Ko J.,Sungkyunkwan University |
Ko S.,Sungkyunkwan University |
Son H.,Sungkyunkwan University |
Yoo B.,Hyundai Kia Randnter |
And 2 more authors.
IEEE Transactions on Vehicular Technology | Year: 2015
In this paper, a brake system for an automatic transmission(AT)-based hybrid electric vehicle (HEV) is developed, and a regenerative braking cooperative control algorithm is proposed, with consideration of the characteristics of the brake system. The brake system does not require a pedal simulator or a fail-safe device, because a hydraulic brake is equipped on the rear wheels, and an electronic wedge brake (EWB) is equipped on the front wheels of the vehicle. Dynamic models of the HEV equipped with the brake system developed in this study are obtained, and a performance simulator is developed. Furthermore, a regenerative braking cooperative control algorithm, which can increase the regenerative braking energy recovery, is suggested by considering the characteristics of the proposed hydraulic brake system. A simulation and a vehicle test show that the brake system and the regenerative braking cooperative control algorithm satisfy the demanded braking force by performing cooperative control between regenerative braking and friction braking. The regenerative braking cooperative control algorithm can increase energy recovery of the regenerative braking by increasing the gradient of the demanded braking force against the pedal stroke. The gradient of the demanded braking force needs to be determined with consideration of the driver's braking characteristics, regenerative braking energy, and the driving comfort. © 2014 IEEE.
Song M.,Sungkyunkwan University |
Oh J.,Sungkyunkwan University |
Kim J.,Hyundai Kia Randnter |
Kim Y.,Hyundai Kia Randnter |
And 2 more authors.
Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering | Year: 2014
In this paper, an electric oil pump control algorithm for an automatic-transmission-based hybrid electric vehicle was proposed. Dynamic models of the hybrid electric vehicle powertrain and hydraulic control system, including a mechanical oil pump and an electric oil pump, were obtained, and a hybrid electric vehicle performance simulator was developed. Also, a flow consumption model of the hydraulic control system was constructed. To represent the characteristics of the hydraulic control system according to the change in the temperature of the automatic transmission fluid, a viscosity index concept was introduced. Based on the simulation and test results, a viscosity index-line pressure-electric oil pump power map was proposed to describe the power supply requirement according to the viscosity index and the required line pressure. Using the viscosity index-line pressure-electric oil pump power map, an electric oil pump control algorithm was suggested to control the electric oil pump by using multi-stage power for a given viscosity index. The mechanical oil pump speed at which the electric oil pump is turned off was obtained on the basis of the flow consumption model. The electric oil pump control algorithm was evaluated by experiments and simulations. The proposed electric oil pump control algorithm satisfied the target line pressure requirement according to the viscosity index. In addition, an electric oil pump control strategy during an automatic transmission gear shift was suggested for the situation in which the maximum line pressure required for the gear shift cannot be achieved by only the mechanical oil pump. The electric-oil-pump-assisted power was determined from the flow consumption model and the mechanical oil pump speed considering the gear shift. The simulation results confirmed that the electric oil pump control strategy satisfied the maximum line pressure during a gear shift. © IMechE 2013.
Ko J.W.,Sungkyunkwan University |
Ko S.Y.,Sungkyunkwan University |
Kim I.S.,Hyundai Kia Randnter |
Hyun D.Y.,Hyundai Kia Randnter |
Kim H.S.,Sungkyunkwan University
International Journal of Automotive Technology | Year: 2014
This paper presents a regenerative braking co-operative control algorithm to increase energy recovery without wheel lock. Considering the magnitude of the braking force available between the tire and road surface, the control algorithm was designed for the regenerative braking force at the front wheel and friction braking force at the rear wheel to be increased following the friction coefficient line. The performance of the proposed regenerative braking co-operative control algorithm was evaluated by the hardware in the loop simulation (HILS) with an electronic wedge brake on its front wheels and an electronic mechanical brake on its rear wheels. The HILS results showed that a proper braking force on the front and rear wheels on a low μ road prevented the lock of the front wheels that was connected to the motor, and maintained the regenerative braking and increased energy recovery. © 2014 The Korean Society of Automotive Engineers and Springer-Verlag Berlin Heidelberg.
Song M.,Sungkyunkwan University |
Choi S.,Sungkyunkwan University |
Min G.,Sungkyunkwan University |
Kim J.,Hyundai Kia Randnter |
Kim H.,Sungkyunkwan University
2013 World Electric Vehicle Symposium and Exhibition, EVS 2014 | Year: 2014
A battery charging control using a driving motor is proposed for an AT based parallel HEV. To charge the battery using the driving motor, a 2-clutch system control is proposed which uses the engine clutch and the clutch inside the transmission. The battery charging efficiency is estimated from the engine fuel consumption and efficiency of the power electronics. To evaluate the performance of the suggested battery charging control, HEV performance simulator is developed and simulations are performed for FTP-72 mode. Simulation results show that battery charging using the driving motor has a higher charging efficiency and faster charging speed compared with the conventional battery charging system using the ISG. © 2013 IEEE.
Jo C.-H.,Sungkyunkwan University |
Lee S.-M.,Sungkyunkwan University |
Song H.-L.,Shin Ansan University |
Cho Y.-S.,Daemyung Engineering Company |
And 3 more authors.
Proceedings of the Institution of Mechanical Engineers, Part D: Journal of Automobile Engineering | Year: 2010
An electronic wedge brake (EWB) uses the wedge principle to provide a self-reinforcement mechanism, resulting in reduced current to the actuation motor. However, this mechanism can lead to an unstable open-loop system. In this study, an upper-wedge moving-type EWB is developed and a control algorithm is proposed to follow the target clamping force and to prevent jamming of the EWB system using the push-pull control of the actuator. The performance of the EWB is evaluated using a dynamometer and a simulator. Based on testing and simulation, the clamping force and braking time of the proposed EWB are shown to be satisfactory with respect to the required braking deceleration.
Her H.,Seoul National University |
Yi K.,Seoul National University |
Suh J.,Hyundai Kia Randnter |
Kim C.,Hyundai Kia Randnter
IFAC Proceedings Volumes (IFAC-PapersOnline) | Year: 2013
This paper describes an investigation into coordinated control of electronic stability control (ESC), continuous damping control (CDC) and active roll control system (ARC). The coordinated control is suggested to improve the vehicle stability and agility features by yaw rate control. At first, the relation of roll moment distribution and yaw dynamics is analyzed based on simplified tire model. The proposed integrated chassis control algorithm consists of a supervisor, control algorithms, and a coordinator. The supervisor monitors the vehicle status and determines desired vehicle motions such as a desired yaw rate and desired roll motion based on control modes to improve vehicle stability. According to the corresponding the desired vehicle dynamics, the control algorithm calculated a desired yaw moment and desired roll moment, respectively. Based on the desired yaw moment and the desired roll moment, the coordinator determines the brake pressures, the ARC motor torques and damper current based on control strategies. The ARC motor torque has been calculated to generate the roll moment and yaw moment simultaneously. Closed loop simulations with a driver-vehicle-controller system were conducted to investigate the performance of the proposed control strategy using CarSim vehicle dynamics software and the integrated controller coded using Matlab/Simulink.
Kwon C.,Hyundai Kia Randnter |
Lee C.W.,Hyundai Kia Randnter |
Foster L.,Hyundai Kia America Technical Center |
Kwon J.,Hyundai Kia Randnter |
Shin Y.,Sejong University
SAE Technical Papers | Year: 2012
In an electric vehicle, a maximum cruising range is adversely affected by electric power consumption of auxiliary electric components for heating and cooling. Therefore, it is important for the air-conditioning to consume energy as efficiently as possible. This study describes how a proposed Occupied-Zone(OZ) HVAC system has attained a significant increase in the cruising range of an electric vehicle by air-conditioning occupied seats only. The idea of OZ HVAC is to confine air-conditioning to occupied-zones only. The OZ HVAC has an option of selectively air-conditioning three zones corresponding to driver, passenger and rear seating positions, while a conventional HVAC system air-conditions a whole cabin regardless of occupancy in each zone, which results in more power consumption compared to the proposed idea. For example, when a cabin is occupied by a driver only, it is clear that the proposed OZ HVAC limits air-conditioning to the driver zone only and hence less energy consumption for unoccupied zones. The OZ HVAC system has been developed in two steps. The first is modifying existing HVAC hardware so that each zone temperature and air flow rate can be controlled independently with a few additional control doors and the corresponding actuators. The second is to develop a zone temperature control algorithm for the OZ HVAC. Thermal load for a zone, not a whole cabin, was estimated and verified by CFD and vehicle testing. And a new parameter for zonal control was defined as Zonal Energy Efficiency Ratio (ZEER) that represents zonal energy ratio to corresponding steady-state cabin energy consumption. The new energy-saving OZ HVAC system was implemented in BlueOn, the Hyundai electric vehicle. It achieved improvement of 4 to 9 % in a cruising range while maintaining the same level of thermal comfort and reducing the HVAC blower noise compared to the conventional HVAC system. The prototype HVAC is currently under development and testing for further improvement. After its completion of development, the system will be applied to electric vehicles. Copyright © 2012 SAE International.
Youn J.,Hyundai Kia Randnter |
Park I.,Hanyang University |
Sunwoo M.,Hanyang University
International Journal of Automotive Technology | Year: 2013
This paper presents a heuristic resource allocation and scheduling method, which is based on an integrated architecture that enables multiple missions to be embedded in a single electronic control unit (ECU) and a single mission to be distributed over multiple ECUs. The proposed design method is composed of resource(e.g. task and message) allocation, scheduling, and attribute assignments. From a given target application's task graph, the method generates a scheduling table specifying the release, start, and completion timings of tasks and messages. After that, all relevant attributes(e.g. priority of tasks and messages) are automatically assigned. In order to guarantee the functional and temporal requirements of target applications, design constraints such as the worst case response time, deadline, precedence relations, and physical limitations are concurrently considered. A chassis control system consisting of electronic stability control, an electro-mechanical brake, continuous damping control, and electronic air suspension is employed for evaluating the proposed method. The conventional chassis control system which is composed of seven ECUs was redesigned by only four ECUs without the degradation of control performance. Consequently, it is expected that the development time and production cost of distributed automotive control systems can be significantly reduced by the proposed design method. © 2013 The Korean Society of Automotive Engineers and Springer-Verlag Berlin Heidelberg.
Lee D.,Hyundai Kia Randnter |
Perot F.,Exa Corporation |
Ih K.-D.,Hyundai Motor Company |
Freed D.,Exa Corporation
SAE Technical Papers | Year: 2011
Nowadays vehicle quality is rated for noise and vibration and the interior sound levels have become a major target of automotive companies. Strides have been made in reducing power train, tire and external wind noise over the years. However, HVAC and blower fan flow-induced noise reaches the interior cabin without any sound isolation and can strongly impact customer comfort. In the early stage of vehicle design, it is experimentally difficult to get an estimate of the flow pattern and sound levels. The goal of this study is to develop and validate a numerical noise prediction tool for complete HVAC systems noise, defined as the arrangement of sub-systems such as air intake duct, thermal mixing unit, blower, ducts and outlet vents. This tool can then be used during the development of vehicles to evaluate and optimize the aeroacoustics performances of the system without additional or belated experiments. The sound transmission through the dash or wall is not considered in this study and the focus is made on the primarily flow-induced noise contribution. The CFD/CAA numerical method use a time explicit, unsteady and compressible method based on the Lattice Boltzmann Method (LBM) during which flow and acoustics are calculated at the same time. The numerical method is used to estimate the noise from two productive HVAC systems mounted on a Simplified Vehicle Cabin (SVC) and real Production Vehicle Cabins (PVC). Results in term of flow and noise are compared and validated through experiments. The influence of the cabin structural modes and absorption on the broadband noise levels is also discussed. Copyright © 2011 SAE International.
Kang J.,Hyundai Motor Company |
Lee J.,Hyundai Motor Company |
Song H.-S.,Hyundai Motor Company |
Lee D.,Hyundai Kia Randnter
SAE Technical Papers | Year: 2012
For passenger car diesel engines, higher air density or higher boost pressure is essential to enhance power density and meet stringent emission regulations. However, single variable geometry turbines (VGT) are limited to eliminate the inherent drawbacks of turbochargers; low-end torque and rated power are hard to reconcile. With a serial two-stage turbocharger, outstanding power density-rated power of 165kW and low-end torque of 350Nm-was obtained from Hyundai Motor's R2.2l engine. Also, it was possible to maintain the maximum torque of 500Nm evenly from 1250rpm up to 2250rpm. Compared to the current R2.2l engine with a single VGT turbocharger, more than 12% of power density increased. The fuel economy of the two-stage turbocharged engine was slightly better than the current R2.2l engine, which resulted in further reduction of fuel consumption compared to a 3.0l single VGT engine. Vehicle test results also showed that the R2.2l engine with two-stage turbocharger could substitute the 3.0l single VGT engine without any deterioration of drivability. Copyright © 2012 SAE International.