Research Of An Intelligent Walking-Aid Robot And Its Motion Control

With China's entering an aging society, the number of geriatric has been increasing year by year, which results in the scarcity of nursing resources. Medical theory and practice show that scientific rehabilitation training method and assisting device can help the aged and disabled improve their physical fitness and recover the body function. In order to meet the needs of daily walk for the elderly and the disabled, researchers from home and abroad have been devoting themselves to developing the lower limbs rehabilitative robots for walking aid. The research and development of rehabilitation robot starts relatively late in China and results less, in addition, most of them are not suitable for the aged. Therefore, the research and development of rehabilitation robot is the exigent need of the society.In this paper, we developed an intelligent lower limbs rehabilitative walking-aid robot based on force sensor array and tilt angle sensors. Firstly, this article put forward the research plan of the intelligent walking-aid rehabilitation robot on the basis of summarizing the related literatures at home and abroad. And then, this paper proposed the design of the overall mechanical structure of the walking-aid robot with security, stability and flexibility, and introduced the design of the human-robot force interaction interface in detail. In the meantime, we introduced the design and development of the sensory system of the walkingaid robot. And then the control system was proposed in detail, including the development of the software, hardware and the communication protocol. In the aspect of control algorithm, we firstly put forward the method of the human motion intention recognition algorithm, and then carried on the research of variable damping admittance control based on the force interaction model, the admittance control model. In addition,we proposed the gravity compensation algorithm to enhance the environment adaptability of the walking-aid robot system. Finally, according to the control algorithms above, we conducted a series of walking-assist experiments with the walking-aid robot system. There are three typical experiments, the basic walking-assist experiment, the variable damping admittance control experiment and gravity compensation experiment. According to the analysis of experimental data, we demonstrated the rationality of the design of the robot mechanism and the effectiveness of the related control algorithms, and made evaluation of the performance and adaptability of the robot system.The walking-aid robot system this paper proposed has five characteristics as follows:(1) A new overall structure is designed, with the combination of the flexibility and mobility of the active omnidirectional driving mechanism, and the stability and interaction security of the auxiliary support mechanism.(2)The application of variable damping admittance control promoted the robot performance in each stage of a human-robot interactive activity.(3)Taking the user's comfort into consideration when turning, a new method of human motion intention recognition is put forward by detailed modeling analysis;(4)The application of the gravity compensation algorithm enhanced the environmental adaptability of the robot system.(5) With a simple and friendly user interface, a convenient and effective operation interface, and relatively low cost, the walking-aid robot is easy to develop for productization.