• Journal of Power Electronics
• /
• 제13권4호
• /
• pp.536-545
• /
• 2013

In this study, an integrated motor control algorithm for an in-wheel electric vehicle is suggested. It consists of slip control that controls the in-wheel motor torque using the road friction coefficient and slip ratio; yaw rate control that controls the in-wheel motor torque according to the road friction coefficient and the yaw rate error; and velocity control that controls the vehicle velocity by a weight factor based on the road friction coefficient and the yaw rate error. A co-simulator was developed, which combined the vehicle performance simulator based on MATLAB/Simulink and the vehicle model of CarSim. Based on the co-simulator, a human-in-the-loop simulation environment was constructed, in which a driver can directly control the steering wheel, the accelerator pedal, and the brake pedal in real time. The performance of the integrated motor control algorithm for the in-wheel electric vehicle was evaluated through human-in-the-loop simulations.

• Journal of Drive and Control
• /
• 제18권3호
• /
• pp.8-15
• /
• 2021

A rear axle steering (RAS) system is attached to the rear of medium and large commercial vehicles that transport large cargo. The existing RAS systems are driven by electro-hydraulic actuator (EHA), and most commercialized EHAs consist of electric motors, hydraulic pumps, relief valves, prefill valves and cylinders. The prefill valve required for such EHAs is a type of check valve with extremely low cracking pressure that should not allow RAS to have noise or vibration, and the prefill valve prevents system negative pressure as well as unstable operation. Most papers on this topic rely on experiments to predict valve performance, and theoretically detailed modeling of valves or pipelines is performed, but it is very rare to evaluate hydraulic vibration characteristics by analysing everything from hydraulic pumps to valves comprehensively. In this study, we proposed an experimental circuit that can predict the performance of the prefill valve. The study also analysed the pressure-flow pulsation that is transmitted to the valve through the pipeline, and how the transmitted pressure-flow pulsation affects the valve vibration.

• Journal of Institute of Control, Robotics and Systems
• /
• 제21권7호
• /
• pp.615-620
• /
• 2015

DOB (Disturbance Observer) is an useful control method for estimating the disturbance applied to dynamic systems. Disturbance observer can be used to implement a robust control system to generate a control input for rejecting the disturbance, and it can be also used to estimate the disturbance to obtain information. The system that uses disturbance estimation is investigated for high performance control such as automatic door systems, walking robot and electric power steering system in vehicles. In this paper, a novel disturbance observer which is called disturbance and current observer for estimating load torque in the motor system is proposed. The difference between the DOB for disturbance rejection and DCOB is mathematically verified. Current and angular velocity are required for estimating the load torque of the motor in DOB. However, the DCOB can estimate load torque and current without current sensor. DCOB is designed based on modeling of the motor system. Appropriate Q-filter is selected and the applicability of DCOB is verified by simulation. The estimated disturbance and current of the electric motor can be verified without current sensor, as experiments of the actual motor system.

• The Transactions of the Korean Institute of Power Electronics
• /
• 제18권4호
• /
• pp.367-375
• /
• 2013

The mechanical vibration of a PM synchronous motor at low speeds due to the back emf harmonics may be serious problems in some application such as MDPS(Motor driven power steering), electric vehicles. In this paper, torque ripple reduction for an interior PM synchronous motor including back emf harmonics is proposed. The dq flux linkage harmonics of the permanent magnet are estimated on real time by using the dq currents of the real system and the model of the MRAS observer. Based on the estimated flux linkage harmonics, the dq harmonic currents for reducing the torque ripples are compensated on the dq reference currents. The estimation of the flux linkage harmonics by the MRAS observer and the torque ripple reduction of the proposed algorithm was verified by the simulation and experiment.

• ICROS
• /
• 제21권1호
• /
• pp.31-36
• /
• 2015

운전자에게 편의성을 제공하는 차량의 주행관련 Advanced driver assist system (ADAS)에는 차량의 종방향과 횡방향 운동에 대한 제어기가 요구된다. 횡방향 제어를 위해서는 조향 시스템의 조향각 제어가 요구되는데 최근 구조적으로 간단하고 연비향상, 차량의 중량 감소, 빠른 응답성을 가지고 있는 전기적 파워 조향 (Electric power steering, EPS) 시스템이 자동차 산업에서 널리 사용되고 있다. 차량의 주행관련 ADAS를 사용하여 자율 주행 시 EPS 시스템은 상위 제어기에서 계산된 필요한 조향각을 추종 할 수 있도록 조향 핸들의 각 제어를 해야 한다. 그러나 일반적인 EPS 시스템은 운전자가 조향 핸들에 인가된 토크를 보조해 줄 수 있는 토크를 출력해 준다. 본 논문에서는 이러한 문제를 해결하는 방법들을 설명한다. 먼저 EPS 시스템의 기본 기능에 대해서 설명을 하고, 자율 추행 차량을 위한 조항 핸들의 각 제어를 위한 proportional-integral 제어, 슬라이딩 모드 제어 (Sliding mode control), 관측기 기반 비선형 댐핑 제어(Observer based nonlinear damping control) 등과 같은 다양한 기법의 제어 알고리즘들에 대한 방법들이 고찰되었다.

• Proceedings of the KIEE Conference
• /
• 대한전기학회 2011년도 제42회 하계학술대회
• /
• pp.904-905
• /
• 2011

본 논문에서는 기존의 EPS(Electric Power Steering) 시스템에 IPMSM을 적용하고 속도 및 위치를 검출하기 위하여 Magnetic Position Sensor를 사용하였다. 이�� Magnetic Position Sensor의 신호는 정현파의 출력을 갖지만 고조파의 성분으로 인하여서 파형이 왜곡되고 이러한 파형의 왜곡으로 인해 위치 검출의 오차를 갖게 된다. 본 논문에서는 이러한 오차를 줄이기 위하여 다구찌 기법과 3차원 유한요소법(3D FEM)을 사용하여 고조파를 저감시킬 수 있도록 여러 변수를 변화하여서 최적의 설계를 통하여 실제 실제 센서 출력과 비교하여 자동차 산업 전반에 기여 하고자 한다.

• Proceedings of the KIEE Conference
• /
• 대한전기학회 2001년도 하계학술대회 논문집 B
• /
• pp.904-906
• /
• 2001

This paper presents a magnetic circuit design procedure by using Response Surface Methodology(RSM) to determine initial and detail design parameters for reducing torque ripple in BLDC motor of Electric Power Steering (EPS). RSM is achieved through using the experiment design method in combination with Finite Element Method and well adapted to make analytical model for a complex problem considering a lot of interaction of design variable Moreover, Sequential Quadratic Problem (SQP) method is used to solve the relsulting of constrained nonlinear optimization problem.

• Proceedings of the KIEE Conference
• /
• 대한전기학회 2000년도 하계학술대회 논문집 B
• /
• pp.629-631
• /
• 2000

This paper deals with the design of a inner rotor type Brushless DC (BLDC) motor for Electric Power Steering to reduce the cogging torque. The effect of the design parameters on the characteristic and cogging torque is analyzed by Finite Element Method (FEM). The considered design parameters are as follows : the number of pole and slot. dead-zone and skew angle. and teeth shape. The winding resistance of each motor is calculated and the characteristic curve is derived from considering reactance drop voltage for original model.

• Proceedings of the KIEE Conference
• /
• 대한전기학회 2000년도 하계학술대회 논문집 B
• /
• pp.647-649
• /
• 2000

This paper presents a optimization procedure by using Response Surface Methodology(RSM) to determine design Parameters for reducing cogging torque in BLDC motor of Electric Power Steering (EPS). RSM is achieved through using the experiment design method in combination with Finite Element Method and well adapted to make analytical model for a complex problem considering a lot of interaction of these parameters. Moreover, Sequential Quadratic Problem (SQP) method is used to solve the resulting of constrained nonlinear optimization problem.

• Journal of Auto-vehicle Safety Association
• /
• 제5권1호
• /
• pp.69-74
• /
• 2013

LKAS(Lane Keeping Assistance System) main function is to support the driver in keeping the vehicle within the current lane. Therefore, this system is able to reduce the driver workload with assisting the driver during driving. In this paper, we presented on study for test procedures and evaluation methods of the LKAS. The vehicle test conducted on straight road, left curve, right curve and four different types of lane under various vehicle speeds. This study proposed the LKAS system test procedures and methods that we are able to identify LKAS driving mechanism and performance.