According to one embodiment, a trim actuator for a pilot input device includes a driven member and a driving member configured to receive mechanical energy from a power source. A magnetorheological (MR) fluid is disposed between the driving member and the driven member and configured to transmit a variable amount of mechanical energy from the driving member to the driven member such that the driven member moves in a first direction. An output member configured to be coupled between the driven member and the pilot input device. A spring is in mechanical communication with the output member and configured to apply a force in a second direction opposite of the first direction. A magnetic circuit is configured to control movement of the pilot input device by varying the strength of a magnetic field delivered towards the first MR fluid.

Systems and methods relating to a clutch system for use in controllably transmitting torque from an input shaft to an output shaft. The clutch system has a torque transmission fluid that has a viscosity that changes based on the strength of an electromagnetic field passing through the fluid. A number of sensors are placed at different radial locations on the torque transmission disks to detect the strength of the electromagnetic field. Based on the strength of the electromagnetic field, the amount of torque being transmitted from the input shaft to the output shaft can be adjusted. Also disclosed is a distributed actuation architecture that uses this clutch system. The distributed actuation architecture allows for the use of a single drive motor in conjunction with multiple instances of the clutch system to actuate a mechanical linkage, such as a robotic arm.

A percussion mechanism includes a first shaft and a second shaft. One or more vanes are fastened to the first shaft. The vanes are arranged so as to be rotatable in a chamber of the second shaft. The chamber is filled with a magnetorheological fluid. A magnetic field source on the second shaft generates a magnetic field that is spatially modulated in the circumferential direction inside the chamber.

In some embodiments, a redundant control system includes first and second control systems, having first and second clutches, and a shared clutch system. The shared clutch system may include a shared shaft configured to receive mechanical energy from a shared power source, a first shared clutch corresponding to the first clutch and configured to receive mechanical energy from the shared shaft, and a second shared clutch corresponding to the second clutch and configured to receive mechanical energy from the shared shaft. A first linkage provides mechanical communication between an output of the first clutch, an output of the first shared clutch, and a first output device in mechanical communication with the rotor system. A second linkage provides mechanical communication between an output of the second clutch, an output of the second shared clutch, and a second output device in mechanical communication with the rotor system.

In some embodiments, an actuation system includes a plurality of threaded member portions, a plurality of roller nuts, a driving member configured to receive mechanical energy from a power source, a plurality of driven members, and a magnetorheological (MR) fluid disposed between the plurality of driven members and at least one braking surface. An output member may be coupled between the rotor system and either the plurality of threaded member portions or the plurality of roller nuts and configured to translate linearly in response to the threaded member portions advancing or receding within the roller nuts.

Clutch assemblies and associated methods are disclosed herein. In an example, a clutch assembly comprise a first terminal, a second terminal, a clutch body enclosing a torque transfer fluid, and one or more electropermanent magnets (EPMs), each configured to generate a respective EPM magnetic field. The clutch assembly is configured to transmit a torque between the first terminal and the second terminal with a torque capacity that is at least partially based on the EPM magnetic fields. In an example, a method of operating a clutch assembly comprises transitioning each of one or more EPMs to a fully depolarized state, a fully polarized state, or an intermediate polarization state. In an example, a method of operating a clutch assembly comprises controlling each of one or more EPMs of the clutch assembly to vary a total EPM magnetic flux generated by the one or more EPMs.

A system comprises one or more wearable devices including a first body interface adapted to be secured to a first bodily part. A second body interface is adapted to be secured to a second bodily part separated from the first bodily part by a physiological joint. One or more joints provide one or more degrees of freedom between the first body interface and the second body interface. A magnetorheological (MR) fluid actuator unit comprises one or more power sources. An MR fluid clutch apparatus receiving torque from the at least one power source, the at least one MR fluid clutch apparatus operable to generate a variable amount of torque transmission when subjected to a magnetic field. A transmission couples the MR fluid actuator unit to the wearable device for converting torque from the MR fluid actuator unit to relative movement of the body interfaces with respect to one another.