Multi-threaded distributed system simulations using the transmission line element method

Abstract

By introducing physically motivated time delays, simulation models can be partitioned into decoupled independent sub-models. This enables parallel simulations on multi-core processors. An automatic algorithm is used for partitioning and running distributed system simulations. Methods for sorting and distributing components for good load balancing have been developed. Mathematical correctness during simulation is maintained by a busy-waiting thread synchronization algorithm. Independence between sub-models is achieved by using the transmission line element method. In contrast to the more commonly used centralized solvers, this method uses distributed solvers with physically motivated time delays, making simulations inherently parallel. Results show that simulation speed increases almost proportionally to the number of processor cores in the case of large models. However, overhead time costs mean that models need to be over a certain size to benefit from parallelization.

Control of Hybrid Hydromechanical Transmissions

“…Communication with the PXI computer for software model/controller updates and during HWIL simulation in real time is carried out on a LabVIEW-based Graphical User Interface (GUI) called Viking [94], see figure 3.7. See [95] for details on the implementation of the real-time Hopsan simulation and paper [II] for further details on the data acquisition system hardware.…”

Towards a Complete Co-Simulation Model Integration Including HMI Aspects

“…This ensures numerical stability, and is especially suitable for real-time simulations. TLM can also greatly reduce simulation time, as was shown by Braun et al [6] and Sjölund et al [7]. With such strategies, making advantage of the model method specific advantages and still at the same time allowing the user to use the most suitable modelling method for the problem at hand, significant improvements to the design process, time and user-friendliness can be achieved without the need to develop new modelling tools.…”

An Open-Source Framework for Efficient Co-simulation of Fluid Power Systems

“…Hence, numerical robustness will not be affected, which makes the method suitable for co-simulation [12] [7]. Besides, TLM can also be used for parallel simulation [13] [14] [15] and detailed modeling of wave propagation [16] [17] The use of TLM implies limiting the maximum step size of the simulation. For this reason, it is best suited for models where the step size is generally smaller than the physical time delays.…”