Method for controlling the motion of a robot arm, computing device and robot

A method for calculating an arm angle range of a robot arm includes: determining a pose at an tail end position of the robot arm; judging whether an angle of an elbow joint is within a limit thereof when an arm angle is 180 degrees; if yes, constructing a first position matrix characterizing the elbow joint by using the pose and the arm angle; constructing a second position matrix of the elbow joint by using DH parameters of other joints of the robot arm; calculating, according to the first position matrix and the second position matrix, a first arm angle feasible region satisfying a limit of a position joint; judging whether the robot arm has a secondary position joint; and intersecting with the calculated first arm angle feasible region to obtain an arm angle range if no secondary position joint is present at the robot arm.