Custom Air Pressure & Flow Rate Control System

Generating stable, controllable air flow for experimental purposes

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For colleagues from the sound project, please go to this page: Air Supply System Manual, for details on how to operate the control system.

Overview

The inherent characteristics of air, such as its compressibility and susceptibility to environmental factors like temperature, pressure, and humidity, make controlling the flow rate and pressure in a flow system complicated.

The Berkeley Embodied Dexterity Group's ongoing project, Pneumatic-driven Vibration, explores how the physical shape of an apparatus interacting with flowing air can produce different sound pitches. However, the researchers previously faced limitations due to imprecise manual measurements using analog devices like pressure gauges and flow meters.

To address this issue, I proposed and designed a system that provides more accurate digital measurements and self-regulates based on feedback, including pressure, flow rate, and eventually sound frequency.

Stage 1: Constructing a working system ✅

Mechanical

The main components of the mechanical system consist of the following:

• Linear valve (proportionally control the flow rate, 1/8" FPT)

• Pressure regulator (control the pressure, 1/8" FPT)

• Flow sensor (measure the total flow rate, 3/8" quick connect, 1/2" NPT for the back up version)

• Pressure transducer (report the back pressure, 1/8" NPT)

To ensure the system is portable while maximizing compatibility with the existing lab set-up, I designed the air supply to be able to interface with the lab air source (unregulated), or an air compressor with a 6-gallon tank. The lab source provides a 3/8" quick connect port, while the the compressor's NPT port is 1/4".

Electrical

Electrical System

Electrical components

Intergated electromechanical system (isometric view)

Intergated electromechanical system (top view)

For detailed information about the electrical system and its components, please visit Air Supply System Manual

Software

I chose Arduino for this development for its advantage in creating simple control systems, as our goal is to zero in on the desired pressure and flow rate. A small program was created to make sure the system could boot up properly.

Air-Supply/sketch_jun10a/sketch_jun10a.ino at main · yuxinliuhubert/Air-SupplyGitHub

A simple Arduino file that will become the calibration and testing program

Stage 2: Calibrating and testing

New Arduino files and Matlab files will be created to calibrate the pressure transducer and flow sensor. The process will be similar to Automated Instrument Calibration documented in STAR Liquid Engine Project.

Stage 3: Feedback based on frequencies

When the calibration and testing work is done, we plan to use the sound frequencies emitted by the apparatus to adjust the air supply valves. Researchers can input a desired frequency, and the machine will adjust accordingly.

Personally, I would love to see the air supply holding a concert in the future.