AKRO-B – a modern monitoring and diagnostics system designated for remote state monitoring for running gears of rolling stock, transmission and registration of information on their characteristics at the nearest car service point (PTO).

Main functions of AKRO-B

  • automatically determining alarm levels – “Alarm 0”, “Alarm 1”, “Alarm 2” depending on ambient temperature;
  • automatically assessing state of an axle box not only by its case temperature, but also by each axle box’s case temperature exceeding the average temperature value of axle boxes’ cases of a carriage of a corresponding train side;
  • determining a movable unit type at a train passage rate and assessing state of axle boxes of a locomotive and carriages by threshold values established for corresponding movable units;
  • continuously diagnostically monitoring AKRO-B equipment with transmission and display of all diagnostic information to an automated workstation (АRM) of an operator of the nearest car service point (PTO);
  • determining instantaneous speed for each axle of a passing train;
  • remotely controlling (from ARM PTO) span equipment (switching on heating of input windows of trackside chambers, changing threshold levels – “Alarm 0”, “Alarm 1”, “Alarm 2”, calibrating measuring chambers, etc.);
  • accumulating and storing information on trains having passed a monitoring zone in case of a communication channel failure with transmitting information after its restoration;
  • dialogue testing and adjusting AKRO-B using an indicator and control console with a graphic liquid-crystal display, the console is built into a span equipment controlling rack;
  • monitoring power supply feeders, automatically switching a system to an operable backup power supply feeder, switching to power supply from accumulator batteries in case both power supply feeders fail;
  • possibility to connect security and fire alarm.

Composition of AKRO-B basic system

  • The basic AKRO-B system includes span (trackside and tower) equipment of a line control station (LPK) and station equipment.
  • The field equipment includes four infrared measuring chambers for remote measurement of temperature of axle boxes’ cases and detection of braked wheel pairs. For each measuring chamber, an own wheel detection sensor is stipulated for time synchronization of measurements. Additionally, two wheel detection sensors are used at the starting and ending boundaries of the monitoring zone.
  • The tower equipment is an accumulation and processing device in a cabinet construction located at a distance up to 30 m from measuring chambers of the field equipment.
  • The station equipment is a PS5150 workstation combining functions of a server and ARM PTO. It is located in a room of PTO or assistant station master.

System advantages

  • Cost and labour saving during equipment installation due to:
  • fastening the field equipment to a rail base on clamps without drilling, welding, or foundation laying;
  • excluding the chamber positioning procedure;
  • installing the tower equipment into existing structures or into a transportable module;
  • Cost and labour saving during equipment operation due to:
  • automating the calibration process for temperature measuring channels;
  • automatically keeping the optimum temperature of a sensitive layer of infrared radiation receivers;
  • Life increase for a measuring chamber due to minimization of active operation time of mechanical elements;
  • It is not required to reduce and maintain constant train speed;
  • Possibility to be included into a centralized system for automatic remote monitoring of technical state of movable units (within a certain railway or the whole railway network).

Additionally, on customer’s request, equipment with the following functions is supplied within AKRO-B:

  • detecting tread wheel defects;
  • monitoring dimensions of movable units and availability of dragged objects;
  • automatically individually identifying each movable unit using RF-marks;
  • dynamically weighting, fixing load distribution to axles (wheels), etc.

Field equipment

UNO-5 tower equipment

ARM of an operator


Structure of AKRO-B

Main technical characteristics



 Speed range of monitored trains

 from 1 to 160 (freight ones) and up to 350 km/h (passenger)

 Quantity of movable units in a train

 not more than 200 pcs.

 Quantity of axles in a train

 not more than 1600 pcs.

 Minimum time interval between two trains passing the monitoring zone

 2 min

 Maximum quantity of trains passing the monitoring zone per 24 hours

 250 pcs..

 Operation readiness time after supplying power voltage

 not more than 10 min

 Information transmission range

 not more than 30 km

 Monitored temperature range for axle boxes’ cases from the ambient temperature to +120 °C, error 

 not more than 2 °C

 Monitored temperature range for wheel disks from +150 to +550 °C, error

 not more than 12 °C

 Error of ambient temperature monitoring

 not more than 1°C

 Detection probability for overheated axle boxes

 not less than 98 %

 Detection reliability for overheated axle boxes

 not less than 96 %

 Average lifetime

 not less than 10 years

SRPA “Impulse” is a leading Ukrainian designer, manufacturer, and supplier of highly-reliable instrumentation and control systems for nuclear power engineering and railways.
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