- A History of Increasing Complexity
- Mechatronic System Organization
- Amplifiers and Isolation
- Scope: The Unit Machine
- Real-Time Software
- Nasty Software Properties
- Engineering Design and Computational Performance
- Control System Organization
- Software Portability
- Operator Interface
- Multicomputer Systems: Communication
- The Design and Implementation Process
1.2 Mechatronic System Organization
Developments in electronics have made it possible to energetically isolate the four components making up a controlled mechanical system (figure 1-2).
Figure 1-2. Parts of the
Once isolated from the instruments on one side and the actuators on the other, computation can be implemented using the most effective computing medium available. There is no need to pass a significant amount of power through the computational element. The computing medium is now the digital computer, and the medium of expression for digital computers is software.
This ability to isolate is recent. Watt's speed governor, for example, combined the instrument, computation, and actuation into the flyball element. Its computational capability was severely limited by the necessity that it pass power from the power shaft back to the steam valve. Other examples in which computation is tied to measurement and actuation include automotive carburetors, mastered cam grinders, tracer lathes, DC motor commutation, timing belts used in a variety of machines to coordinate motion, rapid transit car couplings (which are only present to maintain distance; cars are individually powered), and myriad machines that use linkages, gears, cams, and so on to produce desired motions. Many such systems are being redesigned with software-based controllers to maintain these relationships, with associated improvements in performance, productivity (due to much shorter times needed to change products), and reliability. Some, such as transit car couplings, retain traditional configurations for a variety of reasons including cost, a lack of need for the added flexibility, and customer acceptance problems.