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Through and comprehensive tests are necessary to ensure complete stability and reliability of AUV, due to the high risk and consumption of in field testing, onshore testing technology for AUV is proposed. Rudder load simulator plays an important role in the onshore testing of AUV. In this paper, the design and development of a rudder load simulator was discussed. Rudder load calculation method during...
Recently, coastal city and facilities had many damages by abnormally high waves with climate change. Especially, breakwater systems based on a caisson-type harm damages in Korea because they are located in the outside port. In order to reduce theses damages, new type breakwater systems using interlocking caisson are researched. Generally, caissons of breakwater system were constructed on crushed rock...
This paper deals with the problem of neural network delay control for an idealized offshore platform system. Two neural networks (feed-forward neural network and nonlinear autoregressive neural network) delay controllers are proposed to the vibration control of the offshore platform under external wave force. It is shown through simulation results that the designed neural network delay controllers...
As the air bearing flying height (a few nanometer levels) and the deformation of suspensions (micro-or millimeter level) run at two different scales, a dual-scale model for head disk interface (HDIs) has been proposed to analyze the unloading behavior of a subambient pressure slider. With the scheme developed, the unloading process can be simulated efficiently. The nonlinear vibrations of the air...
Precise force detection is required to realize precise force control, and a lot of research have been conducted for precise and robust force estimation. Based on the industrial trends that the number of load-side encoders is increasing in various industrial fields, a force observer using load-side encoder information has already been proposed to avoid the estimation performance deterioration in the...
In this paper, a nonlinear dynamic model is developed considering backlash, time-varying mesh stiffness (TVMS), and sliding friction. Friction is firstly introduced to a spur gear pair nonlinear dynamic model under random load. Transient characteristics of the spur gear transmission system are studied. The results show that random load causes longer duration of transient state and stronger vibration...
Heavy lift crane vessels play an important role in offshore installations. Previous studies have shown that position control systems for these vessels can cause unstable positioning behavior during offshore construction assignments under specific conditions, e.g., change of environmental loads. Some control methods, such as crane force feedforward to the controller or the estimator, have been developed...
High speed repulsion mechanism is the key component of Hybrid DC circuit breaker, whose properties and reliability directly determine whether the fault short-circuit current can be quickly broken off. The driving force, produced by the eddy current effect, reach tens of kilo Newton in 100μs, which means the huge impact on motion component. Due to its characteristics, it is necessary to check the strength...
This paper presents an integrated articulated steering vehicle's (ASV) dynamics model, which provides a simulation platform for research on path tracking control of ASV. The active speed limiting control is designed according to the sideslip constraints to improve the lateral stability of the vehicle during path tracking. The weighted PID controller is applied to control the steering torque based...
A large interest has recently been given to global chassis control. This requires a tire model adapted to control synthesis that can represent combined slip. In this paper, a new suitable tire model for vehicle coupled operations control is proposed. The existing models are either too simple to represent coupled behaviors or too complex to allow control synthesis. This new tire model takes benefits...
This paper investigates curve-fitting methods to explore uncertainty quantification approaches for demand fluctuations in a power grid. Specifically, we use data sets from the Pennsylvania-New Jersey-Maryland (PJM) Interconnection, where we employ two stages of fitting. In stage one, a trigonometric based fit for historical data sets is carried out. In stage two, load forecasting for day-ahead market...
The shape of a compressed solder bump under mechanical load stemming from the weight of an IC or IC package has an important influence on the contact angles and the stresses that results from thermal cycling. In this work an expression is derived that provides a more accurate description of this shape. The shape of the small solder bump is dominated by surface tension and the shape of the unloaded...
The objectives of this project are to determine the behaviour to withstand a load that is gradually increased in one position such as standing on one leg and finding the methodology in conducting this experiment. The observation is mainly focused on the UHMWPE acetabular cup. The prosthesis was made by the assembly of Titanium grade-2 femoral stem, SS316L femoral ball, and UHMWPE acetabular cup. The...
This paper investigates methods of magnet mass reduction in linear flux switching permanent magnet (LFSPM) machines by introducing tapered consequent poles. Based on the finite element analysis (FEA) three different models are designed, investigated and compared. The obtained results indicate that by adopting the proposed tapered ferromagnetic poles a considerable saving of material cost and weight...
In this paper a novel E-core Linear Variable Reluctance Vernier Hybrid Permanent Magnet (LVR-VHPM) machine with inherent magnetic gearing is proposed for use in the long stroke application of a wave energy converter. The proposed topology is a combination of a doubly salient flux reversal machine, a consequent pole machine and a surface mounted Halbach array Permanent Magnet (PM) machine. The stator...
The paper presents the failure mode of high-power light emitting diodes (LEDs) under mechanical pressure and verifies the bonding wire as the weakest structure of LEDs. Different lens radiuses and heights are studied to demonstrate the influence of lens parameters on the mechanical strength of LEDs. The experimental results have demonstrated that a LED device has a higher failure force when the lens...
The Electric Motor Train Units (EMU) load is the main load of the power traction system for high-speed railway, so the accuracy of load characteristic description has an important influence on establishing traction load model. This article designed the logical control strategy for traction drive system and set up a complete digital simulation model of the traction drive system for CRH2 EMU, and then...
A novel parametric model of the stiifened shell is developed by Python language with Abaqus in this paper. As an effective analysis method in the optimal design, explicit finite element method (FEM) is used to design and optimize the skin thickness and stiffener size of Stiffened Shells. The optimization objectives and constraints are mainly the minimum mass subject to the structural performance and...
Based on the working principle of the electrohydraulic proportional control system of the working device of the demolition robot, the co-simulation model of the system is established by means of ADAMS and MATLAB. The study of the dynamic characteristics of the system was done, with applying traditional PID control strategy and sliding mode variable structure control respectively, considering the change...
Warm sheet hydroforming process has being investigated in recent years with its high formability feature. Warm hydromechanical deep drawing (WHDD) which is a type of the warm sheet hydroforming process is important for deeper parts. To determine the formability of the WHDD process the most convenient tool is Limiting Drawing Ratio (LDR). But determination of the LDR accurately needs using of the most...
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