Nonlinear Disturbance Observer Based Control of a 7DoF Exoskeleton Robot for Arm Movements HOUDA BARBOUCH Universit´ e Tunis Elmanar ´ Ecole Natinale d’Ing´ enieurs de Tunis ENIT Laboratoire RISC BP,37 le Belv´ ed` ere,1002Tunis TUNISIA barbouchhouda@yahoo.fr ABDERRAOUF KHEMIRI Universit´ e Tunis Elmanar ´ Ecole Natinale d’Ing´ enieurs de Tunis ENIT Laboratoire RISC BP,37 le Belv´ ed` ere,1002 Tunis TUNISIA khemiri.abderraouf@yahoo.fr NAHLA KHRAIEF Universit´ e Tunis Elmanar ´ Ecole Natinale d’Ing´ enieurs de Tunis ENIT Laboratoire RISC BP,37 le Belv´ ed` ere,1002 Tunis TUNISIA khraiefnahla@yahoo.fr SAFYA BELGHITH Universit´ e Tunis Elmanar ´ Ecole Natinale d’Ing´ enieurs de Tunis ENIT Laboratoire RISC BP,37 le Belv´ ed` ere,1002Tunis TUNISIA safyabelghith@yahoo.fr Abstract: This paper focuses on the application of a disturbance observer control of an exoskeleton upper- extremity. In order to achieve this target, arm two steps were executed; first of all, a prototype of the exoskeleton robot has been designed using Solidworks software, after its dynamic model has been accomplished. Then, the development of non linear controller (Computed Torque Control) was performed. Finally, to the application of a disturbance observer in the control, we have used the Lyapunov method to estimate the external disturbance about the device. Key–Words: Exoskeleton robot, rehabilitation, physical disability, Computed Torque Control, Nonlinear Distur- bance Observer, External disturbance, Lyapunov method. L A T E X 1 Introduction The partial or the full loss of motor human limbs is known especially of the elderly people as it may occur due a stroke or sports injuries, occupational injuries, or trauma and spinal cord injuries.. In recent decades, an enormous increase has been pre- sented in the number of such cases. But the dura- tion of treatment becames longer.In order to improve the quality of therapies, including intensity, robotics has made its appearance quite naturally in this area of rehabilitation as an evolution of existing mechan- ical devices. In this context of neuro-motor rehabil- itation robotics upper limb that the researchers have developed a wide of exoskeleton systems. These devices are characterized by the number of degrees of freedom, joints with which they are destined to interact(Shoulder, Elbow, Wrist, Fingers ), the na- ture of their actuator (electric, hydraulic, pneumatic...) and the technology power transmission (gears, cables, rods...). Among these different devices may be found: MGA (Maryland Georgetown-Army) Exoskeleton [?] [?] is a robotic arm with five degrees of freedom ded- icated to the rehabilitation of pathological shoulder. This exoskeleton arm will evaluate strength, speed and range of motion. ARMin I, II and III [?][?] is an exoskeleton with six degrees of freedom and equipped by position and force sensors. Also, it’s equipped by a multimodal display system (visual and audio feed- back). The ARMin enables us to offer a virtual im- mersion for the limb to make simple games or ADL (Activities of Daily Living) of the patient. CADEN- 7 (Washington University) Exoskeleton [?][?][?] was designed by a team from the University of Washing- ton Which has seven degrees of freedom. They were interested in the problems of singularities. The de- vice and the patient’s limb are connected via various force sensors to allow the use of force control. In the aim of obtaining sufficient transparency, the team added EMG signals to the control. Soft-Actuated Ex- oskeleton [?][?] is an exoskeleton with seven degrees of freedom. This latter is equipped by pneumatic muscles, that moves the seven active joints, to con- trol the stiffness of each joint as well as to provide a smoother interaction ensuring safety to the user. Fi- nally, ETS-MARSE [?][?], is a lightweight robot with seven DoFs, it controls all the joints of the upper limb. This robot has a optimal ratio of power / weight and is able to compensate the gravity efficiently. This article deals with the modeling,the control and applaying a disturbance observer based on Lyapunov method of an exoskeleton upper-extremity with seven degrees of freedom. This paper is organized as follows: Section 2 deals with the Human arm anatomy. Section 3 deals with two points: First point describes the mechanical modeling of the proposed prototype. Second point Houda Barbouch et al. International Journal of Control Systems and Robotics http://www.iaras.org/iaras/journals/ijcsr ISSN: 2367-8917 242 Volume 2, 2017