Robot frogman, humanoid mechanical arm and driving mechanism for stepless bending and twisting

The invention relates to a robot frogman, a humanoid mechanical arm and a driving mechanism for stepless bending and twisting, and belongs to the technical field of robots. The driving mechanism for bending and twisting comprises a rigid rod body, a woven alloy net sleeve, a flexible filling sleeve, an outer connecting ring and a flexible wrapping sleeve, the woven alloy net sleeve is of a cylindrical net sleeve structure formed by weaving shape memory alloy wires; the two ends of the woven alloy net sleeve are fixedly connected to the outer connecting ring; on the woven alloy net sleeve, two crossed shape memory alloy wire sections are fixedly connected in an immovable manner through a node connecting piece at the intersection of the two crossed shape memory alloy wire sections; and an arm action driving unit provides a driving voltage with the same potential for a junction point of two crossed shape memory alloy wire sections arranged on the node connecting piece through a wire of which one end is connected