With the population ageing, it is a critical factor in the public transportation to erect a physical setting that fosters independent living. However, none of research studies designed a barrier free car seat device for supporting elderly and disabilities ingress or egress the vehicle, as well as sit to stand movement. In this present work, it applied ergonomics concept to design intelligent barrier free car seat device. The device is controlled by mobile application to facilitate them. Moreover, 22 healthy subjects volunteered the effect of standup assistant function experiment. The result indicates this function helps sit-to-stand sequences compared with normal movement.