• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1842-1845
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• 2006

본 논문에서는 차량용 전자제어식 주차 브레이크(Electric Parking Brake, EPB) 시스템 제어에 효과적인 제어기를 논의한다. 이를 위하여 EPB 시스템의 동작 요건과 고유 특성을 고려하여 제어 사양을 정하고 이를 만족시키는 세 가지 제어기(Bang-bang, 선형 P, 비선형 P 제어기)를 제안한다. 또한 제안된 제어기들의 특성 및 성능을 과도응답과 강인성 측면에서 분석하였다. 이를 위해 EPB 시스템을 주파수 영역과 시간 영역에서 모델링하고, 설계된 제어기들의 성능을 모의실험을 통해 비교, 검증한다.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.20 no.6
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• pp.751-755
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• 2011

Electric Parking Brake(EPB) is the system operated by electric control actuator. It differs from the mechanical parking brake system which is operated by lever and pedal in need of human power. The EPB system is composed of DC motor, helical and differential epicyclic gear, screw, cables, and sensor. This paper describes about the EPB system mathematically and constructs a modeling of the EPB system using MATLAB/SIMULINK. Especially, SimMechanics library in SIMULINK is used to make each parts of system a module. By made modeling of the friction torque between bolt and nut. Cable tension can be maintained after the motor operating stops.

• Transactions of the Korean Society of Automotive Engineers
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• v.25 no.1
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• pp.19-27
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• 2017

In this paper, a simulator hardware and control design for an electronic parking brake (EPB) are proposed for emergency vehicle braking when the hydraulic break and anti-lock brake systems (ABS) fail to function. EPB systems are designed specifically for park braking and are usually installed on the rear wheels. However, in an emergency situation when all vehicle brake systems fail, the EPB can be utilized to stop the vehicle and track the target slip ratio as the ABS. This paper analyzed the non-linear EBP of the type of motor on caliper (MoC) based on experiments. A simulator hardware is also designed to validate the performance of the designed EPB controller in terms of braking distance and performance in tracking the target slip ratio. Through the experimental analysis, it is confirmed that a sliding mode controller can be applied on a non-linear EPB to track the target slip ratio.

• Proceedings of the KIEE Conference
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• 2006.07d
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• pp.1836-1837
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• 2006

본 논문에서는 차량용 전자제어식 주차 브레이크(Electric Parking Brake, EPB) 시스템의 고장 허용 제어(fault tolerant control)를 위한 고장 안전 기법(fail-safe logic)을 제안한다. 고장 안전 기법의 구현을 위하여 EPB 구동 모터에 흐르는 전류 리플을 측정하여 센서리스 위치 추정을 한다. 추정값과 홀 센서의 출력을 비교하여 잔차(residual)를 발생하고, 이를 이용하여 시스템 내부의 고장을 진단하고 고장 안전 기법을 통하여 전체 시스템의 오작동을 방지한다. 시스템 오작동을 방지하기 위한 고장 안전 기법에 대하여 정의하고 모의실험을 통하여 내부 시스템의 고장이 발생 시 이 기법이 고장을 진단하고 시스템을 안전하게 운영할 수 있음을 확인하였다.

• Transactions of the Korean Society of Automotive Engineers
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• v.17 no.5
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• pp.26-30
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• 2009

In this paper, a robust model based fault detection for varying temperature is proposed, To develop a robust force estimation model, it needs temperature information because the force sensor's output is affected by a temperature variation. If an EPB system does not include a temperature sensor, the model has a much larger error than an EPB system with a built-in temperature sensor. Therefore, the temperature is estimated by using Ohm's law. The force model is applied with a motor current, battery voltage, operation mode, and the estimated temperature to detect a force sensor's abnormal signal fault. The residual is calculated by comparing the value of the measured force and the estimated force. Fault information is collected by using the output of the evaluated residual with the adaptive thresholds. A proposed robust model based fault detection for varying temperature was verified by HILS (Hardware in the Loop Simulation).

• Transactions of the Korean Society of Automotive Engineers
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• v.18 no.4
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• pp.8-17
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• 2010

In this paper, a fault tolerant control against sensor faults of electric parking brake (EPB) is proposed. Fault tolerant control method of EPB system is strongly demanded since sensor faults can endanger a driver's safety. In this paper, a clamp force estimation method is presented using motor's armature current and angular velocity. Clamp force estimation method is applied for fault detection method with parity equations. The goal of the detection method is to detect and identify faults in encoder, current sensor, force sensor, and parking cable. And a switching logic for fault tolerant control against the three sensor faults is suggested. Experimental results show that the proposed force estimation method satisfies the specifications of EPB system. The effectiveness of the fault detection method is validated with experimental results. Although a single sensor fault happens, EPB system with the proposed fault detection method does not develop into a failure on subsystem or system level.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1528-1530
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• 2008

기존의 EPB 시스템에서는 제동력을 측정하기 위하여 hall effect force 센서를 이용하고 있지만, 이 센서는 비싼 가격과, 구조상 장착의 어려움 등의 문제점을 가지고 있다. 본 논문에서는 hall effect force 센서에 비해 저가이며, 기구적인 면에서 단순한 구조를 가지는 전류 센서만을 이용하여, 모터 유도 전류와 각가속도 정보를 획득하고, 이것을 이용하여 EPB 제동력을 추정하는 기법을 제안하고 실험을 통해 검증한다.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.57 no.12
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• pp.2291-2299
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• 2008

Hall effect force sensors have been used to measure clamping force in conventional Electric Parking Brake(EPB) systems. Estimation of clamping force without the sensors has drawn attentions due to mounting space limitations and cost issues. Removing the sensor requires the estimation of the initial contact point where the clamping force is effectively applied to the brake pads. In this paper, we propose how to estimate the initial contact point finding the relation between the angular velocity of an actuator and the initial contact point. For force estimation a look-up table is used as a function of the displacement of parking cable from the initial contact point. The proposed method is validated by experiments. From the experimental results we observe that the proposed method satisfies the specifications. The designed method is also able to estimate clamping force although parking cables are loosened and brake pads are worn out. Applying the proposed method enables manufacturing of low cost EPB systems.

• Proceedings of the KIEE Conference
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• 2008.07a
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• pp.1525-1527
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• 2008

기존 케이블 puller 방식의 EPB 시스템은 제동력을 측정하기 위하여 hall effect force 센서를 이용하고 있다. 그러나 본 논문에서는 hall effect force 센서를 사용하는 대신 모터의 속도를 이용하여 제동력이 가해지는 시점을 결정한 이후 모터의 회전수에 따른 제동력 추정 기법을 제안하고 실험을 통하여 검증한다.