Positioning method, control device and system of mechanical arm camera obscura

The invention discloses a positioning method of a mechanical arm camera obscura and a control device and system. The positioning method comprises the steps that S1, position information of the free end of an arm 15 at the current moment is obtained; s2, calculating the position information of the free end of the arm 15 at the next moment; s3, determining a current one-arm triangle; s4, determining a target one-arm triangle; s5, determining a stepping offset according to the current triangle and the target triangle; and S6, according to the rotation angle alpha of the arm l2, the rotation angle beta of the arm l3 and the rotation angle rho of the arm l5, the arm l2, the arm l3 and the arm l5 of the six-axis mechanical arm are controlled to move to the target point in a stepping mode. According to the invention, the process of machine visual identification is omitted, the relative movement between the two adjacent arm levers at the joint of the six-axis mechanical arm is controlled in real time, the movement of