dSPACE Real-time Simulation Research Articles

Development and verification of model predictive control strategy for selective catalytic reduction with rapid prototyping

The International Maritime Organization has set forth strict regulations about the NOx emission limit of ships to address the pollution problem in the transportation sector. Selective catalytic reduction (SCR) is the most effective post-engine means to reduce emission, and the control of urea spray critically affects the SCR performance. This paper developed a predictive control strategy of the SCR system based on the state space model. Specifically, the block model of the SCR reactor was established based on the reaction mechanism of the SCR system, and the unknown model parameters were identified. Rapid prototyping of the SCR system was carried out using the dSPACE real-time simulation platform to optimize the control under steady-state conditions. The catalyst ammonia coverage was set as the control target to maximize the NOx conversion rate while maintaining the NH3 escape at the outlet less than 10 ppm. The cyclic test results showed that the control strategy can quickly respond to external disturbance and modify the control target to keep the ammonia coverage rate within the target range, to thus achieve high NOx conversion rate while maintaining the required ammonia escape.

A study on a vehicle semi-active suspension control system based on road elevation identification.

A semi-active suspension system can effectively improve vehicle ride comfort and handling stability, and the active detection of road information is key to achieving semi-active suspension. To improve the road elevation perception ability of vehicles, this study proposes a continuous multiple scanning recursive matching algorithm based on a single-line LIDAR sensor. Radar recursive scanning is used to obtain the multiple superposition data of echo signals, and coordinate matching is realized between historical scanning data and current scanning data. Simultaneously, the sensor height deviation and pitch angle deviation of the sensors are regressed to obtain an accurate pavement elevation. Considering the control effect of the active vehicle suspension, a vehicle suspension model with seven degrees of freedom is established. The semi-active suspension controller is constructed using a diagonal recursive neural network algorithm, and the neural network weight is trained using a genetic algorithm. In addition, a preview diagonal recursive neural network control strategy for semi-active suspension, based on the combination of road elevation information, is proposed. The results of a hardware-in-the-loop co-simulation, which was conducted based on the Simulink control model and dSPACE real-time simulation, revealed that the ride comfort and stability of the vehicle were improved owing to a preview of the elevation information of the road ahead and the active adjustment of the shock absorber of the suspension system.

FPGA‐based hardware‐in‐the‐loop real‐time simulation implementation for high‐speed train electrical traction system

The hardware-in-the-loop (HIL) real-time simulation for high-speed train electrical traction system aims to reduce the design cost and speed up control verification process of algorithms in the developmental stage of the traction control unit. In this study, based on the dSPACE real-time simulator, the multiple-simulator, multiple-simulation step of HIL real-time simulation system is first built. Second, for the associated discrete circuit modelling method, an optimisation method is proposed to minimise the switching loss and improve the simulation accuracy by selecting the optimal discrete-time switch admittance parameter, G S . To decrease the computational burden for field-programmable gate array (FPGA), a decoupling method without simulation latency is presented to reduce the matrix dimension of the system model. Finally, the real-time simulation models of electrical traction system are realised by CPU + FPGA-based simulator, in which the power electronics converter models are computed in FPGA with a fixed 100 ns time-step. The validity and reliability of the real-time simulation system is verified by the HIL simulation and experimental results, which indicate that the real-time HIL simulation at the nanosecond level improves the accuracy essentially.

Islanded Microgrid Frequency Regulations Concerning the Integration of Tidal Power Units: Real-Time Implementation

This brief proposes a new optimal intelligent controller for the secondary load frequency control (SLFC) in islanded microgrids (MGs). Particularly, this brief is applied a precise model of the tidal power generation system for the SLFC in the stand-alone MG. Moreover, in order to reduce the cost of energy storage (ES) devices in the MG, vehicle-to-grid (V2G) technology has utilized as a new idea to overcome this difficulty. Hence, a fractional type-2 fuzzy P+ID controller is applied to have a robust balance between generation and demand. Furthermore, it is quite clear that optimal tuning of the controller’s parameters can cause a significant effect on the performance of the whole of the system. Consequently, a new heuristic optimization algorithm, entitled sine–cosine, is used to find the best value of the proposed controller’s parameters. Finally, by using real-data, the performance and robustness of the suggested controller over other controller techniques have examined by the dSPACE real-time simulator.

Research on instantaneous optimal control of the hybrid electric vehicle with planetary gear sets

Power-split hybrid electric vehicle (HEV), mainly adopting the planetary power coupling mechanism, is superior in improving the fuel economy because the engine speed and torque are decoupled from those of the wheels. Focusing on a power-split HEV with dual-planetary gear sets, this paper establishes an instantaneous optimal control to regulate its power flow. Firstly, simulation-oriented models are established, including the coupling mechanism, the engine, the electrical machines and the battery. Secondly, feasible operation modes of the vehicle are analyzed. Also, the torque and speed equations between the engine and motors are obtained. On the basis of the above, the instantaneous optimization strategy, adaptive equivalent fuel consumption minimization strategy (A-ECMS), is designed, which is developed from the equivalent fuel consumption minimization strategy. The optimization strategy is of high robustness to different driving cycles. To realize the engine speed tracking, a PI controller is introduced. At last, the control effects of A-ECMS are compared with the effects of the engine optimal operating line control strategy. The effectiveness and rationality of two strategies are tested in the dSPACE real-time simulator. Test results under different driving scenarios prove that the A-ECMS is of better performance in ensuring the HEV fuel economy and the battery charging sustainability.

Research on a New Three-port Converter Operating Principle and Control Strategy

The three-port DC/DC converter can connect two different energy storage devices, and can reduce the number of DC/DC converters used, optimize the system structure, and achieve low volume quality, high integration, and high efficiency of energy storage systems. This paper proposes a new three-level and three-port DC/DC converter, which has the advantages of small voltage resistance and high efficiency of the switch tube. This paper focuses on the analysis of the topological structure and working principle of the new converter. A novel control strategy for dynamically determining the duty cycle is proposed for the novel converter’s flying capacitor voltage equalization control. Finally, the feasibility of the working principle and the control strategy are verified by DSPACE and Typhoon real-time simulation platform.

Design of Hardware-In-Loop Simulation Platform for Air Suspension Systems

With the development of control algorithms and structural features in the control system, the hardware-in-loop simulation technology has been widely used after unremitting research and exploration on the basis of off-line simulation. In this paper, the dSPACE real-time simulation system is used to design and develop a hardware loop simulation experiment platform for an air suspension. CarSim vehicle model and suspension control algorithms can be run in the real time. Based on the dSPACE realtime simulation platform mentioned above, a real-time monitoring interface and control program are developed to complete the test of the sliding mode control method of the 1/4 air suspension.

Sensor fault diagnosis and processing for a two-speed AMT for pure electric vehicles

In shifting process for the two-speed AMT (automated manual transmission) in this paper, the position of synchronizer sleeve is reflected by output signal of an angular displacement sensor, therefore, the normal operation of the sensor is the key to complete shifting accurately and reliably. To improve the fault-tolerant ability of two-speed AMT for electric vehicles, the operation principle of the shifting actuator and the shifting process of the two-speed AMT are analyzed. A signal revised strategy and a vehicle failure mode are proposed for the sensor signal drift and sensor fault respectively. A test bed based on dSPACE real time simulation was set up for the two-speed AMT and the sensor fault diagnosis and processing strategy was verified by experiment. The experiment results indicate that the proposed strategy can be achieved under the simulation of sensor signal drift and sensor fault, improving the reliability of the AMT.

Design of an Integrated Vehicle Chassis Control System with Driver Behavior Identification

An integrated vehicle chassis control strategy with driver behavior identification is introduced in this paper. In order to identify the different types of driver behavior characteristics, a driver behavior signals acquisition system was established using the dSPACE real-time simulation platform, and the driver inputs of 30 test drivers were collected under the double lane change test condition. Then, driver behavior characteristics were analyzed and identified based on the preview optimal curvature model through genetic algorithm and neural network method. Using it as a base, an integrated chassis control strategy with active front steering (AFS) and direct yaw moment control (DYC) considering driver characteristics was established by model predictive control (MPC) method. Finally, simulations were carried out to verify the control strategy by CarSim and MATLAB/Simulink. The results show that the proposed method enables the control system to adjust its parameters according to the driver behavior identification results and the vehicle handling and stability performance are significantly improved.

Researching on General Modeling Method for a Class of Spoke Inclined Parallel Mechanism

With the deepening of researching on parallel mechanism, a variety of parallel mechanism and corresponding modeling method are presented, but these methods are not universal. So this paper deals with a class of spoke inclined parallel mechanism as the object, trying to get the general modeling method of kinematics and dynamics, which will pro- vide convenient on this kind of parallel mechanism. Kinematics model with inverse selection criteria is established using geometric method, dynamics model is established by Lagrange method, then the mapping relationship between input- output displacement and driving force of the parallel mechanism are presented; Set 45° angle as an example, the prototype of spoke inclined parallel mechanism is developed based on dSPACE real-time simulation system, the validation experi- ments and rotation performance test experiments are done using the methods combining the theoretical modeling and ex- perimental validation. The experimental results show that the mathematical model is correct, the parallel mechanism has the advantage of low inertia and large angle, the maximum angle of the prototype can reach 51.4°. The parallel mecha- nism in this paper can be used for automobile coating and manufacturing, and the research will lay the foundation for fur- ther application in mechanical industry.

Real-Time Implementation in DSPACE of Rotor Magnetic Field Control of Bearingless Induction Motor

A bearingless induction motor is a strong coupled complex system, the decoupling control of torque and radial suspension force is the premise of the stable operation of the bearingless induction motor. In this paper, the principle of bearingless induction motor is expounded. The magnetic mathematical models of bearingless induction motor are created. The rotor field oriented control strategy is designed. The control strategy is validated with Matlab/simulink. Real-time simulation model based on dSPACE is given and the platform based on dSPACE is constructed. The results show that this method has good decoupling control performance. The actual system development and experiment process confirms that the dSPACE real-time simulation platform can shorten the development time and facilitate the development process, and save costs during the design and test period.

DOB-based piezoelectric vibration control for stiffened plate considering accelerometer measurement noise

This paper presents a composite control strategy for the active suppression of vibration due to the unknown disturbances, such as external excitation, harmonic effects and control spillover, as well as high-frequency accelerometer measurement noise in the all-clamped stiffened plate. The proposed composite control action based on the modal approach, consists of two contributions including feedback part and feedforward part. The feedback part is the well-known PID controller, which is widely used to increase the structure damping and improve its dynamic performance close to the resonance frequencies. In order to get better performance for vibration suppression, the weight matrixes is optimized by chaos sequence. Then an improved disturbance observer (IDOB) as the feedforward compensation part is developed to enhance the vibration suppression performance of PID under various disturbances and uncertainties. The proposed IDOB can simultaneously estimate the various disturbances dynamically as well as measurement noise acting on the system and suppress them by feedforward compensation design. A rigorous analysis is also given to show why the IDOB can effectively suppress the unknown disturbances and measurement noise. In order to verify the proposed composite control algorithm (IDOB-PID), the dSPACE real-time simulation platform is used and an experimental platform for the all-clamped stiffened plate active vibration control system is set up. The experimental results demonstrate the effectiveness, practicality and strong anti-disturbances ability of the proposed control strategy.

Composite multi-modal vibration control for a stiffened plate using non-collocated acceleration sensor and piezoelectric actuator

A novel active method for multi-mode vibration control of an all-clamped stiffened plate (ACSP) is proposed in this paper, using the extended-state-observer (ESO) approach based on non-collocated acceleration sensors and piezoelectric actuators. Considering the estimated capacity of ESO for system state variables, output superposition and control coupling of other modes, external excitation, and model uncertainties simultaneously, a composite control method, i.e., the ESO based vibration control scheme, is employed to ensure the lumped disturbances and uncertainty rejection of the closed-loop system. The phenomenon of phase hysteresis and time delay, caused by non-collocated sensor/actuator pairs, degrades the performance of the control system, even inducing instability. To solve this problem, a simple proportional differential (PD) controller and acceleration feed-forward with an output predictor design produce the control law for each vibration mode. The modal frequencies, phase hysteresis loops and phase lag values due to non-collocated placement of the acceleration sensor and piezoelectric patch actuator are experimentally obtained, and the phase lag is compensated by using the Smith Predictor technology. In order to improve the vibration control performance, the chaos optimization method based on logistic mapping is employed to auto-tune the parameters of the feedback channel. The experimental control system for the ACSP is tested using the dSPACE real-time simulation platform. Experimental results demonstrate that the proposed composite active control algorithm is an effective approach for suppressing multi-modal vibrations.

DSPACE Implication of HILS for Mill Control System

Dspace HILS platform is used to realize the real-time test of the mill control system.In this platform, a real controller is the part of the control system. DSPACE real-time simulation and computer real-time running control the object model to virtual out a rolling mill, which realizes the mill the real-time closed-loop test of control system.Yanshan University 300 reversible rolling mill as the object of experimental platform is established and verifies the feasibility and validity of the simulation platform.

Hardware-in-the-Loop Simulation and Flight Experimentation of the Control System on a Small Solid Rocket

By using the Perturbation Theory and solidification coefficient method, based on the interpolation parameters for optimal control feedback matrix, the design of optimal roll control system for a small solid rocket is achieved. The hardware-in-the-loop simulation platform built with DSPACE real-time simulator and high-precision three axis turntable is designed to validate the optimal control law. As for no feedback device of the steering gear, the radios are used to transfer the signals between the devices in the closed loop simulation system. Finally, through the flight-testing, the results confirm a good stability of the roll control system and the high reliability of the hardware-in-the-loop simulation platform.

Vibration Suppression of Flexible Parallel Manipulator Based on Sliding Mode Control with Reaching Law

A discrete sliding mode control based on reaching law is investigated to suppress vibration of high-speed flexible manipulator. The finite element method and experimental modal test is applied to obtain the dynamic model of the system. Due to the influence from uncertain external disturbances and measurement noise, and uncertain parameters, sliding mode control has invariance of the sliding mode. The discrete sliding mode control approach with reaching law is applied to design the vibration controller which enables the system to be zero state as the system states are away from the equilibrium one due to external disturbances. The discrete Kalman filtering technique is employed to construct state estimator because the state variables cannot be directly measured. The first three natural frequencies and damping ratio are obtained by using experimental modal testing. The experimental control system is constructed and experimental validation is carried out using dSPACE real-time simulation system and MATLAB/Simulink. The experimental results showed that the proposed controller can effectively suppress the vibration response of the flexible manipulator.

Multi-modal vibration control using amended disturbance observer compensation

Piezoelectric panel is a fundamental element in many structures characterised with multi-variables, coupling and uncertain external excitation. Many advanced active control schemes have been reported for the multi-modal of piezoelectric structure. However, these control schemes, including the multi-loop PID method usually cannot achieve satisfying performance in the presence of strong external disturbances and coupling effects. To this end, an amended disturbance observer (DOB) based on multi-loop PID scheme is developed to control a two-mode piezoelectric panel. The system considered here is with lumped disturbances including external disturbances, such as the variations of the output of the modal and the external excitation, and internal disturbances, such as coupling effects. The proposed control approach consists of two compound controllers, and each controller includes a PID feedback part and a feed-forward compensation part based on DOB for disturbances. In order to obtain a better vibration suppressing performance, a chaos optimisation method based on Logistic map and a new transient performance function is designed to tune the parameters of PID controller. A rigorous analysis is also given to show why the DOB can effectively suppress the variations. At last, in order to verify the proposed algorithm, the dSPACE real-time simulation platform is used and an experimental platform for the all-clamped stiffened panel structure active vibration control is set up. The simulation and experiment results demonstrate that the proposed method has a much better vibration suppressing property with almost the same input voltage than the multi-loop PID method in the piezoelectric panel.

Design of Hardware-in-Loop Simulation System for Unmanned Aerial Vehicle

Hardware-in-loop simulation (HILS) is an important approach to the development of Unmanned Aerial Vehicle (UAV) systems. In this paper, a complete HILS system for UAV was constructed based on the dSPACE real-time simulator. To simulate the real world situation, problems such as the GPS signal and accelerometer signal imitation were addressed in the dSPACE framework. The HILS simulation of a UAV’s take-off process was exhibited with comparison to the digital simulation; the results show effectiveness of the proposed HILS system.

Hardware-in-the-Loop Simulation of Speed-Adjusting System for DC Motor Based on dSPACE

Based on dSPACE real-time simulation system and LabVIEW measuring system, semi-physical simulation platform of DC motor speed-adjusting system was established. Fuzzy PID algorithm was designed based on analyzing fuzzy control and PID control for speed-adjusting system. The simulation results show that compared to standard PID algorithm, fuzzy PID algorithm improves the performance of speed-adjusting system for DC motor. On this basis, the speed-adjusting system was developed based on ATmega128 single-chip and original algorithm. Compared with simulation speed-adjusting system, there is no obvious difference on response characteristics.