This paper presents a novel motion control strategy based on model predictive control (MPC) for distributed drive electric vehicles (DDEVs), aiming to simultaneously control the longitudinal and ...lateral motion while considering efficiency and the driving feeling. Initially, we analyze the vehicle's dynamic model, considering the vehicle body and in-wheel motors, to establish the foundation for model predictive control. Subsequently, we propose a model predictive direct motion control (MPDMC) approach that utilizes a single CPU to directly follow the driver's commands by generating voltage references with a minimum cost function. The cost function of MPDMC is constructed, incorporating factors such as the longitudinal velocity, yaw rate, lateral displacement, and efficiency. We extensively analyze the weighting parameters of the cost function and introduce an optimization algorithm based on particle swarm optimization (PSO). This algorithm takes into account the aforementioned factors as well as the driving feeling, which is evaluated using a trained long short-term memory (LSTM) neural network. The LSTM network labels the response under different weighting parameters in various working conditions, i.e., "Nor", "Eco", and "Spt". Finally, we evaluate the performance of the optimized MPDMC through simulations conducted using MATLAB and CarSim software. Four typical scenarios are considered, and the results demonstrate that the optimized MPDMC outperforms the baseline methods, achieving the best performance.
Traditional strategies for model predictive direct speed control of permanent-magnet synchronous motors are known to be vulnerable to voltage errors. In this paper, we present a novel approach that ...compensates for voltage errors arising from inverter nonlinearity and bus voltage uncertainties, while remaining unaffected by parameter errors. Initially, we conducted a detailed analysis to assess the impact of inverter nonlinearity and bus voltage uncertainties. Subsequently, we proposed a voltage error compensation strategy based on bus voltage identification. Using this strategy, the identified voltage error is effectively compensated within candidate voltage vectors. To validate the effectiveness of our proposed method, we conducted comprehensive experiments. The results demonstrate notable improvements compared with traditional model predictive control. Specifically, our method successfully reduces the total harmonic distortion of phase currents from 23.2% and 49.6% to 11.6% and 13.9%, respectively. Additionally, it accurately identifies voltage errors, even in the presence of parameter errors. Overall, our proposed method presents a robust and reliable solution for addressing voltage errors, thereby enhancing the performance and stability of the system.
For the motion of distributed drive electric vehicles, this paper deigns a novel motion control strategy based on model predictive control, which can control the longitudinal and lateral motion ...simultaneously. Different with traditional strategies containing one vehicle controller and four motor controllers, this strategy treats the vehicle and its in-wheel motors as one control object and uses only one controller to realize motion control, so that control costs are reduced and the handling performance is improved. First, an improved unified model of the vehicle and in-wheel motors is established to predict future states. Considering different time constants in vehicle dynamic system and motor electrical system, coupling predictions are analyzed in detail and a linear model is proposed to simplify the complex computation. Then, based on the fact that inverters of in-wheel-motor systems have discrete and finite voltage vectors, a model predictive direct motion control strategy is proposed. A cost function is designed to find out optimal voltage vectors which make vehicle follow the desired motion and meet constrains. Finally, to deal with huge amount of calculation and over-actuation problem caused by four in-wheel-motor systems, a deadbeat solution is applied to optimize the optimal voltage vectors calculation. Simulations under the proposed and traditional strategies are carried out, in which that the proposed strategy can realize the vehicle motion control well in different directions, and improve the vehicle handling performance. A practical implementation method is also provided experimentally to realize the strategy on four-motor system.
This paper presents a centralized disturbance suppression strategy for distributed drive electric vehicles which is based on model predictive direct motion control. This strategy is capable of ...addressing issues such as parameter uncertainties and external disturbances in vehicles. Firstly, the paper provides a brief introduction to model predictive direct motion control. Secondly, it analyzes the impact of vehicle parameter uncertainties and external disturbances on the mathematical model. Finally, a centralized disturbance suppression strategy based on a sliding mode observer is proposed. Simulation results demonstrate that this strategy exhibits excellent disturbance rejection capabilities.
The paper studies a novel fault-tolerant strategy of the modular permanent magnet synchronous motor under open-circuit faults, which is called as the extended open-circuit fault-tolerant control ...(EOCFTC) strategy. The faulty modular motor based on the EOCFTC strategy can achieve the high fault-tolerance and maximum output torque capability by making the most of the remaining healthy phases. First, the mathematical model of the modular motor with n modules is described. Then based on the characteristics of the modular motor, a novel winding reconstruction strategy is proposed to deal with multiphase open-circuit faults in different modules. All remaining healthy phases are reasonably reconstructed according to the maximum output torque principle. Then these new modules can operate well by employing the armature magnetomotive force (MMF) compensation and the field-orientated control (FOC) strategy. Finally, all cases of open-circuit faults and the corresponding processing methods are discussed. The extreme case of open-circuit faults is described in detail, which shows the high fault-tolerance of the modular motor with the EOCFTC strategy. The experimental results verify the rationality and feasibility of the EOCFTC strategy on a two-module modular motor.
To study the transcriptional regulation of the structural components Hcp1 by H-NS in Vibrio parahaemolyticus.
Expression of Hcp1 in the wide-type (WT) strain and hns mutant (Δhns) were detected by ...Western blot using rabbit anti-Hcp1 polyclonal antibodies. Total RNAs were extracted from WT and Δhns strains. Quantitative RT-PCR was carried out to calculate the transcriptional variation of hcp1 between WT and Ahns strains, and then primer extension assay was used to detect the transcription start site and the promoter activity (the amount of primer extension product) of hcp1 in WT and Δhns. The entire promoter region of hcp1 was amplified by PCR with ExTaq™ DNA polymerase using WT genomic DNA as the template. The over-expressed His-H-NS was purified under native conditions with nickel loaded HiTrap Chelating Sepharose columns (Amersham). Electrophoretic mobility shift assay (EMSA) was applied to analyze the DNA-binding activity of His-H-NS to hcp1 promoter region in vitro.
Western blot and quantitative RT-PCR re
•Eco-friendly PAN composite was prepared by using biomass materials.•PAN composite had excellent flame retardancy and antibacterial properties.•The modification is environmentally friendly, simple ...process and easy to prepare.
To improve the fire safety of polyacrylonitrile (PAN) and expand its application area, flame retardant and antibacterial PAN composite was prepared by a simple and environmentally friendly method. First, AgNO3 and NaBH4 solutions were added to the microcrystalline cellulose (MCC) aqueous suspension to prepare MCC loaded Ag nanoparticles (Ag NPs) (MCC/Ag) by in situ reduction. Then, MCC/Ag was mixed in PAN solution to prepare MCC/Ag/PAN composite, which was then phosphorylated by phytic acid (PA) to obtain flame retardant MCC/Ag/PAN composite (FR-MCC/Ag/PAN). FR-MCC/Ag/PAN could achieve self-extinguishing with limiting oxygen index (LOI) value of 36.8 %. The thermogravimetric results showed that phosphorus-containing acids accelerated the char-forming ability of FR-MCC/Ag/PAN, and the final char residue was up to 29.76 % in air atmosphere. Thermogravimetric coupled with Fourier transform infrared spectroscopy (TG-FTIR) and scanning electron microscope (SEM) showed that FR-MCC/Ag/PAN formed an expanded and dense char layer after combustion, suppressing the release of low molecular toxic gases. Moreover, FR-MCC/Ag/PAN showed favorable inhibition of Escherichia coli (E. coli) and Staphylococcus aureus (S. aureus). This work proposed a novel method for developing flame retardant and antibacterial PAN material, which broadened the application field of polyacrylonitrile.
•Flame retardant PAN fibers were prepared based on amination and mannich reaction.•The modified PAN fibers had good flame retardant durability.•The modification endowed PAN fibers improved mechanical ...properties.•Flame retardancy and improved tensile strength expanded its practical application.
To improve the flame retardancy, smoke suppression and mechanical properties of polyacrylonitrile (PAN) fiber, it was first modified with diethylenetriamine to prepare the aminated PAN fiber (A-PAN). Second, diethyl phosphite (DEP) was grafted onto the A-PAN to fabricate flame retardant PAN fiber (DEP-A-PAN). XPS and FTIR analysis confirmed that phosphorus and nitrogen elements were covalently bonded to the surface of PAN fiber. TGA revealed that the incorporation of DEP promoted char formation of PAN matrix and suppressed the thermal degradation. DEP-A-PAN exhibited a significantly reduced peak heat release rate (pHRR) compared to the control sample. Moreover, the limiting oxygen index (LOI) of DEP-A-PAN was up to 34.3 %, and remained at 26.6 % even after 50 laundering cycles (LCs), demonstrating excellent durable flame retardancy. Interestingly, DEP-A-PAN exhibited improved tensile strength of 2.97 cN/dtex. This work developed a simple and feasible method for preparing mechanical-enhanced flame retardant and smoke suppressive PAN fiber, which could be large-scale preparation.
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•A novel six-armed and star-type flame retardant (SCCP) was synthesized.•Flame retardant PAN was prepared by SCCP and chitosan chelated with Cu2+.•Modified PAN has flame retardancy, ...smoke suppression and antibacterial properties.•The modification is practical, green and environmentally friendly.
In this work, a six-armed star-type flame retardant (SCCP) contained phosphorus, nitrogen and sulfur contents was developed, which was then combined with chitosan (CS) to chelate Cu2+ (SCCP@CS-Cu) and blend with polyacrylonitrile (PAN) to produce flame retardant and antibacterial PAN composite (PAN/SCCP@CS-Cu). TG showed that the residual char of PAN/SCCP@CS-Cu in air and nitrogen atmosphere was as high as 16.41 % and 48.48 % at 800 °C, respectively, which were greater than that of PAN. The LOI value of PAN/SCCP@CS-Cu improved to 33.0 % and the peak heat release rate (PHRR) and total heat release (THR) of the composite were all greatly reduced. In addition, the total smoke production (TSP) of PAN/SCCP@CS-Cu decreased by 73.6 % compared to the control sample. Interestingly, the antibacterial properties of PAN/SCCP@CS-Cu against E. coli and S. aureus reached 98.45 % and 99.33 %. This work provides an insight into developing an environmentally friendly PAN composite with flame retardancy, smoke suppression and antibacterial properties, greatly expanding its application field.
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