机电一体化系统英文文献和中文翻译(4)

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7 Conceptual rule of symbolic representation of mechatronic system scheme

For a specific mechatronic system, we first define the overall function and then gradually decompose the overall function to the sub functions until function units can directly get their function carriers, which are also called physical entities or design parameters.

On the function unit layers, the following rules can aid the scheme representation of mechatronic system.

1. First search generalized executive mechanisms that produce motion functions and then search sensing and testing subsystems and controller subsystems.

2. Use corresponding graphical symbols to represent these function units.

3. Defining the effects produced by function units and using graphical symbols to represent these effects.

4. Identify qutthree flows and use them to link corresponding input ports and output ports.

5. Ensuring continuity and completeness of three flows.

6. Define interaction relations and logical relations among the function units and use corresponding symbols to represent them.

7. Identify every function unit blocks of scheme representation system for subsequent system scheme design. We can query corresponding function carriers by means of related knowledge bases, and further get scheme solutions of mechatronic system.

8 Case study of scheme representation of mechatronic system

8.1 The scheme representation of machine tools

According to the rules mentioned in Sect. 7, the motion function of machine tools can first be pided into two kinds of motions: spindle rotating and tool head translating. Secondly, a temperature sensor and a linear displacement sensor are needed to test the spindle temperature and tool slide displacement, respectively. The parameters tested by sensors need control devices to control. Thirdly, we look for inter action relation and logical relation among function units. For

example, F3, moving tool slide leads to Harmful Effect: Motion errors, to eliminate this negative effect, F6, Control motion is introduced. Lastly, we link various function units by three flows.

8.2 The scheme representation of a multipurpose sewing machine

8.2.1 Existing scheme representation of the multipurpose sewing machine

Multipurpose sewing machines are gradually replacing ordinary sewing machines. The difference between multipurpose sewing machines and ordinary sewing machines lies in the fact that the multipurpose sewing machine has a transverse needle mechanism and several sensors and control devices. According to different oscillating motion rules of the transverse needle, the multipurpose sewing machine can sew various complex and beautiful thread traces.

At present, for the multipurpose sewing machine, designers mostly survey and imitate advanced scheme design and then express these design schemes by means of diagrammatic sketch.

This diagrammatic sketch is visual and intuitive, but can’t express interaction relations and connecting

8.2.2 A new scheme representation of the multipurpose sewing machine

According to the rules mentioned in Sect. 7, we first perform the function and action process decomposition of the multipurpose sewing machine We can find five kinds of generalized executive motion function modulars. They are piercing clothes motion, thread pick-up motion, hooking thread motion, feeding clothes motion, transverse needle oscillating motion. Secondly, we need to look for sensing and testing sub functions and control sub functions. For the piercing clothes motion, a linear movement sensor and a temperature sensor is needed to test the clothes piercing depth and temperature, respectively. For the transverse needle oscillating motion, a range sensor is needed to test transverse stitch length. For the feeding clothes motion, a range sensor is needed to test straight stitch length. The parameters tested by sensors need control devices to control. Thirdly, we look for interaction relations and logical relations among function units, such as the combined action between transverse needle motion and feeding clothes motion produces useful needle tracking. The combined action among hooking thread motion, thread pick-up motion and piercing clothes motion produces sewing. The harmful effect, “reversible error,” needs to introduce additional function unit modulars to eliminate this harmful effect. Lastly, we link various function units by three flows.