Operation of the Collaborative Composite Manufacturing (CCM) System

Summary

A collaborative composite manufacturing system is developed for robotic lay-up of composite laminates using the prepreg tape. The proposed system allows the production of composite laminates with high levels of geometrical complexity. The issues in the path planning, coordination of the robots and control are addressed in the proposed method.

Abstract

The automated tape placement and the automated fiber placement (AFP) machines provide a safer working environment and reduce the labor intensity of workers than the traditional manual fiber placement does. Thus, the production accuracy, repeatability and efficiency of composite manufacturing are significantly improved. However, the current AFP systems can only produce the composite components with large open surface or simple revolution parts, which cannot meet the growing interest in small complex or closed structures from industry.

In this research, by employing a 1-degree of freedom (DoF) rotational stage, a 6-RSS parallel robot, and a 6-DoF serial robot, the dexterity of the AFP system can be significantly improved for manufacturing complex composite parts. The rotational stage mounted on the parallel robot is utilized to hold the mandrel and the serial robot carries the placement head to mimic two human hands that have enough dexterity to lay the fiber to the mandrel with complex contour.

Although the CCM system increases the flexibility of composite manufacturing, it is quite time-consuming or even impossible to generate the feasible off-line path, which ensures uniform lay-up of subsequent fibers considering the constraints like singularities, collisions between the fiber placement head and mandrel, smooth fiber direction change and keeping the fiber placement head along the norm of the part's surface, etc. Moreover, due to the existing positioning error of the robots, the on-line path correction is needed. Therefore, the on-line pose correction algorithm is proposed to correct the paths of both parallel and serial robots, and to keep the relative path between the two robots unchanged through the visual feedback when the constraint or singularity problems in the off-line path planning occur. The experimental results demonstrate the designed CCM system can fulfill the movement needed for manufacturing a composite structure with Y-shape.

Introduction

Recently, the increasing need for high performance composite structures in various industries has greatly driven the development of the composite manufacturing technologies^1,2. The traditional manual production cannot meet the high efficiency, accuracy and quality requirement of emerging industry. This aspect has encouraged the development of new production technologies such as AFP systems. The AFP technology automates the production of composite material structures using prepregs, which are present in the form of strips composed of impregnated fiber tapes (glass, carbon, etc.) of semi-polymerized resin. In th....

Protocol

1. Frame Definitions of the CCM system

NOTE: The optical CMM is a dual camera sensor, which can track the object with a rigid set of reflectors as the targets in real time. The placement principle of these targets is that the targets are stuck at the asymmetric locations with certain distance among them. The targets need to be fixed on the robots or the placement head and remain in the field of view (FOV) of the optical CMM. At least four targets should be observed for each defined frame by the optical CMM all the time. The base frame of the parallel robot, the end-effector frame of the parallel robot, and the tool frame of the serial robot a....

Results

The experiment aims at demonstrating the process of realizing the motion of laying up the fiber on the Y-shape mandrel of the proposed CCM system. The process is carried out in three steps: path generation; trajectory decomposition; and singularity and constraint avoidance.

Path generation
Normally, the standard orientation is used in industry to define the different plies of the laminate. In this paper, t.......

Discussion

The experimental results show the manufacturing process of 90° ply placement angles of the designed CCM system. The methodologies proposed in this paper can be used to lay up the fiber with 0° and 45° ply placement angles on the mandrel with Y-Shape and other shapes. While the built-in controller of the serial robot is able to provide the singularity avoidance feature¹⁷, only linear movement of the end-effector is supported. When the end-effector executes the task of the circle move.......

Materials

Name	Company	Catalog Number	Comments
AeroBasic	Aerotech		Motion control software
Collaborative Composite Manufacturing (CCM) System	Concordia University		A CCM system is proposed to manufacture more complex composite components which pose high demand for trajectory planning than those by the current AFP system. The system consists of a 6 degree-of-freedom (DOF) serial robot holding the fiber placement head, a 6-DOF revolute-spherical-spherical (RSS) parallel robot on which a 1-DOF mandrel holder is installed and an eye-to-hand optical CMM sensor, i.e. C-track, to detect the poses of both end-effectors of parallel robot and serial robot.
C-track	Creaform Inc.		An eye-to-hand optical CMM sensor
Fanuc M-20iA	Fanuc Inc.		Serial robot
Matlab	MathWorks		A multi-paradigm numerical computing software
Quanser	Quanser Inc.		Providing the engineering lab equipments for teaching and research.
VB	Microsoft		Visual Basic
Vxelements	Creaform Inc.		Software for C-track