High mechanical advantage ratcheting apparatus

A controllable ratcheting apparatus operated near a mechanical singularity for obtaining large force over a specified distance, comprising:

• a plurality of modular joints;
• a plurality of links movably connected to said modular joints, wherein said links are connected to form at least one closed end chain;
• ratcheting means;
• and
• a control system to control movement of said modular joints and said links.

A method for controlling a ratcheting apparatus including a plurality of modular joints, a plurality of links movably connected to the modular joints, ratcheting means, and a control system to control movement of the modular joints and links, wherein the plurality of joints forms a closed chain, said method comprising:

• locking the plurality of joints in the closed chain;
• unlocking a selected first set of joints in the closed chain;
• moving said selected first set of unlocked joints away from a mechanical singularity;
• locking at least one of the joints in said first set of joints and unlocking other joints to form a selected second set of unlocked joints in the closed chain;
• moving said selected second set of unlocked joints away from a mechanical singularity;
• and
• repeating the sequence of locking at least one of the joints in a set of joints which has been moved, unlocking other joints to form another selected set of joints, and moving the selected set of joints away from a mechanical singularity, until a desired movement is completed.