Parallel manipulators have some special properties in comparison to serial robots,rnmaking them increasingly appealing in industrial applications as technology advances.rnsuch as: more rigid structure, high orientation accuracy, better control onrnthe limits of velocities and accelerations, good positioning accuracy, high payloadto-rnweight-ratio and low inertia of moving parts. On the other hand, parallelrnrobots are nonlinear multi-input multi-output (MIMO) systems whose dynamicsrnare governed by a highly nonlinear coupled, time-varying system with manyrnuncertainties such as load variation, friction and external disturbances, makingrnrobot control more di cult and necessitating a robust control system.rnThis thesis provides passivity-based control as one of the strategies for designingrnrobust controllers for a 3-DOF Delta Robot trajectory tracking. Passivity is arnfundamental attribute of many physical systems that may be nearly characterizedrnin terms of energy dissipation and transformation and its intrinsic input outputrnproperty quanti es and de nes a systemâ€™s energy balance when external inputsrnimitate to produce some outputs. Furthermore, it is a method of operating arnsystem with the goal of making the closed loop system passive. The 3-D model ofrna 3-DOF Delta robot is designed in 3D-CAD (Solidworks). Hence, this modelingrnenvironment enables to introduce real but not approximated parameters of thernrobot and eased computation of large matrixes. Dynamical model with all thernkinematic constraints for a robot will simply be found by exporting a 3D-CADrnmodel of the robot to Simscape Multibody.rnThe kinematics, dynamics and singularity analysis of the 3-DOF Delta robot hasrnbeen carried out, a passivity based controller has been designed and its performancernis tested by tracking a circular trajectory centered at (15,15,/0) on X-Y planernwith 160mm radius. The simulation result shows that the steady state tracking isrnreached in about 3 seconds for a circular trajectory and X & Y rms error of 2.88mm.The robustness of the designed controller is illustrated mathematically and thernsimulation is carried out on MATLAB, and it shows that the controller is robust tornexternal disturbances.