Robot Mechanisms and Mechanical Devices Illustrated - Profe Saul

276 Chapter 11 Proprioceptive and Environmental Sensing Mechanisms and Devices
LAYOUTS
With the possible exception of the whisker switch, the limit switch types
discussed above almost always require some method of extending their
reach and/or protecting them and the object being sensed from damaging
each other. There are many ways to do this. The next several figures
show various basic layouts that have their own benefits and problems.
In every sensor/actuator system, there is a time lag between when the
switch is tripped and when the actuator reacts. This time lag must be
taken into account, especially if the switch or object could be damaged.
Object, in this case, can mean something in the environment, or something
attached to the robot that is designed to detect things in the environment.
If the time lag between contact and reaction cannot be made
short enough, the layout must provide some other means of preventing
disaster. This is done by using one of three methods.
Figure11-7
Direct sensing combined with direct hard stop