Keqin Ding

Publication Date


Document Type

Honors Project

Degree Name

Bachelor of Science




Susannah V. Howe


Control systems, Arduino, Proportional-integral-derivative control theory, Bang-bang controller, pH control, PID controllers-Design and construction, PID controllers-Testing, Arduino (Programmable controller), Hydrogen-ion concentration-Measurement


Automation is a pervasive aspect in the pharmaceutical industries, as it proposes less operator interaction and more systematic control. To achieve automation in various industrial settings, feedback control is commonly used for recording measurements and controlling responses. This report details the project on conducting a proof of concept to investigate whether using proportional-integral-derivative (PID) control theory with Arduino as the microcontroller platform was a feasible approach to automate pH control, as pH neutralization is common in pharmaceutical manufacturing. The first stage of the project was a literature review on proportional-integral-derivative (PID) control theory and its common industrial applications, followed by exploration of programming an Arduino chip, which was the controller platform used. The second stage was a series of Arduino program development and testing with known input signals, to evaluate different modes of output control. An integrated design was then developed that combined the Arduino program as the controller, a pH meter and a printed circuit board as the sensor, a servo motor and an LED as the controlled output indicators. Analysis of my design indicated that it implemented the theory behind bang-bang control, but also showed its limit on delayed output. Future development listed three different aspects: pH sensor refinement, Arduino program development to realize PID control, customized printed circuit board refinement, and control system models. Ultimately, this proof of concept can be developed to implement in various pharmaceutical manufacturing lines where control automation is in need.


2018 Keqin Ding. Access limited to the Smith College community and other researchers while on campus. Smith College community members also may access from off-campus using a Smith College log-in. Other off-campus researchers may request a copy through Interlibrary Loan for personal use.




[v], 45 pages : color illustrations. Includes bibliographical references (pages 22-23)