On the Analysis and Development of a Semi-autonomous Robotic Platform that Increases the Mobility of Children with Cerebral Palsy

Abstract

Children with Cerebral Palsy (CP) often face di culties in mobility, as their condition may not allow them to move around in the house without support. Thus, a robotic assistive device that can increase their mobility is of paramount importance, as it can facilitate cognitive development through the exploration of their surroundings. In this project, a multi-functional mobile robot device with a detachable seat is designed, analyzed, and developed. The device proposed is modular and can be personalized according to the needs of the user. Four di erent control methods have been developed to operate the device. More precisely, the user can choose between: i) manual steering, ii) joystick based steering with Electromyography (EMG) based velocity control, iii) smartphone-based remote control, and iv) fully autonomous driving mode. For the manual control, the user has control of both the steering wheel and the throttle. By using these two components, the user is able to drive the device like an electric car. For joystick based steering and EMG based control, the user is using the muscle movement to control the acceleration and a potentiometer based joystick to control the steering. This control mode is particularly useful for users that have weak upper limbs. For remote control, the user can choose between: i) full control of the mobile robot and ii) partial remote control that is useful for parents supervising kids that drive the device. The di erent modes available on the smartphone allow the user to either choose full speed or limited speed. For the autonomous driving mode, the device is able to move towards appropriate ArUco markers and turn so as to nd the next ArUco markers, implementing desired trajectories. This mode is suitable for children who su er from severe CP conditions. Without the need to touch any control, the device can be moved around autonomously. The detachable seat can be used as a crawler by infants that su er from severe CP conditions. In addition, this thesis demonstrates the entire process of building the device. The weight of the device is 30.6 kg, and it has a turning angle of 80°. The max speed on the carpet and Noraplan Signa oor are 5.42 m/s and 5.92 m/s, respectively. The acceleration of the device can reach up to 0.64< B2 on carpet oor and 0.65 < B2 on a Noraplan Signa oor. A series of experiments have been conducted to experimentally validate the e ciency of the proposed device.