Training in a Continuous Ball Throwing and Catching Task

Abstract

A continuous ball throwing and catching task in which the ball remained captive on the end of a chain was given to 84 male students between the ages of 18 and 38 years. Initial and final test trials were carried out without restriction on viewing the ball throughout its trajectory, whereas the interspersed training trials (except for a control group) wero carried out under restricted (spatial) viewing conditions. Results supported the contention that it is not necessary to ‘ keep one's eye on the ball’ in order to obtain performance seores as good as those obtained when the opportunity to watch the ball all the time is available. Suggestions are made with regard to ‘ guidance ’ as a training device.     

Effects of redundancy in the comparison of speech and pictorial displays in the cockpit environment

Synthesised speech and pictorial displays were compared in a spatially compatible simulated cockpit environment. Messages of high or low levels of redundancy were presented to subjects in both modality conditions. Subjects responded to warnings presented in a warning-only condition and in a dual-task condition, in which a simulated flight task was performed with visual and manual input/output modalities. Because the amount of information presented in most real-world applications and experimental paradigms is quantifiably large with respect to present guidelines for the use of synthesised speech warnings, the low-redundancy condition was hypothesised to allow for better performance. Results showed that subjects respond quicker to messages of low redundancy in both modalities. It is suggested that speech messages with low-redundancy levels were effective in minimising message length and ensuring that messages did not overload the short-term memory required to process and maintain speech in memory. Manipulation of phrase structure was used to optimise message redundancy and enhance the conceptual compatibility of the message without increasing message length or imposing a perceptual cost or memory overload. The results also suggest that system response times were quicker when synthesised speech warnings were used. This result is consistent with predictions from multiple resource theory which states that the resources required for the perception of verbal warnings are different from those for the flight task. It is also suggested that the perception of a pictorial display requires the same resources used for the perception of the primary flight task. An alternative explanation is that pictorial displays impose a visual scanning cost which is responsible for decreased performance. Based on the findings reported here, it is suggested that speech displays be incorporated in a spatially compatible cockpit environment because they allow equal or better performance when compared with pictorial displays. More importantly, the amount of time that the operator must direct his vision away from information vital to the flight task is decreased.     

Peripheral arterial tone as an on-line measure of load in a simulated flight task

Variations in continuous and discrete flight demands were investigated in a simulated flight mission measuring peripheral arterial tone (PAT) from the tip of the finger. A total of 12 participants performed a computer-simulated agricultural flight task. They were required to fly over a specific lane of a simulated corn field (continuous task) and change lanes in response to flags, which appeared at varying intervals (discrete task). The difficulty of the flight task was manipulated by varying the airplane control (single- vs. dual-axis control), while the difficulty of the discrete task was manipulated by varying the amount of lateral change signalled by the flag. PAT amplitude was lower in the difficult level of the continuous task and was further attenuated following the appearance of the flag only when a change in the flight position was required. These results suggest the potential utility of PAT as an on-line measure of the joint continuous and discrete demands of a flight mission.     

Peripheral arterial tone as an on-line measure of load in a simulated flight task

Variations in continuous and discrete flight demands were investigated in a simulated flight mission measuring peripheral arterial tone (PAT) from the tip of the finger. A total of 12 participants performed a computer-simulated agricultural flight task. They were required to fly over a specific lane of a simulated corn field (continuous task) and change lanes in response to flags, which appeared at varying intervals (discrete task). The difficulty of the flight task was manipulated by varying the airplane control (single- vs. dual-axis control), while the difficulty of the discrete task was manipulated by varying the amount of lateral change signalled by the flag. PAT amplitude was lower in the difficult level of the continuous task and was further attenuated following the appearance of the flag only when a change in the flight position was required. These results suggest the potential utility of PAT as an on-line measure of the joint continuous and discrete demands of a flight mission.     

无人直升机实时机载和地面站软件架构设计

研究了无人直升机飞行控制系统实时软件系统设计架构,针对机载嵌入式飞控计算机系统和地面站计算机系统,提出了基于VxWorks实时操作系统的多线程任务机载软件设计方案和基于WindowsXP操作系统的地面站软件设计方案,有助于加快完成无人直升机飞行控制系统的设计和验证。机载系统软件设计为数据采集和测量、伺服舵机驱动、飞行控制与发动机控制实现、通信和数据请求存储等功能。地面站系统软件设计为与机载系统的数据通信、终端用户操控,以及实时飞行状态监视等功能。利用组件对象模型设计技术实现了系统软件设计的模块化、软件结构分层组件化,方便了软件系统的集成与扩展。采用多任务线程机制,有效地满足了飞行控制系统实时性要求。利用实时操作系统的定时器任务机制,确保飞行模式的任务管理和调度。依据所提出的软件设计架构完成了实时机载软件和地面站软件组件模块的设计与开发,而且软件集成快捷方便。研究成果已成功应用于某型无人直升机飞行控制系统。     

飞行控制软件周期任务的定时周期设计

飞行控制系统是典型的硬实时系统,任务周期设计是飞行控制系统设计的基础。为了保证飞行控制软件满足实时性和功能性要求,在系统设计初期进行的任务周期设计首先需要根据任务功能、时限要求和设计指标的不同,区分每个任务周期设计的侧重点并进行分类;结合飞行控制软件中周期任务的特点,确定飞行控制软件中任务周期设计的所有时间约束;根据任务的所有的时间约束条件进行任务周期的设计。这种设计思路及方法已经在具体案例的设计中使用,其对于飞行控制软件的设计具有很好的参考意义。     

机组告警信息地面实时监控系统设计

机组告警信息对于保障民机飞行安全有着至关重要的作用,为了保障民机试飞地面安全实时监控任务,需要开发一套系统能够在试飞过程中精确地给出机组告警信息.机组告警信息内容来源于机上多个子系统,重点研究了如何从遥测接收的PCM流中精确解析出告警信息以及地面实时系统各个模块间的通信及功能设计.采用了典型的C/S (Client/Server)结构来搭建系统,通过对告警信息进行分类判决和设计虚警抑制机制实现了机组告警信息的正确解析.经多个飞行起落验证,该系统运行稳健,告警信息与机上显示内容相符,可满足地面指挥和试飞工程师的监控需求.该系统为民机试飞任务的顺利进行提供了保障,值得后续民机型号借鉴.     

基于云计算的航空飞行试验数据中心任务调度优化架构设计

为解决航空飞行试验数据中心任务调度行为明显滞后的问题,实现对航空飞行试验数据的实时调度,设计基于云计算的航空飞行试验数据中心任务调度优化架构。设置WiRo中心网络,联合试验数据预测器与飞行任务分配器,完善中心任务调度优化架构体系的基础应用结构设计。根据PSO优化度量值的取值范围,求解惯性权重指标与粒子编码条件,并按照云计算法则,推导函数表达式条件,实现基于云计算的航空飞行试验数据调度模型的构建。在动态数据权限的约束下,计算中心调度任务的资源占用率与长尾延迟参数,实现对任务调度架构的优化配置,联合WiRo中心网络及EMU调度结构,完成基于云计算的航空飞行试验数据中心任务调度优化架构的设计。实验结果表明,云计算技术作用下,单位时间内的数据吞吐量达到了9.85B/s,由数据吞吐量有限造成的中心任务调度行为滞后的问题得到较好解决,符合实时调度航空飞行试验数据的实际应用需求。     

Static and dynamic postural loadings during computer work in females: Sitting on an office chair versus sitting on an exercise ball

Seated computer work results in prolonged static loading, which has been associated with the development of musculoskeletal disorders. A popular alternative to sitting on an office chair while performing computer work is to sit on an exercise ball. Sitting on an exercise ball might affect static and dynamic aspects of working posture. We monitored posture, muscle activation and spinal shrinkage in 10 females performing a 1-h typing task, while sitting on an office chair with armrests and while sitting on an exercise ball. Sitting on an exercise ball resulted in 33% more trunk motion and in 66% more variation in lumbar EMG. Both of these findings can be considered to be an advantage for the exercise ball. However, the fifth percentile and average lumbar EMG were also higher when sitting on an exercise ball, with 38% and 78%, respectively. In addition, more spinal shrinkage occurred when sitting on an exercise ball than when sitting on an office chair. Arm flexion was reduced, but trapezius activation was unaffected when sitting on an exercise ball. It is concluded that the advantages with respect to physical loading of sitting on an exercise ball may not outweigh the disadvantages.     

Helicopter pilots’ views of air traffic controller responsibilities: a mismatch

Abstract

Controllers and pilots must work together to ensure safe and efficient helicopter flight within the London control zone. Subjective ratings of pilot perception of controller responsibility for five key flight tasks were obtained from thirty helicopter pilots. Three types of airspace were investigated. Results indicate that there is variation in pilot understanding of controller responsibility compared to the formal regulations that define controller responsibility. Significant differences in the perception of controller responsibility were found for the task of aircraft separation in class D airspace and along helicopter routes. Analysis of the patterns of response suggests that task type rather than the airspace type may be the key factor. Results are framed using the concept of a shared mental model. This research demonstrates that pilots flying in complex London airspace have an expectation of controller responsibility for certain flight tasks, in certain airspace types that is not supported by aviation regulation.

Practitioner Summary: The responsibility for tasks during flight varies according to the flight rules used and airspace type. Helicopter pilots may attribute responsibility to controllers for tasks when controllers have no responsibility as defined by regulation. This variation between pilot perceptions of controller responsibility could affect safety within the London control zone.     

Visuo-motor learning for face-to-face pass between heterogeneous humanoids

Humanoid behavior generation is one of the most formidable issues due to its complicated structure with many degrees of freedom. This paper proposes a controller for a humanoid to cope with this issue. A given task is decomposed into a sequence of modules first, each of which consists of a set of module primitives that have control parameters to realize the appropriate primitive motions. Then, these parameters are learned by sensorimotor maps between visual information (flow) and motor commands. The controller accomplishes a given task by selecting a module, a module primitive in the selected module, and its appropriate control parameters learned in advance. A face-to-face ball pass in a RoboCup context is chosen as an example task. (To the best of our knowledge, this is the first trial.) The corresponding modules are approaching a ball, kicking a ball to the opponent, and trapping a ball coming to the player. In order to show the validity, the method is applied to two different humanoids, independently, and they succeed in realizing the face-to-face pass for more than three rounds.     

Factors affecting task management in aviation

OBJECTIVE: We investigated the influence of ongoing task display "compellingness" on attention allocation patterns and assessed its interaction with interrupting task salience and importance. BACKGROUND: There are some concerns that the compellingness of flight deck tunnel displays renders the task they support more resistant to interruptions, thus preventing the pilot from noticing cues signaling the need to divert attention to other tasks. METHODS: Forty pilots flew three curved approaches in a high-fidelity simulation using a synthetic vision system (SVS) display. In addition to the primary task of flying, during the last approach they were required to select the approach path on the basis of environmental information concerning weather. The display layout supporting the primary flight task (tunnel vs. baseline display), the nature of the cue signaling the need to divert attention to the path selection task (visual vs. auditory-visual cue), and the cost of not performing the secondary task were manipulated to investigate their influence on task prioritization. RESULTS: The modality and priority of the cue affected the frequency of the switch to the secondary task. Furthermore, pilots flying with a tunnel display were more likely to detect the change in the weather and were easily interrupted by the secondary task when priority was high. CONCLUSION: Our results suggest that some of the concerns regarding the negative consequences of the compelling nature of the tunnel display may not be as pronounced as thought. APPLICATIONS: This study highlights the utility of the tunnel display in improving flight safety.     

The Sternberg memory search task as an index of pilot workload

Abstract

The rationale for the use of the Sternberg memory search task as a diagnostic measure of pilot workload is described, and seven investigations that have employed this task in flight simulators or aircraft environments are summarized. The details of two further flight simulator experiments in which workload is measured by an auditory Sternberg task are reported. These results indicate the diagnostic value of the task in discriminating between the perceptual/central processing and response demands of a holding pattern and an approach pattern, respectively. Perceptual and response load were greater in an approach phase, relative to a holding phase. Neither phase imposed a substantial central processing load. Based upon the findings of the studies described, the paper concludes with a set of recommendations for employing the Sternberg task in aviation environments. These recommendations emphasize the importance of information display and response procedures, the choice of particular memory sets, the presentation of data, and the need to avoid extremely difficult flight tasks.     

A Learning Approach to Robotic Table Tennis

We propose a method of controlling a table tennis robot so as to return the incoming ball to a desired point on the table with specified flight duration. The proposed method consists of the following three input–output maps implemented by means of locally weighted regression: 1) a map for predicting the impact time of the ball hit by the paddle and the ball position and velocity at that moment according to input vectors describing the state of the incoming ball; 2) a map representing a change in ball velocities before and after impact; and 3) a map giving the relation between the ball velocity just after impact and the landing point and time of the returned ball. We also propose a feed-forward control scheme based on iterative learning control to accurately achieve the stroke movement of the paddle as determined by using these maps. Experimental results including rallies with a human opponent are also reported to demonstrate the effectiveness of our approach.     

A preliminary study on learning effect in a contact positioning task in a virtual environment

How the human central nervous system adjusts sensorimotor coordination to haptic stimuli is a major topic in several fields including robotics. There are studies focusing on contact positioning tasks such as catching a ball or a volley in tennis, where position control of a human hand is required only at the moment of contact for successful completion of the tasks. A previous study dealt with a task of catching a ball in a virtual environment, and reported an interesting observation of the learning process in the relationship between operational performance and energy consumption of an operator; however, the operational condition given to the operators in the previous study seemed to be relatively simple. The interest in this paper is similar to that of the previous study; however, this paper considers application of a slightly more complex operational condition to a task of catching a ball. For corresponding to increase of difficulty in operation in the task, two movements of a paddle for catching a ball are given to operators, and difference between the movements is observed. Although the final goal of the study in this paper is similar to that in the previous study, this paper considers how learning effect can be observed in operational performance by comparing the performance of novice operators with that of experienced operators. The comparison shows differences in the performances between the operators from three analytic aspects. This paper also considers how many operations are required for novice operators to exhibit the learning effect in operational performance.     

On the flight of a golf ball in the vertical plane

The equations of motion for a ball moving in a vertical plane are used to calculate flight paths for a typical golf ball subjected to a variety of launch conditions, spin rates, atmospheric parameters, and wind fields. Time histories of the ball's velocity, flight-path angle, height, range, and spin rate between tee and first impact illustrate that lift induced by the ball's spin has a significant effect on driving range, actually causing the flight-path angle to increase during the first few seconds of flight. While light winds have the expected effects, heavy tailwind is shown to spoil the carry of the ball. Linearized sensitivity analysis indicates that wind uncertainty is an important contributor to impact range and time uncertainty. Editor: H. Flashner     

Transfer and motor skill learning in association football

Transfer of learning involves the influence of previous experiences on the performance or learning of new skills. It is defined as a gain (or loss) in the capability for performance on one task as a result of practice on another. The aim of the study was to examine the degree of transfer between various association football skills. Twenty intermediate male players participated in the study. During pre- and post-training tests, participants juggled a football as many times as possible within 30 s using feet or knees. Further tests required participants to control an approaching football inside a restricted area using the preferred and non-preferred kicking leg. Following performance on the pretest, two matched skill groups were obtained. One group participated in a 4-week training period in which feet-only ball juggling was practised for 10 min daily, while the remaining group acted as a control. Trained participants exhibited superior post-test performance on knee juggling and ball control with preferred and non-preferred leg tasks relative to the control group (p < 0.05). Findings indicate positive transfer of learning from juggling practice with the feet to juggling with the knees and a football control task. Implications for theory and practice are highlighted.     

Transfer and motor skill learning in association football

Transfer of learning involves the influence of previous experiences on the performance or learning of new skills. It is defined as a gain (or loss) in the capability for performance on one task as a result of practice on another. The aim of the study was to examine the degree of transfer between various association football skills. Twenty intermediate male players participated in the study. During pre- and post-training tests, participants juggled a football as many times as possible within 30 s using feet or knees. Further tests required participants to control an approaching football inside a restricted area using the preferred and non-preferred kicking leg. Following performance on the pretest, two matched skill groups were obtained. One group participated in a 4-week training period in which feet-only ball juggling was practised for 10 min daily, while the remaining group acted as a control. Trained participants exhibited superior post-test performance on knee juggling and ball control with preferred and non-preferred leg tasks relative to the control group (p< 0.05). Findings indicate positive transfer of learning from juggling practice with the feet to juggling with the knees and a football control task. Implications for theory and practice are highlighted.     

基于试验点自动识别的飞行试验智能化监控技术

试验点作为飞行试验任务的最小组成单元,明确了试验机所要完成的任务及要求,是飞行效果评估的主要依据。深入分析试验机在完成不同试验点时的参数变化特征,结合领域专家人工识别的先验知识,提取影响试验点识别的关键参数及其变化规律。构建试验点识别知识库,设计试验点自动识别算法。结合飞行试验实时任务评估技术,开发基于试验点自动识别与智能评估的飞行试验实时监控系统,实现了从"智能化安全监控"到"智能化任务监控"的转变,有效提升了试验机的试飞效率。