Safety accidents related to falls and collisions involving strollers occur every year. To address this issue, an automatic brake system has been developed and tested for strollers. Previous systems were only functionally verified and did not confirm structural safety until the brakes were activated and came to a stop. Given that this system is a safety-critical device, a prototype was manufactured and tested to ensure the device's safety during brake operation. Additionally, structural analysis was conducted using the collected data to identify potential vulnerabilities.

This paper examines the stability of the blades that convert the wind kinetic energy into the mechanical energy among the small wind power-generation systems, and proposes the design improvement for blades with a higher rigidity and a lighter weight than the conventional blades. The composite-specimen tensile test and static-load test are conducted to verify the reliability. To design the lightweight blade with the high stiffness, the displacement and the safety factor of the blade composed of the composite material are calculated from the structural-analysis results, and the optimal dimensional and material designs are performed. The optimal design parameters are selected by the shear-web lamination angle and the lamination thickness. The objective function is selected by the safety factor and the weight. For the optimum material design, the GFRP is converted into the CFRP. In this paper, the structural improvement is performed by optimizing the dimensional and material designs, the blade stiffness and weight are redesigned and compared with those of the designed blades, and the structural stability of the redesigned blades is also examined.