Base isolator with variable stiffness and damping: design, experimental testing and modelling

Vulnerability in base isolation system of civil structures originated from passive nature of the rubber material raises the urgency of developing smart base isolation system with adaptive and controllable properties, i.e. variable stiffness and damping. To address this issue, this paper presents comprehensive investigations on a novel adaptive base isolator, including design, experimental testing and dynamic modelling. Smart rubber with field-dependent modulus and damping property is incorporated into the laminated base isolator design. Experimental testing is conducted utilising an advanced shake table facility to examine its performance under cycling loading. Results show that the adaptive base isolator possesses a stiffness increase of more than 16 times and damping ratio between 10% and 27%. With such features, it can be developed into a smart base isolation system to protect civil structures against any type of earthquake. Results also show that this device has high nonlinear hysteresis, i.e. shear stiffening behaviour. A mechanical model is thus required to describe the complex behaviour of new adaptive base isolator. A new strain stiffening element is proposed for this purpose. Comparison between the model and the experimental data verifies the fidelity and effectiveness of the proposed model

Smart Traction Control Systems for Electric Vehicles Using Acoustic Road-type Estimation

The application of traction control systems (TCS) for electric vehicles (EV) has great potential due to easy implementation of torque control with direct-drive motors. However, the control system usually requires road-tire friction and slip-ratio values, which must be estimated. While it is not possible to obtain the first one directly, the estimation of latter value requires accurate measurements of chassis and wheel velocity. In addition, existing TCS structures are often designed without considering the robustness and energy efficiency of torque control. In this work, both problems are addressed with a smart TCS design having an integrated acoustic road-type estimation (ARTE) unit. This unit enables the road-type recognition and this information is used to retrieve the correct look-up table between friction coefficient and slip-ratio. The estimation of the friction coefficient helps the system to update the necessary input torque. The ARTE unit utilizes machine learning, mapping the acoustic feature inputs to road-type as output. In this study, three existing TCS for EVs are examined with and without the integrated ARTE unit. The results show significant performance improvement with ARTE, reducing the slip ratio by 75% while saving energy via reduction of applied torque and increasing the robustness of the TCS.Comment: Accepted to be published by IEEE Trans. on Intelligent Vehicles, 22 Jan 201

Requirements of a Supportive Environment for People on the Autism Spectrum: A Human-Centered Design Story

People on the autism spectrum have a different perception of the environment than neurotypical people and often require support in various activities of daily living. Assistive technology can support those affected, but very few smart-home-like technologies exist. To support people on the autism spectrum in their autonomy and safety and to help caregivers, a smart home and interior design environment was developed. Requirements were gathered by employing a holistic human-centered design approach through interactive workshops and questionnaires to create a useful and user-friendly solution. From this process, requirements for a comprehensive solution (the SENSHOME environment) emerged. These requirements include a set of functionalities tailored to the needs of people on the autism spectrum, such as a crowd warning that informs when many people are in a certain area (for example, the entrance), an automatic light regulation system, or a daily life planner that supports task completion. Furthermore, inclusive furniture elements such as a refuge seat or a table with dividers can support wellbeing, autonomy, and safety. This paper demonstrates a consequent and considerable participatory research approach and the story from the target group and context of use through design requirements to the initial design solution of the SENSHOME environment