SPACE MOUSE

INTRODUCTION  It is a human computer interaction technology  Helps in movement of manipulator in 6 degree of freedom * 3 translation degree * 3 rotational degree  Used in task unfavorable for human * Lifting of heavy weights * In hazardous environment

TYPES BALL TYPE HAND TYPE

Major components of system 1. Image processing unit 2. Robot control unit Two different approaches 1. Using 2 camera 2. Using 1 camera

IMAGE PROCESSING UNIT Components used: >2 grayscale CCD camera >Datacube max video 20 >Processing language : VEIL Objective: To track and estimate the position of the hand

Video o/p Blurring filter Threshold Blob Detection WORKING

Record image difference of successive images Create a map Send to filter Spikes is created Control blob is selected Stored in global data Bounding box is thresholded

R OBOT CONTROL UNIT Objective >where to reach >how to reach Language used: RCCL It describe the position using Cartesian position equation or set of joint angle Consist of several transform matrices

EFFECT OF POSITION EQUATION

T START. T VARIABLE = T BASE. T 6. T TOOL T base= Homogeneous coordinate transformation from world frame to robot base frame T 6 = From base frame to a frame attached to link 6 of the robot T tool = Frame attached to link 6 to the tool frame of the robot T start= Homogeneous coordinate transform from the world coordinate frame to the initial position and orientation of the tool T vrble= Homogeneous coordinate transformation matrix that is continuously updated

TOOL.T VARIABLE.T START o Input given to this unit is blob data structure o Centre of blob contain pixel coordinate o Centre of camera is taken as origin o Pixel coordinate are converted into global coordinate o To reach a point in space > Solve for T6 in Cartesian space > Transform into joint angle o RCCL will plan a path to the point and upgrade By direct mapping robot can be moved T 6 = BASE.

A PPROACHES IN SPACE MOUSE Using 2 camera  Only one image can be processed at a time  2 camera are proposed by switching 2 video channel combined with transfer time via bus channel  It is time consuming  It reduced the hand motion in unnatural way

Using 1 camera  It consist of 3 different level >2 control level >1 transition level  Control level are used to move the manipulator  Transition level connect 2 control level and affect the gripper of robot arm

MOTION PLANES OF TWO CONTOL LEVELS

WORKING When palm of hand is facing toward or away from cameras, system is in one of control level Robot can be moved by moving hand in up-down or forward-backward direction Planes of 2 control level is orthogonal to each other These planes intersect at manipulator Palm is facing down, the system is in transition level It activate the gripper and rotating the system in vertical axis Gripper movement initiate rotating the hand in the horizontal plane

Control level 1 _____________ Plane 1 movement Transition level ______________ Gripper use rotation Control level 2 ______________ Plane 2 movement Height< height 3_4 Height>height 3_4 Height<height 3_4 STRUCTURE OF STATE MACHINE

ADVANTAGE  System is cheap  No physical wear and tear  It is flexible  It is robust  Provide upgrading possibilities DISADVANTAGE  Dark clothing and background should be used  System may not track same control blob always  It can be used only by trained workers

C ONCLUSION Space mouse is simple It can be performed with minimum training or teaching This a good demonstration in which a 3D can be operated