Real-time Hardware-in-the-loop Simulation Research Articles

Brake performance evaluation of ABS with sliding mode controller on a split road with driver model

In this paper, Sliding Mode Controller (SMC) is proposed to enhance Anti-Lock Brake System (ABS) performance. To verify SMC performance, a real-time Hardware in the loop simulation has been created with a hydraulic brake line. Therefore, the hydraulic brake model and vehicle model should be properly set up to acquire exact simulation results. In addition, the experiment results are compared with that of the commercial ABS with ECU only, and verified how much the performance is improved. The control strategy is to follow the target slip ratio by means of sliding mode controller and secure the vehicle stability while the vehicle braking on various road conditions, such as dry road, wet road, icy road and even split road condition. The driver model is useless on the uniform slip ratio of a straight road. However, the split road has to adopt the driver model. The split road condition has a different slip ratio at each wheel, causing the vehicle to spin out. Test results show that ABS with sliding mode controller has better performance than existing ABS and also ensures improved vehicle stability. Furthermore, the test result on the split road shows how the vehicle will follow the desired path with the driver model and hold the target slip ratio.

Real-time multi-rate HIL simulation platform for evaluation of a jet engine fuel controller

A new Hardware-In-the-Loop (HIL) platform is developed for testing of a turbojet engine fuel control system using a multi-rate simulation platform. The HIL equipment consists of an industrial PC and a commercial I/O board for jet engine simulation as the controlled process and an Electronic Control Unit (ECU) as the fuel controller. The controlled process consisting of actuator, physical process and sensors is fully simulated in HIL simulation. However, the high resolution signals of some components in the HIL simulation cause the real-time simulation to become difficult due to the need of small time-steps. As a result, the disparity between the jet engine model sampling rate and these high resolution signals requires a multi-rate simulation. In this study, a multi step size simulation is developed using multiple processors. These processors are designed to synchronize the status of the engine model with the control system as well as to convert the raw data of the I/O boards to actual input and output signals in real-time. These features make the HIL equipment more effective and flexible. The HIL environment is proved to be an efficient tool to develop various control functions and to validate the software and hardware of the engine fuel control system.

Real-Time Simulation of a Wind Turbine Generator Coupled With a Battery Supercapacitor Energy Storage System

Wind power generation studies of slow phenomena using a detailed model can be difficult to perform with a conventional offline simulation program. Due to the computational power and high-speed input and output, a real-time simulator is capable of conducting repetitive simulations of wind profiles in a short time with detailed models of critical components and allows testing of prototype controllers through hardware-in-the-loop (HIL). This paper discusses methods to overcome the challenges of real-time simulation of wind systems, characterized by their complexity and high-frequency switching. A hybrid flow-battery supercapacitor energy storage system (ESS), coupled in a wind turbine generator to smooth wind power, is studied by real-time HIL simulation. The prototype controller is embedded in one real-time simulator, while the rest of the system is implemented in another independent simulator. The simulation results of the detailed wind system model show that the hybrid ESS has a lower battery cost, higher battery longevity, and improved overall efficiency over its reference ESS.

Equivalent Hardware Representation of PM Synchronous Motors From the Physics-Based Phase Variable Model Obtained Through FE Computation

This paper presents an approach utilizing a machine model to achieve an equivalent hardware representation of machines as a computational prototyping tool. The purpose of our study is to find a way to perform hardware experiments of machine control without the actual machine. The proposed approach provides a way to test the control before the machine is fabricated, or in the cases where the controller needs to be experimentally tested before being implemented onto the actual machine. The equivalent hardware of a machine is built using a current controllable load, a controller, and a machine model in a hardware-in-the-loop (HIL) real time simulation environment. The equivalent hardware representation of the machine is achieved by controlling the currents of the controllable load to be the same as the currents of the actual machine under the same operating conditions. The machine model is used to provide the reference signal for the control. In this paper, the introduction of the proposed approach is presented focusing on three issues: the machine model, the procedure to enable the machine model to be compatible with the HIL real time simulation, and performance examination. Finally, the validity of the proposed approach is demonstrated with the voltage and current waveforms and the torque and speed profiles measured at the developed equivalent hardware of the machine. A 2-hp surface mounted permanent magnet (PM) synchronous motor is used as an example machine to present and verify our work.

Real-time simulation of a COGAG naval ship propulsion system

Design and optimization of the propulsion system is a crucial task of the ship design process. The behaviour of the propulsion system, in transient conditions as well as in steady state, is greatly affected by the capability of the control system to manage the available power and to achieve the desired performance in the shortest time. The selection of a proper control scheme is a trade-off between different and conflicting needs. Two of the opposites are: increasing the ship operability by adding more functions and more controls; and reducing the control system development and installation time and cost. In this paper, the rapid prototyping and testing procedure for the development of the propulsion controller of the new Italian aircraft carrier Cavour is presented, using real-time hardware-in-the-loop (RT-HIL) simulation. The procedure is based on a wide use of simulation technology. First, a complete dynamical model of the ship propulsion plant was developed. Then, batch simulation was used to develop the best possible control scheme. Finally, RT-HIL simulation was used to debug the real controller software and to tune the controller parameters before sea trials. The application of the procedure led to a significant reduction in the development phase of the controller design. Furthermore, the adoption of the RT-HIL technology greatly reduced the time spent to tune the control system during the ship delivery phase.