Assessment of Mental Stress on Human Operators Induced by the Assembly Support in a Robot-Assisted “Cellular Manufacturing” Assembly System
Ryu Kato and Tamio Arai
Department of Precision Engineering, School of Engineering, The University of Tokyo, 7-3-1 Hongo, Bunkyo-ku, Tokyo 113-8656, Japan
For the improvement of productivity in “cellular manufacturing assembly systems,” we are now witnessing the emergence of the production support systems in which industrial robots are providing physical support and assistance to the manufacturing operations and also to the cognition of information/instruction to the human operators. In such systems, the human operators still act as the prime players who make the final decision in all facets of the operation, and the adverse effects of the mental stress on these players caused by inappropriate “support” provided by the system must be carefully considered. In view of the above, in this study, we tried to objectively assess the effects of the mental stress caused by such robot-assisted “cellular manufacturing” assembly systems using physiological indices related to cognition and emotion. Our results showed that higher speeds of an approaching robot’s motion and closer distances between human operator and industrial robot increase mental stress related to emotion, while augmenting text instruction with voice guidance and optical pointer increase mental stress related to cognition and emotion. These results provide important knowledge that can be used to formulate design guides and safety standards for reduced-stress production systems that involve human-industrial robot collaboration.
-  S. Seki, “One by One Production in the “Digital Yatai”: Practical Use of 3D-CAD Data in the Fabrication,” Journal of the Japan Society of Mechanical Engineers, Vol.106, No.1013, pp. 254-258, 2003 (in Japanese).
-  M. Sugi, et al., “Motion and Arrangement Planning for Self-Moving Trays in Human Supporting Production Cell “Attentive Workbench”,” Journal of the Japan Society for Precision Engineering, Vol.72, No.11, pp. 1380-1385, 2006 (in Japanese).
-  K. Itoh, et al., “Ergonomics Handbook,” Asakura Publishing Co., Ltd., 2004 (in Japanese).
-  M. Jindai, et al., “A Study on Robot-Human System with Consideration of Individual Preferences: 2nd Report, Multimodal Human-Machine Interface for Object-Handing Robot System (Mechanical Systems),” Transactions of the Japan Society of Mechanical Engineers. C, Vol.73, No.729, pp. 1408-1415, 2007 (in Japanese).
-  M. Zecca, M. Saito, N. Endo, Y. Mizoguchi, K. Itoh, H. Takanobu, and A. Takanishi, “Waseda Bioinstrumentation system WB-2 - the new inertial measurement unit for the new motion caption system -,” Robotics and Biomimetics 2007, pp. 139-144, 2007.
-  F. Wada, et al., “Model to Estimate User's Cognitive Load for Adaptive Information Presentation: Basic Study for Verification of Hypotheses of Model,” ITE Technical Report, Vol.25, No.29, pp. 7-12, 2001 (in Japanese).
-  A. Kashihara, et al., “A Cognitive Load Application in Explanation and Its Evaluation,” Journal of Japanese Society for Artificial Intelligence, Vol.10, No.3, pp. 393-402, 1995 (in Japanese).
-  J. Too Chuan Tan, et al., “Assembly information support system for operational support in cell production,” The 41th CIRP conference on manufacturing system, pp. 209-212, 2008.
-  Y. Fujigaki, “The truth of standardization and direction of mental workload research,” The Japanese Journal of Ergonomics, Vol.29, No.6, 1993 (in Japanese).
-  T. Hagiwara, et al., “Effects of Cellular Telephone Use while Driving based on Mental Workload Assessment,” IATSS review, Vol.30, No.3, pp. 66-72, 2004 (in Japanese).
-  K. Kotani, et al., “Workload Control Using the Real-time Extraction of Respiratory Sinus Arrhythmia,” Transactions of the Japanese Society for Medical and Biological Engineering, Vol.43, No.2, pp. 252-260, 2005.
-  K. Hashimoto, “Physiological meaning of the critical flicker frequency (CFF) and some problems in their measurement: Theory and practice of the flicker test,” Japanese Journal of Industrial Health, Vol.5, No.9, pp. 563-578, 1964 (in Japanese).
-  R. Ikeura, et al., “Study on emotional evaluation of robot motions based on galvanic skin reflex,” The Japanese Journal of Ergonomics, Vol.31, No.5, pp. 355-358, 1995 (in Japanese).
-  R. Ikeura, et al., “Prior notice method of robotic arm motion for suppressing a threat to a human,” advanced robotics: the international journal of the Robotics Society of Japan, Vol.14, No.5, pp. 415-417, 2000.
-  S. G. Hart, et al., “Development of NASA-TLX (Task Load Index): Results of Empirical and Theoretical Research,” In P. A. Hancock and N. Meshkati (Eds.). Human mental workload. North Holland Press, Amsterdam, The Netherlands, pp. 239-250, 1988.