tailieunhanh - Sensing Intelligence Motion - How Robots & Humans Move - Vladimir J. Lumelsky Part 9

Tham khảo tài liệu 'sensing intelligence motion - how robots & humans move - vladimir j. lumelsky part 9', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | 216 MOTION PLANNING FOR TWO-DIMENSIONAL ARM MANIPULATORS the sensing range will be a complex figure Figure that surrounds the arm and changes its shape as the arm links move relative to each other. In C-space the situation is somewhat closer to the mobile robot sensing range simply because in C-space the arm becomes a point. But that s where the similarity stops. Assume that the arm s sensing allows it to sense objects in W-space within some sensing range r Figure . An obstacle will be detected when it is at a distance equal to or smaller than r from the point on the arm body closest to it. With this kind of proximity sensing the robot s sensing range in C-space plane 91 92 is not a circle anymore. In fact it is not even an entity with fixed parameters. The sensing range image will look in C-space more or less like the one in Figure point C is the arm s current position . As the arm links move relative to the arm base and relative to each other the joint angles 91 92 change accordingly. The sensing range C-space image then moves in the plane 91 92 Figure In C-space the sensing range of the revolute-revolute arm has a shape similar to the one shown here. The point in the center of the figure corresponds to the values 91 92 of the arm s current position. As the arm moves in its workspace this figure moves in C -space with its shape and dimensions changing continuously. PLANAR REVOLUTE-REVOLUTE RR ARM 217 with its shape and dimensions shrinking and expanding from rectangle-like to ellipse-like and with shapes in between like in Figure . Animation of this process makes for a wonderful movie One sees a strange creature that is moving while constantly changing its shape according to some mystifying law. The extent of variability in the sensing range C-space image depends on the sensing range r and the arm s kinematics. Calculation of the sensing range C-space image is an interesting though rather involved task there are many details and many .