Automatic system copes with variable PCB production

The automatic assembly of photo products has been developed by Nikon Corp. over more than ten years. Automatic assembly methods are historically classified into three categories: dedicated machines, semi-flexible automatic assembly systems, and universal automatic assembly systems. This paper surveys these types of automatic assembly systems. First, automatic assembly systems for mechanical components of photo products are considered, and their background and design policies discussed. Next, the performances of these assembly systems and the results achieved in practise are described. Finally, the future trends of photo product automation are outlined.

Approximate analytical performance models for automatic assembly systems with statistical process control and automated inspection

The engine is one of the key core components in aircraft, in order to enhance automation and efficiency in the process of installation and disassembly for current small engine, using automatic control technology, a set of automatic disassembly and assembly system for aircraft engines is developed to replace the traditional mechanical installation vehicle. Corresponding for small engine to study the automatic disassembly system, the system uses laser sensors to locate the engine disassembly and assembly. Servo motors are used to drive the walking mechanism, lifting mechanism, and fine-tuning mechanism to realize multi-degree-of-freedom adjustment during engine disassembly and assembly. And the digital video is used to monitor the gap collision. Finally, the paper realizes the automatic high-precision disassembly and assembly of small engines. Through verification, the efficiency of the disassembly and assembly system has increased by more than 70%, the work efficiency has been greatly improved.

Screw assemblies of radar are characterized by numerous densely distributed small screws of various types, rendering their manual assembly difficult and inefficient. To improve the assembly quality and efficiency, an automatic assembly system was developed. First, the position and attitude relationships among the workpiece, camera, and base coordinate systems of the manipulator were obtained using three-point location and nine-point calibration methods. Second, a visual servoing strategy is designed for guiding the manipulator such that its position can be adjusted adaptively to achieve the high-precision positioning of threaded holes. Third, a method for evaluating assembly quality is developed. The templates of angle–torque curves of various screws were produced by fitting experimental data. Furthermore, the assembly quality was determined by calculating the similarity between the angle–torque curves and templates based on the Fréchet distance. Finally, the feasibility was verified using a flat plate component with five threaded holes.

This article shows the consequences of using parts with scrap in an automatic assembly system. The scrap is the percentage of parts that do not reach the required conformity and will cause either a defective assembly or a jam in the system. The two consequences considered here are extra cost and loss of productivity. To show this, we will focus on one part assembly operation anywhere in the process, which consists of feeding, assembling the part and inspecting the resulting sub-assembly.

Impact of quality improvement on optimal buffer designs and productivity in automatic assembly systems

Advantages of Sub-Batch Principle in Flexible Automatic Assembly as Used in the IVF-KTH Concept Mark II

Robotic assembly of smartphone back shells with eye-in-hand visual servoing

In several instances ofdiscrete event dynamic systems (DEDS), jobs sometimes require service from two or more resources at the same time. When queueing network models are used to study DEDS, this feature ofsimultaneous resource possession is often ignored because it is difficult for the models to handle. In some DEDS, this feature of a job demanding several resources simultaneously can have a significant effect on system performance, especially if there is a limited amount of one or more of these resources. For example, in an asynchronous automatic assembly system, an assembly at a workstation needs an operator when it experiences a jam (a random phenomenon) in order to clear the jam. Due to the presence of a limited (small) number of operators, an assembly may have to wait for an operator. This waiting orinterference time has a significant effect on the system production rate. This paper develops an analytical approximation method that can be used to determine the steady-state performance of automatic assembly systems for a given assignment of operators. The analytical method involves the simultaneous solution of two “coupled” queueing models; one of the models calculates the waiting time for an operator resource, while the other computes the waiting time for a workstation resource. The solution technique developed can be adapted to study instances of simultaneous resource possession in other DEDS, such as flexible manufacturing systems and computer/communication networks.

This paper describes a novel design and manufacturing method for next-generation probe cards. This method consists of the following essential concepts: (1) universal assembly by a single method; (2) precise tip motion-controllable probe structure; and (3) fully automatic probe assembly system. This technology realizes a fine-pitch and high-pin-count area-array probe card to test 3D ICs by through-silicon vias (TSVs) and a discontinuous fine-pitch array probe card for parallel testing of high-end ICs such as liquid crystal display (LCD) drivers, using common design tools and equipment. In this study, a new probe card was realized using the three concepts for fine-pitch area-array testing with a minimum pitch of 40 μm and more than 1,200 pins. Consequently, low probe contact force was achieved, which was less than 10 mN with large overdrive of 60 μm and a scrub value of less than 1 μm.

This study deals with reducing of transmissive vibration force by the interference method. The improved mechanism of the machine is constituted as two degrees of freedom vibration system. Assuming to eliminate a coupling spring, natural frequencies of two mass-spring systems are tuned to the same value each other. Vibrations of two bodies in the mechanical system are always held out of phase independently of exciting frequency. Then a fundamental resonance disappears and the secondary resonance becomes the only resonance, because the system is divided into a pair of mass-spring system by a node in the coupling spring to be regarded as a common fixed end. The new type vibratory feeder for automatic parts assembly system has developed as one of application of the vibration reduction method.

Development of a novel integrated automated assembly system for large volume components in outdoor environment

Processes with high energy assistance, such as ultrasonic vibration or local heating, and automatic assembly system in a progressive die were developed for micro metal forming in order to improve process accuracy of micro product due to some size effects in this study. Furthermore, application of textured diamond like carbon (DLC) coating on die surface was attempted to improve the tribological performance for dry micro forming operations.

Insect-computer hybrid robots offer strong potential for navigating complex terrains. This study identified the intersegmental membrane between the pronotum and mesothorax of the Madagascar hissing cockroach as an effective site for electrical stimulation to control direction and speed. A pair of bipolar electrodes was custom-designed, and an automatic assembly system was developed, integrating a robotic arm, vision-based site detection, and an insect fixation structure. The system achieved assembly in 68 s. Hybrid robots exhibited robust steering (over 70°) and deceleration (68.2% speed reduction) with performance comparable to manually assembled counterparts. Controlled navigation along an S-shaped path confirmed accurate directional control. Furthermore, a multi-agent system of four hybrid robots covered 80.25% of an obstructed terrain in 10 minutes and 31 seconds. This work demonstrates a scalable strategy for automating the fabrication of insect-computer hybrid robots, enabling efficient and reproducible assembly process while maintaining effective locomotion control.

This paper presents a new approach to detect and remove the shadows for workpiece localization, which is with an extensive application in automatic assembly system. However, the shadows of workpiece will badly affect this procedure as the contour of the shadow has the same shape with the workpiece itself in the image. The localization system treats the shadow as a part of the workpiece and make incorrect decision. So removing the shadow in the image before localization is meaningful. Our approach use CAD model to estimate the pose of workpiece, and the contour of object can be drawn in the image. Gray and texture features are used to detect and remove the shadow around the workpiece, and the workpiece is localized without the disturbance of the shadow in image. Experiments have been designed and performed. The experimental results demonstrate the effectiveness of the proposed method.