This study uses a relatively novel optimization system to optimize the structure of a self-excited oscillating nozzle. The study identifies inlet radius, lower-nozzle diameter, and cavity length as key variables (combined impact >87 %); achieves a 77.39 % improvement in overall cleaning efficiency through global optimization; and explains the flow field evolution mechanism.

Self-balancing wheelchairs can help people move in tight spaces, but they must stay upright when starting from a large tilt, carrying different users, or facing sudden pushes. We developed and tested a two-stage control approach that first brings the chair back safely from larger tilts and then keeps it steady near upright. Simulations and prototype tests showed faster recovery, better stability under disturbances, and stronger tolerance to user-weight changes, supporting safer designs.