Browse Topic: Steering systems

Items (2,145)
Objective: Previous studies have reported disparity in injuries between male and female drivers in the risk of certain types of injuries in frontal crashes that may be due to a myriad of sex-related differences, including body size, shape, anatomy, or sitting posture. The objectives of this study are 1) to use mesh-morphing methods to generate a diverse set of human body models (HBMs) representing a wide range of body sizes and shapes for both sexes, 2) conduct population-based frontal crash simulations, and 3) explore adaptive restraint design strategies that may lead to enhanced safety for the whole population while mitigating potential differences in injury risks between male and female drivers Method: A total of 200 HBMs with a wide range of body sizes and shapes were generated by morphing the THUMS v4.1 midsize male model into geometries predicted by the statistical human geometry models. Ten male and ten female HBMs were selected for population-based simulations. An existing
Sun, WenboHu, JingwenLin, Yang-ShenBoyle, KyleReed, MatthewSun, ZhaonanHallman, Jason
The road infrastructure in India has complex navigational challenges with most of the road unstructured especially in rural areas. Decision-making becomes a challenge for drivers in unpredictable environments such as narrow roads, flooded roads and heavy traffic. In this paper, an Augmented Reality based ML-Algorithm for Driver Assistance (ARMADA) has been proposed that improves awareness to safely maneuver in these conditions. The methodology for development and validation of this Augmented Reality (AR) based algorithm contains multiple steps. Firstly, extensive data collection is conducted using real time recording and benchmark datasets like Berkeley Deep Drive (BDD) and Indian Driving Dataset (IDD). Secondly, collected data are annotated and trained using an optimal machine learning (ML) model to accurately identify the complex scenario. In third step, an ARMADA algorithm is developed, integrating these models to estimate road widths, detect floods and provide seamless driver
Anandaraj, Prem RajSivakumar, VishnuThanikachalam, GaneshL, RadhakrishnanMotoki, YaginumaSelvam, Dinesh Kumar
Nowadays, customers expect excellent cabin insulation and superior ride comfort in electric vehicles. OEMs focus on fine tuning the suspension system in electric vehicle to isolate the road induced shocks which finally offers superior ride quality. This paper focuses on enhancing the ride comfort by reducing the road excitation which originates mainly due to road inputs. Higher steering wheel vibration is perceived on the test vehicle on rough road surfaces. To determine the predominant force transfer path, Multi reference Transfer Path Analysis (MTPA) is performed on the front and rear suspension. Based on the finding from MTPA, various recommendations are explored and the effect of each modification is discussed. Apart from this, Operational Deflection Shape (ODS) analysis is used to determine the deflection shape on the entire steering system . Based on ODS findings, recommendations like dynamic stiffness improvements on the steering column and steering wheel are explored and the
S, Nataraja MoorthyRao, ManchiSelvam, EbinezerRaghavendran, Prasath
Rack load estimation during the pre-design stages is critical for the calibration of steering systems, particularly in achieving the desired steering feel and optimizing assistance strategies in Electric Power Assisted Steering (EPAS). Conventional approaches often depend on physical vehicle testing or simplified empirical equations, which may be time-consuming or lacks the fidelity required for early-stage analysis. This paper presents a 1D simulation strategy to address limitations from conventional approaches. The proposed rack force estimation model is based on multi-physics analytical equations that calculate tire-road friction forces and the resulting moments about the steering axis, delivering a physics-based yet computationally efficient solution. The rack force estimation model is further extended into EPAS system model by incorporating Direct Current (DC) brushed motor model. The rack force estimation model is validated against physical test data which demonstrates a high
Adsul, SourabhIqbal, Shoaib
This paper presents the design and implementation of a Semi-Autonomous Light Commercial Vehicle (LCV) capable of following a person while performing obstacle avoidance in urban and controlled environments. The LCV leverages its onboard 360-degree view camera, RTK-GNSS, Ultrasonic sensors, and algorithms to independently navigate the environment, avoiding obstacles and maintaining a safe distance from the person it is following. The path planning algorithm described here generates a secondary lateral path originating from the primary driving path to navigate around static obstacles. A Behavior Planner is utilized to decide when to generate the path and avoid obstacles. The primary objective is to ensure safe navigation in environments where static obstacles are prevalent. The LCV's path tracking is achieved using a combination of Pure Pursuit and Proportional-Integral (PI) controllers. The Pure Pursuit controller is utilized as lateral control to follow the generated path, ensuring
Ayyappan, Vimal RajDhanopia, RashmiAli, AshpakN, RageshSato, Hiromitsu
Elastomeric materials are essential in advanced automotive engineering for mobility, isolation, damping, fluid transfer (cooling, steering, fuel, and brake), and sealing because of their unique physio mechanical properties. Elastomers are commonly used in both static and dynamic components, such as hoses, mounts, bushes, and tires. Engine emission standards and weight optimization have caused higher temperature exposure conditions for automotive components. The steering system uses special purpose elastomers like Chlorinated Polyethylene that can deteriorate under abnormal conditions during vehicle operation or manufacturing process due to the high temperature exposure. Therefore, it is crucial to understand the causes and consequences of thermal degradation of elastomers. Thermal degradation is a significant phenomenon that changes the physiochemical properties of elastomers, which results in a product not meeting functional requirements. This study investigates the thermal
Thiruppathi, AnandhiMishra, NitishKrishnamoorthy, Kunju
In the initial stages of a vehicle development program, the sizing of various components is a critical deliverable. The steering system, in particular, requires a precise estimation of the rack load for the appropriate sizing of the rack and assists units. Accurately predicting the load on the system during the early stages of development is challenging, especially in the absence of benchmark or legacy data. Commonly used processes for estimating parking steering effort often employ simplistic approaches that may fail to account for parameters such as tire size, vertical stiffness, and steering geometry, leading to reduced accuracy. This paper introduces an advanced methodology for predicting steering rack loads, which incorporates considerations such as contact patch size and pressure variation, as well as the tire jacking effect. The methodology involves mathematical modeling of the contact patch using mesh-grids, utilizing common inputs available in the early stages of vehicle
Shirke, UmeshDabholkar, AniruddhBardia, VivekSrivastava, HarshitPrasad, Tej Pratap
In traditional commercial vehicles with leaf spring suspension and Recirculating Ball Joint (RCBT) steering systems often experience undesirable pulling due to unsymmetrical steering mechanism during braking, especially when the suspension and steering hardpoints are not properly tuned. This work analyzes the mechanisms responsible for pulling tendencies, primarily addressing brake steer and bump steer, which occur due to misalignments in the suspension and steering geometries. Brake steer occurs when braking forces create an imbalance in torque, resulting in the vehicle deviating to one side. On the other hand, bump steer refers to the unwanted changes in the wheel alignment when the suspension undergoes travel, leading to instability or unintended steering input. These two phenomena, if not controlled, can result in undesirable vehicle handling, especially under heavy braking conditions. This work focuses on evaluating these mechanisms and suggests strategies for minimizing their
Pandhare, Vinay RamakantM, Anantha PadmnabhanNizampatnam, BalaramakrishnaLondhe, AbhijitDoundkar, Vikas
To export India based SUVs to European markets, change in steering position is required to suit vehicle driving condition. Ideally, RHD and LHD variants of the same vehicle should have similar levels of ride and handling performance parameters. However, due to various packaging constraints and regulations, there is a possibility of minor change in Hard-points of steering or suspension system which may lead to different behavior in terms of body roll and steering response. While cornering or double lane change maneuvers, difference in steering phase angles or steering stiffness or suspension hardpoints results in different roll behavior as well as understeer characteristics of the vehicle. The present study shows key parameters and optimization methodology to maintain same level of ride and handling performance in both RHD and LHD variants. Objective measurements and physical kinematics and compliance tests were carried out with various configurations of RHD and LHD variants to
Hussain, Inzamam UlKamarthi, AshwinRewale, PratikNehal, S BRasal, ShraddheshNaidu, Kethireddi
Born Electric SUVs is gaining immense popularity due to enhanced ride and handling characteristics, advanced tech features elevating both performance and customer experience to an elite standard. Due to the platform constraints, the vehicle adopts a Front Wheel Drive (FWD) layout with a rear twist beam configuration, housing the electric motor at the front to deliver drive torque directly to the front wheels. Torque steer is a phenomenon often found in FWD cars, which is unsettling to driver where the steering wheel could be pulled hard to one side when there is aggressive throttle input potentially leading to deviation of the vehicle from its desired path. In contrast to internal combustion engines (ICEs), electric motors provide an instantaneous torque, something that can worsen torque steer if not well addressed. However, torque steer remains a key concern, with high torque output of electric motors especially for a front wheel drive vehicle. This paper introduces a methodology to
Prabhakara Rao, VageeshWankhade, KrishnaThakur, PragyeshRasal, ShraddheshAsthana, Shivam
Path planning is a key element of autonomous vehicle navigation, allowing vehicles to calculate feasible paths in challenging environments for applications like automated parking and low speed autonomous driving. Algorithms such as Hybrid A*, Reeds-Shepp, and Dubins paths are widely used and can generate collision-free paths but tend to create curvature discontinuities. These discontinuities result in sudden steering transitions, which create control instabilities, higher mechanical stress, and lower passenger comfort. To overcome these issues, this paper suggests a path-smoothing technique based on the pure-pursuit algorithm to produce smoothed curve paths appropriate for real-world driving. This method utilizes the practical approach of the original path, but removes sudden transitions that destabilize control. By ensuring smooth curvature, the vehicle undergoes fewer jerky steering actions, improved energy efficiency, less actuator wear, and improved high-speed tracking. This paper
S, ShriniyathiA, JosanaEdwin J, JoelT, AkshayaaM, Senthil VelKumar, Vimal
Modern automotive systems are becoming increasingly complex, comprising tightly integrated hardware and software components with varying safety implications. As the demand for ISO 26262 compliance grows, performing efficient and consistent Hazard Analysis and Risk Assessment (HARA) across these layers presents both methodological and practical challenges. Traditional approaches often involve performing HARA for an item (where item maybe a system or a combination of systems), which can lead to update of HARA for every new feature addition in an item, which in turn may lead to analysis of same functions in multiple HARAs leading to inconsistent risk categorization, redundancy, or even conflicting safety goals. Therefore, this paper proposes a unique HARA methodology which consolidates the list of functions from various systems and performs the HARA for the grouped functions (hereby referred to as Cluster HARAs). For example, Electrical power steering, Electric pump powered hydraulic
Somasundaram, ManickamVijayakumar, Melvin
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
Vehicles with a high center of gravity (CG) and moderate wheel track, like compact Sport Utility Vehicles (SUVs), have a relatively low Static Stability Factor (SSF) and thus are inherently less stable and more susceptible to rollover crashes. Moreover, to be more maneuverable in highly populated urban areas, a smaller Turning Circle Diameter (TCD) is necessary. Here, Variable Gear Ratio (VGR) steering systems have major benefits over traditional Constant Gear Ratio (CGR) systems in terms of enhancing both roll stability and agility. To adapt VGR steering systems to a particular vehicle dynamic, Full Vehicle (FV) and Driver-in-the-Loop (DIL) simulations are utilized. Using this method, exact calibration is possible according to realistic driving conditions so that the VGR steering C-factor curve is properly tuned for optimal handling in on-center, off-centre, and transitional areas of the Steering Wheel Angle (SWA). Primary performance measures—e.g., SWA gradients at different lateral
Rewale, PratikKopiec, JakubKumar, DevaRasal, ShraddheshHussain, InzamamNehal, S B
Steering I-shaft with rubber coupling (or hardy disc) is an important part of complete steering system mainly in body on frame (BOF) vehicles. Hardy discs are used to dampen the vibrations that transmit to steering wheel through frame, steering gear and I-shaft. They also support to accommodate the variation between frame and BIW (Body in white) of body on frame vehicles. They are made up of rubber or other polymer composites, which have less torsional stiffness as compared to metals. The overall torsional stiffness of steering system reduces since the hardy disc is used in series in steering system, that impacts on the overall performance of steering system. So, during development of I shafts with different design, stiffness of hardy discs are used to optimize the steering and NVH performance of vehicle. Considering the development time and cost, each design of I-shaft cannot be validated at vehicle level. The torsional and axial force or displacement of hardy disc is measured at
Kabdal, Amit
Body-on-frame vehicles are well-regarded for their durability and off-road capabilities, but their structural design often makes them more vulnerable to noise, vibration, and harshness (NVH) issues. Vibrations originating from uneven roads are transmitted through the suspension and steering assemblies, sometimes resulting in rattles or other disturbances. These vibrations can be amplified by the inherent flexibility in the body-to-frame mounting system. In such vehicles, the steering system plays a critical role in driver comfort and is highly sensitive to vibrational inputs from the road surface, especially on coarse or uneven terrain. Occasionally, these inputs result in subtle rattle noises that are perceptible only to the driver and may not be detected under controlled testing environments. This poses a challenge for engineers trying to isolate and resolve such intermittent NVH phenomena. Identifying the source requires a combination of real-world driving evaluations, structural
Ramesh Chand, Karan KumarGopinathan, HaridossKabdal, Amit
The high-pressure steering hose in a hydraulic steering system carries pressurized hydraulic fluid from the power steering pump to the steering gear (or steering rack). Its main function is to transmit the force generated by the pump so that the hydraulic pressure assists the driver in turning the wheels more easily. The high-pressure hydraulic pipeline in the power steering system is a vital component for ensuring optimal performance. During warranty analysis, leakage incidents were observed at the customer end within the warranty period. The primary factors contributing to these failures include pipe material thickness, material composition, mechanical properties, and engine-induced vibrations. This study investigates fatigue-related failures through detailed material characterization and Computer-Aided Engineering (CAE) based on real world usage road load data collected. The objective is to identify the root causes by examining the influence of varying pipe thickness on fatigue life
Survade, LalitKoulage, Dasharath BaliramBiswas, Kaushik
Road departures remain a major cause of fatal accidents in passenger vehicles, especially on highways, driving the demand for robust and affordable active safety technologies. Conventional Road Departure Mitigation Systems (RDMS) typically depend on camera- or LiDAR-based sensing, which can be cost-prohibitive and challenging to integrate across diverse vehicle platforms. The available RDMS technologies in the market focuses on road departure detection, and lacks the mitigation strategy. Although existing RDMS solutions have enhanced vehicle safety, their dependency on expensive, specialized sensors limits broader adoption, particularly in cost-sensitive market segments. This study introduces a sensor-less, cost-effective RDMS technology which has two parts, detection and mitigation. The technology utilizes existing vehicle sensors accessed through vehicle CAN channels. A decision tree based logic algorithm processes key parameters such as vehicle speed, steering angle, yaw rate, and
Iqbal, ShoaibAdsul, Sourabh
In driving, steering serves as the input mechanism to control the vehicle's direction. The driver adjusts the steering input to guide the vehicle along the desired path. During manoeuvres such as parking or U-turns, the steering wheel is often turned fully from lock to lock and then released. It is expected that the steering wheel quickly returns to its original position. Steering returnability is defined as the ratio of the difference between the steering wheel position at lock to lock and the steering wheel angle after 3 seconds of release, to the steering wheel angle at the lock position, under steady-state cornering conditions at 10 km/h. Industry standards dictate that the steering system should achieve 75% returnability under these conditions within 3 seconds. Achieving proper steering returnability characteristics is a critical aspect of vehicle design. Vehicles equipped with Electric Power-Assisted Steering (EPS) systems can more easily meet returnability targets since the
Singh, Ram Krishnanahire, ManojJAIN, PRIYAVellandi, VikramanSUNDARAM, RAGHUPATHIPaua, Ketan
This article presents a system to incorporate crash risk into navigation routing algorithms, enabling safety-aware path optimization for autonomous and human-driven vehicles alike. Current navigation systems optimize travel time or distance, while our approach adds crash probability as a routing criterion, allowing users to balance efficiency with safety. We transform disparate data sources, including traffic counts, crash reports, and road network data, into standardized risk metrics. Because traffic volume data only exist for a small subset of road segments, we develop a solution to project average daily traffic estimates to an entire road inventory using machine learning, achieving sufficient coverage for practical implementation. The framework computes exposure-normalized crash rates weighted by severity and integrates these metrics into routing cost functions compatible with existing navigation algorithms. The key strength of our solution is its scalability. In addition to the
Skaug, LarsNojoumian, Mehrdad
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
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
Distributed drive steer-by-wire chassis has significant potential for enhancing vehicle dynamics performance, while also presenting great challenges to vehicle dynamics control. To address the coordination among multiple chassis subsystems and the coupled control allocation of longitudinal and lateral tire forces, this paper proposes a centralized control framework based on optimal yaw moment control. By analyzing the impact of longitudinal and lateral tire forces on vehicle yaw moments, a method for allocating longitudinal and lateral forces with maximum yaw moment as the objective is proposed. On this basis, a hierarchical control architecture is designed, including the driver control layer, motion control layer, tire force allocation layer, and actuator execution layer, to achieve centralized domain control of longitudinal and lateral dynamics in distributed drive steer-by-wire chassis. Finally, the proposed centralized controller is validated using offline simulation and real-time
Wu, DongmeiGuo, ChunzhiLiu, ChangshengXia, XinLi, MiaoLiu, Wei
Ensuring the safe and stable operation of autonomous vehicles under extreme driving conditions requires the capability to approach the vehicle’s dynamic limits. Inspired by the adaptability and trial and error learning ability of expert human drivers, this study proposes a Self-Learning Driver Model (SLDM) that integrates trajectory planning and path tracking control. The framework consists of two core modules: In the trajectory planning stage, an iterative trajectory planning method based on vehicle dynamics constraints is employed to generate dynamically feasible limit trajectories while reducing sensitivity to initial conditions; In the control stage, a neural network enhanced nonlinear model predictive controller (NN-NMPC) is designed, which incorporates a self-learning mechanism to continuously update the internal vehicle model using trial-and-error data on top of mechanistic physical constraints, thereby improving predictive accuracy and path-tracking performance. By combining
Zhang, XinjieXu, LongGuo, KonghuiZhuang, YeHu, TiegangMao, JingGangZeng, Qingqiang
The hydraulic steering gear, in the ball & nut configuration, was introduced in series in 1985, commonly encompassing single circuits with only one hydraulic steering. In medium-sized commercial vehicles, the torque (force) required to turn the wheels through direct mechanical connection is approximately 400 Nm when the vehicle is stationary. By using hydraulic steering, the required torque is reduced to about 50 Nm. When the load of the front axle exceeds 6.7 tons, a dual steering gear system can be used, delivering 200% of the total force. Additionally, the dual steering gear system provides a better turning radius, eliminating the need for a steering assist cylinder, thus giving more space for the front wheels to turn. This article will describe the development of a dual gear for a dual steering gear for commercial vehicles. Schematic diagrams of a dual steering gear and how the system can deliver the required output torque for the steering process it will be shown. The system is
Masunaga, Natália SayuriSantos, AntídioSilva, EvertonPedroso, HugoDestro, DanielMoura, Márcio
min
Wang, JieYang, YueChen, XinCui, Jiaxing
Objective:Methods:Results:Conclusion:
Sun, KeWan, QianLiu, QianqianLi, Qiuling
In order to reduce conflicts between vehicles at intersections and improve safety, an optimization model of traffic sequence allocation is studied and established for the heterogeneous traffic scenario of connected autonomous vehicles and manual vehicles. With the minimum safe traffic time as constraint, the right of way is allocated to vehicles according to the microscopic traffic characteristics of heterogeneous traffic flow fleet movement and the phase of signal lights, and the optimal trajectory planning control of each vehicle and evaluation indicators are established. A jointly simulation running environment is built using VISSIM and MATLAB. The simulation results indicate that at the micro level, collaborative control slows down the waiting time for manually driven vehicles and improves the utilization of green light travel time. At the macro level, as the penetration rate of connected autonomous vehicles increases, the sum of squares of vehicle acceleration gradually decreases
Yuan, ShoutongLi, ZhiqiangLiu, TianyuYu, Zhengyang
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