In 2010 an older automatic crane unit at Constellium’s Burg extrusion plant became due for modernisation. Although the AMC (Automatic Manipulator Crane) had been installed by another manufacturer, owing to the many years of successful collaboration in the sector of internal logistics the company entrusted the work to H+H Herrmann + Hieber.
Rack transport and rack management take place at the Burg extrusion plant by means of an automatic rack manipulator (AMC / process crane) in combination with appropriate floor-level conveyor technology. In some areas the rack manipulator has to be refurbished both mechanically and in terms of its control systems to bring it up to the state of the art. As an additional benefit, the modernisation also resulted in a not inconsiderable performance boost of the AMC. Precisely in the field of automated internal logistics for the transport of long articles, recent years have seen dynamic developments.
In the initial situation the structure of the control system was as follows: carried along with it the automatic rack manipulator had a switchgear cabinet with the control technology components and the power electronics. Energy was supplied by a current rail. Data communication to the transport management system (TMS) and to the fixed controls took place by way of a data light barrier using the FMS protocol. The TMS manages the warehouse and co-ordinates the transport tasks of the AMC. The conveyor technology and admittance checks were implemented by a control system already upgraded to S7 level.
The energy supply via a current rail was retained. Also, the existing data communication to the management system (TMS) and the fixed controls via a data light barrier were initially not to be replaced, so that nothing had to be modified in the TMS and fixed controls. The essential renovations were:
- the existing, mobile control cabinets. These were replaced completely by new, prefabricated switch cabinets having new switching equipment, etc. The complete power electronics system (frequency converter) was supplied new according to requirements. The wiring, sensor systems and other instruments were retained;
- the existing S5 control system. This was replaced by a S7 control system (while maintaining FMS communication);
- The gantry undercarriage with four drive units (synchronisation-controlled). To improve their running properties the crane gantries were fitted with four CV motors. The synchronisation control is done by a tried and tested method already used many times;
- the carriage frame with a new frequency changer. The existing drives were retained, but operated by a Movidrive B frequency changer with a DCS safety card, for classification in category 3;
- the travel path measurement at the gantries and carriages. The new requirements demanded an absolute path coding system with reader hear and direct processing of output signals for position control over the full crane travel distance of around 200 metres. The newly designed system now also compensates a “shed” / crane track extension of up to around 60 mm;
- part of the safety concept. The new control configuration is prepared for (eventual, if only later) incorporation in an overall safety concept of category 3;
- the lifting gear with controlled drive. a new SEW drive was fitted. The drive is operated by way of a Movidrive B frequency changer with an absolute value emitter with SSI interfaces and DCS safety card, to upgrade it to category 3.
When the contract was awarded, the current situation was again determined in detail on site. The technical implementation and work sequences were summarised in a binding specification submitted to the customer for approval.
In the subsequent implementation phase the plant had to be closed down for 2 weeks, during 7 days of which parallel mechanical jobs were carried out. The remaining 7 days were required for function tests and commissioning tasks; during that period no further work on the crane was possible. Various preliminary jobs (assembly of the travel path measurement systems, interface tests, etc.) were completed in advance.