Integrated Design Issues in Mechatronics System

The inherent concurrency or simultaneous engineering of the mechatronics approach relies heavily on the use of system modeling and simulation throughout the design and prototyping stages. Because the model will be used and altered by engineers from multiple disciplines, it is especially important that it be programmed in a visually intuitive environment. Such environments include block diagrams, flow charts, state transition diagrams, and bond graphs. In contrast to the more conventional programming languages such as Fortran, Visual Basic, C , and Pascal, the visual modeling environment requires little training due to its inherent intuitiveness. Today, the most widely used visual programming environment is the block diagram. This environment is extremely versatile, low in cost, and often includes a code generator option, which translates the block diagram into a C (or similar) high-level language suitable for target system implementation. Block diagrambased modeling and simulation packages are offered by many vendors, including MATRIXxTM, Easy5TM, SimulinkTM, Agilent VEETM, DASYLabTM, VisSimTM, and LabVIEWTM.

Mechatronics is a design philosophy: an integrating approach to engineering design. The primary factor in mechatronics is the involvement of these areas throughout the design process. Through a mechanism of simulating interdisciplinary ideas and techniques, mechatronics provides ideal conditions to raise the synergy, thereby providing a catalytic effect for the new solutions to technically complex situations. An important characteristic of mechatronic devices and systems is their built-in intelligence that results through a combination of precision in mechanical and electrical engineering, and real-time programming integrated into the design process. Mechatronics makes the combination of actuators, sensors, control systems, and computers in the design process possible.

Starting with basic design and progressing through the manufacturing phase, mechatronic design optimizes the parameters at each phase to produce a quality product in a short-cycle time. Mechatronics uses the control systems to provide a coherent framework of component interactions for system analysis. The integration within a mechatronic system is performed through the combination of hardware (components) and software (information processing).

• Hardware integration results from designing the mechatronic system as an overall system and bringing together the sensors, actuators, and microcomputers into the mechanical system.
• Software integration is primarily based on advanced control functions.

Figure 1-3 illustrates how the hardware and software integration takes place. It also shows how an additional contribution of the process knowledge and information processing is involved besides the feedback process.

FIGURE 1-3 GENERAL SCHEME OF HARDWARE AND SOFTWARE INTEGRATION

 

The first step in the focused development of mechatronic systems is to analyze the customer needs and the technical environment in which the system is integrated. Complex systems designed to solve problems tend to be a combination of mecahanical, electric, fluid power, and thermodynamic parts, with hardware in the digital and analog form, coordinated by complex software. Mechatronic systems gather data from their technical environment using sensors. The next step is to use elaborate modeling and description methods to cover all subtasks of this system in an integrated manner. This includes an effective description of the necessary interfaces between subsystems at an early stage. The data is processed and interpreted, thus leading to actions carried out by actuators. The advantages of mechatronic systems are shorter developmental cycles,
lower costs, and higher quality.

Mechatronic design supports the concepts of concurrent engineering.

In the designing of a mechatronic product, it is necessary that the knowledge and necessary information be coordinated amongst different expert groups. Concurrent engineering is a design approach in which the design and manufacture of a product are merged in a special way. It is the idea that people can do a better job if they cooperate to achieve a common goal. It has been influenced partly by the recognition that many of the high costs in manufacturing are decided at the product design stage itself. The characteristics of concurrent engineering are

• Better definition of the product without late changes.
• Design for manufacturing and assembly undertaken in the early design stage.
• Process on how the product development is well defined.
• Better cost estimates.
• Decrease in the barriers between design and manufacturing.

However, the lack of a common interface language has made the information exchange in concurrent engineering difficult. Successful implementation of concurrent engineering is possible by coordinating an adequate exchange of information and dealing with organizational barriers to crossfunctional cooperation. Using concurrent engineering principles as a guide, the designed product is likely to meet the basic requirements:

• High quality
• Robustness
• Low cost
• Time to market
• Customer satisfaction

The benefits that accrue due to the integration of concurrent engineering management strategy are greater productivity, higher quality, and reliability due to the introduction of an intelligent, selfcorrecting sensory and feedback system. The integration of sensors and control systems in a complex system reduces capital expenses, maintains a high degree of flexibility, and results in higher machine utilization.