Flexible and Precision Assembly

Flexible Assembly Systems - Hardware Components and Features: Basic components of a FAS.- Classification of flexible assembly systems.- Examples of industrial installations.- Issues in Design, Planning and Scheduling of Flexible Assembly: FAS design issues.- Network design for material flow systems.- Design for assembly.- Assembly planning.- Planning and scheduling.- Loading and Routing Decisions in Flexible Assembly Systems: Description of a flexible assembly system.- Optimization of station workloads and product movements.- Design and balancing of flexible assembly lines.- Numerical examples.- Simultaneous loading and routing.- Sequential loading and routing.- Loading and Routing Decisions with Assembly Plan Selection: Simultaneous loading, routing and assembly plan selection in a general flexible assembly system.- Simultaneous loading, routing and assembly plan selection in a flexible assembly line.- Loading and Scheduling in Flexible Assembly Cells: Loading and scheduling in a robot assembly cell.- Loading and sequencing in printed circuit board assembly.- Production Scheduling in Flexible Assembly Lines: Flexible assembly line with limited intermediate buffers.- Flexible assembly line with no in-process buffers.- Global lower bounds for flexible flow lines with unlimited buffers.- Just-in-time scheduling of flexible assembly lines.- Multilevel scheduling of flexible assembly lines with limited intermediate buffers.- Machine and Vehicle Scheduling in Flexible Assembly Systems: Dispatching scheduling.- Machine and vehicle scheduling - a multi-level approach.- Machine and vehicle scheduling - a single-level approach.

Assembly 4.0: Wheel Hub Nut Assembly Using a Cobot

Components of the Design Process of Flexible and Reconfigurable Assembly Systems

During the early 1980s, the concept of a flexible assembly machine was first suggested by Hounsfield (1983). Following this, a variety of research projects have been conducted in an attempt to develop a flexible assembly system that is functional and economically viable. The most significant contribution has been made by the EURICA EU 321 - FAMOS - INFACT* project. However, despite the developments made during these projects, no industrial based system exists today. This paper presents a simulation model of a novel concept for a multi-station flexible automatic assembly machine, and examines the application of a rule based control strategy for the control of a materials handling system used in such a system. * http://www.3.eureka.be/home/

Flexible Assembly Systems through Workplace-Sharing and Time-Sharing Human-Machine Cooperation (PISA)

An integrated system of master and fine scheduling of a flexible manufacturing (FMS) and assembly system (FAS) is discussed in this presentation.

This paper presents the first phase results of a collaborative effort between university researchers and a flexible assembly systems integrator to implement a comprehensive modular approach to flexible assembly automation. This approach, named MARAS (Modular Automated Reconfigurable Assembly System), has been structured to support multiple levels of modularity in terms of both physical components and system control functions. The initial focus of the MARAS development has been on parts gauging and feeding operations for cylinder lock assembly. This phase is nearing completion and has resulted in the development of a highly configurable system for vision gauging functions on a wide range of small components (2 mm to 100 mm in size). The reconfigurable concepts implemented in this adaptive Vision Gauging Module (VGM) are now being extended to applicable aspects of the singulating, selecting, and orienting functions required for the flexible feeding of similar mechanical components and assemblies.

This paper describes a Flexible Assembly System for high volume consumer power tools. It examines the strategic process by which the system was developed including market issues and design for automation and identifies pitfalls for the unwary. The system is described before concluding that high volume flexible assembly automation is possible and brings advantages of cost, quality and additional range to the market place. The underlying theme, however, is that it is only possible to succeed in FAS if the automation is put into the considered context of the whole Manufacturing Business.

As manufacturing trends shift towards customized production, the demand for agile automation systems capable of efficient adaptation to rapidly changing task requirements is rising. This work presents a flexible robotic assembly system that combines CAD based component localization, compliance control, and a multi-modal gripper to enable robust and efficient programming of complex tasks. The process can be easily configured for novel assemblies through a dedicated Graphical User Interface (GUI), which facilitates component identification and task sequencing. Component poses are extracted from 3D CAD models in reference to the assembly origin, while the active compliance scheme compensates for minor positioning errors. The gripper incorporates a parallel jaw element, a rotating module, and an electromagnet to minimize retooling delays. The first iteration of the proposed system placed first in the manufacturing track of the Robotic Grasping and Manipulation Competition of the 2019 IEEE/RSJ International Conference on Intelligent Robots and Systems (IROS), experimentally validating its efficiency.

This study investigates error detection and recovery for flexible assembly systems. A method for error recovery based upon an expert system is presented.

Following the success of flexible manufacturing systems (FMSs), their counterpart, flexible assembly systems (FASs), have been developed to automate factories further. As in a FMS, the cellular approach is considered as the most feasible and flexible configuration for a FAS by researchers. Because of the differences between manufacturing and assembly operations, the logic of cell formation between a FMS a FAS is not the same. This paper discusses the similarities and differences between FMSs and FASs, and assembly cell design problems. Since the time for assembly operation is usually relatively short, the transfer time is thus very crucial for the performance of assembly systems. Therefore a good assembly cell should be constructed in a way that the flows of products within this cell are mostly in sequence. More in-sequence flows usually have the advantages of smaller flow distance, easier material-handling problems and more efficient production. In order to achieve these advantages, we propose a...

In this paper, a flexible robotic assembly system with decentralized architecture is presented. The system is designed to achieve high reconfigurability so that it can adapt to changes in manufacturing environment; a new robot can be easily installed to the system and execute assembly tasks immediately, together with other devices. For easier reconfiguration, a semi-automated calibration method for positions of newly installed robots is integrated into the system. Our implementation of the assembly system consists of conventional manipulators and a belt conveyor. In the experiment, a new mobile manipulator was installed successfully and performed an assembly operation jointly with other existing manipulators.

Optimal selection and control strategies for a flexible manufacturing and assembly system

Fixturing is an important requirement for many manufacturing and assembly operations. If flexible manufacturing and assembly system are to be truly flexible then the fixturing must also be flexible. A novel grasping strategy and gripper for fixturing in 3-D is presented for robotic assembly. The proposed fixture has three fingers, each equipped with a suction cup, to ease the grasping process and increase attaching flexibility. Using this method, the designed fixture is sufficiently general in order to fully grasp a variety of generic parts. To position suction cups, several linkage-based mechanisms are employed. Pneumatic cylinders and electrical motors are used as actuators to solve the space limitation and weight problem. Software has been developed to calculate the relative positions and angles in the mechanism as required for reconfiguration. A novel localization method is established to compensate for errors related to initial dislocation of the part due to low accuracy part bins from which parts are grasped. Several force and mechanism simulations are provided to verify the function and performance of the fixture.

An aggregate scheduling problem for a flexible manufacturing system which consists of a machining and an assembly subsystem is presented. The aggregate schedule developed is used as an input to a real-time scheduling problem discussed previously by the author (Proc. 2nd ORSA/TIMS Conf. on Flexible Manuf. Syst: Oper. Res. Methods and Appl., Elsevier NY, 1986, pp.521-32). Although features of the flexible manufacturing environment are not explicit at the aggregate scheduling level, they are incorporated at the real-time scheduling level. The single-product and N-product scheduling problems are considered. To solve the problems two optimal scheduling algorithms are developed. Each algorithm is illustrated with a numerical example. The results are also applicable to the single-batch and N-batch scheduling problems.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>