Conclusion
The calculated eight degrees of freedom can be verified in two ways.
The first approach to checking is counting the number of degrees of freedom parts of the mechanism
introduce. They are listed in order of ascending height on Figure 9:
• Joint 1 allows rotation about a vertical axis of member 2 relative to 1. (+1 DoF)
• Joints 5 and 6 permit vertical and horizontal extension and movement. (+2 DoFs)
• Joints 10 and 14 allow a secondary horizontal extension and movement. (+2 DoFs)
• Joints 20 to 25 allow rotation of the entire mechanism from link 16 onwards. (+1 DoF)
• Joints 24 and 25 allow a correcting tilt to the basket. (+1 DoF)
• Joint 26 permits a vertical axis rotation of member 21 (the basket). (+1 DoF)
The second method of checking this is that 8 inputs can be seen, and this must be equal to the mobility of
a mechanism. These inputs are:
• Joint 1 rotation.
• Joint 3 hydraulic.
• Joint 6 extension/retraction.
• Joint 12 hydraulic.
• Joint 14 extension/retraction.
• Joint 16 hydraulic.
• Joint 22 hydraulic.
• Joint 26 rotation....