Page 326 - Mechanical Engineers' Handbook (Volume 2)
P. 326

4 Standard Forms for Linear Models  317










































                                                                                    3
                            Figure 9 An idealized model of a milling machine: (a) lumped-element model, (b) system graph.


                                                      1
                                                  	     v    and   T   Rƒ  r
                                                   2
                                                                    p
                                                      R
                           there are now five equations in the five unknowns 	 , 	 , v, T , and ƒ . Combining these
                                                                             p
                                                                                    r
                                                                     1
                                                                        2
                           equations to eliminate all of the unknowns except v yields, after some manipulation,
                                                   3
                                                           2
                                                  d v     d v    dv
                                                a      a       a      a v   bT
                                                 3  3   2  2    1      0    1
                                                  dt      dt      dt
                           where
                                                           JK                   K
                                            a   Jm     a        Bb   mK    b
                                                                            1
                                                        1
                                             3
                                                           R  2                 R
                                                                     BK
                                                 a   Jb   mB     a        Kb
                                                  2
                                                                  0
                                                                     R  2
                           Differentiating yields the desired I/O equation
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