An experimental study on torque characteristics of magnetorheological brake with modified magnetic core shape

In this article, a new type of magnetorheological brake is designed and its torque characteristics are investigated experimentally. The proposed magnetorheological brake consists of an outer housing, a rotating drum, magnetorheological fluid, and a copper wire coiled magnetic core to generate a magnetic field. At first, the structural configurations of the magnetorheological brakes are presented with conventional and modified magnetic core shape. To achieve enhanced braking torque under limited small size, a modified magnetic core shape is adopted in the proposed magnetorheological brake. After manufacturing the magnetorheological brakes and measurement of braking torque, it is verified that the proposed magnetorheological brake with modified magnetic core shape has improved braking torque compared to conventional-type magnetorheological brake. For the actuator application, the dynamic characteristics, such as rising time, settling time, and falling time, of the proposed magnetorheological brake is also experimentally evaluated by observing the step response. In addition, the torque tracking control performance is also investigated by adopting fuzzy–proportional–integral–derivative control algorithm for desired input of sinusoidal and multi-magnitude step input. It is demonstrated that the proposed magnetorheological brake can be successfully used as an actuator with limited small size.