Part Feeding Research Articles

Part Identification System for a Flexible Feeder using Proximity Sensors

<p>A part feeder intakes identical parts of arbitrary orientation and provides output in uniform orientation. A flexible feeder is capable of handling parts of several sizes. The two important modules of a flexible part feeder are (i) identification of part (ii) adjustments to accommodate the incoming part. This paper aims at first module i.e. developing a low cost part identification system using two proximity sensors and thereby eliminating the use of costlier vision systems. The proposed part identification system using two capacitive type proximity sensors was effective in identifying the size of incoming parts and the efficiency of the system was around 84.6%.</p>

The Secret of Gambling with Irregular Dice: Estimating the Face Statistics of Polyhedra

This paper is devoted to the description of a new geometric algorithm to estimate the “face statistics” of an irregularly-shaped polyhedron, i.e. the probability that it rests on a given face after being dropped onto a horizontal surface. A recently published paper of the author discussed existing and new methods to estimate this probability, together with a comparison of their reliability, and the challenges of benchmarking them against data obtained via computer simulation. The present work focuses on a new estimation algorithm, with computational complexity linearly proportional to the number of vertices. The main industrial application area of this result is automated assembly: the throughput of a part feeder is heavily influenced by the face statistics of the parts processed by the feeder.

Estimating Part Pose Statistics With Application to Industrial Parts Feeding and Shape Design: New Metrics, Algorithms, Simulation Experiments and Datasets

Part feeders take an unsorted bulk of identical parts and output them in a uniform orientation. Common feeders sort out those items that settle initially on one specific face, and further reorient them as desired. Quick estimators of the probability of settling on a given face facilitate the design of parts for efficient feeding and of the feeding lines themselves. Nevertheless, the evaluation and the development of such estimators have been hindered by the lack of data. Here, I create and analyze a large, simulated dataset; evaluate estimators available in the literature by comparing their predictions to simulation results with the help of a custom-made metric; and propose new estimation algorithms. The new estimators offer viable alternative to the direct dynamic simulation of parts due to their low average errors.

A Drop Test for Finding the most Probable Resting Orientation of a Part

The material handling is the art of moving, orienting, packing and storing the part. Industrial feeders are used to facilitate the operations by feeding the parts in a specific quantity and at a perfect orientation. It is a tedious task to obtain a particular part orientation, at the assembly station, in a short lead time. To overcome this problem, part feeders are used to segregate and orient parts prior to packing. The natural resting orientation of the part is the orientation in which the part rests on a horizontal hard surface, when dropped from a height. The most probable natural resting orientation of the part has to be identified which helps in the effective design of feeder and orienting devices. In this paper, an attempt was made to study the effect of initial orientation from different heights on natural resting orientation. Drop test was conducted at different heights with each initial orientation. The favorable orientation of the part (or) the most probable natural resting orientation is identified using drop test. In this work, most probable natural resting orientation of a typical asymmetric component, brake pad, is identified.

Design and Development of a Singularizing Unit for Part Feeding System

AbstractIn the modern industrial world, speed, agility, accuracy and less time are the key factors to attain a position in the market. Various forms of the products manufactured which could either be symmetric or asymmetric. The stacking of the asymmetric parts are either done manually which is a time-consuming job or by installing robots which are costly. To overcome this problem, part feeders are introduced to stack the parts in a specific orientation. In the automotive industry the brake pads are the components manufactured in a large scale. The manufacture of components and stacking them is an intensive task which necessitates agile manufacturing. So a linear part feeding system is designed along with the trap and conveyor system to reorient the asymmetric part to its most favorable orientation for stacking. The major problem arrives in part feeding system is to send parts one by one to trap. The main objective of this work is to design and develop the singularizing unit for sending the parts one by one. The system is designed to separate the brake pads from clusters and singularize them. The singularizing unit is designed by using Markov model and the unit is fabricated. Experiments were conducted for selecting the suitable parameters by making the unit at various levels of inclinations by using base plates of various thicknesses. The parameters which are concentrated while orienting the parts are frequency of vibration, time to travel the part on the singularizing unit and acceleration of the part for effective part motion in a singularizing unit.

Trap based part feeding system for stacking sector shaped parts

Part feeders have been used in the industries for a long time to present the parts in a desired orientation. A prominent problem in manufacturing automation is the accurate and reliable presentation of small parts, in a single specified configuration called preferred orientation. In this paper, a part feeding system for handling brakeliner, a typical asymmetric component, is discussed. Paul Berretty et al. [12] discussed a class of mechanical filters that can remove polygonal sections from the track of the feeder. They referred to this class of filters as traps, which eliminate or reorient the parts until they reach the final desired orientation. The proposed part feeder was developed using mechanical barriers called trap, to reorient the parts to desired orientation. The desired orientation was the most probable natural resting orientation, which was found using drop test. The proposed low cost part feeder system uses sensorless mechanical devices or barriers such as wiper blade, guiding block, edge riser etc., to reorient the arbitrary orientation into a preferred orientation, which facilitates stacking. Critical dimensions of the trap and appropriate feeding parameters of linear vibratory feeder for maximum conveying velocity were identified experimentally. A system which stacks the parts coming out of the trap was also developed. An expression relating the conveying velocity as a function of vibration amplitude, excitation frequency of vibration and trap inclination angle was obtained through regression analysis. The trap inclination angle was found to be the most significant factor, on conveying velocity. The proposed set-up reduced the time taken for stacking 80 parts by about 13.5 %.

Determining the most probable natural resting orientation of sector shaped parts

PurposeIdentifying the most probable natural resting orientation of a part, in automatic handling, helps in the effective design of feeder and orientation devices. For parts with complex geometries and topologies, it is not always intuitively apparent what the natural resting probability of each orientation is. The purpose of this paper is to determine, by theoretical methods, the probability of occurrence of each natural resting orientation of eight different typical sector shaped parts.Design/methodology/approachProbability of natural resting orientations were found using theoretical methods and drop test. Pearson's χ 2 test was used to decide whether to accept or reject the expected data by comparing with the observed data.FindingsIrrespective of dimensions and material, the most probable natural resting orientation was the same. Height of drop was influential in the probability of most probable natural resting orientation.Research limitations/implicationsThe research does not include objects with minimum thickness (i.e. 2D objects).Originality/valueThe paper shows that determining the most probable natural resting orientation will help designers to design the part feeders effectively.

Modelling and Scheduling Autonomous Mobile Robot for a Real-World Industrial Application

The paper deals with a real-world implementation of an autonomous industrial mobile robot performing an industrial application at a pump manufacturing factory. In the implementation, the multi-criteria optimization problem of scheduling tasks of a mobile robot is taken into account. The paper proposes an approach composing of: a mobile robot system design (“Little Helper”), an appropriate and comprehensive industrial application (multiple-part feeding tasks), an implementation concept for industrial environments (the bartender concept), and a real-time heuristics integrated into Mission Planning and Control software to schedule the mobile robot in the industrial application. Results from the real-world implementation show that “Little Helper” is capable of successfully serving four part feeders in three production cells within a given planning horizon using the best schedule generated from the realtime heuristics. The results also demonstrated that the proposed real-time heuristics is capable of finding the best schedule in online production mode.

Determining the natural resting orientation of a part using drop test and theoretical methods

Part feeder is used in automated assembly lines to segregate and orient parts prior to packing. Trap is the heart of the part feeding system to change possible orientations to natural resting orientation. For designing the trap, the natural resting orientation or favorable orientation of a component must be understood. The favorable orientation of the part is the orientation in which the part rests on a horizontal surface. The natural resting orientation of a part is identified using a drop test. By dropping a part from different heights the orientation of the part is noted after it comes to rest. The most probable occurrence of orientation is considered as favorable orientation of part. The obtained favorable orientation through drop test is also compared with the likely orientations identified through theoretical methods like energy barrier method, centroid solid angle method, stability method and critical solid angle method. It is found that the orientation obtained through drop test matches with the results of three theoretical methods. In this work, the natural resting orientation of a typical asymmetric component, brake pad, is identified.

Multiple part feeding – real‐world application for mobile manipulators

PurposeThe purpose of this paper is to present experience from a real‐world demonstration of autonomous industrial mobile manipulation (AIMM) based on the mobile manipulator “Little Helper” performing multiple part feeding at the pump manufacturer Grundfos A/S.Design/methodology/approachThe necessary AIMM technologies exist at a mature level – the reason that no mobile manipulators have yet been implemented in industrial environments, is that research in the right applications have not been carried out. The paper proposes a pragmatic approach consisting of: a commercial‐off‐the‐shelf (COTS) mobile manipulator system design (“Little Helper”), a suitable and comprehensive industrial application (multiple part feeding), and a general implementation concept for industrial environments (the “Bartender Concept”).FindingsResults from the three days of real‐world demonstration show that “Little Helper” is capable of successfully servicing four part feeders in three production cells using command signals from an Open Process Control (OPC) server. Furthermore, the paper presents future research and development suggestions for AIMM, which contributes to near‐term industrial maturation and implementation.Originality/valueThe paper presents a full‐scale demonstration of a state‐of‐the‐art COTS autonomous mobile manipulator system with particular focus on industrial utilization and application.

Fuel Cell ASAP: Two Iterations of an Automated Stack Assembly Process and Ramifications for Fuel Cell Design-for-Manufacture Considerations

Polymer-electrode membrane fuel cell technology, a low-emission power source receiving much attention for its efficiency, will need to progress from low-volume production to high-volume within the course of the next decade. To successfully achieve this transition, significant research progress has already been made toward developing a fully functional fuel cell automatic stack assembly robotic station. Lessons can be drawn from this research with regards to design-for-manufacture (DFM) and design-for-assembly (DFA) considerations of fuel cells; however, more work still remains to be done. This document outlines both iterations of the robotic fuel cell assembly stations, other work to date, DFM and DFA lessons learned, and the anticipated future progression of automatic fuel cell stack assembly stations. Two individual robotic fuel cell assembly stations were constructed, including custom-built end effectors and part feeders. The second station incorporated numerous improvements, including overlapping work envelopes, elimination of a shuttle cart, software synchronization, fewer axes, and a better end effector. Consequentially, the second workcell achieved a fourfold improvement in cycle time over the previous iteration. Future improvements will focus in part upon improving the reliability of the overall system. As the stack assembly workcell continues to improve, research will focus upon the ramifications and interplay of tolerances, stack failure modes, sealing, reliability, and the potential for component redesign specifically to optimize fuel cell manufacturing throughput.

Ascorbic acid, β-carotene, sugars, phenols, and heavy metals in sweet potatoes grown in soil fertilized with municipal sewage sludge

Municipal sewage sludge (MSS) used for land farming typically contains heavy metals that might impact crop quality and human health. A completely randomized experimental design with three treatments (six replicates each) was used to monitor the impact of mixing native soil with MSS or yard waste (YW) mixed with MSS (YW +MSS) on: i) sweet potato yield and quality; ii) concentration of seven heavy metals (Cd, Cr, Mo, Cu, Zn, Pb, and Ni) in sweet potato plant parts (edible roots, leaves, stem, and feeder roots); and iii) concentrations of ascorbic acid, total phenols, free sugars, and β-carotene in sweet potato edible roots at harvest. Soil samples were collected and analyzed for total and extractable metals using two extraction procedures, concentrated nitric acid (to extract total metals from soil) as well as CaCl2 solution (to extract soluble metals in soil that are available to plants), respectively. Elemental analyses were performed using inductively coupled plasma mass spectrometry (ICP-MS). Overall, plant available metals were greater in soils amended with MSS compared to control plots. Concentration of Pb was greater in YW than MSS amendments. Total concentrations of Pb, Ni, and Cr were greater in plants grown in MSS+YW treatments compared to control plants. MSS+YW treatments increased sweet potato yield, ascorbic acid, soluble sugars, and phenols in edible roots by 53, 28, 27, and 48%, respectively compared to plants grown in native soil. B-carotene concentration (157.5 μg g−1 fresh weight) was greater in the roots of plants grown in MSS compared to roots of plants grown in MSS+YW treatments (99.9 μg g−1 fresh weight). Concentration of heavy metals in MSS-amended soil and in sweet potato roots were below their respective permissible limits.

Noise generated by Electronic Parts Feeder and its Abatement

Noise generated by Electronic Parts Feeder and its Abatement

Optimizing robotic part feeder throughput with queueing theory

Purpose – This paper aims to study a commercially available industrial part feeder that uses an industrial robot arm and computer vision system. Three conveyor belts are arranged to singulate and circulate parts, bringing them under a camera where their pose is recognized and subsequently manipulated by the robot arm. The problem is addressed of optimizing belt speeds and hence throughput of this feeder that avoid: starvation, where no parts are visible to the camera and saturation, where too many parts prevent part pose detection or grasping.Design/methodology/approach – Models are developed for intermittent and continuous motion feeding based on a 2D Poisson process. Renewal theory is applied to model intermittent motion and an M/G/1 queue with customer impatience to model continuous motion feeding. These models are verified using discrete event simulation.Findings – The models predict and optimize feeder behaviour very accurately and it is possible to compute optimal settings for different part sizes a...

Dynamic modeling and experimental verification of a piezoelectric part feeder in a structure with parallel bimorph beams

The study is aimed to perform dynamic modeling of a part feeder powered by piezoelectric actuation. This part feeder consists mainly of a horizontal platform vibrated by a pair of parallel piezoelectric bimorph beams. Owing to intermittent impacts with the platform, the transported part on the platform is able to march forward from one end to another. Dynamic modeling of the feeder is accomplished by essentially using the Rayleigh–Ritz decomposition method. The process of modeling first incorporates material properties and constitutive equations of the piezoelectric materials, and then captures the complex dynamics of the parallel-beam piezo-feeder by three low-order assumed-modes in the transverse direction of the vibrating beams. Applying Lagrange’s equations on the kinetic and strain energies formulated in terms of generalized coordinates associated with the first three modes, the system dynamics is then represented by three coupled discrete equations of motion. Based on these equations, motions of the platform can be obtained. With platform motion in hand, the intermittent impacts between the parts and the platform are modeled, rendering the marching speed of the part. Numerical simulations are conducted along with the experiments. The closeness found between the theoretical predicted transporting speed of the part and the experimental counterparts verify the effectiveness of the models established.

A Study of Vibratory Conveyance by Cam Curve (High Speed Conveyance of the Cam-driven Parts Feeder)

A Study of Vibratory Conveyance by Cam Curve (High Speed Conveyance of the Cam-driven Parts Feeder)

A Near-Quadratic Algorithm for Fence Design

A part feeder is a mechanism that receives a stream of identical parts in arbitrary orientations and outputs them oriented the same way. Various sensorless part feeders have been proposed in the literature. The feeder we consider consists of a sequence of fences that extend partway across a conveyor belt; a polygonal part P carried by the belt is reoriented by each fence it encounters. We present an O(m + n2 log3n)-time algorithm to compute a sequence of fences that uniquely orients P, if one exists, where m is the total number of vertices and n is the number of stable edges of P. We reduce the problem to searching for a path in a state graph that has O(n3) edges. By exploiting various geometric properties of this graph, we show that it can be represented implicitly and that a desired path can be computed in O(m + n2 log3n) time. We believe that our technique is quite general and could be applicable to other part-manipulation problems as well.

Modeling and control of a universal part feeder

The modeling and motion control of a universal part feeder is addressed. The feeder consists of a flat plate (or called bed) and a part placed on the plate. The bed can vibrate side-by-side (in x axis), back and forth (in y axis), clockwise and counter clockwise (about z axis), actuated by three linear motors (voice coils). When the bed does these vibrations, the part placed on the plat will have position and/or orientation change due to the interaction between the two contact surfaces. By controlling the ways in which the plate vibrates, the position and orientation of the part can be controlled. The two vibration profiles of the bed are investigated in the research: the high-low vibration mode and the bang-bang vibration mode. The motion equations of the bed and the part as well as the control schemes for the high-low vibration mode are presented. Both simulation and real-time testing verify the system's dynamic model and indicate the feasibilities of the developed control laws.

A new type of parts feeder driven by bimorph piezo actuator

A novel meander-line structure implemented with bimorph piezoelectric actuators driven by two sets of alternating current power with phase difference is developed in this article. Via the generated traveling wave, this mechanism is able to transport parts. The dynamic modeling of the structure, the driving control circuitry design, the motion trajectory analysis and the optimal transport feed rate is studied, and also verified by the practical experiment.

Mini assembly cell for the assembly of mini‐sized planetary gearheads

This paper discusses a novel assembly method and system for a commercially available 8 mm diameter miniature planetary gearhead. Our system comprises a commercially available four‐degree of freedom industrial robot, two vision systems, a force feedback system in the robot wrist, and specially designed flexible part feeders. The system has proved successful in assembling planetary gear units independently. Depending on the task, one can select whether to use the high accuracy and repeatability of the robot or alternatively use programmable frequency vibration in the gripper to stochastically align the parts that the robot handles.