Tilt Movement Research Articles

The Correlation Model of Head Roll and Lateral Acceleration during Curve Driving via Hammerstein-Wiener

Generally, passengers are more prone to Motion Sickness (MS) than the drivers. The difference of their severity level of MS is due to their different head movement towards the direction of the lateral acceleration. During cornering, the passengers tend to tilt their heads according to the direction, while the drivers tends to tilt their head opposite to the direction. Based on this fact, the passengers are able to reduce their MS level if they can imitate the driver’s head movement or lessen their head tilt angle towards the direction of the lateral acceleration. However, it is easier to design MS mitigation method based on the head tilt movement strategy if the mathematical expression of their head behaviour is known beforehand. On way to derive the mathematical expression is by modelling the relationship between the occupant’s head tilt movements and the vehicle’s lateral acceleration during curve driving. Therefore, this study proposed the usage of Hammerstein-Wiener (H-W) method for the modelling purpose. Experiment is set up to obtain the naturalistic data for the modelling process. The modelling process is carried out by varying the input output nonlinearities estimators. The results show that the estimated output responses from the H-W models are similar with the real responses taken from the experiment.The derived models for both passenger and driver have 68.88% and 66.32% of Best Fit (BF) percentages. With further study, the passenger’s and driver’s models which are developed by the proposed H-W modelling strategy are expected to contribute in MS minimisation studies.

Monitoring and analysis of mining 3D time-series deformation based on multi-track SAR data

ABSTRACT Accurate monitoring of the developing process of a surface subsidence basin is the basis of building damage assessment and surface deformation prediction. In this paper, the Synthetic Aperture Radar (SAR) data of three different imaging geometries, TerraSAR, Radarsat-2, and Sentinel-1A, were exploited. Firstly, two-dimensional (2D) time-series deformation of the surface subsidence basin caused by 15,235 working face mining was obtained based on Multidimensional Small Baseline Subset (MSBAS) technology from 19 December 2015 to 5 March 2016. By comparing vertical deformation with levelling data, it is shown that the root-mean-square error of vertical deformation is 3.2 mm and the standard deviation is 1.9 mm when the ascending-descending track SAR data is available. Otherwise, the root-mean-square error of vertical deformation is 18.1 mm and the standard deviation is 11.6 mm. Because of the low precision of the north–south horizontal movement monitored by the SAR sensor, the vertical deformation acquired by MSBAS technology and the rules of the mining subsidence (horizontal movement is proportional to tilt) were combined to obtain the north–south horizontal movement which was proven to be reliable by comparing the 2D time-series deformation obtained by MSBAS technology. Then, the deformation of the railway in the surface subsidence basin was analysed based on the three-dimensional (3D) time-series deformation. The results show that the subsidence, tilt, and horizontal movement strongly influence the railway in the monitoring period, but will not affect the normal traffic. This experiment lays a technical foundation for preventing the occurrence of mining disasters and verifies the ability to monitor the deformation of buildings and structures by interferometry synthetic aperture radar technology.

Características das Frentes Frias Causadoras de Chuvas Intensas no Leste de Santa Catarina

Resumo O presente trabalho analisa as características principais das frentes frias causadoras de chuvas intensas no litoral do Estado de Santa Catarina, com a finalidade de melhorar o conhecimento e a previsão desse tipo de situação. Para isso, foi feita uma climatologia sinótica das frentes frias, utilizando reanálises CFSR do NCEP e dados de precipitação do CPTEC/INPE no período 1998-2010, a partir dos quais foram separados 5% das frentes frias mais chuvosas da série. Os resultados mostram que as frentes frias que provocam chuvas mais volumosas ocorrem ao longo de todo o ano, associadas à penetração de cavados frios, intensos e pouco baroclínicos nos níveis médios e altos da atmosfera. A lenta evolução da situação meteorológica permite a intensificação de um cavado na baixa troposfera, que provoca a gradativa intensificação da instabilidade termodinâmica sobre o leste de Santa Catarina, através da advecção de calor e umidade desde a Amazônia. A frente fria que dispara a precipitação apresenta forte inclinação nos baixos níveis e lento deslocamento. Em geral, a situação meteorológica apresenta poucas variações sazonais e pode ser identificada, em média, com pelo menos 48 h de antecedência.

Development of a High-Precision Touch-Trigger Probe Using a Single Sensor

To measure various components with nano-scale precision, a new high-precision touch-trigger probe using a single low-cost sensor for a micro-coordinate measuring machine (CMM) is presented in this paper. The sensor is composed of a laser diode, a plane mirror, a focusing lens, and a quadrant photo detector (QPD). The laser beam from the laser diode with an incident angle is reflected by the plane mirror and then projected onto the quadrant photo detector (QPD) via the focusing lens. The plane mirror is adhered to the upper surface of the floating plate supported by an elastic mechanism, which can transfer the displacement of the stylus’s ball tip in 3D to the plane mirror’s vertical and tilt movement. Both motions of the plane mirror can be detected by respective QPDs. The probe mechanism was analyzed, and its structural parameters that conform to the principle of uniform sensitivity and uniform stiffness were obtained. The simulation result showed that the stiffness was equal in 3D and less than 1 mN/µm. Some experiments were performed to investigate the probe’s characteristics. It was found that the probe could detect the trigger point with uniform sensitivity, a resolution of less than 5 nm, and a repeatability of less than 4 nm. It can be used as a touch-trigger probe on a micro/nano-CMM.

Effect of the Secondary Optics and the Receiver Design on the Performance of a Triple Junction Solar Cell

In this paper, the prototype of a compact and small scale HCPV system with two-axis tracking mechanism for building integration purposes is presented and the experimental measurements are reported. The system is composed of 4 groups of optics and photovoltaic cells, each containing 8 receivers. The cells are triple junction III-V (Ga0.5In0.5P, Ga0.99In0.01As and Ge) and they have a circular shape with an active area of 4.15 mm2. The optics consists of a primary and a secondary optics: the former is a PMMA square Fresnel lens (75mm – side) with constant pitch; the latter is a refractive optics (RTP) realized with dielectric material, that i) improves the light homogeneity on the cell area, ii) reduces the negative effects of the sun-tracking misalignment and iii) increases the concentration ratio. The overall geometrical concentration ratio is 1300x. The two-axis tracking system is a tip-tilt type driven by three stepper motors, one for the tip movement and the other two for the tilt movement. The alignment with the sunrays is guaranteed by an algorithm that controls the electrical motors. The HCPV prototype was tested at the Engineering Faculty of Università Politecnica delle Marche in Ancona, Central Italy. The aim of the paper is to present the performance results, both simulated and experimental, of two different secondary optics and to assess the effect of the distance between the primary and the secondary optics on the concentration efficiency. In addition, two different solutions for the 3J cell receiver where tested, the Insulated Metal Substrate technology (IMS) and the Direct Bonded Copper (DBC). The electrical I-V curves are presented in order to assess the performance of the CPV system using the two different solutions. The experimental tests are realized under real outdoor operating conditions, therefore also the direct normal radiation (DNI) was taken into account.

Intelligent surveillance of indoor environments based on computer vision and 3D point cloud fusion

A real-time detection algorithm for intelligent surveillance is presented. The system, based on 3D change detection with respect to a complex scene model, allows intruder monitoring and detection of added and missing objects, under different illumination conditions.The proposed system has two independent stages. First, a mapping application provides an accurate 3D wide model of the scene, using a view registration approach. This registration is based on computer vision and 3D point cloud. Fusion of visual features with 3D descriptors is used in order to identify corresponding points in two consecutive views. The matching of these two views is first estimated by a pre-alignment stage, based on the tilt movement of the sensor, later they are accurately aligned by an Iterative Closest Point variant (Levenberg–Marquardt ICP), which performance has been improved by a previous filter based on geometrical assumptions.The second stage provides accurate intruder and object detection by means of a 3D change detection approach, based on Octree volumetric representation, followed by a clusters analysis. The whole scene is continuously scanned, and every captured is compared with the corresponding part of the wide model thanks to the previous analysis of the sensor movement parameters. With this purpose a tilt-axis calibration method has been developed.Tests performed show the reliable performance of the system under real conditions and the improvements provided by each stage independently. Moreover, the main goal of this application has been enhanced, for reliable intruder detection by the tilting of the sensors using its built-in motor to increase the size of the monitored area.

A new capacitive borehole tiltmeter for crustal deformation measurement and its performance analysis

Borehole inclinometers are important observation instruments used to measure ground tilt movement and monitor crustal deformation of solid tides and geological landslide disasters. They are widely used in oil exploration, mineral resource drilling, well logging, exploration and other fields. There is potential for development of rock stress strain monitoring tools. Many types of tiltmeters have been installed, such as SQ-7, FSQ, VS and JB. However, these tiltmeters are generally installed in a deep cave to avoid the interference of temperature, humidity, and human activities. With the urbanization of human society, suitable installation locations are difficult to find. To solve the problem, a two-component borehole tiltmeter, named the CBT-type tiltmeter, is proposed in this paper. It can be installed in a borehole less than 500m deep to eliminate environmental influences. The tiltmeter is composed of two sophisticated gravitational swing and two capacitive transducers. From preliminary theory and experiment analysis, its linear correlation coefficient is higher than 0.99, its co-seismic response is rapid and its noise level is up to 10−4 arc seconds in practice.

Analysis of tilt by modulated speckles generated with a double aperture pupil mask

We present a method based on modulated speckles to detect tilt movement of a diffusing surface. In our proposal a speckle image of the speckle produced by a reflective diffusing surface is formed by a lens having a double aperture. The double aperture yields to an interference process so that the resulting speckle distribution is fringe modulated. The tilting of the diffusing surface is mapped as a shifting of the speckle. Then, the double aperture pupil lens system maps the speckle shifting into a fringes shifting. We study the system performance in terms of the diffuser tilt. Experimental results that confirm our proposal are presented.

Combination of grazing incidence x-ray fluorescence with x-ray reflectivity in one table-top spectrometer for improved characterization of thin layer and implants on/in silicon wafers.

As Grazing Incidence X-ray Fluorescence (GIXRF) analysis does not provide unambiguous results for the characterization of nanometre layers as well as nanometre depth profiles of implants in silicon wafers by its own, the approach of providing additional information using the signal from X-ray Reflectivity (XRR) was tested. As GIXRF already uses an X-ray beam impinging under grazing incidence and the variation of the angle of incidence, a GIXRF spectrometer was adapted with an XRR unit to obtain data from the angle dependent fluorescence radiation as well as data from the reflected beam. A θ-2θ goniometer was simulated by combining a translation and tilt movement of a Silicon Drift detector, which allows detecting the reflected beam over 5 orders of magnitude. HfO2 layers as well as As implants in Silicon wafers in the nanometre range were characterized using this new setup. A just recently published combined evaluation approach was used for data evaluation.

SU‐E‐T‐244: Motion Control Challenges in High Dose Rate Brachytherapy

Purpose:High dose rate (HDR) brachytherapy dose distribution is highly localized and has a very sharp fall‐off. Thus the one of the most important part of the treatment is the localization and immobilization of the applicator from the implantation to the setup verification to the treatment delivery. The smallest motions of the patient can induce a small rotation, tilt, or translational movement of the applicator that can convert into miss of a significant part of the tumor or to over irradiating a nearby critical organ. The purpose of this study is to revise most of the HDR types of treatments with their applicators and their localization challenges. Since every millimeter of misplacement counts the study will look into the necessity of increasing the immobilization for several types of applicators.Methods:The study took over 136 plans generated by the treatment planning system (TPS) looking into the applicator placement in regard to the organs at risk (OR) and simulated the three possible displacements at the hottest dose point on the critical organ for several accessories to evaluate the variation of the delivered dose at the point due to the displacement.Results:Many of the present immobilization devices produced for external radiotherapy can be used to improve the localization of HDR applicators during transportation of the patient and during treatment.Conclusion:This study data indicates that an improvement of the immobilization devices for HDR is absolutely necessary. Better applicator fixation devices are required too. Developing new immobilization devices for all the applicators is recommended.

Movements of the horse’s mouth in relation to horse–rider kinematic variables

The aim of this study was to investigate the behavioural response of horses to rein contact and the movement of the riders’ hands through analysis of data from horses ridden at two different head and neck positions. It was hypothesised that the riders’ hand movements and rein tension would generate behavioural responses from horses and that these responses would be more marked when horses were ridden ‘on the bit’ than when unrestrained. Data were collected from seven dressage horse/rider combinations at sitting trot on a high speed treadmill. Kinematics were recorded using a 12-camera, infrared-based opto-electronic system. Three horses wore a rein tension meter. Behavioural registrations were made from video. Behavioural responses included lip movement, mouth movement, open mouth, change in ear position, head tilt and tail movement. Mouth movements were associated with the suspension phase of the trot. Head and neck position was non-significant in the final models, while rein tension and the distance between the rider’s hand and the horse’s mouth were related to mouth movements. Interactions between horses and riders are complex and highly variable.

Attitude Angle Measurement Method Based on the Three-Dimensional Accelerometer

On the basis of a study of measuring inclination angle with a two-dimensional accelerometer, a principle method using a three-dimensional accelerometer to measure attitude angle is analysed on the condition of micro-rotating. The method can reduce random systematic errors caused by uniaxial or biaxial output of the two-dimensional accelerometer. It can simultaneously measure both inclination angle and roll angle. So hardware selection, hardware circuit design and experiments are done: simulate the roll and tilt movement of the special objects and compare the solver results with the actual results. The principle method achieves preferable results, and provides a theoretical support for attitude determination of a particular industry as well.

The Clarification of the Strategy during Sit-to-Stand Motion from the Standpoint of Mechanical Energy Transfer

[Purpose] This study aimed to clarify the motion strategy used by young healthy adults during sit-tostand motion (STS) and to investigate the relationship between forward tilt movement by the trunk and shanks, which is considered to contribute to the forward shift of COG, and the load on the lower extremity joints accept, from the standpoint of mechanical energy flow. [Subjects] The subjects were 10 young healthy males without disease and/or present history of illnesses that would affect STS. [Methods] Three kinds of task conditions were adopted: normal STS (condition N), STS with the trunk tilted as forward as possible (condition TM), and STS with the trunk as vertical as possible (condition TV). The kinematic data during STS were collected using a three-dimensional motion analysis system, and the kinetic data were collected by force plates. [Results] The average negative power in the proximal portions of the shank under condition TV was significantly higher than that under conditions N and TM. [Conclusion] Shank forward tilt appears to be primarily a reactive movement facilitating knee extension rather than contributing to moving COG forward. Thus, less trunk forward tilt movement results in the requirement of higher ability of shank forward tilt movement.

A New Surgical Instrument and Technique Designed To Achieve More Accurate Component Placement in Total Hip Replacement

Most US surgeons perform THR surgery with their patients in a lateral decubitus position and rely on maintaining that precise position when implanting the final components. Most surgeons have not had a reliable way to visualize changes in pelvic positioning or an accurate way to restore patient positioning. The purpose of this study is to describe a simple technique using a new device that allows for more accurate assessment of the degree of pelvic tilt and a method to correct for, and potentially improve, the accuracy when using a traditional cup alignment guide. The pelvic alignment level is a sterile, single-use surgical instrument designed to address: pelvic tilt movement to improve accuracy of leg length and femoral offset, intraoperative pelvic rotation in the transverse place to optimize acetabular implant placement, and achieve desired cup inclination and anteversion to help reduce the chance for postoperative dislocation.

Spectral phase, amplitude, and spatial modulation from ultraviolet to infrared with a reflective MEMS pulse shaper

We describe the performance of a reflective pulse-shaper based on a Micro-ElectroMechanical System (MEMS) linear mirror array. It represents a substantial upgrade of a preceding release [Opt. Lett. 35, 3102 (2010)] as it allows simultaneous piston and tilt mirror motion, allowing both phase- and binary amplitude-shaping with no wavelength restriction. Moreover, we show how the combination of in-axis and tilt movement can be used for active correction of spatial chirp.

1P1-A26 動揺病の数理モデルを用いた自動車乗員の頭部運動の解析

Driver receives the acceleration and the rotational stimulations when negotiating with a curve. In such a situation, the driver controls his/her posture such as the head and the body appropriately. Beside, it is pointed out that the head movement of the passenger is opposite to the driver. Moreover, by the fact that the driver does not get carsickness comparing with the passenger, it is suggested that the driver's head movement may be related to the decrease of carsickness and improvement of the ride comfort. Therefore, we build the mathematical model of the motion sickness and investigated the relation between the head movement and the motion sickness incidence. In addition, we simulate motion sickness incidence using driver's head movements measured in the experiments with a real car. From the result, it is shown that the head tilt movement of the driver's head movement has an effect to decrease the motion sickness.

Modeling and design of a novel precision tilt positioning mechanism for inter-satelliteoptical communication

The compact precise tilt positioning mechanism (PTPM) determines the performance ofinter-satellite optical communication systems. This paper presents a novel structural designof a PTPM in which the tilt movement is implemented by the elastic deformation of aflexure ring. The flexure ring promises zero friction and zero clearance. The stiffness modelof the flexible ring was built based on an analysis of the structural mechanics. Then adynamic model is presented based on the Lagrange equation. A modal analysis and anexperimental investigation were performed. The error between the three methods is lessthan 10%.

倒立振り子モデルを利用した身体前後傾斜運動時の立位安定性の定量評価に関する検討(機械力学,計測,自動制御)

倒立振り子モデルを利用した身体前後傾斜運動時の立位安定性の定量評価に関する検討(機械力学,計測,自動制御)

A visual sign of lateral acceleration for steering assistance

This work examines whether it is possible to compensate for the loss of vestibular information that is usually felt by drivers of modern cars when negotiating bends and which is associated with the load transfer of the car. Indeed, the absence of this information causes drivers to underestimate their speed and consequently increases the risk of road departure. This study tries to visually compensate for this loss of vestibular information through a tilt movement of the frame of reference of the driver. This tilt is the same as that perceived in a bend because of the load transfer of the car. The results indicate that most participants are influenced by this visual information and modify their speed accordingly whilst taking a bend. Nevertheless, only those participants uninformed about the presence of this assistance did slow down, whereas informed participants accelerated. This effect has been interpreted as a consequence of the level of processing implicated in the steering task (implicit versus explicit processing).

Costa Recta beach, Deception Island, West Antarctica: a retreated scarp of a submarine fault?

Deception Island (South Shetlands, Antarctica) is one of the most active volcanoes in Antarctica, having erupted recently in 1967, 1969 and 1970, damaging scientific stations on the island. It is also seismically very active. The island has attracted the attention of many researchers as it constitutes an undisturbed natural laboratory to study seismo-volcanic events and how they affect landscape modelling and evolution. One of the most remarkable geological and geomorphological features on Deception Island is the linearity of its easternmost coastal landform, the origin of which remains unknown. Some answers, based on presence of strike-slip fault or on the ice cap and beach geomorphological dynamics, have been reported in the literature. Our new work provides several indications of the existence of a dip-slip submarine fault, parallel to the coast (NNW–SSE), which suggests a tectonic origin for this morphological feature. Uplifted marine terraces, incision of a fluvial network over the ice cap, normal faulting parallel to the coast in the north and south rock heads bounding the beach and sharp shelf-break with rather constant slope, constitute some of this evidence. Terrace uplift and fluvial channel incision decreasing southward from Macaroni Point, indicates possible tilt movement across this inferred fault plane.