Dynamic modeling of a parallel manipulator-based mobility assistive device for elderly people

Recently, more attention has been paid for assisting elderly and people with various disabilities, hence assistive robots have gained much popularity. These robots are usually in a direct contact with the user, therefore dynamic modeling is important for precise control. In this paper, dynamic model for a parallel manipulator-based mobility assistive device is first developed using the first type of Lagrange´s equations and simulated using MATLAB software. Also, a CAD model of the device is simulated using ADAMS dynamic simulation software for comparison. Both simulations are performed using the same system parameters and end-effector trajectory. In these simulations, the natural trajectory of human motion during sit to stand activity is used. This trajectory is determined using VICON human motion capturing system. Simulations show a good agreement between the results obtained using the dynamic model and the ones obtained using ADAMS software with a root mean square error less than 0.2% for all calculated results.