【作者】

Bert Ritscher，Martin Greve

【摘要】

论文已在中国上海举行的2013年CIMAC大会上发表。论文的版权归CIMAC所有。 CATERPILLAR has recently announced the development of the new M46 Dual Fuel engine.This high efficient engine is equipped with an integrated CATERPILLAR electronic control system including two ECM’s for the inline engine. They also include the control logic of the FCT flex cam actuator.The safety and protection system is a CATERPILLAR new development as well and connects to the Control System with a redundant Bus Interface, providing flexible PLC logic for Start Stop Control, Slow Turn, Purge and all other functions. Besides the known data interfaces to the engine control room and alarm system, all engine data is now visible within graphical on engine displays. The engine provides an output power of 900kW/cyl at a BMEP of 21.3 bar in Diesel as well as in Gas operation. To reach the high efficiency targets while maintaining sufficient safety margins at varying gas qualities, it was decided to equip this engine with cylinder pressure sensors in each cylinder and to integrate these informations into the engine control strategy. While other known cylinder pressure based control strategies focus on Pmax only, the new M46 DF engine uses further combustion characteristics like Start,Center- and Duration-of-Combustion for monitoring, balancing and NOx control. Time to market was and is still a critical factor to the success of this new project, so it was decided to build up a partnership with an experienced supplier in the technical field of cylinder pressure sensing and processing technology. Thecompany AVAT from the german city of Tuebingen has been selected to design and develop the CATERPILLAR In-Cylinder-Pressure-Module (ICPM). AVAT is a well known supplier to CATERPILLAR as they already deliver products and services for the GCM34 and other engines. Even more important than achieving maximum control performance was to design a system with highest engine availability. The new system architecture was developed such that the system complexity was minimized. Therefore the ICPM was designed as a smart sensing device leading to a clear separation of responsibilities: sensor power supply, sensor signal processing and monitoring as well as on-line calculation of combustion characteristics and knock levels are encapsulated in the ICPM, whereas mixture control, knock control interaction and balancing strategies are realized completely in the ECM. Consequently, error handling and alarm processing are also located here, giving CATERPILLAR the maximum flexibility in designing the engine behaviour. The key combustion parameters were defined by the CATERPILLAR control and performance team. The engine control system receives these values from a high speed digital bus interface using SAE J1939 CAN protocol. Appropriate extensions to the J1939 standard have been designed and submitted to the SAE committee. This clear interface provides good flexibility of all units and a clear hierarchy of the distributed system enabling CATERPILLAR to use the ICPM on different engine platforms. During common system FMEA sessions between CATERPILLAR and AVAT safety critical functions and performance optimization could be clearly separated, which, in turn, facilitates the marine classification process. The paper ends with a presentation of test bed results showing the benefits of the new control strategy.

【会议名称】

第27届CIMAC会议

【会议地点】

上海

【下载次数】

1

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