Automatic Assembly Technology of Dense Small Screws for Flat Panel Parts

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.

Automatic assembly equipment is the key to improving the efficiency and quality of workpiece assembly. The precision of assembly directly influences the overall quality of the assembled product. To optimise the position control accuracy in the automatic assembly equipment, a variable universe fuzzy proportional integral (VUFPI) controller optimised by the sparrow search algorithm (SSA) is developed in this paper. The developed controller adopts the SSA to adjust in real time the universe of the fuzzy controller according to the deviation of the servo system. The servo system model is established to evaluate the performance of the proposed SSA-VUFPI controller; furthermore, the SSA-VUFPI controller is implemented in the automatic assembly equipment for experimental evaluation. The analysis results demonstrate that the proposed SSA-VUFPI controller is capable of improving the anti-interference ability and position accuracy of the servo system compared to traditional PI, VUFPI, and currently used back propagation neural network proportional-integral-derivative (BP-PID), fractional-order PID (FOPID), and SSA-PID controllers. Moreover, it effectively improves the position accuracy of the workpiece and ultimately improves the quality of the assembly.

The visual servoing strategy of a continuum robot has wide-ranging applications and significant engineering value. However, limited by the accuracy of its motion control, research on visual servoing of continuum robots is currently limited to close-range conditions (distance < 1m). Therefore, a novel visual servoing strategy for continuum robots is proposed in this paper that can track external targets in real-time and across distance from centimeters to tens of meters. Firstly, a continuous mapping relationship was proposed by integrating the visual coordinate transformation process with the mechanical model of the continuum robot, establishing a mapping relationship between pixel error and drive values. Secondly, a closed-loop control system for trajectory tracking of moving targets is designed by combining the continuous mapping relationship. Finally, trajectory tracking experiments are conducted on a moving target (i.e., human-shaped target) at different distance scales. Compared with the eye-in-hand strategy at different distances (0.2m, 2m and 3m), the experimental results amply demonstrate the tracking accuracy and stability of the proposed visual servoing strategy. Furthermore, under the experimental condition of long distance (20.5m), the proposed visual servoing strategy can still achieve accurate tracking of the moving target, with an average tracking error of 27.97 pixels (about 2.31cm).

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

The helicopter fuselage has the characteristics of compact structure space, complex coordination relationship and weak rigidity, etc. It is difficult to control the accuracy of the desired shape. According to the high precision and quality requirement of final assembly for helicopter fuselage, the application status of automatic assembly technology in aviation manufacturing was analyzed. Then the difficulties of automatic assembly technology for fuselage final assembly were also discussed. In this paper, an automatic assembly system for the final assembly of helicopter fuselage was designed, and relevant key technologies of the assembly system mentioned above were proposed. The designed system have the functions of automatic positioning, clamping, measuring, drilling, feeding and blind fastener riveting for fuselage components, which can improve the assembly quality and efficiency of helicopter fuselage during the final assembly process.

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

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.

Since quadrotors are becoming more popular, several techniques appeared to control robustly the Unmanned Aerial Vehicle. This article proposes an intelligent image-based visual servoing (IBVS) control method for an unmanned aerial vehicle (UAV). This work consists of computing the proportional controller gain by smoothing the error between the desired and actual feature vectors values, as opposed to the classical visual servoing (VS) scheme. The weak handling of this gain, affect the maintaining of tracked features in the area of view. Unlike the classical VS scheme that requires a known value of gain, selected in a heuristic way, which lead the controller to fall in the velocity convergence problem. We adjust an adaptive gain value by the use of a fuzzy logic controller. The proposed controller exploits the error between feature vectors and its derivative as inputs. Furthermore, we design an intelligent based-fuzzy logic method for gain tuning of PD controllers applied for handling the heading and position of the quadrotor. The proposed controllers are applied to the inner and outer loop, offer several advantages in dealing the uncertainty occurred within trajectory tracking control. Various simulations are developed in MATLAB, shows the outperformance of the proposed method against the classical one.

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

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.

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.

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

Within the next year Plessey plans to install a CAD‐linked automatic PCB assembly system for batch quantities of one

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