机电一体化模型英文文献和中文翻译(5)

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What we have gained so far is establishing a consistent and complete mathematical description of mechatronics system model by using arrays to identify the properties of the whole system. The interface between the submodels is kept as simple as possible by employing simple mapping functions.

4. SIMULATION

Considering that the whole system is at rest and the boring spindle is at the rear position and the user has just pressed start button. The combination of input signal from the breakers and from the interface with the physical system will cause the control system to attain a new state and consequently a new set of output logical variables will be generated. This combination of output signals will cause the boring spindle to start moving forward in a rapid phase motion (uncontrolled motion). At the same time the spindle motor will be switched on and start rotating. However, since the spindle motor has not yet reached the feeding position, this rotation speed will remain unaffected by the servo motor control algorithm. Simulation for the angular velocity of the spindle motor is shown in Figure 8.

It is shown from Figure 8 that the spindle motor will attain a constant rotation speed of 3173 rpm. after a transient period of about 5 seconds. The spindle motor was simulated assuming zero load torque on the spindle that is because the boring spindle has not yet reached feeding position. The objective of the control system will be to keep spindle motor within 3000 r.p.m. under all loading conditions. Simulation of the linear speed and the differential pressure of the hydraulic actuator is shown in Figure 9. I t shows that the rapid phase velocity of the actuator is about 6cm/sec.

The system will continue to operate within the boundaries shown in Figure 8 and Figure 9 until i t receives a new set of input sources. That set will be initiated when the boring spindle reaches position M.

Due to the signals generated from the interface with physical system, which is no longer at rest, combined with a new set of signals from the micro breakers. The control system will attain a new state and generate another set of output signals to be interpreted by the mapping function and converted into new input physical signals. In this case, the boring spindle will go from rapid phase motion (6cmkec) to a controlled feed forward motion in such way that the feed forward motion will be kept at 2cm/sec, and the rotating speed of the spindle motor should be reduced from 3173 r.p.m. to be within 3000 r.p.m. under all loading conditions. The actuator linear velocity will be controlled by the servo valve controller algorithm. And the boring spindle motor will be controlled by the servo motor controller algorithm. Assuming that the servomotor is subjected to cosine load torque given by ( q = 2 x cost ) and the hydraulic cylinder is subjected to load force given by ( F ~ = 0.0s x c o s t ) . Simulation results are shown in Figure 10 and Figure 1 1.

The simulation shows that the output speed of both the spindle motor and the actuator cylinder are kept within the boundaries specified by control algorithm.