The proper functioning of automotive brake pads is of utmost importance to ensure the safety of passengers. Therefore, brake pad materials must be chosen with utmost precision and care to ensure their optimal functioning for long durations. Through a thorough literature review, it is found that the materials used currently for this purpose pose multiple discrepancies. Therefore, it is imperative to shift our focus towards nanomaterials, as they are one of the essential novel materials in this field. This study discusses the multiple constituents used in commercial brake pads, their role in improving and stabilizing their operation, and their desired properties to achieve optimal functioning. Parallelly, this study also reviews some of the potential organic and carbon nanomaterials that could prove to provide tough competition to currently utilized materials for brake pad applications. From this review, the major future commercial brake pad materials obtained include the likes of banana peel powder, crab shell powder, coconut fibers, stark corn fibers, metal oxide composites, metal nitride composites, multiwalled carbon nanotubes, and hybrid nanocomposites. These materials are studied on the basis of their performance under high-frictional force applications and analyzed by considering their mechanical, chemical, thermal, and tribological properties. Carbon nanotube-based composites showed improved tribological and braking performances making them more attractive than the materials in commercially available brake pads. In addition to these, the effects of usage of such nanomaterials on the environment and health are reviewed, in order to understand the feasibility of utilization of nanomaterials in automotive brake pad applications. From this analysis, this work suggests that there are a variety of nanomaterials that prove to be capable of automotive brake pad applications and, with further research and technological developments, would prove to be an asset to the automotive brake pad industry.

This study aims to achieve optimal regenerative braking performance in the form of a reduced decline in battery SOC for a BLDC electric machine with peak torque of 10 Nm for use in electric two-wheelers. This is conducted via a comparison of control algorithms based on Direct Look-up table, Fuzzy Logic and their combination with PID control. The whole vehicle model and the energy recovery control strategies are designed using MATLAB Simulink by benchmarking the design with the parameters of the Ola Electric S1. A physical motor-dynamometer test bench is utilised to obtain a complete motor operating range to derive a realistic efficiency map that is used in the model. WLTP Class 2 and NYCC standard drive cycles are implemented for vehicle simulation. Two live-recorded driving patterns are also used to validate the model to analyse the adaptability of the control strategies. After obtaining the required motor speed, torque values and the range by matching the theoretical drive cycle profile, the control strategy is further optimised using the PID auto-tuning toolbox in Simulink. Using physical testbench data, the effect of various regenerative braking control strategies on overall vehicle performance is more accurately realised. The Fuzzy PID control strategy exhibits the most optimal gains in terms of energy recovery for electric two-wheelers, allowing for the highest battery SOC levels of 41.88% and average motor regenerative torque of 7.25 Nm for the standard drive cycles. An analogous trend is observed for the on-road driving pattern as Fuzzy PID provides highest battery SOC and average motor regenerative torque of 48.34% and 7.5 Nm respectively. For the driving scenarios aforementioned, this provides a 17% and 44% increase in SOC respectively when compared to a non-regenerative braking-based system.