Browse Topic: Slip

Items (772)
Wheel-corner brake failures can significantly deteriorate vehicle stability and safety, since unbalanced braking forces may introduce an undesired yaw moment. This work investigates a fault-tolerant control strategy for Active Wheel-Corner Systems, exploiting Four-Wheel Independent Steering (4WIS) to mitigate such effects and preserve vehicle stability when brake actuator malfunctions occur. Unlike many existing approaches, the proposed framework does not require explicit fault detection or quantification as a prerequisite for corrective action, eliminating potential delays and uncertainties associated with fault-diagnosis schemes. A reference model for yaw rate and sideslip angle, incorporating combined longitudinal and lateral dynamics, is proposed, and a Weighted Pseudo-Inverse Control Allocation (WPCA) scheme is employed to distribute corrective actions among the four steering angles according to each tire’s capability, compensating for yaw moment imbalances caused by degraded
Sonnino, SamuelMelzi, StefanoCaresia, PietroManzoni, AlessandroVaini, Gianluca
The lateral and longitudinal dynamics of passenger car tyres are critical to overall vehicle safety, handling, and stability. These characteristics directly influence braking, acceleration, and cornering performance. This study investigates the impact of key input parameters, namely inflation pressure, vertical load, and inclination angle, on tyre behaviour using a dual approach: Indoor testing with a Flat-Trac CT+ (FTCT+) and Outdoor evaluation using a skid trailer. Lateral dynamics are evaluated at slip angles to analyze lateral force and aligning moment characteristics. The influence of inclination angle, pressure, and load is quantified through cornering stiffness and aligning stiffness. The tests are conducted in both sweep and steady-state modes. To maintain data consistency, all tests use tyres of a single specification sourced from the same production batch. Longitudinal behaviour of a tyre is characterized by various parameters such as peak friction coefficient, sliding
Sethumadhavan, ArjunDuryodhana, DasariTomer, AvinashGhosh, PrasenjitMukhopadhyay, Rabindra
Tyre rolling resistance is a fundamental parameter in automotive engineering, directly impacting vehicle fuel efficiency and overall performance. The Rolling Resistance Coefficient (RRC) is influenced by tyre construction, material properties, and operational conditions such as inflation pressure, vehicle speed, ambient temperature, and road surface roughness. This study investigates the influence of critical parameters—including test speed, inflation pressure, temperature on the rolling resistance of tyres of various sizes. While previous research has predominantly focused on radial tyres, this paper extends the analysis to include bias-ply tyres. The findings aim to offer valuable insights for policymakers and researchers by examining the behavior of bias tyres under real-world conditions. The results will be particularly beneficial for vehicle and steering system designers, offering data-driven insights to support future tyre and vehicle development. Additionally, the study presents
Joshi, AmolBelavadi Venkataramaiah, ShamsundaraKhairatkar, Vyankatesh
The automotive industry is highly competitive, especially in terms of design and perceived quality. The use of hard plastics with a high gloss finish is driven by styling trends and the push towards zero gaps, making interfaces critical. In-cabin mood lighting is another feature being offered as a theme for interiors. Dashboard or cockpit designs often incorporate a significant amount of polycarbonate-acrylonitrile butadiene styrene (PC-ABS) and polycarbonate (PC). These materials provide strength and design flexibility but have the disadvantage of material incompatibility when used together, leading to stick-slip phenomena. Traditionally, felt tapes were used as interface isolation to solve this problem, but this increased manufacturing costs and assembly complications. The study focuses on the stick-slip phenomenon and material interface modifications. Specifically, it examines selecting the right surface finish on one side of the PC & PC-ABS interface to change adhesion and friction
Mohammed, RiyazuddinR, PrasathRahman, Shafeeq
Quieter cabins in an automobile are the new era, they provide customers with pleasurable driving experience. Squeak and Rattle are spoil sport for any OEM that aim to improvise customer driving experience. Their nonlinear nature makes it difficult to formulate design frontloading methods. The issue of seals rubbing against the body & door interface is a clear sign of seal squeak & seal chucking. Seals are applied with anti-friction coatings to avoid stick slip phenomena between EPDM and painted panel. Primary root cause for seal squeak is coating erosion. The challenge lies in determining whether the body or the closure side contributes to the seal issue. This paper presents a distinctive approach for identifying the seal squeaking noise and enriches on the new modelling methods for seal interaction with door and body interfaces using FE software. The proposed method was able to highlight the locations along the door-body interface for squeak noise. The approach for reducing the
H, RavishankarC M, MithunMichael Stephan, Navin Estac RajaMohammed, Riyazuddin
This paper proposes a DYC/ABS coordinated control strategy for cornering and braking based on driver intention. A hierarchical control structure is established, where the upper-level controller uses a vehicle dynamics model to calculate the additional yaw moment required by the DYC controller to track the desired yaw rate and sideslip angle, as well as the driver’s intended braking intensity. Taking multiple constraints into account, a quadratic programming algorithm is employed to optimize the distribution of braking forces among the four wheels. The lower-level ABS controller is designed with multiple thresholds and corresponding control phases to precisely regulate the hydraulic pressure of individual wheel cylinders. In emergency braking scenarios where ABS intervention may conflict with the upper-layer braking force allocation, a rule-based, stepwise diagonal pressure reduction compensation strategy is proposed. This strategy fully considers the influence of longitudinal and
Zou, YanMa, YaoKong, YanPei, Xiaofei
This paper briefly introduces the vehicle characteristics of four-wheel steering. Based on the parameters of an electric SUV, a linear two-degree-of-freedom vehicle dynamics model is established, and the transfer function of the rear wheel steering angle is derived to keep the sideslip angle at the center of gravity(CoG) constant at zero and proportional to the front wheel steering angle under steady state. The active rear wheel steering control strategy based on zero sideslip angle is established by MATLAB/Simulink, and a co-simulation model is built with CarSim and the HIL test bench to simulate and analyze the proposed control strategy. Subsequently, through classic handling stability test conditions such as the snake test, steering angle step test, and double lane change test, the influence of active rear wheel steering on vehicle dynamic response indicators such as sideslip angle, lateral acceleration, and yaw rate is studied, and the control effect is compared with that of the
Xu, XiangfeiQu, YuanLiu, Jiabao
Based on field investigations of loess slopes along highways in the Lüliang region, a numerical infiltration model of highway loess slopes was established using the ABAQUS finite element software. The study examined the time to plastic zone coalescence and variations in infiltration range under two intense rainfall scenarios for slopes of different heights. Furthermore, a landslide numerical model of the loess slope was constructed using the FEM-SPH method, and a predictive formula for landslide runout distance of highway loess slopes was derived through data fitting.The results indicate that under the same slope height, increased rainfall intensity leads to a certain degree of reduction in landslide runout distance. Conversely, under the same rainfall condition, greater slope height significantly increases the runout distance. This study provides a theoretical foundation and methodological support for stability evaluation and runout distance prediction of loess slopes under intense
Liu, ManfengLi, Hong
Traction control is a critical technique to prevent wheel slip in vehicles, ensuring optimal traction force between the tire and the ground. This study proposes a system that leverages Model-based Predictive Control (MPC) to effectively manage and control longitudinal slip. The proposed system introduces constraints specifically designed to limit longitudinal slip, offering a significant improvement over traditional approaches. The system is evaluated with simulations of a single-corner model, using the Pacejka’s Magic Formula to define the tire force. The results demonstrate the effectiveness of the control in maintaining maximum traction and highlight its advancements compared to previous work.
Rosa, Tobias José Degli EsposteRodrigues, Gustavo SimãoLopes, Elias Dias Rossi
With the rapid development of autonomous driving technology, unmanned ground vehicles (UGVs) are gradually replacing humans to perform tasks such as reconnaissance, target tracking, and search in special scenarios. Omnidirectional mobility based on rapid adjustment of vehicle heading posture enhances the applicability of UGVs in specialized scenarios. Omnidirectional mobility signifies the capability for rapid adjustments to the vehicle’s heading angle, longitudinal velocity, and lateral velocity. Traditional vehicles are constrained by the limitations of under-actuation, which prevents active regulation of lateral movement. Instead, they rely on the coordinated regulation of longitudinal and yaw movements, failing to meet the requirements for omnidirectional mobility. Distributed vehicles featuring steering distributed between the front/rear axles and four-wheel independent drive leverage the over-actuation advantages provided by multi-actuator coordinated control, making them
Chen, GuoyingDong, JiahaoWang, XinyuZhao, XuanmingBi, ChenxiaoGao, ZhenhaiZhang, YanpingHe, Rong
In motorcycle racing and other competitions, there is a technique to intentionally slide the rear wheel to make turns more quickly. While this technique is effective for high-speed riding, it is difficult to execute and carries risks such as falling. Therefore, an anti-sideslip control system that suppresses unintended or excessive sideslip is needed to ensure safe, natural, and smooth turning. In anti-sideslip control, the slip angle is usually used as a control parameter. However, for motorcycles, it is necessary to know the absolute direction of the vehicle's movement. To determine this, GPS or optical sensors are required, but using such sensors for driving is costly and may not provide accurate measurements due to contamination or other environmental factors, making it impractical. Therefore, an anti-sideslip control system was developed by calculating another parameter that indicates the characteristics of the slip angle, without measuring the slip angle itself, thus eliminating
Nakano, KyosukeKawai, KazunoriTakeuchi, Michinori
This paper provides a comprehensive analysis of the evolving requirements and 0[=] technological advancements in high-speed data communication, particularly focusing on slip ring environments and military applications. The study examines the impact of physical properties and construction materials on the bandwidth and signal integrity of traditional contacting passive slip rings, emphasizing the importance of minimizing signal distortion to ensure reliable high-speed data transmission. Various high-speed protocols such as 10 Gigabit Ethernet and SDI are evaluated, highlighting their trade-offs and suitability for different applications. Special attention is given to encoding schemes and techniques to mitigate signal degradation through error correction, signal conditioning, and advanced modulation. Additionally, the paper discusses the critical role of slip ring technology in military platforms, driven by the increasing demands for higher data rates and the complexities of modern
Kouns, Heath
In the context of greenhouse gas emissions (GHG) reduction the most viable short-term solution in the maritime sector is the use of renewable carbon-free fuels. Among these, ammonia represents a possible alternative in compression ignition (CI) engines operating in dual fuel (DF) mode. Although, such fuel features low chemical reactivity, especially in lean mixtures, resulting in poor combustion efficiency, exhaust ammonia slip and low engine performance, DF combustion can be an interesting strategy to overcome such limitations. In this work a wide numerical examination of diesel injection strategies is presented, while ammonia acts as the primary fuel with energy supply around 80%. Since the original marine engine, fuelled with natural gas (NG), presents a single diesel injection, firstly, a pilot injection is added and different diesel mass shares between pilot and main are investigated, by varying the injection rate shape and the pilot start of injection (SOI). Calculations are
Cameretti, Maria CristinaDe Robbio, RobertaPalomba, Marco
This article reviews the key physical parameters that need to be estimated and identified during vehicle operation, focusing on two key areas: vehicle state estimation and road condition identification. In the vehicle state estimation section, parameters such as longitudinal vehicle speed, sideslip angle, and roll angle are discussed, which are critical for accurately monitoring road conditions and implementing advanced vehicle control systems. On the other hand, the road condition identification section focuses on methods for estimating the tire–road friction coefficient (TRFC), road roughness, and road gradient. The article first reviews a variety of methods for estimating TRFC, ranging from direct sensor measurements to complex models based on vehicle dynamics. Regarding road roughness estimation, the article analyzes traditional methods and emerging data-driven approaches, focusing on their impact on vehicle performance and passenger comfort. In the section on road gradient
Chen, ZixuanDuan, YupengWu, JinglaiZhang, Yunqing
The unicycle self-balancing mobility system offers superior maneuverability and flexibility due to its unique single-wheel grounding feature, which allows it to autonomously perform exploration and delivery tasks in narrow and rough terrains. In this paper, a unicycle self-balancing robot traveling on the lunar terrain is proposed for autonomous exploration on the lunar surface. First, a multi-body dynamics model of the robot is derived based on quasi-Hamilton equations. A three-dimensional terramechancis model is used to describe the interaction between the robot wheels and the lunar soil. To achieve stable control of the robot's attitude, series PID controllers are used for pitch and roll attitude self-balancing control as well as velocity control. The whole robot model and control strategy were built in MATLAB and the robot's traveling stability was analyzed on the lunar terrain.
Shi, JunweiZhang, KaidiDuan, YupengWu, JinglaiZhang, Yunqing
Vehicle sideslip is a valuable measurement for ground vehicles in both passenger vehicle and racing contexts. At relevant speeds, the total vehicle sideslip, beta, can help drivers and engineers know how close to the limits of yaw stability a vehicle is during the driving maneuver. For production vehicles or racing contexts, this measurement can trigger Electronic Stability Control (ESC). For racing contexts, the method can be used for driver training to compare driver techniques and vehicle cornering performance. In a fleet context with Connected and Autonomous Vehicles (CAVS) any vehicle telemetry reporting large vehicle sideslip can indicate an emergency scenario. Traditionally, sideslip estimation methods involve expensive and complex sensors, often including precise inertial measurement units (IMUs) and dead reckoning, plus complicated sensor fusion techniques. Standard GPS measurements can provide Course Over Ground (COG) with quite high accuracy and, surprisingly, the most
Hannah, AndrewCompere, Marc
The flow resistivity is a critical parameter for evaluating the acoustic performance of the porous materials. Accurate determination of flow resistivity is essential for predicting the characteristic impedance and propagation constants of materials. In this paper, a method is proposed to calculate the flow resistivity of kapok fiber felt, aiming to accurately assess the flow resistivity of kapok fiber felt. Based on the dual-porosity equivalent model of kapok fiber felt, it is hypothesized that the flow resistivity is divided into two components. One part from the large pores between fibers, and the other part from the hollow structures within kapok fibers and the micropores on the fiber walls. The contribution of the large pores between fibers to the flow resistivity is calculated using the Tarnow_S model. Meanwhile, the hollow pores within the kapok fibers and the micropores on the fiber walls are represented as an equivalent pore. The slip effects are considered, and experimental
Lin, JiamanKang, YingziXie, XinxingZhang, QuYang, ShanmiaoShangguan, Wen-Bin
With the advancement of intelligent transportation and smart logistics systems, tractor semi-trailers have gradually become one of the primary modes of transport due to their substantial cargo capacity. However, the growing number of tractor semi-trailers has raised significant traffic safety concerns. Due to their significant spring mass and strong body strength, accidents involving tractor semitrailers often result in severe consequences. Active collision avoidance control strategies provide assurance for vehicle safety. However, existing research predominantly focuses on passenger cars and small commercial vehicles. Research specifically addressing tractor semi-trailers, which have longer bodies and more complex dynamic characteristics, is relatively sparse. Therefore, this paper proposes a collision risk assessment-based longitudinal collision avoidance control strategy for tractor semi-trailers with slip ratio control. Firstly, the paper introduces the braking characteristics and
Yan, YangZheng, HongyuZhang, Yuzhou
Since most of the existing studies focus on the identification of the yaw stable region, but ignore the identification of the roll stable region, this article presents a software tool YRSRA for calculating both the yaw and roll stable region for ground vehicle system with 5G-V2X. And the frequency of rollover instability of commercial vehicles such as trucks and buses is not low, and the cost of rollover accidents is often greater than the cost of yaw instability accidents. Therefore, it is necessary to identify the stability region of yaw and roll at the same time. Firstly, the iterative model of yaw rate and slip angle is constructed through deducing the two-degree-of-freedom vehicle dynamics. Secondly, the load transfer ratio (LTR) is coded with given yaw rate and slip angle. Thirdly, several Illustrative examples are depicted, such as variation of steer angle, road adhesion coefficient and vehicle speed. The software features an easy to generate yaw and roll stability region by on
Tu, LihongZeng, DequanZhang, ZhoupingHe, QixiaoZhao, ShuqiSun, JingWang, AichunYu, QinMing, JinghongWang, XiaoliangHu, Yiming
The Distributed Drive Electric Vehicles (DDEVs) offer advantages such as independently controllable driving and braking forces at each wheel, rapid response, and precise control. These features enable effective electronic stability control (ESC) by appropriately distributing torque across each wheel. However, traditional ESC systems typically employ single-wheel hydraulic differential braking, failing to fully utilize the independent torque control capabilities of DDEVs. This study proposes a hierarchical control strategy for distributed driving and braking ESC based on particle filter (PF) and fuzzy integral sliding mode control (FISMC). First, the vehicle state estimation layer uses a three-degree-of-freedom vehicle model and the PF to estimate sideslip angle and vehicle speed. Next, the target torque decision layer includes a target speed tracking controller and a yaw moment decision controller. The yaw moment decision controller uses the FISMC to determine additional yaw moment by
Li, XiaolongZheng, HongyuKaku, Chuyo
As a crucial tool for lunar exploration, lunar rovers are highly susceptible to instability due to the rugged lunar terrain, making control of driving stability essential during operation. This study focuses on a six-wheel lunar rover and develops a torque distribution strategy to improve the handling stability of the lunar rover. Based on a layered control structure, firstly, the approach establishes a two-degree-of-freedom single-track model with front and rear axle steering at the state reference layer to compute the desired yaw rate and mass center sideslip angle. Secondly, in the desired torque decision layer, a sliding mode control-based strategy is used to calculate the desired total driving torque. Thirdly, in the torque distribution layer, the optimal control distribution is adopted to carry out two initial distributions and redistribution of the drive torque planned by the upper layer, to improve the yaw stability of the six-wheeled lunar rover. Finally, a multi-body dynamics
Liu, PengchengZhang, KaidiShi, JunweiYang, WenmiaoZhang, YunqingWu, Jinglai
The research object of this project is the anti-slip and lateral stability control technique for a distributed three-axis drive vehicle. What differs from the traditional four-motor power system layout is that the third axle has two motors, while the second axle only has one motor. Compared with the traditional design, this layout can reduce dependence on battery performance and maintain motor operation in a high-efficiency range by switching between different operating modes. For example, when driving at high speeds, only the motor on the second axle works, which can improve motor efficiency. When accelerating or climbing, all motors work to provide a large power output. In the research, the vehicle model was first established in Simulink, and then co-simulated with TruckSim. The drive anti-slip control first identified the optimal slip rate for the road, and then used the sliding mode control to determine the driving torque for each wheel, achieving good control effects under various
Shen, RuitengZheng, HongyuKaku, ChuyoZong, Changfu
In future planetary exploration missions, the Eight-Wheeled Planetary Laboratory (EWPL) will have sufficient capacity for tasks but will experience significant lateral slips during high-speed turns due to its large inertia. Modern technology allows for independent steering of all eight wheels, but controlling each wheel's steering angle is key to improving stability during turns. This paper introduces a novel rear-axle steering feed-forward controller to reduce sideslip. First, a mathematical model for the vehicle's steering is established, including kinematic equations based on Ackermann steering. Feed-forward zero side-slip control is applied to the third and fourth axles to counteract the side-slip angle of the center of mass. A multi-body dynamics model of the EWPL is then built in Chrono to evaluate the turning radius and optimize steering angle ratios for the rear axles. Finally, a steady-state cornering simulation on loose terrain compares the performance of the proposed
Liu, JunZhang, KaidiShi, JunweiYang, WenmiaoZhang, YunqingWu, Jinglai
Under extreme driving conditions, such as emergency braking, rapid acceleration, and high-speed cornering, the tire, as the vehicle’s only direct connection to the road, plays a critical role in influencing dynamic performance and driving stability. Accurately predicting and tire longitudinal force under such combined slip conditions is key to improving vehicle control precision and ensuring driving safety. This study proposes a tire longitudinal force estimation strategy based on an intelligent tire system. The core of this system consists of three integrated PVDF (Polyvinylidene Fluoride) sensors embedded in the tire, which, due to their exceptional sensitivity, can precisely capture dynamic deformation information of the tire under varying conditions. This provides real-time, detailed data to better understand the complex interaction forces between the tire and the road. To study and validate the longitudinal force estimation model, the research team employed a high-precision indoor
Zhang, ZipengXu, NanTang, ZepengChen, Hong
In response to the complex shore slope road conditions and the switching of water–land environments during the amphibious vehicle’s landing process, a landing drive force control strategy for amphibious vehicles is proposed. First, based on the shore slope gradient, buoyancy effect, and amphibious vehicle acceleration, the drive force of the front and rear wheels of the amphibious vehicle is pre-allocated. Then, referring to the road parameters of common road types, the road adhesion coefficient and optimal slip ratio of the current road surface where the amphibious vehicle is located are identified based on the principle of fuzzy control. Subsequently, with the slip ratio difference as the control target, the drive motor is controlled based on the sliding mode control algorithm to achieve tracking of the optimal slip ratio. A joint simulation is carried out using CarSim and Simulink, and the results are compared with those without control. The simulation results show that the drive
Huang, BinYuan, ZinengYu, Wenbin
The sideslip angle and tire-road peak adhesion coefficient (TRPAC) are crucial parameters for intelligent active safety systems in automobiles. The accuracy and real-time estimation of these parameters significantly affect control effectiveness. And there is a strong coupling between the two parameters, which brings great challenges to the joint estimation. This paper proposes a nonlinear dynamic estimator that pre-estimates tire lateral force to achieve synchronous estimation of sideslip angle and TRPAC. Additionally, to cope with sudden changes in road adhesion condition, a TRPAC preliminary estimation optimization algorithm is introduced. Moreover, an adaptive gain adjustment algorithm for the sideslip angle estimator is implemented to address large lateral excitation conditions. Simulation results on various road surfaces and under various lateral excitation conditions demonstrate that the proposed joint estimator enables accurate and rapid estimation of sideslip angle and TRPAC.
Zhao, WenruiLeng, BoHan, YinfengYu, ZhuopingXiong, Lu
Torque vectoring offers drive flexibility and continuous individual wheel torque regulation, which is unavailable in conventional transmission systems. Electric vehicles with multiple drivetrains and torque-vectoring system can significantly enhance vehicle response and handling, and thus the active safety, efficiency, and performance of the vehicle in all driving conditions. The current methodology of predicting performance characteristics is limited through slip rate calculations and yaw rate calculations. The vehicle dynamic performance evaluations with above said methodologies holds good for dynamic cornering. But in the scenarios where the vehicle moving in straight drive with different wheel traction requirements on either side (split-μ condition) and that requires torque vectoring. These above methods do not help to evaluate the performance of vehicle. Because these methodologies are based on predicting dynamic center-of-gravity values of vehicle. In the proposed methodology
Ramakrishnan, Gowtham RajBaheti, Palash
The undercarriage is a critical component in machines such as crawlers, excavators, and compact track loaders. It includes vital elements such as the track frame, chain guides, rollers, track chains, idlers, carrier rollers, final drive, and sprockets. Among all these machines, crawler dozers encounter harsh environments with various ground conditions. During operations, the chains are subjected to traverse and side loads, which cause the chains to tend to slip out of the bottom rollers. The chain guide plays a crucial role in assisting and maintaining the chain in the correct position. The forces acting on chain guides are influenced by factors such as track chain tension, roller wear, chain link wear, and counter-rotation (where one track moves forward while the other moves in reverse). Among all the load cases, there are two critical load cases which are vital to be studied in order to determine the required number of chain guides along with other attributes like profile or section
Masane, NishantBhosale, DhanajiSarma, Neelam K
To enhance vehicle dynamic stability during driving, we developed a three-dimensional phase space model that incorporates the sideslip angle of center of mass, yaw rate, and lateral load transfer rate. This model enabled real-time evaluation and active control of vehicle stability. First, longitudinal and lateral controllers were implemented to ensure precise vehicle trajectory. Second, a hierarchical control strategy was designed to actively manage the desired sideslip angle, yaw rate, and roll angle based on the vehicle’s destabilizing conditions, thereby maintaining the vehicle within a stable state space. We simulated and tested the stability analysis methods and integrated control strategies for both cars and trucks under DLC (double lane change) and CDC (circular driving condition) scenarios using joint simulations with CarSim/TruckSim and Simulink. The proposed integrated stability control strategy, which combined MPC-based trajectory tracking with direct yaw moment control and
Lai, FeiXiao, HaoHuang, Chaoqun
As an important part of the automobile electronic control system, the acceleration slip regulation takes the tire slip rate as the main control target. By controlling the wheel driving force, the tire maintains a stable adhesion state to obtain good driving stability and power. This paper takes battery electric vehicles as the research object and explores the application of acceleration slip regulation in vehicle drive control. In order to obtain the true vehicle speed when the wheel slips, a vehicle speed observer based on extended Kalman Filter is proposed. Secondly, this paper designs a road surface recognition method based on fuzzy theory, which obtains the optimal slip rate under current road conditions by taking the actual slip rate and road surface adhesion coefficient as input. When a vehicle is driving on a road with different adhesion coefficients on the left and right sides, one side of the wheel may slip severely while the opposite side wheel does not slip. In order to
Kang, KaileiLiu, XingchenLiu, XinHong
After the COVID-19 pandemic, leisure activities and cultures have undergone significant transformations. Particularly, there has been an increased demand for outdoor camping. Consequently, the need for capabilities that allow vehicles to navigate not only paved roads but also unpaved and rugged terrains has arisen. In this study, we aim to address this demand by utilizing AI to introduce a 'Stuck Probability Estimation Algorithm' for vehicles on off-road. To estimate the 'Stuck Probability' of a vehicle, a mathematical model representing vehicle behavior is essential. The behavior of off-road driving vehicles can be characterized in two main aspects: firstly, the harshness of the terrain (how uneven and rugged it is), and secondly, the extent of wheel slip affecting the vehicle's traction. To achieve this, we constructed two AI learning models to quantify each aspect of vehicle behavior, and integrated them into a single computational meta-model to create the 'Stuck Score Calculation
Kang, Junhanbyun, JijunJin, UmHuh, KunsooYang, Chanuk
This paper proposes a thorough investigation of steady-state cornering equilibria for cars. Besides equilibria corresponding to normal driving behaviour - herein denoted as stable-normal turn, drifting is attracting increasing attention. When discussing drifting, it is typically assumed that yaw rate and steering angle have opposite signs, i.e. the driver is countersteering, and the rear axle is saturated. Interestingly, another unstable equilibrium is possible, herein referred to as unstable-normal turn. In this work, an attempt to give a comprehensive definition of drift is made. An inverse model is proposed to compute the driver inputs needed to perform a steady-state turn for a given radius and sideslip angle. The mathematical meaning of all equilibria is explored by linearizing the system and analyzing eigenvalues and eigenvectors of the resulting state matrices.
Righetti, GiovanniBinetti, ElisabettaPinto de Castro, RicardoLot, RobertoMassaro, MatteoLenzo, Basilio
This paper presents a torque distribution strategy for four-wheel independent drive electric vehicles (4WIDEVs) to achieve both handling stability and energy efficiency. The strategy is based on the dynamic adjustment of two optimization objectives. Firstly, a 2DOF vehicle model is employed to define the stability control objective for Direct Yaw moment Control (DYC). The upper-layer controller, designed using Linear Quadratic Regulator (LQR), is responsible for tracking the target yaw rate and target sideslip angle. Secondly, the lower-layer torque distribution strategy is established by optimizing the tire load rate and motor energy consumption for dynamic adjustment. To regulate the weights of the optimization targets, stability and energy efficiency allocation coefficient is introduced. Simulation results of double lane change and split μ road conditions are used to demonstrate the effectiveness of the proposed DYC controller.
Dou, JingyangChen, ZixuanZhang, YunqingWu, Jinglai
Intelligent tyres can offer crucial insights into tyre dynamics, serving as a fundamental information source for vehicle state estimation and thereby enabling vehicular safety control. Among the numerous tyre parameters, slip ratio stands out as a direct influencer of vehicle motion characteristics. Accurate estimation of tyre slip ratio is essential for vehicle safety. Firstly, an analysis of the fundamental composition of tyres was conducted, and appropriate simplifications were applied to the tyre structure. Additionally, a finite element model of the tyre was constructed using ABAQUS software. To validate the reliability of the model, a real vehicle testing system was established, consisting of the experimental vehicle, data acquisition system, and supervisory computer. The reliability of the finite element model was confirmed by assessing the consistency of acceleration signals in three different directions of the tyre. Secondly, the variations in acceleration curves under
Li, BoGu, TianLiBei, ShaoyiGuo, JinfeiWalid, DaoudYi, AibinZhu, Yunhai
The pursuit of maintaining a zero-sideslip angle has long driven the development of four-wheel-steering (4WS) technology, enhancing vehicle directional performance, as supported by extensive studies. However, strict adherence to this principle often leads to excessive understeer characteristics before tire saturation limits are reached, resulting in counter-intuitive and uncomfortable steering maneuvers during turns with variable speeds. This research delves into the phenomenon encountered when a 4WS-equipped vehicle enters a curved path while simultaneously decelerating, necessitating a reduction in steering input to adapt to the increasing road curvature. To address this challenge, this paper presents a novel method for dynamically regulating the steady-state yaw rate of 4WS vehicles. This regulation aims to decrease the vehicle's sideslip angle and provide controlled understeer within predetermined limits. As a result, the vehicle can maintain a zero-sideslip angle during turns with
Guan, YihangZhou, HongliangJing, HouhuaMiao, Weiwei
The global energy crisis and drastic climate change are continuously promoting the implementation of sustainable energy sources. To meet the emission standards and carbon-neutrality targets in vehicle industry, ammonia is considered to be one of the promising carbon-neutral fuels. However, running the engines on high amounts of ammonia may lead to significantly high ammonia slip. This originates huge safety concerns. Therefore, hydrogen is added in certain ratio with ammonia to promote combustion and reduce ammonia slip. Furthermore, adding diesel as a pilot fuel further facilitates the combustion reactions. This experimental study investigated the effect of different ammonia-hydrogen blend ratios on in-cylinder pressure, heat release rate, cumulative heat release, indicated mean effective pressure (IMEP), indicated thermal efficiency (ITE), CA5 and CA50. This effect of blend ratios was tested for varied diesel pilot amounts and timings. The results show that increasing the hydrogen
Akram, Muhammad SaadCheng, QiangYeganeh, MaryamKaario, OssiLarmi, Martti
Due to the presence of uncertain disturbances in the actual steering system, disturbances in the system may affect the handling stability of the vehicle. Therefore, this article proposes an integrated steering system control strategy with stronger anti-disturbance performance. When disturbances exist in the system, the proposed control strategy effectively reduces the attitude changes during the vehicle steering process. In the upper-level control strategy, a variable transmission ratio curve is designed to coordinate the high-speed handling stability and low-speed steering sensitivity of the vehicle. On this basis, a sideslip angle observer is proposed based on the extended state observation theory, which does not depend on an accurate system model, thus determining the intervention timing of the active front wheel steering system. In the lower-level control strategy, DR-PI/DR-PID controllers are designed for the integrated steering system. Finally, experiments are conducted in the
Wei, JinChengZheng, Zhu’AnChen, JiaLing
Amphibious vehicles with both land and water navigation functions have extremely high application value in the military and civilian fields. In order to fully utilize the wheel driving force and ensure the smooth landing of the amphibious vehicle driven by four wheel hub motor, an acceleration slip regulation (ASR) is designed under the condition of landing from water. First, the road friction coefficient is identified based on the back propagation neural network (BPNN). Then, utilizing the improved Burckhardt model, the current optimal slip ratio is calculated from the identified road friction coefficient. Finally, the ASR under the condition of landing from water is designed based on radial basis function (RBF) single neuron adaptive PID control algorithm. By analyzing the process of amphibious vehicles transitioning from water to land, a typical working condition for amphibious vehicles landing is established, and a joint simulation is conducted using CarSim/Simulink. The simulation
Huang, BinXu, JialuoYuan, ZhijunWei, Lexia
An automatic collision avoidance control method integrating optimal four-wheel steering (4WS) and direct yaw-moment control (DYC) for autonomous vehicles on curved road is proposed in this study. Optimal four-wheel steering is used to track a predetermined trajectory, and DYC is adopted for vehicle stability. Two single lane change collision avoidance scenarios, i.e., a stationary obstacle in front and a moving obstacle at a lower speed in the same lane, are constructed to verify the proposed control method. The main contributions of this article include (1) a quintic polynomial lane change trajectory for collision avoidance on curved road is proposed and (2) four different kinds of control method for autonomous collision avoidance, namely 2WS, 2WS+DYC, 4WS, and 4WS+DYC, are compared. In the design of DYC controller, two different feedback control methods are adopted for comparison, i.e., sideslip angle feedback and yaw rate feedback. The simulation results demonstrate significant
Lai, Fei
The automotive industry has recently started implementing magnetic gears, in different types, as an alternative design for transmission systems. One such design being the Magnetic planetary gear permanent magnet (MPG-PM) machine. The current methodology and the relevant formulae help to design the magnetic planetary gear system, which does not have design considerations for permanent magnet machines and the influence of magnetic fields. The influence of design characteristics of PM machine, Magnetic field and its material plays a vital role in designing the MPG-PM for electric vehicle applications. A method of optimizing the Gear topology design parameters of a magnetic planetary gear permanent magnet machine (MPG-PM machine) is proposed. The Analytical calculations regarding the design parameters are proposed in relation to power, gear ratios, and other design constraints like packaging parameters i.e., outer diameter, the overall length of the machine. The analytical calculation
Ramakrishnan, Gowtham Raj
To address the challenge of directly measuring essential dynamic parameters of vehicles, this article introduces a multi-source information fusion estimation method. Using the intelligent front camera (IFC) sensor to analyze lane line polynomial information and a kinematic model, the vehicle’s lateral velocity and sideslip angle can be determined without extra sensor expenses. After evaluating the strengths and weaknesses of the two aforementioned lateral velocity estimation techniques, a fusion estimation approach for lateral velocity is proposed. This approach extracts the vehicle’s lateral dynamic characteristics to calculate the fusion allocation coefficient. Subsequently, the outcomes from the two lateral velocity estimation techniques are merged, ensuring rapid convergence under steady-state conditions and precise tracking in dynamic scenarios. In addition, we introduce a tire parameter online adaptive module (TPOAM) to continually update essential tire parameters such as
Chen, GuoyingYao, JunGao, ZhenhaiGao, ZhengWang, XinyuXu, NanHua , Min
Accurate estimation of traction force is essential for the development of advanced control systems, particularly in the domain of autonomous driving. This study presents an innovative approach to enhance the estimation of tire–road interaction forces under combined slip conditions, employing a combination of empirical models and neural networks. Initially, the well-known Pacejka formula, or magic formula, was adopted to estimate tire–road interaction forces under pure longitudinal slip conditions. However, it was observed that this formula yielded unsatisfactory results under non-pure slip conditions, such as during curves. To address this challenge, a neural network architecture was developed to predict the estimation error associated with the Pacejka formula. Two distinct neural networks were developed. The first neural network employed, as inputs, both longitudinal slip ratios of the driving wheels and the slip angles of the driving wheels. The second network utilized longitudinal
Marotta, RaffaeleStrano, SalvatoreTerzo, MarioTordela, Ciro
This SAE Recommended Practice is intended as the definition of a standard test, which may be subject to frequent change to keep pace with experience and technical advances. This should be kept in mind when considering its use. The SAE No. 2 friction test is used to evaluate the friction characteristics of automatic transmission plate clutches with automotive transmission fluid combinations. The specific purpose of this document is to define a µPVT test for the evaluation of the variation of wet friction system low speed slip characteristics as a function of speed, temperature, and pressure. This procedure is intended as a suggested method for both suppliers and end users. The only variables selected by the supplier or user of the friction system are: Friction material Fluid Reaction plates Oil flow (optional) These four variables must be clearly identified when reporting the results of this test. If any of the test parameters or system hardware as described in this document are changed
Automatic Transmission and Transaxle Committee
The objective of this study was to investigate the change of relative local velocity in each pulley groove at sliding between the belt and pulleys for a metal-pushing V-belt type CVT where micro elastic slips were inevitably accompanied to transmit power, while the transmissions were widely adopted to provide comfortable driving by continuously automatically adjusting the speed ratio. Local changes of wrapping radial position and velocity of the belt in each pulley groove of the CVT were simultaneously measured by a potentiometer with a spinning roller in the experiments. The mechanical power generated by the AC motor was transmitted through the CVT unit from the driving axis to the driven axis as usual under practical conditions while the speed ratio was set to 1.0. Pulley clamping force was applied by oil pressure. Test results showed that the wrapping radial position of the belt was slightly decreased at the location from the entrance to the exit in the driving pulley groove and
Kamiya, TakuObunai PhD, KiyotakaOkubo, Kazuya
Porous wall permeability is one of the most critical factors for the estimation of backpressure, a key performance indicator in automotive particulate filters. Current experimental and analytical filter models could be calibrated to predict the permeability of a specific filter. However, they fail to provide a reliable estimation for the dependence of the permeability on key parameters such as wall porosity and pore size. This study presents a novel methodology for experimentally determining the permeability of filter walls. The results from four substrates with different porosities and pore sizes are compared with several popular permeability estimation methods (experimental and analytical), and their validity for this application is assessed. It is shown that none of the assessed methods predict all permeability trends for all substrates, for cold or hot flow, indicating that other wall properties besides porosity and pore size are important. The hot flow test results show an
Samuels, CallumHoltzman, RanBenjamin, StephenAleksandrova, SvetlanaWatling, Timothy C.Medina, Humberto
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