|Budget Amount *help
¥3,600,000 (Direct Cost : ¥3,600,000)
Fiscal Year 1995 : ¥100,000 (Direct Cost : ¥100,000)
Fiscal Year 1994 : ¥1,300,000 (Direct Cost : ¥1,300,000)
Fiscal Year 1993 : ¥2,200,000 (Direct Cost : ¥2,200,000)
Using the theory of Degrees-of-Freedom, we have developed a constant velocity joint mechanism which has triple spherical linkages and applied to the wrist-joint of manipulators. This wrist-joint mechanism's features are as follows : Revolute type lower pairs only ; Singularity-free motion ; Over 180 degrees pitch and yaw angles ; 360 degrees continuous roll motion ; Internal cable routing passage ; High precision ; High rigidity ; Remotely driveable ; and Back-driveable. In this project, the method of statics analysis was developed. Because the statics analysis is a statically indeterminate problem. So, we introduced equations of consistent deformation on the intermediate links to calculate the joint reactions. In the method of designing, at the first step using the results of the joint reactions, we design the initial shape of link elements, and we examine the strength of the link elements by the CAE software, COSMOS/M.Based on the results of FEM.analysis, we re-design the more appropriate shape of link elements. At the second step, we calculate the compliance of the intermediate link, and re-calculate the join treactions. Finally, we examine the strength of the link elements again.
We also discussed the drive forces for the third model of the joint mechanism. The joint mechanism is 2 D.O.F.mechanism. So, it can be driven by two actuators. But we added third actuator to it. Using this redundant actuator, the drive forces are reduced to 30%. Consequently, we can use lighter and smaller actuators and link elements. In addition, we also calculated the motion errors of the joint mechanism with its kinematics constant errors to determinate the accuracy for manufacturing it.
The second model of the joint mechanism was mounted on the end of the industrial arm robot. We constructed an interface unit to synchronize the mounted joint-mechanism action with the robot action, and built up a robot control system included the proposed joint mechanism.