Force sensing for object grasp with fiber Bragg grating based wearable haptic device

Tactile sensation is one of the most important sensory inputs extensively used by the humans for their perception. It is an important parameter for diverse biomedical and industrial applications involving robotic system intervention. The present study proposes design and development of a real time dynamic haptic force monitoring system for human grasping of various objects employing Fiber Bragg Grating sensor. The dynamic force variation on the index finger during grasping of an object with minimum force application is determined by the Fiber Bragg Grating based Haptic Device (FBGHD). The FBGHD comprises of a wearable glove provided with a base plate fixed on the distal phalanx of the index finger and a tactile plate, where both the plates are held together by supporting cylindrical beams. When an object is grasped wearing the glove, the supporting beam experiences a compressive strain which is an indicator of the haptic grasp force. The induced strain is sensed and monitored by fiber Bragg grating sensor bonded over the surface of the beam. Two categories of experiments for estimating effective haptic grasp force are conducted on incremental weights and further on random objects with varying weights, dimensions and texture. FBGHD acts a sensing element for a robotic system for haptic sensing of force application on an object grasp, that can be extensively utilized during robotic based healthcare or industrial application.