Pub Date : 2024-07-24DOI: 10.1177/09544070241264881
Hui Liu, Congshuai Guo, Lijin Han, Shida Nie
Compared with the structured environment, off-road environment has complex and ever-changing road conditions. This paper is focused on the vehicle adaptive cruise task for vehicles driving on complex off-road terrain. Traditional ACC strategies do not take the complex road conditions into consideration, thus easily make the relative distance between vehicles unreasonable. To solve this problem, an off-road adaptive cruise control (OACC) strategy is proposed for off-roads with changeable pavement and slope. Firstly, the influence of road conditions and vehicle relative motion states on safe distance between vehicles have analyzed with the aim of developing a more reasonable space strategy for off-road conditions. Then, based on the analysis results, an improved safe distance model (ISDM) is proposed which take the influence factors into account comprehensively. The concept of road impact factor is proposed to prevent model degradation and effectively balance the influence of single road conditions and comprehensive factors on safe distance. Besides, target to improve the adaptability of ACC, a novel state space model has developed which can handle not only the change of vehicle motion states but also road conditions. In addition, the MPC-based OACC for off-road environment is proposed, which can enable the vehicle to better adapt to relative motion states and road conditions based on the novel state space model. Finally, the performance of OACC is verified by co-simulation in MATLAB/Simulink and Carsim, and a hardware-in-the-loop simulation system. Furthermore, the analysis of ISDM has conducted to illustrate the differences and similarities compared with the traditional safe distance models and to verify the effectiveness of ISDM. Simulation results show that the OACC and ISDM proposed in this paper have great performance in different off-road working conditions.
{"title":"Vehicle adaptive cruise control strategy based on improved safe distance model for off-roads with changeable pavement and slope","authors":"Hui Liu, Congshuai Guo, Lijin Han, Shida Nie","doi":"10.1177/09544070241264881","DOIUrl":"https://doi.org/10.1177/09544070241264881","url":null,"abstract":"Compared with the structured environment, off-road environment has complex and ever-changing road conditions. This paper is focused on the vehicle adaptive cruise task for vehicles driving on complex off-road terrain. Traditional ACC strategies do not take the complex road conditions into consideration, thus easily make the relative distance between vehicles unreasonable. To solve this problem, an off-road adaptive cruise control (OACC) strategy is proposed for off-roads with changeable pavement and slope. Firstly, the influence of road conditions and vehicle relative motion states on safe distance between vehicles have analyzed with the aim of developing a more reasonable space strategy for off-road conditions. Then, based on the analysis results, an improved safe distance model (ISDM) is proposed which take the influence factors into account comprehensively. The concept of road impact factor is proposed to prevent model degradation and effectively balance the influence of single road conditions and comprehensive factors on safe distance. Besides, target to improve the adaptability of ACC, a novel state space model has developed which can handle not only the change of vehicle motion states but also road conditions. In addition, the MPC-based OACC for off-road environment is proposed, which can enable the vehicle to better adapt to relative motion states and road conditions based on the novel state space model. Finally, the performance of OACC is verified by co-simulation in MATLAB/Simulink and Carsim, and a hardware-in-the-loop simulation system. Furthermore, the analysis of ISDM has conducted to illustrate the differences and similarities compared with the traditional safe distance models and to verify the effectiveness of ISDM. Simulation results show that the OACC and ISDM proposed in this paper have great performance in different off-road 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":"2024-07-24","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784401","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: 10.1177/09544070241264366
Zhigen Nie, Yi Zhou, Yufeng Lian
Trajectory planning and tracking of lane change are critical technologies for autonomous buses. Characteristics of the buses susceptible to stability problems resulting from the high height, large passenger capacity and long lengths, coupling the dynamic traffic with the dynamic changes in the states of adjacent vehicles and road adhesion coefficient, put forward great challenges in lane change for autonomous buses (ABs). To cope with the foregoing challenges, a framework is proposed to achieve the trajectory planning and tracking of dynamic lane change for ABs. For trajectory planning approach, the trajectory planning and replanning is optimized in the safe range of longitudinal length of the lane-changing trajectory to obtain the real-time reference trajectory, combining consideration of vehicle yaw, roll stability and lane-changing efficiency. The minimum longitudinal length of lane-changing trajectory determined by the yaw stability and roll stability of ABs, combined with the maximum length formed by the adjacent vehicles with dynamic states, form the real-time safe range for lane-changing trajectory planning. For trajectory tracking approach, a tracking approach using model predictive control based on multipoint preview is proposed to achieve the real-time planned trajectory tracking considering buses stability. The effectiveness of the proposed strategy is evaluated by simulating an experimentally validated Trucksim model in different dynamic traffic scenarios to demonstrate the capability of the strategy in trajectory planning and tracking, and guaranteeing vehicle stability for dynamic lane change of ABs.
轨迹规划和变道跟踪是自动驾驶巴士的关键技术。客车高度高、载客量大、长度长等特点容易导致稳定性问题，再加上动态交通与相邻车辆状态和道路附着系数的动态变化，给自动驾驶客车（ABs）的变道带来了巨大挑战。为应对上述挑战，本文提出了实现自动驾驶巴士动态变道轨迹规划和跟踪的框架。在轨迹规划方法中，轨迹规划和重新规划在变道轨迹纵向长度的安全范围内进行优化，以获得实时参考轨迹，同时兼顾车辆偏航、侧滚稳定性和变道效率。由 AB 车辆的偏航稳定性和侧滚稳定性确定的变道轨迹纵向长度最小值，结合相邻车辆动态状态形成的最大长度，构成变道轨迹规划的实时安全范围。在轨迹跟踪方法方面，提出了一种基于多点预览的模型预测控制跟踪方法，以实现考虑总线稳定性的实时规划轨迹跟踪。通过在不同的动态交通场景中模拟经过实验验证的 Trucksim 模型，评估了所提策略的有效性，从而证明了该策略在轨迹规划和跟踪方面的能力，并保证了 AB 动态变道时的车辆稳定性。
{"title":"Trajectory planning and tracking of dynamic lane change for autonomous buses considering vehicle stability in dynamic traffic scenarios","authors":"Zhigen Nie, Yi Zhou, Yufeng Lian","doi":"10.1177/09544070241264366","DOIUrl":"https://doi.org/10.1177/09544070241264366","url":null,"abstract":"Trajectory planning and tracking of lane change are critical technologies for autonomous buses. Characteristics of the buses susceptible to stability problems resulting from the high height, large passenger capacity and long lengths, coupling the dynamic traffic with the dynamic changes in the states of adjacent vehicles and road adhesion coefficient, put forward great challenges in lane change for autonomous buses (ABs). To cope with the foregoing challenges, a framework is proposed to achieve the trajectory planning and tracking of dynamic lane change for ABs. For trajectory planning approach, the trajectory planning and replanning is optimized in the safe range of longitudinal length of the lane-changing trajectory to obtain the real-time reference trajectory, combining consideration of vehicle yaw, roll stability and lane-changing efficiency. The minimum longitudinal length of lane-changing trajectory determined by the yaw stability and roll stability of ABs, combined with the maximum length formed by the adjacent vehicles with dynamic states, form the real-time safe range for lane-changing trajectory planning. For trajectory tracking approach, a tracking approach using model predictive control based on multipoint preview is proposed to achieve the real-time planned trajectory tracking considering buses stability. The effectiveness of the proposed strategy is evaluated by simulating an experimentally validated Trucksim model in different dynamic traffic scenarios to demonstrate the capability of the strategy in trajectory planning and tracking, and guaranteeing vehicle stability for dynamic lane change of ABs.","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":"141786249","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: 10.1177/09544070241265392
Hao Zhang, Chao Wei, Yuanhao He
Multi-vehicle formation can perform various special tasks in unstructured environment. How to take into account the safety of vehicles in avoiding obstacles and the ability to maintain formation has a certain research value. In this paper, the four-circle model of vehicle is established first, and the circle radius is adjusted according to the state of vehicle, so as to describe the safety boundary of vehicle. The improved RRT algorithm is used for the whole route planning, and the discrete path points are used as vehicle guidance. Then the artificial potential field is constructed, and the formation coordination potential field is proposed, so that the vehicles can cooperate with other vehicles to keep the preset formation as far as possible when avoiding obstacles. Then the control quantity of the vehicle is calculated according to the force condition of the vehicle in the potential field by the double exponential sliding mode control method. Finally, the effectiveness of the method is verified by the simulation experiments of triangle formation and circular formation under different working conditions, and the formation error is reduced by about 20%.
{"title":"Research on multi-vehicle formation control based on improved artificial potential field method","authors":"Hao Zhang, Chao Wei, Yuanhao He","doi":"10.1177/09544070241265392","DOIUrl":"https://doi.org/10.1177/09544070241265392","url":null,"abstract":"Multi-vehicle formation can perform various special tasks in unstructured environment. How to take into account the safety of vehicles in avoiding obstacles and the ability to maintain formation has a certain research value. In this paper, the four-circle model of vehicle is established first, and the circle radius is adjusted according to the state of vehicle, so as to describe the safety boundary of vehicle. The improved RRT algorithm is used for the whole route planning, and the discrete path points are used as vehicle guidance. Then the artificial potential field is constructed, and the formation coordination potential field is proposed, so that the vehicles can cooperate with other vehicles to keep the preset formation as far as possible when avoiding obstacles. Then the control quantity of the vehicle is calculated according to the force condition of the vehicle in the potential field by the double exponential sliding mode control method. Finally, the effectiveness of the method is verified by the simulation experiments of triangle formation and circular formation under different working conditions, and the formation error is reduced by about 20%.","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":"141786061","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: 10.1177/09544070241263881
Carmen Gheorghe, Răzvan Gabriel Boboc, Florin Gîrbacia, Adrian Şoica
Road traffic surveillance using unmanned aerial vehicles is a practice that can be found especially in the field of intelligent vehicle management, which is still in the early stages of research and application. This paper presents three methods of analyzing traffic data. One method is a conventional one, based on Doppler radar detection and the other two methods analyze images captured by unmanned aerial vehicles, being based on deep learning techniques. After acquiring the images, they went through a complex processing process to eliminate noise and improve the clarity of the image, then the identification of the vehicles was done by recognizing moving objects and highlighting them either through a bounding box or through labelling. The quality of images obtained from unmanned aerial vehicles is similar to the quality of images obtained from fixed surveillance cameras. The comparative analysis of the results obtained through image processing, together with those obtained through a conventional method of traffic analysis, the Doppler radar, highlighted the fact that video detection used in intelligent vehicle management is a method that both researchers and local authorities can rely on the performance of traffic studies or the analysis of traffic incidents and accidents.
{"title":"Above the roads: Unleashing unmanned aerial vehicles and image processing for traffic analysis","authors":"Carmen Gheorghe, Răzvan Gabriel Boboc, Florin Gîrbacia, Adrian Şoica","doi":"10.1177/09544070241263881","DOIUrl":"https://doi.org/10.1177/09544070241263881","url":null,"abstract":"Road traffic surveillance using unmanned aerial vehicles is a practice that can be found especially in the field of intelligent vehicle management, which is still in the early stages of research and application. This paper presents three methods of analyzing traffic data. One method is a conventional one, based on Doppler radar detection and the other two methods analyze images captured by unmanned aerial vehicles, being based on deep learning techniques. After acquiring the images, they went through a complex processing process to eliminate noise and improve the clarity of the image, then the identification of the vehicles was done by recognizing moving objects and highlighting them either through a bounding box or through labelling. The quality of images obtained from unmanned aerial vehicles is similar to the quality of images obtained from fixed surveillance cameras. The comparative analysis of the results obtained through image processing, together with those obtained through a conventional method of traffic analysis, the Doppler radar, highlighted the fact that video detection used in intelligent vehicle management is a method that both researchers and local authorities can rely on the performance of traffic studies or the analysis of traffic incidents and accidents.","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":"141786062","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 : 2024-07-23DOI: 10.1177/09544070241261113
Chaoning Chen, Jiancheng Zhang, Hongyu Zheng
Steer-by-wire (SBW) systems with steering actuator motors rotating the front wheels allow more flexibility for handling stability control; however, determining the desired steering angle and accurately tracking the desired steering angle are still key challenges. Therefore, a modified handling stability control strategy for handling stability is proposed in this paper. Firstly, based on the normal function, a unified variable steering ratio (UniVSR) model that varies with vehicle speed and steering wheel angle is developed. Then, the UniVSR model parameters are optimized by particle swarm optimization (PSO) algorithm in speed segments to improve the steering sensitivity at low speeds and the stability at medium and high speeds. Next, the active front steering (AFS) controller that considers the intervention timing and intervention threshold is proposed to improve the stability of the SBW vehicle under the driving conditions of low-adhesion road, split-μ road, and lateral wind interference. Lastly, the linear active disturbance rejection control (LADRC) based angle tracking control algorithm is presented to guarantee the desired angle tracking accuracy of the steering actuator motor under both internal parameter and external torque perturbations. The simulations validate the effectiveness of the proposed UniVSR model and AFS controller in improving handling stability.
{"title":"A modified handling stability control strategy for steer-by-wire vehicles based on variable steering ratio and active front steering control","authors":"Chaoning Chen, Jiancheng Zhang, Hongyu Zheng","doi":"10.1177/09544070241261113","DOIUrl":"https://doi.org/10.1177/09544070241261113","url":null,"abstract":"Steer-by-wire (SBW) systems with steering actuator motors rotating the front wheels allow more flexibility for handling stability control; however, determining the desired steering angle and accurately tracking the desired steering angle are still key challenges. Therefore, a modified handling stability control strategy for handling stability is proposed in this paper. Firstly, based on the normal function, a unified variable steering ratio (UniVSR) model that varies with vehicle speed and steering wheel angle is developed. Then, the UniVSR model parameters are optimized by particle swarm optimization (PSO) algorithm in speed segments to improve the steering sensitivity at low speeds and the stability at medium and high speeds. Next, the active front steering (AFS) controller that considers the intervention timing and intervention threshold is proposed to improve the stability of the SBW vehicle under the driving conditions of low-adhesion road, split-μ road, and lateral wind interference. Lastly, the linear active disturbance rejection control (LADRC) based angle tracking control algorithm is presented to guarantee the desired angle tracking accuracy of the steering actuator motor under both internal parameter and external torque perturbations. The simulations validate the effectiveness of the proposed UniVSR model and AFS controller in improving handling stability.","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":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141786240","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 : 2024-07-23DOI: 10.1177/09544070241259067
Binyu Zhang, Yigang Wang, Wuzhou Yu, Bin Ye, Zining Peng, Hao Zhang
Due to the various geometric shapes of cavities within car door sealing systems, the resulting cavity noise induced by wind excitation exhibits complex characteristics, leading to unclear noise mechanisms. To address this, a study was conducted to examine the acoustic properties of door sealing cavities located in the B-pillar, C-pillar, and backdoor of an SUV within a full-scale aeroacoustic wind tunnel. The main objective was to explore the relationship between cavity noise and interior noise. The results showed that peak components in the sound pressure level spectrum of the cavities significantly contribute to interior noise, particularly for cavities located close to the car’s interior. To gain further insight, the geometric characteristics of the cavities were extracted and transformed into equivalent regular cavities. These equivalent cavities were subsequently tested for their noise performance in a small-scale aeroacoustic wind tunnel, and the occurrence mechanisms were thoroughly investigated. The results demonstrated that the noise spectra of different cavities, whether they had sealing strips or leakage gaps, exhibited typical multipeak characteristics, with some cases even leading to whistling (e.g. backdoor cavity). The reason for the whistling was a resonance when the self-sustained oscillation frequencies of the cavities coincided with or approached the Helmholtz resonance frequencies or modal frequencies of the cavities. Interestingly, the self-sustained oscillation frequency and cavity modal resonance still persisted even when the two frequencies were somewhat separated, albeit with peaks of lower magnitude in the sound pressure spectrum (e.g. in the sealed cavities of the B-pillar and C-pillar).
由于汽车车门密封系统内的空腔具有不同的几何形状，因此由风激励引起的空腔噪声表现出复杂的特性，导致噪声机制不明确。为了解决这个问题，我们在全尺寸航空声学风洞中对一辆 SUV 的 B 柱、C 柱和后门的车门密封空腔的声学特性进行了研究。主要目的是探索空腔噪声与车内噪声之间的关系。结果表明，空腔声压级频谱中的峰值成分对车内噪声有很大影响，尤其是靠近汽车内部的空腔。为了进一步了解情况，我们提取了空腔的几何特征，并将其转化为等效的规则空腔。随后，在小型航空声学风洞中对这些等效空腔的噪声性能进行了测试，并对其发生机制进行了深入研究。结果表明，不同空腔的噪声频谱，无论是密封条还是泄漏间隙，都表现出典型的多峰特性，有些甚至会产生啸叫（如后门空腔）。产生啸叫的原因是当空腔的自持振荡频率与亥姆霍兹共振频率或空腔的模态频率重合或接近时产生的共振。有趣的是，即使这两个频率相隔较远，自持振荡频率和空腔模态共振仍然存在，尽管在声压频谱中的峰值较低（例如在 B 柱和 C 柱的密封空腔中）。
{"title":"Experiment research on the characteristics and mechanism of noise caused by a car door sealing cavity at wind excitation","authors":"Binyu Zhang, Yigang Wang, Wuzhou Yu, Bin Ye, Zining Peng, Hao Zhang","doi":"10.1177/09544070241259067","DOIUrl":"https://doi.org/10.1177/09544070241259067","url":null,"abstract":"Due to the various geometric shapes of cavities within car door sealing systems, the resulting cavity noise induced by wind excitation exhibits complex characteristics, leading to unclear noise mechanisms. To address this, a study was conducted to examine the acoustic properties of door sealing cavities located in the B-pillar, C-pillar, and backdoor of an SUV within a full-scale aeroacoustic wind tunnel. The main objective was to explore the relationship between cavity noise and interior noise. The results showed that peak components in the sound pressure level spectrum of the cavities significantly contribute to interior noise, particularly for cavities located close to the car’s interior. To gain further insight, the geometric characteristics of the cavities were extracted and transformed into equivalent regular cavities. These equivalent cavities were subsequently tested for their noise performance in a small-scale aeroacoustic wind tunnel, and the occurrence mechanisms were thoroughly investigated. The results demonstrated that the noise spectra of different cavities, whether they had sealing strips or leakage gaps, exhibited typical multipeak characteristics, with some cases even leading to whistling (e.g. backdoor cavity). The reason for the whistling was a resonance when the self-sustained oscillation frequencies of the cavities coincided with or approached the Helmholtz resonance frequencies or modal frequencies of the cavities. Interestingly, the self-sustained oscillation frequency and cavity modal resonance still persisted even when the two frequencies were somewhat separated, albeit with peaks of lower magnitude in the sound pressure spectrum (e.g. in the sealed cavities of the B-pillar and C-pillar).","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":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784403","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 : 2024-07-23DOI: 10.1177/09544070241260901
Peng Zhuokai, Chen Weiqiang, Liu Jing, Zhu Linpei, Wei Dan
In this paper, the fatigue characteristics of the electric drive system in driving load cases and random vibration load cases are analyzed numerically and experimentally. The fatigue life of the driving system under these two load cases is analyzed by using the time domain method and frequency domain method respectively. The results show that the damage of rotating parts (gear and bearing) mainly occurs in driving load cases, and the damage of gear and bearing in the driving load cases is 71.78% and 43.46% respectively. Fixed components (housing and suspension support) have certain damage in driving load cases and random vibration load cases, and the damage is greater in driving load cases. The damage of housing and suspension support in driving load cases is 10.6% and 0.167% respectively; the damage under random vibration load cases is 1.32 × 10−11 and 3.12 × 10−11 respectively. Based on the above conclusions, it is suggested that the driving load case tests for electric driving system are necessary, but it is not necessary to do random vibration tests only for electric driving system, or the number of random vibration tests can be reduced. This not only ensures the reliability of the components, but also helps to reduce the test cost.
{"title":"Fatigue life sensitivity research for electric driving system in driving load cases and random vibration load cases","authors":"Peng Zhuokai, Chen Weiqiang, Liu Jing, Zhu Linpei, Wei Dan","doi":"10.1177/09544070241260901","DOIUrl":"https://doi.org/10.1177/09544070241260901","url":null,"abstract":"In this paper, the fatigue characteristics of the electric drive system in driving load cases and random vibration load cases are analyzed numerically and experimentally. The fatigue life of the driving system under these two load cases is analyzed by using the time domain method and frequency domain method respectively. The results show that the damage of rotating parts (gear and bearing) mainly occurs in driving load cases, and the damage of gear and bearing in the driving load cases is 71.78% and 43.46% respectively. Fixed components (housing and suspension support) have certain damage in driving load cases and random vibration load cases, and the damage is greater in driving load cases. The damage of housing and suspension support in driving load cases is 10.6% and 0.167% respectively; the damage under random vibration load cases is 1.32 × 10<jats:sup>−11</jats:sup> and 3.12 × 10<jats:sup>−11</jats:sup> respectively. Based on the above conclusions, it is suggested that the driving load case tests for electric driving system are necessary, but it is not necessary to do random vibration tests only for electric driving system, or the number of random vibration tests can be reduced. This not only ensures the reliability of the components, but also helps to reduce the test cost.","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":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784418","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 : 2024-07-23DOI: 10.1177/09544070241256714
Zechuan Cui, Jiangping Tian, Xiaolei Zhang, Mingyuan Ye, Kaile Wei, Peng Wang, Song Shi
The combustion characteristics of lean methane/air mixtures ignited by single and multiple diesel sprays were investigated using an optical RCEM test bench. The experimental approach included flame natural luminescence photography, pressure data acquisition, and heat release analysis. The results revealed that the relationships of ignition delay and orifice diameter varied under single diesel and dual fuel combustion mode. Under dual fuel mode, increasing the orifice diameter of the single-orifice nozzle resulted in a reduction in ignition delay, an acceleration in flame propagation, and an increase in the heat release rate. Increasing the number of orifices multiplied the flame regions, expanded the flame propagation pathways, and enhanced the promoting effect between the flames, resulting in faster flame propagation and increased heat release. The orifice axis angle significantly affected the ignition position and flame propagation direction. An appropriate axis angle would shorten the flame propagation distance, optimize the flame propagation direction and mitigate the impediment effect between flames.
{"title":"Optical study on the single and multiple regions of flame propagation and combustion characteristics of methane/air mixture ignited by pilot diesel","authors":"Zechuan Cui, Jiangping Tian, Xiaolei Zhang, Mingyuan Ye, Kaile Wei, Peng Wang, Song Shi","doi":"10.1177/09544070241256714","DOIUrl":"https://doi.org/10.1177/09544070241256714","url":null,"abstract":"The combustion characteristics of lean methane/air mixtures ignited by single and multiple diesel sprays were investigated using an optical RCEM test bench. The experimental approach included flame natural luminescence photography, pressure data acquisition, and heat release analysis. The results revealed that the relationships of ignition delay and orifice diameter varied under single diesel and dual fuel combustion mode. Under dual fuel mode, increasing the orifice diameter of the single-orifice nozzle resulted in a reduction in ignition delay, an acceleration in flame propagation, and an increase in the heat release rate. Increasing the number of orifices multiplied the flame regions, expanded the flame propagation pathways, and enhanced the promoting effect between the flames, resulting in faster flame propagation and increased heat release. The orifice axis angle significantly affected the ignition position and flame propagation direction. An appropriate axis angle would shorten the flame propagation distance, optimize the flame propagation direction and mitigate the impediment effect between flames.","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":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784415","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}
This paper proposes an adaptive backstepping sliding mode control strategy for addressing nonlinear issues in the semi-active suspension systems, such as uncertainties and external disturbances. Firstly, a hyperbolic tangent model is chosen for parameters identification of the magnetorheological (MR) damper, and a model for the semi-active suspension system is established. Secondly, a control strategy is designed by combining the backstepping and sliding mode control strategies, and adaptive methods are employed to mitigate external disturbances, enhance the robustness of the controller, and estimate system uncertainties. Finally, the stability and controllability of the closed-loop system are verified using Lyapunov theory. Under the road excitations of A-Class, B-Class, and speed bump, the dynamic characteristics of the passive control, backstepping sliding mode control, and adaptive backstepping sliding mode control strategies applied to the MR semi-active suspension are analyzed. The vertical acceleration of vehicle body, suspension dynamic deflection, and tire dynamic load are selected as evaluation indexes, the results indicate that this control strategy significantly improved the ride comfort and handling stability of the vehicle.
本文提出了一种自适应反步进滑模控制策略，用于解决半主动悬架系统中的非线性问题，如不确定性和外部干扰。首先，选择双曲正切模型对磁流变（MR）减振器进行参数识别，并建立半主动悬架系统模型。其次，结合反步法和滑模控制策略设计了一种控制策略，并采用自适应方法来缓解外部干扰、增强控制器的鲁棒性以及估计系统的不确定性。最后，利用 Lyapunov 理论验证了闭环系统的稳定性和可控性。在 A 级、B 级和减速带等路面激励下，分析了应用于 MR 半主动悬架的被动控制、反步滑模控制和自适应反步滑模控制策略的动态特性。选取车身垂直加速度、悬架动态挠度和轮胎动态载荷作为评价指标，结果表明该控制策略显著提高了车辆的乘坐舒适性和操纵稳定性。
{"title":"An adaptive backstepping sliding mode control strategy for the magnetorheological semi-active suspension","authors":"Xin Xiong, Zeyu Pan, Yaming Liu, Jingjing Yue, Fei Xu","doi":"10.1177/09544070241260454","DOIUrl":"https://doi.org/10.1177/09544070241260454","url":null,"abstract":"This paper proposes an adaptive backstepping sliding mode control strategy for addressing nonlinear issues in the semi-active suspension systems, such as uncertainties and external disturbances. Firstly, a hyperbolic tangent model is chosen for parameters identification of the magnetorheological (MR) damper, and a model for the semi-active suspension system is established. Secondly, a control strategy is designed by combining the backstepping and sliding mode control strategies, and adaptive methods are employed to mitigate external disturbances, enhance the robustness of the controller, and estimate system uncertainties. Finally, the stability and controllability of the closed-loop system are verified using Lyapunov theory. Under the road excitations of A-Class, B-Class, and speed bump, the dynamic characteristics of the passive control, backstepping sliding mode control, and adaptive backstepping sliding mode control strategies applied to the MR semi-active suspension are analyzed. The vertical acceleration of vehicle body, suspension dynamic deflection, and tire dynamic load are selected as evaluation indexes, the results indicate that this control strategy significantly improved the ride comfort and handling stability 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":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141784416","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 : 2024-07-23DOI: 10.1177/09544070241260469
Xiaojian Wu, Sheng Guan, Yueyan Zhu, Tingfang Zhang, Yunxing Luo
Active Front Steering (AFS) and Differential Braking System (DBS) are commonly used execution systems for vehicle anti-rollover or handling stability control. They regulate the vehicle’s yaw moment by adjusting the lateral tire force and longitudinal tire force, respectively. However, these two systems differ in terms of control capabilities and regulatory sensitivities. In emergency conditions, it becomes crucial to allocate and coordinate the tasks for the execution systems according to their yaw moment control capability and adjustment sensitivity. This paper proposes a method for calculating the controllable region represented by the additional yaw moment. This method allows for the computation of the control capability of AFS and DBS based on the current state. Additionally, the influence of different vehicle states on the controllable regions of the two execution systems is analyzed. Building upon this analysis, the yaw moment adjustment sensitivities of AFS and DBS systems under the current state are further investigated. Finally, a task coordinated strategy between AFS and DBS is developed based on the analysis of controllable regions and sensitivities of different execution systems. Simulink simulations are conducted on yaw stability and roll stability conditions to comprehensively analyze the working process of the proposed task coordination strategy.
{"title":"Controllable region analysis of active front steering and differential braking system stability control characterized by additional yaw moment","authors":"Xiaojian Wu, Sheng Guan, Yueyan Zhu, Tingfang Zhang, Yunxing Luo","doi":"10.1177/09544070241260469","DOIUrl":"https://doi.org/10.1177/09544070241260469","url":null,"abstract":"Active Front Steering (AFS) and Differential Braking System (DBS) are commonly used execution systems for vehicle anti-rollover or handling stability control. They regulate the vehicle’s yaw moment by adjusting the lateral tire force and longitudinal tire force, respectively. However, these two systems differ in terms of control capabilities and regulatory sensitivities. In emergency conditions, it becomes crucial to allocate and coordinate the tasks for the execution systems according to their yaw moment control capability and adjustment sensitivity. This paper proposes a method for calculating the controllable region represented by the additional yaw moment. This method allows for the computation of the control capability of AFS and DBS based on the current state. Additionally, the influence of different vehicle states on the controllable regions of the two execution systems is analyzed. Building upon this analysis, the yaw moment adjustment sensitivities of AFS and DBS systems under the current state are further investigated. Finally, a task coordinated strategy between AFS and DBS is developed based on the analysis of controllable regions and sensitivities of different execution systems. Simulink simulations are conducted on yaw stability and roll stability conditions to comprehensively analyze the working process of the proposed task coordination strategy.","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":"2024-07-23","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"141786063","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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