Study of redundant kinematics for industrial manipulators: case study of the 7 axes robot

The objective of this Master thesis is the managing, the development and the integration of the Comau 7 axes robot prototype in the pre-existent system software. In particular this prototype is the first redundant anthropomorphic robot, with 7 axes, for Comau.
Redundant robots have a lot of advantages compared to standard anthropomorphic robot with 6 axes and six degrees of freedom. For example these can claim a better dexterity combined with an enhanced flexibility.
On the other hand there are a lot of difficulties and problems that we have to face in order to reach our goals. First of all the methodology used to program a classical anthropomorphic robot is not completely suitable for a redundant one. A new typology and philosophy of programming has to be proposed. Moreover there are a lot of issues deriving from mathematical problems. For example, to solve the inverse kinematics (algorithm which determines the joint values that provide a desired position of the end-effector) we have to face the fact that at each position in the space, corresponds an infinite number of possible joints solutions; one of this solutions has to be selected and a method of selection has to be chosen. The classical 6 axes inverse kinematics algorithm has been suitably extended to redundant manipulators by adopting a task space augmentation technique. Formally, a functional constraint task, is imposed to be satisfied together with the end-effector task; typical constraints include obstacle avoidance, limited joints range and singularity avoidance.
First, in this thesis we will talk about the organization of the overall project development, and the advantages and disadvantages of this robot typology.
Then, will be address an analysis of the redundant robots that our competitors offer on their catalogues. We will face all the mathematical issues, as well as, the integration of this kind of robot in the pre-existent software. Finally the actual development results will be presented together to next possible steps.