Robot assembly in manufacturing systems is still a work-intensive process. A main difficulty that arises when trying to automate an assembly task with a robot is the precision required to position and orient the parts. This difficulty arises in several sources of error, such as robot accuracy, the gripping and presentation precision of pieces, and part tolerance. High requirements for part insertion also present a greater possibility for jamming of parts and bottlenecking of the assembly line. Using a compliant device mounted between the end effector of the robot and the gripper mechanism may relieve this situation.
In order to achieve the reality of cheaper automation solutions by using robots in high precision insertion tasks, a passive compliant gripper device would need to be used. A passive design would supply the user with a “bolt-on” device that did not require any extra controllers or interfacing between the compliant wrist and the robot main controller, as is the case with an active or hybrid design. Using the wrist in operation, the number of damaged parts and the number of crashes by the robot would be reduced. Other compliant devices that are currently offered by commercial companies are compared with the proposed design and debated.
After a study of existing compliant devices, a novel approach is presented. Utilizing an earthquake protection device for buildings as an initial idea fountain, a new compliant wrist design is formulated. The Passive Compliant Wrist design, based on a building support system, is exhibited in detail. A comprehensive discussion of the wrist in operation is also presented. The final design has also been verified using the dynamic motion simulation program, Working Model, by Knowledge Revolution.