No description available.

During micro packaging process, the products are almost manufactured by hand work. The development of the micro packaging system can reduce human error and automatic process is implemented. This paper describes a method of motion planning of sliding, and rotating manipulations by a adjustable gripper. In precision assembly tasks such as a screw insertion, the task accuracy required for each direction in the task space is different. This paper discusses the adjustable gripper applied on automatic assembly system. The accurate determination of the position and shape of the objects are analyzed and identified by machine vision. The package time is reduced and the product yield rate is raised.

Industrial robots are very popular in now day’s automation factories, industrial robots can perform jobs that people are not willing or able to perform. Industrial robots can repeat the same work at the exactly same way, resulting a higher quality of production.  Industrial robots can work in several areas, each robot must have a specific tool for each area. This thesis includes design of a gripper tool for an industrial robot for picking and placing different laser notched generator-parts. The product is being designed for the division of electricity in Uppsala University. A gripper tool prototype might be built in the future. The report begins with a theoretical comparison between lifting and gripping techniques for later deciding which technique is most suitable for picking and placing the different parts. A pre-study and a short description about different transporting systems have been made. After the pre-study different concepts were developed, the best suitable concept was selected for further development and final construction. The final design of the gripper tool was used in the robot cell-simulation program ABB Robot Studio for choosing a proper cell design. The gripper tool was designed in light weight material aluminium, and uses electromagnets for picking and releasing the different notched part.  The gripper tool is assembled on an industrial robot from ABB, IRB 7600 with a handling capacity of 150 kg and 3.5m reach. / I dagens automatiserade fabriker är industrirobotar väldigt populära, då industrirobotar kan utföra arbeten som människor inte vill eller kan utföra.  Industrirobotar kan utföra samma arbete flera gånger om på exakt samma sätt, vilket medför en högre kvalitet på produktionen. Industrirobotar kan arbeta inom flera olika områden, för varje område måste industrirobotarna vara utrustade med ett speciellt verktyg. I detta examensarbete designas ett gripdon för en industrirobot som skall plocka och placera olika laserskurna generatordetaljer. Produkten designas för Avdelningen för Elektricitetslära vid Uppsala Universitet. En prototyp av gripdonet kan bli aktuellt i framtiden. Arbetet inleddes med en teoretisk jämförelse mellan olika grepp- och lyfttekniker för att sedan avgöra vilken grepp- respektive lyftteknik passar bäst för plockning och placering av de olika detaljerna. Förstudie och en kort beskrivning av olika transportmetoder ingår. Efter förstudien togs olika möjliga koncept fram för att sedan välja ut det bäst passande konceptet för ytterligare utveckling och en slutlig konstruktion. Den slutliga designen användes seden i robotcellsimuleringsprogrammet ABB Robot Studio för utförandet av experimenten. Gripdonet designades i aluminium och använder elektromagneter som lyftteknik för plockning och placering av de olika skurna plåtdetaljerna. Gripdonet monteras sedan på en industrirobot från ABB, IRB 7600 med lastkapaciteten 150 kg och en räckvidd på 3.5 m.

We consider here a class of mechanisms consisting of one or more compliant members, the manipulation of which relies on the deflection of those members. Compared with traditional rigid-body mechanisms, compliant mechanisms have the advantages of no relative moving parts and thus involve no wear, backlash, noises and lubrication. Motivated by the need in food processing industry, this paper presents the Global Coordinate Model (GCM) and the generalized shooting method (GSM) as a numerical solver for analyzing compliant mechanisms consisting of members that may be initially straight or curved. As the name suggests, the advantage of global coordinate model is that all the members share the same reference frame, and hence, greatly simplifies the formulation for multi-link and multi-axis compliant mechanisms. The GCM presents a systematic procedure with forward/inverse models for analyzing generic compliant mechanisms. Dynamic and static examples will be given and verified experimentally. We also develop the Generalized Shooting Method (GSM) to efficiently solve the equations given by the GCM. Unlike FD or FE methods that rely on fine discretization of beam members to improve its accuracy, the generalized SM that treats the boundary value problem (BVP) as an initial value problem can achieve higher-order accuracy relatively easily. Using the GCM, we also presents a formulation based on the Nonlinear Constrained Optimization (NCO) techniques to analyze contact problems of compliant grippers. For a planar problem it essentially reduces the domain of discretization by one dimension. Hence it requires simpler formulation and is computationally more efficient than other methods such as finite element analysis. An immediate application for this research is the automated live-bird transfer system developed at Georgia Tech. Success to this development is the design of compliant mechanisms that can accommodate different sizes of birds without damage to them. The feature to be monolithic also makes complaint mechanisms attracting in harsh environments such as food processing plants. Compliant mechanisms can also be easily miniaturized and show great promise in microelectromechanical systems (MEMS). It is expected that the model presented here will have a wide spectrum of applications and will effectively facilitate the process of design and optimization of compliant mechanisms.

No description available.

This thesis details an innovative laser diode packaging method to improve the accuracy of the laser locator by modifying the location method and packaging process. This method features its simplicity in the packaging process, the capability in tweaking the rotary angle of the laser diode, and an effective solution to the scaling effect as well as the enhancement in yield. The gripping micro-unit,consisting of a refined micro gripper together with the piezoelectric actuator and coupler,integrates a self-designed rotary adjustment and release unit to enable the micro-rectangle unit such as a laser unit to fine tune the location of the object. It works with the linear stage, platform, and image acquisition system to become the core of the proposed location system. A series of experiments are designed to verify the functionality. A precise linear stage without the rotary axis is applied to control the locator,adjust the location of the laser, and minimize the error from equipment. The result demonstrates its feasibility.

Smart materials have been widely used for control actuation. A robotic hand can be equipped with artificial tendons and sensors for the operation of its various joints mimicking human-hand motions. The motors in the robotic hand could be replaced with novel electroactive-polymer (EAP) actuators. In the three-finger gripper proposed in this paper, each finger can be actuated individually so that dexterous handling is possible, allowing precise manipulation. In this dissertation, a microscale position-control system using a novel EAP is presented. A third-order model was developed based on the system identification of the EAP actuator with an AutoRegresive Moving Average with eXogenous input (ARMAX) method using a chirp signal input from 0.01 Hz to 1 Hz limited to 7 ± V. With the developed plant model, a digital PID (proportional-integral-derivative) controller was designed with an integrator anti-windup scheme. Test results on macro (0.8-mm) and micro (50-μm) step responses of the EAP actuator are provided in this dissertation and its position tracking capability is demonstrated. The overshoot decreased from 79.7% to 37.1%, and the control effort decreased by 16.3%. The settling time decreased from 1.79 s to 1.61 s. The controller with the anti-windup scheme effectively reduced the degradation in the system performance due to actuator saturation. EAP microgrippers based on the control scheme presented in this paper will have significant applications including picking-and-placing micro-sized objects or as medical instruments. To develop model-based control laws, we introduced an approximated linear model that represents the electromechanical behavior of the gripper fingers. Several chirp voltage signal inputs were applied to excite the IPMC (ionic polymer metal composite) fingers in the interesting frequency range of [0.01 Hz, 5 Hz] for 40 s at a sampling frequency of 250 Hz. The approximated linear Box-Jenkins (BJ) model was well matched with the model obtained using a stochastic power-spectral method. With feedback control, the large overshoot, rise time, and settling time associated with the inherent material properties were reduced. The motions of the IPMC fingers in the microgripper were coordinated to pick, move, and release a macro- or micro-part. The precise manipulation of this three-finger gripper was successfully demonstrated with experimental closed-loop responses.

Deadlocks are critical events in Flexible Manufacturing Cells (FMC) that result from circular waits among a set of resources. Circular waits happen when a set of resources with finite capacity are in a permanent hold due to wait state to admit new jobs. Past literature examines the deadlock-free scheduling in FMCs considering many types of resources and techniques. This thesis proposes a new resource-oriented deadlock-free approach using a robot equipped with dual-grippers serving as a material handler in a FMC. The proposed methodology uses Constraint Programming (CP). The system performance is analyzed using different buffer configurations. Many test problems are generated to validate the developed models. The finding demonstrates that the proposed dual-gripper robot (DGR) can outperform the single-gripper robot (SGR) in many settings for FMCs. Likewise, the experience with the CP for the modeling and solving approach proposed in this research consolidates its application to FMC deadlock-free scheduling problems.

Deadlocks are critical events in Flexible Manufacturing Cells (FMC) that result from circular waits among a set of resources. Circular waits happen when a set of resources with finite capacity are in a permanent hold due to wait state to admit new jobs. Past literature examines the deadlock-free scheduling in FMCs considering many types of resources and techniques. This thesis proposes a new resource-oriented deadlock-free approach using a robot equipped with dual-grippers serving as a material handler in a FMC. The proposed methodology uses Constraint Programming (CP). The system performance is analyzed using different buffer configurations. Many test problems are generated to validate the developed models. The finding demonstrates that the proposed dual-gripper robot (DGR) can outperform the single-gripper robot (SGR) in many settings for FMCs. Likewise, the experience with the CP for the modeling and solving approach proposed in this research consolidates its application to FMC deadlock-free scheduling problems.

Automation of the industrial transformer core assembly process is highly desirable. A survey undertaken by the author however, revealed that due to the high cost of existing fully automated systems, Australian manufacturers producing low to medium transformer volumes continue to maintain a manual construction approach. The conceptual design of a cost-effective automation system for core assembly from pre-cut lamination stacks was consequently undertaken. The major hurdle for automating the existing manual process was identified as the difficulty in reliably handling and accurately positioning the constituent core laminations, which number in their thousands, during transformer core construction. Technical evaluation of the proposed pick-and-place core assembly system, incorporating two mobile robots bearing a common gripper, is presented herein to address these requirements. A unique robotic gripper, having the capability to selectively pick a given number of steel laminations (typically two or three) concurrently from a stack, has the potential to significantly increase productivity. The only available avenue for picking multiple laminations was deemed to be a gripper based on magnetism. Closed form analytical and finite element models for an electromagnet-stack system were contrived and their force distributions obtained. The theoretical findings were validated by experiment using a specially constructed prototype. Critical parameters for reliably lifting the required number of laminations were identified and a full scale electromagnet, that overcame inherent suction forces present in the stack during picking, was subsequently developed. A mechanical docking arrangement is envisaged that will ensure precise lamination placement. Owing to the grippers unwieldy length however, conventional robots cannot be used for assembling larger cores. Two wheeled mobile robots (WMRs) compliantly coupled to either end of the gripper could be considered although a review of the current literature revealed the absence of a suitable controller. Dynamic modelling for a single WMR was therefore undertaken and later expanded upon for the dual WMR system conceived. Nonlinear adaptive controllers for both WMR systems were developed and subsequently investigated via simulation. Neglecting the systems dynamics resulted in analogous, simplified kinematic control schemes, that were verified experimentally using prototypes. Additional cooperative control laws ensuring the synchronisation of the two robots were also implemented on the prototype system.