IC 8451&CONTROL SYSTEMS
Department of Electrical and Electronics Engineering
Approved by AICTE | Affiliated to Anna University | Accredited by NAAC | Accredited NBA | Recognized by UGC under 2(f) and 12(B)
Chennai Main Road, Kumbakonam- 612 501.
ARASU ENGINEERING COLLEGE
1
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
2
Prepared by
Mrs.K.Kalpana.,M.E.,(Ph.D).,
Department of Electrical and Electronics
Engineering
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
3
 Electrical Analogous of mechanical translational systems
 There are two types of electrical analogies of translational mechanical
systems. Those are force voltage analogy and force current analogy.
 Force Voltage Analogy
 In force voltage analogy, the mathematical equations of translational
mechanical system are compared with mesh equations of the electrical
system.
Translational Mechanical System Electrical System
Force(F) Voltage(V)
Mass(M) Inductance(L)
Frictional Coefficient(B) Resistance(R)
Spring Constant(K) Reciprocal of Capacitance
(1/c)
Displacement(x) Charge(q)
Velocity(v) Current(i)
 Force Current Analogy
 In force current analogy, the mathematical equations of the
translational mechanical system are compared with the nodal
equations of the electrical system.
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
4
Translational Mechanical System Electrical System
Force(F) Current(i)
Mass(M) Capacitance(C)
Frictional coefficient(B) Reciprocal of Resistance(1/R)
Spring constant(K) Reciprocal of Inductance(1/L)
Displacement(x) Magnetic Flux(ψ)
Velocity(v) Voltage(V)
 Analogous elements in Force voltage analogy
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
5
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
6
Analogous elements in Force current analogy
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
7
 EXAMPLE PROBLEM 1
 Write the differential equations governing the mechanical system shown in
fig. Draw the force voltage and force current electrical analogous circuits and
verify by writing mesh and node equations.
 The free body diagram of M1 is shown in fig. The opposing forces are
fm1,fb1,fb12,fk1
 The free body diagram of M1 is shown in fig. The opposing
forces are fm2,fb2,fb12,fk1 and fk2
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
8
 Force voltage analogous circuit
 The electrical analogous elements for the elements of mechanical
systems are
f(t) - e(t) , M1- L1, M2- L2, B1- R1, B2- R2 ,B12- R12, K1-1/C1, K2-1/C2
 The mesh equations are
 Force -voltage analogous circuit
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
9
 Force current analogous circuit
 The electrical analogous elements for the elements of
mechanical systems are
f(t) - i(t) , M1- C1, M2 -C2, B1-1/R1, B2-1/R2 ,B12-1/R12, K1-1/L1,
K2-1/L2
The node equations are
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
10
 Force current analogous circuit
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
11
 EXAMPLE PROBLEM 2
 Write the differential equations governing the mechanical
system shown in fig. Draw the force voltage and force current
electrical analogous circuits and verify by writing mesh and
node equations.
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
12
 The free body diagram of M1 is shown in fig. The opposing
forces are marked as fm1, fb1, and fk1, fk2
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
13
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
14
Free body diagram of M2 is shown in fig. The opposing forces are marked as
fm2 , fb3, fk2 & fk3.
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
15
The free body diagram of M3 is shown in fig. The opposing forces are marked as
fm3, f b3 and fk3
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
16
FORCE VOLTAGE ANALOGOUS CIRCUIT
MESH EQUATIONS
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
17
FORCE VOLTAGE ANALOGOUS CIRCUIT
FORCE CURRENT ANALOGOUS CIRCUIT
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
18
NODE EQUATIONS
FORCE CURRENT ANALOGOUS CIRCUIT
ARASU
ENGINEERING
COLLEGE
IC 8451&CONTROL SYSTEMS
19
HOME WORK PROBLEM
Write differential equations governing mechanical system shown in fig. Draw
force voltage and force current electrical analogous circuits and verify by writing
mesh and node equations.

Electrical analogous of mechanical translational system

  • 1.
    IC 8451&CONTROL SYSTEMS Departmentof Electrical and Electronics Engineering Approved by AICTE | Affiliated to Anna University | Accredited by NAAC | Accredited NBA | Recognized by UGC under 2(f) and 12(B) Chennai Main Road, Kumbakonam- 612 501. ARASU ENGINEERING COLLEGE 1
  • 2.
    ARASU ENGINEERING COLLEGE IC 8451&CONTROL SYSTEMS 2 Preparedby Mrs.K.Kalpana.,M.E.,(Ph.D)., Department of Electrical and Electronics Engineering
  • 3.
    ARASU ENGINEERING COLLEGE IC 8451&CONTROL SYSTEMS 3 Electrical Analogous of mechanical translational systems  There are two types of electrical analogies of translational mechanical systems. Those are force voltage analogy and force current analogy.  Force Voltage Analogy  In force voltage analogy, the mathematical equations of translational mechanical system are compared with mesh equations of the electrical system. Translational Mechanical System Electrical System Force(F) Voltage(V) Mass(M) Inductance(L) Frictional Coefficient(B) Resistance(R) Spring Constant(K) Reciprocal of Capacitance (1/c) Displacement(x) Charge(q) Velocity(v) Current(i)
  • 4.
     Force CurrentAnalogy  In force current analogy, the mathematical equations of the translational mechanical system are compared with the nodal equations of the electrical system. ARASU ENGINEERING COLLEGE IC 8451&CONTROL SYSTEMS 4 Translational Mechanical System Electrical System Force(F) Current(i) Mass(M) Capacitance(C) Frictional coefficient(B) Reciprocal of Resistance(1/R) Spring constant(K) Reciprocal of Inductance(1/L) Displacement(x) Magnetic Flux(ψ) Velocity(v) Voltage(V)
  • 5.
     Analogous elementsin Force voltage analogy ARASU ENGINEERING COLLEGE IC 8451&CONTROL SYSTEMS 5
  • 6.
  • 7.
    ARASU ENGINEERING COLLEGE IC 8451&CONTROL SYSTEMS 7 EXAMPLE PROBLEM 1  Write the differential equations governing the mechanical system shown in fig. Draw the force voltage and force current electrical analogous circuits and verify by writing mesh and node equations.  The free body diagram of M1 is shown in fig. The opposing forces are fm1,fb1,fb12,fk1
  • 8.
     The freebody diagram of M1 is shown in fig. The opposing forces are fm2,fb2,fb12,fk1 and fk2 ARASU ENGINEERING COLLEGE IC 8451&CONTROL SYSTEMS 8
  • 9.
     Force voltageanalogous circuit  The electrical analogous elements for the elements of mechanical systems are f(t) - e(t) , M1- L1, M2- L2, B1- R1, B2- R2 ,B12- R12, K1-1/C1, K2-1/C2  The mesh equations are  Force -voltage analogous circuit ARASU ENGINEERING COLLEGE IC 8451&CONTROL SYSTEMS 9
  • 10.
     Force currentanalogous circuit  The electrical analogous elements for the elements of mechanical systems are f(t) - i(t) , M1- C1, M2 -C2, B1-1/R1, B2-1/R2 ,B12-1/R12, K1-1/L1, K2-1/L2 The node equations are ARASU ENGINEERING COLLEGE IC 8451&CONTROL SYSTEMS 10
  • 11.
     Force currentanalogous circuit ARASU ENGINEERING COLLEGE IC 8451&CONTROL SYSTEMS 11
  • 12.
     EXAMPLE PROBLEM2  Write the differential equations governing the mechanical system shown in fig. Draw the force voltage and force current electrical analogous circuits and verify by writing mesh and node equations. ARASU ENGINEERING COLLEGE IC 8451&CONTROL SYSTEMS 12
  • 13.
     The freebody diagram of M1 is shown in fig. The opposing forces are marked as fm1, fb1, and fk1, fk2 ARASU ENGINEERING COLLEGE IC 8451&CONTROL SYSTEMS 13
  • 14.
    ARASU ENGINEERING COLLEGE IC 8451&CONTROL SYSTEMS 14 Freebody diagram of M2 is shown in fig. The opposing forces are marked as fm2 , fb3, fk2 & fk3.
  • 15.
    ARASU ENGINEERING COLLEGE IC 8451&CONTROL SYSTEMS 15 Thefree body diagram of M3 is shown in fig. The opposing forces are marked as fm3, f b3 and fk3
  • 16.
    ARASU ENGINEERING COLLEGE IC 8451&CONTROL SYSTEMS 16 FORCEVOLTAGE ANALOGOUS CIRCUIT MESH EQUATIONS
  • 17.
    ARASU ENGINEERING COLLEGE IC 8451&CONTROL SYSTEMS 17 FORCEVOLTAGE ANALOGOUS CIRCUIT FORCE CURRENT ANALOGOUS CIRCUIT
  • 18.
    ARASU ENGINEERING COLLEGE IC 8451&CONTROL SYSTEMS 18 NODEEQUATIONS FORCE CURRENT ANALOGOUS CIRCUIT
  • 19.
    ARASU ENGINEERING COLLEGE IC 8451&CONTROL SYSTEMS 19 HOMEWORK PROBLEM Write differential equations governing mechanical system shown in fig. Draw force voltage and force current electrical analogous circuits and verify by writing mesh and node equations.