Engine Management System Strategies for Mitigating Dual Mass Flywheel Resonance in Gasoline Powertrains

In today's fast paced and competitive automotive market meeting the customers expectations is the key to any OEM. This has led to development of downsized high performance engines with refinement as an important deliverable. However developing such high output engines do come with challenges of refinement, especially higher torsional vibrations leading to transmission noise issues. Hence, it becomes important to isolate the transmission system from these high torsional vibration input. To address this, one of the most common method is to adopt Dual Mass flywheel (DMF) as this component dampens torsional vibrations and isolates the transmission unit from the same. While Dual Mass Flywheel assemblies do great job in protecting the transmission units by not allowing the oscillations to pass through them, they do have their own natural resonance frequency band close to the engine idle (low) engine speeds, which must be avoided for a continuous operation otherwise it may lead to Dual Mass Flywheel failures. Thus, there is a requirement for hardware design to keep such band away from the engine operating zone, however it is not feasible to completely avoid it. One of the effective way to eliminate the failures is quickly move out of such resonance speed band & not to continuously stay in critical zone. To overcome this issue, an innovative engine control strategies (EMS) were developed and implemented to protect DMF. These strategies not only ensure that the DMF remains away from the resonance band in various operation conditions, but also enable a robust refinement in the powertrain operations. This paper discusses the study of different strategies, its implementation & validation for DMF Safety and reliability in Turbocharged gasoline engine under different operating conditions.