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- Member of: Barrett, The Honors College Thesis/Creative Project Collection
- Resource Type: Text
Oscillatory perturbations with varying amplitudes and frequencies have been found to significantly affect human standing balance. However, previous studies have only applied perturbation in either the anterior-posterior (AP) or the medio-lateral (ML) directions. Little is currently known about the impacts of 2D oscillatory perturbations on postural stability, which are more commonly seen in daily life (i.e., while traveling on trains, ships, etc.). This study investigated the effects of applying 2D perturbations vs 1D perturbations on standing stability, and how increasing the frequency and amplitude of perturbation impacts postural stability. A dual-axis robotic platform was utilized to simulate various oscillatory perturbations and evaluate standing postural stability. Fifteen young healthy subjects were recruited to perform quiet stance on the platform. Impacts of perturbation direction (i.e., 1D versus 2D), amplitude, and frequency on postural stability were investigated by analyzing different stability measures, specifically AP/ML/2D Center-of-Pressure (COP) path length, AP/ML/2D Time-to-Boundary (TtB), and sway area. Standing postural stability was compromised more by 2D perturbations than 1D perturbations, evidenced by a significant increase in COP path length and sway area and decrease in TtB. Further, the stability decreased as 2D perturbation amplitude and frequency increased. A significant increase in COP path length and decrease in TtB were consistently observed as the 2D perturbation amplitude and frequency increased. However, sway area showed a considerable increase only with increasing perturbation amplitude but not with increasing frequency.
All civilization requires some sort of infrastructure to provide an essential service. Roads, bridges, pipelines, railroads, etc. are all critical in maintaining our society, but when they fail, they pose a serious threat to the economy, public safety, and environment. This is why it has become increasingly important to invest in and research the field of Structural Health Monitoring (SHM) to ensure the safety and reliability of our infrastructure. This research paper delves into the optimization of a Lizard-inspired Tube Inspection (LTI) robot, with the primary focus on the inspection side of SHM through the use of Electro Magnetic Acoustic Transducer (EMAT), a Non-Destructive Testing (NDT) method. The robot is designed to inspect power plants piping for damage or defects, and its ability to detect issues early, results in improved plant efficiency, enhanced structural data collection, and increased safety. An iterative, reliable design was constructed by reducing the weight and addressing previous design flaws and then tested. Solidworks was used to calculate theoretical weight, applied stress, and displacements for the design modifications.. The overall reduction in weight was around 12.4% of the previous design. While this research successfully reduced the robot's weight and resolved issues in its design, further optimization is still necessary. Future studies should investigate the finger and friction pad design, robot control, and ways to reduce the reliance on commercial off-the-shelf parts. This will expand the robot’s inspection capabilities, making it applicable in other industries where NDT is critical to ensure structural integrity and safety, such as the pipes in oil and gas refineries, water treatment plants, and chemical processing plants, innovating the way infrastructure is monitored and maintained.