Method and apparatus for a high-performance hoist

摘要

A mechanical apparatus and method for a high performance hoist for raising and lowering a load, and control apparatus and method for controlling the hoist such that its operation is responsive and intuitive for a human operator. The mechanical apparatus provides a reel for winding a cable, a ball-screw for translating the reel, and an encoder on the reel with which the height of the payload may be monitored. Also disclosed is an operator's handle comprising a movable sleeve with a damper as well as a spring to return it to its null position. The control apparatus and method provides for a handle-nulling mode in which the payload height is servo-controlled to follow the displacement of the operator's hand grasping the handle. The control apparatus further provides a float-mode in which the payload height is responsive to the operator's forces applied directly to the payload. Further, a payload mass estimation system is provided such that the mass of the payload can be determined without waiting for a period of time to allow the payload to settle. In addition, a mode-switching algorithm for transparent switching among different control modes is also disclosed.