Simulation, performance, and experimental validation of a high-speed traversing/positioning mechanism using electrorheological clutches

A high speed traversing/positioning mechanism using two electro-rheological clutches is described. The traversing mechanism can be used to wind filaments onto bobbins. The traverse speed is 5 m/s, the required turn round period is 10 milli-seconds, the traverse length is 250 mm and the turn round position must be controllable and repeatable within +/- 1 mm. These combined criteria of high speed and controllability makes the use of electro-rheological fluids an attractive proposition. Simulations produced using a dynamic model are compared with experimental results and these validate the simulation techniques. The effect on the performance of various fundamental electro-rheological fluid characteristics, namely electro-rheological shear stress, electron-hydraulic time delays and zero volts viscosity are considered together with the design of the mechanism. This illustrates the need for optimization of such mechanisms to meet the varied and difficult design requirements found in high speed controllable devices. Some practical difficulties in achieving a reliable mechanism are also discussed.