System Response Delay Research Articles

FPID-RCP: A Control Method for a Swing-Type Wave Compensation Platform System

With the rapid development of marine engineering in recent years, offshore operations have become increasingly common, making wave compensation platforms crucial for safe operations at sea. This paper presents a pendulum-type wave compensation platform specifically designed for wave compensation applications. The main components of this wave compensation platform include a chassis, support base, hydraulic cylinders, telescopic rods, upper platform, three sets of balancing mechanisms, three sets of tilt angle sensors, and a control system. Firstly, to thoroughly understand the compensatory motion of the pendulum-type three-degree-of-freedom wave compensation platform, kinematic analysis of the entire system was conducted, and the motion inverse solution curves of the mechanism were obtained through simulation using motion simulation software. Secondly, to enhance the compensatory response performance of the platform, a fuzzy PID control algorithm was employed to control the system and achieve attitude control of the platform. Finally, through control system simulation, compared to PID control, fuzzy PID reduces system response delay and successfully meets the expected technical requirements and application needs.

Variable-rate spray system for unmanned aerial applications using lag compensation algorithm and pulse width modulation spray technology

To ensure that a variable-rate spray (VRS) system can perform unmanned aerial spray in accordance with a prescription map at different flight speeds, we examine in this paper such significant factors as the response time of the VRS system and the pressure fluctuation of the nozzle during the variable-rate spraying process. The VRS system uses a lag compensation algorithm (LCA) to counteract the droplet deposition position lag caused by the system response delay. In addition, pulse width modulated (PWM) solenoid valves are used for controlling the flowrates of the nozzles on the variable-rate spray system, and a mathematical model was constructed for the spray rate (L min-1) and the relative proportion of time (duty cycle) each solenoid valve is open. The pressure drop and solenoid valve response time at different duty cycles (50%~90%) were measured by indoor experiments. Meanwhile, the lag distance (LD), spray accuracy, and droplet deposition characteristics of the VRS system were tested by conducting outdoor experiments at different flight speeds (4m s-1, 5m s-1, 6m s-1). The results show that LCA can effectively reduce the lag distance. The lag distance (LD) values of the VRS system with LCA ranged from -0.27 to 0.78m with an average value of 0.32m, while without LCA, the LD values increased to 3.5~4.3m with an average value of 3.87m. The overall spray position accuracy was in the range of 91.56%~97.32%. Furthermore, the spray coverage and deposition density, determined using water sensitive paper (WSP), were used to evaluate the spray application performance taking into account the spray volume applied. The VRS system can provide the most suitable spray volumes for insecticide and fungicide plant protection products. Based on a prescription map, the optimized VRS system can achieve accurate pesticide spraying as well as desirable spray coverage and deposition density.

Ibuprofen in the Management of Viral Infections: The Lesson of COVID-19 for Its Use in a Clinical Setting.

Nonsteroidal anti-inflammatory drugs (NSAIDs) are commonly used for the management of fever, pain, and inflammation. However, they have always been considered to have a double-faced role, according to their capacity to manage inflammation but also their possible reduction of immune system response and diagnosis delay. This last point could favor a dramatic increase of viral infection diffusion, possibly leading to a more severe outcome. The advent of severe acute respiratory syndrome coronavirus 2 excluded the use of NSAIDs, particularly ibuprofen, and then indicated this drug as the better NSAID to manage infected outpatients and prevent complications. Several authors described the role of NSAIDs and ibuprofen in preventing cytokine storm and modulating the immune system. However, the development of both adverse drug reactions (i.e., gastrointestinal, renal, hepatic, and cardiovascular) and drug interaction recalled the necessity of prescribing the better NSAID for each patient. In this narrative review, we describe the role of NSAIDs, particularly of ibuprofen, in the management of viral symptoms, suggesting that the NSAID may be chosen considering the characteristics of the patient, the comorbidity, and the polytherapy.

Trajectory Tracking of Autonomous Vehicle Using Clothoid Curve

This paper proposes a clothoid-curve-based trajectory tracking control method for autonomous vehicles to solve the problem of tracking errors caused by the discontinuous curvature of the control curve calculated by the pure pursuit tracking algorithm. Firstly, based on the Ackerman steering model, the motion model is constructed for vehicle trajectory tracking, Then, the position of the vehicle after the communication delay of the control system is predicted as the starting point of the clothoid control curve, and the optimization interval of the curve end point is determined. The clothoid control curves are calculated, and their parameters are verified by the vehicle motion and safety constraints, so as to obtain the optimal clothoid control curve satisfying the constraints. Finally, considering the servo system response delay time of the steering system, the steering angle target control value is obtained by previewing the curvature of the clothoid control curve. The field experiment is conducted on the test road, which consists of straight, right-angle turns and lane-change elements under three sets of speed limitations, and the test results show that the proposed clothoid-curve-based trajectory tracking control method greatly improved the tracking accuracy compared with the pure pursuit method; in particular, the yaw deviation is improved by more than 50%.

Cross-domain management system of real estate sales information based on blockchain

In the existing real estate sales information management system, the efficiency of information cross-domain management is low, and the information security is poor. The whole architecture of real estate sales information system includes sales information collection module, intelligent contract execution module and real estate information encryption module. The discrete wavelet transform method is used to fuse similar data, and the intelligent contract is designed according to the data fusion results, and all sales information is encrypted. Then the trust model of blockchain certificate authorisation centre is designed, and the final result is verified with real estate sales information access cross-domain authentication and real estate sales information cross-domain management system design. The experimental results show that the safety factor of the system data designed in this paper can reach 0.99, and the system response delay is about 0.5 s.

Research and Application of Cloud Platform-Oriented Intelligent Information Management System

In order to realize unified deployment and system planning of various types of information and diverse needs, the author proposes an educational information management platform using cloud computing technology. The author introduces the layered architecture and platform advantages of cloud computing technology. Combining the advantages of cloud computing technology with the characteristics of the construction of educational information management platforms in colleges and universities, the B/S architecture is established, and the architecture model of the educational information management platform based on cloud computing technology is designed; the model includes user access layer, SaaS layer, PaaS layer, and IaaS layer, then analyze the functional modules of the platform design. Based on the Linux operating system server terminal, using Apache as the Web application server, the JSP system page was developed and established a SQL Server database, which includes information tables such as users, departments, teachers, courses, teaching resources, and statistical analysis. Finally, the application effect of the education information management platform based on cloud computing technology is analyzed. Experimental results show that the platform was tested, and it was found that the accuracy of system data operation was greater than 90%; the system ran stably and smoothly for more than 2 hours; 200 people could use the system at the same time; the system response delay was less than 3 seconds. Conclusion. The educational information management platform can be user-oriented, meet the personalized application needs of teachers and students in schools, and provide strong technical support for teaching experience innovation.

Review and Comparison of Clearance Control Strategies

The nonlinearity of clearance has a significant influence on the performance of a system while ensuring the reliability of the variable-speed transmission, and hinders the development of the controlled object according to the predetermined trajectory. Aimed at the transmission clearance problem in different systems, this study summarizes the existing literature and provides a reference for the research and compensation of clearance characteristics. First, the influence of clearance on system performance is analyzed and summarized, and it is shown that the existence of clearance causes problems, such as system response delay and limited cycle oscillation. Then, the control strategies for studying clearance are introduced, which are mainly divided into the control strategy based on the clearance model and the non-clearance model control strategy, and these are respectively explained. Finally, some opinions are proposed for the perfection and development of future clearance nonlinear control theory. Ideas for realizing the suppression of the adverse effects of clearances have their characteristics, and in practical applications, the difficulty of implementation and cost control should be comprehensively considered. In the future, to cope with complex and changeable environments, the clearance control strategy will continue to be optimized.

Time-delay characteristics of air-conditioning system for subway trains

The time-delay characteristic of the air-conditioning system is the basis of predictive control of the air-conditioning system. The time-delay of the subway train's air-conditioning system can be divided into system response delay and carriage temperature change delay. Among them, the system response delay can be divided into two stages. The first stage is when the cooling load enters the carriage to the air-conditioning system starts to adjust; the second stage is when the air-conditioning system starts to adjust to the carriage temperature starts to decrease. In this study, the time-delay characteristics of the subway train's air-conditioning system are studied by numerical simulation and mathematical derivation. The accuracy of the calculation model was verified by comparing it with the field measurements data. Then, the influence of various factors on the time-delay characteristics of the air-conditioning system are analyzed. The results indicated that the system response delay time of the subway train's air-conditioning system increases exponentially with the instantaneous cooling load change and decreases linearly with the carriage design temperature. Moreover, the carriage temperature change delay of the air-conditioning system is related to the train carriage volume and temperature, the supply air volume and temperature, and the instantaneous cooling load change. However, the influence of the carriage and the supply air temperature on the carriage temperature change delay is minimal. Especially in the constant air volume air-conditioning system, the carriage temperature change delay is mainly affected by the instantaneous cooling load change.

Assessment of the Response Time to Information Messages in the Conditions of a Farms Based on the Methodology of Real-Time Systems

As you know, modern farms equipp many technological devices, the operation of which directly affects the volume of agricultural products, the period of readiness, their quality, shelf life, etc., in this regard, the issues of assessing the response time and reaction to information flows are relevant. The article presents the results of constructing a model based on real-time systems for assessing system stability and the response time of a subject (farmer) to information messages from IoT devices to the subject’s smartphone, depending on the time of performing current, priority and critical technological operations, their relevance, as well as on the level of information noise and the availability of resources. The analysis of the model revealed that an increase in the number of control objects and information messages increases the system response delay time from 0 to 36.5 hours which will especially depends on the receipt of priority and critical messages. The article offers solutions to reduce the response time, in particular by dividing the message flow into production and personal, resource optimization, using digital technologies (IoT), databases and improving the information skills of farmers.

How latency, action modality and display modality influence the sense of agency: a virtual reality study

The objective of this study was to investigate the influences of latency (i.e., technical system response time), action modality (button press, voice command) and display modality (head-mounted display, monitor) on the sense of agency (SOA). SOA is the experience of controlling one’s own actions and their corresponding effects in the environment. The N = 31 (48% female, with a mean age of 24) participants had to interact repeatedly with three different objects (lamp, tablet and computer) in a virtual environment (presented on a monitor or via a head-mounted display) by using a voice command or pressing a button to turn the objects on. The objects reacted after a specific technical system response delay (150, 450 and 750 ms). Results showed that the SOA was weaker for actions employing voice commands opposed to button presses, except for the explicit SOA in the monitor condition. Higher latencies diminished the explicit, but not the implicit SOA. Neither the explicit nor the implicit SOA was significantly affected by the display modality. The findings in part support the weighting process of different agency cues of the underlying framework, and we propose to extend this model by a sense of presence. Users seem to react as if they have the impression that they are not able to control the technical system properly if they interact through a voice command. Therefore, human–computer interface designers could take account of our findings regarding the modality of an action by providing additional feedback cues to increase the SOA for interactions with voice interfaces.

Models of the effect of teleoperation transmission delay on robot movement time

Recent research of [Scholcover and Gillan (2018)] has shown experimentally that system transmission delay has a linear effect on the time taken to perform a complex tracking task with a simple teleoperated robot. This note shows that, for the case of moving a robot through a straight path, this relationship is predicted. The result is a simple modification of Drury’s law to take into account the system delay. This work extends the model for performance under intermittent illumination of Drury to the effects of fixed delays in task performance, occurring with teleoperated robots. In all cases, there was empirical evidence for the predicted linear relationship.Practitioner summary: When there is a delay in system response for robotic teleoperation between a control input and system output, movement time (MT) is increased and the increased times are linearly related to the system delay. This is true for zero and first-order control and for delays occurring before and after the control action.

Effects of system response delays on elderly humans\u2019 cognitive performance in a virtual training scenario

Observed influences of system response delay in spoken human-machine dialogues are rather ambiguous and mainly focus on perceived system quality. Studies that systematically inspect effects on cognitive performance are still lacking, and effects of individual characteristics are also often neglected. Building on benefits of cognitive training for decelerating cognitive decline, this Wizard-of-Oz study addresses both issues by testing 62 elderly participants in a dialogue-based memory training with a virtual agent. Participants acquired the method of loci with fading instructional guidance and applied it afterward to memorizing and recalling lists of German nouns. System response delays were randomly assigned, and training performance was included as potential mediator. Participants’ age, gender, and subscales of affinity for technology (enthusiasm, competence, positive and negative perception of technology) were inspected as potential moderators. The results indicated positive effects on recall performance with higher training performance, female gender, and less negative perception of technology. Additionally, memory retention and facets of affinity for technology moderated increasing system response delays. Participants also provided higher ratings in perceived system quality with higher enthusiasm for technology but reported increasing frustration with a more positive perception of technology. Potential explanations and implications for the design of spoken dialogue systems are discussed.

SIMPLE DATA APPROXIMATION FOR COMPUTER AND CONTROLLER-AIDED DEVICES

INTRODUCTION
 Development of mechatronic systems involves finding an optimal balance between the basic mechanical structure, sensor and actuator implementation, automatic information processing and overall control. Mechatronic systems are characterized by a combination of basic mechanical devices with a processing unit monitoring and controlling it via number of actuators and sensors. Therefore sensors are significant in the process of providing usable output to microcontrollers. Wide range of sensors are available for constructing mechatronic systems. Sensors can be divided into two big groups: Active and Passive. Other type of classification is by the means of detection used in the sensor. Some of the means are electric, chemical, radioactive etc. Various types of sensors are classified by their measuring objectives for example light sensors, temperature sensors, flow sensors etc.
 MATERIALS AND METHODS
 In the process of constructing a mechatronic system a proper setup and signal processing must be provided. There exist certain problems with several sensors, therefore sometimes additional circuits for signal conditioning are made to linearize the output with hardware, but some researchers and developers try to linearize the signal using software.
 In modern manufacturing equipment very complex systems of devices and sensors are made therefore, they must function correctly because they are the main control parameters. It is particularly important that such control parameters that bring about a correct actual behavior in relation to the reference behavior of such a system are available as a function of time. This means that the parameters must be such that the actual behavior of the system corresponds as closely as possible to the reference behavior. Some examples of such systems are:
 
 Robot arms, which move a tool, such as a laser or burr removing tool, for example, which is to be guided along a particulary contour line of a workpiece.
 Heating systems which are intended to impart a particulary temperature profile to a workpiece.
 
 The input data of sensors is crucial for mechatronic systems.
 A large part of the system is equipped with sensors that read the most important parameters – location coordinates, altitude, compass readings, distance to the barrier (for robots and unmanned aerial vehicles), temperature (heaters and coolers), lighting, etc.
 Often, some types of sensors give floating data, processing which, a computer or controller acting under an algorithm develops non-physical, inexecutable commands for the final control elements. This results in an increasing load of engines, heating elements, and other actuators, as well as inappropriately increasing energy consumption.
 The well-known PID algorithm and numerical approximation with built-in MatLab or MATCAD functions does not provide a solution for autonomous systems with controllers that have limited memory and speed of operation.
 RESULTS
 New methods that approximate sensor data and are applicable to both analogue and PWM (Pulse-Width-Modulation)-controlled devices have been developed in the paper.
 The first proposed – derivative - method relates to the restriction of the function direction coefficient module. The second method – the growth bisection method enables smooth sensor data to be obtained.
 The derivation method is based on limitation of the maximum function increment to a specified level. The growth bisection (proportional) method is based on comparison of the increment module with the increment in the previous step and its proportional decrease by multiplying by a predefined constant. Both methods take up some lines in the control program code, and most mechatronic equipment is capable of real-time operation.
 CONCLUSIO
 Dynamic data background connection allows to obtain a self-learning system adapting to the nature of incoming data – a higher number of data will be used in case of minor changes; in contrast, only the last data saved will be used for a rapid change. A system response delay is negligible.

Delay-dependent stability and added damping of SDOF real-time dynamic hybrid testing

It is well-recognized that a transfer system response delay that reduces the test stability inevitably exists in real-time dynamic hybrid testing (RTDHT). This paper focuses on the delay-dependent stability and added damping of SDOF systems in RTDHT. The exponential delay term is transferred into a rational fraction by the Pade approximation, and the delay-dependent stability conditions and instability mechanism of SDOF RTDHT systems are investigated by the root locus technique. First, the stability conditions are discussed separately for the cases of stiffness, mass, and damping experimental substructure. The use of root locus plots shows that the added damping effect and instability mechanism for mass are different from those for stiffness. For the stiffness experimental substructure case, the instability results from the inherent mode because of an obvious negative damping effect of the delay. For the mass case, the delay introduces an equivalent positive damping into the inherent mode, and instability occurs at an added high frequency mode. Then, the compound stability condition is investigated for a general case and the results show that the mass ratio may have both upper and lower limits to remain stable. Finally, a high-emulational virtual shaking table model is built to validate the stability conclusions.

GP preferences for information systems: conjoint analysis of speed, reliability, access and users

To elicit the preferences and trade-offs of UK general practitioners about key features of health information systems, to help inform the design of such systems in future. A stated choice study to uncover implicit preferences based on a binary choice between scenarios presented in random order. were all 303 general practice members of the UK Internet service provider, Medix who were approached by email to participate. The main outcome measure was the number of seconds delay in system response that general practitioners were willing to trade off for each key system feature: the reliability of the system, the sites from which the system could be accessed and which staff are able to view patient data. Doctors valued speed of response most in information systems but would be prepared to wait 28 seconds to access a system in exchange for improved reliability from 95% to 99%, a further 2 seconds for an improvement to 99.9% and 27 seconds for access to data from anywhere including their own home compared with one place in a single health care premises. However, they would require a system that was 14 seconds faster to compensate for allowing social care as well as National Health Service staff to read patient data. These results provide important new evidence about which system characteristics doctors value highly, and hence which characteristics designers need to focus on when large scale health information systems are planned.

Chronism Theory, Culture, and System Delay

System response delay has been cited as the single most frustrating aspect of using the Internet and the most worrisomeaspect of Web application design. System response time (SRT) research generally concludes that delay should be eliminated where possible to as little as a few seconds, even though delay reduction is costly. Unfortunately, it is not clear if these conclusions are appropriate outside of the developed world where nearly all of the SRT research has taken place. Cultural effects have been, hence, generally missing from SRT research. The one SRT study to date outside of the developed world did report differences using the theoretical construct of cultural chronism, and this finding could limit the generalizability of SRT research findings from developed countries to many economically developing nations. However, limitations and potential confounds in this single study render those findings tentative. The end of Apartheid in South Africa allowed an opportunity to conduct a longitudinal free simulation experiment that overcomes the critical limitations of this previous research. Subjects were members of historically polychronic and monochronic groups who had been segregated by Apartheid and now live in an integrated society with shared infrastructure and computer access. Results find that members of the historically polychronic group are more accepting of longer delays and are more willing to trade longer delays for improved functionality than are their historically monochronic counterparts. Furthermore, tests find that members of the historically monochromic population that came of age in a desegregated, majority-polychronic culture appear to be polychronic themselves and to differ significantly from the older monochronic generation. Results from this study can be applied to design culturally sensitive applications for users in the developing economies of the world.

The Influence of Image Feedback Delay and System Response Delay on the Video Mirror Interface with the Touch Action

The Influence of Image Feedback Delay and System Response Delay on the Video Mirror Interface with the Touch Action

On-chip microdialysis system with flow-through sensing components

Microdialysis probes have been used for diabetes treatment as continuous monitoring system coupled to a glucose sensor. An on-chip microdialysis system with in-line sensing electrodes is demonstrated. As a first step towards greater biosensor integration with this miniaturized microdialysis system, a stacked system with in-line sensing electrodes was developed. Impedance electrodes sputtered within the microchannels were used to determine fluid electrical resistance from a dialyzed phosphate buffered saline (PBS) solution, which characterizes solution conductivity as a function of PBS concentration. The permeability of the membrane to the salt ions was obtained as 0.246 ± 0.028 μm/s (15 nm pores). Subsequently, experiments measuring PBS dialysis in the time-domain at 64.4% recovery were conducted. The PBS concentration of the reservoir was changed in both a step response and sinusoidally with an 800 s period. The subsequently measured impedance indicates that the system is able to continuously track concentration changes in the reservoir with a 210 s system response delay. Most of this delay is due to the dead volume within the tubing between the syringe pumps and the microsystem. In addition, the predicted response was modeled using linear systems theory and matches the experimental measurements ( r = 0.98). This system is expected to have the proper sensitivity to track physiologically relevant concentration changes of biomolecules such as glucose (which has a physiological maximum change rate of ∼4 mg/dl min with a periodicity of 1 h or greater) with minimal lag time and amplitude reduction.

Considerations for the development of real‐time dynamic testing using servo‐hydraulic actuation

AbstractThis paper presents a study of the use of servo‐hydraulic systems in the implementation of real‐time large‐scale structural testing methods in force control such as effective force testing (EFT) and in displacement control such as real‐time pseudodynamic testing (RPsD). Mathematical models for both types of control systems are presented and used to investigate the influences of servo‐systems on the overall system performance. Parameters investigated include the overall system dynamics, nonlinearities of servo‐systems, actuator damping, system mass including piston mass, and system response delay. Results of both numerical simulations and experiments showed that many of the influences of the servo‐hydraulic system that significantly affect the real‐time dynamic tests can be properly compensated through control schemes identified in this paper. Copyright © 2003 John Wiley & Sons, Ltd.

Lake sediments, erosion and landscape change during the Holocene in Britain and Ireland

Lakes are excellent repositories of air-borne and especially stream-borne materials. It has long been recognised that lake sediments contain a strong record of catchment soils via the inputs of minerogenic and chemical erosional products. To these may be added a variety of palaeoecological indicators including pollen, fungi, Sphagnum leaves and faunal remains. Pollen analysis, in particular, enables land use change to be assessed over many millennia and demonstrates the landscape impacts of woodland clearance, grazing and crop cultivation. Radiocarbon dating provides a chronology for environmental and agricultural change and acts as an indicator of erosion in its own right. The use of such indicators to reconstruct past instances and patterns of erosion is demonstrated with reference mainly to 50 British and Irish lake sites and especially those which have produced signals of erosion in the form of accelerated sediment accumulation and inversed or reversed sequences of radiocarbon dates during the mid and late Holocene. Sites displaying even or decreased sedimentation through time are concentrated in northern and northwestern Scotland and have either no clear signs of human impact, or only so towards the latter part of the Holocene. This pattern probably reflects a combination of factors including low population densities, thin soils and the ‘sealing’ effect of blanket peat. In contrast, all sites with accelerated erosion have indications of anthropogenic impact. This is often prior to levels of increased sedimentation showing a delay in system response. While the spread of dates for the start of the rise in sediment accumulation spans 6200–940 BP, three clusters are evident at 5295–4970, 4530–4235 and 2980–2810 BP. Radiocarbon inversions (mostly reversals) are evident for 18 sites. No obvious causal patterning is indicated and they probably demonstrate no more than the fact that catchment soils, including peats, around a particular site were pushed beyond an erosional threshold sufficient to ‘age’ the sediments deposited within the lakes. It is hoped that improvements in data quality will allow the refinement of such exercises in the future and that lakes will be valued as repositories of long-term landscape sensitivity.