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Technical Paper
2014-09-28
Dongmei wu
With the promotion of electric vehicles, their stability control problem has become increasingly important. Four-wheel-drive electric vehicle can not only control the vehicle stability through hydraulic braking pressure regulation, but also through controlling the motor driving and braking force to generate yaw moment , which are different with the conventional vehicles. In addition, the hydraulic braking system of four-wheel-drive electric vehicle is Electro-Hydraulic Braking System (EHB), rather than the conventional hydraulic braking system. With EHB, the braking pressure in four wheel cylinders can be controlled independently and flexibly, rather than depending on the braking pedal. Besides, there are also several pressure sensors in EHB, which can supply the wheel cylinder pressure information, without the need for pressure estimation. As a result, the way to achieve stability control of four-wheel drive electric vehicle will be different with conventional vehicle. Currently, there are not many researches on the stability control of four-wheel-drive electric vehicle with EHB, and most of them are still at the stage of virtual simulation, lacking testing and applications in real system.
Technical Paper
2014-09-28
Alberto Boretti
Real driving cycles are characterized by a sequence of accelerations, cruises, decelerations and engine idling. Recovering the braking energy is the most effective way to reduce the propulsive energy supply by the thermal engine. The fuel energy saving may be much larger than the propulsive energy saving because the thermal engine energy supply may be cut where the engine operates less efficiently and because the thermal engine can be made smaller. The present paper discusses the state of the art of hydro-pneumatic driveline now becoming popular also for passenger cars and light duty vehicle applications.
Technical Paper
2014-09-28
Jongsung Kim, Chjhoon Jo, Yongsik kwon, Jae Seung Cheon, Soung Jun Park, Gab Bae Jeon, Jaehun Shim
Electro-Mechanical Brake (EMB) is the brake system that is actuated by the electrical energy and the motor rotation. It has similar design with Electro-Mechanical Parking Brake (EPB). It uses the gear multiplication structure for the enough torque and screw/nut mechanism for changing rotational movement to linear. The differences with EPB are screw/nut and motor type and some specification of the inner parts because the needed performance of the service braking like braking time is much higher than EPB, and usually EMB includes the force sensor for controlling the actuator and solenoid-lever structure for EPB function. The highly responsive and independent brake actuators lead to enhanced controllability which should result in not only better basic braking performance, but also improvements in various active braking functions such as integrated chassis control, driver assistance systems, or cooperative regenerative braking. Although the EMB system has the potential for numerous advantages and innovations in braking, it has yet to be successfully introduced in series production mainly due to safety and cost concerns.
Technical Paper
2014-09-28
Klaus Augsburg, Dzmitry Savitski, Lukas Heidrich, Valentin Ivanov
The presented study discusses design of brakes and brake control system for all-wheel drive electric vehicle equipped with individually controlled in-wheel motors (IWM). Initial part of the paper is dedicated to the analysis of different packaging of wheel brakes to be mounted together with IWM in the wheel hub. Special attention is given to the implementation of perimeter brake setup. Parameterization and design of specific perimeter brake configuration is introduced. The second part of the paper introduces advanced strategies for brake blending and ABS control. The proposed strategy of blending control realizes brake force distribution targeting the increase of regenerative braking with taking into account the limitations placed by the IWM operation. The ABS architecture is based on the direct slip controller. Its functionality will be illustrated with different case studies investigating the ABS braking with electric motors and hydraulic brake system. The particular attention is also given to the valuation of the brake comfort.
Technical Paper
2014-09-28
Zhizhong Wang, Liangyao Yu, Yufeng Wang, Kaihui Wu, Jian Song, Ning Pan, Liangxu Ma
The Distributed Electro-hydraulic Braking System (DEHB) is a wet type brake-by-wire system for passenger vehicles, and is especially suitable for electric vehicles and hybrid electric vehicles. The basic DEHB comprises four independent brake actuators connected to four hydraulic brakes. The word ‘distributed’ refers to the distributed arrangement of the brake actuators on the vehicle. Each brake actuator comprises an electric motor to provide brake power, a mechanism to translate rotational motion of the motor shaft into translational motion of a piston. The piston moves back and forth in a cylinder under the control of the motor to push the brake fluid into the brake. In this way, braking pressure can be controlled by the motor. Like other brake-by-wire systems, brake pedal simulator and pedal sensors are also used in DEHB. Although the concept of DEHB traces back to 1990s, only a few research papers can be found. This paper gives a review and outlook on the design concepts of DEHB from the following three aspects. 1.
Technical Paper
2014-09-28
Lu Xiong, Bing Yuan, Songyun Xu, Xueling Guang
At the very beginning part, a detailed analysis on current status of electro-hydraulic brake system is carried out. By analyzing 28 electro-hydraulic brake systems, the paper provides a brief summarization on structural components of typical electro-hydraulic brake systems from the perspective of main functional units. Then a more in-depth analysis is conducted on the key functional units, particularly on Active pressure-building unit and Pedal simulation unit. For instance, in terms of Active pressure-building unit, electro-hydraulic brake system schemes can be divided into two categories according to active power sources: one is pump + high-pressure accumulator, the other electric motor+ reducing mechanism. Then author employs MK C1, the latest electro-hydraulic brake system launched by Continental AG, to illustrate its structural components and working principle. In the second part, the idea of dual-motor electro-hydraulic brake system is proposed. As a new solution, dual-motor electro-hydraulic brake system can actively simulate pedal feeling and merge pedal power (from the driver ) into braking power at the same time, which is a distinctive innovation compared to most current electro-hydraulic brake systems.
Technical Paper
2014-09-28
Michael Herbert Putz, Christian Wunsch, Markus Schiffer, Jure Peternel
With linear actuated brakes the actuation force (or actuation torque) rises linearly from 0 to the full actuation force at full braking, causing a very variable motor current. The electro-mechanical brake (EMB) of Vienna Engineering (VE) uses a highly non-linear mechanism to create the high pressing force of the pad. The advantage is that the pad moves very fast when the pad pressing force is low and moves slower with increasing pressing force. This non-linear actuation means that the motor is always running at relatively constant load (although the pad pressing force changes highly), resulting in a motor that can be optimized for constant torque and constant rpm, reducing size and costs and increasing efficiency. The normal force in EMBs is often controlled by observing mechanical deformation to conclude to stress or force, commonly using strain gauges. It causes costs of the gauge itself and attaching them to e.g. the caliper and a sensitive amplifier. The full gauge equipment goes into the safety-related brake control system.
Technical Paper
2014-09-28
Liang Zhou, Chuqi Su
In this paper,a strategy for recovery of braking energy in HEV with EMB is proposed, which is less limited to the performance of the 42V vehicle power supply, compared with the conventional recycling strategy without EMB. In the traditional HEV with 42V vehicle power supply, recovery of braking energy is mainly recycled to the 42V battery, directly. As charging current is too large, or charging time is too long can damage the battery, 42V battery is difficult to recycle braking energy effectively ,especially in complex urban condition with vehicle braking frequently and rapidly. But in HEV with EMB,the recovery transfers to the motor of EMB directly, which is utilized dynamically in the process of vehicle braking. Excess electricity transfers to the energy storage unit if the generator is performing a voltage higher than the required voltage of EMB brake motor, otherwise, the energy storage unit to supplement electricity. The kinetic energy of the HEV turned into electrical energy to EMB timely,rather than being stored statically in this process.
Technical Paper
2014-09-28
Mandeep Singh Walia, Magnus Karlsson, Lars Hakansson, Gaurav Chopra
Mandeep Singh Walia An analysis method to study the potentials in recovering the brake energy from Volvo articulated haulers has been developed. The study is made to find out how and where possible hybrid solutions can be used. The method is based on the mapping of the peak brake power, brake energy and engine energy. The method was developed using adequate signals collected on haulers at three different customer sites. A conceptual study was also carried out concerning the brake energy to understand the actual amount of brake energy that may be stored in the Energy storage systems (ESS). The results indicate that the analysis method developed can map the brake energy generated and also provide an overview of the actual amount of brake energy that can be accumulated in the ESS, which can also guide in an effective selection of the ESS for a particular work site.
Technical Paper
2014-09-28
Kyung-Jung Lee, Jae-Min Kwon, Jae Seung Cheon, Hyun-Sik Ahn
X-by-wire technology replaces mechanical connections with electrical signals, and is indispensable for realizing an intelligent vehicle. The technology has many advantages including reduction of parts, increase in design degree-of-freedom, and safety increase. Especially, the Brake-by-Wire (BBW) system consists of electromechanical actuators and communication networks, instead of conventional hydraulic or electrohydraulic devices, has emerged as a new and promising vehicular braking control scheme. It offers enhanced safety and comfort, cuts off cost associated with manufacturing and maintenance, and eliminates environmental concerns caused by hydraulic systems. The BBW system has recently invoked a lot of interest for both industry and academia worldwide. The FlexRay is an automotive network communications protocol built to be a deterministic, fault-tolerant bus system. It was developed by the FlexRay Consortium as a conjunction with the leading automotive manufacturers. The FlexRay is a new time-triggered communication system for high-performance in-vehicle applications.
Technical Paper
2014-09-28
Ning Pan, Liangyao Yu, Zhizhong Wang, Liangxu Ma, Jian Song, Yongsheng Zhang, Wenruo Wei
With the purpose of individual wheel cylinder pressure regulation and independent of engine vacuum, Brake-by-wire (BBW) systems are suitable for electric vehicles and hybrid electric vehicles. BBW system has been developed in recent years. Electro-Hydraulic Brake (EHB) system is the first step towards BBW system. Various EHB systems have been proposed by researchers. A typical design includes a high pressure accumulator to supply pressure source and pulse width modulated (PWM) solenoid valves to regulate the brake pressure, such as the product of Bosch and Toyota. The electrically driven booster system uses motor to boost driver brake input, such as the system proposed by Mobis. Continental Teves proposed an EHB system with modified ESC hydraulic unit and electric vacuum pump. This paper proposes a new compact EHB system, arming at decreasing the size and cost without compromise of performance. There are there sections in this paper, the first section of which is system configuration and basic operation principles, the second section is the hydraulic pressure control algorithm to regulate the cylinder pressure, and the last section shows the simulation study to verify the performance of the new proposed EHB and its pressure control algorithm.
Technical Paper
2014-09-28
Liangxu Ma, Liangyao Yu, Xuhui Liu, Zhizhong Wang, Ning Pan
The paper is focused on the research of the automotive magneto-rheological brake system whose braking force comes from the shear stress of magneto-rheological fluid under the condition of magnetic field. The MRF brake is designed for a small-sized electric passenger car to replace a conventional hydraulic disc-type brake. The brake disk is immersed in the MRF whose yield stress changes as the applied magnetic field. The braking torque of this system can be linearly adjusted by the current in just a few milliseconds without the conventional vacuum booster. This system has a quick response and precise control performance with a low hysteresis. Besides, the system has adopted the original complicated structure to save space and cost. Nowadays, most of the related research of MRF is about the construction of the prototype and the realization of the brake force. However, due to a lack of optimal design and the understanding of MRF, the main research progress is only about the simulation and the braking effect of the prototype can hardly meet the requirement of the vehicle braking.
Technical Paper
2014-04-01
Robert Lloyd
Abstract A hydro-mechanical transmission is described that approximates the “gearing” performance of a continuously variable transmission and incorporates all functions required for hydraulic regenerative braking. Other characteristics such as efficiency, noise, and responsiveness, match or exceed that of present day conventional automatic transmissions. Performance and physical sizing are shown for passenger vehicle, bus and truck transmissions.
Technical Paper
2014-04-01
Jiageng Ruan, Paul Walker
Abstract Regenerative braking energy recovery bears significance in extending the driving mileage of electric vehicles (EVs) while fulfilling real-time braking demands. Braking energy strategy plays a significant role in improving the regenerative braking performance and ensuring braking safety. This paper presents a regenerative braking energy recovery strategy for an example EV with a two-speed Dual Clutch Transmission (DCT). The two-speed DCT, with simple structure, can effectively extend the active vehicle speed-range for regenerative braking. Meanwhile, a shifting strategy is proposed for the DCT, working with the presented braking energy recovery strategy, to optimize the brake force distribution between front and rear wheels, motor and friction brake force. The EVs' model with the proposed regenerative braking strategy and the optimal shifting schedule was established and implemented in Matlab/Simulink. A testing rig based on an example EV was then set up in our laboratory to experimentally validate the proposed strategy.
Technical Paper
2014-04-01
Rong He, Hongyu Zheng, Changfu Zong
Abstract In order to improve the braking energy recovery and ensure the braking comfort, a new type of regenerative braking coordinated control algorithm is designed in this paper. The hierarchical control theory is used to the regenerative braking control algorithm. First, the front axle braking force and rear axle braking force are distributed. Then the rear axle motor braking force and mechanical braking force are distributed. Finally, the dynamic coordinated control strategy is designed to control pneumatic braking system and motor braking system. Aimed at keeping the fluctuation of the total braking force of friction and the regenerative braking force small during braking modes switch, a coordinated controller was designed to control the pneumatic braking system to compensate the error of the motor braking force. Based on Matlab/Simulink platform, a parallel hybrid electric bus simulation model with electric braking system (EBS) was established. Then the simulation in different operating conditions was used to analyze the braking energy utilization and the braking performance based on the simulation model.
Technical Paper
2014-04-01
Masayuki Naito, Yasuhiro Koike, Shintaro Osaki, Shinichiro Morishita, Nanhao Quan
Abstract HEV and EV markets are in a rapid expansion tendency. Development of low-cost regenerative cooperation brake system is needed in order to respond to the consumers needs for HEV and EV. Regenerative cooperation brake system which HEV and EV are generally equipped with has stroke simulator. We developed simple composition brake system based on the conventional ESC unit without the stroke simulator, and our system realized a low-cost regenerative cooperation brake. The key technologies are the quiet pressurization control which can be used in the service application, which is to make brake force depending on brake travel, by gear pump and the master cylinder with idle stroke to realize regenerative cooperation brake. Thanks to the key technologies, both the high regenerative efficiency and the good service brake feeling were achieved.
Technical Paper
2014-04-01
Zhiting Zhu, Lu Xiong, Chi Jin
Abstract The control in transient conditions when hydraulic brake and regenerative brake switch mutually is the key technical issue about electric vehicle hybrid brake system, which has a direct influence on the braking feel of driver and vehicle braking comfort. A coordination control system has been proposed, including brake force distribution correction module and motor force compensation module. Brake force distribution correction module has fixed the distribution results in hydraulic brake force intervention condition, hydraulic brake force evacuation condition and regenerative brake force low speed evacuation condition. Motor compensation module has compensated hydraulic system with motor system, which has fast and accurate response, thus the response of whole hybrid system has been improved. Simulation results in transient conditions show that the coordination control strategy can effectively reduce the fluctuations and deviations of total brake force, and improve braking feel of driver and vehicle braking comfort.
Technical Paper
2014-04-01
Li Sun, Mohamed Awadallah, Lianhua Chi, Nong Zhang
Abstract This paper presents a smart electric scooter system consisting of a microprocessor based vehicle controller (integrating an embedded regenerative braking controller), a 300W Permanent Magnet (PM) DC motor, two low-power DC-DC converters to form a higher power DC-DC converter pack, a motor controller, a supercapacitor bank and a capacitor cell balancing sub-system. During acceleration or forward motoring mode, the vehicle controller sets the DC motor into motoring mode to further utilizing motor controller regulate wheel speed and acceleration torque, whereas during deceleration or forward braking mode, sets the DC motor into braking mode and further utilizing regenerative braking controller regulate wheel speed and braking torque, as well as functions as a constant current (whose reference value is adjustable via a potentiometer) generator to charge the supercapacitor bank in a controllable fashion, hence not only successfully replacing frictional braking to certain degree, but also increasing the total energy efficiency dramatically owing to the low internal resistance and larger capacitance of the supercapacitor compared with other conventional regenerative braking systems via batteries.
Technical Paper
2014-04-01
Takao Suenaga, Takahiro Jo
Abstract The automotive industry is placing high importance on technologies that can reduce CO2, even in a highly fuel-efficient compact car. One major technology is Stop & Start(S&S) System, with a combined energy regeneration system. A key component of the system is a power supply storage device that has high-charge acceptance, light weight, and compact size. We believe a Lithium-ion (Li-ion) battery completely meets these requirements. For the battery, there are three key points: 1 Battery cell specification2 State Of Charge (SOC) detection method3 Temperature management for Li-ion battery. We have already proposed the battery cell and the SOC detection during SAE 2013, and now we are going to introduce “Temperature Management”. If the temperature of a Li-ion battery operates over 60 degrees Celsius, the battery could be severely damaged. Therefore, temperature management of the battery is very important. Conventionally, the temperature is managed by several thermistors and a cooling fan.
Technical Paper
2014-04-01
James Gramling
Abstract It is very important to note that most present-day CVT's drive with a friction element. Unlike gears that can be produced with any size necessary for the torque load they must transfer, CVT's are limited in torque capacity and are only marginally suitable for small vehicle applications. A system is described using two variable-inertia flywheels to not only supply the heavy torque requirements during acceleration of a vehicle but also operate in reverse capturing the otherwise wasted decelerating torque (I.E. braking torque). This system (called Kinetic Energy Power Transmission System or KEPTS) provides all of the documented benefits of the use of an IVT for motor vehicle acceleration and also incorporates regenerative braking. The significance of the system is that besides providing a complete KERS (kinetic energy recovery and storage) system, all accelerating and braking torque is provided by the two variable-inertia flywheels, thus allowing the main motive engine (ICE, electric traction motor, gas turbine, etc.) to operate at a fixed angular velocity (rpm) isolated from large torque variances, and the CVT elements can be minimized in size (I.E. low-torque).
Technical Paper
2014-04-01
Haohua Hong, Lifu Wang, Minyi Zheng, Nong Zhang
This paper employs the motion-mode energy method (MEM) to investigate the effects of a roll-plane hydraulically interconnected suspension (HIS) system on vehicle body-wheel motion-mode energy distribution. A roll-plane HIS system can directly provide stiffness and damping to vehicle roll motion-mode, in addition to spring and shock absorbers in each wheel station. A four degree-of-freedom (DOF) roll-plane half-car model is employed for this study, which contains four body-wheel motion-modes, including body bounce mode, body roll mode, wheel bounce mode and wheel roll mode. For a half-car model, its dynamic energy contained in the relative motions between its body and wheels is a sum of the energy of these four motion-modes. Numerical examples and full-car experiments are used to illustrate the concept of the effects of HIS on motion-mode energy distribution. The obtained simulation results show that the installed HIS system is able to reduce the energy level in the body-dominated roll motion-mode, and it has negligible effect in the bounce mode.
Technical Paper
2014-04-01
Chen Lv, Junzhi Zhang, Yutong Li, Ye Yuan
Abstract Regenerative braking, which can effectively improve vehicle's fuel economy by recuperating the kinetic energy during deceleration processes, has been applied in various types of electrified vehicle as one of its key technologies. To achieve high regeneration efficiency and also guarantee vehicle's brake safety, the regenerative brake should be coordinated with the mechanical brake. Therefore, the regenerative braking control performance can be significantly affected by the structure of mechanical braking system and the brake blending control strategy. By-wire brake system, which mechanically decouples the brake pedal from the hydraulic brake circuits, can make the braking force modulation more flexible. Moreover, its inherent characteristic of ‘pedal-decouple’ makes it well suited for the implementation in the cooperative regenerative braking control of electrified vehicles. With the aims of regeneration efficiency and braking performance, a regenerative braking control algorithm for electrified vehicles equipped with a brake-by-wire system is researched in this paper.
Technical Paper
2013-11-27
Alberto Boretti
Kinetic energy recovery systems (KERS) placed on one axle coupled to a traditional thermal engine on the other axle is possibly the best solution presently available to dramatically improve the fuel economy while providing better performances within strict budget constraints. Different KERS may be built purely electric, purely mechanic, or hybrid mechanic/electric differing for round trip efficiency, packaging, weights, costs and requirement of further research and development. The paper presents an experimental analysis of the energy flow to and from the battery of a latest Nissan Leaf covering the Urban Dynamometer Driving Schedule (UDDS). This analysis provides a state-of-the-art benchmark of the propulsion and regenerative braking efficiencies of electric vehicles with off-the-shelve technologies. While the propulsion efficiency approaches 90%, the round trip regenerative braking efficiency reaches the 70%, values previously achieved only with purely mechanical systems, few percentage points below the round trip efficiencies of todays' best mechanical system.
Technical Paper
2013-10-15
Takahiro Noyori, Setsuko Komada, Hirobumi Awakawa
Our new technology, the first technology in the small vehicle industry, achieves the fuel economy improvement due to the electricity through the highly efficient electricity generation and charge by the regenerative braking energy obtained during vehicle decelerating or coasting. The newly developed technologies is the regenerative braking system, which minimizes electricity generation during vehicle driving, while maximizes it during vehicle decelerating or coasting. Regenerative braking is the function to generate electric power using with the regenerative braking energy obtained during vehicle decelerating or coasting through the accelerator pedal released or the brake pedal applied. The kinetic energy from the vehicle in motion is recaptured as the electric power to be used for the electric component operation. This system includes the combination of the highly efficient lithium-ion battery in addition to the lead-acid battery for ISS (Idling Start and Stop) application and highly efficient alternator with higher output performance.
Technical Paper
2013-10-14
Satya Kaul, Jaideep Gupta, Shubham Sharma, Naveen Kumar
It is of common knowledge that tapping all the feasible sources of energy and systems which prevent losses is the need of the hour. Currently, many such systems have been developed including “REGENERATIVE BRAKING”. The usual method for regenerative braking includes using a dynamo attached to the crankshaft which gets charged when the wheel rotates during idling. However, this study aims at doing this differently by attaching the regenerative system at the wheels. Considering an example of wastage of energy, a 1000 kg car brakes from 36km/h (10m/s) to 18km/h (5m/s) about 150 times in a liter consumption of diesel. We can safely calculate wastage of 5625 KJ of kinetic energy. This paper aims to explore this immense potential source of energy recovery by producing & storing electricity using magnetic braking on wheels of automobiles. Also, the location of the magnetic braking system ensures that the heat produced is dissipated fast enough, which is unlike conventional regenerative braking.
Technical Paper
2013-10-07
Fabio Mazzariol Santiciolli, Jony Javorski Eckert, Eduardo Dos Santos Costa, Heron José Dionísio, Franco Giuseppe Dedini
The purpose of this paper is evaluating the amount of kinetic energy available to be regenerated by a hybrid electric vehicle (HEV) undergoing the Brazilian standardized driving cycle. Improvements on energy efficiency of the cars has become an urgent target of the Brazilian industry since Brazil launched a new automotive regulation imposing the reduction of 15.5% on the fuel consumption of the vehicles to be sold in this country in 2017 comparing to 2011. The HEVs are a possible solution for this situation. They are widely known by the high efficiency, mainly the ones capable to make the regenerative breaking, rescuing an already paid energy. Before the launch of HEVs in Brazil, the feasibility of these vehicles has to be accurately studied and one aspect to be evaluated is how much energy is possible to be rescued in the Brazilian standardized driving cycle. In this paper, a longitudinal vehicle dynamic model is implemented using MATLAB/Simulink® in order to demonstrate the energy balance of longitudinal dynamics of a popular Brazilian car subject to the driving cycle cited before, highlighting the energy available for regeneration.
Technical Paper
2013-09-30
Rayad Kubaisi, Konrad Herold, Frank Gauterin, Martin Giessler
Electric driven Vehicles (EV) can help reduce CO2 emissions caused by traffic. High acquisition costs and the limited driving range of electric vehicles are their major drawbacks. In the last few years many efforts in research have been made to increase the usability of EV's. A Battery Electric Vehicle (BEV) consists mainly of an electric motor and a battery. Both components allow regenerative braking, where kinetic energy can be transformed back to electric energy and stored in the battery during braking. Several types of Regenerative Braking Systems (RBS) already exist. These systems differentiate from each other by the concepts and strategies used, and therefore have different potential to increase the driving range of electric driven vehicles. Furthermore, the potential depends on the actual traffic situation and the actual state of the vehicle components. In this paper, a review of the actual concepts proposed for regenerative braking and their impact on driving range will be made.
Technical Paper
2013-09-30
John Robinson, Tarunraj Singh
Linked front and rear braking systems are difficult to implement properly on motorcycles due to the large changes in wheel loading under braking. At the braking limit, there is little to no load on the rear wheel and any brake torque could lock it, making the vehicle laterally unstable. Therefore, most motorcycles have independent controls for the front and rear brakes, requiring the rider to balance the brake force distribution. Electric motorcycles have the ability to utilize the drive motor to apply braking torque at the rear wheel. In this paper a control technique has been developed to link rear wheel braking torque to the front brake lever without risking rear tire lock. Thereby, it is also possible to recapture the energy from rear wheel braking. The control strategy has been tested on a transient pitch model, with rotating wheels and tire model data. It has been found that the control strategy provides significant reduction of stopping time and distance when compared to only using the front brake, while maintaining lateral stability of the motorcycle and not requiring any additional effort from the rider.
Technical Paper
2013-09-24
Mohamed H. Zaher, Sabri Cetinkunt
This paper focuses on embedded control of a hybrid powertrain concepts for mobile vehicle applications. Optimal robust control approach is used to develop a real time energy management strategy. The main idea is to store the normally wasted mechanical regenerative energy in energy storage devices for later usage. The regenerative energy recovery opportunity exists in any condition where the speed of motion is in the opposite direction to the applied force or torque. This is the case when the vehicle is braking, decelerating, the motion is driven by gravitational force, or load driven. A rule based control algorithm is developed and is tuned for different work cycles and might be linked to a gain scheduling algorithm. A gain scheduling algorithm identifies the cycle being performed by the work-machine and its position via GPS, and maps both of them to the gains.
Technical Paper
2013-04-08
Junzhi Zhang, Chen Lv, Xiaowei Yue, Mingzhe Qiu, Jinfang Gou, Chengkun He
As one of the key technologies of electrified vehicles, regenerative braking offers the capability of fuel saving by converting the kinetic energy of the moving vehicle into electric energy during deceleration. To coordinate the regenerative brake and friction brake, improving regeneration efficiency and guaranteeing brake performance and brake safety, development of special brake systems for electrified vehicles is needed. This paper presents a new type of electrically-controlled regenerative braking system (EABS) that has been developed for electrified passenger vehicles, which has the potential to be brought into production in China. By utilizing as much as possible mature components, integrating cooperative regeneration with ABS/TCS functions, EABS can achieve high regeneration efficiency and brake safety while providing system reliability, low development cost and development risk. This article describes the layout of the newly developed regenerative braking system. The operation modes and control methods of the system are introduced.
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