Pub Date : 2024-07-25DOI: 10.1177/09544070241257556
Cheng Lin, Huimin Liu, Xiao Yu, Peng Xie
Collaborative optimization of the coupling parameters of powertrain is essential to improve the performance of electric vehicles. However, complex coupling relationships and multi-objective trade-offs bring challenges to traditional heuristic optimization algorithms, limiting the exploitation of system performance. To improve optimization accuracy and the performance of vehicles, a global parameter optimization framework for multi-power source systems is proposed. Specifically, the optimization framework consists of three layers, the middle and bottom layers respectively perform multi-disciplinary and multi-objective collaborative optimization of the coupling parameters to obtain a Pareto front formed by the optimal combination of parameters. Furthermore, the decision layer utilizes the Technique for Order Preference by Similarity to Ideal Solution to perform a comprehensive evaluation of the solution on the Pareto front to scientifically obtain the best solution and the weight coefficient range. The simulation results demonstrate that the optimized optimal solution improves dynamic performance by 15.77% while reducing operating costs by 7.37% compared to the initial parametric solution, resulting in a significant improvement in vehicle economy. Meanwhile, the parameter optimization design regularities of the dual-motor system are summarized.
{"title":"A multi-objective coupling parameter hierarchical optimization framework for a novel dual-motor powertrain system of electric vehicle","authors":"Cheng Lin, Huimin Liu, Xiao Yu, Peng Xie","doi":"10.1177/09544070241257556","DOIUrl":"https://doi.org/10.1177/09544070241257556","url":null,"abstract":"Collaborative optimization of the coupling parameters of powertrain is essential to improve the performance of electric vehicles. However, complex coupling relationships and multi-objective trade-offs bring challenges to traditional heuristic optimization algorithms, limiting the exploitation of system performance. To improve optimization accuracy and the performance of vehicles, a global parameter optimization framework for multi-power source systems is proposed. Specifically, the optimization framework consists of three layers, the middle and bottom layers respectively perform multi-disciplinary and multi-objective collaborative optimization of the coupling parameters to obtain a Pareto front formed by the optimal combination of parameters. Furthermore, the decision layer utilizes the Technique for Order Preference by Similarity to Ideal Solution to perform a comprehensive evaluation of the solution on the Pareto front to scientifically obtain the best solution and the weight coefficient range. The simulation results demonstrate that the optimized optimal solution improves dynamic performance by 15.77% while reducing operating costs by 7.37% compared to the initial parametric solution, resulting in a significant improvement in vehicle economy. Meanwhile, the parameter optimization design regularities of the dual-motor system are summarized.","PeriodicalId":54568,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part D-Journal of Automobile Engineering","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784397","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-25DOI: 10.1177/09544070241264867
Shaikh Mosin K, Adik Yadao
Vibration of automobile vehicles is the important issue in the entire vehicle design process as it affects the comfort level and the overall image of a vehicle, an experimental evaluation and prediction of vibration level of the vehicle in stationary and driving conditions are often necessary. This paper delves in to a numerical and experimental investigation of vibration and response optimization of a car chassis with peak acceleration and peak amplitude level of vibration as a response parameter in vertical motion. These response parameters were obtained numerically by developing a mathematical model of car and equation of motion. Newmark Beta method used to solve the equation of motion to get the values of response parameters in MATLAB software. For the experimental investigation of the response parameters a car with monocoque chassis, three cylinder engine, Macpherson front suspension and twist beam rear suspension with coil spring considered and FFT analyzer used for the data collection of the response parameters, FFT analyzer works on the fast Fourier transform algorithm. Comparative analysis between the numerical and experimental investigated values of response parameters shows the minimum error of 0.6035% and average error of 2.81% at various points on chassis; it shows the precision of the mathematical model and practical car model. To optimize the performance index of response parameters Fractional factorial design of experiment (DOE) method applied with six factors and two levels. The main effect analysis, analysis of contribution, analysis of variance and backward elimination method were applied in fractional factorial design. Regression equation for the response parameters were obtained with two level six factor fractional factorial design for the vibration level prediction. The comparative analysis of the response parameter levels before and after the optimization shows the reduction of 65.61% in peak acceleration level and reduction of 17.70% in the peak amplitude level of a car chassis with respect to change in the driving speed. The design and optimization method proposed in this study has a significant effect on the vibration reduction of the car chassis which provides a reference for the optimization of the vibration level to improve the performance of car suspension.
{"title":"Numerical and experimental investigation of vibration and response optimization of a car chassis with effect of changing driving speed","authors":"Shaikh Mosin K, Adik Yadao","doi":"10.1177/09544070241264867","DOIUrl":"https://doi.org/10.1177/09544070241264867","url":null,"abstract":"Vibration of automobile vehicles is the important issue in the entire vehicle design process as it affects the comfort level and the overall image of a vehicle, an experimental evaluation and prediction of vibration level of the vehicle in stationary and driving conditions are often necessary. This paper delves in to a numerical and experimental investigation of vibration and response optimization of a car chassis with peak acceleration and peak amplitude level of vibration as a response parameter in vertical motion. These response parameters were obtained numerically by developing a mathematical model of car and equation of motion. Newmark Beta method used to solve the equation of motion to get the values of response parameters in MATLAB software. For the experimental investigation of the response parameters a car with monocoque chassis, three cylinder engine, Macpherson front suspension and twist beam rear suspension with coil spring considered and FFT analyzer used for the data collection of the response parameters, FFT analyzer works on the fast Fourier transform algorithm. Comparative analysis between the numerical and experimental investigated values of response parameters shows the minimum error of 0.6035% and average error of 2.81% at various points on chassis; it shows the precision of the mathematical model and practical car model. To optimize the performance index of response parameters Fractional factorial design of experiment (DOE) method applied with six factors and two levels. The main effect analysis, analysis of contribution, analysis of variance and backward elimination method were applied in fractional factorial design. Regression equation for the response parameters were obtained with two level six factor fractional factorial design for the vibration level prediction. The comparative analysis of the response parameter levels before and after the optimization shows the reduction of 65.61% in peak acceleration level and reduction of 17.70% in the peak amplitude level of a car chassis with respect to change in the driving speed. The design and optimization method proposed in this study has a significant effect on the vibration reduction of the car chassis which provides a reference for the optimization of the vibration level to improve the performance of car suspension.","PeriodicalId":54568,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part D-Journal of Automobile Engineering","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141786238","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-25DOI: 10.1177/09544070241261107
Yingzhe Kan, Shuangyi Xie, Qin Yin, Wei Jiang, Min Yang, Run Qian
The power reflux hydrodynamic transmission system (PRHTS) has the advantages of flexible transmission, low-speed torque multiplication, adaptive adjustment of speed ratio to external load, and improved torque converter (TC) transmission efficiency. Therefore, it is highly suitable for wheel loaders. Wheel loaders usually work in harsh environments with complex and changing working conditions, and static power matching makes it challenging to fully utilize wheel loaders’ performance. In response to the above issues, this paper proposes a dynamic power matching optimization design method for PRHTS with capacity adjustment gear (CAG) based on wheel loader. The optimization design method obtains data through V-shaped working condition experiments of the wheel loader, and conducts clustering analysis on the data to obtain high-frequency kinematic segments and their characteristic parameters. On this basis, combined with the analysis of the working principle of PRHTS, the system structural parameters are optimized and designed. Compared with static power matching, the dynamic power matching optimization design method increases the average traction force by 4.9 kN, improves the transmission efficiency by 2.6%, reduces the average fuel consumption rate by 3.66 g (kW·h)−1, and reduces the fuel consumption per V-cycle by 27.7 ml in V-shaped working conditions.
动力回流液力传动系统（PRHTS）具有传动灵活、低速扭矩倍增、根据外部负载自适应调节速比、提高变矩器（TC）传动效率等优点。因此，它非常适合轮式装载机。轮式装载机通常工作在环境恶劣、工况复杂多变的环境中，静态动力匹配使轮式装载机性能的充分发挥面临挑战。针对上述问题，本文提出了一种基于轮式装载机的带容量调节齿轮（CAG）的 PRHTS 动态功率匹配优化设计方法。该优化设计方法通过轮式装载机的 V 型工况实验获取数据，并对数据进行聚类分析，得到高频运动线段及其特征参数。在此基础上，结合对 PRHTS 工作原理的分析，对系统结构参数进行优化设计。与静态功率匹配相比，动态功率匹配优化设计方法使平均牵引力提高了 4.9 kN，传动效率提高了 2.6%，平均燃料消耗率降低了 3.66 g (kW-h)-1，在 V 型工况下每 V 循环燃料消耗量降低了 27.7 ml。
{"title":"Dynamic power matching for wheel loader based on power reflux hydrodynamic transmission system","authors":"Yingzhe Kan, Shuangyi Xie, Qin Yin, Wei Jiang, Min Yang, Run Qian","doi":"10.1177/09544070241261107","DOIUrl":"https://doi.org/10.1177/09544070241261107","url":null,"abstract":"The power reflux hydrodynamic transmission system (PRHTS) has the advantages of flexible transmission, low-speed torque multiplication, adaptive adjustment of speed ratio to external load, and improved torque converter (TC) transmission efficiency. Therefore, it is highly suitable for wheel loaders. Wheel loaders usually work in harsh environments with complex and changing working conditions, and static power matching makes it challenging to fully utilize wheel loaders’ performance. In response to the above issues, this paper proposes a dynamic power matching optimization design method for PRHTS with capacity adjustment gear (CAG) based on wheel loader. The optimization design method obtains data through V-shaped working condition experiments of the wheel loader, and conducts clustering analysis on the data to obtain high-frequency kinematic segments and their characteristic parameters. On this basis, combined with the analysis of the working principle of PRHTS, the system structural parameters are optimized and designed. Compared with static power matching, the dynamic power matching optimization design method increases the average traction force by 4.9 kN, improves the transmission efficiency by 2.6%, reduces the average fuel consumption rate by 3.66 g (kW·h)<jats:sup>−1</jats:sup>, and reduces the fuel consumption per V-cycle by 27.7 ml in V-shaped working conditions.","PeriodicalId":54568,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part D-Journal of Automobile Engineering","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784341","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-25DOI: 10.1177/09544070241265400
Fei Dong, Jiu Rui Zhao, Wen Yu Zhang
Being a crucial thermal management component in an internal combustion engine, the wettability of the piston gallery significantly influences heat transfer performance. This study deeply investigates the impact of the piston gallery’s wettability on heat transfer performance through numerical simulation. Adjusting the wettability parameter, specifically the contact angle, resulted in the observation of varied droplet patterns on the surface of gallery. Surface wettability directly influences oil distribution and adhesion on the piston surface, consequently impacting the piston’s cooling effectiveness. Optimizing the wettability of the oil cavity is expected to improve the cooling efficiency of the piston, contributing to an overall performance improvement. The numerical study revealed that a surface with a certain degree of hydrophilicity facilitates uniform droplet distribution on the surface of the gallery, forming a film-like oil droplet. Such a film of oil droplets effectively enhances heat transfer efficiency, with a well-wetted surface promoting effective contact between the oil and piston surface for more efficient heat transfer. Conversely, a highly hydrophobic surface leads to droplet self-aggregation in the gallery, hindering effective heat dissipation from the piston. Poor wettability prevents uniform oil adhesion to the piston surface, resulting in decreased heat transfer efficiency. To summarize, the wettability of the piston gallery significantly influences heat transfer performance. Optimizing surface wettability enhances piston cooling, thereby improving overall internal combustion engine performance.
{"title":"Numerical study of the influence of wetting properties on flow characteristics and heat transfer in piston cooling gallery","authors":"Fei Dong, Jiu Rui Zhao, Wen Yu Zhang","doi":"10.1177/09544070241265400","DOIUrl":"https://doi.org/10.1177/09544070241265400","url":null,"abstract":"Being a crucial thermal management component in an internal combustion engine, the wettability of the piston gallery significantly influences heat transfer performance. This study deeply investigates the impact of the piston gallery’s wettability on heat transfer performance through numerical simulation. Adjusting the wettability parameter, specifically the contact angle, resulted in the observation of varied droplet patterns on the surface of gallery. Surface wettability directly influences oil distribution and adhesion on the piston surface, consequently impacting the piston’s cooling effectiveness. Optimizing the wettability of the oil cavity is expected to improve the cooling efficiency of the piston, contributing to an overall performance improvement. The numerical study revealed that a surface with a certain degree of hydrophilicity facilitates uniform droplet distribution on the surface of the gallery, forming a film-like oil droplet. Such a film of oil droplets effectively enhances heat transfer efficiency, with a well-wetted surface promoting effective contact between the oil and piston surface for more efficient heat transfer. Conversely, a highly hydrophobic surface leads to droplet self-aggregation in the gallery, hindering effective heat dissipation from the piston. Poor wettability prevents uniform oil adhesion to the piston surface, resulting in decreased heat transfer efficiency. To summarize, the wettability of the piston gallery significantly influences heat transfer performance. Optimizing surface wettability enhances piston cooling, thereby improving overall internal combustion engine performance.","PeriodicalId":54568,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part D-Journal of Automobile Engineering","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141786060","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
In this paper, an energy computation method is proposed based on the longitudinal-vertical coupling tracked vehicle dynamic model to quantificationally study the energy generation and dissipation for tracked vehicles under off-road conditions. When the tracked vehicle drives on uneven road, the suspension damping components and the additional driving resistance caused by ground roughness consumes part of the driving power. The energy consumption distributions of the tracked vehicle under different speeds, different road conditions and different driving conditions are investigated and compared. The results indicate that a larger road roughness coefficient, a higher travelling speed and a greater driving force will make the proportions of energy consumed by the suspension dampers and the additional driving resistance to the total energy consumption larger. The influence of road conditions on the energy consumption distribution of the tracked vehicle takes precedence over the tracked vehicle speed and the effect of the driving force is internally due to speed changes.
{"title":"Quantitative research on the tracked vehicle energy consumption characteristics based on the longitudinal-vertical coupling dynamics","authors":"Zhiqiang Guo, Chunwang Liu, Hongxiu Zhu, Junlin Luo, Wei Wu","doi":"10.1177/09544070241264874","DOIUrl":"https://doi.org/10.1177/09544070241264874","url":null,"abstract":"In this paper, an energy computation method is proposed based on the longitudinal-vertical coupling tracked vehicle dynamic model to quantificationally study the energy generation and dissipation for tracked vehicles under off-road conditions. When the tracked vehicle drives on uneven road, the suspension damping components and the additional driving resistance caused by ground roughness consumes part of the driving power. The energy consumption distributions of the tracked vehicle under different speeds, different road conditions and different driving conditions are investigated and compared. The results indicate that a larger road roughness coefficient, a higher travelling speed and a greater driving force will make the proportions of energy consumed by the suspension dampers and the additional driving resistance to the total energy consumption larger. The influence of road conditions on the energy consumption distribution of the tracked vehicle takes precedence over the tracked vehicle speed and the effect of the driving force is internally due to speed changes.","PeriodicalId":54568,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part D-Journal of Automobile Engineering","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784243","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-25DOI: 10.1177/09544070241262354
Nan Li, Yan Shi
Recent research has focused on active suspension systems because of their real-time ability to adapt to a variety of road surfaces, external perturbations, and potential to control the smoothness of vehicles. Since the parameters of conventional PID controllers used for active suspension control have limitations due to their inability to adapt to external changes, the fuzzy PID controllers are developed to overcome such limitations. However, fuzzy control have certain disadvantages related to the manual definition of fuzzy rules and variables. In this paper, a first step in improving the robustness of the PID control is to use the endocrine framework, which is considered to be highly nonlinear and complex in the vehicle suspension system. A deep reinforcement learning algorithm is then used to train the intelligence to provide an efficient strategy for adaptive gain adjustment for the endocrine PID, which requires no prior knowledge of active suspension control. The dynamics of the whole vehicle are modeled using ADAMS to analyze the dynamic characteristics of the vehicle at different speeds and road surfaces. The results show that the active suspension based on deep reinforcement learning controlling reduces vertical acceleration of the body more effectively and improves ride comfort more efficiently without sacrificing dynamic suspension deflection or dynamic tire load as compared with passive suspension or fuzzy PID suspensions. Further, the controller performs well under conditions such as changing road grades and vehicle speeds, indicating a good generalization.
{"title":"Adaptive endocrine PID control for active suspension based on reinforcement learning","authors":"Nan Li, Yan Shi","doi":"10.1177/09544070241262354","DOIUrl":"https://doi.org/10.1177/09544070241262354","url":null,"abstract":"Recent research has focused on active suspension systems because of their real-time ability to adapt to a variety of road surfaces, external perturbations, and potential to control the smoothness of vehicles. Since the parameters of conventional PID controllers used for active suspension control have limitations due to their inability to adapt to external changes, the fuzzy PID controllers are developed to overcome such limitations. However, fuzzy control have certain disadvantages related to the manual definition of fuzzy rules and variables. In this paper, a first step in improving the robustness of the PID control is to use the endocrine framework, which is considered to be highly nonlinear and complex in the vehicle suspension system. A deep reinforcement learning algorithm is then used to train the intelligence to provide an efficient strategy for adaptive gain adjustment for the endocrine PID, which requires no prior knowledge of active suspension control. The dynamics of the whole vehicle are modeled using ADAMS to analyze the dynamic characteristics of the vehicle at different speeds and road surfaces. The results show that the active suspension based on deep reinforcement learning controlling reduces vertical acceleration of the body more effectively and improves ride comfort more efficiently without sacrificing dynamic suspension deflection or dynamic tire load as compared with passive suspension or fuzzy PID suspensions. Further, the controller performs well under conditions such as changing road grades and vehicle speeds, indicating a good generalization.","PeriodicalId":54568,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part D-Journal of Automobile Engineering","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784398","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-25DOI: 10.1177/09544070241265395
Jinhai Zhao, Xiuheng Wu, Zhenghe Song, Liang Sun, Xiangyu Wang
Existing stability analyzes for the tractor semi-trailer cannot fully explain the instability phenomenon during combined steering and braking conditions, under which the tire lateral forces are affected by the longitudinal tire forces due to adhesive force ellipse. In response to the problem, this article obtains the coupled bifurcation and the stability area of the tractor semi-trailer under different deceleration and steering angles. First, the 8 degrees of freedom (8 DOF) tractor semi-trailer nonlinear dynamical model considering the nonlinear tire characteristics is built. The constrained continuation method is used, and the inertial force caused by braking is equivalent to two external forces and added to the tractor semi-trailer model. Thus, the tractor semi-trailer system can be seen as being in an equivalent equilibrium state. Next, the equilibrium points under varying steering angles and different decelerations are solved by a hybrid method combining the Runge-Kutta method with the gradient descent method. The bifurcation diagrams denote the changes in the equilibrium brought by different conditions and reveal the influence of different decelerations on the stable steering angle range. Further, the stable regions under different conditions are illustrated to give an understanding of the effect of the braking operations on the stability of the tractor semi-trailer. Compared with the existing literature, it can be proved that in addition to the fixed parameters such as road adhesion coefficient, the deceleration under braking conditions will also have an impact on the stability regions of the tractor semi-trailer. The stable boundary of the tractor semi-trailer under combined braking and steering conditions can be obtained by off-line calculation, and the results can serve on the theoretical considerations on the tractor semi-trailer braking stability control.
{"title":"Research on coupled bifurcation and stability of tractor semi-trailer under combined braking and steering conditions","authors":"Jinhai Zhao, Xiuheng Wu, Zhenghe Song, Liang Sun, Xiangyu Wang","doi":"10.1177/09544070241265395","DOIUrl":"https://doi.org/10.1177/09544070241265395","url":null,"abstract":"Existing stability analyzes for the tractor semi-trailer cannot fully explain the instability phenomenon during combined steering and braking conditions, under which the tire lateral forces are affected by the longitudinal tire forces due to adhesive force ellipse. In response to the problem, this article obtains the coupled bifurcation and the stability area of the tractor semi-trailer under different deceleration and steering angles. First, the 8 degrees of freedom (8 DOF) tractor semi-trailer nonlinear dynamical model considering the nonlinear tire characteristics is built. The constrained continuation method is used, and the inertial force caused by braking is equivalent to two external forces and added to the tractor semi-trailer model. Thus, the tractor semi-trailer system can be seen as being in an equivalent equilibrium state. Next, the equilibrium points under varying steering angles and different decelerations are solved by a hybrid method combining the Runge-Kutta method with the gradient descent method. The bifurcation diagrams denote the changes in the equilibrium brought by different conditions and reveal the influence of different decelerations on the stable steering angle range. Further, the stable regions under different conditions are illustrated to give an understanding of the effect of the braking operations on the stability of the tractor semi-trailer. Compared with the existing literature, it can be proved that in addition to the fixed parameters such as road adhesion coefficient, the deceleration under braking conditions will also have an impact on the stability regions of the tractor semi-trailer. The stable boundary of the tractor semi-trailer under combined braking and steering conditions can be obtained by off-line calculation, and the results can serve on the theoretical considerations on the tractor semi-trailer braking stability control.","PeriodicalId":54568,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part D-Journal of Automobile Engineering","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784399","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-25DOI: 10.1177/09544070241265152
Yunshi Wu, Donghai Su
In order to further improve the stability and comfort of automobile active suspension, a BP neural network controller based on Q-learning algorithm optimization (QBP-PID) is proposed. QBP-PID uses BP neural network to adjust the PID gain, introduces the optimal strategy of Q-learning to correct the weight momentum factor, and optimizes the key weights in the neural network, so that the controller has better learning ability and online correction ability. A quarter suspension simulation model with random road excitation as the system input is established in Simulink software. The root mean square of body acceleration and tire dynamic displacement are used as the evaluation indexes of active suspension performance. The simulation results show that compared with the traditional passive suspension, PID control suspension and BP-PID control suspension, the active suspension using QBP-PID control algorithm can significantly improve the driving stability and comfort of the vehicle.
为了进一步提高汽车主动悬架的稳定性和舒适性，提出了一种基于 Q-learning 算法优化的 BP 神经网络控制器（QBP-PID）。QBP-PID 利用 BP 神经网络调节 PID 增益，引入 Q-learning 的最优策略修正权重动量因子，优化神经网络中的关键权重，使控制器具有更好的学习能力和在线修正能力。在 Simulink 软件中建立了以随机路面激励为系统输入的四分之一悬架仿真模型。以车身加速度均方根和轮胎动态位移作为主动悬架性能的评价指标。仿真结果表明，与传统的被动悬架、PID 控制悬架和 BP-PID 控制悬架相比，采用 QBP-PID 控制算法的主动悬架能显著提高车辆的行驶稳定性和舒适性。
{"title":"Simulation analysis of quarter car active suspension control based on QBP-PID","authors":"Yunshi Wu, Donghai Su","doi":"10.1177/09544070241265152","DOIUrl":"https://doi.org/10.1177/09544070241265152","url":null,"abstract":"In order to further improve the stability and comfort of automobile active suspension, a BP neural network controller based on Q-learning algorithm optimization (QBP-PID) is proposed. QBP-PID uses BP neural network to adjust the PID gain, introduces the optimal strategy of Q-learning to correct the weight momentum factor, and optimizes the key weights in the neural network, so that the controller has better learning ability and online correction ability. A quarter suspension simulation model with random road excitation as the system input is established in Simulink software. The root mean square of body acceleration and tire dynamic displacement are used as the evaluation indexes of active suspension performance. The simulation results show that compared with the traditional passive suspension, PID control suspension and BP-PID control suspension, the active suspension using QBP-PID control algorithm can significantly improve the driving stability and comfort of the vehicle.","PeriodicalId":54568,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part D-Journal of Automobile Engineering","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-25","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784400","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.1177/09544070241264087
Zhaojun Zhu, Ziming Yang, Yikai Li, Chenghan Sun
Compared with the traditional in-cylinder direct-injection spark ignition engine, the side-injection and side-spark-ignition characteristics of the two-stroke opposed-piston engine increase the ignition kernel offset and flame propagation distance. Increasing the flame propagation speed can to some extent solve the drawbacks caused by the non-central arrangement of spark plugs. The combustion chamber structure plays a crucial role in gas flow, fuel-charge mixing, and combustion characteristics. Therefore, three pistons were designed and comparatively analyzed in this study. The results show that: The pancake piston is beneficial to maintaining the intake swirl strength due to its simple and smooth spherical arc structure. The swirl strength of the pit and pit-guided piston decreases obviously, and the tumble strength can be maintained well. Compared to pancake and pit-guided pistons, the average TKE for the pit piston increased by approximately 25%, with a more concentrated distribution at the spark timing. The pancake piston exhibits the best scavenging performance, reducing the residual exhaust gas ratio by 2.1% and fresh air loss by 3.3% to the pit piston. A stable ignition core can be formed at the spark timing, but significant differences are observed in the flame propagation process for three pistons. Compared to the pit-guided piston, the pit piston has a 0.3% decrease in the indicated thermal efficiency, but a 13.1% decrease in combustion duration, which reduces knock tendency.
{"title":"Computational analysis of piston shape effects on in-cylinder gas flow, fuel-charge mixing, and combustion characteristics in a two-stroke rod-less spark ignition opposed-pistons engine","authors":"Zhaojun Zhu, Ziming Yang, Yikai Li, Chenghan Sun","doi":"10.1177/09544070241264087","DOIUrl":"https://doi.org/10.1177/09544070241264087","url":null,"abstract":"Compared with the traditional in-cylinder direct-injection spark ignition engine, the side-injection and side-spark-ignition characteristics of the two-stroke opposed-piston engine increase the ignition kernel offset and flame propagation distance. Increasing the flame propagation speed can to some extent solve the drawbacks caused by the non-central arrangement of spark plugs. The combustion chamber structure plays a crucial role in gas flow, fuel-charge mixing, and combustion characteristics. Therefore, three pistons were designed and comparatively analyzed in this study. The results show that: The pancake piston is beneficial to maintaining the intake swirl strength due to its simple and smooth spherical arc structure. The swirl strength of the pit and pit-guided piston decreases obviously, and the tumble strength can be maintained well. Compared to pancake and pit-guided pistons, the average TKE for the pit piston increased by approximately 25%, with a more concentrated distribution at the spark timing. The pancake piston exhibits the best scavenging performance, reducing the residual exhaust gas ratio by 2.1% and fresh air loss by 3.3% to the pit piston. A stable ignition core can be formed at the spark timing, but significant differences are observed in the flame propagation process for three pistons. Compared to the pit-guided piston, the pit piston has a 0.3% decrease in the indicated thermal efficiency, but a 13.1% decrease in combustion duration, which reduces knock tendency.","PeriodicalId":54568,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part D-Journal of Automobile Engineering","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141786239","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2024-07-24DOI: 10.1177/09544070241263888
Jinyi Liu, Fushan Yan, He Dong, Lirong Fu, Ying Zhao
In China, the village roads are characterized by numerous intersections and significant differences in road widths, creating a complex maze-like terrain. This undoubtedly increases the difficulty of path planning for autonomous vehicles. This study proposes an improved bidirectional RRT* algorithm that utilizes the advantages of the rapid random search of the RRT* algorithm. It introduces virtual points to address the irregularity of road networks and creates enveloping circles at expanding nodes to enhance path reachability, thus obtaining the optimal global planning path. To enhance path tracking comfort, a fifth-order B-spline curve is utilized to smooth the global path, and local path planning is performed using Quadratic Programming (QP). The proposed combined global and local path planning method was evaluated through Co-simulation experiments basing on the Matlab/CarSim/PreScan platform. Simulation results demonstrate that the enhanced RRT* algorithm outperforms the traditional RRT* algorithm in the same scenario. Specifically, the improved algorithm reduces the running time by 29.56%, increases node utilization by approximately 15.33%, and decreases the planned path length by 2.8%. Additionally, the vehicle’s final lateral tracking error was controlled within 0–0.04 m, and the longitudinal tracking error was controlled within 0–0.1 m, fully demonstrating the vehicle’s excellent path-tracking performance. The study’s innovative ideas will offer methodological support for researching path planning for autonomous vehicles in specific scenarios.
{"title":"A global and local integrated dynamic path planning algorithm for village roads region","authors":"Jinyi Liu, Fushan Yan, He Dong, Lirong Fu, Ying Zhao","doi":"10.1177/09544070241263888","DOIUrl":"https://doi.org/10.1177/09544070241263888","url":null,"abstract":"In China, the village roads are characterized by numerous intersections and significant differences in road widths, creating a complex maze-like terrain. This undoubtedly increases the difficulty of path planning for autonomous vehicles. This study proposes an improved bidirectional RRT* algorithm that utilizes the advantages of the rapid random search of the RRT* algorithm. It introduces virtual points to address the irregularity of road networks and creates enveloping circles at expanding nodes to enhance path reachability, thus obtaining the optimal global planning path. To enhance path tracking comfort, a fifth-order B-spline curve is utilized to smooth the global path, and local path planning is performed using Quadratic Programming (QP). The proposed combined global and local path planning method was evaluated through Co-simulation experiments basing on the Matlab/CarSim/PreScan platform. Simulation results demonstrate that the enhanced RRT* algorithm outperforms the traditional RRT* algorithm in the same scenario. Specifically, the improved algorithm reduces the running time by 29.56%, increases node utilization by approximately 15.33%, and decreases the planned path length by 2.8%. Additionally, the vehicle’s final lateral tracking error was controlled within 0–0.04 m, and the longitudinal tracking error was controlled within 0–0.1 m, fully demonstrating the vehicle’s excellent path-tracking performance. The study’s innovative ideas will offer methodological support for researching path planning for autonomous vehicles in specific scenarios.","PeriodicalId":54568,"journal":{"name":"Proceedings of the Institution of Mechanical Engineers Part D-Journal of Automobile Engineering","volume":null,"pages":null},"PeriodicalIF":1.7,"publicationDate":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784402","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":4,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
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