Green vehicles include electric vehicles, natural gas vehicles, fuel cell vehicles (FCV), and vehicles running on fuel such as a biodiesel or an ethanol blend. An FCV is equipped with a cylinder valve installed in an ultra-high pressure vessel to control the hydrogen flow. For this purpose, an optimum design of the solenoid actuator is necessary to ensure reliability when driving an FCV. In this study, an electromagnetic field analysis for ensuring reliable operation of the solenoid actuator was conducted by using Maxwell V15. The electromagnetic field analysis was performed by magneto static technique, according to the distance between magnetic poles, in order to predict the attraction force. Finally, the attraction force was validated through comparison between the Maxwell results and measurement results. From the results, the error of attraction force ranged from 2.33 to 3.85 N at testing conditions.

A pilot-operated solenoid valve is used to control ultra-high pressure vessels. However, it is difficult to understand its dynamic behavior because the valve operates under ultra-high pressure conditions and the driving unit moves in a multi-step fashion in a tight hidden space. This study aims to identify the system coefficient, especially the damping coefficient, required to analyze the dynamic behavior of a solenoid driving unit. Experiments to measure the dynamic behavior of the driving unit are conducted using two laser sensors and one accelerator. The damping coefficient is estimated using Matlab Simulink, by varying the damping coefficient to match the experimental results. The obtained system coefficients are modeled as equations of motion. It is verified that the valve motion consists of two sequential movements—Phase 1 by pilot plunger and Phase 2 by main plunger, pilot plunger, and the valve initiation time is as fast as 9.9 ms. The damping coefficient of each phase is estimated 0.001 N ∙ s/mm for Phase 1, 0.004 N ∙ s/mm for Phase 2.

The aim of this work was to develop an eddy current type pressure sensor and investigate its fundamental characteristics affected by the mechanical and electrical design parameters of sensor. The sensor has two key components, i.e., diaphragm and coil. On the condition that the outer diameter of sensor is 10 mm, two key parts should be designed so as to keep a good linearity and sensitivity. Experiments showed that aluminum is the best target material for eddy current detection. A round-grooved diaphragm is suggested in order to measure more precisely its deflection caused by applied pressures. The design parameters of a round-grooved diaphragm can be selected depending on the measuring requirements. A developed pressure sensor with diaphragm of t = 0.2 mm and w = 1.05 mm was verified to measure pressure up to 10 MPa with very good linearity and errors of less than 0.16%.

Changing a time-varying magnetic field induces an electromotive force (EMF) in non-magnetic conductive materials, resulting in an eddy current across the conductor. Thus, electromagnetic damping can be used as viscous damping. This study theoretically and experimentally investigates the electromagnetic damping characteristics of a bobbin-wounded coil with an attached cantilever beam floating over a permanent magnet; the beam is balanced by electromagnetic force compensation (EMFC) instead of applied weight. System identification is carried out for the mass (m), damping coefficient (c), and spring constant (k) values. The presence of a back EMF seen in either conductive or non-conductive material responses in the experiments includes the step input and corresponding output responses to measure the electromagnetic damping force with and without a voice-coil actuator (VCA). The results were validated using bobbins of conductive (aluminum) and non-conductive (plastic) materials. The experimental results for the conductive material show that the electromagnetic damping force is 10 times greater than that of the non-conductive material; the opposite was true in the case without a VCA, where the force was almost zero for the non-conductive material. In conclusion, conductivity is directly related to the electromagnetic damping force, which affects the performance of a VCA.

Background: Steering a catheter tip to a defective spot on a lung during fibrin glue application under pleurography (FGAP) constitutes a very challenging task. Accurate control of tip position/slope of steerable catheters is critical for providing glue to air-leaking defects on lung during FGAP. Steerable catheters arc composed of multiple segments with different flexural rigidities and experience nonlinear deformation. Therefore, predicting tip position with accuracy is difficult. The purpose of this paper is to present a novel method that can accurately control the tip of the catheter, and thus enhance its target accessibility. Methods: The tip position of a deflected steerable catheter can be accurately predicted using a simulation tool depicting the curvature of a bent catheter based on a mechanics of materials analysis. The proposed method utilizes the simulation tool to enhance the target accessibility of the catheter's tip. This assists medical doctors to not only select the optimal catheter prior to operation, but also to steer the catheter to the defects effectively. Simulation reliability is tested by performing a catheter deflection experiment and measuring the tip position. Results: The simulation result accurately predicts the location of the catheter tip with an error of less than 5 mm to the experimental results. Conclusions: Controlling pull-wire tensions and overhang lengths based on simulation results substantially improves the target accessibility of the catheter tip.