Event-based Synchronization Research Articles

Signal synchronization methods when measuring tailpipe emissions with PEMS

This study describes the effects of using different signal synchronization methods on the tailpipe emission factors obtained by on-road tests using PEMS (Portable Emission Measurement Systems). The event-based, static correlation, and dynamics correlation methods were applied to data obtained using different PEMS. The first database included 36 cargo vehicles following the same driving cycle in various cities in Colombia. The second database involved 16 passenger transport vehicles monitored under real operating conditions in Mexico. When comparing results with the event-based synchronization method as the reference, significant differences in emission factors (>25 %) were observed. Those differences depend directly on the physical setup of the PEMS. The dynamic correlation method exhibited the best performance in all cases. When using this method, we recommend to synchronize the CO2 mass flow and fuel consumption variables first and then adjust the obtained synchronization to other species to account for differences in species diffusivities.

Event-triggered extended dissipative synchronization for delayed neural networks with random uncertainties

This paper aims to study a generalized robust dynamical behavior called the extended dissipative synchronization of neural networks with time-varying delay and random uncertainties. To achieve the primary objective of minimizing network resource utilization while preserving desired closed-loop performance, an event-triggered control scheme is implemented. By constructing an augmented form of Lyapunov–Krasovskii functional and utilizing generalized integral inequalities, two novel synchronization criteria have been proposed in the form of linear matrix inequalities. It is worth noting that this paper studies a generalized dissipative performance index, enabling the various event-based synchronization problems, including H∞, L2−L∞, passivity, and (Q,S,R)−γ−dissipative synchronization in a unified framework. Ultimately, the efficacy and benefits of the suggested approach are demonstrated through two numerical examples.

Synchronisation of wearable inertial measurement units based on magnetometer data.

Synchronisation of wireless inertial measurement units in human movement analysis is often achieved using event-based synchronisation techniques. However, these techniques lack precise event generation and accuracy. An inaccurate synchronisation could lead to large errors in motion estimation and reconstruction and therefore wrong analysis outputs. We propose a novel event-based synchronisation technique based on a magnetic field, which allows sub-sample accuracy. A setup featuring Shimmer3 inertial measurement units is designed to test the approach. The proposed technique shows to be able to synchronise with a maximum offset of below 2.6ms with sensors measuring at 100Hz. The investigated parameters suggest a required synchronisation time of 8 s. The results indicate a reliable event generation and detection for synchronisation of wireless inertial measurement units. Further research should investigate the temperature changes that the sensors are exposed to during human motion analysis and their influence on the internal time measurement of the sensors. In addition, the approach should be tested using inertial measurement units from different manufacturers to investigate an identified constant offset in the accuracy measurements.

Event-Based Control for Synchronization of Stochastic Linear Systems with Application to Distributed Estimation

This paper studies the synchronization of stochastic linear systems which are subject to a general class of noises, in the sense that the noises are bounded in covariance but might be correlated with the states of agents and among each other. We propose an event-based control protocol for achieving the synchronization among agents in the mean square sense and theoretically analyze the performance of it by using a stochastic Lyapunov function, where the stability of c-martingales is particularly developed to handle the challenges brought by the general model of noises and the event-triggering mechanism. The proposed event-based synchronization algorithm is then applied to solve the problem of distributed estimation in sensor network. Specifically, by losslessly decomposing the optimal Kalman filter, it is shown that the problem of distributed estimation can be resolved by using the algorithms designed for achieving the synchronization of stochastic linear systems. As such, an event-based distributed estimation algorithm is developed, where each sensor performs local filtering solely using its own measurement, together with the proposed event-based synchronization algorithm to fuse the local estimates of neighboring nodes. With the reduced communication frequency, the designed estimator is proved to be stable under the minimal requirements of network connectivity and collective system observability.

Distributed Dynamic Event-Based Control for Nonlinear Multi-Agent Systems

This brief studies the synchronization problem for a class of QUAD and interconnected nonlinear multi-agent systems (MASs). A dynamic event-based control scheme is designed, and two event-based synchronization conditions are constructed by utilizing stability theory. Moreover, the Zeno-behavior can be excluded in the MASs. An example and its simulation are given to verify the applicability of the designed dynamic event-based protocol for MASs.

Event-Based Synchronization for Multiple Neural Networks With Time Delay and Switching Disconnected Topology.

This article discusses the synchronization problem for a class of multiple delayed neural networks (MDNNs) with a directed switching topology by using an event-triggering strategy. First, a new differential inequality with delay is shown, which is a generalization of Halanay-type inequalities. Then, the sufficient conditions of event-based synchronization (quasisynchronization) for MDNN with sequentially connected topology are obtained by using this inequality and the iterative method. Meantime, we prove that Zeno behavior can be avoided under the designed event-triggering rules. As an extension, MDNN with jointly connected topology is also discussed. Finally, a numerical example is listed to illustrate the results in theory analysis.

Design and Implementation of a Communication Middleware for Electronic Devices of Unmanned Surface Vehicle

본 논문에서는 카메라 및 다양한 센서가 복합되어 고속의 데이터를 다중으로 처리하는 성능을 요구하는 전자광학장비의 안정적인 데이터 전송을 위해 Event 기반의 동기화 방식을 통한 Multi-Thread 환경의 다중 통신 미들웨어 설계 및 구현 방법을 제안하였다. 구현된 통신 미들웨어의 성능 검증을 위해 영상 데이터 및 센서 데이터를 전송하여 송신 주기 대비 수신 주기에 대한 차이를 비교하고, 다중으로 전송 및 처리할 수 있는 최대 통신 가능 수를 측정 및 분석하였다. 또한 전송되는 데이터의 무결성 검증과 Round Trip Time 측정 등의 실험을 통해 제안하는 통신 미들웨어의 성능을 검증하였다.In this paper, designing and implementing multi-communication middleware in multi-thread environmet through event-based synchronization method are proposed for stable data transmission of electronic optical equipment, which requires combining camera and various sensors to process multiple high-speed data. To verify the performance of the implemented communication middleware, image data and sensor data were sent to compare differences in reception-based and transmission-based cycles, and the maximum number of communication possibilities to transmit and process multiple was measured and analyzed. In addition, the proposed communication middleware’s performance was verified through experiments such as validating the integrity of the transmitted data and measuring the Round Trip Time.

Event-Based Synchronization of Heterogeneous Complex Networks Subject to Transmission Delays

In this paper, the problem of event-based synchronization of heterogeneous complex networks is investigated. Specifically, the influence of transmission delays on event-based synchronization is considered. The designed distributed controller for each nonidentical node in heterogeneous network includes reference generator (RG) and robust regulator. Event-based communication protocol is utilized to ensure the synchronization among the identical RGs and target leader. Meanwhile, the interevent intervals are lower bounded by a positive constant. Furthermore, the proposed high-gain output feedback and adaptive control law guarantee that all nonidentical nodes converge to their RGs. Based on these two steps, which are coincided with the separation principle, nonidentical nodes can track the target leader. In addition, theoretical results are demonstrated by a numerical example.

Event-Based Synchronization Control for Memristive Neural Networks With Time-Varying Delay.

In this paper, we investigate the global synchronization control problem for memristive neural networks (MNNs) with time-varying delay. A novel event-triggered controller is introduced with the linear diffusive term and discontinuous sign term. In order to greatly reduce the computation cost of the controller under certain event-triggering condition, two event-based control schemes are proposed with static event-triggering condition and dynamic event-triggering condition. Some sufficient conditions are derived by these control schemes to ensure the response MNN to be synchronized with the driving one. Furthermore, under certain event-triggering conditions, a positive lower bound is achieved for the interexecution time to guarantee that Zeno behavior cannot be executed. Finally, numerical simulations are provided to substantiate the effectiveness of the proposed theoretical results.

Multi-agent planning under local LTL specifications and event-based synchronization

We study the problem of plan synthesis for multi-agent systems, to achieve complex, high-level, long-term goals that are assigned to each agent individually. As the agents might not be capable of satisfying their respective goals by themselves, requests for other agents’ collaborations are a part of the task descriptions. We consider that each agent is modeled as a discrete state-transition system and its task specification takes a form of a linear temporal logic formula. A traditional automata-based approach to multi-agent plan synthesis from such specifications builds on centralized team planning and full team synchronization after each agents’ discrete step, and thus suffers from extreme computational demands. We aim at reducing the computational complexity by decomposing the plan synthesis problem into finite horizon planning problems that are solved iteratively, upon the run of the agents. We introduce an event-based synchronization that allows our approach to efficiently adapt to different time durations of different agents’ discrete steps. We discuss the correctness of the solution and find assumptions, under which the proposed iterative algorithm leads to provable eventual satisfaction of the desired specifications.

Event‐based synchronisation of linear discrete‐time dynamical networks

This study investigates the problem of event-based synchronisation of linear discrete-time dynamical networks. Leader-following and leaderless synchronisations are achieved by a distributed event-trigger strategy. It is shown that feedback control updating is unnecessary until an event is triggered. The combinational-state variables and the Riccati equation are used to construct a Liapunov function and to design the event-triggering conditions. Numerical examples are provided to illustrate the theoretical results.

Event-based synchronisation of multi-agent systems

This paper investigates the synchronization problem of multi-agent systems with event-based communication. A communication between the agents is invoked only after an event condition has been fulfilled, which can be checked in a decentralized way. Event-based synchronization reduces the communication effort in comparison to the continuous-time synchronization algorithms, while the convergence of the subsystems to a bounded region around the synchronous trajectory is guaranteed.

Performance-driven event-based synchronization for multi-FPGA simulation accelerator with event time-multiplexing bus

Simulation is the most viable solution for the functional verification of system-on-chip (SoC). The acceleration of simulation with multi-field programmable gate array (multi-FPGA) emulator is a promising method to comply with the increasing complexity and large gate capacity of SoC. Time multiplexing of interconnection wires is the inevitable solution to solve the pin limitation problem that limits the gate utilization of FPGAs and speed of multi-FPGA simulation accelerators. The most time-consuming factor of multi-FPGA simulation acceleration is the synchronization time between a software simulator and a multi-FPGA system and the inter-FPGA synchronization time. This paper proposes a performance-driven signal synchronization mechanism for a simulation accelerator with multiple FPGAs using time-multiplexed interconnection. The event-based signal synchronization optimizes the synchronization time between a software simulator and the multi-FPGA system as well as the synchronization time among FPGAs. The synchronization time among FPGAs is optimized by circuit partitioning considering the signal probability, net dependency reduction, and efficient net clustering to reduce addressing overhead. The synchronization time between the software simulator and the multi-FPGA system is also optimized by exploiting the event probability of primary nets. Experiments show that the synchronization time is reduced to 6.2-9.8% of traditional mechanisms.

A transaction-based unified architecture for simulation and emulation

The availability of millions of transistors on a single chip has allowed the creation of complex on-chip systems. The functional verification of such systems has become a challenge. Simulation run times are increasing, and emulation is now a necessity. Creating separate verification environments for simulation and emulation slows the design cycle and it requires additional human efforts. This paper describes a layered architecture suitable for both simulation and emulation. The architecture uses transactions for communication and synchronization between the driving environment (DE) and the device under test (DUT). Transactions provide synchronization only as needed and cycle and event-based synchronization common in emulators. The result is more efficient development of the DE and 100% portability when moving from simulation to emulation. We give an overview of our layered architecture and describe its implementation. Our results show that, by using emulation, the register-transfer level (RTL) implementation of an industrial design can be verified in the same amount of time it takes to run a C-based simulation. We also show two orders of magnitude speeds up over simulations of C and RTL through a programming language interface

A standard model for multimedia synchronization: PREMO synchronization objects

This paper describes an event-based synchronization mechanism, which is at the core of the inter-media synchronization in the upcoming standard for multimedia presentation, PREMO. The synchronization mechanism of PREMO is a powerful tool, based on a small number of concepts, and on cooperation among active objects, and represents a synthesis of various synchronization models described in the literature. This model can serve as a basis for the implementation of complex synchronization patterns in multimedia presentations, both purely event-based, as well as time-based.