The locomotive type 714 was reconstructed at Vítkovice Doprava a.s. with a main goal of environmentally
friendly operation. This requirement may was fulfilled with the traction made of combustion engine paired
together with an electric generator, which is the most cost-effective solution. Pulling power then can
be also controlled easily. Original diesel engines were therefore replaced by internal combustion engines
with spark ignition using natural gas CNG for fueling. For this particular purpose the TEDOM CNG engines
of power 250kW were used and directly coupled with original electric generators. The advantage of this
solution is the maximum available torque (pulling power) from zero speed.
Engine control is performed via master control system sending the output power request to engine control
unit. The engine power itself is controlled by electronic throttle driven by CAN-bus.
Scope of our supply:
The vehicle is based on main platform of Mercedes-Benz Actros with the gritting bodywork attached to it.
The gritter is working in three basic modes of operation, i.e. salt pouring, inert material pouring or
salt brine pouring. As the amendment the fourth mode of operation was added to utilize the gritter for
a road repair after winter season. The gritting body is controlled by means of mobile control system thus
is possible to control the gritting body from the driver’s cabin or via remote control. To ensure the
proportional regulation of the pouring intensity the body control system is communicating with the engine
control unit/tachograph from which the vehicle speed and other parameters are being read.
Available are also operation statistics and expended material recording together with bodywork status
diagnostics and diagnostics of control unit communication. Gritter can be employed all year long – for
gritting at winter and for a road repair works during other seasons.
Our company developed a system for the TEDOM TD242 diesel engine control for use on railway vehicle, which
consists of the engine control unit and a power switching module. The engine paired together with Voith/ZF
automatic transmission creates the driveline of vehicle. Engine management is driven by CAN-bus consisting
of individual participants as the engine control unit, transmission control unit and vehicle management
Communication is based on protocol SAE J1939 incl. several proprietary modifications. The engine control
unit drives the engine actuators via a switching power module which is electrically isolated from the
power supply and from the vehicle bodywork.
This project was realized in cooperation with THT Polička where a fire truck bodywork was installed on
a MAN TGM 13.240 4x4 BL platform. On the bodywork there are placed the water of tank 3.2 cubic meters
volume, high pressure water pump system and intake valves to enable watering either directly from the
tank or from an external source of water. Inside the bodywork is also located other necessary equipment
such as electric generator, powder extinguisher, floating pump, etc. To lighten the place of fire-fighting
operations is possible to eject pneumatic lighting mast, which has a light output 4x500W.
From the perspective of body management and control is the vehicle equipped with five PLC’s and two HMI
displays. Thanks to this solution the body can be controlled using the 5,7”HMI located at high-pressure
pump at the rear of the body and also by smaller HMI display from the driver’s cabin while ensuring continuous
monitoring of the state of readiness to ride, i.e. the vehicle status after the intervention - whether
there are no tilted steps, open blinds, etc. The pump displacement is controlled by the means of engine
RPM in a proportional way. Therefore engine speed is controlled via CAN-bus utilizing the SAE J1939 protocol.
This type of vehicle is available in two versions - urban or suburban bus designed with environment in
mind. Since the gasoline prices are still rising, economic and also environment friendly operation can
be achieved by utilizing highly compressed natural gas as a fuel. The driveline system consists of combustion
engine TEDOM in conjunction with automatic transmission Voith or ZF. The engine is controlled by an electronic
throttle which communicates with the engine control unit via CAN-bus via SAE J1939 protocol.
There are also several vehicle management systems available like ECAS for vehicle tilt control and WABCO
braking system combining features of ABS and ASR, thus anti-lock and anti-slip protection. All these systems
are also members of a CAN-bus and if there is a requirement to reduce torque when shifting or detected
wheel slip during acceleration the engine ECU responds to them. The engine control also features advanced
diagnostics according to SAE J1939-73.