CAN Newsletter December 2006

11^th international CAN Conference (iCC)

More than 120 engineers from all over the world attended the 11^th international CAN Conference (iCC), which has been sponsored by Vector Scandinavia. About half of the participants came from Northern European countries. The majority of the 24 presentations were related to CANopen technology. All the presented papers are documented in the iCC proceedings available from CiA Headquarters. Prof. Dr. Gruhler, member of the iCC program committee, said after the conference: “The quality of the papers was in average very high, product placement was really an exception.”
One of the most interesting applications presented was the distributed control system for hybrid electrical vehicles developed by the CDAC (Centre for Development of Advanced Computing) of the Indian government. Prototypes of the CANopen-based system were implemented in three-wheelers. The modules are based on the digital signal processor from Texas Instruments or on the micro-controller from Microchip. Most of the devices implement the CiA 401 device profile for generic I/O modules.
The Koncar Institute located in Croatia presented another interesting application: The CANopen-based control system for the Zagreb tramcar. The system uses three CANopen networks connecting the VMEbus-based vehicle control system and the three traction control units, the two auxiliary power controllers and several other modules including brake and door controllers. The hardware is based on Infineon’s 8-bit micro-controller or on Texas Instruments’ digital signal processor.

CANopen shearer load controls

The shearer loaders by Eickhoff Bergbautechnik use modular CompactPCI hardware from Kontron and the CoDeSys SoftPLC together with CANopen and Profibus in a single-system solution. The bundle can also be purchased as a pre-configured, application-ready platform for any control application. In addition to the timesaving hardware/software integration, customers benefit from the ability to customize the system with in-house CPU cards and I/O assemblies.

Increasing: automation in mining

Shearer loaders have established a worldwide reputation in mining coal seams. Depending on their design, they cut coal from the longwall face laterally up to 1,1 m and at a height of up to 6 m in one pass. Depending on the worked thickness, the cutting shearers have a diameter of 1,4 m to 3,2 m and adjustable height. The loosened coal falls onto the chain conveyor below the shearer and is transported away for further processing; hydraulically controlled safety shields secure the structure of the longwall during mining. In general, only one worker is needed to control the heavy machines, which weigh up to 130 metric tons.
In 1950, the Eickhoff company built the first, hydraulically-operated, longwall shearer loader. Since then, the system structure of shearer loaders has developed enormously, and the integrated control intelligence has increased steadily. In 1976, the first longwall shearer loader was equipped with electrical winches and cutting engines on the supporting arms. Eickhoff built the first remote controlled shearer loaders in 1978, and the first high-voltage shearer loader in 1984. In 1990, the first remote micro-processors were brought on board and in 1992 the first sensor-controlled shearer loaders were tested with three-phase current winches to increase performance even further. Since 1997, winch revolutions have been controlled by frequency converters and, in 2001, the Eickhoff SL 500 achieved a cutting capacity of 2 x 825 kW, which is equivelant to the performance of around 16 mid-sized automobiles. With their increasing complexity and performance, the control requirements for these shearer loaders have also increased. Automatic operation, data transfer to control panels, and remote intelligence for adjusting the shearer loader to suit the geological conditions of the seam are vital features of today’s system technology. For example, different cutting processes, which are used according to the geological conditions and mining planning to optimize production, must be controlled. The cutting drives and feed force must also be aligned automatically in order to avoid overloads and keep the system in balance. For all of these functions, which offer the same kind of ease of operation as the latest automobile electronics, there must be a controller. Until now, this has been based on a Motorola 68000 processor. However, this technology is reaching its performance limits, so developers were looking for a new control platform that would ideally last for many years.