Biologically Inspired Legs and Novel Flow Control Valve Toward a New Approach for Accessible Wearable Robotics

The Humanoid Walking Robot (HWR) is a research platform for the study of legged and wearable robots actuated with Hydro Muscles. The fluid operated HWR is representative of a class of biologically inspired, and in some aspects highly biomimetic robotic musculoskeletal appendages showing certain advantages in comparison to more conventional artificial limbs and braces for physical therapy/rehabilitation, assistance of daily living, and augmentation. The HWR closely mimics the human body structure and function, including the skeleton, ligaments, tendons, and muscles. The HWR can emulate close to human-like movements even when subjected to simplified control laws. One of the main drawbacks of this approach is the inaccessibility of an appropriate fluid flow management support system, in the form of affordable, lightweight, compact, and good quality valves suitable for robotics applications. To resolve this shortcoming, the Compact Robotic Flow Control Valve (CRFC Valve) is introduced and successfully proof-of-concept tested. The HWR added with the CRFC Valve has potential to be a highly energy efficient, lightweight, controllable, affordable, and customizable solution that can resolve single muscle action

The Research on Soft Pneumatic Actuators in Italy: Design Solutions and Applications

Interest in soft actuators has increased enormously in the last 10 years. Thanks to their compliance and flexibility, they are suitable to be employed to actuate devices that must safely interact with humans or delicate objects or to actuate bio-inspired robots able to move in hostile environments. This paper reviews the research on soft pneumatic actuators conducted in Italy, focusing on mechanical design, analytical modeling, and possible application. A classification based on the geometry is proposed, since a wide set of architectures and manufacturing solutions are available. This aspect is confirmed by the extent of scenarios in which researchers take advantage of such systems’ improved flexibility and functionality. Several applications regarding bio-robotics, bioengineering, wearable devices, and more are presented and discussed

Corseto: A Kinesthetic Garment for Designing, Composing for, and Experiencing an Intersubjective Haptic Voice

We present a novel intercorporeal experience - an intersubjective haptic voice. Through an autobiographical design inquiry, based on singing techniques from the classical opera tradition, we created Corsetto, a kinesthetic garment for transferring somatic reminiscents of vocal experience from an expert singer to a listener. We then composed haptic gestures enacted in the Corsetto, emulating upper-body movements of the live singer performing a piece by Morton Feldman named Three Voices. The gestures in the Corsetto added a haptics-based \u27fourth voice\u27 to the immersive opera performance. Finally, we invited audiences who were asked to wear Corsetto during live performances. Afterwards they engaged in micro-phenomenological interviews. The analysis revealed how the Corsetto managed to bridge inner and outer bodily sensations, creating a feeling of a shared intercorporeal experience, dissolving boundaries between listener, singer and performance. We propose that \u27intersubjective haptics\u27 can be a generative medium not only for singing performances, but other possible intersubjective experiences

Design Criteria of Soft Exogloves for Hand Rehabilitation- Assistance Tasks

This paper establishes design criteria for soft exogloves (SEG) to be used as rehabilitation or assistance devices. This research consists in identifying, selecting, and grouping SEG features based on the analysis of 91 systems that have been proposed during the last decade. Thus, function, mobility, and usability criteria are defined and explicitly discussed to highlight SEG design guidelines. Additionally, this study provides a detailed description of each system that was analysed including application, functional task, palm design, actuation type, assistance mode, degrees of freedom (DOF), target fingers, motions, material, weight, force, pressure (only for fluids), control strategy, and assessment. Such characteristics have been reported according to specific design methodologies and operating principles. Technological trends are contemplated in this contribution with emphasis on SEG design opportunity areas. In this review, suggestions, limitations, and implications are also discussed in order to enhance future SEG developments aimed at stroke survivors or people with hand disabilities

Embedded fuzzy logic controller for positive and negative pressure control in pneumatic soft robots

A key challenge in soft robotics is controlling the large deformation experienced as a result of high compliance nature of soft robots. In this work, a software control strategy for regulating the amount of internal positive and negative air pressure inside pneumatic soft robots is presented. Since the air pressure has a direct effect on the amount of deformation, the position of the robot is controlled. Pressure control was implemented with a fuzzy logic controller, which is described with its performance shown. The approach can be integrated into any specified soft robotic actuator requiring pneumatic actuation e.g. bending, triangular and muscle actuators

A Retrofit Sensing Strategy for Soft Fluidic Robots

Soft robots are intrinsically capable of adapting to different environments by changing their shape in response to interaction forces with the environment. However, sensing and feedback are still required for higher level decisions and autonomy. Most sensing technologies developed for soft robots involve the integration of separate sensing elements in soft actuators, which presents a considerable challenge for both the fabrication and robustness of soft robots due to the interface between hard and soft components and the complexity of the assembly. To circumvent this, here we present a versatile sensing strategy that can be retrofitted to existing soft fluidic devices without the need for design changes. We achieve this by measuring the fluidic input that is required to activate a soft actuator and relating this input to its deformed state during interaction with the environment. We demonstrate the versatility of our sensing strategy by tactile sensing of the size, shape, surface roughness and stiffness of objects. Moreover, we demonstrate our approach by retrofitting it to a range of existing pneumatic soft actuators and grippers powered by positive and negative pressure. Finally, we show the robustness of our fluidic sensing strategy in closed-loop control of a soft gripper for practical applications such as sorting and fruit picking. Based on these results, we conclude that as long as the interaction of the actuator with the environment results in a shape change of the interval volume, soft fluidic actuators require no embedded sensors and design modifications to implement sensing. We believe that the relative simplicity, versatility, broad applicability and robustness of our sensing strategy will catalyze new functionalities in soft interactive devices and systems, thereby accelerating the use of soft robotics in real world applications

Remote-controlled ambidextrous robot hand actuated by pneumatic muscles: from feasibility study to design and control algorithms

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University LondonThis thesis relates to the development of the Ambidextrous Robot Hand engineered in Brunel University. Assigned to a robotic hand, the ambidextrous feature means that two different behaviours are accessible from a single robot hand, because of its fingers architecture which permits them to bend in both ways. On one hand, the robotic device can therefore behave as a right hand whereas, on another hand, it can behave as a left hand. The main contribution of this project is its ambidextrous feature, totally unique in robotics area. Moreover, the Ambidextrous Robot Hand is actuated by pneumatic artificial muscles (PAMs), which are not commonly used to drive robot hands. The type of the actuators consequently adds more originality to the project. The primary challenge is to reach an ambidextrous behaviour using PAMs designed to actuate non-ambidextrous robot hands. Thus, a feasibility study is carried out for this purpose. Investigating a number of mechanical possibilities, an ambidextrous design is reached with features almost identical for its right and left sides. A testbench is thereafter designed to investigate this possibility even further to design ambidextrous fingers using 3D printing and an asymmetrical tendons routing engineered to reduce the number of actuators. The Ambidextrous Robot Hand is connected to a remote control interface accessible from its website, which provides video streaming as feedback, to be eventually used as an online rehabilitation device. The secondary main challenge is to implement control algorithms on a robot hand with a range twice larger than others, with an asymmetrical tendons routing and actuated by nonlinear actuators. A number of control algorithms are therefore investigated to interact with the angular displacement of the fingers and the grasping abilities of the hand. Several solutions are found out, notably the implementations of a phasing plane switch control and a sliding-mode control, both specific to the architecture of the Ambidextrous Robot Hand. The implementation of these two algorithms on a robotic hand actuated by PAMs is almost as innovative as the ambidextrous design of the mechanical structure itself

Bi-Modal Control of Vacuum-Powered Soft Pneumatic Actuators with Embedded Liquid Metal-Based Strain Sensitive Skin

Soft robotic systems are composed of active and passively deformable structures which are intrinsically compliant, flexible, and elastic. Although these features offer benefits of adaptability, robustness, and safety, controlling these types of robots is a significant challenge, in part from the difficulty of obtaining feedback from sensors which provide state information without hindering the advantageous material properties which grant these systems their unique mechanical behavior. We demonstrate here the first integration of a flexible, stretchable, liquid metal-based strain sensor with vacuum powered soft pneumatic actuators (V-SPAs) for simultaneous controlled feedback of the soft actuators as well as user input and soft robotic device interaction. The soft sensors which are encapsulated within a Polydimethylsiloxane (PDMS) membrane are directly embedded in the outer body skin of the soft actuators, and can be used to correlate the deformation of the body under vacuum actuation to overall actuator strain or to detect external disturbances. This information is used to compute and control the angle of a rotational 3-DoF actuator module, as well as detect implicit user input control signals by direct interaction without the need for an external control interface. The dual use of embedded sensing shown in this work provides a fundamental strategy for soft collaborative robot applications