Page 160 - Robotics Designing the Mechanisms for Automated Machinery
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148 Kinematics and Control of Automatic Machines
FIGURE 4.44 Layout of an electric limit switch: a) Circuit closed
by the fed wire 1; b) Reed relay: left—free of magnetic field,
right—under magnetic field; c) Mercury-actuated switch.
mercury covers both contacts, closing the electric circuit. Otherwise the contacts are
disconnected. This switch is convenient for control of angular displacement.
4.4 Dynamic Accuracy
Up to now, we have discussed the problem of motion at the level of kinematics,
without taking into account elastic deformation of the links in the mechanism. This
section deals with the problem of motion errors caused by dynamics. It is convenient
to use, for this example, the cam mechanisms we discussed above as an illustration.
We have already mentioned that the position function of these mechanisms can be
