Predictive functional control for unstable first-order dynamic systems

Predictive functional control (PFC) has emerged as a popular industrial choice owing to its simplicity and cost-effectiveness. Nevertheless, its efficacy diminishes when dealing with challenging dynamics because of prediction mismatch in such scenarios. This paper presents a proposal for reducing prediction mismatch and thus improving behaviour for simple unstable processes; a two-stage design methodology pre-stabilises predictions via proportional compensation before introducing the PFC component. It is demonstrated that pre-stabilisation reduces the dependency of the closed-loop pole on the coincidence point and also improves robustness to uncertainty. Simulation results verify the improved performance as compared to conventional PFC

A first course in feedback, dynamics and control: findings from an online pilot survey for the IFAC community

Undergraduate students in many engineering programs around the world take only one control course. The IFAC Educational Committee has developed and piloted to a limited audience a comprehensive survey for the topics to be included in such course. This issue is relevant to both academia and industry. The paper discusses the initial findings related to the design of the survey as well as the responses of the participants. The findings will be used to refine the survey and distribute it in the near future to the global control community

Respiratory simulator for robotic respiratory tract treatments

Robotic healthcare is a growing and multi-faceted field where robots help perform surgery, remotely provide care to patients, aid in supplying various physical therapies and further medical research. Robotic simulators of human physiology provide a powerful platform to advance the development of novel treatments, prostheses and therapies. This study focuses on the design, building, testing and characterisation of a novel simulator of the human respiratory system. The comparison between healthy subjects breathing and coughing physiological values and the values achieved utilising our novel bioinspired respiratory simulator shows that the latter is able to reproduce peak flow rates and volumes

A new paradigm for Predictive Functional Control to enable more consistent tuning

This paper presents two significant contributions to the understanding of Predictive Functional Control (PFC). First, it gives novel insights and explanations into a poorly understood issue, that is the weak link between PFC tuning parameters and the resulting closed-loop behaviour. This new understanding is then exploited to proposed a modification to the existing PFC algorithm which creates a much stronger tuning link while retaining the critical properties of elementary coding and understanding. The efficacy of the proposal is demonstrated on several numerical examples

NeatSkin:A Discrete Impedance Tomography Skin Sensor

In this paper we present NeatSkin, a novel artificial skin sensor based on electrical impedance tomography. The key feature is a discrete network of fluidic channels which is used to infer the location of touch. Change in resistance of the conductive fluid within these channels during deformation is used to construct sensitivity maps. We present a method to simulate touch using this unique network-based, low output dimensionality approach. The efficacy is demonstrated by fabricating a NeatSkin sensor. This paves the way for the development of more complex channel networks and a higher resolution soft skin sensor with potential applications in soft robotics, wearable devices and safe human-robot interaction.</p

Modelling and analysis of pH responsive hydrogels for the development of biomimetic photo-actuating structures

ABSTRACTPhoto-actuating structures inspired by the chemical sensing and signal transmission observed in sun-tracking leaves have recently been proposed by Dicker et al. The proposed light tracking structures are complex, multicomponent material systems, principally composed of a reversible photoacid or base, combined with a pH responsive hydrogel actuator. New modelling and characterization approaches for pH responsive hydrogels are presented in order to facilitate the development of the proposed structures. The model employs Donnan equilibrium for the prediction of hydrogel swelling in systems where the pH change is a variable resulting from the equilibrium interaction of all free and fixed (hydrogel) species. The model allows for the fast analysis of a variety of combinations of material parameters, allowing for the design space for the proposed photo-actuating structures to be quickly established. In addition, experimental examination of the swelling of a polyether-based polyurethane and poly(acrylic acid) interpenetrating network hydrogel is presented. The experiment involves simultaneously performing a titration of the hydrogel, and undertaking digital image correlation (DIC) to determine the hydrogel’s state of swelling. DIC allows for the recording of the hydrogel’s state of swelling with previously unattained levels of resolution. Experimental results provide both model material properties, and a means for model validation.</jats:p