Tham khảo tài liệu 'mcgraw-hill - robot mechanisms and mechanical devices illustrated - 2003 part 13', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | This page intentionally left blank. Mechanical limit switches are devices that sense objects by being either directly or indirectly touched by the object. Most use a button lever whisker or slide as their local sensor. Two other types that warrant their own categories are the magnetic reed switch and the membrane switch which is much like a long button actuated switch. On a robot the switch alone can be the whole sensor but in most cases the switch makes up only a part of a sensor package. The limit switch can be thought of as a device that has at least one input and one output. The input is the button lever whisker or slide or for the magnetic type anything ferrous nearby . The output is almost always closing or opening an electric circuit. There are several other types of limit switches whose inputs and outputs are different than those discussed above but only those that sense by direct contact or use magnets will be included here. Other types are not strictly mechanical and are more complex and beyond the scope of this book. In a robot there are two general categories of things that the robot s microprocessor needs to know about many of which can be sensed by mechanical limit switches. The categories are proprioceptive and environmental. Proprioceptive things are part of the robot itself like the position of the various segments of its manipulator the temperature of its motors or transistors the current going to its motors the position of its wheels etc. Environmental things are generally outside the robot like nearby objects ambient temperature the slope of the surface the robot is driving on bumps or drop-offs etc. This is an over-simplified explanation because in several cases the two categories overlap in one way or another. For instance when the bumper bumps up against an object the object is in the environment environmental sensing but the bumper s motion and location relative to the robot is detected by a limit switch mounted inside the robot s body .
