Characterization and Testing Bench Design for Magnetorheological Dampers

摘要

Magnetorheological dampers and actuators are based on the physical principle of non-Newtonian fluids and its behavior when under the presence of a magnetic field. A good mathematical approximation of this phenomenon is the Bing-Ham Model with the inclusion of the Bouc-Wen hysteresis which evaluates the non-linearity of the power ratio vs. velocity damping model. This study presents a proposed test for the identification process also experimenting with various operating conditions in which this type of actuator can be used such as in vehicle suspension systems, vibration control or prosthetic devices. The study began exploring various models representing the dynamic characteristics of these actuators, so that, to determine the state variables to be monitored. From the models studied it was determined that the test bench must consider the position obtained through a LVDT sensor and the current drawn by an electric motor as inputs as well as the damping force according to the speed variations as output, this is measured by a load cell. Dimensioning according to the ranks of the selected actuator operation was performed (RD-8040-1 Lord), so, minimum and maximum strength and speed at which the system will be subjected were defined in order to assess the full dynamics of the system. Therefore, a hardware and software based architecture is proposed along with a graphical user interface that allows applications to be used for identification and control of this actuators.