Hardware-in-the-loop Test Research Articles

Modelling, hardware-in-the-loop tests and numerical simulation of magneto-rheological semi-active primary suspensions in a railway vehicle

ABSTRACT Semi-active primary suspensions are an effective means of improving ride quality in high-speed railway vehicles in relation to the mitigation of car-body bending vibration. In this paper, prototype magnetorheological (MR) dampers are tested and the results are used to define a mathematical model of the dampers. Then, three control schemes for semi-active primary suspensions are proposed: Skyhook, LQG and Mix-1-Sensor, and their performance is assessed by means of Hardware-In-the-Loop (HIL) tests considering a simple quarter-vehicle model which is run on a real-time board and set in interaction with one physical MR damper. The results show that all three considered control strategies lead to a reduction of car-body vibration by around 30% and a very good agreement is found between HIL tests and numerical simulations in which the physical damper is replaced by the mathematical damper model. The damper model is finally interfaced with a flexible multi-body model of the complete vehicle to provide further assessment of semi-active control. The results of the latter simulations show that the semi-active suspension could provide an improvement of the N mvz ride quality index in the order of 40–45% with respect to the passive vehicle for all three control schemes.

GRU-Based Denoising Autoencoder for Detection and Clustering of Unknown Single and Concurrent Faults during System Integration Testing of Automotive Software Systems.

Recently, remarkable successes have been achieved in the quality assurance of automotive software systems (ASSs) through the utilization of real-time hardware-in-the-loop (HIL) simulation. Based on the HIL platform, safe, flexible and reliable realistic simulation during the system development process can be enabled. However, notwithstanding the test automation capability, large amounts of recordings data are generated as a result of HIL test executions. Expert knowledge-based approaches to analyze the generated recordings, with the aim of detecting and identifying the faults, are costly in terms of time, effort and difficulty. Therefore, in this study, a novel deep learning-based methodology is proposed so that the faults of automotive sensor signals can be efficiently and automatically detected and identified without human intervention. Concretely, a hybrid GRU-based denoising autoencoder (GRU-based DAE) model with the k-means algorithm is developed for the fault-detection and clustering problem in sequential data. By doing so, based on the real-time historical data, not only individual faults but also unknown simultaneous faults under noisy conditions can be accurately detected and clustered. The applicability and advantages of the proposed method for the HIL testing process are demonstrated by two automotive case studies. To be specific, a high-fidelity gasoline engine and vehicle dynamic system along with an entire vehicle model are considered to verify the performance of the proposed model. The superiority of the proposed architecture compared to other autoencoder variants is presented in the results in terms of reconstruction error under several noise levels. The validation results indicate that the proposed model can perform high detection and clustering accuracy of unknown faults compared to stand-alone techniques.

Synthesis and Implementation of Distributed Supervisory Controllers With Communication Delays

In literature, extensive research has been done with respect to synthesis of supervisory controllers. Such synthesized supervisors can be distributed for implementation on multiple physical controllers. This paper discusses a method for distributing a synthesized supervisory controller. In this method, dependency structure matrices are used to distribute a system, the supervisor is then distributed accordingly, using existing localization theory. The existence of communication delays between supervisory controllers is unavoidable in a distributed application. The influence of these delays on the behavior of a supervisor is therefore studied using delay robustness theory. This paper introduces the use of mutex algorithms to make the distributed supervisor delay-robust. A case study is used to demonstrate the method and hardware in the loop testing is used to validate the resulting distributed supervisor.

Co-optimization energy management strategy for a novel dual-motor drive system of electric tractor considering efficiency and stability

The challenge in developing an electric tractor control strategy lies in operating efficiently and smoothly in most conditions. This paper put forward a co-optimization energy management strategy (EMS) for dual-motor electric tractors to achieve working efficiency and smoothness simultaneously in typical conditions including ploughing, rotary tillage and transportation. Firstly, the mathematical models for components of the drive system are established, such as the power transfer model and gear shifting model. Secondly, the novel EMS combining demand torque calculation method (DTCM) and driving torque distribution strategy (DTDS) is proposed, which is based on nonlinear PID control and modified snake optimizer (SO) algorithm respectively. Then, the hardware in the loop (HIL) platform is manufactured, and load data for the HIL test collecting by a tractor operating in the field. Finally, the performances of the electric tractor with the novel EMS in three typical conditions are validated. It shows that EMS can identify the demand torque accurately. Compared to the rule-based algorithm with reasonable parameters, the novel EMS improves efficiency and stability significantly, especially in ploughing increasing efficiency by 14.44% and decreasing jerk fluctuates by 73.33%. The research results can provide theoretical references for developing the EMS of the electric tractor.

Vehicle Power System Modeling and Integration in Hardware-in-the-Loop (HIL) Simulations

The last decade has seen a rapid increase in the development and launch of a large number of hybrid and electric vehicles on the world market, a trend that is expected to accelerate in the medium to long term. However, not all markets in the world follow this trend at the same speed, conventional vehicles based on conventional energy systems, as start–stop systems, are prevalent in emerging markets. In Brazil, a unique biofuel energy program using sugar cane ethanol as an alternative fuel for ICE (internal combustion engines) has been successful for over forty years, and it can be used together with hybrid technologies. The introduction of micro-hybrid technologies and strategies in conventional vehicles has a significant impact on power system management, and developing and analyzing new systems and strategies can be time-consuming and expensive. Hence, the development of new HIL (hardware-in-the-loop) test systems or new methods for existing HIL systems is critical. In this paper, a modeling technique is suggested to incorporate a vehicle’s energy system into current HIL systems for studying micro-hybrid technologies and evaluating new proposals. By analyzing the impact of various strategies on fuel efficiency and the energy balance of the electric system, this modeling technique can assist in enhancing vehicle system efficiency, reducing fuel consumption, and lowering emissions.

X-in-the-Loop-Based High Accuracy Test Facility for Industrial Development of Electric Vehicles

The present paper offers a complete, flexible and adaptable solution for electric vehicles industrial developers to test their designs from all the perspectives required by a V-mode development approach. Construction of high accuracy mechanical and electrical real-time digital-twin models fuzzing dedicated software was proven to be the proper solution to reach results confirmed by actual measurements. Methods for transitioning from real-time simulations to emulations or hardware in the loop testing are presented in detail. The digital-twin solution performing real-time simulations are considered to be the virtual test facility presented in the paper. For actual validation, preliminary the battery is studied via hardware emulation and hardware testing. The same approach is then applied to the vehicle motor together with its electronics and control. The added value of the paper is brought by several aspects such as the real-time co-simulation, performed using National Instruments VeriStand software aggregator, the methods of virtual, emulation and hardware testing of the same assemblies, all being confirmed by comparative analysis. The increased precision obtained, proved by actual measurements, estimates the value and usefulness of this study for those working in electric vehicles development. The content of the paper is an extended genuine study giving hands-on solutions for different types of approaches when it comes to developing and testing mechanical or electrical assemblies. The paper gives a theoretical background pushed to the application side confirmed by actual laboratory testing.

Experimental study on transient heat transfer performance of high temperature heat pipe under temperature feedback heating mode for micro nuclear reactor applications

The use of heat pipe-cooled micro nuclear-powered reactors (HPNRs) is crucial for shaping a low-carbon energy structure in the future. However, there is still a lack of experimental investigations on the transient heat transfer performance of high-temperature heat pipes (HTHPs) under the application of HPNRs. To address this issue, a hardware-in-the-loop (HIL) test platform has been developed to dynamically adjust the heating power of the heat pipe in real-time considering the temperature feedback (TF) effect. A horizontal test rig composed of a hex block, a sodium heat pipe, and six electric heaters has been built in the laboratory, and its thermal effectiveness has been evaluated at 60%. Subsequently, a transient HIL test under the TF heating mode has been conducted. The results show that the frozen start-up of the HTHP can be divided into five stages based on the power exponential growth rate and the state of the sodium vapor. During the transient start-up process, the worst axial heat transfer of the HP occurs when the front of the continuum vapor arrives at the adiabatic section, where the maximum thermal resistance is 500 K/W. Heat pipes with a high filling ratio can avoid integral overheating of the evaporator when occurring viscosity limit at the start-up period. Different time scales of neutron growth and thermal inertia cause alternating oscillation of power and temperature. This work provides valuable insights into the transient heat transfer behavior of the HTHP under the running process of the HPNR system.

A new application of the hardware in the loop test of the min–max controller for turbofan engine fuel control

AbstractThis article performs a novel hardware test application on the min–max algorithm to control a two‐axis turbofan engine's fuel with a high bypass ratio. In this technique the microcontroller uses a nonlinear model based on the min–max algorithm to control the turbofan's fuel consumption. The min–max control method precisely provides the desired thrust while meeting the engine's physical and operational limitations. By setting the engine's limits appropriately, a surge is prevented from happening due to overheating of the turbine. As a proof of concept, the proposed fuel control algorithm is verified using an Intel Addison's Arduino microcontroller connected to a computer. The implemented hardware is examined by incorporating it into a typical control loop test and monitored via a computer. The achieved results indicate fast time response and algorithm flexibility in simulation modes. The test results confirm the precision and proper implementation of the proposed min–max control algorithm. In addition, the suggested min–max control algorithm can be applied to realize restrictions such as the rotational speed and the outlet pressure of the high‐pressure compressor under the required conditions.

Validation of automotive centrals using hardware in the loop -BCM and Lights

The race for electrification and the need for innovation to attract customers has driven the automotive industry to do something different in vehicles, emerging emission control challenges and efficient technological availability are the pillars of innovation. With the need to upgrade industrial manufacturing systems, directly impacting vehicle production, established the search for new prototyping methodologies and use of virtual tools for testing, validation of components and vehicle systems are developed. The demand for electronic components controls units (ECU) is growing, due to the availability of intelligence and security in today's vehicles, directly impacting their development and the performance and functionality tests. To meet this new reality, in addition to the automotive test prototypes used during development, the automotive industry has been using different virtual environments to produce, verify, and validate its vehicles. Therefore, this paper applied integration and validation using the HIL test platform, focusing on the ECU Body Control Unit (BCM), analyzing its functionalities and possible failures of the internal and external light loads. After, a brief commentary will be made exposing other test medium platforms given as the Plywood Buck (PWB), checking the reliability, flexibility, installation time, and costs of the three test platforms Software in the loop (SIL), Model in the loop (MIL) , Hardware in the loop (HIL), in order to verify their advantages, challenges, and problems in the use and information to optimize the use of each platform and test medium.

Hardware-in-the-loop simulations of a railway pantograph with a finite element periodic catenary model

The pantograph-catenary dynamic interaction problem is addressed by Hardware-in-the-Loop (HIL) tests to simulate the dynamic interaction between a numerical model (the catenary) and a physical device (the pantograph). The real-time simulation requires a computationally efficient numerical model and an on time and accurate transference of the response to the pantograph, for which a Periodic Finite Element Model (PFEM) of the catenary is considered. Firstly because of the acceptable computation time required to solve it, makes it suitable for real-time simulations and, secondly, its ability to allow for the delay caused by the transfer of the numerical model response. The catenary PFEM we used considers the non-linear behaviour of the dropper slackening, leading to highly accurate HIL test results, which were validated up to a frequency of 25 Hz.

Longitudinal and lateral coupling vehicle stability controller designed based on piecewise T-S fuzzy model

Due to tire force coupling and load transfer coupling during the stability control process, the vehicle longitudinal and lateral dynamics shows particularly obvious nonlinear coupling characteristics, which will deteriorate the performance of the stability controller. This paper proposes a Vehicle Stability Controller considering the vehicle longitudinal and lateral coupling characteristics. First, a piecewise guidance method, including the Adaptive Linear Regression Algorithm and Dimensionless Performance Evaluation Weighting Function, is developed to ensure the Takagi-Sugeno fuzzy model piecewise approaches the nonlinear characteristics of the original system and obtains the multiple linear fuzzy subsystems. Then, an H∞ robust controller with dynamic output feedback is used in each fuzzy subsystem based on the identification result of the driving intention, and the Linear Matrix Inequality is applied to obtain the controller gains. Subsequently, the Parallel Distributed Compensation architecture is adopted to integrate the outputs of all fuzzy subsystems, and vehicle stability controller is realized by using a rule-based control distribution strategy. The proposed controller is evaluated by simulations and hardware in the loop tests, and the results demonstrate satisfactory longitudinal following ability and lateral stability.

HIL testing of wheel slide protection systems: criteria for continuous updating and validation

Assessment of railway wheel slide protection (WSP) systems involves the execution of complex experimental activities that are quite expensive and time-consuming, since they involve the physical reproduction of degraded adhesion conditions on a real railway line. WSP is devoted to regulating applied braking forces to avoid excessive wheel sliding in case of degraded adhesion conditions between wheel and rail. WSP must be also compliant to safety specifications related to assured braking performances and consumed air. Hardware in the loop (HIL) testing offers an affordable and sustainable way to accelerate these activities optimizing cost, duration and safety of experimental activities performed online. HIL test rigs are subjected to continuous updates, customization and natural ageing of their components. This work investigates the criteria that can be adopted to assure a continuous monitoring and validation of a real WSP test rig, the Italian test rig of Firenze Osmannoro.

Visual based GNC system from prototype to flight software

Juventas is a 6U CubeSat which is part of HERA planetary defense mission and takes advantage of an innovative visual based guidance, navigation and control (GNC) system to perform autonomous navigation in the proximity of the Didymain system. The GNC system is designed to ensure safe navigation in the harsh and unpredictable environment of deep space and finally to take more risks by landing on the surface of Dimorphos. To achieve a qualitative software (SW) product, a dedicated procedure of SW lifecycle is developed by starting with GNC and image processing design, which concludes with the final embedded system that will perform the visual navigation task. A Design, Development, Verification and Validation (DDVV) approach is developed to achieve the flight software: model in the loop (MIL), auto-coding, software in the loop (SIL), processor in the loop (PIL) and finally hardware in the loop (HIL). The DDVV is developed by having as guideline the ECSS standards for SW. The flight software reaches maturity by performing dynamic/static code analysis and code coverage. To ensure an optimal process, a waterfall life-cycle is considered, where dedicated MIL, SIL, PIL and HIL test benches are developed to fully support the activity and to reduce to minimum the development costs.[7]

Low-Cost Hardware in the Loop for Intelligent Neural Predictive Control of Hybrid Electric Vehicle

The design and investigation of an intelligent controller for hardware-in-the-loop (HIL) implementation of hybrid electric vehicles (HEVs) are proposed in this article. The proposed intelligent controller is adopted based on the enhancement of a model predictive controller (MPC) by an artificial neural network (ANN) approach. The MPC-based ANN (NNMPC) is proposed to control the speed of HEVs for a simulation system model and experimental HIL test systems. The HIL is established to assess the performance of the NNMPC to control the velocity of HEVs in an experimental environment. The real-time environment of HIL is implemented through a low-cost approach such as the integration of an Arduino Mega 2560 and a host Lenovo PC with a Core i7 @ 3.4 GHz processor. The NNMPC is compared with a proportional–integral (PI) controller, a classical MPC, and two different settings of the ANN methodology to verify the efficiency of the proposed intelligent NNMPC. The obtained results show a distinct behavior of the proposed NNMPC to control the speed of HEVs with good performance based on the distinct transient response, minimum error steady state, and system robustness against parameter perturbation.

Torsional oscillation suppression-oriented torque compensate control for regenerative braking of electric powertrain based on mixed logic dynamic model

This paper presents a novel torsional oscillation suppression-oriented torque compensate control for regenerative braking (TS-RTC) of electric powertrain, which is based on the gear-pair backlash and half-shaft flexibility-considered dynamic model of regenerative braking in electric powertrain (REP). According to the characteristics of transition from driving mode to regenerative braking mode (DM-to-RM), the dynamic models under different stages are transmitted into an equivalent mixed-logical dynamical (MLD) hybrid model. MLD-based hybrid braking system model and hybrid model predictive control are adopted to design the TS-RTC strategy, in which the torsional oscillation suppression-oriented cost function proved efficient in improving the regenerative braking performance during DM-to-RM process. Simulations and REP hardware in the loop test show that the fluctuation of half shaft torque are efficiently suppressed and the vehicle drivability is improved.

Hardware-in-the-Loop Testing for Protective Relays Using Real Time Digital Simulator (RTDS)

With the increasing size and complexity of power systems, it is crucial to have an effective protection system in place to ensure its reliability. One of the important components of the protection system are relays. It is important for a relay to operate dependably and securely so that any fault can be cleared in time to minimize damages to the power network. However, it is important to test a relay in a realistic environment before commissioning it to the network. Testing a relay in the actual network can be expensive with limited fault scenarios. Hence, Hardware-in-the-Loop (HIL) testing is an efficient method to perform closed-loop testing of a relay since numerous fault cases can be simulated to provide a realistic operating environment for the relay under test. This paper sheds light on the HIL testing done for protective relays using a sample distribution system using RTDS. Two SEL-351 relays have been used in this experiment, and proper settings for the relays are calculated for coordination. The paper also describes the procedure of configuring the relay and other RTDS components crucial for interfacing of the relay with RTDS. After test setup, a pre-fault, fault, and post-fault analysis was done for the system. The results obtained from these analyses are cross-checked with the event history of the two SEL-351 relays, obtained with AcSELerator Quickset software. This paper provides thorough information for researchers to replicate the presented study or to develop new HIL experiments. It can also help in developing a fundamental understanding of the HIL testing setup that can be further applied to a more complex power system.

Anti-Rollover Control and HIL Verification for an Independently Driven Heavy Vehicle Based on Improved LTR

The rollover evaluation index provides an important threshold basis for the anti-rollover control system of vehicle. Regarding the rollover risk of independently driven heavy-duty vehicles, a new rollover evaluation index is proposed, and the feasibility of the improved index was verified through hierarchical control and HIL (hardware-in-the-loop) experiments. Based on an 18-DOF spatial dynamics model of a heavy-duty vehicle, the improved LTR (load transfer rate) index was obtained to describe the dynamic change in the tire’s vertical load. It replaces the suspension force and the vertical inertia force of the unsprung load mass. It avoids the problem of directly measuring or estimating the vertical load in the LTR index. Under the conditions of fishhooking and angle stepping, three types of rollover indicators were compared, and the proposed index can more sensitively identify the likelihood of rollover. In order to apply the improved rollover index to a rollover control well, a hierarchical controller based on the identification of the slip rate of the road surface, ABS control with sliding mode, variable structure and differential braking was designed. Simulations and HIL tests proved that the designed controller can accurately predict the rollover risk and avoid the rollover in time. Under the condition of J-turning, the yaw rate, slip angle and maximum lateral acceleration are reduced by 9%, 16% and 3%, respectively; under the condition of fishhooking, the maximum yaw rate, slip angle and lateral acceleration are reduced by 12%, 18% and 3%, respectively.

A Rapid Verification System for Automatic Emergency Braking Control Algorithm of Passenger Car

The automatic emergency braking (AEB) system of the passenger car is responsible for auxiliary braking judgment and decision-making in an emergency. Due to the inevitable pressure response delay of passenger car pneumatic braking systems, a large number of verification tests should be carried out to propose appropriate strategies and algorithms. To realize the rapid verification of the AEB control algorithm, a verification system integrating software-in-the-loop (SIL) and hardware-in-the-loop (HIL) was proposed for a two-axle passenger car. It can verify the logic feasibility of the control algorithm through SIL testing, and can verify the implementation effect of the control algorithm through HIL testing. The verification system is composed of IPG, dSPACE, and a pneumatic braking bench. Considering the influence of pneumatic braking delay, it is well-matched with the actual vehicle AEB system. The AEB hierarchical control algorithm was verified under three typical test conditions. The results show that the SIL testing results of speed and relative distance are in good agreement with the HIL testing results, and the average relative deviation of relative distance is only 1.7 m. The single test time of the SIL testing is about 228 s, which can meet the requirements of rapid verification of the AEB control algorithm of the passenger car.

Component-Level Modeling of More Electric Auxiliary Power Units for Cooperative Control

Today, the more electric aircraft (MEA) concept is gaining tremendous popularity. As a key component of the MEA, a more electric auxiliary power unit (MEAPU) integrated model with high accuracy and real-time performance is essential when conducting cooperative control and hardware-in-the-loop (HIL) test research. This paper proposes a novel MEAPU integrated model consisting of a MEAPU component-level-model (CLM) and a starter-generator (SG) model. Firstly, a MEAPU CLM was built and a continuous scaling method for the component characteristic map in the CLM is proposed to improve the model’s accuracy. Then, a double winding induction starter-generator (DWISG) model based on the electromagnetic theory, which is quite time consuming, was simplified using the pulse width modulation (PWM) rectifier linearization method. Finally, considering the coupling relationship between the MEAPU CLM and DWISG, an accurate real-time MEAPU integrated model was built and its simulation results were analyzed. Compared with the test results, the error of the proposed model was less than 0.5%; meanwhile its single-step simulation time was less than 20 ms, which can meet the demands of cooperative control and HIL test research. Furthermore, the continuous scaling method and PWM rectifier linearization method were found to be effective for modeling other MEAPUs and more electric engines (MEE).

Comparison of Offline, Real-Time Models and Hardware-in-the-Loop Test Results of a Power Take-Off for Wave Energy Applications

The power take-off (PTO) of a wave energy converter (WEC) converts mechanical power extracted from the waves into electrical power. Increasing PTO performance under several operational conditions is therefore essential to reduce the levelized cost of energy of a given wave energy concept and to achieve higher levels of technology readiness. A key task in the WEC design will then be the holistic assessment of the PTO performance in combination with other subsystems. It is hence important that WEC designers are aware of the different modeling options. This paper addresses this need and presents two alternative wave-to-wire modeling approaches based on a 250 kW modular electromechanical PTO coupled to an oscillating wave surge converter (OWSC) device. The first is a detailed and accurate offline model. The second model is a simplified and faster version of the first, being adequate for rapid analyses and real-time (RT) simulation. The paper presents the benchmarking of the offline model against the RT model and the hardware-in-the-loop (HIL) tests of the PTO. The normalized root-mean-square error (NRMSE) is considered as a quantitative indicator for the measurement of real-time and HIL test results against the offline simulation. Results show that the dynamics of the offline model are well represented by the RT model with execution times up to 10 times faster. The offline model also depicts well the behavior observed in the HIL tests with the NRMSE values for the PTO position, velocity, and force above 0.90, which shows the HIL test results replicates with fidelity the dynamic behavior of the complete model. Meaningful differences are however present and highlighted in this paper. An understanding of the advantages and drawbacks of these three approaches is fundamental to properly design a WEC during its project cycle and validate PTO concepts with a certain level of simplification.