Two-degree-of-freedom rotational parallel mechanism with two continuous rotating axes

A two-degree-of-freedom rotational parallel mechanism with two continuous rotating axes comprises a fixed platform, a movable platform, and three branch chains which can connect the fixed platform with the movable platform, wherein the first branch chain and the second branch chain are both composed of upper connecting rods and lower connecting rods; the upper connecting rod and the lower connecting rod of the first branch chain are correspondingly connected to the movable platform and the fixed platform through a ball pair and a hook joint; the upper connecting rod and the lower connecting rod of the second branch chain are both connected to the movable platform and the fixed platform through a rotating pair; the upper connecting rods and the lower connecting rods of the two branch chains are connected through moving pairs; two ends of a connecting rod of a third branch chain are correspondingly connected to the movable platform and the fixed platform through the hook joint and the rotating pair; an axis of