550 Vol. 32 No. 6, pp.550 557, 2014 1 2 3 4 Saddle Type Human Body Motion Interface for Personal Mobility Vehicle Sho Yokota 1, Hiroshi Hashimoto 2, Daisuke Chugo 3 and Kuniaki Kawabata 4 This paper proposes the human body motion interface for personal mobility vehicle including the user s twisting motion. First, saddle is attached on the personal mobility vehicle using the seat post which has the universal joints at the attachment portion. The universal joints have three rotational joints where the potentio meters are attached on each. By hip motion, the joints are moved. The potentio meters detect these rotations. Next, we introduced the sigmoid function to connect the motion of hip and the velocity of the personal mobility vehicle. Finally, the experiment was conducted to confirm the usability. In the experiment, the control interface was prepared which doesn t use the twisting motion of the hip. The subjects drive the personal mobility vehicle on the figure 8 course layout by using proposed interface and control interface. The lap times were measured in both interface and compared. After driving the vehicle, the paired preference test was conducted. The lap time using proposed interface was shorter than the control interface, and the paired preference test showed the proposed interface is intuitive. Key Words: Intuitive, Psychometric Function, Twisting motion, Universal Joint 1. PMV Personal Mobility Vehicle PMV Segway [1] Winglet [2] U3-X [3] [4] [5] [6] PMV [7] 2013 9 10 1 2 3 4 1 Faculty of Science and Engineering, Toyo University 2 Master Program of Innovation for Design and Engineering, Advanced Institute of Industrial Technology 3 School of Science and Engineering, Kwansei Gakuin Uniersity 4 Global Research Cluster, RIKEN [8] PMV 2 1 2 Fig. 1 x, y 1 Fig. 1 θ PMV PMV JRSJ Vol. 32 No. 6 60 July, 2014
551 Fig. 1 The concept of the proposed human body motion interface for PMV 2 3 4 Fig. 2 Table 1 The coordinate system of the PMV Specifications of the personal mobility Width 70 [mm] Wheel Radius 19 [mm] Weight capacity 80 [kg] Actuator DC brush motor (90 [W] 2) Power source Ni-MH battery (24 [V] 6.7 [Ah]) 2. PMV 2 Fig. 2 Fig. 2 W [m] R[m] PMV PMV v ref [m/s] ω ref [rad/s] ω r, ω l [rad/s] 1 2 v ref = R(ω l + ω r) 2 ω ref = R(ωr ω l) 2W 1 2 v ref, ω ref ω r, ω l ω r = v ref + ω ref W R ω l = v ref ω ref W R 3 4 v ref ω ref PMV Table 1 Fig. 3 PC OKA- D-102N v ref ω ref PID Fig. 3 System configuration of the mobile platform 3. PMV PMV PMV PMV [9] x y PMV 2 PMV 2 x, y 1 θ PMV 32 6 61 2014 7
552 Fig. 5 Joint configuration at the root of the saddle Fig. 4 Saddle type Human Boddy Motion Interface KINECT KINECT Fig. 4 PMV PMV 3 Fig. 5 x, y ±π/4 [rad] θ ±π/2 [rad] PMV 3. 1 x y θ Fig. 5 AD PMV PC Fig. 6 System configuration of the PMV with suddle type human body motionn interface PMV Fig. 6 x y θ x[rad] y[rad] θ[rad] PC PMV v ref [m/s] ω ref [rad/s] PMV x[rad] y[rad] θ[rad] v ref [m/s] ω ref [rad/s] 3. 2 PMV e x e y e θ e x x x 0 e y = y y 0 θ θ 0 e θ 5 x 0 [rad] y 0 [rad] θ 0 [rad] PMV PMV v ref ω ref v ref = f 1 (e x ) ω ref = f 2(e y) + f 3(e θ ) 6 7 PMV v ref e x f 1 ω ref JRSJ Vol. 32 No. 6 62 July, 2014
553 e y f 2 e θ f 3 PMV PMV PMV f 1 f 2 f 3 f 1 f 2 f 3 PMV e x = 0 e y = 0 e θ = 0 PMV 3. 2. 1 6 20 11 1 Fig. 7 x Fig. 7 E f E f e x Fig. 7 The transition of the joint angle in case of leaning forward and returning Fig. 8 The average of the offset in each body motion E f E b E l E r E tl E tr f b l r tl tr E f E b E l E r E tl E tr e x e x e y e y e θ e θ Fig. 8 Fig. 8 Back 3. 2. 2 Psychometric Function S [10] [11] Psychometric Function 6 7 f 1 f 2 f 3 v ref 32 6 63 2014 7
554 ( ) af = 1 Kf e x d f ln v ref 1, if e x 0 ( ) a b = 1 e x +d b ln Kb v ref 1, if e x < 0 12 a f = 44.97 a b = 46.97 f 1 (e x ) = 0.3 1+e 44.97(e x 0.1309), if e x 0 0.15, if e 1+e 46.97( ex 0.1309) x < 0 13 Fig. 9 The conceptual relationship between v ref and e x f 1(e x) = 1 Kf 1+e a f (e x d f ), if e x 0 1 K b, 1+e a b ( ex d b ) if e x < 0 8 e K f K b a f a b d f d b Fig. 9 e x v ref e x v ref e x v ref e x v ref Fig. 9 E b E f E f E b E l E r E tl E tr Fig. 8 E b = 15[%] E f = 7.5[%] E l = E r = E tr = E tl = 10[%] % 9 10 11 v ref K f K b a f a b d f d b e x E b e x E f 0 v ref 0 0 v ref 0.002 [m/s] K f = 0.3 [m/s] K b = 0.15 [m/s] e x e xmax = π/12 [rad] e xmin = π/12 [rad] d f d B 1/2 d f = π/24 d B = π/24 [rad] 9 10 E f = 0.075e xmax E b = 0.15e xmin a f a b 8 a f a b ω ref f 2 f 3 f 2 f 3 2 1 Kl f 2(e y) 1+e = a l (e y d l ), if e y 0 1 K r 1+e a r ( ey dr ), if e y < 0 14 1 Ktl, if e 1+e f 3 (e θ ) = a tl (e θ d tl ) θ 0 1 K tr, if e 1+e a tr ( e θ d tr ) θ < 0 15 K a d r l tr tl K l = K r = K tl = K tl = 0.4 [rad/s] e y e ymax = π/12 [rad] e ymin = π/12 [rad] e θ e θmax = π/6 [rad] e θmin = π/6 [rad] 11 E l = 0.1e ymax E r = 0.1e ymin E tl = 0.1e θmax E tr = 0.1e θmax ω ref 0 f 2 0.005 [rad/s] f 3 0.005 [rad/s] f 1 a l a r a tl a tr 2 0.4 1+e f 2 (e y ) = 41.73(e y 0.1309), if e y 0 0.4 1+e 41.73( e y 0.1309), if e y < 0 16 0.4, if e 1+e f 3 (e θ ) = 20.86(e θ 0.2618) θ 0 0.4, if e 1+e 20.86( e θ 0.2618) θ < 0 17 6 7 13 16 17 4. JRSJ Vol. 32 No. 6 64 July, 2014
555 θ[rad] θ PMV 7 ω ref = 2f 2(e y) 18 PMV ω PMV v 13 4. 1 Fig. 10 [12] 2 ISO 5495 [13] 12 20 Fig. 10 The course layout of the experiment Fig. 11 Lap time with / without twist motion 5 4. 2 12 Fig. 11 Fig. 11 12 t p = 7.8 10 5 < 0.05 Fig. 11 Table 2 11 2 32 6 65 2014 7
556 Table 2 The number of answers Proposed interface is intuitive Result of interview The number of answers Control interface is intuitive 11 1 Fig. 14 The running trajectries by the interface including twist motion Fig. 12 The environment of the supplemental experiment Fig. 13 The course layout of the supplemental experiment Fig. 15 The running trajectries by the interface not including twist motion p = 0.006 < 0.05 2 4. 3 PMV Fig. 10 PMV Fig. 12 Fig. 13 10 [m] 4 PMV Fig. 14 Fig. 15 x 10 [m] Fig. 14 Fig. 15 Fig. 16 The average of standard error of regression line Fig. 16 5. PMV PMV PMV PMV JRSJ Vol. 32 No. 6 66 July, 2014
557 2 PMV [ 1 ] Segway, http://www.segway.com/, last accessed on Sep. 9th 2013. [ 2 ] TOYOTA Winglet, http://www.toyota.co.jp/jpn/tech/personal mobility/winglet.html, last accessed on Sep. 9th 2013. [ 3 ] HONDA UNI-CAB, http://www.honda.co.jp/robotics/u3x/, last accessed on Sep. 9th 2013. [ 4 ] N. Tomokuni and M. Shino: Wheeled Inverted-Pendulum- Type Personal Mobility Robot with Collaborative Control of Seat Slider and Leg Wheels, Proc. of 2012 IEEE/RSJ International Conference on Intelligent Robots and Systems, pp.5367 5372, 2012. [ 5 ] C. Nakagawa, K. Nakano, Y. Suda and Y. Hirayama: Steering performance of an inverted pendulum vehicle with pedals as a personal mobility vehicle, Theoretical and Applied Mechanics Letters, vol.3, issue 1, DOI:10.1063/2.1301309, 2013. [ 6 ] 2 12 pp.2010 2013, 2011. [ 7 ] S. Yokota, H. Hashimoto, Y. Ohyama and J. She: Electric Wheelchair Controlled by Human Body Motion Classification of Body Motion and Improvement of Control Method, Journal of Robotics and Mechatronics, vol.22 no.4, pp.439 446, 2010. [ 8 ] S. Yokota, H. Hashimoto, D. Chugo and K. Kawabata: Anthropomorphic Motion Design on Non-Holonomic Vehicle for Intuitive Interface, International Journal of Advanced Robotic Systems, vol.9, DOI: 10.5772/53785, 2012. [ 9 ] vol.24, no.4, pp.533 542, 2006. [10] S.S. Stevens: Psychphsics: Introduction to Its Perceptual, Neural, and Social Prospects. John Wiley and Sons, 1975. [11] T. Amemiya, H. Ando and T. Maeda: Virtual Force Display: Direction Guidance using Asymmetric Acceleration via Periodic Translation Motion, Proc. of the First Joint Eurohaptics Conference and Symposium on Haptic Interface for Virtual Environment and Teleoperator Systems, 2005. [12] Jakob Nielsen 1999. [13] 1985. Sho Yokota 2006 2008 2006 2007 2009 2010 2014 4 Ph.D. IEEE Hiroshi Hashimoto 1988 3 4 1990 2008 4 / e-learning IEEE Daisuke Chugo 2005 3 4 2006 6 2007 4 2009 4 2013 4 IEEE Kuniaki Kawabata 1997 1997 2000 2002 2005 2007 2011 10 -XJTU 2013 4 -XJTU 2002 2005 FA 2013 IEEE 32 6 67 2014 7