Real-time system support for hybrid structural simulation

Abstract

Real-time hybrid simulation (RTHS) is an important tool in the design and testing of civil and mechanical structures when engineers and scientists wish to understand the performance of an isolated component within the context of a larger structure. Performing full-scale physical experimentation with a large structure can be prohibitively expensive. Instead, a hybrid testing framework connects part of a physical structure within a closed loop (through sensors and actuators) to a numerical simulation of the rest of the structure. If we wish to understand the dynamic response of the combined structure, this testing must be done in real-time, which significantly restricts both the size of the simulation and the rate at which it can be conducted.Adding parallelism to the numerical simulation can enable both larger and higher frequency real-time simulations, potentially increasing both the accuracy and the control stability of the test. We present a proof-of-concept exploration of the execution of real-time hybrid simulations (an exemplar of a more general class of cyber-mechanical systems) with parallel computations. We execute large numerical simulations within tight timing constraints and provide a reasonable assurance of timeliness and usability. We detail the operation of our system, its design features, and show how parallel execution could enable qualitatively better experimentation within the discipline of structural engineering.

Elastic Scheduling of Parallel Real-Time Tasks with Discrete Utilizations

“…Realy-time hybrid simulation (RTHS) [9,10] combines the strengths of purely physical and purely numerical approaches. A portion of a structure is physically built to be studied, while the remainder is simulated numerically.…”

“…The Cybermech platform was developed by Ferry et al [9] to run parallel RTHS experiments. Although Cybermech supports multi-time-stepping, each subsystem only runs at a ixed periodic rate [2], and thus is only applicable to systems whose control model is linear.…”

“…We use the real-world application domain of real-time hybrid simulation (RTHS), used by earthquake engineers to understand structural behavior with high idelity at realistic timescales [9,10,19], as a motivating example for discrete elastic scheduling. In RTHS a well-understood portion of a structure is simulated while a portion to be tested or validated is physically built.…”

A Cyber-Physical Testbed for IoT Microgrid Design and Validation

“…The real-time platform may be configured for different physical parameter specifications, and, therefore, it may reduce development costs and quicken system prototyping. HIL examples are seen in vehicular technology [12,13], civil engineering [14], and power systems [15,16].…”

Analysis of Global Fixed-Priority Scheduling for Generalized Sporadic DAG Tasks

“…With the prevalence of multiprocessor platforms and parallel programming languages and runtime systems such as OpenMP [23], Cilk Plus [13,17], and Intel's reading Building Blocks [18], the demand for computer programs to be able to exploit the parallelism o ered by modern hardware is inevitable. In recent years, the real-time systems research community has worked to address this trend for real-time applications that require parallel execution to satisfy their deadlines, such as real-time hybrid simulation of structures [11], and autonomous vehicles [19].…”