1. COMP322/S2000/L261 Geometric and Physical Models of Objects Geometric Models l defined as the spatial information (i.e. dimension, volume, shape) of objects in the workspace. l e.g. a spherical ball, a cube, a pyramid, etc. l determine the positions and orientations of the robot arm in pick-and-place operations l can be computed in “real time” if suitable sensors and software are available. Physical Models l give the properties of the objects, i.e. mass, inertia, coefficient of friction of the material of the objects; l determine the type of robots to be used, e.g. the speed, payload, etc. l usually given or defined by the designer of the assembly task

2. COMP322/S2000/L262 Geometric and Physical Models of Objects l Objects can have the same geometric model but different physical model (and vice versa) l e.g. a sperical ball can be made of marble or iron

3. COMP322/S2000/L263 Geometric Model (3D) Reconstruction Sensors: m Laser range scanner m Stereoscopic imaging (use of 2 digital cameras) Range Scanner m Light source is usually laser (either point or line) m Digital camera to capture images of points of lines m Result is a set of very dense (high resolution) 3D points, referred to as point cloud. m Careful calibration of camera and laser are necessary m Question: How to “make sense out of these points? m One possibility is to “order” these point “along” the z-axis and utilize visualization tools to view the object.

4. COMP322/S2000/L264 Geometric Model (3D) Reconstruction Stereo Imaging l simulate human eyes (stereo vision) l use of at least 2 cameras l (refer to lecture notes on stereo-imaging.ppt)