Browse Topic: Vehicle acceleration

Items (2,374)
Hydro-pneumatic suspension is widely used due to its favorable nonlinear stiffness and damping characteristics. However, with the presence of parameter uncertainties and high nonlinearities in the hydro-pneumatic suspension system, the effectiveness of the controller is often suboptimal in practical applications. To mitigate the influence of these issues on the control performance, an adaptive sliding mode control method with an expanded state observer (ESO) is proposed. Firstly, a nonlinear mathematical model of hydro-pneumatic suspension, considering seal friction, is established based on the hydraulic principle and the knowledge of fluid mechanics. Secondly, the ESO is designed to estimate the total disturbance caused by the nonlinearities and uncertainties, and it is incorporated into the sliding mode control law, allowing the control law to adapt to the operating state of the suspension system in real time, which solves the effect of uncertainties and nonlinearities on the system
Niu, ChangshengLiu, XiaoangJia, XingGong, BoXu, Bo
In this paper, the equivalent elliptic gauge pendulum model of liquid sloshing in tank is established, the pendulum dynamic equation of tank in non-inertial frame of reference is derived, and the dynamics model of tank transporter is constructed by force analysis of the whole vehicle. A liquid tank car model was built in TruckSim to study its dynamic response characteristics. Aiming at the problem that the coupling effect between liquid sloshiness in tank and tank car can easily affect the rolling stability of vehicle, the roll dynamics model of tank heavy vehicle is established based on the parameterized equivalent elliptic gauge single pendulum model, and the influence of different lateral acceleration and suspension system on the roll stability is studied. The results show that the coupling effect between the motion state of the tank car and the liquid slosh lengthens the oscillation period of the liquid slosh in the tank, and the amplitude of the load transfer rate of the tank car
Yukang, Guo
Two wheelers motorcycles are used for many purposes e.g. commuting from one place to another, long highway rides, racing and off-roading. Motorcycles which are used in off-road conditions require higher suspension strokes to absorb large oscillations due to terrain conditions. These motorcycles undergo jumps of varying heights and different vehicle orientations. In some of the dynamic situations front wheel may land on the ground before the rear and in other cases it may be vice versa. To make sure that the vehicle is durable enough to withstand loads in such operating conditions, vehicle drop test was developed in test lab where vehicle is dropped from predefined heights in both front & rear wheel landing conditions. Same test case is simulated in multibody dynamics to capture loads at important connections of the frame. This paper presents the correlation exercise carried out to validate MBD model and simulation process with test data captured during lab test. Accelerations at
Jain, Arvind KumarNirala, Deepak
Fatigue design is invariably of prior concern for the automotive industry, no matter of the evolution of the mobility market: at first because carmakers must stay compliant with general structural integrity requirements for reliability, notably applicable to the chassis system, then due to the endless competition for lightweighting in order to mitigate product costs and/or enhance vehicle efficiency. In the past, this key performance was often tackled by basic reference load cases, making use of the simplest signal content, e.g. sinus functions, to practice constant amplitude loads on test rigs and for computations, respectively. Nowadays, full time series coming from proving ground measurements, or any corresponding virtual road load data computations, may be applied to feed complex vehicle computations for virtual assessment and complex test facilities for final approval, under variable amplitude loads. In between, the concept of load spectra (i.e. distribution of amplitudes with
Facchinetti, Matteo LucaTjhung, TanaJaffre lng, SébastienDatta, SandipHayat lng, RomainGuo, Mingchao
To address the issue of high accident rates in road traffic due to dangerous driving behaviors, this paper proposes a recognition algorithm for dangerous driving behaviors based on Long Short-Term Memory (LSTM) networks. Compared with traditional methods, this algorithm innovatively integrates high-frequency trajectory data, historical accident data, weather data, and features of the road network to accurately extract key temporal features that influence driving behavior. By modeling the behavioral data of high-accident-prone road sections, a comprehensive risk factor is consistent with historical accident-related driving conditions, and assess risks of current driving state. The study indicates that the model, in the conditions of movement track, weather, road network and conditions with other features, can accurately predict the consistent driving states in current and historical with accidents, to achieve an accuracy rate of 85% and F1 score of 0.82. It means the model can
Huang, YinuoZhang, MiaomiaoXue, MingJin, Xin
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 cost- effective P2 hybrid vehicles with low voltage electric machines connected to the engine, an interesting control problem arises during the transition to a locked driveline state. This occurs when the engine connects to the wheels via a separation clutch. The two primary torque sources, the engine and the clutch, are traditionally imperfect estimators of applied and transferred torques. The Hybrid Supervisor’s feedforward constraints model relies on these imperfect inputs to determine torque and acceleration limits for the engine’s desired acceleration profiles and to specify engine feedforward commands, aiming for synchronization speed. Due to the inaccuracies in the torque estimates of the engine and clutch, the Hybrid Supervisor is susceptible to control windup, increased jerk to the driveline during synchronization, and inaccurate computation of its target acceleration profile, speed, and torque targets for the engine to achieve synchronization speed. This paper presents a
Banuso, AbdulquadriSha, HangxingKarogal, IndrasenMadireddy, Krishna ChaitanyaPatel, Nadirsh
The paper provides a detailed analysis of the transmission system design under the single motor drive scheme, with a focus on the 2024 Formula SAE (FSAE). The selection of the motor type is determined based on race rules and battery box output power limits. In terms of transmission ratio design, this study takes into account the car's power, balancing acceleration ability and maximum speed to determine an optimal transmission ratio through theoretical calculations and empirical values. Furthermore, it explores how to optimize overall drive system performance by considering technical parameters, power requirements, economic considerations of each system assembly, and validates these findings through software simulations. Notably, significant improvements in reliability are achieved with the newly designed transmission system and wheel rim system while also proposing lightweighting methods for key components. We have carried out extensive verification in both simulation and real vehicle
Wang, LiuxinLi, ChengfengZhu, XiranLiu, Minmin
The motor controller, as one of the important controllers in the electric drive system, may cause unexpected acceleration or deceleration of the vehicle by the driver due to systematic failure and random hardware failure. Conducting research on the functional safety of drive motors for new energy vehicles is of great significance for reducing the systematic failure and random hardware failure of the electric drive. This paper has carried out designs including the allowable motor torque design for safety monitoring, the motor torque prediction design for safety monitoring, the rationality judgment design of the motor torque for safety monitoring, the rationality judgment design of the motor direction for safety monitoring, the functional safety motor degradation design, and the active discharge state monitoring of the motor, so that the system can transition to a safe state when an error occurs. Among them, the motor torque prediction design for safety monitoring includes predicting the
Jing, JunchaoZuo, BotaoLiu, YiqiangHuang, WeishanDai, Zhengxing
Abstract Real-world driving data is an invaluable asset for several types of transportation research, including emissions estimation, vehicle control development, and public infrastructure planning. Traditional methods of real-world driving data collection use expensive GPS-based data logging equipment which provide advanced capabilities but may increase complexity, cost, and setup time. This paper focuses on using the Google Maps application available for smartphones due to the potential to scale-up real-world driving data logging. Samples of the potential data processing and information that can be gathered by such a logging methodology is presented. Specifically, two months of Google Maps driving data logged by a rural Michigan resident on their smartphone may provide insights on their driving range, duration, and geographic area of coverage (AOC) to guide them on future vehicle purchase decisions. Aggregating such statistics from crowd-sourcing real-world driving data via Google
Manoj, AshwinYin, SallyAhmed, OmarVaishnav, ParthStefanopoulou, AnnaTomkins, Sabina
Electrified powertrains, including Power Splits (Electrically Variable Transmissions), Range Extenders (Series Hybrids), and Electric Vehicles with Disconnect Actuators, offer significant flexibility in managing input actuator acceleration and output torque, drawing power from shared sources. The Hybrid Supervisory Controller (HSC) plays a crucial role in balancing these parameters to meet performance and drivability metrics, yet it often faces challenges under power constraints or sudden high output demands, which can lead to imbalanced control, reduced actuator performance, and unintended vehicle motion. Traditional solutions have typically prioritized one control objective over others, compromising overall system performance. This paper introduces an advanced control strategy that optimally distributes control efforts across multiple actuators with overlapping and conflicting objectives. By resolving these conflicts, the proposed approach ensures system stability and enhances
Madireddy, Krishna ChaitanyaBanuso, AbdulquadriPatel, NadirshSha, HangxingKhanal, Shishir
Model-Based Systems Engineering (MBSE) enables requirements, design, analysis, verification, and validation associated with the development of complex systems. Obtaining data for such systems is dependent on multiple stakeholders and has issues related to communication, data loss, accuracy, and traceability which results in time delays. This paper presents the development of a new process for requirement verification by connecting System Architecture Model (SAM) with multi-fidelity, multi-disciplinary analytical models. Stakeholders can explore design alternatives at a conceptual stage, validate performance, refine system models, and take better informed decisions. The use-case of connecting system requirements to engineering analysis is implemented through ANSYS ModelCenter which integrates MBSE tool CAMEO with simulation tools Motor-CAD and Twin Builder. This automated workflow translates requirements to engineering simulations, captures output and performs validations. System
Upase, BalasahebShroff, Roopesh
This study is to demonstrate a vehicle dynamics simulation process to assess vehicle vibration performance. A vehicle dynamics model including non-linear tuning elements and flexible vehicle body is simulated on ride roads. The goal of the simulation is acceleration responses at the passenger locations in frequency domain. Body interface loads are recovered from the vehicle dynamic simulations. Frequency response function (FRF) of the body structure is ready in a fashion that input forces are applied to all body interface locations to the suspension and powertrains. This will give acceleration response sensitivity of the body structure to each body interface. The sum of body interface loads multiplied by FRF at each interface produces acceleration responses in frequency domain. A mid-size sedan model was used to demonstrate the process. A full vehicle dynamics model using Ansys Motion was simulated on a virtual ride road at a constant speed. The body loads were recovered in time domain
Hong, Hyung-JooMaddula, Pavan KumarJun, Hyochan
Drivers present diverse landscapes with their distinct personalities, preferences, and driving habits influenced by many factors. Though drivers' behavior is highly variable, they can exhibit clear patterns that make sorting them into one category or another possible. Discrete segmentation provides an effective way to categorize and address the differences in driving style. The segmentation approach offers many benefits, including simplification, measurement, proven methodology, customization, and safety. Numerous studies have investigated driving style classification using real-world vehicle data. These studies employed various methods to identify and categorize distinct driving patterns, including naturalist differences in driving and field operational tests. This paper presents a novel hybrid approach for segmenting driver behavior based on their driving patterns. We leverage vehicle acceleration data to create granular driver segments by combining event and trip-based methodologies
Chavan, Shakti PradeepChinnam, Ratna Babu
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
Videos from cameras onboard a moving vehicle are increasingly available to collision reconstructionists. The goal of this study was to evaluate the accuracy of speeds, decelerations, and brake onset times calculated from onboard dash cameras (“dashcams”) using a match-moving technique. We equipped a single test vehicle with 5 commercially available dashcams, a 5th wheel, and a brake pedal switch to synchronize the cameras and 5th wheel. The 5th wheel data served as the reference for the vehicle kinematics. We conducted 9 tests involving a constant-speed approach (mean ± standard deviation = 57.6 ± 2.0 km/h) followed by hard braking (0.989 g ± 0.021 g). For each camera and brake test, we extracted the video and calculated the camera’s position in each frame using SynthEyes, a 3D motion tracking and video analysis program. Scale and location for the analyses were based on a 3D laser scan of the test site. From each camera’s position data, we calculated its speed before braking and its
Flynn, ThomasAhrens, MatthewYoung, ColeSiegmund, Gunter P.
Accurate reconstruction of vehicle collisions is essential for understanding incident dynamics and informing safety improvements. Traditionally, vehicle speed from dashcam footage has been approximated by estimating the time duration and distance traveled as the vehicle passes between reference objects. This method limits the resolution of the speed profile to an average speed over given intervals and reduces the ability to determine moments of acceleration or deceleration. A more detailed speed profile can be calculated by solving for the vehicle’s position in each video frame; however, this method is time-consuming and can introduce spatial and temporal error and is often constrained by the availability of external trackable features in the surrounding environment. Motion tracking software, widely used in the visual effects industry to track camera positions, has been adopted by some collision reconstructionists for determining vehicle speed from video. This study examines the
Perera, NishanGriffiths, HarrisonPrentice, Greg
Sled crash tests are an important tool to develop automotive restraint systems. Compared with full-scale crash tests, the sled test has a shorter development cycle of the restraint system and lower cost. The objective of the present study is to create a cost-effective sled test methodology, calculate the optimal static yaw angle and loading curves, and analyze the motion response and injuries of the dummy in the small overlap crash test. The effectiveness of the proposed methodology was verified under two typical small overlap frontal crash modes: “energy-absorption” and “sideswipe”. The results show that with the calculated yaw angle α, the HIC was different from the small overlap crash model, but all remaining indices were within 5% of the injury criteria. All International Organization for Standardization (ISO) values between the combined accelerations of all parts of the dummy and those of the basic model exceeded 0.75, and some values were above 0.8. Therefore, the proposed sled
Yu, LiuChen, JianzhuoWan, Ming XinFan, TiqiangYang, PeilongNie, ZhenlongRen, LihaiCheng, James Chih
Hybrid vehicles are driven by the vehicle controller, engine controller and motor controller through torque control, and there may be unexpected acceleration or deceleration of the vehicle beyond the driver's expectation due to systematic failure and random hardware failure. Based on the torque control strategy of hybrid vehicles, the safety monitoring model design of torque control is carried out according to the ISO 26262 safety analysis method. Through the establishment of safety goals and the analysis of safety concepts, this paper conducts designs including the driver allowable torque design for safety monitoring, the driver torque prediction design for safety monitoring, the rationality judgment design of driver torque for safety monitoring, the functional safety degradation design, and the engine start-stop status monitoring, enabling the system to transition to a safe state when errors occur. Firstly, the design of the driver's allowable torque includes the allowable requested
Jing, JunchaoWang, RuiguangLiu, YiqiangHuang, WeishanDai, Zhengxing
Amphibious vehicles are widely used in civil and military scenarios due to their excellent driving performance in water and on land, unique application scenarios and rapid response capabilities. In the field of civil rescue, the hydrodynamic performance of amphibious vehicles directly affects the speed and accuracy of rescue, and is also related to the life safety of rescuers. In the existing research on the hydrodynamic performance of amphibious vehicles, seakeeping performance has always been the focus of research by researchers and amphibious vehicle manufacturers, but most of the existing research focuses on the navigation performance of amphibious vehicles in still water. In actual application scenarios, amphibious vehicles often face complex water conditions when performing emergency rescue tasks, so it is very important to study the navigation performance of amphibious vehicles in waves. Aiming at the goal of studying the navigation performance of amphibious vehicles in waves
Zhang, Yu
This paper explores a parameter optimization calculation method for a dual-motor coupled integrated single-axle drive system, aiming to achieve the optimal balance between vehicle dynamics, fuel efficiency, and system efficiency under this configuration. By constructing a vehicle longitudinal dynamics model and referencing motor models, the effective operating range is calculated. Vehicle acceleration time, gradeability, and maximum speed are used as constraints, while the proportion of the high-efficiency operating area of the drive system is taken as the objective function for optimizing relevant system parameters. This method improves computational efficiency by dividing the contour lines, thus eliminating the need to traverse all points in the constraint area and converting them into an intuitive analysis of the operating range, which reduces the need for point-by-point calculations across the entire working area.
Gu, ZhuangzhuangYou, JianhuiWu, JinglaiZhang, Yunqing
One challenge for autonomous vehicle (AV) control is the variation in road roughness which can lead to deviations from the intended course or loss of road contact while steering. The aim of this work is to develop a real-time road roughness estimation system using a Bayesian-based calibration routine that takes in axle accelerations from the vehicle and predicts the current road roughness of the terrain. The Bayesian-based calibration method has the advantage of providing posterior distributions and thus giving a quantifiable estimate of the confidence in the prediction that can be used to adjust the control algorithm based on desired risk posture. Within the calibration routine, a Gaussian process model is first used as a surrogate for a simulated half-vehicle model which takes vehicle velocity and road surface roughness (GD) to output the axle acceleration. Then the calibration step takes in the observed axle acceleration and vehicle velocity and calibrates the Gaussian process model
Lewis, EdwinaParameshwaran, AdityaRedmond, LauraWang, Yue
Drivers sometimes operate the accelerator pedal instead of the brake pedal due to driver error, which can potentially result in serious accidents. To address this, the Acceleration Control for Pedal Error (ACPE) system has been developed. This system detects such errors and controls vehicle acceleration to prevent these incidents. The United Nations is already considering regulations for this technology. This ACPE system is designed to operate at low speeds, from vehicle standstill to creep driving. However, if the system can detect errors based on the driver's operation of the accelerator pedal at various driving speeds, the system will be even more effective in terms of safety. The activation threshold of ACPE is designed to detect operational errors, and it is necessary to prevent the system from being activated during operational operations other than operational errors, i.e., false activation. This study focuses on the pedal operation characteristics of pedal stroke speed and
Natsume, HayatoShen, ShuncongHirose, Toshiya
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
Driving speed affects road safety, impacting crash severity and the likelihood of involvement in accidents on highway bridges. However, their impacts remain unclear due to inconsistent topography and consideration of crash types. This study aimed to identify the status of accidents and factors associated with accidents occurring on bridges along the Mugling to Narayanghat highway segment in Nepal. The study area involves the selected highway segment stretching from Aptari junction (CH: 2+42) to Mugling junction (CH: 35+677). Spanning 33.25 km, the road traverses through both hilly and Terai regions. The study employs descriptive and correlation statistics to analyze crash data from 2018 to 2023, aiming to achieve its research objectives. The study reveals overspeeding as the primary cause of crashes, notably head-on and rear-end collisions. Two-wheelers frequently exceed the speed limit of 40 km/h limit (29–88 km/h), and four-wheelers do similarly (18–81 km/h), leading to overspeeding
Giri, Om PrakashShahi, Padma BahadurKunwar, Deepak Bahadur
Highway construction zones present substantial safety challenges due to their dynamic and unpredictable traffic conditions. With the rising number of highway projects, limited accident data during brief construction phases underscores the need for alternative safety evaluation methods, such as traffic conflict analysis. This study addresses vehicular safety issues within the Kunshan section of the Shanghai-Nanjing Expressway, focusing on conflict risk assessment through a spatio-temporal analysis of a construction zone. Using drone-captured video, vehicle trajectories were extracted to derive key operational indicators, including speed and acceleration, providing a spatio-temporal foundation for analyzing traffic flow and conflict dynamics. A novel **Comprehensive Collision Risk Index (CCRI)** was introduced, integrating Time-to-Distance-to-Collision (TDTC) and Enhanced Time-to-Collision (ETTC) metrics to enable a multidimensional assessment of conflict risk. The CCRI captures both
Zhang, YuwenGuo, XiuchengMa, Yuheng
Tunnel linings are an important safeguard for the integrity and stability of tunnels. However, cracks in the tunnel lining may have extremely unfavourable consequences. With the acceleration of urbanisation and the increasing construction of tunnels, the problem of cracks in the concrete lining is becoming more and more prominent. These cracks not only seriously affect the stability of the structure, but also pose a serious threat to the safety of tunnel operation. If left unchecked, the cracks may expand further and cause various safety hazards, such as water leakage and falling blocks. This in turn will undermine the normal function of the tunnel and endanger the lives of tunnel users. It has been proved that the traditional manual method of detecting cracks in tunnels has problems such as low accuracy and low efficiency. In order to solve this problem, it is very necessary for this study to pioneer an intelligent method for identifying tunnel lining cracks using the YOLOv11
Zhang, YalinNiu, PeiGuo, FengYan, WeiLiu, JianKou, Lei
This study presents the development and integration of a vehicle mass estimator into the ZF’s Adaptive Cruise Control (ACC) system. The aim is to improve the accuracy of the ACC system’s torque control for achieving desired speed and acceleration. Accurate mass estimation is critical for optimal control performance, particularly in commercial vehicles with variable loads. The incorporation of such mass estimation algorithm into the ACC system leads to significant reductions in the error between requested and measured acceleration during both flat and uphill driving conditions, with or without a preceding vehicle. The article details the estimator’s development, integration, and validation through comprehensive experimental testing. An electric front-wheel drive van was used. The vehicle’s longitudinal dynamics were modeled using D’Alembert’s principle to develop the mass estimation algorithm. This algorithm updates the mass estimate based on specific conditions: zero brake torque, high
Marotta, RaffaeleD’Itri, ValerioIrilli, AlessandroPeccolo, Marco
With the increase in vehicle population, the environmental problems caused by excessive carbon emissions from vehicles are becoming increasingly serious. Currently, China is actively promoting the development of electric vehicles to reduce carbon emissions. However, the electricity used by electric vehicles is a secondary energy source, and thermal power generation still dominates China's current power structure, so electric vehicles will indirectly contribute to carbon emissions during use. Calculating and analysing the carbon emissions of fuel vehicles and electric vehicles will give a better idea of the environmental advantages of electric vehicles. In this paper, the World Light Vehicle Test Cycle (WLTC) are selected, and the energy consumption is calculated by the energy consumption formula of fuel and electric vehicles under different conditions, and the carbon emission is obtained by the carbon emission coefficients of gasoline and electric energy. Through MATLAB calculation
Xie, HaonanLin, Guangyu
To enhance energy efficiency of series-parallel hybrid system, this paper investigates and compares the effects of adding the gear ratio at different power source position on the performance of the vehicle. Firstly, the effect of adding gears at various positions is analyzed on the basis of intelligent multi-mode drive (IMMD) configuration, and the potential working modes resulting from the added gear ratios at different power source positions are examined. Secondly, multi-objective particle swarm optimization (MOPSO) algorithm is used to optimize the transmission ratio of new gears, laying the groundwork for comparing different configurations. Moreover, the fuel economy performance of the optimized series-parallel configuration was evaluated using a rapid dynamic programming approach with the objective function of minimizing fuel consumption during power transfer. Finally, in accordance with the aforementioned research, the acceleration performance and economic performance of
Zhang, YuxinZou, YungeYang, Yalian
Distributed Drive Electric Vehicles (DDEVs), as a significant development form of electric vehicles, have garnered considerable focus owing to their excellent energy utilization efficiency and the capability for flexible torque distribution. However, DDEVs still face numerous challenges in practical applications, particularly in the coordinated control of hub motors and system stability. This paper focuses on the whole-vehicle control technology and distributed control theory of DDEVs and researches the active safety function of Direct Yaw-moment Control (DYC): acceleration and turning. A full-order terminal sliding mode controller is utilized to suppress the chattering of sliding mode control and to reduce torque fluctuations in the output. Results show that the proposed method can enhance the vehicle’s yaw stability and driving safety with the linear sliding mode.
Zhou, MinghaoWu, WeiweiFei, XueranChen, ZhenqiangJiang, LongbinCai, William
Electrified powertrain configurations are critical to the fuel economy and performance of hybrid vehicles. While single planetary gear (PG) configurations - such as the Toyota Prius - have the advantage of simple control and excellent fuel economy, the generator1 is unable to participate in the drive, resulting in poor acceleration. To overcome these problems, we propose a new multi-gear electronically controlled continuously variable transmission (ECVT) due to its high efficiency and excellent acceleration performance. It requires only one PG and two synchronizers. For this type of multi-gear ECVT hybrid vehicle, this paper describes in detail the synchronizer-based shift logic of the new configuration. Furthermore, the power flow and dynamics modeling process in different operating modes are systematically analyzed. In addition, the global optimal Dynamic Programming (DP) algorithm is presented and a new near-optimal energy management strategy, Rapid-DP, is employed to evaluate the
Zou, YungeZhang, YuxinYang, YalianLiu, Changdong
This study investigates the effects of replacing a 6-speed gearbox with a 5-speed gearbox in a sports vehicle, while keeping all other parameters constant. Through computational simulations, data is collected for comparative performance analysis. The study aims to understand the potential implications of this change on acceleration, fuel efficiency, engine response, as well as aspects such as driver comfort. The results may provide valuable insights for the automotive industry, guiding future transmission design and engineering decisions.
Marinho, Gabriel Jannuzzide Campos, Josué QueirozLopes, Elias Dias RossiRodrigues, Gustavo Simão
The aerodynamic force produced by external flows over two-dimensional bodies is typically decomposed into two components: lift and drag. In race cars, the lift is known as downforce and it is responsible for increasing tire grip, thereby enhancing traction and cornering ability. Drag acts in the direction opposite to the car’s motion, reducing its acceleration and top speed. The primary challenge for aerodynamicists is to design a vehicle capable of producing high downforce with low drag. This study aims to optimize the shape of a multi-element rear wing profile of a Formula 1 car, achieving an optimal configuration under specific prescribed conditions. The scope of this work was limited to a 2-D model of a rear wing composed of two 4-digit NACA airfoils. Ten control parameters were used in the optimization process: three to describe each isolated profile, two to describe their relative position, and two to describe the angles of attack of each profile. An optimization cycle by finite
Souza Dourado, GuilhermeHayashi, Marcelo Tanaka
During accelerations and decelerations of a race car whose engine has a wet sump, the forces generated by the vehicle’s motion cause the engine oil to vigorously shift towards the walls of the oil pan and crankcase, contributing to the phenomenon known as ‘sloshing.’ This phenomenon often leads to fluctuations in oil pressure, resulting in oil pressure surge, when the oil is pushed away from the pump pickup point. Via the logged data, the Formula UFSM FSAE Team had witnessed a recurrent lack of oil pressure in the race track during the 2023 Brazilian FSAE competition. In the AutoCross Event, the recurrence of this problem was 80% of the right corners on lateral accelerations between 0.80G and 1.30G. The average oil pressure in this condition was 0.80 bar, even reaching 0.10 bar above 5000 RPM. Therefore, it was necessary to develop a new set of baffles for the oil pan, capable of minimizing the effects of sloshing and, consequently, the oil surge. As a method of research, a test bench
Zimmermann, Natalia DiovanaJunior, Luiz Alfredo CoelhoMartins, MarioHausen, Roberto
Single lane changing is one of the typical scenarios in vehicle driving. Planning an appropriate lane change trajectory is crucial in autonomous and semi-autonomous vehicle research. Existing polynomial trajectory planning mostly uses cubic or quintic polynomials, neglecting the lateral jerk constraints during lane changes. This study uses seventh-degree polynomials for lane change trajectory planning by considering the vehicle lateral jerk constraints. Simulation results show that the utilization of the seventh-degree method results in a 41% reduction in jerk compared to the fifth-degree polynomial. Furthermore, this study also proposes lane change trajectory schemes that can cater to different driving styles (e.g., safety, efficiency, comfort, and balanced performance). Depending on the driving style, the planned lane change trajectory ensures that the vehicle achieves optimal performance in one or more aspects during the lane change process. For example, with the trajectory that
Lai, FeiHuang, Chaoqun
Hydro-pneumatic suspension is widely used because of its desirable nonlinear stiffness and damping characteristics. However, the presence of parameter uncertainties and high nonlinearities in the system, lead to unsatisfactory control performance of the traditional controller in practical applications. In response to this challenge, this paper proposes a novel stability control method for active hydro-pneumatic suspension (AHPS). Firstly, a nonlinear mathematical model of the hydro-pneumatic suspension, considering the seal friction, is established based on the hydraulic principle and the knowledge of Fluid dynamics. On the basis of the established hydro-pneumatic suspension nonlinear model, a vehicle dynamics model is established. Secondly, an active disturbance rejection sliding mode controller (ADRSMC) is designed for the vertical, roll, and pitch motions of the sprung mass. The lumped disturbance caused by the model nonlinearities and uncertainties is estimated by the extended
Niu, ChangshengLiu, XiaoangJia, XingGong, BoXu, Bo
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
This study proposes a multi-mode switching control strategy based on electromagnetic damper suspension (EMDS) to address the different performance requirements of suspension systems on variable road surfaces. The working modes of EMDS are divided into semi-active damping mode and energy harvest mode, and the proposed mode switching threshold is the weighted root mean square value of acceleration. For the semi-active damping mode, a controller based on LQR(Linear Quadratic Regulator) was designed, and a variable resistance circuit was also designed to meet the requirements of the semi-active mode, which optimized the damping effect relative to passive suspension. For the energy harvest mode, an energy harvest circuit was designed to recover vibration energy. In order to reduce the deterioration of suspension performance caused by frequent mode switching in the mode switching strategy, as frequent system switching can lead to system disorder, deterioration of damping effect, and
Zeng, ShengZhang, BangjiTan, BohuanQin, AnLai, JiewenWang, Shichen
This paper evaluates electric machine and reducer specifications along-side vehicle dynamics and drivability for an axial flux machine (AFM). The baseline is a conventional central drive unit with a single electric machine, reducer, and differential. It compares powertrain architectures with two in-wheel AFMs (IWD) and one AFM mounted perpendicular to the chassis against the E-Axle design. The study starts by determining wheel-level traction force and power requirements for a mid-sized vehicle, then derives necessary machine and reducer specifications. It also considers packaging and efficiency constraints. The E-Axle uses a single-stage planetary gearbox, while the perpendicular AFM connects to a bevel gear reducer, and the IWD requires no reducer. These architectures are analysed in a vehicle dynamics simulation with six degrees of freedom, suspension, tire, and road models. Efficiency is assessed using the Worldwide Harmonized Light Vehicles Test Cycle (WLTC). Besides acceleration
Wipfler, FelixYildirim, MetinNegrila, Andrei-RaduGerling, DieterBruell, MartinSabzewari, Kiarash
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
This research aims to develop an inverse controller to track target vibration signals for the application to car subsystem evaluations. In recent times, perceptive assessments of car vibration have been technically significant, particularly parts interacting with passengers in the car such as steering wheels and seats. Conventional vibration test methods make it hard to track the target vibration signals in an accurate manner without compensating for the influence of the transfer function. Hence, this paper researched the vibration tracking system based on inverse system identification and digital signal processing technologies. Specifically, the controller employed a semi-active algorithm referring to both the offline modeling of the inverse system and the adaptive control. The semi-active controller could reconstruct the target vibration signal in a more efficient and safer way. The proposed methodology was first confirmed through computation simulations using Simulink. The
Jung, GyuYeolLee, Sang KwonAn, KanghyunJang, SunyoungShin, TaejinKwak, WooseongKim, Howuk
Indian Space Research Organisation (ISRO) uses indigenously developed launch vehicles like PSLV, GSLV, LVM3 and SSLV for placing remote sensing and communication satellites along with spacecrafts for other important scientific applications into earth bound orbits. Navigation systems present in the launch vehicle play a pivotal role in achieving the intended orbits for these spacecrafts. During the assembly of these navigation packages on the launch vehicle, it is required to measure the initial tilt of the navigation sensors for any misalignment corrections, which is given as input to the navigation software. A high precision inclinometer is required to measure these tilts with a resolution of 1 arc-second. In this regard, an indigenous inclinometer is being designed. The sensing element of this design comprises of a compliant mechanism which is designed to sense the tilt by measuring the displacement of a proof mass occurring due to the respective component of earth’s gravitational
Shaju, Tony MKrishna, NirmalRao, G NagamalleswaraKumar, T SureshK, Pradeep
This article proposes the structure and algorithm to design a PID controller for the driving wheel slip prevention system (DWSPs) of a dump truck using a diesel engine, which is equipped just only with a traditional high-pressure pump (HPP) under low-adhesion coefficient conditions. First, a longitudinal dynamic model, and a dynamic model of the wheel and powertrain of a dump truck are, respectively, established, and an experiment in the torque determination of a diesel engine is set up to investigate longitudinal vehicle dynamics as well. Then, a control system structure of the DWSPs for a dump truck using a diesel engine with a high-pressure inline fuel pump is proposed. Finally, based on performance analysis of other types of controllers, a PID controller is selected to control actual load level of a diesel engine. The criteria representing the vehicle’s acceleration such as the vehicle speed, vehicle acceleration, total slip time, and time to reach vehicle speed are selected to
Van Thoan, TranVu, Le AnhVan Nguyen, KhongHai, Ho HuuPhuc, Dam HoangKhanh, Duong NgocQuynh, Le Van
This article introduces an innovative method for predicting tire–road interaction forces by exclusively utilizing longitudinal and lateral acceleration measurements. Given that sensors directly measuring these forces are either expensive or challenging to implement in a vehicle, this approach fills a crucial gap by leveraging readily available sensor data. Through the application of a multi-output neural network architecture, the study focuses on simultaneously predicting the longitudinal, lateral, and vertical interaction forces exerted by the rear wheels, specifically those involved in traction. Experimental validation demonstrates the efficacy of the methodology in accurately forecasting tire–road interaction forces. Additionally, a thorough analysis of the input–output relationships elucidates the intricate dynamics characterizing tire–road interactions. This research underscores the potential of neural network models to enhance predictive capabilities in vehicle dynamics, offering
Marotta, RaffaeleStrano,  SalvatoreTerzo, MarioTordela, Ciro
The paper introduces two methods for controlling motor voltage. One method requires the implementation of boost hardware, while the other allows for voltage control in battery failure mode without any additional hardware requirements. The boost voltage strategy for the hybrid system is based on managing boost modes, determining target voltages, and implementing PI control. The boost mode control includes different modes such as initial mode, normal mode, shutdown mode, and fault mode. Determining the boost target voltage involves regulating the boost converter with variable voltages depending on the operating states of the motor and generator. The second voltage control method without boost hardware is proposed in order to ensure that the vehicle can still function like a traditional car even under abnormal conditions of high-voltage battery failure in micro-mixing systems. In this mode, instead of conventional torque control, the generator operates in a voltage control mode where
Jing, JunchaoSun, XudongLiu, YiqiangHuang, Weishan
Brake pulsation is a low frequency vibration phenomenon in brake judder. In this study, a simulation approach has been developed to understand the physics behind brake pulsation employing a full vehicle dynamics CAE model. The full vehicle dynamic model was further studied to understand the impact of suspension tuning variation to brake pulsation performance. Brake torque variation (BTV) due to brake thickness variation from uneven rotor wear was represented mathematically in a sinusoidal form. The wheel assembly vibration from the brake torque variation is transmitted to driver interface points such as the seat track and the steering wheel. The steering wheel lateral acceleration at the 12 o’clock position, driver seat acceleration, and spindle fore-aft acceleration were reviewed to explore the physics of brake pulsation. It was found that the phase angle between the left and right brake torque generated a huge variation in brake pulsation performance. Multiple analyses have been run
Hong, Hyung-JooLee, ChangwookJun, HyochanZhu, Dongzhe
Driver’s license examinations require the driver to perform either a parallel parking or a similar maneuver as part of the on-road evaluation of the driver’s skills. Self-driving vehicles that are allowed to operate on public roads without a driver should also be able to perform such tasks successfully. With this motivation, the S-shaped maneuverability test of the Ohio driver’s license examination is chosen here for automatic execution by a self-driving vehicle with drive-by-wire capability and longitudinal and lateral controls. The Ohio maneuverability test requires the driver to start within an area enclosed by four pylons and the driver is asked to go to the left of the fifth pylon directly in front of the vehicle in a smooth and continuous manner while ending in a parallel direction to the initial one. The driver is then asked to go backwards to the starting location of the vehicle without stopping the vehicle or hitting the pylons. As a self-driving vehicle should do a much
Cao, XinchengGuvenc, Levent
Tire forces and moments play an important role in vehicle dynamics and safety. X-by-wire chassis components including active suspension, electronic powered steering, by-wire braking, etc can take the tire forces as inputs to improve vehicle’s dynamic performance. In order to measure the accurate dynamic wheel load, most of the researches focused on the kinematic parameters such as body longitudinal and lateral acceleration, load transfer and etc. In this paper, the authors focus on the suspension system, avoiding the dependence on accurate mass and aerodynamics model of the whole vehicle. The geometry of the suspension is equated by the spatial parallel mechanism model (RSSR model), which improves the calculation speed while ensuring the accuracy. A suspension force observer is created, which contains parameters including spring damper compression length, push rod force, knuckle accelerations, etc., combing the kinematic and dynamic characteristic of the vehicle. Subsequently, the
Zeng, TianyiLiu, ZeyuHe, ChenyuZeng, ZimoChen, HaotianZhang, FeiyangFu, KaiChen, Xinbo
ISO 26262-1:2018 defines the fault tolerant time interval (FTTI) as the minimum time span from the occurrence of a fault within an electrical / electronic system to a possible occurrence of a hazardous event. FTTI provides a time limit within which compliant vehicle safety mechanisms must detect and react to faults capable of posing risk of harm to persons. This makes FTTI a vital safety characteristic for system design. Common automotive industry practice accommodates recording fault times of occurrence definitively. However, current practice for defining the time of hazardous event onset relies upon subjective judgements. This paper presents a novel method to define hazardous event onset more objectively. The method introduces the Streetscope Collision Hazard Measure (SHMTM) and a refined approach to hazardous event classification. SHM inputs kinematic factors such as proximity, relative speed, and acceleration as well as environmental characteristics like traffic patterns
Jones, DarrenGangadhar, PavankumarMcGrail, RandallPati, SudiptaAntonsson, ErikPatel, Ravi
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