Browse Topic: Slip

Items (755)

A Steering Control Method Applicable to an Eight-Wheeled Planetary Laboratory

2025-01-8305

04/01/2025

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, Jun, Zhang, Kaidi, Shi, Junwei, Yang, Wenmiao, Zhang, Yunqing, Wu, Jinglai

A Method for Calculation Flow Resistivity of Kapok Fiber Felt

2025-01-8246

04/01/2025

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, Jiaman, Kang, Yingzi, Xie, Xinxing, Zhang, Qu, Yang, Shanmiao, Shangguan, Wen-Bin

Dynamics Analysis and Stability Control of a Lunar Unicycle Self-Balancing Robot

2025-01-8301

04/01/2025

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, Junwei, Zhang, Kaidi, Duan, Yupeng, Wu, Jinglai, Zhang, Yunqing

A Drive Anti-Slip and Lateral Stability Control Technique for Distributed Three-Axis Drive Vehicle

2025-01-8303

04/01/2025

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, Ruiteng, Zheng, Hongyu, Kaku, Chuyo, Zong, Changfu

A Collision Risk Assessment-Based Longitudinal Collision Avoidance Control Strategy for Tractor Semi-Trailers with Slip Ratio Control

2025-01-8037

04/01/2025

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, Yang, Zheng, Hongyu, Zhang, Yuzhou

Estimation of Tire Longitudinal Force under Combined Slip Condition Using an Intelligent Tire System

2025-01-8275

04/01/2025

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, Zipeng, Xu, Nan, Tang, Zepeng, Chen, Hong

Cost-Effective Sideslip Measurement: Beta for the People!

2025-01-8796

04/01/2025

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, Andrew, Compere, Marc

A Torque Distribution Strategy for the Six-Wheeled Lunar Rover

2025-01-8308

04/01/2025

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, Pengcheng, Zhang, Kaidi, Shi, Junwei, Yang, Wenmiao, Zhang, Yunqing, Wu, Jinglai

YRSRA: Yaw and Roll Stable Region Analytics for Ground Vehicle System with 5G-V2X

2025-01-8799

04/01/2025

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, Lihong, Zeng, Dequan, Zhang, Zhouping, He, Qixiao, Zhao, Shuqi, Sun, Jing, Wang, Aichun, Yu, Qin, Ming, Jinghong, Wang, Xiaoliang, Hu, Yiming

Stability Control for Distributed Drive Electric Vehicles Using Particle Filter and Fuzzy Integral Sliding Mode Control

2025-01-8811

04/01/2025

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, Xiaolong, Zheng, Hongyu, Kaku, Chuyo

Driving Force Control for Water-to-Land Transition of Distributed Drive Amphibious Vehicles

2025-01-5011

03/04/2025

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, Bin, Yuan, Zineng, Yu, Wenbin

Nonlinear Joint Dynamic Estimator of Sideslip Angle and Tire-Road Peak Adhesion Coefficient Based on Improved Brush Tire Model

2024-01-7033

12/13/2024

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, Wenrui, Leng, Bo, Han, Yinfeng, Yu, Zhuoping, Xiong, Lu

Influence of Discrete Load Cases on Optimization of Chain Guide Design of Crawler Dozers under Various Ground Conditions

2024-28-0270

12/05/2024

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, Nishant, Bhosale, Dhanaji, Sarma, Neelam K

An Analytical Method to Study Control Strategy of Torque-Vectoring Transmissions for Electric Vehicles Using MATLAB Simulink

2024-28-0210

12/05/2024

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 Raj, Baheti, Palash

Integrated Control of Intelligent Vehicle Driving Stability Using Three-Dimensional Phase Space

10-09-01-0002

10/16/2024

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, Fei, Xiao, Hao, Huang, Chaoqun

Research on Acceleration Slip Regulation for Battery Electric Vehicle

2024-01-3051

09/08/2024

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, Kailei, Liu, Xingchen, Liu, XinHong

A Novel Torque Distribution Approach of Four-Wheel Independent-Drive Electric Vehicles for Improving Handling and Energy Efficiency

2024-01-2315

04/09/2024

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, Jingyang, Chen, Zixuan, Zhang, Yunqing, Wu, Jinglai

On the Investigation of Car Steady-State Cornering Equilibria and Drifting

2024-01-2764

04/09/2024

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, Giovanni, Binetti, Elisabetta, Pinto de Castro, Ricardo, Lot, Roberto, Massaro, Matteo, Lenzo, Basilio

Dynamic Yaw Rate Regulation for Moderate Understeer in Four-Wheel Steering Vehicles with Zero Sideslip Angle

2024-01-2516

04/09/2024

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, Yihang, Zhou, Hongliang, Jing, Houhua, Miao, Weiwei

Experimental Study on Engine Performance Fueled with Ammonia-Hydrogen Blend Ignited by Diesel Pilot

2024-01-2365

04/09/2024

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 Saad, Cheng, Qiang, Yeganeh, Maryam, Kaario, Ossi, Larmi, Martti

Tyre Slip Ratio Estimation Using Intelligent Tyre Concept

2024-01-2299

04/09/2024

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, Bo, Gu, TianLi, Bei, Shaoyi, Guo, Jinfei, Walid, Daoud, Yi, Aibin, Zhu, Yunhai

A study on estimation of stuck probability in off-road based on AI

2024-01-2866

04/09/2024

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, Junhan, byun, Jijun, Jin, Um, Huh, Kunsoo, Yang, Chanuk

Acceleration Slip Regulation of Amphibious Vehicle Driven by Four Wheel Hub Motor for Landing

2024-01-5018

02/07/2024

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, Bin, Xu, Jialuo, Yuan, Zhijun, Wei, Lexia

Research on the Control Strategy for Handling Stability of Electric Power Steering System with Active Front Wheel Steering Function

10-08-01-0006

02/07/2024

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, JinCheng, Zheng, Zhu’An, Chen, JiaLing

Integrated Four-Wheel Steering and Direct Yaw-Moment Control for Autonomous Collision Avoidance on Curved Road

02-17-01-0007

01/25/2024

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

Analytical Calculation to Optimize Magnetic Planetary Gear Topology to Avoid Auto Slip during Various Torque Requirements for Passenger Car Application

2024-26-0041

01/16/2024

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

Improvement of Traction Force Estimation in Cornering through Neural Network

12-07-02-0015

01/04/2024

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, Raffaele, Strano, Salvatore, Terzo, Mario, Tordela, Ciro

Estimation of Lateral Velocity and Cornering Stiffness in Vehicle Dynamics Based on Multi-Source Information Fusion

10-08-01-0003

01/04/2024

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, Guoying, Yao, Jun, Gao, Zhenhai, Gao, Zheng, Wang, Xinyu, Xu, Nan, Hua , Min

Low-Speed Continuous Slip SAE No. 2 μPVT Procedure

J2964_202311 (Current)

11/15/2023

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

Change of Relative Local Velocity in Pulley Groove at Sliding between Belt and Pulleys for Metal Pushing V-Belt Type CVT

2023-01-1851

10/24/2023

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, Taku, Obunai PhD, Kiyotaka, Okubo, Kazuya

Wall Permeability Estimation in Automotive Particulate Filters

2023-24-0110

08/28/2023

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, Callum, Holtzman, Ran, Benjamin, Stephen, Aleksandrova, Svetlana, Watling, Timothy C., Medina, Humberto

Innovative Tire Modeling Bricks for Large Military Vehicles and their Benefits in Simulation Based Chassis Design

2024-01-4086

08/10/2023

Vehicle chassis design can take great advantage from a virtual design approach, as it helps tackle the complexity of modern machines, bringing benefits in performance, development cost, and lead-time. For specific applications such as construction or defense vehicles, the simulation design chain may lack significant input model bricks due to the physical limitations of existing test equipment which limit their ability to characterize the large components and extreme loading conditions (high loads, large torques, extreme slip angles. etc.). Michelin SIMIX proposes / develops an innovative solution to fill the gap by combining physical real world measured data with virtual measurements, allowing the creation of digital models relevant to the full usage perimeter.

Andrews, Mike, Maclanders, Justin, Khayat, Cédric, Leymin, Frédéric, Spetler, Frédéric

A Mid-fidelity Model in the Loop Feasibility Study for Implementation of Regenerative Antilock Braking System in Electric Vehicles

10-07-03-0022

07/29/2023

The tailpipe zero-emission legislation has pushed the automotive industry toward more electrification. Regenerative braking is the capability of electric machines to provide brake torque. So far, the regenerative braking feature is primarily considered due to its effect on energy efficiency. However, using individual e-machines for each wheel makes it possible to apply the antilock braking function due to the fast torque-tracking characteristics of permanent magnet synchronous motors (PMSM). Due to its considerable cost reduction, in this article, a feasibility study is carried out to investigate if the ABS function can be done purely through regenerative braking using a mid-fidelity model-based approach. An uni-tire model of the vehicle with a surface-mount PMSM (SPMSM) model is used to verify the idea. The proposed ABS control system has a hierarchical structure containing a high-level longitudinal slip controller and a low-level SPMSM torque controller. Given the uncertainties of

Ghanami, Nastaran, Nikzadfar, Kamyar, Mohammadi Daniali, Hamid Reza

Design of a Model-Based Optimal Multivariable Control for the Individual Wheel Slip of a Two-Track Vehicle

2023-01-1219

06/26/2023

The concept of autonomous driving has gained increasing relevance, leading to a need for the development of innovative drive concepts for motor vehicles. Therefore, this paper presents a model-based optimal multivariable control for the wheel slip, which allows specifying the wheel slip and thus the tire force individually for each wheel. The plant model consists of a multibody two-track model of a vehicle, a tire model, an air resistance model and a motor model. In addition, the contact forces of the individual wheels are calculated dynamically. The resulting nonlinear model is linearized and used for the design of a linear optimal static state space controller with reference and disturbance feedforward. The contact point velocities at the wheels are defined as the controlled variables, since they are proportional to the wheel slip and thus to the driving forces within the operating range of the controller. In addition, the rates of change of the contact point velocities are also

Irmer, Marcus, Rosenthal, Robert, Nüßgen, Alexander, Degen, René, Thomas PhD, Karin, Ruschitzka PhD, Margot

Investigation of the Influence of Aero-Thermal Non-equilibrium Conditions of an SLD Cloud on Airfoil Icing

2023-01-1406

06/15/2023

This study examines the impact of slip in aero-thermal conditions of supercooled large droplets (SLD) produced in an Icing Wind Tunnel (IWT) on the ice accretion characteristics. The study identifies potential biases in the SLD model development based on IWT data and numerical predictions that assume the SLD to be in aerothermal equilibrium with the IWT airflow. To obtain realistic temperature and velocity data for each droplet size class in the test section of the Braunschweig Icing Wind Tunnel (BIWT), a Lagrangian droplet tracking solver was used within a Monte Carlo framework. Results showed that SLDs experience considerable slips in velocity and temperature due to their higher inertia and short residence time in the Braunschweig IWT. Large droplets were found to be warmer and slower than the flow in the test section, with larger droplets experiencing larger aerothermal slips. To examine the impact of these slips, numerical ice accretion simulations were performed on a NACA 0012

Bora, Venkateshwar Reddy, Gallia, Mariachiara, Knop, Inken, Guardone, Alberto

The Integrated Trajectory Tracking, Yaw Stability and Roll Stability Model Predictive Control for Autonomous Vehicle in Limited Handling Condition

2023-01-0667

04/11/2023

In the current literature, the research studies on the trajectory tracking control and stability control strategy for autonomous vehicles in limited condition mostly focus on the yaw plane control, but few of the studies have considered the combined control performance of trajectory tracking, yaw and roll stability, and the roll stability is critical under the extreme cornering condition for autonomous vehicles. Aiming at the above shortages, this study designs the model predictive control (MPC) strategy for the autonomous vehicles under the limited handling condition, which integrates the front and rear wheel active steering control, four-wheel independent drive and braking control and active suspension control to comprehensively improve the trajectory tracking accuracy, yaw plane stability and roll plane stability of the vehicle under the extreme condition. In the internal prediction model of the MPC, the yaw plane dynamics, roll plane dynamics and suspension system models are

Li, Boyuan, Li, Wenfei, Hua, Wei, Velenis, Efstathios

Study on the Torque Distribution of Wheel-Track Hybrid Drive Vehicles during Pass Shoreline

2023-01-0784

04/11/2023

To study the torque distribution of track and tire in the wheel-track hybrid drive vehicle driving along the shoreline, an analysis model of wheel-track hybrid drive vehicle was established by using multi-body dynamics (MBD), discrete element (DEM), and shoreline pavement construction methods. The vehicle speed, acceleration, torque, vertical load, sinkage, slip, and other indicators when the vehicle passes the shoal at different wheel speed of rotation are analyzed. The relationships between wheel speed of rotation and slip, sinkage and slip, and vertical load and driving moment were studied, and the laws that the sinkage of tires and tracks is positively related to their slippage and the driving moment of wheels and tracks is positively related to their vertical load were obtained. The results show that: (1) The wheel-track hybrid vehicle can pass the specific shoal with subsidence of 330mm~350mm, and the ideal speed is about 5km/h~6km/h, which can be used to improve the shoal

Li, Dengbo, Liu, Hua, Zhang, Kaidi, Zhang, Yunqing

Real-Time Transfer Case 4WD Control Development to Improve Vehicle Coasting Stability

2023-01-0909

04/11/2023

The real-time transfer case installed on the four-wheel drive vehicle with a longitudinally mounted engine, can distribute not only the engine drive torque, but also the engine drag torque between the front and rear axles, to improve vehicle traction and stability performance. When under vehicle coasting condition, the engine drag torque may cause vehicle rear wheel slippage on low friction adhesion road, which causes a vehicle to be unstable and spin in. Although the current engine Drag Torque Control technology has the ability to reduce rear wheel longitudinal slippage by engine torque control, but the control effect is poor, the wheel slip ratio is large and the slipping duration is long, the vehicle still has the tendency to spin in. This paper proposed a new transfer case coasting control strategy to avoid this problem. Through the pre-load control based on vehicle coasting characteristics and closed-loop feedback control based on rear axle slip state, the rapid dynamic

Liu, Yuanzhi, Cui, Jinlong, Xu, Zhan, Zhang, Qiang, Hui, Zhouze, Zhao, Yang, Liu, Xing, Li, Jing, Hong, Jiang, Yuanjun, Lu

Test Results of Tires for All-Terrain Vehicles from a Flat-Trac® Machine

2023-01-0671

04/11/2023

This paper presents tire data from an All-Terrain Vehicle (ATV). Data is collected on a Flat-Trac® machine where force and moment data were collected for three tires: one front tire and two rear tires. Tests were conducted at slip angles of +/-28 degrees, varying normal loads and inclinations angles. Additionally, tests were conducted at varying levels of inflation pressure. Key parametric data such as aligning moment, cornering and vertical stiffness levels are presented. One key finding from this study is that, in general, as inflation pressure increases cornering and aligning moment stiffness decreases. This effect is counter to typical passenger vehicle tires, where higher inflation pressure usually results in higher stiffness levels. Using results from the tire test data, understeer calculations are made for a vehicle under varying loading conditions.

Zagorski, Scott, Heydinger, Gary

Estimation of Tire-road Friction Limit with Low Lateral Excitation Requirement Using Intelligent Tire

2023-01-0755

04/11/2023

Tire-road friction condition is crucial to the safety of vehicle driving. The emergence of autonomous driving makes it more important to estimate the friction limit accurately and at the lowest possible excitation. In this paper, an early detection method of tire-road friction coefficient based on pneumatic trail under cornering conditions is proposed using an intelligent tire system. The previously developed intelligent tire system is based on a triaxial accelerometer mounted on the inner liner of the tire tread. The friction estimation scheme utilizes the highly sensitive nature of the pneumatic trail to the friction coefficient even in the linear region and its approximately linear relationship with the excitation level. An indicator referred as slip degree indicating the utilization of the road friction is proposed using the information of pneumatic trail, and it is used to decide whether the excitation is sufficient to adopt the friction coefficient estimate. The friction

Xu, Nan, Zhou, Jianfeng, Tang, Zepeng, Zhang, Zeyang

Impact of Second NH ₃ Storage Site on SCR NO _x Conversion in an Ultra-Low NO _x Aftertreatment System

2023-01-0367

04/11/2023

Typical two-site storage-based SCR plant models in literature consider NH3 stored in the first site to participate in NH3 storage, NOx conversion and second site to only participate in NH3 storage passively. This paper focuses on quantifying the impact of stored NH3 in the second site on the overall NOx conversion for an ultra-low NOx system due to intra site NH3 mass transfer. Accounting for this intra site mass transfer leads to better prediction of SCR out NH3 thus ensuring compliance with NH3 coverage targets and improved dosing characteristics of the controller that is critical to achieving ultra-low NOx standard. The stored NH3 in the second site undergoes mass transfer to the first site during temperature ramps encountered in a transient cycle that leads to increased NOx conversion in conditions where the dosing is switched off. The resultant NH3 coverage fraction prediction is critical in dosing control of SCR. This phenomenon is evaluated and quantified with different aging

Chundru, Venkata Rajesh, Desai, Chintan, Kadam, Vaibhav, Vernham, Bruce, Sharp, Christopher, Rengarajan, Sankar, Rao, Sandesh, Sarlashkar, Jayant

Laboratory sulfation of an ammonia slip catalyst with a real-world SO ₂ concentration

2023-01-0380

04/11/2023

Upcoming, stricter diesel exhaust emissions standards will likely require aftertreatment architectures with multiple diesel exhaust fluid (DEF) introduction locations. Managing NH3 slip with technologies such as an ammonia slip catalyst (ASC) will continue to be critical in these future aftertreatment systems. In this study, we evaluate the impact of SO2 exposure on a state-of-the-art commercially available ASC. SO2 is co-fed at 0.5 or 3 ppmv to either approximate or accelerate a real-world exhaust SO2 impact. ASC performance during sulfur co-feeding is measured under a wide variety of simulated real-world conditions. Results indicate that the loss of NO conversion during SCR is dependent on the cumulative SO2 exposure, regardless of the inlet SO2 concentration. Meanwhile, N2O formation under SCR conditions is nonlinearly affected by SO2 exposure, with formation increasing during 0.5 ppmv SO2 exposure but decreasing in the presence of 3 ppmv SO2. TPO experiments reveal the formation of

Ottinger, Nathan, Xi, Yuanzhou, Kiani, Daniyal, Liu, Z. Gerald

The Development of a Zeolite-Based Cold-Start Catalyst (CSC) for a Conventional China 6b Vehicle in Meeting the Next More Stringent Chinese Vehicle Emission Standards

2023-01-0233

04/11/2023

A state of art Pd-zeolite based cold-start catalyst (CSC) or HC/NOx trap type of catalyst was codeveloped between Geely Automotive Company and Ningbo Kesen Exhaust Gas Cleaner Manufacturing CO. LTD. This CSC catalyst was added to the downstream of an existing catalyst system (TWC+CGPF) of a China 6b conventional passage car which was powered by a 1.5L turbo charge direct injection (1.5L GTDI) engine. The CSC significantly converted cold-start tailpipe NMHC emission and enabled the tailpipe emissions to meet the engineering targets of the projected next more stringent Chinese vehicle tailpipe emission standards in WLTC cycles. The vehicle tailpipe emission results with the addition of the laboratory simulated 120K km aged CSC also met the projected emission engineering targets of a fresh catalyst. Both the vehicle and laboratory results demonstrated the excellent ammonia adsorption and oxidation function of this CSC catalyst as a very efficient natural ammonia slip catalyst (ASC). Due

Xu, Lifeng, Zhao, Fucheng, Wei, Hong, Zhao, Pengfei, Qian, Wangmu, Qian, Menghan

A Comprehensive Methodology to Design and Develop Suspension System Bolted Joints using Vehicle Test Loads and CAE Simulation

2023-01-0608

04/11/2023

The bolted joints in suspension systems are subjected to severe external service loads during vehicle operation. To prevent the loaded joint from loosening and allowing it to retain its potential energy stored during assembly, a holistic design approach is needed. This paper explains the methodology to design and optimize bolted joints for the suspension systems of a modern 7-seater sports utility vehicle. The optimization technique consists of - 1 Extensive benchmarking of global benchmark vehicles with similar suspension architecture and gross vehicle weights to derive preliminary torque and joint preloads. 2 Measuring external loads acting in x, y and z directions using a wheel force transducer on various durability tracks. 3 Performing Multi body dynamic simulations to obtain the loads at various bolted joint locations. 4 Taking the input of the external loads acting on the individual joints and perform a simulation to evaluate slip at joinery for a given preload. 5 Bolt

Vellandi, Vikraman, Namani, Prasad, Nair, Sharad, Nayak, Bhargav A., Chaudhari, Varun, Patnala, Avinash, Senthil Raja, T., Arunachalam, M

Dynamic Switch Control of Steering Modes for 4WID-4WIS Electric Vehicle Based on MOEA/D Optimization

2023-01-0641

04/11/2023

To overcome the shortcoming that vehicles with multiple steering modes need to switch steering modes at parking or very low speeds, a dynamic switch method of steering modes based on MOEA/D (Multi-objective Evolutionary Algorithm Based on Decomposition) was proposed for 4WID-4WIS (Four Wheel Independent Drive-Four Wheel Independent Steering) electric vehicle, considering the smoothness of dynamic switch, the lateral stability of the vehicle and the energy economy of tires. First of all, the vehicle model of 4WID-4WIS was established, and steering modes were introduced and analyzed. Secondly, the conditions for the dynamic switch of steering modes were designed with the goal of stability and safety. According to different constraints, the control strategy was formulated to obtain the target angle of the active wheels. Then aiming at the smoothness of the dynamic switch, the active wheel angle trajectory was constructed based on the B-spline theory. And the MOEA/D algorithm was used to

Qiao, Yiran, Chen, Xinbo, Li, Ran

Stability Monitoring Algorithm with a Combined Slip Tire Model for Maximized Cornering Speed of High-Speed Autonomous Driving

2023-01-0684

04/11/2023

This paper presents a stability monitoring algorithm with a combined slip tire model for maximized cornering speed of high-speed autonomous driving. It is crucial to utilize the maximum tire force with maintaining a grip driving condition in cornering situations. The model-free cruise controller has been designed to track the desired acceleration. The lateral motion has been regulated by the sliding mode controller formulated with the center of percussion. The controllers are suitable for minimizing the behavior errors. However, the high-level algorithm is necessary to check whether the intended motion is inside of the limit boundaries. In extreme diving conditions, the maximum tire force is limited by physical constraints. A combined slip tire model has been applied to monitor vehicle stability. In previous studies, vehicle stability was evaluated only by vehicle acceleration. The proposed algorithm improves vehicle stability by independently monitoring the saturation point and tire

Kim, Jayu, Park, Jaeyong, Kim, Changhee, Cha, Hyunsoo, Yi, Kyongsu

A Method for Estimating Hysteresis of Automatic Tensioner and Analysis of Hysteresis Variations with Tensioner Parameters

2023-01-0425

04/11/2023

The automatic tensioner is one of the important parts of the front end accessory drive system of the automobile engine. The tensioner uses the relative slip of the friction pair to generate friction torque, which makes its own system have hysteresis characteristics, so that it can automatically control the tension of the belt in the attachment system and improve the NVH performance of the attachment system. This paper takes the automatic tensioner of an engine front end accessory drive system as the research object, and establishes an analytical model and a finite element simulation model for the calculation of the hysteresis characteristics of the tensioner. The hysteresis characteristic test of the tensioner was carried out to verify the correctness of the analytical model and the finite element model, the error between the calculation results and the test results was analyzed, the proportions of the three friction pairs were compared, and the factors affecting the performance of the

Diao, Qiangyou, Wan, Lixiang, Chen, HouChong, Ding, Quanyu, Yan, Yuanqing

Estimation of the Tire-Road Interaction Forces by using Pacejka’s Formulas with Combined Slips and Camber Angles

2023-01-0646

04/11/2023

The growing market demand for highly automated and autonomous vehicles and the need to equip vehicles with ever higher standards of comfort, safety and performance requires knowledge of physical quantities that are often difficult or expensive to measure directly. The absence of direct sensors, the difficulty of implementation, and their cost have led researchers to identify alternative solutions that allow estimating the physical quantity of interest by aggregating other available information. The interaction forces between tire and road are among the most significant. Given that the dynamics of a vehicle are strongly linked to the forces exchanged between the tire and the road, their knowledge is fundamental in the development of control systems aimed at improving performance in terms of handling, road holding or comfort. This paper presents a new technique for the estimation of tire-road interaction forces based on the integration of models and measures. A Central Difference Kalman

Marotta, Raffaele, Ivanov, Valentin, Strano, Salvatore, Terzo, Mario, Tordela, Ciro

The Influence of the Material Construction of Leatherette in Squeak Noise Control

2023-01-0075

04/11/2023

PVC (polyvinylchloride) synthetic leather or called leatherette is being widely used for automotive interior applications for seat cover, gear boot, gap hider, steering wheel and roof liner due to their leather like feel and texture, flexibility, sewability, affordability, and wide design freedom. However, the leatherette construction such as top coating, backing fabric and fabric weaving pattern plays a critical role in the finished leatherette performance for the specific application. This study provides the influence of different coating material and different backing fabric in squeak behavior of gear boot PVC leatherette. The squeak behavior was studied by stick slip test as per automotive engineering requirements, and the response of these coating and fabric surface was measured in the form of Risk Priority Number (RPN).

Palaniappan, Elavarasan, Mohammed, Riyazuddin, Lewis, Edlin, Balaji, K V

EDITORIAL: Autonomous trucking hits rocky road

23TOFHP04_09

04/01/2023

Within a four-week stretch - from roughly mid-February to mid-March - a steady stream of autonomous-trucking news hit. A quick summary: As several startups in the autonomous-truck development space struggle financially, established OEMs keep trucking with acquisitions and partnerships to bolster their automated-driving capabilities. On March 3, the cofounder and CEO of Embark Trucks, which was founded in 2016, sent an email to all its employees announcing the company's likely imminent closure. “The last nine months have been tough for the autonomous trucking industry, and for Embark - the capital markets have turned their backs on pre-revenue companies, just as slipping manufacturer timelines have delayed the prospect of scaled commercial deployment,” Alex Rodrigues wrote.

Gehm, Ryan

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