Research and development of parallel kinematic machines (hereafter called PKMs) is being performed more and more actively. The methodologies for PKMs development are considered as the key for the robot applications in the future.

PKMs feature many advantages over serial robots in terms of accuracy, stiffness, structural rigidity, dynamic agility, and compactness. However, PKMs have a few of disadvantages such as treacherous singularities and limited workspace.

The study reported is on design and analysis of a PKM with 3 degrees of freedom (DOF). The new PKM is designed as a machine tool in various applications in manufacturing. The PKM is optimized based on the developed stiffness model. Kinematics and dynamics of the new PKM is also modeled and simulated. The thesis is organized as follows.

First, the 3-DOF PKM is designed. Its topology is introduced and a CAD model of the final design is created. The inverse kinematics is analyzed. Jacobian matrix and velocity equations are derived. The singularities of the PKM structure are studied.

Second, the workspace of the new PKM is studied. The concept of the workspace is defined. Three methods for the calculation of workspace are compared, and the results are illustrated.

Third, Static Balancing of the Parallel Kinematic Manipulator is investigated:​ the definition and methodology of static balancing are introduced. Two methods called Adjusting Kinematic Parameters (AKP) and counterweights are applied to the structure and the counterweights method leads to static balancing of the PKM. The conditions of static balancing are given.

Fourth, the stiffness of the 3-DOF Parallel Kinematic Machine is analyzed. The literatures on the methodologies of stiffness analysis are surveyed. The stiffness model of the proposed PKM is established, the stiffness matrix is utilized, the stiffness mapping is generated, and the optimization of the global stiffness of the 3-DOF PKM is performed.

Finally, the dynamic model of the new PKM is studied. It describes the relationship between the driving forces and the motion of the end-effector platform. Two approaches, the Newton-Euler and the Lagrange methods, are compared and the later one is selected to build the dynamic model of the 3-DOF Parallel Kinematic Machine.

The new 3-DOF PKM combining the spatial rotational and translational degrees of freedom has varied advantages and good potential applications of manufacturing. The novel design leads to the very efficient models in kinematic, workspace, stiffness and dynamic analyses. For the focus of the system stiffness, the study of this thesis gives the solution of how to reconfigure a parallel kinematic machine with adjusting kinematic parameters and path re-planning to achieve a desired stiffness. The optimal design value parameters are also suggested for the achieved maximum global stiffness of the PKM.