Method of optimization of the robot-manipulator position in the technological process of laser cutting

A promising direction for the production processes modernization which uses laser cutting of metal blanks is the creation of the robotic lines that perform cutting operations with high productivity and accuracy. Modern robotic manipulators with rotational axes allow to orientate the tool quite effectively when performing laser cutting operations, however, their widespread adoption isconstrained by the low efficiency of the known approaches to the layout of robotic lines. Such approaches are based on the use of standard design solutions with a further search for the robot links movements by trial and error, and often do not allow to ensure the required quality of the cutting tool path. In this paper, we propose a new technique for optimizing the robot-manipulator position relative to the cutting contour, which takes into account, compared with known approaches, constraints on  the  possibilities  of  the  cutting  tool  movements,  as  well  as kinematic  and  geometric  constraints  on  the movements of the robot itself. The proposed technique is based on a kinematic model of a robot manipulator and a cutting tool and allows finding the coordinates of the robot manipulator base position, at which it can move the cutting  tool  along  the  cutting  contour  with  a  minimum  range  of movements  in  the  joints.  The  search  of  the optimal  coordinates  of  the  robotic  manipulator  base  position  iscarried out in two stages. At the first stage, the area of admissible values of the coordinates of the base isdiscretized with a certain step and for each discrete value  it  is  a  trajectory  sought  on  which  the  range  of  movements in  the  joints  of  the  robot  is  minimized. This allows to take into account technological constraints on the orientation of the cutting tool relative to the cutting  contour,  as  well  as  kinematic  and  geometric  restrictions  on  the  movements  of  the  robot  manipulator. At the second stage a position of the base is selected which corresponds to the minimal volume of movement when  the  technological  tool  is  moving  along  the  cutting  contour.  The  effectiveness  of  the  proposed  method is demonstrated on model examples. The technique can be used inthe design of new layouts of robotic systems for laser cutting of metal blanks for mechanical engineering enterprises.

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