Steer-by-wire challenges hydraulics

Advanced tactile-feedback devices give electric drives the control and feel of hydraulic steering. In an MR-TFD, the rotor turns freely in the housing if there is no magnetic field. When the coil energizes, the magnetic field instantaneously changes the magnetically responsive material. The resulting torque on the output shaft is proportional to the input current. OOEMs are replacing their traditional vehicle hydraulic systems with intelligent electrical systems that reduce complexity and improve performance. Compared with hydraulics, electromechanical drives are more efficient, quieter, and do away with environmental concerns about leaks. Nonhydraulic systems also permit more ergonomic designs and are simpler to install. Hydraulics has been around for years and OEMs are comfortable with it. But the potential advantages of electric systems, and the fact that their performance has dramatically improved in recent years, are pushing vehicle manufacturers to take a closer look at this alternative. One growing trend is the switch from standard hydraulic steering to all-electric or bywire steering systems. The systems rely on electrical technology but maintain the feel of traditional hydraulics, at least from a driver's perspective. This approach has several benefits. For one, it is less expensive to route wires than hydraulic hoses. Electric systems also tend to be more compact, lighter, and more efficient than their hydraulic counterparts. For instance, by-wire steering is a great advantage in "man-up" vehicles that hoist operators to high racks in warehouses because it eliminates complex mechanical steering linkages. And from an ergonomic standpoint, electrical steering takes less effort and