Case study 1 - Multiple traction control

Upgrade a 30 year old locomotive to run with a homogeneous triple heading

-Hardly any documentation/circuit diagrams available for the vehicles
-Very different versions of control technology over the decades
-The available control technology consists only of conventional electrical equipment
-Numerous new sensors and actuators needed for safe remote control of the vehicle
-New technology integrated must be “deactivatable” so that the existing control technology can be used as a fall-back
-New technology should conform to current standards

AAIT has developed a vehicle control system from the ground up for this purpose that includes a driver’s cab display.
All conversion measures (electronics, mechanics, pneumatics) were planned and executed by a partner workshop.
Construction monitoring and commissioning were carried out by AAIT.
The vehicle control system functions range from ancillary equipment control to traction control.
The solution developed takes the current safety requirements into consideration.

Case study 2 - ETCS on-board equipment

Upgrade a 50 year old locomotive with an ETCS system

- Hardly any documentation/circuit diagrams available for the vehicles
- Very different versions of equipment on the vehicles over the decades
- Vehicles rarely matched the little documentation available
- Interface for ETCS on-board equipment is firmly specified
- Locomotive has no programmable controller for rapid deployment of the necessary interface with the ETCS
- Electrical controllers, level fluctuations and potential shift if the existing control technology becomes moist
- Minimal adjustments to electrical equipment
- The new interface must conform up to SIL 4, which the existing technology does not
- Installation of additional sensors and actuators to meet the safety requirements
- Current requirements for EMC and fire protection features must be met
- New technology should conform to current standards
- The workshop’s planning, execution and quality assurance must meet TSI requirements

The project planning began with a feasibility study with subsequent planning of a certifiable solution.
A special ETCS interface, that is also usable on other vehicles, was developed for the communication between the ETCS on-board equipment and the vehicle.
All mechanical, electrical and pneumatic conversion measures were planned. The conversions were implemented in collaboration with a partner workshop.
The project was topped off with the planning and execution of the commissioning by means of vehicle and track tests, as well as preparation of the required proof for the safety authorities and the departments named.

Case study 3 - Replacement of old GTOs

Develop an actuation unit that makes IGBT usable in GTO power converters.

Because GTO switching is considerably slower than modern IGBT.
During direct exchange, switching edges occur that overload the existing machines. AAIT employs an intelligent and cost-effective solution that makes possible uninterrupted operation of the existing hardware with modern IGBT.

Case study 4 - Radio remote control

SIL 3 Monitoring Control Unit

When retrofitting existing locomotives, what is important is that only minimal changes are made to the vehicles. Anything that is still functional should be left untouched.

- No changes to the existing vehicle control system
- No software changes to existing control systems
- Minimal adjustments to the electrical technology
- New technology should comply with latest standards and SIRF

The benefits:
- No new assessment of existing software
- No extensive effects analyses for changes in existing software
- No SIL classifications or even new assessment of vehicle functions, which have been tried and tested in operation for years

In this regard, AAIT configured and developed a control system - SCU (Safety Control Unit), which monitors all safety related vehicle functions as an autonomous device in radio remote control mode and intervenes with safety measures, if necessary. This includes monitoring speed, traction and train movement and also the brake. In addition, the safety control unit serves as an electronic interface between the mechanical section of the remote radio control and the locomotive.
AAIT has set and implemented SIL 3 as the defined standard.