tailieunhanh - Inverse kinematics of a serial parallel robot used in hot forging process

This modification of the structure could make it a bit of challenge in the system modelling and controlling. This paper addresses the inverse kinematics analysis that is the central issue for developing autonomous control modes of the robot application. | Vietnam Journal of Mechanics, VAST, Vol. 38, No. 2 (2016), pp. 81 – 88 DOI: INVERSE KINEMATICS OF A SERIAL-PARALLEL ROBOT USED IN HOT FORGING PROCESS Chu Anh My Le Quy Don University, Hanoi, Vietnam E-mail: mychuanh@ Received March 12, 2015 Abstract. In hot extrusion forging process, the use of robot arm for transferring heavy billets can reduce downtime, improve productivity, reduce worker fatigue and optimize the use of energy and manpower. To increase the stiffness of the robot and force the endeffector move in directions parallel with the ground surface, two parallel links are added to a standard serial manipulator. This modification of the structure could make it a bit of challenge in the system modelling and controlling. This paper addresses the inverse kinematics analysis that is the central issue for developing autonomous control modes of the robot application. Keywords: Serial-paralell robot, inverse kinematics, hot extrusion forging. 1. INTRODUCTION Forging is a manufacturing process involving the shaping of metal using localized compressive forces. Forging is often classified according to the temperature at which it is performed: “cold”, “warm”, or “hot” forging. Consider a hot forging process layout in Fig. 1. Fig. 1. Layout of forging station Fig. 2. Forging process c 2016 Vietnam Academy of Science and Technology 82 Chu Anh My A steel billet weighted about 60 kg is heated up to 1100◦ C in the heating furnace, and it is then transferred to the forging machine. The forging machine is a hydraulic press system used for the extrusion process. After the billet located in a die fixed in the machine, it is pressed under the force F by the hydraulic press equipment, to produce the forging part (see Fig. 2). Since billets are hot and heavy, two workers are required to carry and transfer billets one by one for the process. This causes instability, worker fatigue and downtime in the manufacturing. To overcome these .