Development of Regenerative Brake Control Strategy to Remove Brake Rust 2019-01-2125

This study is the development concept of regenerative braking cooperative control to reduce creep groan noise considering fuel efficiency. Creep groan noise is a traditional brake system noise that has been improved with advances in technology such as brake materials, surface treatment and transfer path. However, recently creep groan noise is again an issue in electronic vehicle which applied a drive motor. Generally, creep groan noise frequently occurs when rust occurs on the friction surface of the brake disc and the brake pad is humidified, but it is easily removed by friction braking several times. However, in the case of electric vehicles which applied regenerative braking system, it is hard to remove. In case of electric vehicle, instead of friction braking, most of brake toques are made by motor regenerative braking. Therefore, even if the same conventional brake system and chassis system are applied, the noise level of the electric vehicle is higher than gasoline or diesel vehicle, and the field claim is also higher. To improve the noise, regenerative braking cooperative control logic was developed that detects long-term vehicle parking condition and control the regenerative brake ratio of total driver demand brake toque considering fuel efficiency. Also several tests are proceeded to review the effect of creep groan noise and fuel efficiency.