8/3/2019 Module 7 MCR
2/3
Interpretation of Data
Module no.7 entitled On-Off, P, PI, and PID controller
Simulations using Simulink coversthe different types of controllers
through computer simulations.
First part was to analyze the On-Off controller system. Using
Matlab Simulink, figure 7.2
was established. To analyze the system, step response, steady
state error and the output wasobtained. Interpreting the results,
the On-Off controller can be best described using its stepresponse
as observed. In this response it has two discrete values HI and LOW
meaning that ithas two trigger points that when triggered will
either go HI or LOW or simply On and Off. Asbeen analyzed, this is
how the on-off controller works. It has two trigger points that
whentriggered, the process will execute or the process will be
interrupted.
Second part was using proportional controller, P established at
figure 7.3. In this type ofcontroller, proportional gain is
involved as seen in the figure. As with the responses, stepresponse
shows a sudden increase reaching a peak of 1 and then decreasing
with a parabolicpath with observed oscillations upon reaching its
steady state. This response was also foundsimilar
with the error response. It control output shows a direct
parabolic increase and oscillationsupon reaching steady state. The
proportional gain applied to the system as observed wasresponsible
for its response. This gain sets the response of the system in
proportion to the otherparameters of the system. Increasing the
gain of the system also increases the percentovershoot of the
system which in return decreases the error of the system. This is a
goodresponse since the overshoot is large therefore the error is
small enough to call the systemstable in its steady state.
Proportional Integral Controller was examined in third part of
the module. More complexsystem is involved in this controller as
seen on figure 7.4 which involves the integral gain as wellas a
transfer function. Something common among the responses were
observed which is the
oscillations upon reaching the steady state. As the integral
gain is increased, settling time alsoincreases. This settling time
is the time it takes for the system to experience the steady
state.The lesser time, the better response of the system and it was
observed at integral gain of 0.5which yields the least time.
PID, Proportional Integral Derivative controller was the last to
be analyzed. Morecomplex than the PI controller due to the presence
of another component on the system whichis the derivative block as
seen on figure 7.5. As observed, its step response has an
overshootthat is very large with only one peak. Sudden increase and
oscillations were also observed onthe error response as well as the
output. As the gain increases varied output were observed butwhat
matters the most is the settling time which has to be the fastest
to be considered the bestresponse among them. In this case at gain
equal to 5 is the best due to its fastest settling time
to reach steady state.
8/3/2019 Module 7 MCR
3/3
Conclusion
Different types of controller as analyzed from this experiment
came to realizations andobservations that is necessary for the
analysis of any system. These are the most of thegathered
observations and conclusions obtained from the experiment.
On-Off controller works on discrete response which is HI and
LOW, 1 and 0. Thissignifies the trigger point of the system. Once
it is triggered it will either go ON orOFF
. Proportional controller basically works on proportionality
among the system. This
system works proportional to the error of the system and this is
set by theproportional gain of the system. The gain with the
smallest error yields the bestresponse.
Proportional Integral Controller is a proportional controller
with a bit of innovationwhich is the addition of the integral gain.
This integral gain compensate for theinabilities of the
proportional controller itself. With the integral property of the
PI
controller, the system will cover more application. The integral
gain with fastestsettling time would definitely yield the best
response.
Proportional Integral Derivative Controller works better than
the prior controllersconsidering its wide application compared to
others discussed. With thederivative action of the controller,
inabilities of other controllers are compensatedwith the derivative
action. In this system, the gain that will yield the
fastestsettling time will be considered the best response. In this
response the derivateaction was considered which makes the system
better than the others.
