Electronically Controlled Pneumatic Brake System Emulator Development

Migration of the vehicle fleet from the current, pneumatic-only, automatic air brake (AAB) system to ECP presents a significant challenge due to the systems’ inherent operational incompatibility. This project will investigate the feasibility of devices that can help to ease this transition by allowing ECP equipped cars to operate in a conventionally braked train, as well as devices to permit conventional cars to operate in an ECP train. An emulator device, applied to a stand-alone ECP car, acts in conjunction with the car’s ECP components to emulate the functions of a conventional pneumatic control valve. The control valve emulator monitors local brake pipe pressure and interprets the pressure fluctuation signals to obtain brake application and release commands. These commands are then communicated to the ECP car control device (CCD) via the electrical train line using standard ECP train brake commands. The CCD functions in its normal manner to control brake cylinder pressure. The emulator also generates other messages required for proper operation of the CCD, such as the head end unit beacon. In addition, the emulator provides the control valve features that help to propagate pneumatic signals in the brake pipe, such as quick service, accelerated application, and accelerated release.