Decentralized Trajectory Tracking Control for Soft Robots Interacting With the Environment

Despite the classic nature of the problem, trajectory tracking for soft robots, i.e., robots with compliant elements deliberately introduced in their design, still presents several challenges. One of these is to design controllers which can obtain sufficiently high performance while preserving the physical characteristics intrinsic to soft robots. Indeed, classic control schemes using high-gain feedback actions fundamentally alter the natural compliance of soft robots effectively stiffening them, thus de facto defeating their main design purpose. As an alternative approach, we consider here using a low-gain feedback, while exploiting feedforward components. In order to cope with the complexity and uncertainty of the dynamics, we adopt a decentralized, iteratively learned feedforward action, combined with a locally optimal feedback control. The relative authority of the feedback and feedforward control actions adapts with the degree of uncertainty of the learned component. The effectiveness of the method is experimentally verified on several robotic structures and working conditions, including unexpected interactions with the environment, where preservation of softness is critical for safety and robustness

Toward an adaptive foot for natural walking

Many walking robot presented in literature stand on rigid flat feet, with a few notable exceptions that embed flexibility in their feet to optimize the energetic cost of walking. This paper proposes a novel adaptive robot foot design, whose main goal is to ease the task of standing and walking on uneven terrains. After explaining the rationale behind our design approach, we present the design of the SoftFoot, a foot able to comply with uneven terrains and to absorb shocks thanks to its intrinsic adaptivity, while still being able to rigidly support the stance, maintaining a rather extended contact surface, and effectively enlarging the equivalent support polygon. The paper introduces the robot design and prototype and presents preliminary validation and comparison versus a rigid flat foot with comparable footprint and sole

The Quest for Natural Machine Motion: An Open Platform to Fast-Prototyping Articulated Soft Robots

Soft robots are one of the most significant recent evolutions in robotics. They rely on compliant physical structures purposefully designed to embody desired characteristics. Since their introduction, they have shown remarkable applicability in overcoming their rigid counterparts in such areas as interaction with humans, adaptability, energy efficiency, and maximization of peak performance. Nonetheless, we believe that research on novel soft robot applications is still slowed by the difficulty in obtaining or developing a working soft robot structure to explore novel applications

The Quest for Natural Machine Motion: An Open Platform to Fast-Prototyping Articulated Soft Robots

Soft robots are one of the most significant recent evolutions in robotics. They rely on compliant physical structures purposefully designed to embody desired characteristics. Since their introduction, they have shown remarkable applicability in overcoming their rigid counterparts in such areas as interaction with humans, adaptability, energy efficiency, and maximization of peak performance. Nonetheless, we believe that research on novel soft robot applications is still slowed by the difficulty in obtaining or developing a working soft robot structure to explore novel applications. In this article, we present the Natural Machine Motion Initiative (NMMI), a modular open platform that aims to provide the scientific community with tools for fast and easy prototyping of articulated soft robots. Such a platform is composed of three main open hardware modules: the Qbmoves variable-stiffness actuators (VSAs) to build the main robotic structure, soft end effectors (EEs) to interact with the world, and a pool of application-specific add-ons. We also discuss many novel uses of the platform to rapidly prototype (RP) and test new robotic structures with original soft capabilities, and we propose NMMI-based experiments

Comparison between Thulium laser VapoEnucleation and GreenLight laser photoselective vaporization of the prostate in real-life setting: propensity score analysis

To compare in daily practice efficacy and safety of standard 180-Watt GreenLight laser photo-selective vaporization (PVP) and Thulium laser Vaporesection of the prostate (ThuVEP)

Acute β-Adrenergic Overload Produces Myocyte Damage through Calcium Leakage from the Ryanodine Receptor 2 but Spares Cardiac Stem Cells

A hyperadrenergic state is a seminal aspect of chronic heart failure. Also, “Takotsubo stress cardiomyopathy,” is associated with increased plasma catecholamine levels. The mechanisms of myocyte damage secondary to excess catecholamine exposure as well as the consequence of this neurohumoral burst on cardiac stem cells (CSCs) are unknown. Cardiomyocytes and CSCs were exposed to high doses of isoproterenol (ISO), in vivo and in vitro. Male Wistar rats received a single injection of ISO (5 mg kg(-1)) and were sacrificed 1, 3, and 6 days later. In comparison with controls, LV function was impaired in rats 1 day after ISO and started to improve at 3 days. The fraction of dead myocytes peaked 1 day after ISO and decreased thereafter. ISO administration resulted in significant ryanodine receptor 2 (RyR2) hyperphosphorylation and RyR2-calstabin dissociation. JTV519, a RyR2 stabilizer, prevented the ISO-induced death of adult myocytes in vitro. In contrast, CSCs were resistant to the acute neurohumoral overload. Indeed, CSCs expressed a decreased and inverted complement of β(1)/β(2)-adrenoreceptors and absence of RyR2, which may explain their survival to ISO insult. Thus, a single injection of ISO causes diffuse myocyte death through Ca(2+) leakage secondary to the acutely dysfunctional RyR2. CSCs are resistant to the noxious effects of an acute hyperadrenergic state and through their activation participate in the response to the ISO-induced myocardial injury. The latter could contribute to the ability of the myocardium to rapidly recover from acute hyperadrenergic damage