Ricerc@Sapienza

Today robotics has shown many successful strategies to solve several navigation problems. However, moving into a dynamic environment is still a challenging task. This paper presents a novel method for motion generation in dynamic environments based on real-time nonlinear model predictive control (NMPC). At the core of our approach is a least conservative linearized constraint formulation built upon the real-time iteration (RTI) scheme with Gauss- Newton Hessian approximation.

In the recent years, an increasing interest towards enhanced and more frequent operations at high altitudes has been demonstrated both by aerospace industry and academics. In particular, many institutions and companies are developing the so-called HAPS (High Altitude Platform Stations, [1] - [3] ), high altitude balloons provided with low-thrust propulsion systems able to maintain their position over a target. These vehicles are provided with power generation systems and are able to perform long-term missions of weeks or even months.

In the present study, we employed the dual task technique to explore the role of language in topographical working memory when landmarks are present along the path. We performed three experiments to mainly test the effects of language but also motor, spatial motor and spatial environment interferences on topographical working memory. We aimed to clarify both the role of language in navigational working memory per se and the extent to which spatial language interferes with the main task more than the other types of interference.

In this paper, we describe a navigation system requiring very few computational resources, but still providing performance comparable with commonly used tools in the ROS universe. This lightweight navigation system is thus suitable for robots with low computational resources and provides interfaces for both ROS and NAOqi middlewares.

Background Segond’s fracture is a well-recognised radiological
sign of an anterior cruciate ligament (ACL) tear.
While previous studies evaluated the role of the anterolateral
ligament (ALL) and complex injuries on rotational
stability of the knee, there are no studies on the biomechanical
effect of Segond’s fracture in an ACL deficient
knee. The aim of this study was to evaluate the effect of a
Segond’s fracture on knee rotation stability as evaluated by
a navigation system in an ACL deficient knee.

Background. To evaluate the effect of antero-lateral ligament (ALL) repair on the anterior- tibial translation (ATT) and the axial-tibial rotation (ATR) during the pivot-shift test with a navigation system in patient undergoing acute anterior cruciate ligament (ACL) reconstruction of acute injuries of anterolateral compartment in cases of acute ACL tears. Methods. Ten consecutive patients operated for an acute ACL reconstruction were enrolled in this prospective study.

The investigation of the role of emotional landmarks on human navigation has been
almost totally neglected in psychological research. Therefore, the extent to which
positive and negative emotional landmarks affect topographical memory as compared
to neutral emotional landmark was explored. Positive, negative and neutral affectladen
images were selected as landmarks from the International Affective Picture
System (IAPS) Inventory. The Walking Corsi test (WalCT) was used in order to test the

Visual mental imagery arises when perceptual information is accessed from memory, originating the experience of "seeing with the mind's eye". Different content-dependent brain areas in the human ventral visual stream are activated during visual mental imagery, similarly to what happens during visual perception.

Keeping oriented in the surrounding space requires an accurate representation of one's spatial position and facing direction. Although previous studies provided evidence of specific spatial codes for position and direction within room-sized and large-scale navigational environments, little is known about the mechanisms by which these spatial quantities are represented in a real small-scale environment. Here, we used two spatial tasks requiring participants to encode their own position and facing direction on a series of pictures taken from a familiar circular square.

Recently, several Countries have shown an increasing interest toward robotic or human missions to the Moon. Ascent path and orbit injection represent a crucial issue for a lunar module, because the dynamical conditions at injection affect the subsequent phases of spaceflight. This research proposes the original combination of two techniques applied to lunar ascent modules, i.e. (i) the variable-time-domain neighboring optimal guidance (VTD-NOG), and (ii) a constrained proportional-derivative (CPD) attitude control algorithm.