Design of an automated sorting and orienting machine for electronic pins

Thesis (M. Eng. in Manufacturing)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012.Cataloged from PDF version of thesis.Includes bibliographical references (p. 93-94).At the power electronics manufacturer SynQor, the printed circuit board (PCB) assembly line is fully automated with the exception of the step which inserts electronic pins into the PCBs. Past attempts to automate this process have resulted in two unreliable machines that are not in use on the production line. Thus, electronic pin insertion is currently a manual process. The design proposed in this thesis for an automated pin insertion system separates the sorting and orienting of the pin from the insertion of the pin into a PCB. This system decoupling allows for more reliable pin delivery, which can in turn increase the insertion speed and reliability. This thesis focuses on sorting and orienting of the pin. The resulting design takes pins from a bulk state to an oriented state and inserts them in a pin holding magazine. Preliminary trials of the system show promise as an efficient way of preparing oriented pins for use by a pin insertion mechanism, but more experimentation is needed to test the robustness and speed of the sorting system.by Michelle Sueway Chang.M.Eng.in Manufacturin

Design and development of an automated pinning machine for the surface mount electronics industry

Thesis (M. Eng. in Manufacturing)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2012."September 2012." Cataloged from PDF version of thesis.Includes bibliographical references (p. 97-99).This thesis describes the development of a concept for a pinning process and the associated machinery to handle odd-form pins specific to a company in the surface mount electronics industry. The developed pinning machine will reduce manual labor requirements, increase flexibility over current automated systems, and allow for greater part traceability. A brief history of industrial automation is presented to establish a background of the industry, followed by a more detailed look at robotic tooling. The design of the automated pinning machine is described in detail, as well as the design methodology behind the sub-systems and components themselves. Finally, the performance of the machine is documented in a testing chapter, comparing machine performance to the original design specifications. The final pinning machine is capable of processing pins with cycle times of 850ms, and has a mean time to failure of 0.24 hours.by Daniel J. Cook.M.Eng.in Manufacturin

On the design of multi-platform parallel mechanisms

Parallel mechanisms have been examined in more and more detail over the past two decades. Parallel mechanisms are essentially the same design layout, a base, multiple legs/limbs, and a moving platform with a single end-effector to allow the mechanism to complete its desired function. Recently, several research groups have begun looking into multiple-platform parallel mechanisms and/or multiple end-effectors for parallel mechanisms. The reason for the research in this new form of parallel mechanism stems from multiple sources, such as applications that would require multiple handling points being accessed simultaneously, a more controlled gripper motion by having the jaws of the gripper being attached at different platforms, or to increasing the workload of the mechanism. The aim of the thesis is to modify the design process of parallel mechanisms so that it will support the development of a new parallel mechanism with multiple platforms capable of moving relative to each other in at least 1-DOF and to analyse the improvements made on the traditional single platform mechanism through a comparison of the power requirements for each mechanism. Throughout the thesis, a modified approach to the type synthesis of a parallel mechanism with multiple moving platforms is proposed and used to create several case study mechanisms. Additionally, this thesis presents a new series of methods for determining the workspace, inverse kinematic and dynamic models, and the integration of these systems into the design of a control system. All methods are vetted through case studies where they are judged based on the results gained from existing published data. Lastly, the concepts in this thesis are combined to produce a physical multi-platform parallel mechanism case study with the process being developed at each stage. Finally, a series of proposed topics of future research are listed along with the limitations and contributions of this work

Advancement in robot programming with specific reference to graphical methods

This research study is concerned with the derivation of advanced robot programming methods. The methods include the use of proprietary simulation modelling and design software tools for the off-line programming of industrial robots. The study has involved the generation of integration software to facilitate the co-operative operation of these software tools. The three major researcli'themes7of "ease of usage", calibration and the integration of product design data have been followed to advance robot programming. The "ease of usage" is concerned with enhancements in the man-machine interface for robo t simulation systems in terms of computer assisted solid modelling and computer assisted task generation. Robot simulation models represent an idealised situation, and any off-line robot programs generated from'them may contain'discrepancies which could seriously effect thq programs' performance; Calibration techniques have therefore been investigated as 'a method of overcoming discrepancies between the simulation model and the real world. At the present time, most computer aided design systems operate as isolated islands of computer technology, whereas their product databases should be used to support decision making processes and ultimately facilitate the generation of machine programs. Thus the integration of product design data has been studied as an important step towards truly computer integrated manufacturing. The functionality of the three areas of study have been generalised and form the basis for recommended enhancements to future robot programming systems

Force sensing enhancement of robot system

At present there is a general industrial need to improve robot performance. Force feedback, which involves sensing and actuation, is one means of improving the relative position between the workpiece and the end-effector. In this research work various causes of errors and poor robot performance are identified. Several methods of improving the performance of robotic systems are discussed. As a result of this research, a system was developed which is interposed between the wrist and the gripper of the manipulator. This system integrates a force sensor with a micro-manipulator, via an electronic control unit, with a micro-computer to enhance a robot system. The force sensor, the micromanipulator and the electronic control unit, were all designed and manufactured at the robotic centre of Middlesex Polytechnic. The force feedback is provided by means of strain gauges and the associated bridge circuitry. Control algorithms which define the relationship between the force detected and the motion required are implemented in the software. The software is capable of performing two specific tasks in real time, these are: 1- Inserting a peg into a hole 2- Following an unknown geometric path A rig was designed and manufactured to enable the robot to follow different geometric shapes and paths in which force control was achieved mainly by control of the micro-manipulator

Robotic computer–aided tuning of multi-cavity RF filters

Due to the demand for precision RF filter solutions, fully automated cavity filter manufacturing systems are a topic of interest for researchers. Currently, tuning stages for filter production lines are implemented by hand. This stringent process is both expensive and time consuming. Depending on the complexity of the cavity filter, this process may take up to several hours. Therefore, it is not suitable for higher volume production. To overcome this problem, Radio Frequency Systems (RFS Pty Ltd.) company is trying to develop a number of automated filter manufacturing systems that make the leap from conventional ‘trial and error’ manual filter tuning to automatic robotic tuning and set a new standard for filter production. The aim of this project, supported by RFS, is to design and manufacture a Robotic Computer-Aided Tuning (RoboCAT) system. The first section of this thesis deals with the design and fabrication of an automated robot arm to interface with tuning elements. For this purpose, a customised coaxial screw/nut driver is created to tune and lock the tuning elements simultaneously. Aspects of the automated tuner include: (1) Backlash compensation to increase the tuning resolution and reduce the tuning time. (2) Absolute positioning in order to have a second feedback source for robot codes along with obtained data from Computer–Aided Tuning (CAT) software. (3) Fault recognition ability to detect any potential error in CAT codes in early stage. The second stage of this project deals with finding a proper tuning instruction. By having a complete tuning instruction, it is feasible to write a standalone tuning code for an automated tuning system. It can be concluded from literature that circuit model parameter extraction is the only ideal tuning technique to be implemented by automated setup. This technique allows all elements to be tuned simultaneously rather than sequentially. However, in order to tune the filter using this technique, adequate initial optimization variable values are required to prevent the system from running into local minimum or failing to converge to the proper solution. This case arises when the filter is highly detuned. To overcome this problem, a coarse tuning technique based on phase format of input reflection coefficient of the filter is proposed in this thesis. In this method, resonators are tuned by bringing successive resonators to resonance, while the phase passes through the ±180˚ and 0˚ crossing at the center frequency. At the end of each sequence cross coupling is mapped across the entire range of its motion. Tuned cross coupling is recognized by measuring the return loss of the filter. Written codes based on this technique are able to guide the robot through coarse tuning process in a short time. Then, the circuit model parameter extraction technique is practically implemented by automated setup to complete the tuning. This proposed tuning system has been validated through experimental results. Results showed that utilizing the backlash compensation solution enables the robot to use accurate ‘1’ arcminute rotational resolution to achieve less than ‘5’ KHz frequency deviation in obtained filter response. This cannot be achieved with manual tuning. Elimination of mapping the tuning elements throughout the lash reduced the overall tuning time by 11 minutes and 23 seconds in an average of twenty tuning attempts. Absolute positioning system of the RoboCAT successfully detected the faulty tuning attempts caused by an error in CAT software. This enabled the robot to be function without supervision. Fabricated comprehensive coaxial/screw nut driver fitted with the designed SCARA, Cartesian, and multi-armed robots in order to tune the different filter types in the company without need for design updates. Several tuning attempts have been performed by the automated setup utilizing the proposed coarse tuning technique. Obtained filter response at the end of each tuning was very close to the ideal filter response. Therefore perfect initial values for the variables to be optimized were provided for the fine tuning program. This reduced the fine tuning time from 13 minute to less than 32 seconds and prevented the system from running into local minimum. Successful results in all tuning runs showed effectiveness of the tuning technique. Obtained tuning times via created setup was compared with traditional manual tuning attempts. RoboCAT achieved a tuned filter with an average time of 6 minutes compared to the manual tuning approach which took 42 minutes. These results obtained from 20 tuning attempt on a six-pole cross-coupled filter while the filter was tuned to channel 40 at a center frequency of 613.5 MHz

Parameter identification and model based control of direct drive robots

Imperial Users onl