Browse Topic: Stability control

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Experimental Study on Quality Control and Variable Valve Timing Strategy of Hydrogen Engine for High Efficiency and Low Emission at Low Load2024-01-509510/15/2024
In order to reduce the pumping loss of low loads and maximize the lean combustion advantage of hydrogen, the paper proposes a load control strategy based on hydrogen mass, called quality control, for improving thermal efficiency and emissions at low loads. The advantages of quality control and the effect of VVT on the combustion performance of hydrogen internal combustion engines under low loads were discussed. The results show that when the relative air–fuel ratio (λ) increases to more than 2.5, the NOx emissions are reduced to less than 3.5 g/kW · h at the brake mean effective pressure (BMEP) below 8 bar, especially when the BMEP is less than 5 bar, the NOx is within 0.2 g/kW · h. Compared to quantity control based on air mass, the quality control strategy based on hydrogen mass achieves over a 2.0% reduction in pumping loss at BMEP levels lower than 4.4 bar. Furthermore, it enhances thermal efficiency by up to 5% at low loads, while maintaining NOx emissions within 0.2 g/kW · h at
Li, Yong, Chen, Hong, Fu, Zhen, Du, Jiakun, Wu, Weilong
Technical Paper
Recurrent Neural Network Model for On-Board Estimation of the Side-Slip Angle in a Four-Wheel Drive and Steering Vehicle15-17-01-000309/23/2023
Abstract A valuable quantity for analyzing the lateral dynamics of road vehicles is the side-slip angle, that is, the angle between the vehicle’s longitudinal axis and its speed direction. A reliable real-time side-slip angle value enables several features, such as stability controls, identification of understeer and oversteer conditions, estimation of lateral forces during cornering, or tire grip and wear estimation. Since the direct measurement of this variable can only be done with complex and expensive devices, it is worth trying to estimate it through virtual sensors based on mathematical models. This article illustrates a methodology for real-time on-board estimation of the side-slip angle through a machine learning model (SSE—side-slip estimator). It exploits a recurrent neural network trained and tested via on-road experimental data acquisition. In particular, the machine learning model only uses input signals from a standard road car sensor configuration. The model
Giuliacci, Tiziano Alberto, Ballesio, Stefano, Fainello, Marco, Mair, Ulrich, King, Julian
Journal Article
Recurrent Neural Network Model for On-Board Estimation of the Side-Slip Angle in a Four-Wheel Drive and Steering Vehicle15-17-01-0003-TEST-REC09/23/2023
Abstract A valuable quantity for analyzing the lateral dynamics of road vehicles is the side-slip angle, that is, the angle between the vehicle’s longitudinal axis and its speed direction. A reliable real-time side-slip angle value enables several features, such as stability controls, identification of understeer and oversteer conditions, estimation of lateral forces during cornering, or tire grip and wear estimation. Since the direct measurement of this variable can only be done with complex and expensive devices, it is worth trying to estimate it through virtual sensors based on mathematical models. This article illustrates a methodology for real-time on-board estimation of the side-slip angle through a machine learning model (SSE—side-slip estimator). It exploits a recurrent neural network trained and tested via on-road experimental data acquisition. In particular, the machine learning model only uses input signals from a standard road car sensor configuration. The model
Giuliacci, Tiziano Alberto, Ballesio, Stefano, Fainello, Marco, Mair, Ulrich, King, Julian
Journal Article
Improving Functionalities of Existing Electronic Stability Controller by adding Sensor Detection Based Algorithm for Collision Avoidance using CarSim.2022-01-116809/19/2022
With the advent of autonomous driving into mobility industry, passenger safety is of paramount importance. Electronic Stability Control (ESC) has been widely employed as an active safety feature in most of the modern cars, ESC is majorly based on differential braking, steer by wire or active torque distribution to prevent the vehicle from going off-course. However, ESC is limited to the discretion of the driver. Thus, the objective of this paper is to improve functionalities of existing electronic stability control by adding sensor detection-based algorithm for collision avoidance. The subject vehicle is installed with an existing default ESC & ABS system along with two range tracking sensors at front and rear and two blind spot detection sensors. The algorithm for collision avoidance has been tested in CarSim 2021.1. The procedure is tuned on different complex highway driving scenarios where a crate falls off from a traffic vehicle moving ahead of the subject vehicle along with
Shaikh, Parvez, Debnath, Sarnab, Kamble, Vijay, Mallikarjunaiah, Umesh
Technical Paper
Hierarchical Vehicle Stability Control Strategy Based on Unscented Kalman Filter Estimation2022-01-034303/29/2022
High-speed vehicle is prone to instability under bad road conditions, causing many safety accidents such as tail-flicking and overturning. Stability control could assist vehicle to drive safely and stably by adjusting the additional yaw moment. However, most of the existing stability control strategies directly invoke the information of the sideslip angle of the centroid that is difficult to obtain on the vehicle, and carry out complex controller design, which deviates from the actual application. In order to achieve a complete set of stability control architecture oriented to practical applications, this paper designs a hierarchical vehicle stability control strategy based on differential braking and state estimation technology. Firstly, a model oriented to state estimation and controller design is built according to the vehicle's motion state; Secondly, the sideslip angle of the centroid is accurately estimated through the unscented Kalman filter algorithm; Subsequently, the sliding
Zhang, Jian, Jiang, Hongwei, Li, Linrun, Liu, Qiuzheng, Wang, Yu, Liu, Jinbo, Gao, Yuan, Chen, Zhicheng
Technical Paper
On-board estimation of road adhesion coefficient based on ANFIS and UKF2022-01-034703/29/2022
The road adhesion coefficient has a great impact on the performance of vehicle tires, which in turn affects vehicle safety and stability. A low coefficient of adhesion can significantly reduce the tire's traction limit. Therefore, the measurement of the coefficient is much helpful for automated vehicle control and stability control. Considering that the road adhesion coefficient is an inherent parameter of the road and it cannot be known directly from the information of the on-vehicle sensors. The novelty of this paper is to construct a road adhesion coefficient observer which considers the noise of sensors and measures the unknown state variable by the trained neural network. A Butterworth filter and Adaptive Neural Fuzzy Interference System (ANFIS) are combined to provide the lateral and longitudinal velocity which cannot be measured by regular sensors. Unscented Kalman filter (UKF) considering vehicle model, wheel model, and tire model is proposed to estimate the road adhesion
Chen, Zixuan, Duan, Yupeng, Wu, Jinglai, Zhang, Yunqing
Technical Paper
Empowering the brake systems2021-01-126110/11/2021
Some researches show that the transport system is one of the main responsible for the emission of pollutants in the atmosphere. The growing demand for automobiles contrasts directly with the scarcity of inputs, planet temperature increasing and air quality degradation in large cities. This counterpoint is explored and discussed a lot, demanding that studies would be conducted to find out sustainable solutions in the production to end-customers. Instead of use fossil resources, one of the options to reduce gas emissions is the use of vehicles powered by electricity. When converting part of the vehicle's kinetic energy into electrical one its reduces emissions in the production electricity – power plants - as well burning gases in transport. Through technological innovations applied in brake systems with stability control embark safety and environment considering a single system.
Batagini, Emerson
Technical Paper
Monarch's automated, electric tractor ready for 2021 deliveries21TOFHP02_1002/01/2021
“If you want to fundamentally improve your economics,” said Monarch Tractor co-founder and CTO Zachary Omohundro to farmers and growers everywhere, “you go electric.” During a webcast with SAE International's Southern California Section featuring his startup company's battery-electric compact tractor, Omohundro offered markedly reduced operational costs as only one of many reasons for using the Monarch tractor, for which he said deliveries will start this fall for the “several hundred working farms” that have reserved the tractor that starts at $50,000.
Visnic, Bill
Magazine Article
Applying Automotive EDR Data to Traffic Crash Reconstruction Virtual Pre-Conference CertificationC201608/07/2020
EDR\'s were first installed in 1994 and are now installed in 99% of new light vehicles sold in the US. In the US EDR’s are not required, but vehicles with EDR’s made after 9/1/2012 must meet minimum standardized content requirements of 49 CFR, Part 563 including speed, throttle, brake on/off and Delta V. Data must be retrievable with a publicly available tool. Only a few manufacturers install EDR’s worldwide currently, but the EU and China are adopting regulations to require them in the next few years. Some manufacturers provide stability control system data far beyond the US regulation that aid in understanding vehicle movement in the 5 seconds prior to the crash. This course will provide the participant with the skills necessary to analyze EDR data that has already been imaged, apply it to crash reconstruction, and reconcile it with calculations using other data sources. The course will enable the participant to analyze current and potential future EDR data set without regard to
Instructor Led
Articulated Vehicle Lateral Stability Management via Active Rear-Wheel Steering of Tractor Using Fuzzy Logic and Model Predictive Control02-13-02-000807/01/2020
In-phase rear-wheel steering, where rear wheels are steered in the same direction of front wheels, has been widely investigated in the literature for vehicle stability improvements along with stability control systems. Much faster response can be achieved by steering the rear wheels automatically during an obstacle avoidance maneuver without applying the brakes where safe stopping distance is not available. Sudden lane change movements still remain challenging for heavy articulated vehicles, such as tractor and semitrailer combinations, particularly on roads with low coefficient of adhesion. Different lateral accelerations acting on tractor and semi-trailer may cause loss of stability resulting in jackknifing, trailer-swing, rollover, or slip-off. Several attempts have been made in the literature to use active steering of semi-trailer’s rear wheels to prevent jackknifing and rollover. However, loss of stability in an articulated vehicle is usually caused by an oversteered tractor, and
Sahin, Hasan, Akalin, Ozgen
Journal Article
A Novel Kalman Filter Based Road Grade Estimation Method2020-01-056304/14/2020
Accurate, robust and real-time estimation of road grade is extremely important in vehicle control (battery management, transmission shift scheduling, distance-to-empty prediction, anti-lock braking system, collision avoidance, stability control, etc.) to improve safety, stability, efficiency and performance. This paper presents a novel Kalman filter based road grade estimation method using measurements from an accelerometer, gyroscope and tachometer. The accelerometer measures the components of the vehicle acceleration (including the components of the acceleration due to gravity), and the measurements provided by the accelerometer are almost drift free but heavily corrupted by measurement noises. The gyroscope measures the components of the angular velocity of the vehicle, and the measurements provided by the gyroscope are quite clean but disturbed by gyroscope biases. The tachometer measures the longitudinal vehicle velocity, and the measurement provided by the tachometer is also
Gokcek, Cevat
Technical Paper
Effect of Stator Surface Area on Braking Torque and Wall Heat Dissipation of Magnetorheological Fluid Retarder2020-01-093704/14/2020
Magnetorheological fluid (MRF) is used as the transmission medium of the hydraulic retarder. The rheological properties are regulated by changing the magnetic field to achieve accurate control of the retarder's braking torque. Under the action of the external magnetic field, the flow structure and performance of the MRF retarder will be changed in a short time. The apparent viscosity coefficient increases by several orders of magnitude, the fluidity deteriorates and the heat generated by the brake cannot be transferred through the liquid circulation, which will affect the braking torque of the retarder. Changing the surface area of the stator also has an influence on the braking torque of the retarder and the wall heat dissipation. In this study, the relationship between the braking torque of the MRF retarder and the stator surface area of the retarder was analyzed. In addition, phase change materials were used to directly dissipate heat on the retarder surface to improve the heat
Liu, ZhiQiang, Tan, Gangfeng, Tian, Zhongpeng, Zhou, Mi, Agyeman, Philip, Frimpong, Justice
Technical Paper
A Pre-Warning Method for Cornering Speed of Concrete Mixer Truck2020-01-100304/14/2020
The high gravity center of the concrete mixer truck reduces the truck’s stability while steering. The rolling stirring tank makes the stability even worse than the regular engineering vehicle due to the dynamic variation of the centroid position. Most of the researches on the rollover stability of concrete mixer trucks focus on the rollover model establishment and dynamic simulation module. The change of concrete centroid is ignored when the safety cornering speed is calculated. This paper proposes a pre-warning method for the cornering speed of concrete mixer trucks based on centroid dynamic simulation. In the method, the mixing tank stirring model and the vehicle driving dynamic model are established on the Fluent and TruckSim simulation platforms, respectively. The theoretical speed threshold obtained by simulation is used as the evaluation index of the warning speed in the curve. Firstly, the dynamic simulation of the stirring tank model is carried out by Fluent. According to
Jiang, Yifeng, Tan, Gangfeng, Wang, Haoyu, Wang, Zelong, Wang, Zhenyu, Li, Ming
Technical Paper
An Efficient, High-Precision Vehicle Testing Procedure to Evaluate the Efficacy of Fuel-Borne Friction Modifier Additives2019-01-235312/19/2019
Improved fuel economy is increasingly a key measure of performance in the automotive industry driven by market demands and tighter emissions regulations. Within this environment, one way to improve fuel economy is via fuel additives that deliver friction- reducing components to the piston-cylinder wall interface. Whilst the use of friction modifiers (FMs) in fuel or lubricant additives to achieve fuel economy improvements is not new, demonstrating the efficacy of these FMs in vehicles is challenging and requires statistical design together with carefully controlled test conditions. This paper describes a bespoke, efficient, high-precision vehicle testing procedure designed to evaluate the fuel economy credentials of fuel-borne FMs. By their nature, FMs persist on engine surfaces and so their effects are not immediately reversible upon changing to a non FM-containing fuel (“carryover” effect), therefore requiring careful design of the test programme. The solution presented here
Yow, Shuhui, Ziman, Pauline, Smith, Sue J., Walter, Dr. Marc, Bacchi, Robert J.
Technical Paper
Analysis of Active Collision Avoidance Performance Based on Cooperative Regenerative Auxiliary Braking System2019-01-502711/04/2019
Active collision avoidance can assist drivers to avoid longitudinal collision through active brake. Regenerative braking can improve the driving range and braking response speed. At this stage, conventional hydraulic braking system limits the implements of above technologies because of its poor performance of response speed and coordinated control. While the brake-by-wire system is a better actuator that can fulfill requirements of automotive electric and intelligent development due to its rapid response and flexible adjustment. However, the system control algorithm becomes more complicated with introduction of regenerative braking and active collision avoidance function, which is also the main problem solved in this paper. First, a new type of cooperative regenerative auxiliary braking system (CRABS) of intelligent electric vehicles, which integrates the functions of brake-by-wire, regenerative braking and active collision avoidance, is proposed, for purpose of analyzing the
Hou, Xiaohui, Zhang, Junzhi, Zhang, Zhongshi, He, Chengkun
Technical Paper
Comparative Analysis between American and European Requirements for Electronic Stability Control (ESC) Focusing on Commercial Vehicles2019-01-214109/15/2019
Analysis of road accidents has shown that an important portion of fatal crashes involving Commercial Vehicles are caused by rollovers. ESC systems in Commercial Vehicles can reduce rollovers, severe understeer or oversteer conditions and minimize occurrences of jackknifing events. Several studies have estimated that this positive effect of ESC on road safety is substantial. In Europe, Electronic Stability Control (ESC) is expected to prevent by far the most fatalities and injuries: about 3,000 fatalities (-14%), and about 50,000 injuries (-6%) per year. In Europe, Electronic Stability Control Systems is mandatory for all vehicles (since Nov. 1st, 2011 for new types of vehicle and Nov. 1st, 2014 for all new vehicles), including Commercial Vehicles, Buses, Trucks and Trailers. On 2015, NHTSA published Federal Motor Vehicle Safety Standard (FMVSS) No. 136, Electronic Stability Control systems for heavy vehicles, requiring Electronic Stability Control (ESC) systems on truck tractors and
Iombriller, Silvia Faria, Bolognesi Prado, Wesley, Silva, Marco Andre
Technical Paper
The Rodney Dangerfield of Automated-Driving Sensors19AVEP07_0607/01/2019
Radar and lidar get all the attention, but Inertial Measurement Units are the backbone of sensor fusion. Suppliers are scrambling to make IMUs more accurate-and much less expensive. The emerging era of highly-automated driving comes courtesy of much-vaunted sensor technology-spinning lasers, penetrating radar, sonar blips. But the sensor that gets the least respect in the technology stack could be the lynchpin for the mass roll-out of self-driving vehicles: the inertial measurement unit (IMU). “IMUs are the glue that binds everything together,” said Mike Horton, chief technology officer at Aceinna, a Boston-based company that develops sensing solutions for automotive applications. “An IMU can help bring different types of data together from GNSS (Global Navigation Satellite System), lidar and cameras to make everything consistent and smooth.”
Berman, Bradley
Magazine Article
Jeep revives its pickup mojo with 2020 Gladiator19AUTP05_1505/01/2019
Get ready for the fractionalization of the U.S.'s raucous pickup-truck market. Launching what's surely one of the year's most-anticipated and potentially significant new models, Jeep engineers and planners insist they went out of their way to ensure the 2020 Gladiator was developed as a genuine pickup and not “a Wrangler with a bed.” But everyone knows Jeep would've been crazy to stray too far from the radiant demand for the new JL-generation Wrangler, so excuse us if the Gladiator does, well, at least look like just that: a 4-door Wrangler Unlimited-with a bed.
Visnic, Bill
Magazine Article
Pressure Estimation Algorithms in Decoupled Electro-Hydraulic Brake System Considering the Friction and Pressure-Position Relationship2019-01-043804/02/2019
This paper presents several pressure estimation algorithms (PEAs) for a decoupled electro-hydraulic brake system (EHB), which is driven by an electric motor + reduction gear. Most of the pressure control solutions are based on standard pressure-based feedback control, requiring a pressure signal. Although the pressure sensor can produce the pressure feedback signal, it will increase cost and enlarge installation space. The rotation angle of electric motor is available by the built-in sensor, so the pressure can be estimated by using the rotation angle. Considering the typical nonlinearities (i.e. friction, pressure-position relationship) and uncertainties (i.e. disturbance caused by friction model), the estimation-oriented model is established. The LuGre model is selected to describe the friction, and the pressure-position relationship is fitted by a quadratic polynomial. Based on the estimation-oriented model, the force-based PEA (FPEA) and the interconnected PEA (IPEA) are designed
Han, Wei, Xiong, Lu, Yu, Zhuoping
Technical Paper
Safety and Lateral Dynamics Improvement of a Race Car Using Active Rear Wing Control2019-01-064304/02/2019
As the forward speed of a car increases, the safety of the vehicle and the driver becomes a more significant concern. Active aerodynamic control can effectively enhance the lateral stability of high speed vehicles over tight cornering maneuvers. A split rear wing has been proposed. By means of manipulating the attack angles for the right and/or left parts of the split rear wing, a favorable yaw moment may be achieved to ensure the lateral stability of the vehicle. However, active control of the split rear wing has not been adequately explored. This paper proposes a novel active split rear wing, which can improve the lateral stability over tight cornering maneuvers, and will not degrade the longitudinal dynamics of the vehicle. A Linear Quadratic Regulator (LQR) based controller for the active split rear wing is designed using a linear vehicle model. In order to examine the performance of the active split rear wing, Numerical simulation is carried out using the LQR based controller and
Hammad, Mohammed, Qureshi, Khizar, He, Yuping
Technical Paper
Road Tested19AVEP03_1103/01/2019
Transportation-infrastructure expert Kirk Steudle reflects on the rapid progress toward the connected-AV future and the challenges ahead. In the auto industry, mechanical and electrical engineers work from the tire up. Civil engineers work from the tire down,” quips Kirk Steudle. “And although it's taken a while for both to understand each other's jargon, the connected-and-autonomous vehicle is forcing them all together-to solve problems for society's mobility.” Steudle, a registered professional engineer, has been at the vehicle-to-road nexus his entire career. Last October he retired as director of the Michigan Dept. of Transportation where, among many achievements, his leadership helped put the state and its core industry in the vanguard of connected-car and AV-related developments, testing, and infrastructure standards. During his final year at MDoT, he also served as interim CEO of the American Center for Mobility, the new 500-acre AV proving ground and test center near Ann Arbor.
Brooke, Lindsay
Magazine Article
WHAT WE'RE DRIVING19AUTP03_0903/01/2019
When the Tribeca, Subaru's first shot (2009) at a three-row SUV, didn't quite deliver the goods in this brutally competitive segment and went away in 2014, Fuji Heavy planners went right to work on the replacement-the all-new Ascent. It's more aesthetically pleasing, boasts a lighter and stiffer global architecture (long-wheelbase version of the latest Impreza sedan) and is better-designed and -equipped inside. The Ascent Premium is the first price-walk up from the base car. The one I tested stickered at $39,430, outfitted with a moonroof and comprehensive ‘Starlink’ navi-tainment suite worth $4,200. Standard Ascent propulsion comes from Subaru's 2.4-L flat-four gasoline engine, turbocharged to deliver 260 hp (194 kW). It's coupled with Fuji's own TR690 CVT and torque-vectoring AWD, all capable of pulling a 5,000-lb (2268-kg) trailer. While I did not tow during my time with the Ascent, under normal loads and hard acceleration the ‘boxer’ engine and CVT can be comparatively noisy and
Magazine Article
Movement Prediction Hypotheses for Pedestrians and Trajectory Planning for Cooperative Driving Systems12-02-01-000212/19/2018
It is a challenge to find a safe trajectory for automated vehicles in urban environments with pedestrians. The prediction of future movements with 100% certainty is impossible, if the intention is unknown. A Gaussian process approach is used to formulate future movement hypotheses of the pedestrian based on historical movements. A mixed integer linear programming (MILP) optimization approach is used for the trajectory planning of the vehicle. The collision probability between the ego-vehicle and pedestrian is used as constraints in the optimization. This approach is useful for cooperative vehicle systems, with historical movement data in a fixed urban environment (e.g., intersection) and the premise that pedestrians follow typical movement data.
Hartmann, Michael, Stolz, Michael, Watzenig, Daniel
Journal Article
Trajectory-Tracking Control for Autonomous Driving Considering Its Stability with ESP2018-01-163908/07/2018
With rapid increase of vehicles on the road, safety concerns have become increasingly prominent. Since the leading cause of many traffic accidents is known to be by human drivers, developing autonomous vehicles is considered to be an effective approach to solve the problems above. Although trajectory tracking plays one of the most important roles on autonomous driving, handling the coupling between trajectory-tracking control and ESP under certain driving scenarios remains to be challenging. This paper focuses on trajectory-tracking control considering the role of ESP. A vehicle model is developed with two degrees of freedom, including vehicle lateral, and yaw motions. Based on the proposed model, the vehicle trajectory is separated into both longitudinal and lateral motion. The coupling effect of the vehicle and ESP is analyzed in the paper. The lateral trajectory-tracking algorithm is developed based on the preview follower theory. Spacing control strategy is used in longitudinal
Pan, Fei, Deng, Weiwen, Zhang, Sumin, Wang, Jinsong, Wang, Shanshan
Technical Paper
Consideration of Effective Chassis Control in Electric Vehicle2018-01-503508/06/2018
In this study, we focus on “camber angle control” and “derivative steering assistance” using “steer-by-wire” as maneuverability and stability improvement techniques that are appropriate for the electric vehicle (EV) era. Movements that produce a negative camber angle generate camber thrust, and vehicle motion performance improvements extend from the fact that the tire side force is increased by the camber thrust effect. In our experimental vehicle, a proportional steering angle system was used to create negative camber angle control via an electromagnetic actuator that allowed us to confirm improvements to both the effectiveness and stability of steering control in restricted cornering areas. More specifically, we determined that it is possible to improve critical cornering performance by executing ground negative camber angle control in proportion to the steering angle. Steer-by-wire refers to an electrical steering technique that allows the steering angle of the entire vehicle to be
Yamaguchi, Ryo, Nozaki, Hiromichi
Technical Paper
Research on Regenerative Braking Control Strategy of Distributed EV based on Braking Intention2018-01-134204/03/2018
Focusing on distributed electric vehicles with in-wheel motors, a novel regenerative braking control strategy based on braking intention is proposed. Firstly, a design scheme for the regenerative braking system is described. Four in-wheel motors and an Electro-Hydraulic Braking (EHB) system are respectively designed for regenerative braking and hydraulic braking. Then, Braking intention recognition self-learning libraries are trained based on Hidden Markov Model method, which is validated by driver-in-loop tests. According to three speed states and four braking intentions, the regenerative braking control strategy for multiple brake modes is developed. The coefficient of regenerative braking is defined to describe the intervening time and proportion of motor maximum regenerative braking. Eventually, the co-simulation results show that the proposed strategy can not only significantly improve the energy recovery capability, but also provide the coordinated control of regenerative braking
Pan, Hao, Guo, Xuexun, Pei, Xiaofei, Pan, Jin, Zhang, Jie
Technical Paper
A Braking Force Distribution Strategy in Integrated Braking System Based on Wear Control and Hitch Force Control2018-01-082704/03/2018
A braking force distribution strategy in integrated braking system composed of the main braking system and the auxiliary braking system based on braking pad wear control and hitch force control under non-emergency braking condition is proposed based on the Electronically Controlled Braking System (EBS) to reduce the difference in braking pad wear between different axles and to decrease hitch force between tractors and trailers. The proposed strategy distributes the braking force based on the desired braking intensity, the degree of the braking pad wear and the limits of certain braking regulations to solve the coupling problems between braking safety, economical efficiency of braking and the comfort of drivers. Computer co-simulations of the proposed strategy are performed. The braking force distribution strategy is verified under condition of equal wear of braking pad, condition of greater wear on the front axle of tractor and condition of greater wear on the rear axle of the tractor
Zheng, Hongyu, Liu, Chen, Wang, Linlin
Technical Paper
Integrated Chassis Control for Vehicle Stability under Various Road Friction Conditions2018-01-055204/03/2018
This paper presents an integrated chassis control method for vehicle stability under various road friction conditions without information on tire-road friction. For vehicle stability, vehicle with an integrated chassis control needs to cope with the various road friction conditions. One of the chassis control method under various road conditions is to determine and/or limit control inputs based on tire-road friction coefficient. The tire-road friction coefficient, however, is difficult to estimate and still a challenging task. The key idea for the proposed method without the estimation of the tire-road friction coefficient is to analyze and control vehicle states based on a tire slip angle - tire force phase plane, i.e. based on these vehicle responses: tire forces and tire slip angles of front/rear wheels. Based on the phase plane, vehicle instability is detected and the vehicle is controlled to regain the vehicle stability and maneuverability under various road conditions without
Joa, Eunhyek, Yi, Kyongsu, Bae, Hyungjune, Sohn, Kimo
Technical Paper
Autonomous Robotic Self-RightingTBMG-2869904/01/2018
Robots are increasingly being used for various applications including search and rescue operations and combat situations. Unfortunately, during the performance of maneuvers, a robot may fall or tip over, preventing it from moving normally. Controlling the robot to successfully right itself can be a difficult and time-consuming task for operators — a major problem in situations that may be both time-sensitive and dangerous; for example, those controlling the robot must determine how to re-orient the robot to a desired position, if it is possible.
Magazine Article
Automotive Stability Enhancement SystemsJ2564_201711 (Current)11/14/2017
The purpose of this SAE Information Report is to describe currently known automotive active stability enhancement systems, as well as identify common names which can be used to refer to the various systems and common features and functions of the various systems. The primary systems discussed are: a ABS - Antilock Brake Systems b TCS - Traction Control Systems c ESC - Electronic Stability Control The document is technical in nature and attempts to remain neutral regarding unique features that individual system or vehicle manufacturers may provide.
Vehicle Dynamics Standards Committee
Information Report
M xDrive: BMW's power + grip solution17AUTP11_1311/01/2017
Channeling 591 hp (441 kW) and 553 lb·ft (750 N·m) through a pair of hand-sized contact patches was always going to be a challenge, even for the engineers at BMW's M division. “Four years ago we knew we had to find the right solution for the sixth-generation M5 since it was going to have a considerable power hike,” Dirk Hacker, Vice President Engineering for the M division told Automotive Engineering at the 2017 Frankfurt Motor Show.
Adcock, Ian
Magazine Article
Local Path Planning for Intelligent Vehicle Obstacle Avoidance Based on Dubins Curve and Tentacle Algorithm2017-01-195109/23/2017
Local path planning for obstacle avoidance is one of the core topics of intelligent vehicle. A novel method based on dubins curve and tentacle algorithm is proposed in this article, with the consideration of obstacle avoidance and vehicle motion constraints. First, the preview distance of the vehicle is given according to the current speed, so that the preview point can be found with the information of global path. Then dubins curve is adopted to find a path with appropriate turning radius, between the current position and preview point, satisfying the constraints of current direction and target direction, considering handling and ride comfort of the vehicle. In order to avoid obstacle, tentacle algorithm is adopted. 20 tentacle points are given by moving the original preview point, and then 21 local paths can be given by using dubins curve. Cost function is used to find out the best option of the 21 paths. The distance to obstacle, the final distance to original preview point and the
Wu, Lingfei, Zha, Hongshan, Xiu, Caijing, He, Qiaojun
Technical Paper
Brake System Regulations and Standards Review and Comparison Focused on Europe, NA and SA Markets2017-01-253409/17/2017
Considering that the most part of commercial vehicles are equipped with air brakes it is very important assure specific technical requirements for air brake system and its components. In addition, the effects of brake system failure are more critical for commercial vehicles which require more attention on their requirements details. Historically, the development of air brakes technology started on North America and Europe and consequently two strong and distinct resolutions were structured: FMVSS 121 and ECE R.13, respectively. For passenger cars were developed the ECER.13H to harmonize North American and European resolutions. However, for commercial vehicles regional applications, culture and implementation time must be considered. These commercial vehicles peculiarities must be understood and their specific requirements harmonized to attend the global marketing growth. This article shows a review of the North American and European air brake requirements and also discusses their
Iombriller, Silvia Faria, Bolognesi Prado, Wesley
Technical Paper
The Design and Evaluation of EMB Actuator Scheme2017-01-250909/17/2017
Electromechanical Braking System (EMB) stops the wheel by motor and related enforce mechanism to drive braking pads to clamp the friction plate. It is compact in sized as well as faster in response, which solves the issue of potential leakage and slows response of traditional hydraulic brake system. The institutions at home and abroad have put forward all kinds of new structural schemes of EMB. At present, there are various EMB structural schemes, but the analysis and evaluation of these schemes are relatively few. In this paper, on the basis of a large number of research, the EMB actuator is modular decomposed according to function ,then the parametric 3D model library of each function module is established. According to brake requirements of the target vehicle, a development platform is set up to match EMB actuator structure scheme quickly. Moreover, the analysis and evaluation of several typical schemes are accomplished by analytic hierarchy process, providing reference for
Zhuo, Guirong, Xue, Ruonan, Zhang, Subin, Wu, Cheng, Xiong, Kun
Technical Paper
Road-efficient mud machine17AUTP04_0504/01/2017
Jeep's all-new 2017 Compass gets its go-anywhere guts from GKN's AWD system. Replacing the decade-old Jeep Compass is the new-for-2017 Compass, FCA's (and Jeep's) first truly global vehicle program. Styled to resemble a slightly scaled-down Grand Cherokee, the new C-segment SUV is being produced in four plants (Mexico, China, India and Brazil) and offered in 17 powertrain combinations that include diesels and 6-speed manual gearboxes. The U.S. gets the manual ‘box but not the diesel. The new Compass is based on a stretched version of FCA's so-called “small-wide 4×4” vehicle architecture that also underpins the smaller Jeep Renegade. That platform is designed primarily as front-wheel-drive and accommodates nicely the axle-disconnect all-wheel-drive system supplied by GKN (see sidebar). As a “4.4-meter” car designed to fit European and other global parking spaces, the Jeep's overall length is 173 in (4394 mm), riding on a 103.8 in (2636 mm) wheelbase.
Brooke, Lindsay
Magazine Article
Yaw Rate Based Trailer Hitch Angle Estimation for Trailer Backup Assist2017-01-002703/28/2017
In the current Ford Pro-Trailer Backup Assist (TBA) system, trailer hitch angle is determined utilizing the reverse camera of the vehicle. In addition to being sensitive to environmental factors such as lighting conditions and occlusion, the vision-based approach is difficult to be applied to gooseneck or fifth wheel trailers. In this paper, a yaw rate based hitch angle observer is proposed as an alternative sensing solution for TBA. Based on the kinematic model of the vehicle-trailer, an instantaneous hitch angle is first derived by utilizing vehicle yaw rate, trailer yaw rate, vehicle velocity and vehicle/trailer parameters provided by the TBA system. Due to signal errors and parameter uncertainties, this instantaneous hitch angle may be noisy, especially at lower vehicle speed. To improve the estimation accuracy, a Kalman filter (or an extended Kalman filter) which is based on the vehicle-trailer kinematic model is then formulated to obtain the optimal estimate, with the
Xu, Li, Tseng, Eric, Pilutti, Thomas, Schondorf, Steven
Technical Paper
Research on Vehicle Stability Control Strategy Based on Integrated-Electro-Hydraulic Brake System2017-01-156503/28/2017
A vehicle dynamics stability control system based on integrated-electro-hydraulic brake (I-EHB) system with hierarchical control architecture and nonlinear control method is designed to improve the vehicle dynamics stability under extreme conditions in this paper. The I-EHB system is a novel brake-by-wire system, and is suitable to the development demands of intelligent vehicle technology and new energy vehicle technology. Four inlet valves and four outlet valves are added to the layout of a conventional four-channel hydraulic control unit. A permanent-magnet synchronous motor (PMSM) provides a stabilized high-pressure source in the master cylinder, and the four-channel hydraulic control unit ensures that the pressures in each wheel cylinder can be modulated separately at a high precision. Besides, the functions of Anti-lock Braking System, Traction Control System and Regenerative Braking System, Autonomous Emergency Braking can be integrated in this brake-by-wire system. A sliding
He, Xiangkun, Yang, Kaiming, Ji, Xuewu, Liu, Yahui, Deng, Weiwen
Technical Paper
Yaw Stability Enhancement of Articulated Commercial Vehicles via Gain-Scheduling Optimal Control Approach2017-01-043703/28/2017
In this paper, a gain-scheduling optimal control approach is proposed to enhance yaw stability of articulated commercial vehicles through active braking of the proper wheel(s). For this purpose, an optimal feedback control is used to design a family of yaw moment controllers considering a broad range of vehicle velocities. The yaw moment controller is designed such that the instantaneous tractor yaw rate and articulation angle responses are forced to track the target values at each specific vehicle velocity. A gain scheduling mechanism is subsequently constructed via interpolations among the controllers. Furthermore, yaw moments derived from the proposed controller are realized by braking torque distribution among the appropriate wheels. The effectiveness of the proposed yaw stability control scheme is evaluated through software-in-the-loop (SIL) co-simulations involving Matlab/Simulink and TruckSim under lane change maneuvers. Simulation results demonstrate that the proposed gain
Li, Bin, Rakheja, Subhash
Journal Article
Vehicle Lane Change Automation with Active Steering - Theoretical Studies and Numerical Investigations2017-01-155503/28/2017
Lane change automation appears to be a fundamental problem of vehicle automated control, especially when the vehicle is driven at high speed. Selected relevant parts of the recent research project are reported in this paper, including literature review, the developed models and control systems, as well as crucial simulation results. In the project, two original models describing the dynamics of the controlled motion of the vehicle were used, verified during the road tests and in the laboratory environment. The first model - fully developed (multi-body, 3D, nonlinear) - was used in simulations as a virtual plant to be controlled. The second model - a simplified reference model of the lateral dynamics of the vehicle (single-body, 2D, linearized) - formed the basis for theoretical analysis, including the synthesis of the algorithm for automatic control. That algorithm was based on the optimal control theory. The algorithm includes the determination of time optimal reference profiles
Gidlewski, Mirosław Jan, JANKOWSKI, Krystof, MUSZYŃSKI, Andrzej, ŻARDECKI, Dariusz
Technical Paper
Optimal Tire Force Control & Allocation for Longitudinal and Yaw Moment Control of HEV with eAWD Capabilities2017-01-155803/28/2017
Hybrid Electric Vehicles (HEV) offer improved fuel efficiency compared to their conventional counterparts at the expense of adding complexity and at times, reduced total power. As a result, HEV generally lack the dynamic performance that customers enjoy. To address this issue, the paper presents a HEV with eAWD capabilities via the use of a torque vectoring electric rear axle drive (TVeRAD) unit to power the rear axle. The addition of TVeRAD to a front wheel drive HEV improves the total power output. To further improve the handling characteristics of the vehicle, the TVeRAD unit allows for wheel torque vectoring at the rear axle. A bond graph model of the proposed drivetrain model is developed and used in co-simulation with CarSim. The paper proposes a control system which utilizes tire force optimization to allocate control to each tire. The optimization algorithm is used to obtain optimal tire force targets to at each tire such that the targets avoid tire saturation. The Youla
Kuang, Ming, Velazquez Alcantar, Jose, Assadian, Francis
Journal Article
Development of Decentralized Integrated Chassis Control for Vehicle Stability in Limit Handling2016-01-810609/27/2016
As we move towards the world of autonomous vehicles it becomes increasingly important to integrate several chassis control systems to provide the desired vehicle stability without mutual interference. The principles for integration proposed in existing technical literature are majorly centralized which are not only computationally expensive but does not fit the current supplier based OEM business model. An Automotive OEM brings multiple suppliers on-board for developing the Active Safety systems considering several factors such as cost, quality, time, ease of business etc. When these systems are put together in the vehicle they may interfere with each other’s function. Decoupling their function results in a need of heavy calibration causing performance trade-offs and loss in development time. This puts forward a need for an algorithm which integrates individual control systems supplied by different vendors and enable them to function simultaneously to meet the vehicle dynamics
Kolte, Sameer, Srinivasan, Ananth Kumar, Srikrishna, Akilla
Journal Article
GEMINI Stability Control for Reducing Pointing Jitter in CubeSats and SmallsatsTBMG-2495607/01/2016
Because of the cost-effectiveness of flying smallsats compared to large flagship spacecraft, there is increasing interest in boosting their capabilities for supporting precision science payloads and sophisticated instrumentation. Unfortunately, a major current drawback with using smallsats is their inability to hold the pointing line-of-sight steady without jittering. Line-of-sight jitter degrades observations made by cameras and other imaging-type instruments, and fundamentally limits the quality of science that can be obtained.
Magazine Article
The e-LSD alternative to AWD16AUTP05_0505/01/2016
Eaton's new-for-2018 electronic limited-slip differential offers mass, fuel-consumption, and packaging benefits over typical AWD while enhancing vehicle dynamic control. Is engineering a new vehicle for all-wheel drive worth the cost, weight, and fuel consumption penalties for perhaps 10% of volume on some platforms? For mass-market C- and D-segment sedans, forcing the packaging penalty of a propshaft tunnel on 100% of production in order to accommodate a small portion of AWD models may not be a worthwhile tradeoff given the pressures of meeting 2025 CAFE and European CO2 laws. Some vehicle planners and chief engineers who have weighed these options say a high-performing electronic limited-slip differential (e-LSD) coupled with either front- or rear-wheel drive can satisfy most of the AWD performance expectation.
Brooke, Lindsay
Magazine Article
A Robust Stability Control System for a Hybrid Electric Vehicle Equipped with Electric Rear Axle Drive2016-01-164904/05/2016
Optimizing/maximizing regen braking in a hybrid electric vehicle (HEV) is one of the key features for increasing fuel economy. However, it is known [1] that maximizing regen braking by braking the rear axle on a low friction surface results in compromising vehicle stability even in a vehicle which is equipped with an ESP (Enhanced Stability Program). In this paper, we develop a strategy to maximize regen braking without compromising vehicle stability. A yaw rate stability control system is designed for a hybrid electric vehicle with electric rear axle drive (ERAD) and a “hang on” center coupling device which can couple the front and rear axles for AWD capabilities. Nonlinear models of the ERAD drivetrain and vehicle are presented using bond graphs while a high fidelity model of the center coupling device is used for simulation. A robust yaw rate stability controller, utilizing Youla parameterization, is proposed which uses the center coupling device to distribute regen braking torque
Velazquez Alcantar, Jose, Assadian, Farhad
Journal Article
A Fuzzy Inference System for Understeer/Oversteer Detection Towards Model-Free Stability Control2016-01-163004/05/2016
In this paper, a soft computing approach to a model-free vehicle stability control (VSC) algorithm is presented. The objective is to create a fuzzy inference system (FIS) that is robust enough to operate in a multitude of vehicle conditions (load, tire wear, alignment), and road conditions while at the same time providing optimal vehicle stability by detecting and minimizing loss of traction. In this approach, an adaptive neuro-fuzzy inference system (ANFIS) is generated using previously collected data to train and optimize the performance of the fuzzy logic VSC algorithm. This paper outlines the FIS detection algorithm and its benefits over a model-based approach. The performance of the FIS-based VSC is evaluated via a co-simulation of MATLAB/Simulink and CarSim model of the vehicle under various road and load conditions. The results showed that the proposed algorithm is capable of accurately indicating unstable vehicle behavior for two different types of vehicles (SUV and Sedan). The
Hirche, Benjamin, Ayalew, Beshah
Journal Article
A Model-Free Stability Control Design Scheme with Active Steering Actuator Sets2016-01-165504/05/2016
This paper presents the application of a proposed fuzzy inference system as part of a stability control design scheme implemented with active steering actuator sets. The fuzzy inference system is used to detect the level of overseer/understeer at the high level and a speed-adaptive activation module determines whether an active front steering, active rear steering, or active 4 wheel steering is suited to improve vehicle handling stability. The resulting model-free system is capable of minimizing the amount of model calibration during the vehicle stability control development process as well as improving vehicle performance and stability over a wide range of vehicle and road conditions. A simulation study will be presented that evaluates the proposed scheme and compares the effectiveness of active front steer (AFS) and active rear steer (ARS) in enhancing the vehicle performance. Both time and frequency domain results are presented.
Hirche, Benjamin, Ayalew, Beshah
Journal Article
Passengers First Light Truck - A Modern Take on a Narrow Wake2016-01-133304/05/2016
Individuals in the United States consume twice as much energy as those in any other region. Solitary workday commutes in light vehicles are the leading reason for this difference. An electric vehicle design is proposed to help catalyze more social, higher occupancy, commuting habits - through application of existing technology. Performance criteria are: 1) attract passengers to the suburban front yard at 6:30 AM, 2) match market leading crash test performance, cargo capability, and sense of freedom, and 3) deliver easier parking, better acoustics and better passenger mile efficiency. A vehicle as a rolling event venue determines a large windscreen, side-by-side upright seating arrangements, and acoustic excellence -an experience where there are only good seats. These requirements force a decision to close the wake along a vertical line to form a narrow wake. The chassis is platform batteries with dual motor electric rear drive and undetermined front drive. Findings: 1 Narrow wake
Fontana, Edward C.
Technical Paper
Determination of Critical Speed, Slip Angle and Longitudinal Wheel Slip based on Yaw Marks Left by a Wheel with Zero Tire Pressure2016-01-148004/05/2016
This article presents the results of an analysis of the yaw marks left by a car with normal pressure in all tires and then normal pressure in three tires and zero in one rear tire. The analysis is a continuation of research on influence of reduced tire pressure on car lateral dynamics in a passing maneuver, discussed in the SAE paper No. 2014-01-0466. Preliminary analysis of yaw marks has shown, that a wheel with zero pressure deposits a yaw mark whose geometry differs from the yaw mark made by a wheel with normal pressure based on which we could calculate: critical speed, slip angle and longitudinal wheel slip. The aim of the presented research was to analyze the yaw marks left by car with zero pressure in one rear wheel in order to check the possibility of determining the vehicle critical speed, slip angle and longitudinal wheel slip. It was reached by performing bench and road tests during which the vehicle motion parameters were recorded using GPS Data Logging System. The results
Zebala, Jakub, Wach, Wojciech, Ciępka, Piotr, Janczur, Robert
Technical Paper
Vehicle Side Slip and Roll Angle Estimation2016-01-165404/05/2016
Vehicle dynamics estimation has been the subject of study for some years now. If on-board vehicle control systems can be provided with information such as side slip angle, lateral force etc. then stability of the vehicle can be improved. To estimate these dynamic variables different observers have been used e.g., sliding mode, fuzzy logic, neural networks etc. In this article the authors propose an extended Kalman filter to estimate vehicle side slip angle. Roll angle is estimated using vertical loads as input. First, a linear Kalman filter is used to filter out the vertical forces and estimate roll angle. This information is then used to estimate the vehicle side slip angle. To take into account the nonlinearities concerning lateral vehicle dynamics, Pacejka magic formula is used to model lateral forces. Estimated results are then compared with simulations, showing good accuracy.
Syed, Umair Hussain, Vigliani, Alessandro
Technical Paper
Automatic braking pact for 2022 will alter systems development16AUTP04_0404/01/2016
Vehicle OEMs have pledged to make automatic emergency braking (AEB) a standard feature by 2022, a move that is likely to alter electronic architectures and increase collaboration between module suppliers. Twenty automakers recently teamed up with the U.S. National Highway Traffic Safety Admin. and the Insurance Institute for Highway Safety to set voluntary programs to move emergency braking from a luxury option to mainstream vehicles over the next few years.
Costlow, Terry
Magazine Article
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