A psychophysical and questionnaire investigation on the spatial disorientation triggered by cockpit layout and design

This study assessed Taiwanese air force combat jet pilots' ability to cope with spatial disorientation (SD) triggered by cockpit layout and design. The measurement items of psychophysical questionnaire were ranked by 325 air force combat jet pilots. This study prioritized the causes of SD perceived by combat jet pilots resulted from the unfamiliarity with instruments on aircraft undergoing flight training, the aircraft's cockpit canopy and the layout of instruments in the cockpit. A significant difference was found between with-SD experience and without-SD experience subjects' responses from adapting to the size of instruments in the cockpit, and from the helmet-mounted display (HMD). Considerable association was discernible between the position of instruments in the cockpit and combat jet models accrued; as well as between the helmet-mounted display (HMD) and combat jet models accrued. The study identify main cockpit layout and design causing SD of Taiwanese pilots based on combat jet models to eliminate the risk of SD, intensify SD training on preventing SD and provide pilots with skills to anticipate and assess the risk of SD during mission planning, and provide references to the military for future procurement of new aircraft models.Relevance to industryThese results provide important information to the defense manufacturers for designing the cockpit layout of combat jets to prevent SD of specific pilots. Finally, the results show the contribution of ergonomics to support military operational commanders in the design of training and prevention of SD.     

Dynamics and control of a spatial disorientation trainer

Modern combat aircraft can fly at unusual orientations. The spatial disorientation trainer (SDT) examines a pilot's ability to recognise these orientations, to adapt to unusual positions and to persuade the pilot to believe in the aircraft instruments for orientation and not in his own senses. The SDT is designed as a four-degree-of-freedom (4DoF) manipulator with rotational axes. Through rotations about these axes, different orientations can be achieved; different acceleration forces acting on the pilot can also be simulated. In this paper, a control algorithm of an SDT that improves the quality and safety of the SDT motion while improving position accuracy and reducing servo errors is proposed. This control algorithm uses approximate inverse dynamics based on the recursive Newton–Euler algorithm, which accounts for the motors present in the system; it calculates motor torques, as well as the forces and moments acting on the SDT links based on the achievable velocities and accelerations of the robot links. This algorithm enables accurate dimensioning of the axes bearings and links as well. The maximum possible accelerations of the SDT links are calculated in each interpolation period based on the total moments of inertia for the axes of rotation of these links, mutual influences of the link accelerations on each other, and motor capabilities. The forces, moments and torques that act on the SDT links obtained with the suggested algorithm have lower magnitude and smoother profile. In this study, the forces and angular velocities that act on the simulator pilot in the SDT are calculated along with the roll and pitch angles of the gondola for these forces.     

The instrument explosion--a study of aircraft cockpit instruments

Aircraft cockpit instruments have been increasing in number since the Wright Brothers made their first powered flight. As aeroplane development progresses, new systems are continually being added to improve performance or capability and cockpits have now reached the stage where there is often little space left in which to install the monitoring instruments for these additional systems. Fortunately, the advent of electronic cockpit displays offers a solution to this problem. One electronic display can be used to present the information previously requiring several conventional electro-mechanical instruments, with a consequent saving in cockpit panel space. However, cockpit displays must be matched to the pilot's information requirements and processing abilities. If this is not done the advantages of electronic displays will not be realised and the pilot will be in an even worse position than he was before.     

Collision-avoidance for redundant robots through control of the self-motion of the manipulator

A new method to on-line collision-avoidance of the links of redundant robots with obstacles is presented. The method allows the use of redundant degrees of freedom such that a manipulator can avoid obstacles while tracking the desired end-effector trajectory. It is supposed that the obstacles in the workspace of the manipulator are presented by convex polygons. The recognition of collisions of the links of the manipulator with obstacles results on-line through a nonsensory method. For every link of the redundant manipulator and every obstacle a boundary ellipse is defined in workspace such that there is no collision if the robot joints are outside these ellipses. In case a collision is imminent, the collision-avoidance algorithm compute the self-motion movements necessary to avoid the collision. The method is based on coordinate transformation and inverse kinematics and leads to the favorable use of the abilities of redundant robots to avoid the collisions with obstacles while tracking the end-effector trajectory. This method has the advantage that the configuration of the manipulator after collision-avoidance can be influenced by further requirements such as avoidance of singularities, joint limits, etc. The effectiveness of the proposed method is discussed by theoretical considerations and illustrated by simulation of the motion of three-and four-link planar manipulators between obstacles.     

A wireless embedded tongue tactile biofeedback system for balance control

We describe the architecture of an original biofeedback system for balance improvement for fall prevention and present results of a feasibility study. The underlying principle of this biofeedback consists of providing supplementary information related to foot sole pressure distribution through a wireless embedded tongue-placed tactile output device.Twelve young healthy adults voluntarily participated in this experiment. They were asked to stand as immobile as possible with their eyes closed in two conditions of no-biofeedback and biofeedback. Centre of foot pressure (CoP) displacements were recorded using a force platform. Results showed reduced CoP displacements in the biofeedback relative to the no-biofeedback condition.On the whole, the present findings evidence the effectiveness of this system in improving postural control on young healthy adults. Further investigations are needed to strengthen the potential clinical value of this device.     

Singularity-consistent path planning and motion control through instantaneous self-motion singularities of parallel-link manipulators

The newly proposed singularity-consistent path tracking approach is applied to nonredundant parallel-link manipulators. We analyze the singularities of such manipulators under the assumption that the output-link moves on a pre-defined and parameterized path. Special attention is paid to the so-called instantaneous self-motion type singularity. We propose a velocity-command generator type closed-loop controller that guarantees asymptotic stability when tracking paths through such singularities. As a comprehensive analytical example we use a planar five bar mechanism. Results from computer simulations with the five bar mechanism and the HEXA parallel robot are also presented. © 1997 John Wiley & Sons, Inc.     

基于多最小支持度的空间关联规则发现

空间关联规则挖掘可应用于发现空间数据库中大量空间谓词与非空间谓词之间的特定空间关系。论文针对区县道路交通数据提出了一种基于多最小支持度的空间关联规则挖掘算法,并给出了在GIS中进行空间关联规则挖掘的一般方法和流程。该挖掘算法可以从城市道路地理信息数据库中发现用户感兴趣的空间关联规则,经实际应用于城市道路规划管理系统,证明该算法是有效、可行的。     

基于以太网的智能过程控制仪表的设计

介绍了以Rabbit2000型微处理器为核心的嵌入式模块RCM2200,并以RCM2200为核心设计出新型智能过程控制仪表。该仪表除了具有数据采集、分析、显示、存储等功能外,还带有10M的以太网端口。Ethernet+TCP/IP的应用可以使仪表很方便地连接到Internet上,完成仪表的信息交换和远程监控的功能。     

空间分形Julia集的辨识控制

由于空间分形Julia集合的参数辨识问题在典型的Langevin问题中尚未解决,本文提出一种新的方法设计了普遍适用的自适应同步控制器和参数自适应律的解析表达式,解决了在驱动系统参数未知的情况下无法实现同步控制的问题,并且在实现渐近同步的过程中能够辨识出驱动系统的未知参数,通过仿真示例验证了该方法有效.另外,该方法也适用于最基本的Julia集.     

On the influence of morphology of tactile sensors for behavior and control

Many different animal species rely on whiskers for a variety of tasks. Among the most basic are obstacle avoidance and wall-following. We show that fast and reliable evaluation of distances can be greatly improved by an appropriate sensory morphology that matches the physical space of the agent. To investigate morphologies and material properties of whiskers, we conduct experiments both on a real robot and in simulation using artificial evolution. We find that the morphology that is most successful at following a wall strongly resembles the morphologies of natural whiskers. This can be better understood by considering the relation of the agent body to its tactile sensing range, as well as the challenges of various tasks faced by agents endowed with different sensory modalities.     

风机盘管空调器的模糊变频控制

一种利用单片机实现的风机盘管空调器模糊变频控制器的硬件和软件设计。该控制器集模糊逻辑控制和数字式正弦波脉宽调制变频控制于一体,可自动调节风机转速和供冷（热）水量。     

甲基紫试验仪控温系统

介绍了甲基紫试验仪温度控制系统的组成,设计方法。对仪器进行了温度控制实验,温度控制系统在120℃和134.5℃实验中,在50min时达到稳定,误差在±0.1℃以下,满足预定要求;结果表明,控温系统性能可靠。     

The design and control of a robot finger for tactile sensing

This article describes the design and control of a lightweight robot finger intended for tactile sensing research. The finger is a three-link planar chain with the joints actuated through cables by two motors. Kinematic coupling of the three joints provides two degrees of freedom for finger tip manipulation, and a curling action of the finger for enclosing an object. Hall effect sensors in each joint provide position feedback, and strain gage sensors on each cable provide tension information. To minimize weight and power consumption, a high speed low torque motor together with a 172:1 speed reducer is used as the actuator. A force control loop around the motor speed reducer system reduces the effect of the friction inherent in the speed reducer. Flat mounting plates are provided on each link for special purpose grasping surfaces and sensors.     

A comparative study of active and passive displays for aircraft cockpit use

An experimental study is reported of a comparison of an active and a passive display viewed by a subject previously adapted to a bright field of view. Results showed that both displays were legible in high direct illumination, but that the legibility of the passive display became poor when illuminated at only moderate levels. Degrading the display enhanced this effect. A study of the errors made on reading the alphanumeric characters is also reported. Results do not agree well with previous experiments using the same fount and it is suggested that it may be more difficult to generalize from such tests than generally believed.     

A novel model for assessing sliding mechanics and tactile sensation of human-like fingertips during slip action

This paper presents a model for displaying friction and localized stick/slip of sliding inhomogeneous human-like fingertips, to understand how slippage occurs and its role in assessing tactile sensing mechanics. In the absence of friction, the fingertip slides, as on an ice surface, in the virtual world of haptic interfaces. Slippage of fingertip at very low velocity can reflect micro stick/slip on a contact area, which is challenging to represent in any friction model. To overcome these drawbacks, we propose that a Beam Bundle Model (BBM) can be used to model a human fingertip during pushing and sliding actions, especially during stick-to-slip transition. To construct its three-dimensional, non-homogeneous structure, we obtained a sequential series of magnetic resonance images, showing consecutive cross-sectional layers of a fingertip with distribution of skin, tissue, bone, and nail. Simulation results showed that this model could generate not only normal force distribution caused by pushing, but also response of friction during stick-to-slip transition. Secondly, and more interestingly, the model dynamically produced localized displacement phenomena on the contact area during stick-to-slip phase, indicating how slippage enlarges the contact area prior to total slippage of the fingertip. These findings may better assess the sliding processes of human fingertips, and how and when slippage occurs on the contact surface. This model may be a useful platform for studying tactile perception of fingertips.     

Neural network modeling supports a theory on the hierarchical control of prehension

A theory on the hierarchical organization of the control of human prehension (grasping and manipulation of a hand-held object) was tested by comparing the performances of neural networks of different designs. The inputs into the networks were external torque, handle width, and thumb location, and the outputs were the individual digit forces. The networks differed only in their architecture: N1 was a classical three-layer network; N2 was a hierarchical two-tier network with single projections, in which the outputs of the first tier were used as inputs for the second tier, that yielded the individual digit forces; and N3 was a hierarchical two-tier network with dual projections, where the inputs to the second tier were the outputs of the first tier—as in N2—plus the inputs into the first tier (external torque, handle width, and thumb location). Each tier of N2 and N3 consisted of one three-layer network. The N3 network showed the best performance, supporting the idea that the control of prehension is hierarchically organized.     

仪表指针压制嵌入式控制软件设计

汽车电子配件的生产制造逐渐由自动化步入智能化,汽车仪表指针的智能压制也成了众多汽车生产企业研究的对象。介绍了基于S3C6410的Windows CE平台的汽车仪表指针压制系统的整机工作流程、硬件结构原理、人机界面和SQLite数据库的设计开发过程。进行了整机测试,试验结果表明,本压制系统与老式压制机相比,具有良好的人机界面,操作灵活方便,且有较高的精确度和效率,完全能满足汽车配件厂的生产要求。     

A medium access control protocol that supports a seamless handover in wireless sensor networks

This paper introduces a mobility-aware medium access control protocol for multi-hop wireless sensor networks (MA-MAC). The protocol evaluates the RSSI values of acknowledgement packets and determines whether a gradual deterioration in the RSSI values eventually leads to a disconnection. If it does, it initiates a handover by switching transmission from a unicast to a broadcast mode and by embedding neighbour discovery requests in the broadcast data packets. While the mobile node continues transmitting data packets via the existing link, the neighbour discovery requests enable it to discover new nodes that can serve as intermediate nodes. Once an intermediate node is found, the mobile node establishes a link with it and switches transmission back to unicast. Conceptually, MA-MAC's handover feature can be implemented by extending any of the existing transmitter initiated, energy-efficient protocols such as XMAC or BMAC. Our present implementation is based on the XMAC protocol. The paper reports how the protocol performs as the speed of mobility, handover threshold, and sending interval vary.     

A spatial variant approach for vergence control in complex scenes

The flexibility in primate vision that utilizes active binocular vision is unparalleled even with modern fixed-stereo-based vision systems. However to follow the path of active binocular vision, the difficulty of attaining fixative capabilities is of primary concern. This paper presents a binocular vergence model that utilizes the retino-cortical log polar mapping in the primate vision system. Individual images of the binocular pair were converted to multi-resolution pyramids bearing a coarse-to-fine architecture (low resolution to high resolution) and disparity estimation on these pyramidal resolutions was performed using normalized cross correlation on the log polar images. The model was deployed on an actual binocular vergence system with independent pan-tilt controls for each camera and the system was able to robustly verge on objects even in cluttered environment with real time performance. This paper even presents the experimental results of the system functioning in unbalanced contrast exposures between the two cameras. The results proved favorable for real world robotic vision applications where noise is prevalent. The proposed vergence control model was also compared with a standard window based Cartesian stereo matching method and showed superior performance.     

A formal model for access control with supporting spatial context

There is an emerging recognition of the importance of utilizing contextual informa tion in authorization decisions. Controlling access to resources in the field of wireless and mobile networking require the definition of a formal model for access control with supporting spatial context. However, traditional RBAC model does not specify these spatial requirements. In this paper, we extend the existing RBAC model and propose the SC-RBAC model that utilizes spatial and location-based information in security policy definitions. The concept of spatial role is presented, and the role is assigned a logical location domain to specify the spatial boundary. Roles are activated based on the current physical position of the user which obtained from a specific mobile terminal. We then extend SC-RBAC to deal with hierarchies, modeling permission, user and activation inheritance, and prove that the hierarchical spatial roles are capable of constructing a lattice which is a means for articulate multi-level security policy and more suitable to control the information flow security for safety-critical location-aware information systems. Next, constrained SC-RBAC allows express various spatial separations of duty constraints, location-based cardinality and temporal constraints for specify fine-grained spatial semantics that are typical in location-aware systems. Finally, we introduce 9 invariants for the constrained SC-RBAC and its basic security theorem is proven. The constrained SC-RBAC provides the foundation for applications in need of the constrained spatial context aware access control.