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.