Development of an underactuated robotic hand using differential gear mechanism

Underactuated robotic hands require a certain mechanism substituted for actuators. The role of this ingenious mechanism is distributing a system input to several system outputs. In other words, one input from an actuator is distributed to every joints of a finger by the mechanism with the consideration for the task and environment. A typical example is mechanical linkages with different link lengths. Besides, there are tendon drive, hydraulic device, and so on. In this paper, the differential driving module is introduced as an alternative to the absence of an actuator. In addition we also present the development of a self-adaptive hand for performing dexterous manipulation tasks with the differential driving module.