Search results for "energy [neutrino]"
showing 10 items of 2387 documents
Performance Improvement of a Hydraulic Active/Passive Heave Compensation Winch Using Semi Secondary Motor Control: Experimental and Numerical Verific…
2020
In this paper, a newly developed controller for active heave compensated offshore cranes is compared with state-of-the-art control methods. The comparison is divided into a numerical part on stability margins as well as operational windows and an experimental validation of the expected performance improvement based on a full-scale testing on site with a crane rated to 250 metric tons. Such a crane represents the typical target for the new control method using a combination of active and passive hydraulic actuation on the main winch. The active hydraulic actuation is a hydrostatic transmission with variable-displacement pumps and variable-displacement motors. The new controller employs feedf…
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
A Novel Solution for the Elimination of Mode Switching in Pump-Controlled Single-Rod Cylinders
2020
This paper concerns the stability issue of pump-controlled single-rod cylinders, known as mode switching. First, a review of the topic is provided. Thereafter, the most recently proposed solution for the elimination of mode switching is investigated and shown to result in unstable behavior under certain operating conditions. A theoretical analysis is provided demonstrating the underlying mechanisms of this behavior. Based on the analysis, a novel control strategy is proposed and investigated numerically. Proper operation and stability are demonstrated for a wide range of operating conditions, including situations under which the most recently proposed solution results in unstable behavior a…
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…
Dynamic Response of a Rigital Displacement Motor Operating with Various Displacement Strategies
2019
Digital displacement technology has the potential of revolutionizing the performance of hydraulic piston pumps and motors. Instead of connecting each cylinder chamber to high and low pressure in conjunction with the shaft position, two electrically-controlled on/off valves are connected to each chamber. This allows for individual cylinder chamber control. Variable displacement can be achieved by using different displacement strategies, like for example the full stroke, partial stroke, or sequential partial stroke displacement strategy. Each displacement strategy has its transient and steady-state characteristics. This paper provides a detailed simulation analysis of the transient and steady…
A port-Hamiltonian Fluid-Structure Interaction Model for the Vocal folds ⁎ ⁎This work was supported by CONICYT-PFCHA/2017-21170472, and AC3E CONICYT-…
2018
Abstract Fluid-structure interaction models are of special interest for studying the energy transfer between the moving fluid and the mechanical structure in contact. The vocal folds are an example of a fluid-structure system, where the mechanical structure is usually modeled as a mass-spring-damper system. In particular, the estimation of the collision forces of the vocal folds is of high interest in the diagnosis of phonotraumatic voice pathologies. In this context, the port-Hamiltonian modeling framework focuses on the energy flux in the model and the interacting forces. In this paper, we develop a port-Hamiltonian fluid-structure interaction model based on the interconnection methodolog…
Friction stir extrusion to recycle aluminum alloys scraps: Energy efficiency characterization
2019
Abstract Solid state recycling refers to a group of processes allowing direct recycling of metals scraps into semi-finished product. Their main advantage lies in avoiding the molten state of the material which badly affects the environmental performance of the conventional (remelting based) recycling routes. It is expected that such process category would lower the environmental performance of metals recycling. In this paper, the friction stir extrusion process for aluminum alloy AA 2050 wire production is analyzed under the primary energy demand perspective. The process electrical energy demand is quantified with varying process parameters. An empirical modelling approach was applied and a…
Uncovering Technological and Environmental Potentials of Aluminum Alloy Scraps Recycling Through Friction Stir Consolidation
2020
Conventional metal chips recycling processes are energy-intensive with low efficiency and permanent material losses during re-melting. Solid state recycling allows direct recycling of metal scraps into semi-finished products. It is expected that this process category would lower the environmental performance of metals recycling. Friction Stir Consolidation is a new solid-state technique taking advantage of friction heat generation and severe plastic deformation to consolidate chips into billets. In this research, the feasibility of Friction Stir Consolidation as aluminum chips recycling process is analyzed. Specifically, an experimental campaign has been carried out with varying main proces…
Microstructural, mechanical and energy demand characterization of alternative WAAM techniques for Al-alloy parts production
2020
Abstract Additive manufacturing (AM) processes are gathering momentum as an alternative to conventional manufacturing processes. A research effort is being made worldwide to identify the most promising AM approaches. Within this category, wire arc additive manufacturing (WAAM) is among the most interesting, especially when large parts must be manufactured. In this paper, two different WAAM deposition techniques suitable for the deposition of Aluminum alloys, Cold Metal Transfer (CMT) and CMT mix drive, are analyzed and compared. With the aim of obtaining a clear picture concerning the two different techniques, microstructural analyses, mechanical property evaluation and electrical energy de…