Position control system block diagram
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The document describes the components and block diagram of a position control mechanism. It contains: 1) A DC motor that drives a load through a gearing to amplify torque. The load position is sensed by a potentiometer and compared to a reference input from an identical potentiometer to determine position error. 2) This error signal is fed to an amplifier to control the motor armature voltage. The effective inertia and friction at the motor shaft is calculated. 3) A block diagram shows the relationship between motor speed, armature voltage, and other components in the closed loop position control system.
Position control system block diagram
- 1. GOVERNMENT ENGG. COLLEGE, DAHOD CONTROL ENGINEERING BLOCKDIAGRAM OF POSITION CONTROL MECHANISM
- 2. Introduction : • The word servo means controlling mechanical position or derivatives of position like velocity and acceleration. • It is an automatic device that uses the error sensing negative feedback to correction of performance of mechanism. • Servo control mechanism uses negative feedback which is used to control the mechanical position. • Position control servo mechanism used in hydraulic and pneumatic machines to control the position. • It is also used in automatic machine tools, satellite tracking antenna, Air craft system and navigation system.
- 3. Fig. Position controlled servo mechanism.
- 4. Various Components of the system : • Drive motor dc armature controlled. • Load is driven through a reduction gearing to amplify torque for moving load. • Load angular position is sensed by circular potentiometer. • Angle reference input sensed by an identical potentiometer. • Position error is fed to amplifier to feed the motor armature at voltage Ea.
- 5. • For control system load reflected to motor shaft is giving the effective inertia and friction at motor shaft as, J = JM + n2 JL f = fM + n2 fL • To begin with block diargam of linking wM motor speed, armature voltage ea . It is given in figure of block diagram.
- 6. • Reducing block diagram,
- 7. Various Components of the system : • Drive motor dc armature controlled. • Load is driven through a reduction gearing to amplify torque for moving load. • Load angular position is sensed by circular potentiometer. • Angle reference input sensed by an identical potentiometer. • Position error is fed to amplifier to feed the motor armature at voltage Ea.
- 8. Complete Block diagram: • Effective motor time constant including friction f and equivalent friction effect cause by motor back emf (Kb KT)/Ra. • Symbol r is reversed for motor’s mechanical time constant t = J/f.
- 9. Forward path transfer function :