Experimental Characterisation of Dry and Lubricated Friction on a Newly Developed Rotational Tribometer for Macroscopic Measurements

A new rotational tribometer is developed which can be used for macroscopic friction measurement and identification. The functional requirements of the tribometer are: (i) accurate displacement and friction force measurement, (ii) normal loading and measurement possibility, both statically and dynamically, and (iii) the possibility of applying arbitrary displacement signals over a large range of magnitude and frequency. These functionalities are decoupled as much as possible based on the principles of precision engineering. Experiments are performed for friction identification, which can be used for control purposes. The tribometer allows experiments in a large range of displacements and velocities, thus allowing various friction characteristics, such as break-away force, pre-sliding hysteresis, friction lag in the sliding regime, stick-slip and limit-cycle oscillations, and the Stribeck behaviour to be measured for one and the same configuration, and under dry or lubricated friction conditions. Such experimental results can be used to validate physically motivated friction models, or to establish or validate empirically motivated friction models, such as used in control applications.