First Advisor

Alexander Hunt

Term of Graduation

Summer 2023

Date of Publication


Document Type


Degree Name

Master of Science (M.S.) in Mechanical Engineering


Mechanical and Materials Engineering




artificial muscle, BPA, Length Sensing, McKibben muscle, pneumatic muscle, VL53L0X



Physical Description

1 online resource (vii, 54 pages)


Braided Pneumatic Actuators (BPAs) are used widely in robotics as artificial muscles because of their similar characteristics to biological muscles. When a BPA is pressurized, it expands in the radial direction and contracts in the longitudinal direction. The contraction generates a pulling force that is dependent on the input pressure and BPA length. Biological muscle also behaves in the same way where a pulling force is generated on a contraction. To control BPAs on a robot, the real-time pressure and length measurements are necessary. In this dissertation, I present a new method to measure length of BPAs in real-time using a time-of-flight IR sensor. The IR sensor VL53L0X is integrated inside an air-tight housing so that it can be mounted to one end of a BPA during pressurization. The sensor uses I2C communication protocol, hence only two wires are needed to be connected to the bus line for communication with a microcontroller. Additionally, more sensors can be added to a bus without significantly impacting the sampling delay performance. The proposed Time-of-Flight sensor has an average of 8.5% Root Mean Square Percentage Error, and the sampling frequency is up to 50Hz.


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