Lightweight design and encoderless control of a miniature direct drive linear delta robot

This paper presents the design, integration and experimental validation of a miniature light-weight delta robot targeted to be used for a variety of applications including the pick-place operations, high speed precise positioning and haptic implementations. The improvements brought by the new design contain; the use of a novel light-weight joint type replacing the conventional and heavy bearing structures and realization of encoderless position measurement algorithm based on hall effect sensor outputs of direct drive linear motors. The description of mechanical, electrical and software based improvements are followed by the derivation of a sliding mode controller to handle tracking of planar closed curves represented by elliptic fourier descriptors (EFDs). The new robot is tested in experiments and the validity of the improvements are verified for practical implementation

A Multistate Friction Model for the Compensation of the Asymmetric Hysteresis in the Mechanical Response of Pneumatic Artificial Muscles

These days, biomimetic and compliant actuators have been made available to the main applications of rehabilitation and assistive robotics. In this context, the interaction control of soft robots, mechatronic surgical instruments and robotic prostheses can be improved through the adoption of pneumatic artificial muscles (PAMs), a class of compliant actuators that exhibit some similarities with the structure and function of biological muscles. Together with the advantage of implementing adaptive compliance control laws, the nonlinear and hysteretic force/length characteristics of PAMs pose some challenges in the design and implementation of tracking control strategies. This paper presents a parsimonious and accurate model of the asymmetric hysteresis observed in the force response of PAMs. The model has been validated through the experimental identification of the mechanical response of a small-sized PAM where the asymmetric effects of hysteresis are more evident. Both the experimental results and a comparison with other dynamic friction models show that the proposed model could be useful to implement efficient compensation strategies for the tracking control of soft robots

Experimental Evaluation of Novel Master-Slave Configurations for Position Control under Random Network Delay and Variable Load for Teleoperation

This paper proposes two novel master-slave configurations that provide improvements in both control and communication aspects of teleoperation systems to achieve an overall improved performance in position control. The proposed novel master-slave configurations integrate modular control and communication approaches, consisting of a delay regulator to address problems related to variable network delay common to such systems, and a model tracking control that runs on the slave side for the compensation of uncertainties and model mismatch on the slave side. One of the configurations uses a sliding mode observer and the other one uses a modified Smith predictor scheme on the master side to ensure position transparency between the master and slave, while reference tracking of the slave is ensured by a proportional-differentiator type controller in both configurations. Experiments conducted for the networked position control of a single-link arm under system uncertainties and randomly varying network delays demonstrate significant performance improvements with both configurations over the past literature

Development Issues of Healthcare Robots : Compassionate Communication for Older Adults with Dementia

Although progress is being made in affective computing, issues remain in enabling the effective expression of compassionate communication by healthcare robots. Identifying, describing and reconciling these concerns are important in order to provide quality contemporary healthcare for older adults with dementia. The purpose of this case study was to explore the development issues of healthcare robots in expressing compassionate communication for older adults with dementia. An exploratory descriptive case study was conducted with the Pepper robot and older adults with dementia using high-tech digital cameras to document significant communication proceedings that occurred during the activities. Data were collected in December 2020. The application program for an intentional conversation using Pepper was jointly developed by Tanioka’s team and the Xing Company, allowing Pepper’s words and head movements to be remotely controlled. The analysis of the results revealed four development issues, namely, (1) accurate sensing behavior for “listening” to voices appropriately and accurately interacting with subjects; (2) inefficiency in “listening” and “gaze” activities; (3) fidelity of behavioral responses; and (4) deficiency in natural language processing AI development, i.e., the ability to respond actively to situations that were not pre-programmed by the developer. Conversational engagements between the Pepper robot and patients with dementia illustrated a practical usage of technologies with artificial intelligence and natural language processing. The development issues found in this study require reconciliation in order to enhance the potential for healthcare robot engagement in compassionate communication in the care of older adults with dementia

A Novel Framework for a Systematic Integration of Pneumatic-Muscle-Actuator-Driven Joints into Robotic Systems Via a Torque Control Interface

In this paper, two different torque control approaches for PMA-driven (PMA = Pneumatic muscle actuator) revolute joints are presented and tested. In previous work controllers for PMA-driven robots are typically customized for the use on a specific robotic system. In contrast, the proposed controllers define a general control interface for every robot that is actuated by PMA-driven joints. It will be shown that controlling the torque of a PMA-driven joint enables the use of standard robotic motion control frameworks, because the torque represents the natural input of the robotic equation of motion. Therefore, both proposed torque control approaches are interconnecting PMAs and their challenging characteristics on the one hand and “conventional” motion control strategies for robots on the other hand. After a detailed discussion of two different torque control approaches, we show that a torque controller handles all characteristics and dynamics of a PMA-driven joint internally, which implies that only its bandwidth and its static torque characteristic must be taken into account for the design of the outer motion control loop. This feature simplifies the integration of PMA-driven joints in robotic systems enormously, as will be demonstrated by a design of a cascade-structured, flatness-based motion controller for an exemplary robot with one degree of freedom.BMWi, ZF4007503, Development of a PMA-driven Exoskeleton for the Upper Bod

Applicazione del Digital Storytelling come risorsa per il Digital Heritage Italiano

La ricerca si \ue8 concentrata sulla valorizzazione del patrimonio culturale italiano, che \ue8 stata presentata analizzando i prodotti digitali per la valorizzazione del cultural heritage realizzati nel 2015, e pensati per un pubblico non specializzato, che sono stati categorizzati in maniera tale da individuare le tendenze di sviluppo, e come e con quale grado di frequenza \ue8 stato incorporato lo storytelling all\u2019interno delle esperienze interattive per la promozione culturale. Nell\u2019analisi dell\u2019ampia letteratura sul digital heritage e sullo storytelling, sono stati selezionati i testi sulla base della loro rilevanza storica, e della coerenza tra le ipotesi di partenza, i dati presentati, e le recenti innovazioni tecnologiche in campo digitale. Analizzando i prodotti per il digital heritage sviluppati per la promozione, e non esclusivamente per la conservazione, del patrimonio culturale per un pubblico non specializzato che possiedono anche una dimensione interattiva sono state individuate tre categorie, quella dei musei virtuali, delle esibizioni culturali, e dei serious game, che descrivono i prodotti digitali realizzati in Italia nel 2015 per la promozione del cultural heritage. Per ogni categoria \ue8 stato presentato uno studio di caso specifico che esemplifica le caratteristiche individuate nelle categorie proposte. L\u2019analisi dei legami tra storytelling e serious games ha portato alla luce una serie di problematiche e criticit\ue0, in particolare nel rapporto tra l\u2019agency del videogiocatore e una struttura narrativa fortemente vincolante. Per superare questo problema, \ue8 stato proposto l\u2019utilizzo dei drama manager, software in grado di \u201cprevedere\u201d e controllare le scelte del videogiocatore, che potrebbero, anche nel caso del digital heritage, limitare i comportamenti distruttivi, che sono antitetici ai valori positivi che si accompagnano alla valorizzazione culturale, e al contempo salvaguardare quantomeno il senso di agency del videogiocatore. L\u2019analisi dei virtual enviroments e dell\u2019evoluzione di concetti come presence, agency, flow, enjoyment ha permesso di dimostrare come il ruolo dell\u2019utente, nel caso del digital heritage il visitatore, sia centrale per creare enriched spaces in grado di generare coinvolgimento nell\u2019utente. La riflessione sulle dimensioni, o livelli, dell\u2019esperienza, visceral, behavioral e reflective e i loro rapporto con l\u2019approccio estetico, pragmatico, olistico ed emotivo al design dell\u2019interazione, la definizione dell\u2019emotional, behavioral ed experience centered design hanno dimostrato come esistano modelli validi, anche se non definitivi, per analizzare il comportamento dell\u2019utente, e le modalit\ue0 con cui quest\u2019ultimo percepir\ue0 e comunicher\ue0 l\u2019esperienza che sta vivendo. L\u2019analisi del digital heritage italiano ha presentato un quadro in qualche modo positivo, che per\uf2 tradisce ancora alcune problematiche che sono il sintomo di un potenziale ancora inespresso. L\u2019analisi della promozione attraverso il web e i canali social ha messo in evidenza come le prestazioni delle istituzioni italiane siano decisamente inferiori rispetto ad altre realt\ue0 europee, nonostante diverse survey, compiute sia a livello italiano che europeo, dimostrino come gli utenti italiani utilizzino con regolarit\ue0 gli strumenti web e social, in misura anche maggiore rispetto alla media europea