Automatic Train Operation
Mass transit vehicles are more and more often equipped with driverless systems to increase traffic speed and frequency, lower energy consumption, or to allow stops at the station that are precise to the centimeter. Automatic Train Operation computers on board the train are typically based on modular systems because they control a multitude of functions (status data that is continuously sent to the control center, or capture of data from the wayside sensors) and communicate with wayside equipment. As ATO functions are always safety-critical, the same computer can be used to control other safety systems of the train.
In one driverless underground application, up to 500 mobile and stationary control and management systems are needed to monitor the train ona line. In this case, the control and monitoring system provides a response channel that allows the permanent transmission of status data of the vehicles back to the control center.
The redundant CompactPCI computer systems consist of five independent units forming two 1oo2 systems and one separate system for communication and data storage. All five units feature 3U COTS CompactPCI cards with Pentium processors. The serial interfaces and an additional watchdog are implemented as IP cores in the on-boardFPGA. A second card in the system comes with eight additional serial interfaces which are all realized in FPGA. A third card delivers the remaining I/Os required in the system, consisting of digital I/O channels, analog outputs, counter pulses, a radar sensor to pick up data from the route sensors and interrupt inputs. All these functions are also configured in the on-board FPGA. An optional fourth card provides the MVB fieldbus interface. The complete electronics are screened for an operation temperature of -40 to +85°C and conformally coated.
As part of an ETCS system, another application, also based on 3U CompactPCI, combines the COTS Intel Atom system slot single-board computer F11S with a PowerPC MPC8314 driven peripheral slot CPU card F218. The F218 features a boot time below two seconds and acts as a diagnosis buffer that communicates with thehost CPU via Ethernet. Other standard peripheral cards include GPS and GSM functionality. The fieldbus interface in this case is Profinet.
Yet another application with EN 50155 compliant components uses 6U VMEbus as the basic system in combination with ESM Computer-On-Modules with PowerPC CPUs to provide the computing performance. Application-specific functions are implemented by means of IP cores in the FPGA.
Standard Components Used in this Example
The F11S single-board computer is a versatile 3U Eurocard CompactPCI board, equipped with an Intel Atom Z510P, Z530P, Z510PT or Z520PT processor.
The F218 is a CompactPCI slave CPU card which can be used as an Ethernet diagnosis buffer.