Multi-task Scheduling Research Articles

Intelligent domestic electricity management system based on analog-distributed hierarchy

Electricity management system has been extensively investigated for efficiently monitoring and controlling domestic power. Nevertheless, the existing designs are generally rough, inflexible and complex, which leads to poor convenience in practice use and performance evaluation. In this paper, a systematic structure of intelligent electricity management system is firstly constructed and then corresponding multi-task scheduling algorithm based on embedded system is proposed for facilitating domestic power management. The proposed architecture accomplishes the system functions on two interactive modules. And this architecture is very beneficial to effective operation and intelligent management. Furthermore, real-time performance of the presented scheduling scheme is researched by a constraints model and the corresponding simulation result shows a good performance, where the overtime ratio is 10.3% under an extremely bad condition. Besides, the relationship between overtime ratio and sporadic tasks is derived in a general way and also verified by simulation.

Intelligent Improvement in Multi-Task Data Acquisition System Employing Low Cost Embedded Web Server

based user interfaces are state-of-the-art in network- based embedded systems. These Web-based user interfaces makes configuration, control and monitoring of a device from every PC, smart phone or tablet device running a Web browser possible. This paper proposed the design and development of on-line Interactive Data Acquisition and Control System (IDACS) using an ARM based embedded Web server. As a result, this provides a need for Web services being deployed on various embedded processors such as Advanced RISC Machine (ARM). Single chip IDACS improves processing capabilities and rectifies the problem of poor reliability in real time context. This system uses ARM9 Processor, which is a real time processor that handles various processes based on multi tasking and reliable scheduling mechanisms. Web server application is ported into an ARM processor using Visual Basic, Web pages are written by Visual Studio; it is beneficial for real time IDACS, Mission critical applications, ATM networks, Power plants.

Operating System Support for IPNoSys


 
 
 The IPNoSys is an architecture that exploits the advantages of NoCs as parallel communication, reusability and scalability to transform the routers in processing elements building a packet-driven architecture that processing while routing the packets. This represents a paradigm break of traditional NoC-based MPSoC systems, which there is the separation between computation and communication. With new paradigm, such architecture already showed superiority in execution time comparing to an equivalent MPSoC. In this paper is presented the operating system support for IPNoSys, including the memory management, process management, I/O management, interruption, exception and timer. Additionally, it is proposed two versions of multi-task scheduling, the first one is a preemptive and the second a non-preemptive. In some cases the scheduling algorithms improvement the throughput of system up to 80%.
 
 

Communications Satellite Multi-Satellite Multi-Task Scheduling

Through research in task scheduling of related field domestic and overseas, this paper analyzes communication satellite tasks constraints based on task scheduling characteristics, such as communication tasks, satellite resources, time window constraints etc. The multi-satellite multi-task scheduling optimization model is established on the basis of dynamic constraint satisfaction problem (DCSP), meanwhile we build objective function and mathematic model. This paper develops a modified local change algorithm for the scheduling model. Compared with greedy algorithms and constraint propagation model by examples, the effectiveness of the proposed scheduling model was proved.

Finite State Machine to Optimize Multi-Tasking Concurrence Technology for Real Time Operating System

An new approach to multi-task programming using Finite State Machine (FSM) integrated with the multi-task concurrence schedule mechanism of embedded real time operating system was proposed in this paper. Detailed procedures of the approach and two years’ application in an urban heating network were also presented. The approach exhibits a promising prospect in those industrial control systems where more than one highly demanding real-time task are controled concurrently. Both the calls between tasks and the internal state transitions are implemented in the form of concurrent, so that the efficiency of CPU is increased with reasonable arrangement and configuration of CPU.

A Method for Scheduling Receiver Tasks Based on Maximum Allowed Execution Time Dichotomy Search

In designing and developing navigation receiver embedded software, the correct scheduling of navigation tasks is critical for ensuring that a receiver works in the right way. If a receiver's timing scheduling becomes abnormal, it may lead to timing conflicts of the multi-tasking navigation receiver, which may seriously influence the system's performance of real-time features and functionalities. This paper models the timing scheduling of navigation receivers by extracting all important timing parameters including the execution time, period, deadline and priority etc., and focusing on the execution time. The maximum execution time of a navigation task relies on the design and implementation algorithms and the computing capability of the processor. The execution time parameter can be properly adjusted in receiver software design or even in the phase of the receiver requirement changes. On the other hand, the other parameters (i.e., the period, deadline and priority) mainly depend on the receiver's technical requirements, and usually these parameters are set to constant values. In this research, a novel off-line method based on the maximum allowed execution time dichotomy optimization is proposed, and the equilibrium rule is proposed to apply to the multi-task maximum allowed execution time dichotomy search and an analysis of time series of those parameters obtained from real observations of receiver tasks was also conducted. Results indicate that the relative equilibrium is more suitable to the multi-task scheduling of receiver navigation, compared to the absolute equilibrium. The proposed method provides a fast off-line scheduling approach for the top level task design of navigation receivers, and remarkably improves the development efficiency of receiver embedded software.

The Integrated Design of an Interactive Service Robot for Shanghai World Expo 2010

This paper describes the integrated design and techniques of the HAIBAO robot, an interactive service robot developed for Shanghai World Expo 2010. Compared with previous exhibition service robots, the HAIBAO robot has improved flexible motion ability, anthropomorphic interaction ability and intelligent cognitive and decision-making ability. In addition to both hardware and software system design, some key techniques including a four-wheeled omnidirectional mechanism and its motion control and compensatory algorithm, and multitask scheduling are introduced. During the Expo, which lasted 184 days, 37 HAIBAO robots successfully served tourists by providing information, photography services, hall guidance, conversation and various entertainment. Their robustness, stability, flexibility and friendliness were greatly commended.

Research on Multitask Collaborative Scheduling Problem with Heuristic Strategies

According to problems existed in the current farm machinery scheduling process, a new farm machinery scheduling scheme is adopted in this dissertation. The collaborative scheduling model of farm machinery is established and multitask collaborative scheduling algorithm is designed through analyzing the differences between Vehicle Scheduling Problem and agricultural machinery scheduling in the dissertation. Earliest Start Time First and minimal resource allocated capacity first strategies are used in the farm machinery scheduling. The algorithm is useful for the case of machinery owner with sufficient farm machinery. The experiment proves that the collaborative scheduling algorithm is more effective than the serial scheduling algorithm.

Software Design of Aircraft Electrical Load Management Center Based on μC/OS-II

This paper introduces that embedded real time operating system μC/OS-II is applied in software design of aircraft electrical load management center. Firstly, the μC/OS-II and its running on ARM are briefly presented. Then the method of two system running modes is given in details. And the tasks assignment, priority allocation and communication between tasks under both two modes are also provided. Results show that multitask schedule managements of real-time system has solved the problem of poor real-time in a single task system. And the reliability of the system has been greatly improved.

Research and Development on Safety Monitoring Network System for Electric Locomotive Servicing Work

A safety network system is designed based on PROFIBUS-DP field bus, according to actual servicing work situation and control requirements for electric locomotive servicing work. The system realizes communication between first class master station and third equipment through using PROFIBUS-DP bus protocol. It also realizes interactive operation between slave station and non-contact IC card, meanwhile, slave station and MCU system. In addition, this article has analyzed the multi-task scheduling mechanism and data communication security on monitoring network system in detail as well. Results show that the system has higher application value through entire debugging and testing on network control system.

Design of Weld Seam Tracking Control System Based on DSP

In the process of weld seam tracking, traditional mathematical model of classical and modern control theory is hard to meet the requirement of high performance controller. This article based on the embedded digital signal processor DSP-TMS320F2812 for the field of industrial automation control.The fuzzy control technology is applied to real-time welding seam-tracking system, according to the F2812 which has the characteristics of real-time multitasking scheduling of resources and then designed the real-time control value adjustment Fuzzy-PI control system. The designed DSP real-time fuzzy control system gives full play to powerful control and signal processing ability of F2812, it can fully adapt for the controlling requirement of super-speed and high-precision.

Study on Data Mining System Multi-Task Scheduling Method Based on Precedence Constraints

Data Mining system has a large number of data processing tasks. This paper mainly studies on task scheduling problem which takes the minimum total completion time based on the m equivalent processors and n tasks with priority. Firstly, we propose a data mining system multi-task scheduling model. Secondly, we adopt genetic algorithm solving this model. Due to initial seed may not be satisfied with the precedence constraint, this paper uses the inverse adjacency list to modify. Finally, we show this model and its algorithm are feasible and valid by the simulation experiment.

Task Scheduling of Product Development Process Based on Complex Features of Web

Multi-task scheduling networkis extended based on the complex network theory, from new angles and perspectives to study the multi-task scheduling. The description of method and related mathematical models of complex and multi-task directed network aregiven. Combined with topology of the product development process and their own characteristics,the evaluation model and algorithmto describe the importance of the event node are presented. It can assess the nature ofdifferent nodes effectively, including the key nodes, at the same time,the scheduling algorithm based on the importance of active nodes hasbeen proposed.The study has a certain significance toarrange the execution of tasksin complex product development process reasonably and realize optimal allocation of manufacturing resources.

Development of CNC System for Machining of Grooves in Automobile Synchronization Regulators Sleeve

On the basis of analyzing the shortcomings of the current technics for grooves machining, this paper deals with the development of Numerical Control System for machining of grooves in automobile synchronization regulator sleeve, which holds first-rate technics. In order to improve efficiency and precision of grooves machining and reduce cost of the cutter, Hypocycloid-based technique together with interpolation is introduced and studied. With IPC as system platform and PMAC (Programmable Multiple-Axes Controller) as the controlling center of the system, the open architecture of “PC-Based” is used in the CNC system and the framework of the CNC hardware is developed. According to the ideas of modularization and real-time multi-task scheduler, the CNC software system is carved into many modules and the framework of the CNC software is developed.

Diesel hybrid electric vehicle hardware system

A controller for a diesel hybrid electric vehicle based on a V-cycle development approach is investigated in this paper. The hardware and infra program of the Hybrid Control Unit (HCU) are discussed in detail. The hardware system is designed based on circuit simulation; while the infra system is written with assemble language. Time sharing mode, buffer sharing mode and multi-task schedule method are used to ensure real-time communication in the infra program design. Based on multi-thread technology, hardware in loop test system is also designed. The hardware in loop and bench tests show that the controller could meet the requirements of the hybrid electric vehicle (HEV) and communicate in real-time. Circuit simulation, HCU, infra program and hardware in loop test form the effective V-cycle development platform to design a hardware system for a diesel HEV controller.

Development of Wireless Brain Computer Interface With Embedded Multitask Scheduling and its Application on Real-Time Driver's Drowsiness Detection and Warning

Biomedical signal monitoring systems have been rapidly advanced with electronic and information technologies in recent years. However, most of the existing physiological signal monitoring systems can only record the signals without the capability of automatic analysis. In this paper, we proposed a novel brain-computer interface (BCI) system that can acquire and analyze electroencephalogram (EEG) signals in real-time to monitor human physiological as well as cognitive states, and, in turn, provide warning signals to the users when needed. The BCI system consists of a four-channel biosignal acquisition/amplification module, a wireless transmission module, a dual-core signal processing unit, and a host system for display and storage. The embedded dual-core processing system with multitask scheduling capability was proposed to acquire and process the input EEG signals in real time. In addition, the wireless transmission module, which eliminates the inconvenience of wiring, can be switched between radio frequency (RF) and Bluetooth according to the transmission distance. Finally, the real-time EEG-based drowsiness monitoring and warning algorithms were implemented and integrated into the system to close the loop of the BCI system. The practical online testing demonstrates the feasibility of using the proposed system with the ability of real-time processing, automatic analysis, and online warning feedback in real-world operation and living environments.

UbiFOS: A Small Real-Time Operating System for Embedded Systems

The ubiquitous flexible operating system (UbiFOS) is a real-time operating system designed for cost-conscious, low-power, small to medium-sized embedded systems such as cellular phones, MP3 players, and wearable computers. It offers efficient real-time operating system services like multi-task scheduling, memory management, inter-task communication and synchronization, and timers while keeping the kernel size to just a few to tens of kilobytes. For flexibility, UbiFOS uses various task scheduling policies such as cyclic time-slice (round-robin), priority-based preemption with round-robin, priority-based preemptive, and bitmap. When there are less than 64 tasks, bitmap scheduling is the best policy. The scheduling overhead is under 9 µs on the ARM926EJ processor. UbiFOS also provides the flexibility for user to select from several inter-task communication techniques according to their applications. We ported UbiFOS on the ARM9-based DVD player (20 kB), the Calm16-based MP3 player (under 7 kB), and the ATmega128-based ubiquitous sensor node (under 6 kB). Also, we adopted the dynamic power management (DPM) scheme. Comparative experimental results show that UbiFOS could save energy up to 30% using DPM.

Multitask scheduling in networked control systems with application to large scale vehicle control

Aiming at scheduling problems of networked control system (NCS) used to fulfill motion synthesis and cooperation control of the distributed multi-mechatronic systems, the differences of network scheduling and task scheduling are compared, and the mathematic description of task scheduling is presented. A performance index function of task scheduling of NCS according to task balance and traffic load matching principles is defined. According to this index, a static scheduling method is designed and implemented to controlling task set simulation of the DCY100 transportation vehicle. The simulation results are applied successfully to practical engineering in this case so as to validate the effectiveness of the proposed performance index and scheduling algorithm.

Dynamic voltage scaling for real-time multi-task scheduling using buffers

This paper proposes energy efficient real-time multi-task scheduling (EDF and RM) algorithms by using buffers. The buffering technique overcomes a drawback of previous approaches by utilizing the slack time of a system fully. It increases the CPU utilization and averages the workload of a system, so it enhances the effectiveness of the DVS technique. We target multimedia applications where a slight buffering delay is tolerable within a latency constraint. We modify the state transition and queue handling mechanism of multi-task scheduling in the kernel. In experiments, our algorithms achieve up to 44% of energy consumption saving for EDF scheduling and 49% for RM scheduling with realistic task set configurations and reasonable machine specifications.

Concurrent reasoning of fuzzy logical Petri nets based on multi-task schedule

Models of a fuzzy Petri net (FPN) are defined based on generating rules of a knowledge base and the Petri nets semantics description of logical rules are presented. Two kinds of reasoning patterns are considered. First, the beliefs of initial propositions are known and their beliefs of noninitial propositions need to be computed. Second, the beliefs of initial propositions are known and the beliefs of goal propositions need to be computed. The concurrent reasoning algorithms of the two patterns based on a multi-task schedule are proposed. The application of this model and reasoning algorithm is discussed.