Abstract: As the identification equations for robots’dynamic parameters become very complicated with the increase of joints，it is difficult to obtain accurate equations of dynamic parameters when a robot is of more than four joints．In order to solve this problem，a step-by-step identification method is proposed． In this method，less inertial parame-ters should be identified in each step，which results in simpler identification equation，more efficient calcu-lation and smaller accumulative error． Therefore，the parameter estimation can be achieved quite well for the robots with more than four joints． In order to validate the effectiveness of the proposed step-by-step identification method，a robot with six degrees of freedom is taken as an object to conduct the corresponding identification experiments．The results demonstrate that the proposed method is a simple but effective way to obtaining the key dynamic parame-ters of robots without changing their key dynamic characteristics．

Key words: industrial robot, dynamic parameter, step-by-step identification, identification algorithm, trajectory optimization