Application potential of high performance steels for weight reduction and efficiency increase in commercial vehicles

The fast-growing economy and the gradually established highway system have boosted the road trans- portation for both passenger and cargo over the last decade in China. From 2000 to 2010 Chinese GDP increased by around 10.15% annually and the sales of medium and heavy trucks by around 18.87% （sales increased from 0.2 million in 2000 to 1.3 million in 2010） according to the National Bureau of Statistics of People＇s Republic of China. Today commercial vehicles consume almost the same amount of fuel as pas- senger cars in China although the number of commercial vehicles is only about one fourth of passenger cars. It is estimated that around 50% of imported fuel to China each year will be consumed by vehicle transportation. This si- tuation will worsen fuel shortage problems in the long run and at the same time it is partially responsible for the ever- worsening air pollution in China. Due to the widespread overloading in China, lightweight development in commer- cial vehicles has fallen far behind that of passenger cars with the consequences that Chinese commercial vehicles consume in average about 20% more fuel, especially the heavy trucks, compared to European models. Under these circumstances it is essential to reduce the vehicle fuel consumption and in- crease the transport efficiency. The key solution thereby is to implement lightweight design in commercial vehicles as it has been successfully practiced over the last decade in the passenger cars. This paper summarizes highlights given in presentations during the ＂International seminar on the ap- plication of high strength steels in light weight commercial vehicles＂ with the focus on the development and application of Nb alloyed high performance steels made for lightweight commercial vehicles.

Observer-based fault detection for switched systems with all unstable subsystems

This paper deals with the fault detection observer design problem for switched system with all modes unstable.First,the error system model is presented.With the consideration of the instability caused by the unobservable condition of(Ai,Ci),a switching signal is obtained via average dwell time method and discretised Lyapunov function.By means of linear matrix inequalities,sufficient conditions pledging exponential stability and H∞performance are proposed.Through transferring the observer design problem into H∞performance analysis,proper observer gain is obtained via solving these LMIs.In the end,the validity of the proposed Luenberger observer is verified by an example.