Till 15 Nov - Include 5th Asgn Part

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Performance is judge by two parameters Transient Performance

Steady State Performance Example

Automobile ----- Driver Pushes pedal for increasing the speed

Time history will be the transient response

High performance car designed more responsive than car usedfor transportation

Steady state is achieved on reaching desired velocity

Steady state depends upon Aerodynamics of the car

Road

Wind conditions Efficiency of the engine ,etc


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This chapter deals with

Analyzing the tendency of closed loop system to

follow the desired command Steady state performance of a system in relation

to a system follow a desired command

Commands can be a power of time and most

commands can be approximated by the sum of a

step , ramp and so forth


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Example---- driver of automobile acts as aguidance system Observe environmental conditions and

destination Issue command by depressing the pedal

and by steering the wheels


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Example---- Missile has a electronic guidance

system to monitor the target motion Compute corrective commands So missile will intercept the target(MATLAB PART )


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Input or command ------ r(t) Control System should quickly response to the commands A very responsive control system: the guidance command

should appear to be fairly slow varying function of time Command can be approx by the sum of the step ramp and

so on

r(t) can be expressed as power series like


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Tracking System A tracking system is a controlsystem that creates an output that tracks

(follows) the input to some level of tolerance Tracking Responses to several reference inputs


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Example ( Elevation Control system of Dish Antenna)


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Qualities of a Good Tracking System Natural Response Decay rapidly Without excessive fluctuations Leaving forced components of the response Analysis and design of tracking system be

separated in two parts Poles location of the transfer function Tracking of the reference input by the

forced response of the system Regulator System

Which intend to maintain the output of thesystem as some desired constant level


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Relative Stability The relative stability of asystem is the distance into the left half of thecomplex plane from imaginary axis to thenearest characteristics root or roots


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Low damping ratio / less damping angle is desiredfor tracking

Requirement for the damping ration and relative

stability are combined can be given as


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StefaniDrill Problem C 3.1, D3.1(b,d), -----(page No 188)Problems 1(c), 2, 3 (c,d), ----- (page No 244)

Part of Assignment Five

Submitted on 26 Nov 12


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Steady State Error

Poles of TE(s) and T(s) will be the same Error signal generally composed of natural and

forced part


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Initial Value Theorem


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Final Value Theorem


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Final Value Theorem

Case I

Case II

Case III


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Steady State Error to Power- Off -TimeInputs


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Steady State Error to Power- Off -TimeInputs

Example


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Steady State Error to Power- Off -Time Inputs( Three possible steady state behaviour)


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Reproduce three examples given on page 194 (system

has zero steady state step error and steady stateramp and parabolic input )



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StefaniDrill Problem C 3.2, D3.2(b,d), D3.3( c,d), 3.4(a,c) ---(page195)Problems 3(c), 4(d), 5(b), ----- (page No 246)



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Power Off Time Error Performance--- ( SystemType Number)

Step input


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Power Off Time Error Performance-( SystemType Number) Ramp input

Due to repeated roots final value theoremdoes not apply


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Power Off Time Error Performance-( SystemType Number) Stable system

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