Kelsey-Hayes Company, a subsidiary of TRW Automotive, has developed a modular multi-piston pump electronic stability control (ESC) system with enhanced performance to rapidly build brake pressure independent of vacuum boost from the engine. Traditional brake systems rely on a vacuum booster that is assisted by vacuum from the internal combustion engine. But with the rapid growth of direct injection engine technologies, engine vacuum levels are treading lower.

"In situations where brake pressure may need to be generated and applied rapidly, an enhanced brake system solution would be beneficial in vehicles powered by low vacuum powertrains," says Josef Pickenhahn, vice president, brake engineering for TRW. "Adding a separate mechanical vacuum pump or an electric driven vacuum pump and control unit can be costly and difficult to package, may increase the chance of noise vibration and harshness and require more energy to power the brake system leading to reduced fuel economy." The TRW solution is a modular multi-piston pump based stability control system featuring a six-piston pump configuration. The system delivers a high pressure build rate and is virtually seamless in terms of noise and pedal feedback. It allows for rapid braking in cold start, low-temperature and high-altitude scenarios, and is an ideal solution for advanced systems such as automatic emergency braking when full stopping force is applied independent of the driver.

"TRW's modular multi-piston pump technology adds only a relatively small incremental cost over standard ESC and readies the vehicle for the sophisticated integration of driver assist and brake systems in the future. It is an ideal solution for direct injection gas engines but also works well within traditional gas engine powertrain architectures for premium vehicles," Pickenhahn concludes.