Hardware-in-the-loop Simulation Platform Research Articles

Nonlinear Control of a Hydraulic Exoskeleton 1-DOF Joint Based on a Hardware-In-The-Loop Simulation

Aiming at the difficulty of debugging the exoskeleton control system driven by a hydraulic cylinder, a research method of a nonlinear control strategy for the hydraulic exoskeleton system with 1 degree of freedom (DOF) joint is proposed. Based on a hardware-in-the-loop (HIL) simulation, this method establishes the dynamic model of the 1-DOF joint system of the hydraulic driven exoskeleton, constructs the HIL simulation test platform based on the Linux real-time kernel patch, and studies the nonlinear control strategy of the 1-DOF joint system on this platform system. The control effects of the PID control algorithm and the backstepping method on nonlinear control are compared, and the controller parameters are tested on the HIL simulation platform. From the experimental results of the HIL simulation, the research method has the advantages of low cost, high efficiency of system development, safety, and reliability. It has important reference value for the development and debugging of a hydraulic exoskeleton control system.

Research on HIL-based HVRT and LVRT automated test system for photovoltaic inverters

As an important capability of the photovoltaic grid-connected inverter, high voltage ride-through (HVRT) and low voltage ride-through (LVRT) capability are related to the stability of the whole power grid system. Therefore, according to the requirements of HVRT and LVRT standards, an automatic test and analysis system of the photovoltaic inverter is designed based on a hardware-in-the-loop (HIL) simulation platform, which saves time and human resources. Firstly, this paper analyzes the specific requirements for HVRT and LVRT capabilities in Q/GDW 1617-2015. Secondly, a HIL simulation platform is built. Thirdly, an automatic test and analysis system is developed based on Python and m language using RT-LAB and Matlab software, which can realize the automation of HVRT and LVRT test, data collection and storage, data processing and standard index calculation, and test results report generation of the photovoltaic inverter under different steady-state conditions. Finally, the correctness of the system is verified on the HIL simulation platform.

Development of an Encoding Method on a Co-Simulation Platform for Mitigating the Impact of Unreliable Communication

This article presents a hardware-in-the-loop (HIL) based modeling approach for simulating impacts of unreliable communication on the performance of centralized volt-var control and for developing an encoding method to mitigate the impacts. First, an asynchronous real-time HIL simulation platform is introduced to enable multi-rate co-simulation of a distribution system with many inverter-based distributed energy resources (DERs). The distribution system is modeled by milliseconds phasor-based models and the DERs are modeled by micro-seconds power electronic models. Communication connections between a centralized volt-var controller (modeled externally to the HIL testbed) and smart inverters are built by implementing Modbus links and the Long Term Evolution network. On this co-simulation platform, an enhanced, augmented Lagrangian multiplier based encoded data recovery (EALM-EDR) algorithm for mitigating the impact of unreliable communication is developed and validated. Simulation results demonstrate the efficacy of using the HIL-based co-simulation platform as a power grid digital twin for developing algorithms that coordinate a large number of heterogeneous control systems through wired and wireless communication links.

Lane-change path planning and control method for self-driving articulated trucks

Purpose This study aims to develop an automatic lane-change mechanism on highways for self-driving articulated trucks to improve traffic safety. Design/methodology/approach The authors proposed a novel safety lane-change path planning and tracking control method for articulated vehicles. A double-Gaussian distribution was introduced to deduce the lane-change trajectories of tractor and trailer coupling characteristics of intelligent vehicles and roads. With different steering and braking maneuvers, minimum safe distances were modeled and calculated. Considering safety and ergonomics, the authors invested multilevel self-driving modes that serve as the basis of decision-making for vehicle lane-change. Furthermore, a combined controller was designed by feedback linearization and single-point preview optimization to ensure the path tracking and robust stability. Specialized hardware in the loop simulation platform was built to verify the effectiveness of the designed method. Findings The numerical simulation results demonstrated the path-planning model feasibility and controller-combined decision mechanism effectiveness to self-driving trucks. The proposed trajectory model could provide safety lane-change path planning, and the designed controller could ensure good tracking and robust stability for the closed-loop nonlinear system. Originality/value This is a fundamental research of intelligent local path planning and automatic control for articulated vehicles. There are two main contributions: the first is a more quantifiable trajectory model for self-driving articulated vehicles, which provides the opportunity to adapt vehicle and scene changes. The second involves designing a feedback linearization controller, combined with a multi-objective decision-making mode, to improve the comprehensive performance of intelligent vehicles. This study provides a valuable reference to develop advanced driving assistant system and intelligent control systems for self-driving articulated vehicles.

An Approach to Improve System Performance in the Vehicle-Grid System Using Sliding Mode Control Under Multiple Operation Conditions

To improve the performance of vehicle-grid system under multiple operation conditions and suppress the low-frequency oscillation (LFO) in electrified railways, this paper proposed a control strategy of electric multiple units (EMUs) traction line-side converter (LSC) based on sliding mode control (SMC). First, the accurate model of EMUs is established and then the mathematical model of it in the d-q frame is derived. Then, the application of sliding mode variable structure control strategy in the LSC of EMUs is presented in detail, which includes the design of outer loop voltage sliding mode surface and inner loop current control law. Moreover, the control performance for EMUs based on SMC and traditional linear proportional integral (PI) control is compared under multiple operation conditions in the case of one traction drive unit of EMUs and multi-EMUs, respectively. Finally, experiments are implemented on the hardware in the loop simulation platform based on software StarSim. The experiments results show that, compared with PI control, SMC owns better control performance, such as the lower total harmonic distortion of traction line-side current under multiple conditions, lower voltage fluctuation when braking occurs, better anti-interference ability with the change of system parameters, and can effectively suppress the LFO occurs under operation mode.

Low-Cost Hardware-in-the-Loop Platform for Embedded Control Strategies Simulation

The increasing need for testing and prototyping designs under more realistic conditions is responsible for the advancement of new types of simulation. In this scenario, one type of simulation which has gained high notoriety and applicability is the one known as Hardware-in-the-Loop (HIL). This technique allows real and virtual components of a system to be tested together, making it possible to perform tests under realistic (and even extreme) conditions without harming the real system or a prototype built only for testing. The objective of this work was to develop a low-cost HIL simulation platform to be used for many different applications, unlike most commercial ones, that are developed for one exclusive field of application, such as automotive, aerospace, power electronics, among others. Thus, the main contribution of this work is the project of a HIL platform capable of simulating different types of systems, making it possible to validate embedded control strategies designed for them. Two different applications are tested in order to validate the HIL platform: an active suspension and a satellite attitude control air bearing table, both controlled using a discrete Linear Quadratic Regulator (LQR) designed for each of them.

Real Time Control of Hardware In-the-Loop Simulation Based on CAN Bus and RTX

In Hardware In-the-Loop Simulation(HILS) of missile, real time is the main consideration. Due to the poor real time performance of the Windows system, a real time solution scheme for HILS of missile based on the RTX system is proposed, and the design of the RTX hardware driver and the reflective memory technology are introduced. Aiming at the problem of precise timing and data synchronization in real time system, the timer of RTX is studied and a hardware solution for data synchronization is proposed. For the CAN bus to long distance transmission in high baud rate conditions, the CAN relay station is designed. The HILS platform has been built, and the result of simulation is correct without missing frames and wrong frames, meeting the requirements of stability and reliability.

Composite braking AMT shift strategy for extended-range heavy commercial electric vehicle based on LHMM/ANFIS braking intention identification

In order to improve the safety and braking energy recovery rate of the composite braking system for extended-range heavy commercial electric vehicle, AMT shift control strategy is studied based on Layering Hidden Markov Model/Adaptive Neuro-fuzzy Inference System (LHMM/ANFIS) braking intention identification model. Firstly, according to the requirement of the AMT shift strategy in braking process, the braking intentions were classified into normal braking condition and emergency braking condition. Then combined with the composite braking force distribution, the motor braking power generation characteristics and the critical condition of dangerous working state, the AMT shift strategy was analyzed and established under two braking conditions. Finally, to verify the control effect, the verification test was carried out with the initial braking speed of 60 km h−1 under the normal braking condition and the emergency braking condition separately on the hardware in the loop simulation platform based on A&D 5435 and the testing vehicle. Meanwhile, simulation study was completed in Matlab/Simulink under NEDC_90 cycle condition. The experiment and simulation results show that the developed AMT shift control strategy can accurately identify the braking intention, and the transmission shifts correctly according to corresponding conditions, which can also make the motor operating points closer to the high efficiency area. Therefore, the AMT shift control strategy proposed in this paper can effectively improve the braking energy recovery rate, and ensure the braking safety and stability.

Attitude algorithm and initial alignment method for SINS applied in short-range aircraft

This paper presents an attitude solution algorithm based on the Micro-Electro-Mechanical System and quaternion method. We completed the numerical calculation and engineering practice by adopting fourth-order Runge–Kutta algorithm in the digital signal processor. The state space mathematical model of initial alignment in static base was established, and the initial alignment method based on Kalman filter was proposed. Based on the hardware in the loop simulation platform, the short-range flight simulation test and the actual flight test were carried out. The results show that the error of pitch, yaw and roll angle is fast convergent, and the fitting rate between flight simulation and flight test is more than 85%.

Design and implementation of hardware‐in‐the‐loop simulation system for testing control and operation of DC microgrid with multiple distributed generation units

Direct current (DC) microgrid is characterised by attractive features such as high efficiency, reduced cost and needless for synchronisation. The control and operation of the DC mirogrid become significantly important with the high penetration of distributed energy resources. Therefore, development of an advanced platform for testing control and operation of the DC microgrid has attracted more and more attention nowadays. This study proposes a hardware-in-the-loop (HIL) simulation system as a new method to develop and test control algorithms and operation strategies for the DC microgrid. The proposed HIL simulation system is composed of a RT-LAB for real-time simulation, an actual controller under test, a cRIO for coordination control and the DC microgrid management system for optimal operation. Both the actual controller of key research objects and coordination control with different time scales can be tested in the proposed HIL simulation system. Hence, the platform is designed for flexibility and universality. Moreover, configuration and communication of the HIL simulation system are illustrated in this study. Finally, simulation tests are carried out to show the validation of the proposed HIL simulation platform.

Design of Real-Time Hardware-in-the-Loop TV Guidance System Simulation Platform

This paper presents a novel design of a real-time hardware-in-the-loop (HIL) missile TV guidance system simulation platform, which consists of a development computer, a target computer, a turntable, a control cabin, and a joystick. The guidance system simulation model is created on the development computer by Simulink® and then downloaded to the target computer. Afterwards, Simulink Real-Time™ runs the model in real-time. Meanwhile, the target computer uploads the real-time simulation data back to the development computer. The hardware in the simulation loop is TV camera, encoders, control cabin, servomotors, and target simulator. In terms of hardware and software, the system has been simplified compared with the existing works. The volume of the turntable integrating the target simulator and the seeker simulator is about 0.036 cubic meters compared to the original 8 cubic meters, so it has a compact structure. The platform can perform the closed-loop control, so the simulation has high precision. Taking the TV guidance simulation as an example, in the case of target maneuvering, the final miss distance of the TV guidance missile is 0.11812 m, while the miss distance of the original system is 13 m. The trajectories obtained from the HIL and mathematical simulations substantially coincide. So the simulation results show that the proposed HIL simulation platform is effective.

Hardware-in-the-loop simulation of the EAST PF converter for PF control system upgrade

The EAST poloidal field (PF) control system was upgraded in 2015 and the new system has been in use for the 2015 EAST campaign. This paper presents the implementation of a hardware-in-the-loop (HIL) simulation platform of the EAST PF converter system based on the RT-LAB simulation environment, which was used to improve and evaluate the performance of the real controller. The EAST PF power supply system and its operational modes are presented in this paper. The experiments on HIL simulation platform show that the control algorithms and the over current protection of the controller meet the design requirements well. In addition, the effectiveness of the designed control system has been verified by actual application during the EAST campaign at 2015 for six months.

Implementation of Electric Vehicle Hardware-in-the-Loop Test Platform

This paper presents a finite element model-based real-time simulation system for the permanent magnet synchronous motor (PMSM) driving system, which, in combination with the vehicle kinetic model, forms a complete electric vehicle (EV) hardware-in -theloop (HIL) simulation and test platform. The software JMAG is used to establish the PMSM finite element model, and the platform of field-programmable gate array (FPGA) is adopted to construct the PMSM real-time simulation model. The finite element model is also retrieved to coordinate with the vehicle kinetic model in order to facilitate the testing and development of the controller of the EV, the matching of the driving system, the kinetics control algorithms, etc. Through comparing the real-time simulation of the motor driving system with the experimental results of the test bench, as well as analyzing the HIL simulation results of the entire vehicle model, this paper verifies the accuracy and effectiveness of this HIL simulation and test platform.

Research on the Multi-Energy Management Strategy of the Electric Drive System of a Tracked Bulldozer

The multi-energy management strategy of electric drive system of tracked bulldozer was researched. Firstly, based on power requirement of typical working condition of a tracked bulldozer, the power distribution strategy for three energy sources in the front power chain was proposed by using wavelet theory and fuzzy control theory. Secondly, the electric drive system simulation platform was built in MATLAB/Simulink. At last, a driver-controller based HILS (hardware-in-the-loop simulation) platform was built and the multi-energy management strategy was verified. The HILS result shows that front power chain’s power output can meet the back power chain’s requirement, the engine-generator set works near the best fuel consumption curve, and the battery pack’s charge-discharge frequency and current are low. Thus the designed multi-energy management strategy can be used in real-time control of electric drive bulldozer.

Design and Optimization of the Power Management Strategy of an Electric Drive Tracked Vehicle

This article studies the power management control strategy of electric drive system and, in particular, improves the fuel economy for electric drive tracked vehicles. Combined with theoretical analysis and experimental data, real-time control oriented models of electric drive system are established. Taking into account the workloads of engine and the SOC (state of charge) of battery, a fuzzy logic based power management control strategy is proposed. In order to achieve a further improvement in fuel economic, a DEHPSO algorithm (differential evolution based hybrid particle swarm optimization) is adopted to optimize the membership functions of fuzzy controller. Finally, to verify the validity of control strategy, a HILS (hardware-in-the-loop simulation) platform is built based on dSPACE and related experiments are carried out. The results indicate that the proposed strategy obtained good effects on power management, which achieves high working efficiency and power output capacity. Optimized by DEHPSO algorithm, fuel consumption of the system is decreased by 4.88% and the fuel economy is obviously improved, which will offer an effective way to improve integrated performance of electric drive tracked vehicles.

Hardware-in-the-loop simulation platform for supervisory control of mineral grinding process

Supervisory control technology is widely used to improve product quality in mineral grinding process (MGP). To ensure safety, new supervisory control method needs to be fully tested before practical application. However, conducting tests in a running process is costly and may put the process equipment in danger, which necessitates extensive simulations to ensure the stability and performance of supervisory controllers. Comparing with the field based test, the numerical simulation is more economic and safer. However, numerical simulations cannot capture all aspects of controlled object, such as sensors, actuators, process, control systems themselves and signal transmissions, which are important to evaluate the control performances. To solve this problem, this paper presents a novel hardware-in-the-loop simulation (HILS) platform for the supervisory control of MGP. By integrating a supervisory control system, a basic loop control system, a virtual actuator and sensor system, and a virtual plant system in to a coherent whole, the HILS platform provides a full-scope simulation environment for the supervisory control. The supervisory control system and the basic loop control system adopt real control systems. The detailed process dynamics are modeled and visualized by the virtual plant system. Further, as an interface between the physical controllers and virtual plant, the virtual actuator and sensor system is used to realize the signal conversion and to simulate the dynamics and faults of the actuators and sensors using data acquisition (DAQ) hardware and configuration software. Effectiveness of platform is demonstrated with a case study, where an intelligent supervisory control method for a typical one stage MGP is tested.

Hardware in the loop simulation test platform of fuel cell backup system

Based on an analysis of voltage mechanistic model, a real-time simulation model of the proton exchange membrane (PEM) fuel cell backup system is developed, and verified by the measurable experiment data. The method of online parameters identification for the model is also improved. Based on the software LabVIEW/VeriStand real-time environment and the PXI Express hardware system, the PEM fuel cell system controller hardware in the loop (HIL) simulation plat-form is established. Controller simulation test results showed the accuracy of HIL simulation platform.

Nonlinear Coupling Characteristics Analysis of Integrated System of Electromagnetic Brake and Frictional Brake of Car

Since theoretical guidance is lacking in the design and control of the integrated system of electromagnetic brake and frictional brake, this paper aims to solve this problem and explores the nonlinear coupling characteristics and dynamic characteristics of the integrated system of electromagnetic brake and frictional brake. This paper uses the power bond graph method to establish nonlinear coupling mathematical model of the integrated system of electromagnetic brake and frictional brake and conducts the contrastive analysis on the dynamic characteristics based on this mathematical model. Meanwhile, the accuracy of the nonlinear coupling mathematical model proposed above is verified on the hardware in the loop simulation platform, and nonlinear coupling characteristics of the integrated system are also analyzed through experiments.

Research on Energy Management Control Strategy by dSPACE Based Half-Practicality Simulation

In order to manage the power of electric drive system effectively and improve the fuel economy and working efficiency of electric drive tracked vehicle, this paper proposed a novel energy management control strategy based on the theory of threshold logic and fuzzy logic. The mathematical models of the key components of electric drive system were built in SIMULINK. To examine and analysis the efficiency of control strategy, a driver-controller based HILS (hardware-in-the-loop simulation) platform was built and the energy management control strategy was verified. The simulation results reveal that the strategy have excellent performance in energy distribution, fuel saving and working efficiency, and the proposed control strategy is simple and easy to realize in a real controller, which provides an effective method for the design and application of energy management control strategy of electric drive tracked vehicle.

EcoHILS를 활용한 효율적인 CPS 시험에 관한 연구

Cyber-Physical Systems(CPS) that mostly provides safety-critical and mission-critical services requires high reliability, so that system testing is an essential and important process. Hardware-In-the-Loop Simulation(HILS) is one of the extensively used techniques for testing hardware systems. However, most conventional HILS has problems that it is difficult to support a distributed operating environment and to reuse a HILS platform. In this paper, we introduce EcoHILS(ETRI CPS Open Human-Interactive hardware-in-the-Loop Simulator) in order to test CPS effectively. Moreover, feasibility tests and performance tests of EcoHILS are performed to confirm its effectiveness.