Hybrid Actuation With Unidirectional Clutches for Handheld Haptic Controllers

Realizing high performance force feedback through a handheld haptic interface is challenging due to the limitations on actuator selection imposed by form factor requirements including size, weight, and cost. Here, we introduce a hybrid actuation mechanism composed of a geared motor and two active unidirectional clutches to achieve an increased impedance range and improve performance. One clutch is used to selectively couple a free end-effector to the geared motor only during haptic rendering, eliminating the high inertia of the geared motor in free space. A second clutch is used to ground the end-effector directly to the device body, allowing the device to render large force without stalling the motor. This hybrid mechanism renders free space and solid objects effectively in a passive manner and extends the impedance rendering capability of a haptic interface driven by a small motor while keeping the device lightweight, energy-efficient, safe, and low-cost.