Tilt Mechanism Research Articles

Technical Feasibility of Flat Plate Collector Water Heating System with Auto Tilting Mechanism

Solar energy is the basic source of all the energy needs of the human kind. Solar energy, in its various forms is used by human civilization for fulfilling its needs. Water heating system is one of them. Conventionally, Flat Plate Collector (FPC) solar water heating system was used for this purpose. However, with technological development, new and more advanced systems, which are much more efficient and cost effective, replaced the FPC market. The developed pilot scale system in the current paper tries to evaluate the performance of the FPC by inclusion of an auto tilting mechanism for utilizing maximum incident solar radiation throughout the day. Changes in the temperature with respect to time, and comparison of the temperature variations of the tilting panel and a fixed panel were recorded, and further, a suitable mathematical correlation was developed for prediction of theoretical temperatures.

Adaptive tilting angles to achieve high‐precision scanning of a dual probes AFM

AbstractAtomic force microscopy (AFM) is a powerful measurement tool, widely used in microfabricated structure inspection. However, since it is typical that the fixed tilting angle of a probe is employed in traditional AFM, the corner and sidewall image of the scanned sample would be distorted. To overcome the problem, a so‐called adaptive tilting angle algorithm (ATAA) applied to a self‐designed dual‐probe AFM system is presented to achieve on‐line sidewall estimation during scanning of general samples. Through the use of the proposed ATAA, the tilting angles of dual probes for each scan line can be self‐adjusted to the optimal ones. Overall, a probe tilt mechanism is designed, which allows the AFM system to change the tilting angles of the probes during the scanning process such that the dual‐probe structure AFM can acquire a complete high precision image with just a single scan. The experimental results show the performance of sidewall measurement and the high‐precision image obtained by the proposed method.

Road Bank Angle Estimation for Three Wheel Tilting Vehicle Using Multi Model Estimator

In recent years, the need for micro-mobility, especially three-wheel vehicles, is increasing to address pollution and traffic congestion problems. With regard to the development of tilting vehicles, the precise tilt angle is important information in the tilting mechanism. Since the road environment affects the vehicle tilt angle, the road bank and hill angle have to be estimated to optimize the tilt control system. Furthermore, a new tilt mechanism is required due to the energy consumption of the previous active tilting mechanism. This paper introduces the road state observer. In this paper, the observer that combines a kinematic model with a dynamic model of a three wheel vehicle is proposed. The dynamic model has four states, including lateral velocity, yaw rate, tilt angle, and tilt angle ratio. Similarly, kinematic model has two states, including roll and pitch angles. It is assumed that the data set received from the six-dimensional inertial measurement unit including the vehicle acceleration and angular velocity of all axes is available. To verify the proposed algorithm, simulation verification using Carsim ADAMS and Matlab&Simulink is performed and a discussion of the result is provided. In addition, this paper proposes a semi-active tilt system.

Cascaded Mirror Array: design and demonstration of low-cost light-weight digital scanning

A new digital scanning approach is proposed and its feasibility is demonstrated. The Cascaded Mirror Array applies an array of reflectors, with each reflector movable between discretized angular positions controlled by digitized electrical signals, to process a light beam by cascaded reflections to generate desired deflections of a light beam. An Uneven-Leg Tilting mechanism was devised to provide a very significant mechanical reduction ratio so that it can be used to generate very small tilt angles by comparatively large, finite displacements that can be easily created. A 4-bit 1D scanner prototype, built by simple non-MEMS methods, demonstrated point-to-point scanning at 0.0125° resolution from 1 to several hundred Hz. Studies based on finite element simulations suggest that by increasing electromagnetic driving force and reducing the size and mass of the prototype construction operating frequency up to several thousand Hz can be achieved. The new approach has the potential of making low-cost light-weight robust high speed scanners.

MODELLING AND CONTROL OF H-SHAPED RACING QUADCOPTER WITH TILTING PROPELLERS

Traditional quadcopter suffers terribly from its underactuation which implies the coupling between the rotational and the translational motion. In this paper, we present a quadcopter with dynamic rotor tilting capability in which the four propellers are allowed to tilt together around their arm axis. The proposed model provides leveled forward/backward horizontal motion and therefore, ensures a correct view of the onboard camera, and increases the vehicle speed by reducing the air drag. The rotor tilt mechanism also provides an instant high speed in the forward or reverse direction and offers a quick and solid air brake to restrain that fast moving speed. The nonlinear dynamical model for the quadcopter under consideration is derived using Newton-Euler formalization. A control strategy is then proposed aimed to control the altitude, attitude, and the forward speed of the obtained model. Finally, a numerical simulation is used to integrate the system model with the controller and to test the system performance. Simulation results are reported to demonstrate the advantages of the proposed novel configuration.

Study of parameters of elements of a felling head for lifting and moving trees for the purpose of clearing agricultural lands and agroforestry

The purpose of this article is the theoretical justification of parameters of the felling head elements and experimental studies of its the work technique on the basis of the tractor of the drawbar category 0.6-1.4. The essence of theoretical study is to determine parameters of the mounted felling head for cutting and vertical holding of a tree of a diameter of 10 to 22 cm, taking into account the optimal working zone of the tilt mechanism. Experimental study was carried out on a prototype of a one-grip felling machine (OGFM) (based on the T-25 tractor) with the mounted felling head. In the process of carrying out field studies, technological performance parameters of the OGFM for low-capacity logging and the pressure in the hydraulic system of the felling head were studied under various operating conditions.

Design of a Large-Stroke Bistable Mechanism for the Application in Constant-Force Micropositioning Stage

To overcome the constraint of conventional tilted beam-based bistable mechanism, this paper proposes a novel type of bistable structure based on tilted-angle compound parallelogram flexure to achieve a larger stroke of negative stiffness region while maintaining a compact physical size. As an application of the presented bistable mechanism, a flexure constant-force micropositioning stage is designed to deliver a large stroke. The constant force output is obtained by combining a bistable flexure mechanism with a positive-stiffness flexure mechanism. To facilitate the parametric design of the flexure mechanism, analytical models are derived to quantify the stage performance. The models are verified by carrying out nonlinear finite-element analysis (FEA). A metal prototype is fabricated for experimental study. Results demonstrate the effectiveness of the proposed ideas for a long-stroke, constant-force compliant mechanism dedicated to precision micropositioning applications. Experimental results also show the appearance of two-stage constant force due to the manufacturing errors of the bistable beams.

Effect of Head Tilt and Ocular Compensatory Mechanisms on Retinal Nerve Fiber Layer Measurements by Cirrus Spectral Domain and Spectralis Optical Coherence Tomography in Normal Subjects.

To determine the effect of head tilt and ocular compensatory mechanisms on retinal nerve fiber layer (RNFL) thickness measurements using the Cirrus and Spectralis spectral-domain optical coherence tomography (OCT) in healthy eyes. Our secondary objective was to assess the visual influence on ocular compensatory mechanisms during head tilt. This is a prospective, observational study. A single randomly selected eye was scanned undilated in 3 positions (baseline, right, and left tilt) using both machines. In addition, patching was also done for the contralateral eye during head tilt and RNFL measurements repeated. The paired t test was used to analyze effect on RNFL thickness. One-way repeated-measures analysis of variance was used to compare differences in RNFL measurements. In Cirrus OCT RNFL analysis, ipsilateral head tilt resulted in superior thinning and temporal thickening, whereas contralateral head tilt resulted in inferior thinning, nasal thickening, as well as temporal thickening (all P<0.05). Head tilt did not cause any significant change in RNFL thickness with Spectralis OCT (P>0.05). Patching the contralateral eye also did not alter Cirrus RNFL measurement errors due to head tilt. Head tilt can affect the measurement of the RNFL thickness in Cirrus OCT, and ocular compensatory mechanisms were not sufficient to prevent this. In contrast, Spectralis OCT RNFL thickness measurements were not affected by head tilt. Patching the contralateral eye during head tilt in Cirrus OCT also did not affect RNFL variability. The visual influence on ocular compensatory mechanisms during head tilt appears insignificant.

Simulation of combined body tilt system of high-speed railway rolling stock

The actual problem of creating a high-speed railway rolling stock with a combined electromechanical and pneumatic body tilt system is considered. Using the proposed simulation model created in the MATLAB environment, simulation of the rolling stock body tilt while passing a curved track section is carried out. To determine the parameters of the elements of electromechanical and pneumatic drive units, information is necessary about the electrophysical processes, occurring in the tilt system and determining the input parameters for the design of the considered tilt system. The dynamic performance of components of the proposed mechanism is identified, which allows giving practical advice on the choice of parameters of semiconductor converter elements, pneumatic and electromechanical devices of the combined tilt system, and also determining the forces acting in the tilt mechanism elements. Based on these dependencies, it is possible to choose the element base of the semiconductor converter (types of keys and diodes), parameters and types of cylinders of air springs, as well as to determine the load of the elements of the overbogie structure of the rolling stock. The results can be used in the development and design of high-speed railway rolling stock without substantial reconstruction of the existing transport infrastructure.

Internet cognitive failure affects learning progress as mediated by cognitive anxiety and flow while playing a Chinese antonym synonym game with interacting verbal–analytical and motor-control

According to the person-artifact-task model, the process of gameplay can trigger a range of emotional responses and wide variation in students' behaviors, consequently leading to varying learning outcomes. How internet cognitive failure (ICF) can affect a game player's cognitive anxiety and flow experience, and how this interplays with learning progress was explored in this study. Ninth grade students participated in playing “Running Chinese Zodiac”, a Chinese antonyms and synonyms App game, which combines interactions of verbal–analytical aspects with motor-control. The motor-control aspect required players to control a tilt mechanism by tilting the smartphone left or right to select the correct answer. Data from 149 students were collected and subjected to confirmatory factor analysis and structural equation modeling. The results revealed that ICF was positively correlated to cognitive anxiety, but it was negatively correlated to flow experience. Cognitive anxiety was negatively correlated to flow experience and learning progress; while flow experience was found to be positively correlated to learning progress. The results implied that a game with verbal–analytical and motor-control would be useful to students with a low level of ICF to learn Chinese synonyms and antonyms.

Вдосконалення системи нахилу кузова для швидкісних поїздів з силовим приводом на базі лінійного двигуна

The short analysis of the power drives various types that used at high-speed trains tilting system are provided. The improvement ways for tilting system at the part of the kinematic scheme and power drive are defined. The improved tilting mechanisms kinematic scheme that allows to substantially reduce a size of necessary effort for car body tilt at the set corner is offered. The tilt mechanism’s calculation chart and corresponded to it mathematical model that based at the static equilibrium system equalizations for tilt system’s load characteristic receipt are used. The facilitated construction reversible linear motor with linear form hauling characteristic are got on the base of linear electromechanics converter’s electrophisics and geometrics parameters at it working properties influence laws. The bridge power supplyscheme for linear motors that provides its synchronously work and so allows to realize active system of the car body position management that influence on traveler comfort is developed. or; kinematic scheme; load characteristic

Tilted wheel satellite attitude control with air-bearing table experimental results

Gyroscopic actuators for satellite control have attracted significant research interest over the years, but their viability for the control of small satellites has only recently started to become clear. Research on variable speed gyroscopic actuators has long been focused on single gimbal actuators; double gimbal actuators typically operate at constant wheel spin rate and allow tilt angle ranges far larger than the ranges needed to operate most satellite missions. This research examines a tilted wheel, a newly proposed type of inertial actuator that can generate torques in all three principal axes of a rigid satellite using a spinning wheel and a double tilt mechanism. The tilt mechanism tilts the angular momentum vector about two axes providing two degree of freedom control, while variation of the wheel speed provides the third. The equations of motion of the system lead to a singularity-free system during nominal operation avoiding the need for complex steering logic. This paper describes the hardware design of the tilted wheel and the experimental setup behind both standalone and spherical air-bearing tables used to test it. Experimental results from the air bearing table are provided with the results depicting the high performance capabilities of the proposed actuator in torque generation.

고해상도 영상 획득을 위한 틸트 메커니즘 적용 기법

고해상도 영상 획득을 위한 틸트 메커니즘 적용 기법

Design and Fabrication of a Scaled-Down Unmanned Quad-Tilt-Prop Personal Air Vehicle

AbstractThis paper describes the design, fabrication, and test of a scaled-down unmanned personal air vehicle (PAV) with dual mode drive and flight capabilities. Considerations of the operational requirements of such a vehicle led to the concept of a quad-tilt-prop platform that has nacelle tilt capability with a multiple rotor configuration. Motors for both propeller propulsion and the driving mechanism were integrated into a single nacelle, and they were then implemented with a nacelle tilt mechanism for conversion between the drive and flight modes. The primary design parameters were examined through the conceptual design process, as follows: (1) overall dimensions, (2) empty weight, (3) propeller diameter, and (4) propulsion motor were determined based on design requirements. Functional tests were then performed, with test platforms designated for each development step. Comprehensive drive and flight tests demonstrated the operational capabilities of the finalized prototype. The fabricated vehicle has...

An unusual stacking transformation in liquid-crystalline columnar assemblies of clicked molecular propellers with tunable light emissions.

The columnar liquid-crystalline (LC) and fluorescence properties of three-dimensional molecular propellers based on tetraphenylethylene is reported. X-ray scattering studies reveal an unusual transition from a rectangular (Colrec ) to a hexagonal columnar (Colhex ) phase. In contrast to second-order intercolumnar transitions based on a common tilt mechanism, the transition is first order and involves an unprecedented zigzag stacking of aromatic propellers in the Colrec phase. A sudden change in emission color from sky blue to green occurs rapidly and reversibly at this transition, which is due to the planarization of the propeller mesogen.

Bounded gain-scheduled LQR satellite control using a tilted wheel

Generation of control torque for highly agile satellite missions is generally achieved with momentum exchange devices, such as reaction wheels and control moment gyros (CMGs) with high slew maneuverability. However, the generation of a high control torque from the respective actuators requires high power and thus a large mass. The work presented here proposes a novel type of control actuator that generates torques in all three principal axes of a rigid satellite using only a spinning wheel and a simple tilt mechanism. This newly proposed actuator has several distinct advantages including less mass and more simplicity than a conventional CMG and no singularities being experienced during nominal wheel operation. A new high performance bounded (HPB) linear quadratic regulator (LQR) control law has been presented that extends classical LQR by providing faster settling times, gain-scheduling the control input weightings to optimize its performance, and has much quicker computation times than classical LQR. This work derives a fundamental mathematical model of the actuator and demonstrates feasibility by providing three degree of freedom high fidelity simulations for the actuator using both classical LQR and HPB LQR.

Analyzing the Technical Evolutionary Paths of Converter Tilting Mechanism and Forecasting the Further Development Tendency

Developments of products and technologies always follow certain objective law and the same objective law can be applied in different technical fields. the innovation processes of any products follow a law, the development of all technical innovation is toward maximum function. By applying some technical evolution paths, this paper analyses the technical development process of Converter Tilting Machines and forecasts the future development. The evolutionary paths of converter tilting mechanism has been analyzed by using TRIZ Theory, and, the development of Converter Tilting Machine has been forecasted. According to the path toward flexibility, we can forecast that Converter Tilting Machine can be driven by Filed force.

쿼드 틸트 프롭형 PAV 무인 축소모델 개념설계 및 개발시험

This paper describes the conceptual design and development test procedure of a unmanned scaled-down personal air vehicle(PAV) with drive and flight dual mode capability. Trade studies on operational requirements led to the suggestion of a quad tilt prop platform which has nacelle tilt capability with multi rotor configuration. Motors for propeller propulsion and driving mechanism were integrated into a single nacelle, then they were implemented by nacelle tilt mechanism for conversion between the drive and the flight modes. Primary design parameters and initial specifications were confirmed through conceptual design, then functional tests were performed with the test platforms for the drive and the flight modes.

A modelling framework for marine structure foundations with example application to vertical breakwater seaward tilt mechanism under breaking wave loads

A theoretical and numerical framework to model the foundation of marine structures is presented. The theoretical framework includes two main components: (i) a mathematical model to properly represent soil skeleton–pore fluids interaction based on the Generalized Biot formulation, (ii) an advanced constitutive model to reproduce the nonlinear soil behavior based on the Generalized Plasticity framework. Apart from these two main components, suitable boundary conditions are of paramount importance. The proposed theoretical framework includes: (i) hydraulic boundary conditions to simulate the interaction between waves, sea bed and maritime structures, (ii) soil–structure interaction conditions to reproduce accurately the principal loads transmitted to the foundation, and (iii) radiation boundary conditions to make the computational domain finite. The finite element method is adopted in order to achieve accurate and robust approximate solutions of the governing equations. The proposed theoretical and numerical framework is applied to the analysis of the seaward tilt mechanism induced by the action of breaking waves over a vertical breakwater. The results numerically attained are in agreement with the main conclusions drawn from the literature associated with this failure mechanism.

An animal PET scanner using flat-panel position-sensitive PMTs

To design, build, and evaluate an animal PET scanner, which can be used with non-human primates under conscious condition, incorporating flat-panel position-sensitive photomultiplier tubes (PS-PMTs). The system contains 30 detector modules, each having two PS-PMTs and 16×18 lutetium–yttrium oxyortho-silicate scintillation crystal arrays. The system has 17,280 crystals (480 per ring) arranged in 36 rings, with a diameter of 508 mm and axial extent of 108 mm. The gantry tilt mechanism enables PET studies to be performed on a monkey in the sitting position. Data can be acquired in either the 2D or 3D mode, with the slice collimators being retracted in the 3D mode. At the center of the field-of-view, radial resolution is 2.7 mm full width at half maximum (FWHM) and tangential resolution is 2.4 mm FWHM, while axial resolution is 2.5 mm FWHM for direct slices and 2.7 mm FWHM for cross slices. Scatter fraction, count rate capability, and sensitivity were evaluated using a cylindrical phantom 10 cm in diameter. The noise equivalent count rate in the 3D mode is equivalent to that in the 2D mode at a three times higher radioactivity level. Total system sensitivity is 1.3 kcps/(kBq/mL) in 2D mode and 7.4 kcps/(kBq/mL) in the 3D mode. Animal studies with a monkey were performed to evaluate the imaging capabilities of the scanner. The new PET scanner will be a useful research tool with non-human primates for pre-clinical drug development.