Contents. Magnetic Motion Capture System Application for Posture Measurement Application for Dexterous Finger Measurement.

Transcription

1 Kazutaka Mitobe Akita University, Japan Contents Magnetic Motion Capture System Application for Posture Measurement Application for Dexterous Finger Measurement Hand MoCap Learning system Conclusions 1

2 A convenient posture measurement tool Magnetic vs. Optical Magnetic flux Electromagnetic Induction Infrared light Triangulation Method Magnetic MoCap Optical MoCap 2

3 Advantage of Magnetic MoCap Easy setup Rigid setup Receivers (MoCap) Transmitter (MoCap) Magnetic MoCap Optical MoCap Advantage of Magnetic MoCap A human body is transparent against the magnetic flux. Light is blocked by the human body. Occlusion! Magnetic MoCap Optical MoCap 3

4 Advantage of Magnetic MoCap Six degrees of freedom Receiver Three degrees of freedom Marker (x, y, z) Marker2 (x 2, y 2, z 2 ) (x, y, z) (Yaw, Pitch, Roll) Marker3 (x 3, y 3, z 3 ) Calculated Value (Yaw, Pitch, Roll ) Transmitter Magnetic MoCap Optical MoCap Advantage of Magnetic MoCap High spatial resolution D < 600mm, Liberty TM Position[mm] Angle[deg] Accuracy Resolution Low spatial resolution Position[mm] Accuracy >1 Resolution >1 Magnetic MoCap Optical MoCap 4

5 Disadvantage of Magnetic MoCap Receiver size: > 9mm Receiver weight: >2g Wired Marker size: > 2mm Marker weight: >0.1g Wireless Measurement area: narrow Influence by metal measurement area: wide No influence by a metal measurement of the fine motor movement of a person in a narrow space. Magnetic MoCap measurement of many people s gross movements in a wide space. Optical MoCap Notandums of Magnetic MoCap Distortion effect of eddy current Transmitter d p Receiver No measurable effect Magnetic field drops rapidly! Conductor Eddy current d > 3p usually no measurable effect 5

6 Contents Magnetic Motion Capture System Application for Posture Measurement Application for Dexterous Finger Measurement Hand MoCap Learning system Conclusions 6

7 Experimental Setup to Measure Walking 計測用 PC Receivers 9 Liberty Liberty 8 system Transmitter X Y Z Measurement Environment 7

8 Trajectory for Parts of the Body front backward Head Neck Waist Left knee Left instep Left toe Right knee Right instep Right toe Trajectory for Parts of the Body upper front Head Neck Waist Left knee Left instep Left toe lower left right backward left right Right knee Right instep Right toe Back view (X-Z plane) Top view (X-Y plane) 8

9 Head and Neck Trajectory Head Neck Head Neck World coordinate. (Origin is transmitter) Local coordinate. (Origin is receiver on the neck ) Left Knee Trajectory (Origin is receiver on the waist) X Y Z Knee Back Front 9

10 With virtual reality technology Pedestrian Simulator Setup 100inch screens Receivers (MoCap) Projectors Speaker Switch L Treadmill Switch R Control system Transmitter (MoCap) 10

11 Measurement Environment One-lane roadway Crossroad Contents Magnetic Motion Capture System Application for Posture Measurement Application for Dexterous Finger Measurement Hand MoCap Learning system Conclusions 11

12 Receiver W H L Pen L9.6 W9.6 H9.6 [mm] Weight : 2.0 [g] Right Hand 12

13 -200 Z position [mm] X position [mm] Y position [mm] X position [mm] Nib Receiver on distal phalanx of thumb. Receiver on distal phalanx of index finger. Receiver on distal phalanx of middle finger Y position [mm]

14 Pianist Surgeon High resolution CG animation using 3D data. However, it looks like a video movie. 14

15 Measurement System for Master Data Block diagram of the measuring system for master data. Measuring scene of master data. CG of the Master s Hands Based on the MoCap Data 15

16 Experimental Setup of the Learning System for Dexterous Hand Operation Block diagram of the learning system. Visual image presented by the optical see-through head-mounted display. Learning System for Dexterous Hand Operation 16

17 Video vs. Our Learning System Video projected on the screen Virtual teacher s hand on the KOTO Time lag of playing the KOTO between the master and the subject. (n=8, **P<0.01) Cross-correlation values between the movements of master s thumb fingertip and the subject s. (n=8, **P<0.01, ***P<0.005) 17

18 Conclusions In this seminar, an overview of the magnetic MoCap system was provided as a convenient posture-measurement tool. Magnetic MoCap offers the advantage of high-resolution measurement in a narrow space. It is necessary to maintain a distance from high conductivity objects. You can download our measurement program free from following website. Thank You for your kind attention You can download our measurement program free from following website. 18