Observer validation and model based control of a two mass oscillator with backlash

In many technical systems, like for example automotive powertrains, the torque generated by the actuator is transmitted through an elastic shaft with backlash, which results in a system where the controlled variable is not collocated with the actuator. A model based pole placement control approach can be used to achieve satisfying closed loop dynamics. However for this approach the system states have to be known, but for cost reasons not every variable can be measured. Therefore a powertrain of an electric car is modeled as a two mass oscillator with backlash and a nonlinear observer is designed to estimate the system states in this paper. The comparison of simulated and measured data is used to validate the performance of the observer depending on the number of measured variables.