and speech sign were researched in the human head robot system. In the visual sign, projection and knowledge were used to extract expression feature in the gray image. Fuzzy neural network (FNN) was used to recognize facial expression. In the structure of fuzzy neural network, fuzzy clustering method was adopted to adjust the center parameter, and Least square method was to adjuest the connection weights. In the speech sign, Continuous hide Markov model (CHMM) was to recognize speech words, short-time energy and short-time average zero-crossing rate to segment speech sign were adopted. A 12-order MFCC and short-time energy were defined as the static characteristic parameters, and first order difference of these parameters were defined as dynamic characteristic parameters.The humanoid head portrait robot"H&Frobot-III"with audio-visual function was developed based on the humanoid head portrait robot"H&Frobot-II". The robot includes robot body, control system and sensor system. The robot body could realize the movement of eyeball, eyelid and lip. The facial expression and basic lip shape of robot were realized by controlling the movement of feature points in the flexible skin based on facial action coding system(FACS). In the sensor system, a CCD camera and a SPCE061A chip were use to realize robot's visual and audtive function.The relative experiments were researched for emotional interaction with human and robot. Six basic facial expressions(normal, smile, surprise, digust, sad, angry) and dynamic lip were obtained by the emotional representation experiment. In these experiments, the robot was verified to express emotion through dialogue and facial expression. Based on these experiments, emotional interaction experiment was researched, the robot could respond to people's voice and facial expression. The experiment results show that robot can realize the human-machine interaction and the validity of artifiacial emotional model.Theoretical and experimental research results in this paper indicate that artificial emotion model can satisfy the need of interaction for human-robot very well.This study is a part of the research project named"Integration Design and Basic Technology Verification in the Full Body Robot System with Expression Intelligence"grant number(2006AA04Z201). Supported by the National High-Tech and Research and Development Program of China. It is also a part of project of"Interdisciplinary Foundation of HIT:"Research on Humanoid Robot with Six Facial Expression and Visual"grant number(HIT.DM.2002.0.6).