ELE442 – Control Systems
Final Project – Fall 2023
Instructor: Dr. Noel J. Maalouf
Due date: Thursday December 14, 2023 at 11:55pm
Guidelines
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The Final Project will be divided into 3 parts: Needs Assessment, Analysis of the System, and
Design & Tuning of the Controller. You will submit the 3 parts together on the due date.
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Your Final Project Report should be complete, include everything that you deem necessary
(Introduction, References, plots, Root Locus, frequency plots, graphs, screenshots,
appendices,…). At the same time, you should be clear and concise.
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The audience of your report is the engineering manager.
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Use technical style: aim for clarity, conciseness, and precision in language and presentation.
Use formatting, such as spacing and subheadings, to support the clarity of presentation. All
figures and tables must include captions. Figures and tables must also be acknowledged and
discussed within the text itself.
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Follow IEEE documentation guidelines. Use Times New Roman, 12 pt., single space.
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Any program or code used should be submitted on the dedicated portal.
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You are required to abide by the page limit for each part. Extra pages will result in deduction
of grades.
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Every team will submit one report stating clearly on the title page the names and ID numbers
of each team member.
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Every team should upload on BlackBoard a final report and an m file both named as
such ‘LastName1_LastName2’, showing the last names of all group members. The m file
should include all the code used in this project with comments. It should draw the closedloop step response of your uncompensated system and on the same figure the closed-loop
step response of the compensated system.
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There will be two portals on BlackBoard, one for the report and another for the code file.
The report must be submitted either in Microsoft Word or pdf format. No zipped folders
are allowed.
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All submitted files will be subject to a plagiarism check. Any case of plagiarism will result
in a grade of zero for all involved parties.
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Project Objective
The aim of this project is for you to design a control system that satisfies exact specifications. In
the scenario presented, you are a team of engineers working for the manufacturer that needs a
controller. At the end of the design project, you will compose a technical report addressed to the
engineering manager.
The project consists of three parts. In part 1 you are required to go over the project description and
extract the requirements in addition to the technical and non-technical constraints. You are also
required to conduct a literature and product review. In part 2 you are required to analyze the
uncompensated system. Part 3 consists of the analysis, design, and evaluation of the controller.
Note that the control model and specifications as provided are for academic purposes and do not
correspond accurately to the actual practical models.
Customer Description
“RobSolutions” provides robotic solutions to industrial customers. They are leaders in automated
robotic arms and grippers in the MENA region. One of their customers is an agricultural company that
sells tomatoes. They requested a gripper that picks tomatoes from orchards and exerts the appropriate
force without damaging the fruit. Due to regulations set by the Union of Greengrocers, there are
standards set for greengrocers to avoid damage and degraded quality. For this reason, field testing was
conducted, and the engineers at RobSolutions found that the primary condition is the gripper force,
which must be maintained at 10 ± 0.01𝑁 to avoid damaging the fruit and slippage. They also
concluded that the contact force must not exceed 11𝑁 to avoid ruining the tomato and damaging the
gripper. Moreover, the agricultural company’s managers specified that the duration of completing the
grasp of the tomato must not exceed 1.5s to allow efficient picking (assume initial force value to be
0 𝑁). For this project, RobSolutions require their top control engineers (YOU) to design and analyze
within 4 weeks a force controller for the tomato gripper at a cost less than 700 USD. Since the process
of tomato picking is outdoors by nature, the controller packaging must protect from injection of water
from a nozzle and must not allow dust (use IP codes for this requirement).
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Part 1 – Needs assessment and system modeling
Needs Assessment: First, you are required to carefully go over the customer project description
and extract the requirements, specifications and technical/non-technical constraints.
System Modeling: Indicate how you might model the plant in order to use it in the design and
analysis phase. You are not required to come up with the model but just indicate the
methods/approaches that can be used to obtain a model of the plant.
Literature and Product Review: You are required to review the literature related to tomato
picking grippers and to survey products which can be used as force controllers (for example
check omega.com). Your review must include references to research papers and actual force
controllers available in the market. In your review of research papers, you must include a summary
and an analysis of the methods described. Pneumatic force controllers and other types of force
controllers are accepted. Clearly some might be too advanced to fully understand and that is fine.
For the products, you must include a description of their features anda brief analysis of whether
they can be used in your project.
N.B.: Part 1 must include a brief introduction, a section for the needs assessment (not to exceed
one page), and a section for the literature and product review, with a list of references (not to
exceed two pages).
Part 2 - Evaluation of the uncompensated system 𝑮(𝒔)
The differential equation governing the dynamics of the force control of the gripper was
obtained using one of the techniques you described in Part 1:
𝑑 2 𝑌(𝑡)
𝑑𝑌(𝑡)
5
+ 0.1
= 500𝑅(𝑡)
2
𝑑𝑡
𝑑𝑡
where 𝑦(𝑡) is the force exerted and 𝑟(𝑡) is the pressure input to the gripper.
In this part, you are required to evaluate the original uncompensated system 𝐺𝑃(𝑠) in a closedloop unity feedback configuration (Fig. 1). Given the compensator 𝐺𝐶(𝑠) = 1, perform the
following simulations in MATLAB with the closed-loop system.
Figure 1: Closed-Loop Unity Feedback System
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a. The closed-loop step response from reference input to output, plotting the output signal 𝑦(𝑡)
vs. 𝑡.
b. The closed-loop ramp response from reference input to output, plotting the output signal 𝑦(𝑡)
vs. 𝑡.
c. The variation of the control input 𝑢(𝑡) vs. 𝑡.
d. Plot the Root Locus of the uncompensated system.
Analysis: Discuss the uncompensated responses in terms of the final value, overshoot, settling
time, and steady-state error in the step response at the output (𝑡), and the steady-state error in the
ramp response.
Discuss the relationship between the final value of the control signal 𝑢(𝑡) and the output 𝑦(𝑡) in
terms of the transfer function 𝐺𝑃(𝑠).
N.B.: Part 2 must not exceed three pages.
Part 3 - Design of a compensator 𝑮(𝒔)
This section involves the design of a compensator 𝐺(𝑠) that makes the system satisfy the
specifications and technical constraints set by the customer.
a. First you have to list 3 types of compensators with brief description of how they work.
b. You are required to design and analyze 2 different compensators (refer to the compensator
types we covered in class).
c. After comparing both alternatives, you have to choose the one that best fits with the customer
specifications and technical constraints. Once the final design is chosen, you have to write the
overall transfer function of the final system and also show the steps you followed to finetune the compensator.
d. The evaluation of your final system design should include time domain and frequency
domain analysis techniques.
e. Analyze the variation of the control input 𝑢(𝑡) vs. 𝑡 and its effect on the choice of the
controller. Comment on the feasibility of meeting all required specifications.
N.B.: Part 3 must not exceed four pages.
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Bonus Part
The customer asked about the possibility of sorting the tomatoes into two classes: (a) firm tomatoes
that are suitable to be consumed fresh and (b) soft tomatoes that are suitable for making pastes and
salsas. To achieve this goal, RobSolutions suggest that a sample tomato is taken from each batch and
the gripper applies a varying force on the tomato to sense how firm it is and sort it accordingly.
a. Identify the type of reference input which is suitable for this firmness test.
b. Simulate the controller you chose in Part 3 for the identified input and evaluate the system’s
response.
c. Apply any necessary changes to the controller design to improve the system’s performance.
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