Extending UML-RT for Control System Modeling

In model based approaches for real-time systems (RTS) development, an iterative process that consists in the early stage verification of real-time constraints fulfillment according to a given design is usually performed in order to detect as early as possible unfeasible designs. Schedulability analysis allows this early verification of timing constraints according to so called Schedulability Analysis Model (SAM). This paper proposes a configurable framework for implementation synthesis of component oriented specification that is able to preserve the SAM timing properties that are validated at an early stage of the RTS design.

The tax big data supervision system and method, including the distributed real-time management and control system deployed in the superior unit and each subordinate unit, the superior distributed real-time management and control system is used to receive the management and control rules, and issue the management and control rules to the subordinate distributed real-time management and control System: The distributed real-time management and control system writes the massive data in the data source at the same level into the distributed message queue Kafka in real time, and uses the distributed stream computing engine Flink to compare and calculate based on the management and control rules, and write the data that conforms to the management and control rules. Enter the alarm information into Kafka; the lower-level distributed real-time management and control system pushes the alarm information in the Kafka subscription at this level to Kafka in the upper-level distributed real-time management and control system; the upper-level distributed real-time management and control system pushes the alarm information in the Kafka subscription to users , at the same time push the alarm information to the distributed search engine ElasticSearch to save, and provide the historical alarm information query function.

Gear factories are most typical discrete manufacturing factories. Many gear factories are striving to explore how to achieve intelligent manufacturing in order to improve efficiency and reduce costs. Digital twin technology is currently one of the most reliable ways to achieve intelligent manufacturing. This article aims to establish a real-time control system in order to promote intelligent manufacturing for discrete manufacturing factories. Firstly, a model for a digital twin gear factory is put forward based on the characteristics of gear factories, and the composition of a real-time control system for gear factories is clarified. Then, a human–computer interaction architecture for the real-time control system is proposed. The real-time control system consists of three parts as follows: a monitoring module, a virtualizing module, and a controlling module. At work, it appears as a kind of human–machine interaction form with the three following interfaces: a monitoring window, a virtualizing window, and a controlling window. Finally, a gear factory, which is specialized in manufacturing the intermediate shaft dual gear of a new energy vehicle gearbox, develops a set of software for the real-time control system. The prototype software is obtained through some development activities such as 3D MAX and WebGL virtualization modeling and OPC UA and REST communication design.

In the current work, an approach to implement AI-based techniques in real-time focusing mainly on the detection, tracking, and landing on the target object is presented. For an object detection, CNN algorithm is utilized. For object tracking and stabilizing, a novel algorithm is developed that can execute along with object detection via sequential stream data. For landing, a vision-based algorithm is used to estimate the distance between the UAV and the detected object. For UAV control, a Fuzzy-PID controller is designed to steer the UAV by a continuously manipulation of the actuators based on the stream data from the tracking unit and dynamics of the UAV. For UAV landing, a new type of fuzzy logic controller is developed to compensate for the nonlinear ground effect that affects the safe landing of the UAV. All the developed algorithms are executed on an NVIDIA Jetson TX2 embedded artificial intelligence device, and an ARM Cortex M4. Experimental results show that the tracking algorithm responds faster than conventionally used approaches, and the safe landing algorithm minimized the landing time of the UAV and provided the safety assurance as compared to conventional controllers. Furthermore, a farming monitoring and automated wireless charging is considered as an application example.

The Multithreaded Application Real-Time executor (MARTe) is a data driven framework environment for the development and deployment of real-time control algorithms. The main ideas which led to the present version of the framework were to standardize the development of real-time control systems, while providing a set of strictly bounded standard interfaces to the outside world and also accommodating a collection of facilities which promote the speed and ease of development, commissioning and deployment of such systems. At the core of every MARTe based application, is a set of independent inter-communicating software blocks, named Generic Application Modules (GAM), orchestrated by a real-time scheduler. The platform independence of its core library provides MARTe the necessary robustness and flexibility for conveniently testing applications in different environments including non-real-time operating systems. MARTe is already being used in several machines, each with its own peculiarities regarding hardware interfacing, supervisory control configuration, operating system and target control application. This paper presents and compares the most recent results of systems using MARTe: the JET Vertical Stabilization system, which uses the Real Time Application Interface (RTAI) operating system on Intel multi-core processors; the COMPASS plasma control system, driven by Linux RT also on Intel multi-core processors; ISTTOK real-time tomography equilibrium reconstruction which shares the same support configuration of COMPASS; JET error field correction coils based on VME, PowerPC and VxWorks; FTU LH reflected power system running on VME, Intel with RTAI.

Fuzzy controllers are used in many applications because of their rapid design by translating heuristic knowledge, robustness against perturbations, and smoothness in the control action. It is known that as the number of membership functions increases fuzzy control becomes smoother. However, since the number of rules is an exponential function of the number of inputs and number of membership function, the methodology is difficult to implement when the number of rules is very large. To overcome such a limitation, this paper proposed an information fusion based fuzzy control algorithm, which fuses the angle and velocity as one input to reduce the complexity of the controller and enhance the robustness. By doing so, the fuzzy controller is simplified and the RAM memory requirements are reduced. In order to test the performance of the proposed algorithm, a DSP based rapid control prototyping system is also developed to facilitate the development of real-time control system. Real-time control experiments with Quanser's rotary inverted pendulum demonstrated the efficiency of the designed fuzzy controller embedded into a stand-alone processor based on a fixed-point DSP.

For regular vehicles, the vibration generated when a vehicle passes through a groove or step is dampened but still remains and causes whole-body vibration (WBV) to occupants through vehicle seat. Several epidemiological studies have clearly demonstrated that prolonged exposure to vibration from vehicles is detrimental to human health and may cause motion sickness. To reduce this whole-body vibration. We designed a simple and effective feed-forward control system with compact actuator compatible to the limited under-seat dimension and power outlet of compact general passenger cars and successfully authenticated the possibility of vertical vibration reduction by controlling the vehicle seat surface vertical displacement. In this research, we designed a real-time feed-forward control system with transfer function model estimation. This real-time control system contains a commercial DSP device providing coherence input and output with a controllable delay. With the application of transfer function model and state space model, this system successfully estimated the upcoming vibration acceleration according to the input of the vibrational acceleration time-domain data acquired from lower arm when the test vehicle passing a step. Furthermore, it is possible to process the input data and control the linear actuator precisely to reduce the vertical impact observed as setting force reduction.

Voting is an important operation in multichannel computation paradigm and realization of ultrareliable and real-time control systems that arbitrates among the results of N redundant variants. These systems include N-modular redundant (NMR) hardware systems and diversely designed software systems based on N-version programming (NVP). Depending on the characteristics of the application and the type of selected voter, the voting algorithms can be implemented for either hardware or software systems. In this paper, a novel voting algorithm is introduced for real-time fault-tolerant control systems, appropriate for applications in which N is large. Then, its behavior has been software implemented in different scenarios of error-injection on the system inputs. The results of analyzed evaluations through plots and statistical computations have demonstrated that this novel algorithm does not have the limitations of some popular voting algorithms such as median and weighted; moreover, it is able to significantly increase the reliability and availability of the system in the best case to 2489.7% and 626.74%, respectively, and in the worst case to 3.84% and 1.55%, respectively.

We have designed an active stressed lap and its control mode is that an computer sends control orders to the control system of the active stress lap, under windows operating system. The control mode has a shortage, which is a limit exists when we use the lap to complete an aspheric surface deformation task with a fast focal ratio, because windows system is not real-time. Therefore, we have designed a real-time deformation control system for the active stressed lap. The paper makes an introduction to the structure of the deformation control system of the active stressed lap. Secondly, gives a detailed presentation on the design of the test system from software and hardware two aspects .Finally, the paper makes a dynamic response test on the deformation control system of stressed lap, a stability test on the control system and an overall performance test.

Based on the knowledge rule models and the analysis mathematical models, the two-level real-time expert control system (ECS) was established. With the self-learning ability in expert optimal mode, the expert system (ES) was developed to find the calcining zone's optimal temperature value. To optimize the process, the real-time control system (RTCS) was designed to realize the control of the feeding capacity and negative pressure by self-adjusting algorithm based on CARMA module and least square method. At present, the system was started to work on the stream, and the long-term application shows that it has high reliability and good practicability. Besides, the process and the product quality are developed, and the power is economized.

In this paper we present the architecture and framework for a benchmark suite that has been developed as part of the DeSiDeRaTa project. The benchmark suite is representative of the emerging generation of distributed, mission-critical, real-time control systems that operate in dynamic environments. Systems that operate in such environments may have unknown worst- case scenarios, may have large variances in the sizes of the data and event sets that they process (and thus, have large variances in execution latencies and resource requirements), and may be very difficult to characterize statically, even by time-invariant statistical distributions. The benchmark suite (called DynBench) is useful for evaluation of the Quality of Service (QoS) management and/or Resource Management (RM) services in distributed real-time systems. As such, DynBench includes a set of performance metrics for the evaluation of the QoS and RM technologies in dynamic, distributed real-time systems. The paper demonstrates the successful application of DynBench in evaluation of the DeSiDeRaTa QoS management middleware.

In this paper, we present our experience on integrating timing constraint verification and analysis, by using the real-time scheduling theory, in an industrial context. The verification process has been integrated into a design flow at THALES Communications & Security. We focus our work on Software Radio Protocols (SRP). We have used Model-Driven Engineering technologies and the Cheddar schedulability analysis tool for our experiment. We show how we have modeled a complete SRP in UML MARTE, a profile for real-time embedded systems, before using model transformation to extract information for schedulability analysis with Cheddar.

A development process for safety-critical real-time computer systems has to emphasize the importance of time. On the one hand, such a development process has to be based on hardware and software technology that supports predictability in the time domain. On the other hand, the development process has to provide tools for assessing and verifying the correctness of the timing of both the hardware and the software components of the real-time systems being developed. Together with schedulability analysis, Worst-case execution time analysis (WCET analysis) forms the basis for establishing confidence into the timely operation of a real-time system. WCET analysis does so by computing (upper) bounds for the execution times of the tasks in the system. These bounds are needed for allocating the correct CPU time to the tasks of an application. They form the inputs for schedulability tools, which test whether a given task set is schedulable (and will thus meet the timing requirements of the application) on a given target system. While schedulability analysis is one of the traditional fields of investigation in real-time systems research, WCET analysis caught the attention of the research community only about ten years ago (Kligerman and Stoyenko, 1986; Mok et al., 1989; Puschner and Koza, 1989; Shaw, 1989). In the last decade, however, more and more research groups started to put a focus on WCET analysis. As a result, substantial progress has been made in this area in a relatively short time. After ten years of research in the field, it is appropriate to have a special issue on WCET analysis. It is the goal of this special issue to review the achievements in WCET analysis and to report about the recent advances in this field. In the following section we will define the problem area of WCET analysis and thus clarify the issue WCET analysis is dealing with— still many people mix up execution-time analysis and response-time analysis. We will then summarize the subproblems of WCET analysis and provide an overview of previous contributions to the state of the art in this field. At the end of the introduction we will give an overview to the research papers that have been selected for this special issue.

Due to demands for higher levels of automation from systems, the use of hierarchical and distributed control systems that integrate estimation, prediction, control, fault tolerance, adaptation, learning, etc., into one framework is becoming widespread. Specific applications that use complex control of this sort include robots, manufacturing and automation systems, automated highway systems (AHS), and other intelligent vehicles. Here, we study the use of the Real-Time Control System (RCS) software library, developed by the Intelligent Systems Division (ISD) at the National Institute of Standards and Technology (NIST) for the design and implementation of such complex control systems. We examine the theory behind both the development and implementation, and provide a physical implementation example (a process control problem) and a conceptual example of how to use RCS in the design of a hierarchical controller for an AHS.

System monitoring for a real time local area network