The SMART Sleeper - A Highly-Integrated Rail Condition Monitoring System

A SMART Sleeper network system comprises numerous SMART sleepers along the length of track. Each SMART Sleeper includes a data hub, LoraWan transceiver, power system, and modular sensor array. The SMART Sleeper is a low-cost, mass-producible unit capable of reading data from sensor modules via CANBus and either storing it locally for future forwarding or processing it for transmission via LoraWan. It can construct transmission packets in accordance with LoraWan limitations and requirements, and onboard algorithms are used to compress measurement data into compact salient forms suitable for this purpose. The sensor provision may be altered, reduced or expanded in accordance with the particular needs of the line operator, and it is entirely expected that the mix of sensors between sleepers on the line will be varied and heterogenous. The power system includes provision for ambient energy harvesting in the form of a vertical wind turbine, positioned such that passing trains will provide energising wind to complement pervasive environmental wind in powering the device.

Currently supported sensors include:

• Rail expansion and linear shift using high-precision LVDT extensometers mounted on rail clamps, with 10 um precision

• Rail pitch, roll and buckling measured using rail clamp accelerometers\

• Two sets of rail temperature transducers to be incorporated into the rail clamp

• External environment humidity, temperature and rainfall sensors

• Internal humidity and temperature sensors for inside the sleeper

• Two sets of ballast moisture and temperature sensors for below the rail

• Rolling stock bearing overheat detection via 25 FPS IR camera array

• Rolling stock flat wheel detection via microphone array with FFT processing

• Rail acoustic sensing and transmission, with peak amplitude, decay and frequency detection

• Power system condition measurement

• GPS receiver for self-surveying

This project is supported by the ARCS Group and will be field-tested on working rail lines in early 2026, with expected development of a commercial prototype in 2027. It is expected that this technology will be implemented on three lines in WA and has the potential to save Australia and Australian companies $200M annually.

• Vertical IR range-finding for passing train detection