Robotic Handling of Jet Engine Turbine Blade Using Collaborative Robot

The work discussed in this paper is a part of the project to build an automated robotic cell for removing two tabs from a Jet Engine Turbine Blade using a 3-axis CNC milling machine and for laser marking several lines of part information onto the blade body. The two tabs are extensions of the Turbine Blade, in which the necessary part information is ingrained. The part information is used as the identification of the Turbine Blade throughout its entire manufacturing process. The two tabs also serve as anchors during the milling of the body of the Turbine Blade in a 5-axis CNC machine. Once the milling of the blade body is done, the two tabs will be removed from the blade body. Removing tabs is currently being done in the same 5-axis CNC milling machine. It is expensive and wastes 5-axis machine time. Therefore, using a 3-axis CNC milling machine to remove tabs is proposed with a robot to tend machines to be cost-effective. Due to the complexity of the Turbine Blade having 3-D wavy geometry, it adds challenges in undertaking any operations on the blade with automation. This paper focuses on the development of an efficient method to tackle the challenges during part handling of a Turbine Blade in the proposed robotic automation cell. Some of the challenges include the selection of robot, the design of the cell layout, the selection of right gripper, design of the gripper fingers, determination of the gripping point and gripping force, and performing the motion planning to take the blade from infeed bin into the CNC machine, and out of CNC machine to an outbound conveyor. The motion planning involves many aspects, including collision avoidance, high position repeatability and accuracy, and minimization of cycle time. To achieve the minimum cycle time, an optimum robotic path and algorithm are developed and tested. The optimum robot motion parameters are calculated and tested. The effect of using different robot motion parameters on the repeatability and the cycle time is simulated and evaluated. The effect of using different optimum robotic paths is also evaluated for position accuracy and efficiency.

This paper is divided into four sections. The first section will introduce the background information about this automation project and the overall objectives of the project. The second section will discuss various decisions made in handling the blade by using a robot. Section three will discuss the challenges during motion planning and the experiments carried out to address those challenges. Sections four will summarize the experiment results and conclude from the experiments.

As automation is becoming relevant in many industries including the Aerospace, the method discussed in this paper can be used as a general guideline for carrying out material handling tasks with a thin part of wavy geometry by using a collaborative robot.