Task 4

We finalized the main control of the ALEXA robot. Finally, it has the following features:

•  Functionalities to compute paths with minimal joint loads (PTP motions) and in optimum time (LIN motions)
• Generator that computes position and velocity trajectories in the joint space
• Decentralized position controllers that combine motor and joint states to reduce the elastic effects of the actuation ropes

Furthermore, we optimized the position controllers to improve the motion capabilities of the robotic arm. In parallel, we developed a new feedforward controller that adjusts the rope tension of the respective actuated joint to an operating value.

Task 5

In early December of 2011, we began to implement the image processing modules for marker and object recognition as well as visual servoing functionalities. The implementation is currently in progress. In the following month, we plan to finalize the implementation. Afterwards, we will commission the mentioned modules and run some test to evaluate them.

Task 6

In December 2011, we constructed a mounting system to attach common cable channels and the multi camera system on the stiff links of the robotic arm. Further, we produced all mounting components and installed them on the robotic arm. Currently, we renew the pull-through of all sensor and camera cables as well as its plugs. In the next step, we will commission and calibrate the camera system.