Finger device of composite underactuated double-joint robot with differential-motion bevel gear system

Abstract

The invention discloses a finger device of a composite underactuated double-joint robot with a differential-motion bevel gear system, belonging to the technical field of humanoid robot hands. The finger device comprises a base, a motor, a speed reducer, a base shaft, a near joint shaft, a middle finger section, a far joint shaft, a tail-end finger section, a double-linked bevel gear and a spring piece. In the device, a single motor, a differential-motion bevel gear transmission mechanism and the spring piece are adopted to comprehensively realize the effect of composite underactuated capture, namely the fingers capture an object in a coupling rotating mode firstly ad then capture the object in a self-adaption manner; the capture process is humanized, the action is nimble, the object can be captured stably, the objects with different size and shapes can be captured in an automatically adaptive manner; the finger device has low requirements to a control system and is controlled easily; furthermore, the finger device has a simple and compact structure, little energy loss, high transmission efficiency and low cost, can be controlled accurately, is convenient to assemble and maintain, has similar appearance as the hands of a human body and is suitable for the humanoid robot hands.

Description

technical field [0001] The invention belongs to the technical field of humanoid robot hands, in particular to a structural design of a differential bevel gear train composite underactuated double-joint robot finger device. Background technique [0002] The hand is a very important organ for humans. In the field of humanoid robots, it is of great significance to enhance the function of the robot hand. On the one hand, by increasing the number of joints and the number of drives, the movement of the manipulator can be made more diverse and precise, but at the same time, this will make the mechanism complex and cumbersome; The accuracy of the movement is negatively affected. At the same time, the robot hand is required to be compact and flexible with sufficient grasping force. There are still many technical problems in this field. [0003] An underactuated mechanism is one in which the number of actuators is less than the number of joint degrees of freedom. Many humanoid dex...

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Problems solved by technology

[0007] 2) The grasping method of the under-actuated hand is mainly the gripping method, and it is difficult to achieve a better grasping effect of the terminal pinch; when there is no object grasping, the fisting action similar to that of a human hand cannot be achieved; it is also difficult to achieve the terminal finger segment ( 7) Each joint is in a natural bending state when pinching an object

[0008] 3) When the under-actuated hand grasps an object, the first finger segment needs to exert sufficient force on the object to trigger the second joint to pull the spring to deform and bend, which will lead to an unstable grasping phenomenon in which the grasping force squeezes the object away. Even if the object is grasped, it may cause the first finger segment to grasp the object too much and damage the object

The disadvantage of coupled fingers is that there is no adaptability to different objects when grasping objects

[0015] The device can realize compound under-actuated grasping, but its disadvantages are: complex mechanism, difficult installation and maintenance; too many springs, using spring decoupling to adjust the contradiction between the coupling transmission mechanism and the self-adaptive transmission mechanism, often makes multiple springs The deformation of the part is large, resulting in excessive and unnecessary energy loss

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