The Design And Simulation Analysis Of Energy Regenerative Suspension System On HEV

A conventional vehicle suspension system contains passive elements, namely a viscous damper and a spring. The damper converts vibration energy into heat energy due to the viscous friction of fluid in the device, and is finally dissipated to the external environment. Other than damper configuration, the amount of the energy dissipated largely depends on the road roughness, the vehicle velocity and the vehicle mass. Under common operating conditions, this energy may be considered insignificant. On the other hand, over rough urban roads, the energy may be higher and thus present a potential to tap the energy. For this, an energy regenerative device may be adapted to replace existing damper in the vehicle suspension system. With an appropriate controller, the device may be alternated between damping and generating device to provide damping as well as extracting energy. The energy even small may help in improving the efficiency of the hybrid vehicle systems. With such device, it is also possible to vary the damping in a nonlinear and adaptive manner to accommodate the conflicting requirement between high speed operation and control of resonance.The energy consumption of the traditional vehicle suspension can be analyzed by simulation, then get the damper energy consumption accounted for engine output energy by percentage in a variety of different speed and traffic, finally influencing factors were analyzed.(More dumpy the road is, the greater proportion of damper energy consumption. Higher speed the vehicle is at, the greater damper energy consumption. More stable speed, the greater proportion of damper energy consumption.) We can get the preliminary determination of the potential of the energy regenerative suspension. Under the present conditions, the energy wasted by the damper have the value to be recovered.Traditional damper has been replaced by the energy regenerative device in the energy regenerative suspension, and then the energy used to be wasted can be recovered. More energy traditional damper wasted, more energy could be recovered. This part of energy is quite meaningful for the hybrid vehicle, which energy consumption is rather low and has strict requirements on efficiency. So such kind of suspension is useful to hybrid vehicle, which can use the energy recovered directly, thus battery weight and oil consumption can be reduced.A model of energy regenerative suspension system has been designed according to the existing simulation data. The vertical vibration of the vehicle body is turned to the rotation of the motor rotor by gear rack agencies. The kinetic energy is turned into power by the generator, and then transformed to the capacitance. Through matching parameters, meet the basic working conditions, that the output voltage of generator is always higher than the capacitance. When the power collected by the capacitance is large enough, the energy is transformed to the power line through DC/DC device.The characteristics of the energy regenerative device have been analysed. the energy-saving features and frequency characteristics of the vehicle model, which loaded the energy regenerative suspension, has been studied. Karnopp control algorithm was applied in the suspension model, and studied by simulation analysis. Finally we got the following conclusion:(1)Although the damping characteristics of the energy regenerative suspension are not exactly the same as the traditional damping, they can meet the actual needs basically.(2)Energy regenerative suspension can be used as a traditional suspension, at the same time can recover some of the vibration energy. While such kind of suspension still has some problems need to be deal with, such as the efficiency and the adjustable scope of the generator.(3)Karnopp control algorithm can increase the energy saving effect, besides it can improve vehicle ride to a certain extent. But by the energy regenerative device limitations, Karnopp control algorithm performances can't be fully played. Thus there are lot of works need to do with the optimization of the actuator.