Braking systems have also become conduits to energy storage with the demanding energy and energy management needs, including better fuel efficiency for customers. Until recently, braking systems were exclusively the safety devices in vehicles. Even today, their intended purpose in a vehicle is being done in terms of providing braking, manoeuvring on different terrains through electronic stability control and reassuring this to the occupants irrespective of the powertrain and type of vehicle, and the region of the world. This trend is changing in the high demands of vehicle energy needs.
In unison, the sensors, materials, electronics and software with architectures have progressed to match the changing ecosystem needs, regulatory norms and changing infrastructure. The weight reduction actions have been deployed liberally to ensure that this reduction contributes to fuel economy enhancement of vehicle platforms. Standardisation of sizes, materials, sensors and other components has been implemented as well, to ensure economies of scale for lower cost impact. It also reduces turnaround ordering time and creates tremendous efficiencies in the system.
In terms of being energy conduit devices, braking systems are extensively used in hybrid vehicles for regenerative braking. The vehicle system controller taps into the brake controllers and the system to capture energy while braking, which would have been lost as thermal energy. This energy is stored in the batteries or any other energy storage device. The interesting aspect of the energy diversion and storage process is the sizing and architecture of the hybridisation.
With the R&D efforts in autonomous driving vehicles, especially in e-mobility platforms, needs of the braking system and the industry orientation changes completely. The range of vehicles, the architectural strategy, battery sizing and the smarts in the system are highly influencing attributes. In most of the technology demonstrators of autonomous driving, occupants no longer have a direct control on vehicle speed or steering of the vehicle. This creates new situations since the vehicle systems controllers are not getting accelerator or brake pedal input any more. The rate of movement of the pedals or pedal commands is no longer the deciding factor for the rate of braking. The visual sensors using smart devices activate braking of the vehicle and manage speed of vehicle based on the operational environment of the vehicle. In reality, in autonomous driving the driver relinquished attention to the road and control of their vehicle, so the braking systems and redundancies must be built to mitigate actions against the failure of other systems.
Without a driver in autonomous vehicles, the requirements of reliability specifications for the systems increase significantly. Today’s vehicles are designed inherently to be fail-safe. If one component in today’s braking ecosystem fails, it falls into a safe state. However, autonomous vehicles will have to be fail-operational, so that even if one component fails, the automated vehicle systems continue to operate.
As regulatory norms are being put in place – and some of them are already in place – it could develop in the direction of the aircraft industry, where braking systems redundancy in auto pilot mode is already in place. Many aircraft systems have become mass market automotive solutions in the past. SAE standards committee, in the meanwhile, has outlined six different states of driving automation to build these systems and corresponding regulations.
Braking systems and technologies are progressing faster than many other systems in the vehicle industry due to autonomous driving and automated systems. Consumers and OEMs will see a swift change in the vehicles, the operating environment and related ecosystem. To be sustainable, braking systems innovations will have to be pragmatically integrated and cost effective in our lifestyles.