Open Source VSA-CubeBots for Rapid Soft Robot Prototyping

Nowadays, rapid robot prototyping is a desired capability of any robotics laboratory. Combining the speed of 3D plastic printing and the use of custom Open Source electronic hardware/software solutions, our laboratory successfully developed and used tools related to variable impedance robot technology. This paper describes how we capitalized the design and use of one kind of variable stiffness actuators as a modular tool to prototype and test in a quick fashion several robot capabilities. The extension of such a modular tool for rapid prototyping allowed us to use it in several applications and scenarios, including the educational setting, aiming to speed up the gap between theory and practice in robotics. The complete palette of developments of our laboratory in hardware/software as well as some robotic systems applications shown here, are open source and contribute to the Natural Motion Initiative

Variable stiffness control for oscillation damping

In this paper a model-free approach for damping control of Variable Stiffness Actuators is proposed. The idea is to take advantage of the possibility to change the stiffness of the actuators in controlling the damping. The problem of minimizing the terminal energy for a one degree of freedom spring-mass model with controlled stiffness is first considered. The optimal bang-bang control law uses a maximum stiffness when the link gets away from the desired position, i.e. the link velocity is decreasing, and a minimum one when the link is going towards it, i.e. the link velocity is increasing. Based on Lyapunov stability theorems the obtained law has been proved to be stable for a multi-DoF system. Finally, the proposed control law has been tested and validated through experimental tests

ZigBee - Ethernet gateway design

ZigBee is a standard protocol for the realisation of wireless sensor networks for many applications from home automation to industrial management, from security to entertainment, but, like every wireless networks has a big weakness. It is limited to the geographical area where it is installed. The worldwide access to these kind of networks is the key problem and the reason why we wanted to design a device capable of interconnecting a ZigBee network with the Internet. First of all we made a research on the available hardware to realise a custom board to fit our needs. Then we concentrate our attention on the implementa- tion of the firmware which is the main subject of this thesis. The obtained results are quite satisfying and aligned with the actual com- mercial solutions. We can assert that we have completed an important part of a larger flexible infrastructure which will make possible the remote management of wireless networks in a wide set of uses