Automotive Production Line Research Articles

Real-time 3D shape inspection system of automotive parts based on structured light pattern

The non-contact 3D area sensor technology has achieved many successes in a variety of offline measurements. However, it has not been implemented for online measurement in the automotive production lines. The biggest challenge is the capability of simultaneously satisfying the efficiency, reliability, and accuracy requirements. For this purpose, a real-time 3D area sensor based on structured light pattern is proposed. To satisfy the requirement of online measurement, a one-shot pattern using monochromatic light is proposed. Compared with the previous patterns, this pattern is more robust because it can avoid the influence of the ambient light and the inspected part reflective property. Moreover, the requirement of the accuracy performance is achieved by the pattern primitive which is similar to the corner of the checkerboard since it can provide high accuracy performance even when the occlusion occurs; also, the pixel-to-pixel calibration strategy is utilized to increase the accuracy of the inspection system. Such a real-time shape measurement system has been successfully developed in our laboratory. Last, the evaluation experiments are conducted. The experiment results demonstrate the robustness and accuracy of the approach on automotive parts with different surface properties.

Improvement of earliness and lateness by postponement on an automotive production line

This article takes an interest in improving the performance of a subproblem of car sequencing: the resequencing problem. It extends a model of assembly line with the simulation of buffer stocks with drawers. Presequencing and resequencing are modeled with different types of stock management policy. Furthermore, postponement is introduced by two points of differentiation within the line. After choosing relevant variables and performance indicators a large-scale design of experiments finally enables to estimate average improvement brought by postponement to more than 39.7%, compared to the situation without postponement.

Predicting the performance of candidate human systems within specific work contexts

This paper describes concepts embedded into an ‘enhanced multi process modelling’ approach designed to capture and reuse coherent models of enterprise processes and human systems. Human systems are modelled in terms of the competencies and capacities they can bring as potential occupants of work roles. Multiple dependent enterprise processes (used by a specific ‘manufacturing enterprise’) are also modelled. The process modelling enables separable groupings of activities to be identified and designated as required work roles, to which competency and capacity requirements are associated. By coherently modelling role requirements and potential role occupants, and at needed abstraction levels, the enhanced multi-process modelling approach (i) supports human system selection (from among candidates), (ii) enables the development and testing of simulation models (that predict relative cost and lead-time performance of alternative role occupants) and (iii) enables the generation of workflow models (that support the runtime management and control of work through specified process and human resource system configurations). The current paper illustrates the use of the developed approach and observed benefits in respect to (i) and (ii). An example application of the approach is described that concerns the human resourcing of a machine design and build process currently used by a vendor of automotive production lines.

Infrared seed inspection system (IRSIS) on painted car shells

This paper describes a newly-developed automated thermal system for detection of seeds on newly painted car shells. The system’s novel approach is to use thermal emission; previously applied techniques relied on light reflection strategies. The system is described beginning with analytical modeling of the underlying detection theory to verification on a pilot run in an automotive production line. Parker’s flash procedure, using a thermal detector, was performed to extract the thermal properties of inspected panels. New computer logic developed in-house for processing the acquired thermograms is also presented.

Line balancing and simulation of an automated production transfer line

PurposeThis paper presents an investigation on the line balancing of an automated cylinder block production transfer line in order to reduce the total cycle time and increase machine utilization in an automotive plant. Results were verified by computer simulation, which showed increased throughput and higher machine utilization as a result of line balancing.Design/methodology/approachThree main operation lines of the transfer line were identified as critical and having the highest cycle time and were chosen for optimisation study. Strategies of re‐sequencing of existing operations and tools were used to reduce the cycle time of these critical operations and to balance the line. Results of a simulation study using Simul8 software are also presented to demonstrate the increase in machine utilisation and throughput as a result of line balancing.FindingsOwing to line balancing, the cycle time of cylinder block line was reduced from 293.9 to 200 s, an almost 32 per cent reduction. This also resulted in increased throughput and machine utilisation. Throughput was increased by 65 per cent. Machine utilization was found to increase at all stations, with the highest increase at one station was recorded from 48 to 95 per cent due to balancing.Originality/valueIntroduces a new application to line balancing of automotive cylinder block production line. Demonstrates that effective strategies of re‐sequencing and changing of tools can lead to more balanced production line with increased throughput and higher machining utilisation, resulting in higher productivity.

Automation of the car battery lid assembly operation

Automation of an assembly operation in an automotive lead/acid battery production plant is described in the paper. The operation—assembly of the polypropylene lids on the battery containers—is automated using robot technology. During the process of lid assembly, it is necessary for two plate stack electrodes to slide into two hollow lead terminals in the lid. In the part mating task the sticking is possible to occur bringing the assembly process into the halt. To design an automatic assembly system the lid assembly operation is considered as a problem of multiple peg-in-hole insertions. The paper investigates the basic principles of a multiple part mating task with special regard to the lid assembly. The theoretical and experimental findings are presented enabling improved understanding of the lid assembly process. On this basis, the robot workcell is built and assembly strategy proposed. Presented are the design of the workcell peripheral devices and incorporation of the workcell into the existing automotive battery production line.

Reduction of spatter in high-speed pulsed MAG welding

Summary Undercut and/or humping are generated when the arc length in high-speed pulsed MAG welding is too high, and spatter is generated if it is too low. Refinement of the droplets from the wire and simultaneous maintenance of one droplet transfer per pulse avoid short-circuiting in a short arc and enable spatter and highspeed/high-efficiency welding to be rendered compatible with each other. The requirements are to maintain a stable droplet shape during one droplet transfer per pulse, to maximise the welding speed limit without spatter generation, and to develop a technology for arc length shortening at the limit of short-circuiting by wire droplet refinement as objectives basically centred on pulsed MAG welding. This paper describes an investigation of the factors controlling droplet transfer through a division being made into the driving force imparted to the droplets and the deformability of the weld metal receiving this force as well as a method of droplet refinement based on resolution of these aspects. Through the simple rectangular wave pulse of a high peak current being set for a short time using an inverter-type pulsed power source at a constant wire diameter to increase the electromagnetic pinch force, one droplet transfer per pulse is possible on condition that the droplet volume is reduced by around 30% as compared with that obtained using a conventional power source with a chopping transistor on the secondary side. To increase the droplet deformability, the wire composition can be changed to achieve one droplet transfer per pulse on condition that the droplet volume is reduced by 20%. These droplets also show the same surface tension as conventional droplets as well as a lower viscosity coefficient. Through a combination of a pulsed current waveform and improved wire properties, the droplet volume can be reduced to around one half that of conventional droplets. The critical speed of spatter- and defect-free welding is then increased as an improvement immediately applicable on an actual automotive mass production line.

Military Products From Commercial Lines

"Military Products From Commercial Lines" is a pilot program within the Air Force Manufacturing Technology Directorate's Industrial Base Pilots Office. TRW's Avionics and Surveillance Group (ASG) is leading the program. This pilot program will demonstrate commercial-military integration by producing F-22 military avionics modules on an automotive electronics production line operated by TRW's Automotive Electronics Group (AEG). To accomplish this requires a redesign of the modules so that they are producible using commercial automotive electronics processes. Dual use manufacturing also dictates establishing compatible business practices, manufacturing infrastructures and process technologies. Business practices that must be changed involve accounting procedures, contracting requirements, audit requirements and quality control. Manufacturing infrastructure improvements include incorporation of advanced concurrent engineering tools and process control software to allow economic production of small lot sizes. Process technology changes involve designing for production lines that are highly automated and compatibility with commercial practices.< <ETX xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">&gt;</ETX>

Quality assurance and clinical indicators in emergency medicine

Quality assurance and clinical indicators in emergency medicine

Some Trends in Productivity and Quality of Life

In management of technology in the late 20th century period, many trends are identifiable. With the importance of technology in today's world, these industrial/technological/sociological trends present great challenges and opportunities to management. For example, a proper balance between productivity and quality of life is an elusive goal. The writer had a unique opportunity to study some of these trends and developments in the automotive production line setting in northern European countries: Sweden, Germany, England, and Norway. The following report is a summary of these studies. Clearly, traditional production line problems involving boredom and labor unrest can be amelorated by job enrichment and teamwork organization which modifies cycle times* from about one minute to as much as 30 to 50 minutes. These trends and their impact on engineering management are worthy of careful study.