Fu Zhuang

Solar cell crack inspection by image processing

Spacecraft operate in a hostile environment, far from the Earth, so it is necessary for solar cells with anti-radiation properties to have a bonding process carried out on them. After bonding, an essential process for the solar cell assembly is to inspect for cracks on the edges or inside the solar cell. To avoid utilizing unqualified products and to improve the reliability of products, this paper presents a method to detect the cracks of solar cell by image processing. This method utilizes the gray transform, image adjustment, Gauss-Laplacian transform, contour detection, crack recognition, and so on. The validity of this method has been verified by experiment.

Research of the Localization of Restaurant Service Robot

This paper designs a restaurant service robot which could be applicable to providing basic service, such as ordering, fetching and sending food, settlement and so on, for the customers in the robot restaurant. In this study, both three landmarks positioning and landmark-based localization algorithms are proposed to localize the mobile robot with rough precision in the restaurant. And Optical Character Recognition (OCR) technology is used to distinguish the unique table number of different landmarks. When the high localization precision must be granted around the pantry table, the RFID-based localization algorithm is proposed to localize the mobile robot. Various experiments show that the proposed algorithms could estimate the robot pose reasonably well and could accurately evaluate the localization performance. Finally, the proposed service robot could realize real-time self-localization in the restaurant.

Fluid Model of Sliding Suction Cup of Wall-climbing Robots

The adhering capability, one of the most important performance indexes of wall-climbing robots(WCRs), should be taken into account when a WCR is designed. This paper proposes a novel approach for investigating the adhering characteristics of the sliding suction cup (SSCs) using fluid network theory to enhance the adhering capability of WCRs. The fluid models of the SSCs of two WCRs are developed and equivalent circuits in three cases are presented. The dynamic responses of negative pressure in SSCs are obtained and validated by a set of experiments. It indicated that the theoretical analysis is reasonable and can give some valuable design criteria on the structure parameters of SSCs and control strategies of suction force of SSCs.

Bio-inspired Miniature Suction Cups Actuated by Shape Memory Alloy:

Wall climbing robots using negative pressure suction always employ air pumps which have great noise and large volume. Two prototypes of bio-inspired miniature suction cup actuated by shape memory alloy (SMA) are designed based on studying characteristics of biologic suction apparatuses, and the suction cups in this paper can be used as adhesion mechanisms for miniature wall climbing robots without air pumps. The first prototype with a two-way shape memory effect (TWSME) extension TiNi spring imitates the piston structure of the stalked sucker; the second one actuated by a one way SMA actuator with a bias has a basic structure of stiff margin, guiding element, leader and elastic element. Analytical model of the second prototype is founded considering the constitutive model of the SMA actuator, the deflection of the thin elastic plate under compound load and the thermo-dynamic model of the sealed air cavity. Experiments are done to test their suction characteristics, and the analytical model of the second prototype is simulated on Matlab/simulink platform and validated by experiments.

Operation Principle of a Bend Enhanced Curvature Optical Fiber Sensor

A curvature optical fiber sensor is reported in this paper. The curvature measurement sensitivity is improved using bend enhanced method. The operation principle of this intensity modulate macro-bend curvature optical fiber sensor is proposed based on light scattering theory: the bend of sensitive zone brings about mode coupling and leads to the variation of surface scattering loss. The mathematic model of relationship among light loss, bending curvature, surface roughness and parameters of the fibers configuration is also presented

Design and Optimal Research of a Non-Contact Adjustable Magnetic Adhesion Mechanism for a Wall-Climbing Welding Robot

Wall-climbing welding robots (WCWRs) can replace workers in manufacturing and maintaining large unstructured equipment, such as ships. The adhesion mechanism is the key component of WCWRs. As it is directly related to the robots ability in relation to adsorbing, moving flexibly and obstacle-passing. In this paper, a novel non-contact adjustably magnetic adhesion mechanism is proposed. The magnet suckers are mounted under the robots axils and the sucker and wall are in non-contact. In order to pass obstacles, the sucker and the wheel unit can be pulled up and pushed down by a lifting mechanism. The magnetic adhesion force can be adjusted by changing the height of the gap between the sucker and the wall by the lifting mechanism. In order to increase the adhesion force, the value of the suckers magnetic energy density (MED) is maximized by optimizing the magnet suckers structure parameters with a finite element method. Experiments prove that the magnetic adhesion mechanism has enough adhesion force and that the WCWR can complete wall-climbing work within a large unstructured environment.

A cable-tunnel inspecting robot for dangerous environment

This paper presents a kind of mobile robot used for inspecting the cable tunnel online in the dangerous environment. Usually, the calble tunnel is full of poisonous gases after fire, such as CO, CH4, CO2 and so on. Then, the mobile robot is able to tell us whether the tunnel environment is safe or not. In this paper the architecture of the robot is designed at first to meet the motion requirement in the tunnel. These characteristics distinguish the mobile robot from others like compact structure, small size, little weight and easily being carried. Next, the moving mechanism and its kinematics are described. And thus, the operating procedure and experiments are introuduced to validate its reliablity.

A binocular machine vision system for ball grid array package inspection

Purpose – In this paper, an optical inspection method of the ball grid array package(BGA) is proposed using a binocular machine vision system.Design/methodology/approach – The height of each solder ball is calculated based on spatial geometrical size and location obtained from the two CCD cameras capturing range images of a LED illuminated BGA chip at certain orientation.Findings – The structure of this system is simple and the accuracy is 0.02 mm, The experimental results have proved the validity of this system for BGA failure detection.Practical implications – The developed machine vision system can provide some of the critical factors for BGA quality evaluation, such as the height of solder ball, diameter, pitch and coplanarity.Originality/value – Compared with other systems, the structure of this system is simple and accurate, which meets the demand of off‐line and on‐line inspection. The limitation of this system is that the margin of field of view (FOV) is fuzzy. Further study could be focused on th...

Study on quality control in the bonding processing of space solar cell

The solar cell is widely used for space power. The characteristic of anti-irradiation is one of the important differences between ordinary solar cells and space solar cells. In order to ensure a space solar cell works reliably in the space environment, it is necessary to bond the anti-irradiation cover-glass to the space solar cell active surface using a kind of adhesive, and it is vital to have a reasonable coating thickness. Combining robotics and adhesive-coating technology, this paper gives an automatic bonding system for space solar cells, which can precisely control the coating thickness and realize bonding automation in non-vacuum conditions. Moreover, on the basis of the theory of non-Newtonian fluids, the paper presents a model for this system and deduces the formula for the coating thickness of space solar cells. Experiments have been performed to validate this model.

Design of a Robot End-Effector Grabbing Mechanism Based on a Bionic Snake Mouth

Inspired by the bite and swallowing function of a snakes mouth, a robot end-effector grabbing mechanism was designed. The grabbing movement is realized by the ‘bite’ function of the bionic snake mouth actuator, and the ‘swallowing’ function insures a continuous grip on the object. To implement the continuous grip function of the new robot end-effector, the complex motion of a snakes mouth is simplified into three basic movements based on the anatomy of a snakes mouth and with a combination of bionics and engineering. The upper jaw consists of a double four-bar linkage mechanism and the lower jaw mechanism implementing a lateral expansion function are the two elements of the robot end-effector. The relationship model and the corresponding curves of the actuating force and gripping force are necessary to implement an open-loop control of the robot end-effector. Through analysis and simulation, linkage parameters are determined to implement the desired motion.