This work presents a trajectory control for non-redundant serial-link manipulators that is valid for trajectories with ordinary singularities of codimension one and non-ordinary singularities of any codimension. For this purpose, several singularity classifications are considered and a procedure is developed in order to solve the indeterminate motion of non-ordinary singularities. The proposed trajectory control is validated by simulation and by experiments with the six-revolute (6R) industrial robot KUKA KR 15/2.

The popularization of fused deposition modeling (FDM) technology and open-source microcontrollers has permitted the explosion of electric hand prostheses that can be designed, shared, built, and operated at a low cost, under the Do It Yourself premise. Patients with limb reductions at the transcarpal or transradial level are best candidates to benefit from them. They manage the gross location with the remaining limb, while the built-in motors offer the possibility of controlling each finger independently. The number of mobile joints along the finger and the type of transmission can determine the quality of the grasp. Moreover, there is a need of objective procedures to assess the functionality of complete prototypes at reasonable effort. This work makes a critical review of the different transmission systems that can be found in most low-cost finger designs: linkage and tendon mechanisms. Mechanical performance has been analyzed using a standardized model of the index finger. Furthermore, robotic grasp quality metrics (GQM) have been used to evaluate by simulation the functionality of complete devices. Neither finger transmission design appeared clearly advantageous in the range of flexion studied. The evaluation of the complete devices gave slightly better quality grades for the linkage-driven model. Instead, tendon-driven model achieved a greater quantity of successful grasps. In the current state of art, some other aspects may have led to a dominant situation of the tendon-driven hands: fewer number of parts to be printed, easier assembly for a nonexpert user, advantageous in pursuit of lightweight devices.

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This paper deals with the tuning of a complex robotic workcell of eight joints devoted to milling tasks. It consists of a KUKA TM manipulator mounted on a linear track and synchronised with a rotary table. Prior to any machining, the additional joints require an in situ calibration in an industrial environment. For this purpose, a novel planar calibration method is developed to estimate the external joint configuration parameters by means of a laser displacement sensor and avoiding direct contact with the pattern. Moreover, a redundancy resolution scheme on the joint rate level is integrated within a CAM system for the complete control of the workcell during the path tracking of a milling task. Finally, the whole system is tested in the prototyping of an orographic model.