This paper presents a fault-tolerant method for estimating the angular rate of uncontrolled bodies in space, such as failed spacecrafts. The bodies are assumed to be free of any sensors; however, a planned mission is assumed to track several features of the object by means of stereo-vision sensors. Tracking bodies in the space environment using these sensors is not, in general, an easy task: obtainable information regarding the attitude of the body is often corrupted or partial.The developed method exploits this partial information to completely recover the attitude of the body using a basis pursuit approach. An unscented Kalman filter can then be used to estimate the angular rate of the body.

Space Debris removal is a critical issue related to space research. One of the key requirements for a removal mission is the assessment of the target rotational dynamics. Ground observations are not sufficient for reaching the accuracy level required to guide the chaser spacecraft during the capture maneuver. Moreover, the guidance and control strategy for the chaser to approach the target is a critical aspect of such missions. This paper present simulation results of two complementary methods, one for estimating the entire rotational dynamic state of the target, and the other for accurately controlling the approach maneuver. In particular, the information coming from the identification and prediction of the actual motion of the rotation axis of the target is exploited by the second method for aligning the docking interface of the chaser with that axis at the instant of capture. The dynamic estimation is based on Kalman filtering in an original combination with compressive sampling techniques for making the method robust to failures of the observation sensors. The guidance of the chaser is based on a model predictive control law. The combined simulation of the employment of the methods has revealed the feasibility of the global approach. I. .IntroductionNE of the main concerns in the space field is the high number of objects orbiting the Earth in orbits of interest for the accomplishment of scientific and communication missions. Currently, more than 10000 objects bigger than 10 cm take up Low Earth Orbit (LEO) and Geosynchronous Earth Orbit (GEO) [1].

This paper reports how a numerical controlled machine axis was studied through a lumped parameter model. Firstly, a linear model was derived in order to apply a modal analysis, which estimated the first mechanical frequency of the system as well as its damping coefficients. Subsequently, a nonlinear system was developed by adding friction through experimentation. Results were validated through the comparison with a commercial servoaxis equipped with a Siemens controller. The model was then used to evaluate the effect of the stiffness of the structural parts of the axis on its first natural frequency. It was further used to analyse precision, energy consumption, and axis promptness. Finally a cost function was generated in order to find an optimal value for the main proportional gain of the position loop.

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The use of sanitary water is a main aspect of comfort and healthiness within a house or a public environment as gyms or beauty farms. At the same time, water waste should be limited to a minimum in order to preserve both water and the energy required to warm it. To obtain these results, it is necessary to rule quickly and in a precise way the temperature. It is also necessary to check the presence of possible contemporary flow requested by different users in order to optimize distribution in the house network. This work describes a mechatronic water mixer that was developed to ensure fast and precise control of flow and temperature of delivered water. The flow control is based on modulating digital valves driven in pulse code modulation and on a microcontroller board. The electronic unit is designed to interface with a domotic network for remote control and total consumption monitoring and optimization.