Driverless Bus Guidance Computer System
- Three single-board computers, each with:
- ESMexpress® carrier with FPGA
- XM50 PowerPC® ESMexpress® module
- PowerPC® MPC8548 at 1.33 GHz
- 512 MB DDR2 RAM
- SATA Solid State Disk
- 2 certified CAN cores
- Rear I/O (CAN, Ethernet, UART)
- Rear I/O transition module with transceivers
- Customized conduction-cooled housing solution with wide-range PSU
- -40 to +70(+85°C), EN 50155 Class Tx
- Conformal coating
MEN has contributed to a successful initial project that involves driverless buses; the PowerPC®-based computers used in this project control the speed and direction of the bus, with the bus moving on an "invisible" lane.
The required safety level SIL-4 is achieved through a combination of redundancy, a fail-safe CAN communication infrastructure and a certified operating system/BSP. Every system consists of three single-board computers in a redundant 2-out-of-3 configuration, each installed in a different place in the bus to avoid a complete system failure in case of a vehicle collision.
Each of these computers obtains data from all sensors via two CAN bus connections. Every CPU board compares its results with those of the other CPU boards. If one of the three boards delivers a different result, it is switched off and the entire system goes into safe state, which means that the bus stops and opens its doors.
The electronics used are based on standard CompactPCI® in single Eurocard format and are connected to the housing via conductive cooling. To do this each board is embedded into its own aluminum cover. All plug-in boards designed for ventilated CompactPCI® systems can also be used in this completely EMC-sealed, conduction-cooled enclosure with an integrated wide-range PSU, 3-slot CompactPCI® backplane and IP65 protection class.
The systems are EN 50155 compliant in regards to temperature, humidity, shock and bump, and have no sharp corners and edges. The I/O connectors comply with MIL-C-38999.
Photo by Maurits Vink, nl.wikipedia.org