Research and Development of Wheelchair Assisted Intelligent Boarding and Landing Device for Barrier-Free Bus Based on TRIZ Theory

With the intensifying global trend of population aging, enhancing public-transport accessibility for seniors and people with disabilities has become critical. Current wheelchair-assist boarding devices on low-floor buses suffer from cumbersome operation, excessive space occupation, poor adaptation to varying curb heights, and an inability to modulate power output dynamically, all of which compromise travel convenience. This study applies TRIZ theory to solve these problems. Functional analysis, causal-chain analysis, and the nine-screen method were used to identify key issues: excessive space use, insufficient dynamic power adjustment, poor curb-height adaptability, and the lack of self-service capability. TRIZ tools— including the contradiction matrix, substance-field models, and the Ideal Final Result (IFR)—generated conceptual solutions such as a foldable ramp, an adaptive tilting mechanism, an intelligent power-assist system, and an automatic extension device. The resulting integrated unit employs a planetary-gear train combined with a four-bar linkage for compact folding, a servo motor with torque-limiting springs for adaptive height adjustment, torque sensors for real-time power modulation, and a scissor-type telescoping mechanism for automatic stowage. Experimental validation through 50 trials showed that the device completes extension/folding in 7 s, achieves angle adjustment within 3.5 s, covers a pitch range of 0°–43°, and attains a 100 % extension success rate. These features significantly increase automation, adaptability, and user independence, thereby improving the quality of accessible bus services.