Editorial

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The Morphological Computation Principles as a New Paradigm for Robotic Design

A theory, by definition, is a generalization of some phenomenon observations, and a principle is a law or a rule that should be followed as a guideline. Their formalization is a creative process, which faces specific and attested steps. The following sections reproduce this logical flow by expressing the principle of Morphological Computation as a timeline: firstly the observations of this phenomenon in Nature has been reported in relation with some recent theories, afterward it has been linked with the current applications in artificial systems and finally the further applications, challenges and objectives will project this principle into future scenarios

A bistable soft gripper with mechanically embedded sensing and actuation for fast closed-loop grasping

Soft robotic grippers are shown to be high effective for grasping unstructured objects with simple sensing and control strategies. However, they are still limited by their speed, sensing capabilities and actuation mechanism. Hence, their usage have been restricted in highly dynamic grasping tasks. This paper presents a soft robotic gripper with tunable bistable properties for sensor-less dynamic grasping. The bistable mechanism allows us to store arbitrarily large strain energy in the soft system which is then released upon contact. The mechanism also provides flexibility on the type of actuation mechanism as the grasping and sensing phase is completely passive. Theoretical background behind the mechanism is presented with finite element analysis to provide insights into design parameters. Finally, we experimentally demonstrate sensor-less dynamic grasping of an unknown object within 0.02 seconds, including the time to sense and actuate

Editorial: Advances in Modeling and Control of Soft Robots

The research leading to these results has received funding from the HUMASOFT project, with reference DPI2016-75330-P, funded by the Spanish Ministry of Economy and Competitiveness, and from RoboCity2030-DIH-CM, Madrid Robotics Digital Innovation Hub (Robótica aplicada a la mejora de la calidad de vida de los ciudadanos, FaseIV; S2018/NMT-4331), funded by “Programas de Actividades I+D en la Comunidad de Madrid” and cofunded by Structural Funds of the EU

Editorial: Advances in soft robotics based on outputs from IROS 2018

The research leading to these results has received funding from the HUMASOFT project, with reference DPI2016-75330-P, funded by the Spanish Ministry of Economy and Competitiveness, and from RoboCity2030-DIH-CM, Madrid Robotics Digital Innovation Hub (Robótica aplicada a la mejora de la calidad de vida de los ciudadanos, FaseIV; S2018/NMT-4331), funded by Programas de Actividades I+D en la Comunidad de Madrid and co-funded by Structural Funds of the EU

A soft unmanned underwater vehicle with augmented thrust capability

The components which could make Soft Unmanned Underwater Vehicles a winning technology for a range of marine operations are addressed: these include vortex-enhanced thrust, added mass recovery and high degree of compliance of the vehicle. Based on these design criteria and recent advancement in soft-bodied, pulsed-jet thrusters, a new underwater vehicle is developed and tested

Cephalopod-inspired soft robots: design criteria and modelling frameworks

Cephalopods (i.e. octopuses and squids) are taken as a source of inspiration for the development of a new kind of underwater soft robot. These cephalopod-inspired, soft-bodied vehicles entail a hollow, elastic shell capable of performing a routine of recursive ingestion and expulsion of discrete slugs of fluids via the actual inflation and deflation of the elastic chamber. This routine allows the vehicle to propel itself in water in a very similar fashion to that of cephalopods. This mode of pulsed jetting enabled by the actual body shape variations can ideally benefit from the positive feedback provided by impulse-rich discontinuous jet formation and added mass recovery. This work is complemented by extensive modelling efforts which are meant to aid in the process of mechanical design optimization as well as providing an advanced tool for biomechanical studies of living cephalopods

Forward speed control of a pulsed-jet soft-bodied underwater vehicle

This paper reports on the development of the control for a new class of soft underwater vehicles. These vehicles exploit their soft-bodied nature to produce thrust by cyclically ingesting and expelling ambient fluid. A forward speed control based on the linearised dynamics of the robot is design. The control succeeds at dealing with the discontinuous thrust by accounting for the shape-change driven actuation

Neurophysiological models of gaze control in Humanoid Robotics

This work present a robotic implementation of a neurophysiological model of rapid orienting gaze shifts in humans, with the final goal of model parameters validation and tuning. The quantitative assessment of robot performance confirmed a good ability to foveate the target with low residual errors around the desired target position. Furthermore, the ability to maintain the desired position was good and the gaze fixation after the saccadic movement was executed with only few oscillations of the head and eye. This is because the model required a very high dynamic. 9.1. Robotic point of view The head and eye residual oscillations increase linearly with increasing amplitude. In Fig. 16 is evident that the residual gaze oscillation is less than head. This is explained with the compensation introduced by the eye oscillations which compensate the gaze which becomes more stable. We explain these findings by observing that the accelerations required to execute (or stopand-invert) the movement are very high especially for the eye movement. Even if the robotic head was designed to match the human performances (in terms of angle and velocities) in its present configuration it is still not capable produce such accelerations. This is particularly evident for the movement of the eye because the motor has to invert its rotation when the fixation point is first achieved. With respect to the timing of the movement it has been found that the results of the experiments are in close accordance to the data available on humans (Goossens and Van Opstal, 1997). The same conclusion may be drawn for the shapes of the coordinated movement that can be directly compared to the typical examples reported in Fig. 14. Figure 16, 17 show that the model is capable of providing inadequate control of the redundant platform. The system response is very fast, due to the robotic head platform design. TGst time take into account the problem of eye-head coordination and the very high acceleration. The head is voluntarily delayed less than 30 millisecond after eye movement, according to human physiology, by means of Ph block (Goossens and Van Opstal ,1997). 9.2. Neurophysiological point of view A typical robotic eye-head movement is shows in Fig. 14

A general method for the design and fabrication of shape memory alloy active spring actuators

Shape memory alloys have been widely proposed as actuators, in fields such as robotics, biomimetics and microsystems: in particular spring actuators are the most widely used, due to their simplicity of fabrication. The aim of this paper is to provide a general model and the techniques for fabricating SMA spring actuators. All the steps of the design process are described: a mechanical model to optimize the mechanical characteristic for a given requirement of force and available space, and a thermal model for the estimation of the electrical power needed for activation. The parameters of both models are obtained by experimental measurements, which are described in the paper. The models are then validated on springs manufactured manually, showing also the fabrication process. The design method is valid for the dimensioning of SMA springs, independently from the external ambient conditions. The influence on the actuator bandwidth was investigated for different working environments, providing numerical indications for the utilization in underwater applications. The spring characteristics can be calculated by the mechanical model with an accuracy of 5%. The thermal model allows one to calculate the current needed for activation under different ambient conditions, in order to guarantee activation in the specific loading conditions. Moreover, two solutions were found to reduce the power consumption by more than 40% without a dramatic reduction of bandwidth