Brake blending and retardation coordination

The braking system is a software-and-hardware complex that provides the specified braking characteristics taking into account safety and passenger comfort requirements, and also controls compressed-air preparation equipment.

The braking system comprises:

Electronic brake and pneumatic equipment control units;

Brake controllers with electronic interface;

Pneumatic brake equipment;

Compressor units with drying function;

Anti-skid devices;

Brake system condition sensors.

• Control of train deceleration and braking.
• Monitoring of braking parameters for each car.
• Optimal selection of the ratio of friction and electrodynamic braking, reducing wear of friction pairs.
• Achievement of target deceleration value.
• Maintaining stable adhesion (no wheel slide) individually for each axle and the required braking distance under changing external conditions.
• Ensuring safety in abnormal situations.
• Control of compressor equipment switching on and operating duration.
• Maintaining pressure in the pneumatic system within the specified range.
• Supply of compressed air to onboard consumers according to their priority.

Use of system modules distributed throughout the train consist and united in a common network. Extensive interaction of brake control devices with the EMU control system. Exchange of operational and diagnostic data in real time.

Ensuring a high level of safety (not below SIL3) through function redundancy, self-diagnostics, and duplicated brake control via digital (electric) and analogue (pneumatic) channels.

Compressed air is supplied in priority order to consumers with the greatest impact on safety. Secondary consumers are supplied as air reservoirs charge and load on compressor units decreases.

Software and hardware redundancy of modules and communication circuits in case of failure. Extended service life of compressor equipment through reduction of cold starts, ensuring at least one compressor unit ready for operation at any time.

Use of standardised equipment in all train cars. Convenience and speed of replacement during maintenance and repair, as well as addition of new devices when expanding functionality.

Use of pressure and speed sensor readings separately for each car and wheelset to analyse changes in braking forces and system operation, and to decide on activation of anti-skid devices.

Use of algorithms that forecast compressed-air demand based on own sensor readings and data from the EMU control system. Bringing compressor units to readiness for start at the designated time.

Adaptation of braking forces along the train length for the most effective train braking.

Distribution of switching cycles among available compressor units depending on actual operating time and number of starts for uniform use of their resource.