Design and Experiments of a Novel Humanoid Robot with Parallel Architectures

In this paper, the mechanical design of the LARMbot 2, a low-cost user-oriented humanoid robot was presented. LARMbot 2 is characterized by parallel architectures for both the torso and legs. The proposed design was presented with the kinematics of its main parts—legs, torso, arms—and then compared to its previous version, which was characterized by a different leg mechanism, to highlight the advantages of the latest design. A prototype was then presented, with constructive details of its subsystems and its technical specifications. To characterize the performance of the proposed robot, experimental results were presented for both the walking and weight-lifting operations

Functional mimicry of Ruffini receptors with fibre Bragg gratings and deep neural networks enables a bio-inspired large-area tactile-sensitive skin

Collaborative robots are expected to physically interact with humans in daily living and the workplace, including industrial and healthcare settings. A key related enabling technology is tactile sensing, which currently requires addressing the outstanding scientific challenge to simultaneously detect contact location and intensity by means of soft conformable artificial skins adapting over large areas to the complex curved geometries of robot embodiments. In this work, the development of a large-area sensitive soft skin with a curved geometry is presented, allowing for robot total-body coverage through modular patches. The biomimetic skin consists of a soft polymeric matrix, resembling a human forearm, embedded with photonic fibre Bragg grating transducers, which partially mimics Ruffini mechanoreceptor functionality with diffuse, overlapping receptive fields. A convolutional neural network deep learning algorithm and a multigrid neuron integration process were implemented to decode the fibre Bragg grating sensor outputs for inference of contact force magnitude and localization through the skin surface. Results of 35 mN (interquartile range 56 mN) and 3.2 mm (interquartile range 2.3 mm) median errors were achieved for force and localization predictions, respectively. Demonstrations with an anthropomorphic arm pave the way towards artificial intelligence based integrated skins enabling safe human–robot cooperation via machine intelligence

Open-loop position control in collaborative, modular Variable-Stiffness-Link (VSL) robots

— Collaborative robots (cobots) open up new avenues in the fields of industrial robotics and physical Human-Robot Interaction (pHRI) as they are suitable to work in close approximation and in collaboration with humans. The integration and control of variable stiffness elements allow inherently safe interaction. Apart from notable work on Variable Stiffness Actuators, the concept of Variable-Stiffness-Link (VSL) manipulators promises safety improvements in cases of unintentional physical collisions. However, position control of these type of robotic manipulators is challenging for critical task-oriented motions (e.g., pick and place). Hence, the study of open-loop position control for VSL robots is crucial to achieve high levels of safety, accuracy and hardware cost-efficiency in pHRI applications. In this paper, we propose a hybrid, learning based kinematic modelling approach to improve the performance of traditional open-loop position controllers for a modular, collaborative VSL robot. We show that our approach improves the performance of traditional open-loop position controllers for robots with VSL and compensates for position errors, in particular, for lower stiffness values inside the links: Using our upgraded and modular robot, two experiments have been carried out to evaluate the behaviour of the robot during taskoriented motions. Results show that traditional model-based kinematics are not able to accurately control the position of the end-effector: the position error increases with higher loads and lower pressures inside the VSLs. On the other hand, we demonstrate that, using our approach, the VSL robot can outperform the position control compared to a robotic manipulator with 3D printed rigid links

Rotorcraft Blade Pitch Control Through Torque Modulation

Micro air vehicle (MAV) technology has broken with simple mimicry of manned aircraft in order to fulfill emerging roles which demand low-cost reliability in the hands of novice users, safe operation in confined spaces, contact and manipulation of the environment, or merging vertical flight and forward flight capabilities. These specialized needs have motivated a surge of new specialized aircraft, but the majority of these design variations remain constrained by the same fundamental technologies underpinning their thrust and control. This dissertation solves the problem of simultaneously governing MAV thrust, roll, and pitch using only a single rotor and single motor. Such an actuator enables new cheap, robust, and light weight aircraft by eliminating the need for the complex ancillary controls of a conventional helicopter swashplate or the distributed propeller array of a quadrotor. An analytic model explains how cyclic blade pitch variations in a special passively articulated rotor may be obtained by modulating the main drive motor torque in phase with the rotor rotation. Experiments with rotors from 10 cm to 100 cm in diameter confirm the predicted blade lag, pitch, and flap motions. We show the operating principle scales similarly as traditional helicopter rotor technologies, but is subject to additional new dynamics and technology considerations. Using this new rotor, experimental aircraft from 29 g to 870 g demonstrate conventional flight capabilities without requiring more than two motors for actuation. In addition, we emulate the unusual capabilities of a fully actuated MAV over six degrees of freedom using only the thrust vectoring qualities of two teetering rotors. Such independent control over forces and moments has been previously obtained by holonomic or omnidirection multirotors with at least six motors, but we now demonstrate similar abilities using only two. Expressive control from a single actuator enables new categories of MAV, illustrated by experiments with a single actuator aircraft with spatial control and a vertical takeoff and landing airplane whose flight authority is derived entirely from two rotors

Design of Compliance Assisted Gaits for a Quadrupedal Amphibious Robot

The goal of this thesis was to develop an amphibious legged quadrupedal robot and associated gaits. Gaits of interest included walking, swimming, and smoothly transitioning between the two. Compliance was employed in the robot's legs to achieve swimming. Various types and configurations of compliant legs were evaluated using physical experiments and simulation. Three primary, two secondary, and two transition gaits were developed. An algorithm was developed to determine the appropriate course of action based on the current gait performance and the desired performance. The robot developed in this thesis met the goals of the design and demonstrated the technical feasibility of using compliance in amphibious legged robots

LineFORM: Actuated Curve Interfaces for Display, Interaction, and Constraint

In this paper we explore the design space of actuated curve interfaces, a novel class of shape changing-interfaces. Physical curves have several interesting characteristics from the perspective of interaction design: they have a variety of inherent affordances; they can easily represent abstract data; and they can act as constraints, boundaries, or borderlines. By utilizing such aspects of lines and curves, together with the added capability of shape-change, new possibilities for display, interaction and body constraint are possible. In order to investigate these possibilities we have implemented two actuated curve interfaces at different scales. LineFORM, our implementation, inspired by serpentine robotics, is comprised of a series chain of 1DOF servo motors with integrated sensors for direct manipulation. To motivate this work we present various applications such as shape changing cords, mobiles, body constraints, and data manipulation tools

A Review of Non-Invasive Haptic Feedback stimulation Techniques for Upper Extremity Prostheses

A sense of touch is essential for amputees to reintegrate into their social and work life. The design of the next generation of the prostheses will have the ability to effectively convey the tactile information between the amputee and the artificial limbs. This work reviews non-invasive haptic feedback stimulation techniques to convey the tactile information from the prosthetic hand to the amputee’s brain. Various types of actuators that been used to stimulate the patient’s residual limb for different types of artificial prostheses in previous studies have been reviewed in terms of functionality, effectiveness, wearability and comfort. The non-invasive hybrid feedback stimulation system was found to be better in terms of the stimulus identification rate of the haptic prostheses’ users. It can be conclude that integrating hybrid haptic feedback stimulation system with the upper limb prostheses leads to improving its acceptance among users