<div class="section abstract"><div class="htmlview paragraph">Recently, there’s a massive flow of change in the automotive industry with the coming era of electric vehicles and self-driving (autonomous) vehicles. The automotive braking system field is not an exception for the change and there are not only lots of new systems being developed but also demands for researches for optimizations of conventional brake systems fitting to the newly appeared systems such as E-Booster and Electric Motor Brake (EMB) Caliper. Taking the Electric Motor Brake Caliper for example, it is considered as a very important and useful system for autonomous vehicles because the motor actuator of the caliper is much easier to control with ECUs compared to the conventional hydraulic pressure system. However, easy of control is not the only thing that excites brake system engineers. Since the whole actuating mechanism of the brake systems has been changed, engineers now can see some new ways to solve chronic problems in conventional brake systems such as brake residual drag, brake fade and so forth. Brake residual drag can be possibly solved by simply connecting the motor actuator of the caliper to the brake piston so that ECUs can actually control the whole life cycle of brake torque creation and extinction. However, there have to be a few more components needed on top of the fact that its structure inside the brake piston could be much more complex than it used to be and this could cause some side effects as well. With the reasons above, this study illuminates the concept for a way of reducing brake residual drag in the new systems by enhancing the capability of piston roll-back of the caliper without any complex structures. Several test results and CAE analysis are presented and discussed to get a better understanding of the concept.</div></div>

<div class="section abstract"><div class="htmlview paragraph">The history of the brake system for the passenger vehicles is no shorter than that of the automobile itself. With the long history, its performance, efficiency and reliability have been dramatically improved and as a result, even leading brake system suppliers now find it very difficult to come up with breakthrough ideas for further optimization of the current brake systems. In addition, as the powertrain of the vehicles has also been improved, the requirements of the brake system have become much more severe than before, leading to a trend of increasing the system size and weight especially for the parts belong to unsprung mass. In the case of high-end vehicles, the system was further optimized using expensive materials such as ceramic, carbon-fiber, etc. However, most normal vehicles have been developed without any significant changes in the existing systems. This decade-long trend of developing braking parts has seen a big change “electrification of the vehicle”. The electrification of the vehicles represented by Electric Vehicle (EV), Hybrid Electric Vehicle (HEV) and Fuelcell has left room for further weight reduction in the current system as they always accompany with another braking mechanism called “Regenerative braking”. It is a well-known fact that regenerative braking can cover the most of braking equivalent to 0.1g to 0.3g, and the 0.1 - 0.3g deceleration takes a major part in normal brake use. Naturally, brake engineers have shown great interest in the possibility of the regenerative braking, and around 2017, they predicted that conventional brake system would eventually become fail-safe for the electric brake system. Likewise, brake system engineers have begun to recognize the potential for full-scale weight reduction in the conventional brake system using regenerative braking. In this paper, the trend of change in weight of brake parts corresponding to unsprung mass was analyzed using A2mac1’s benchmarking data from 2011 to 2021. The analyzed data includes pure internal combustion engine (ICE) vehicles to hydrogen fuel cell vehicles. This study tries to illuminate the weight trend of the current brake systems and figure out how the electrification of the vehicle has affected the brake systems in terms of system weight.</div></div>