Search results for "Automotive engineering"

Classification and Review of Pump-Controlled Differential Cylinder Drives

2019

Pump-controlled hydraulic cylinder drives may offer improved energy efficiency, compactness, and plug-and-play installation compared to conventional valve-controlled hydraulic systems and thus have the potential of replacing conventional hydraulic systems as well as electro-mechanical alternatives. Since the late 1980s, research into how to configure the hydraulic circuit of pump-controlled cylinder drives has been ongoing, especially in terms of compensating the uneven flow requirements required by a differential cylinder. Recently, research has also focused on other aspects such as replacing a vented oil tank with a small-volume pressurized accumulator including the consequences of this i…

A Comparison Study of a Novel Self-Contained Electro-Hydraulic Cylinder versus a Conventional Valve-Controlled Actuator—Part 2: Energy Efficiency

2019

This research paper presents the second part of a comparative analysis of a novel self-contained electro-hydraulic cylinder with passive load-holding capability against a state of the art, valve-controlled hydraulic system that is typically used in load-carrying applications. After addressing the control design and motion performance in the first part of the study, the comparison is now focused on the systems&rsquo

Current fault signatures of Voltage Source Inverters in different reference frames

2016

This paper considers different current patterns used to identify the correct fault signatures in Voltage Source Inverters (VSI). At the beginning, the Authors consider the currents patterns from which a simple or a double fault can be encompassed both in the case of controllable device only or with its free wheeling companion diode. After the discussion of diagnosis algorithm suitable for electrical drives and principally based on a persistent near zero current condition current in the natural phase reference frame, the stationary reference frame is then considered as a tool to identify both the faulted phase as the device or various combination of faulted devices. On the contrary, the Auth…

Robust Composite Nonlinear Feedback Path-Following Control for Independently Actuated Autonomous Vehicles With Differential Steering

2016

This paper investigates utilizing the front-wheel differential drive-assisted steering (DDAS) to achieve the path-following control for independently actuated (IA) electric autonomous ground vehicles (AGVs), in the case of the complete failure of the active front-wheel steering system. DDAS, which is generated by the differential torque between the left and right wheels of IA electric vehicles, can be utilized to actuate the front wheels as the sole steering power when the regular steering system fails, and thus avoids dangerous consequences for AGVs. As an inherent emergency measure and an active safety control method for the steering system of electric vehicles, DDAS strategy is a valuabl…

Feasibility study of electromechanical cylinder drivetrain for offshore mechatronic systems

2017

Currently, there is an increasing focus on the environmental impact and energy consumption of the oil and gas industry. In offshore drilling equipment, electric motors tend to replace traditionally used hydraulic motors, especially in rotational motion control applications. However, force densities available from linear hydraulic actuators are still typically higher than those of electric actuators. Therefore, usually the remaining source of hydraulic power is thereby the hydraulic cylinder. This paper presents a feasibility study on the implementation of an electromechanical cylinder drivetrain on an offshore vertical pipe handling machine. The scope of this paper is to investigate the fea…

Analysis of Linear Feedback Position Control in Presence of Presliding Friction

2016

Heat Pump Induction Motor Faults Caused by Soft Starter Topology — Case Study

2021

This paper presents a case study of electrical machine faults, emerging in heat pump systems. In Nordic countries, heat pumps have been gaining popularity during the past years and have become one of the leading ways of heating in households and smaller public buildings. Although not a very complicated setup, the devices used are still prone to unexpected failures, especially if wrongly chosen, installed or maintained. The paper presents a study conducted on five real-life cases with very similar outcomes and failure modes. The setup of the systems is explained, faults are listed and presented, causes of the faults including modeling and measurement data are provided. The suggestions are gi…

Investigación clínica en 2016: artículos destacados

2017

Resumen En el ano 2016, se han publicado numerosos articulos de calidad sobre la enfermedad de Crohn (EC) y la colitis ulcerosa (CU). La importancia de la dieta o de los germenes en la enfermedad inflamatoria intestinal (EII), la repercusion de la EII en la calidad de vida, el papel de la calprotectina o la posibilidad de usar el PET en el seguimiento de la EII son algunos de los temas a destacar. El tratamiento ha sido foco de numerosos ensayos, consolidando el infliximab (sugiriendo niveles en la semana 2), el adalimumab y el golimumab, como tratamientos de primera linea, apoyando el uso de ustekinumab en EC, y dejando el metotrexato como ultimo recurso en la CU, salvo en artropatia. Por …

Manejo práctico de la intensificación del tratamiento biológico en los pacientes con enfermedad inflamatoria intestinal

2016

Resumen El tratamiento biologico con anticuerpos frente al factor de necrosis tumoral alfa (anti-TNF) ha mejorado las posibilidades terapeuticas de la enfermedad inflamatoria intestinal (EII). Estos farmacos han mostrado una elevada eficacia clinica, asociada fundamentalmente a la curacion de la mucosa intestinal y a la mejora de la calidad de vida de los pacientes. Sin embargo, un porcentaje considerable de pacientes no responden inicialmente al tratamiento o pierden la respuesta conseguida a lo largo del tiempo. Con vistas a resolver el fracaso del tratamiento anti-TNF, se han empleado varias estrategias en una actitud conocida como intensificacion del tratamiento. Estas estrategias inclu…

The best way to assess visually induced motion sickness in a fixed-base driving simulator

2017

Abstract Objective Driving simulator usage is becoming more widespread, yet many users still experience substantial motion sickness-like symptoms induced by optical flow, called visually induced motion sickness (VIMS). The Fast Motion sickness Scale (FMS) allows for continuous on-line assessment of VIMS. Using mixed models for ordinal data, this study investigated how to optimally analyze FMS data, and then used the resulting models to examine the development of symptoms over time in detail. Additionally, the study explored the impact of specific VIMS-inducing road elements. Methods Twenty-eight healthy young adults without prior simulator experience completed six courses on two days in a f…