| Title |
A Clamping Force Estimation Method in Electric Parking Brake Systems |
| Authors |
장민석(Jang, Min-Seok) ; 이영옥(Lee, Young-Ok) ; 이원구(Lee, Won-Goo) ; 이충우(Lee, Choong-Woo) ; 손영섭(Son, Young-Sup) ; 정정주(Chung, Chung-Choo) |
| Keywords |
Electric Parking Brake ; Clamping force estimation ; Sensorless control |
| Abstract |
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. |