DESIGN
PROJECT
BIOEN
3023
SPRING
2005
Problem Statement
|
System
Schematic |
A system to provide variable flows of a heating medium
(water) for a tissue culture system is needed as a part of a design study for a
company working in bio-technology. The
system will form part of a tissue-culture workstation. The completed system should be able to
dispense variable flowrates of media at a temperature
of 78 oC + 1 oC.
Target flowrates will vary between 5 ml/min
and 25 ml/min. The figure shows a
diagram of the system.
Approach
A
one-month period has been planned to allow you to focus on completion of the
design project as a part of this course.
The project is an opportunity for you to apply principles and tools you
have studied during the first part of the course. You have the opportunity to develop and apply
your choice of approach and solution to the problem.
You will need to address the
design approach, as well as implementation and testing phases of the
project. The processes and justification
for the design decisions that you make should be well documented during the
process. You should keep a written
journal of the work done during the project.
All work and calculations that you do on the project should be recorded
in the journal. Scratch paper should not
be necessary, you can use the journal (Even if you are
not perfectly neat all the time!). You
should have your colleagues review your journal regularly during the project and confirm that they have witnessed
the work that you have done by signing and dating the bottom of each page. This is a common practice in industry, and
allows innovations that you develop during your work to be conveniently
patented. The journal and final report
must be your independent work. Data and
results you have collected should be used in the report, as well as discussion,
computation of ITAE for your system, and conclusions. The report should convince me to adopt the
design solution proposed. Convincing
documentation and discussion should be provided, and well justified conclusions
drawn.
Three
hardware systems are available for your use in implementing your controller:
1. Yokogawa UT14 digital indicating
controller. This unit is a
microprocessor based Digital Indicating PID controller with advanced features.
2. Analogic Acro-400E digital data acquisition and control
system with a Menu oriented control software package, as well as built in
control-BASIC.
3. A
PLC (programmable logic controller) based controller.
You may
incorporate additional components with my approval.
Manuals for the Yokogawa, Acro, and PLC systems are available. In addition, a complete laboratory report
done in a previous year, outlining tuning information is available. A sample program written in Acro control-BASIC is attached for your reference. PC
compatible micro-computers are available at the Agricultural Engineering
Laboratory for your use in evaluation of the Acro
unit. If you choose to use this unit a
PC will be made available with the Acro.
Complete
packages of the supply reservoir, heating exchanger tank, heater, and
thermocouple or thermistor will be provided to each
team. These packages are available at
the Agricultural Engineering Laboratory in room 108. Size constraints for the product you are
developing prevent making any of the components larger. Arrangement of components or other changes in
the design that do not add costly components or increase the size of the system
are up to your team. Please consult with
me before proceeding with development using a system configuration that is
significantly different from that diagrammed above.
Performance Evaluation
The
performance of the system that is developed will of course play
an important role in evaluation of your work.
The major component used in grading will be based on timely submission
of a convincing, well documented report describing the design process, testing,
and final performance test of the system.
System performance will comprise 10% of your project grade based on the
performance of your system compared to your peers. I will assist you in measuring performance at
your request at the end of the project.
I will provide your system with a disturbance, and measure temperature
of the output stream. You must calculate
ITAE based on that temperature. 5% of
your grade will be based on your systems ability to maintain within 5% of the
set point temperature within 5 minutes of a significant disturbance (to be
provided by me). The remaining 95% of
your grade will be based on my evaluation of your report. I will look for the following items in your
report and assign points for each item:
1. Convincing
case for selection of a particular controller and system configuration, and
rejection of other alternatives.
2. Evidence
of a logical strategic plan and execution of the plan in your work.
3. A
neat and professionally done report.
4. An
attached complete journal of your work.
5. Documentation
and correct computation of the ITAE performance test of your system.
Schedule
The
Final report on the project should be submitted to me on or before the final
exam for this class.
SAMPLE PROGRAM FOR THE ACRO 400
5 TIME$="
10 RANGE(9)
= 1 :REM Set range for thermocouple to one
volt
20 DOUT(1) = 0
:REM Turn off heater
30 REM All variables are
global I have used S,M,H,R,V,T,J & P
40 REM S is seconds
since start of program
50 REM T is temperature
in Degrees Celsius
60 REM P is the
percentage of time the heater is to be on 100 = 100%
70 REM The other variables are use internal to various routines
100 REM ========== Your
Program ==================================
110 GOSUB 1000 :REM Execute Time Routine
120 PRINT S, M, H :REM Display time
statistics
130 GOSUB 2000 :REM Get Temperature
140 PRINT T :REM Display
Temperature
150 P=25 :REM Set heater duty cycle to 25%
160 GOSUB 3000 :REM Energize heater for one cycle
170 GOTO 110 :REM Repeat forever
999 END
1000 REM =========
Get Time in seconds ==============================
1005 S = VAL(TIME$(7,8)) :REM Calculate
number of seconds since start
1010 M = VAL(TIME$(4,5))
1020 H = VAL(TIME$)
1030 S = S + 60 * M + 360 *H
1040 RETURN
2000 REM
========= Get Temperature in Celsius =========================
2100 R = CJR :REM reference temp
2110 V = VIN(9) :REM get tc
voltage
2120 T =
TEMP("T",V,R) :REM convert to oC, "T" = ThermocoupleType
2120 RETURN
3000 REM
========= Energize heater for P % of a cycle=====================
3005 REM The
variable P sets the percent of time the heater is ON
3006 REM 0 =
OFF, 50 = ON 50% time, 100 = ON 100% time
3010 FOR j = 1 TO 100 :REM takes about
1 second
3020 IF J<P THEN DOUT(1)
= 1 ELSE DOUT(1) = 0
3030 NEXT J
3040 DOUT(1)
= 0 :REM Turn off heater
3050 RETURN