History of Robotics Research and Development of Japan2008SensingDevelopment of high-speed optical components for robot vision

Hiromasa OkuGunma University
Masatoshi IshikawaThe University of Tokyo
A high-speed liquid lens named "Dynamorph Lens" with milli-second order response and practical optical performance for image processing, and a high-speed gaze direction control unit named "Saccade Mirror" with also milli-second response and high optical performance were developed. In this article, these are called high-speed optical components. The Dynamorph Lens change its focal length by deforming a liquid-liquid interface using a piezo-stack actuator. The minimum step response time of the focal length was 2 ms. Conventional camera lenses do focusing and zooming by changing the focal length. And, milli-second high-speed response of focusing and zooming could be achieved using the Dynamorph Lens. The Saccade Mirror is an optical component to control the gaze direction of a camera using two automated rotational mirrors. High-speed step response of 3.5 ms for 40 deg. due to the small inertia of the mirrors and full high-definition imaging quality were demonstrated. Wide field of view even with small mirrors was achieved by using so-called pupil-shift lens system. These results indicates that the frame-by-frame control of the focal length, zoom ratio, and gaze direction is possible. This would lead way to new image processing methods by intensive control of optical systems and producing a new research field. Actually, high-speed autofocusing of 15.8ms and high-speed focus tracking on a dynamic object were reported based on the coupling of the Dynamorph Lens and high-speed image processing [2]. And, a high-speed tracking of a flying ball hit by a racket using the Saccade Mirror and high-speed image processing was reported [1]. The high-speed optical components have wide applications, such as arbitrarily focused video synthesis [4], and three-dimensional motion estimation etc. 24th RSJ Best Paper Award in 2010 27th RSJ Best Paper Award in 2013.  
High-speed Tunable Lens (Dynamorph Lens) and High-speed Gaze Controller (Saccade Mirror)


Correspondence papers

Kohei Okumura, Hiromasa Oku, and Masatoshi Ishikawa:Optical Gaze Control System to Realize More High-speed Active Vision

Journal of the Robotics Society of Japan, Vol. 29, No. 2, pp. 201-211, 2011 (in Japanese).

Hiromasa Oku, Takahiko Ishikawa, and Masatoshi Ishikawa:High-Speed Focusing Vision: Coupling of Image Processing System with Tunable Optics without Speed Bottleneck

Journal of the Robotics Society of Japan, Vol. 27, No. 7, pp. 739-748, 2009 (in Japanese).

Related papers

[1] Kohei Okumura, Hiromasa Oku and Masatoshi Ishikawa : High-Speed Gaze Controller for Millisecond-order Pan/tilt Camera, Proc. 2011 IEEE International Conference on Robotics and Automation, pp.6186-6191 (2011)

[2] Hiromasa Oku and Masatoshi Ishikawa : High-Speed Liquid lens for Computer Vision, Proc. 2010 IEEE International Conference on Robotics and Automation, pp.2643-2648 (2010)

[3] Hiromasa Oku and Masatoshi Ishikawa : High-speed liquid lens with 2 ms response and 80.3 nm root-mean-square wavefront error, Applied Physics Letters, Vol.94, 221108 (2009)

[4] Hiroki Deguchi, Hiromasa Oku, Masatoshi Ishikawa : Arbitrarily Focused Video Using High-speed Liquid Lens (Posters), 5th ACM SIGGRAPH Conference and Exhibition on Computer Graphics and Interactive Techniques in Asia (SIGGRAPH ASIA 2012)

[5] Kohei Okumura, Hiromasa Oku and Masatoshi Ishikawa : Lumipen: Projection-Based Mixed Reality for Dynamic Objects, Proc. 2012 IEEE International Conference on Multimedia and Expo, pp.699-704 (2012)

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