Machine Guidance Research Articles

Massive Sensor Array Fault Tolerance: Tolerance Mechanism and Fault Injection for Validation

As today's machines become increasingly complex in order to handle intricate tasks, the number of sensors must increase for intelligent operations. Given the large number of sensors, detecting, isolating, and then tolerating faulty sensors is especially important. In this paper, we propose fault tolerance architecture suitable for a massive sensor array often found in highly advanced systems such as autonomous robots. One example is the sensitive skin, a type of massive sensor array. The objective of the sensitive skin is autonomous guidance of machines in unknown environments, requiring elongated operations in a remote site. The entirety of such a system needs to be able to work remotely without human attendance for an extended period of time. To that end, we propose a fault-tolerant architecture whereby component and analytical redundancies are integrated cohesively for effective failure tolerance of a massive array type sensor or sensor system. In addition, we discuss the evaluation results of the proposed tolerance scheme by means of fault injection and validation analysis as a measure of system reliability and performance.

Planning the Implementation of Three-Dimensional Technologies for Design and Construction

The Wisconsin Department of Transportation (DOT) has developed a specification for highway subgrade construction by automated machine guidance (AMG). Wisconsin DOT is also deploying new design software, capable of providing three-dimensional (3-D) models required for AMG. During 2008, Wisconsin DOT, with assistance from the Construction and Materials Support Center at the University of Wisconsin–Madison, undertook a study of benefits and impediments to wider use of 3-D information in design and construction. The primary finding of a stakeholder workshop was that 3-D design and AMG are among a larger group of technologies and processes that have interrelated dependencies, synergistic benefits, and shared implementation issues. Thus, the study's objective was expanded to development of a high-level implementation plan for 3-D technologies and methods, in general, for highway design and construction in Wisconsin. The plan presents a vision, a management strategy, and six initiatives, including descriptions of backgrounds, issues, stakeholders, recommendations, goals, timelines, levels of effort, priorities, benefits, relationships with other initiatives, and responsible parties. The initiatives address an ongoing height modernization and continuously operating reference station program; standards, procedures, and training for 3-D data collection; 3-D model content and format standards; additional specifications for AMG; field technology and inspection; and infrastructure life-cycle uses of 3-D data. The plan differentiates between priorities (importance) and precedence (dependencies) among initiatives and goals within them. This information should be beneficial to other state highway agencies considering implementation of 3-D technologies.

Stringless Portland Cement Concrete Paving

This paper describes results from a study evaluating stringless paving using a combination of global positioning and laser technologies. A concrete paver manufacturer and a machine guidance solution provider developed this technology and successfully implemented it on construction earthmoving and grading projects. Concrete paving is a new area for considering this technology. A concrete paving contractor in Iowa agreed to test the stringless paving technology on two challenging concrete paving projects located in Washington County, Iowa during the summer of 2003. The research team from Iowa State University monitored the guidance and elevation conformance to the original design. They employed a combination of physical depth checks, surface location and elevation surveys, concrete yield checks, and physical survey of the control stakes and string line elevations. A final check on profile of the pavement surface was accomplished by the use of the Iowa Department of Transportation Light Weight Surface Analyzer. Due to the speed of paving and the rapid changes in terrain, the laser technology was abandoned for this project. Total control of the guidance and elevation controls on the slip form paver were moved from string line to a global positioning system (GPS). Results indicate that GPS control is a feasible approach to controlling a concrete paver. Further enhancements are needed in the physical features of the slip form paver hydraulic system controls and in the computer program for controlling elevation.

Navigation of construction and agriculture machinery

Over the last two decades terrestrial and global 3D measurement sensors in the field of engineering geodesy have seen a significant upturn. With modern measurement techniques, a 3D trajectory of a moving object can be determined within a few centimetres (mostly with Global Navigation Satellite Systems, GNSS), under certain circumstances and with an overall understanding of the applied method accuracies of 5–10 millimetres can be achieved (tracking total station). New application areas have been now created in the fields of construction, mining and agriculture. The guidance or control of heavy machinery demands a navigation sensor with an appropriate measurement rate and accuracy, as well as stable and reliable performance. The 3D position, together with the orientation as well as the long and cross inclination information is hereby just a part of the absolute machine guidance or control unit. Data collection, verification, management and interaction of the position information with 6 degrees of freedom, together with the machine controller, are needed for the overall system. Rotation ring sensors for height control or height guidance are well-known amongst construction jobs and have been in use for more than 20 years. The first GPS-based guidance system for yield mapping was used 15 years ago (Auernhammer 1995). Optimization and improvements in efficiency are the principal reasons for the current developments in the area of 3D-based machine control and guidance. This paper describes the state-of-the-art and general approaches as well as the real-time 3D measurement techniques in construction and agriculture environment. Article in English Statybų bei žemės ūkio mašinų navigacija Santrauka.  Per pastaruosius dvejus dešimtmečius Žemės paviršiaus bei globaliniai trimačio matavimo jutikliai taikomi inžinerinėje geodezijoje labai ištobulėjo. Modernia matavimų technika trimatė objekto judėjimo trajektorija gali būti nustatyta kelių centimetrų tikslumu (daugiausia globaline navigacine palydovine sistema (GNPS) bei vietinėmis padėties nustatymo sistemomis 5–10 mm tikslumu. Statybų, tunelių kasimo bei žemės ūkio šakose atsirado naujų šių prietaisų taikymo galimybių. Sunkiasvorėms mašinoms valdyti bei kontroliuoti būtini atitinkamos matavimų spartos ir tikslumo, stabiliai ir patikimai veikiantys navigacijos jutikliai. Informacija apie trimatę padėtį, orientavimas bei linijinių ir kampinių poslinkių duomenys šiuo atveju yra tik mašinos valdymo bei kontrolės absoliučiosios sistemos dalis. Bendrajai valdymo sistemai būtinas duomenų rinkimas, tikrinimas, apdorojimas bei informacijos apie padėtį sietis pagal 6 laisvės laipsnius ir su mašinos valdymo įtaisais. Besisukantys žiediniai jutikliai, taikomi aukščių kontrolei, plačiai paplitę statybose, yra naudojami jau daugiau nei 20 metų. Pirmoji GPS paremta derliaus nustatymo valdymo sistema buvo pritaikyta prieš 15 metų (Auernhammer 1995). Darbo efektyvumo didinimas bei optimizavimas yra pagrindinės dabartinių trimatės mašinų kontrolės bei valdymo sistemų tobulinimo sritys. Aprašomi aukštųjų technologijų bei bendrieji matavimų principai, realiojo laiko trimačio matavimo statybose bei žemės ūkyje technologijos.

Sensitivity analysis as a general tool for model optimisation – examples for trajectory estimation

This paper outlines the general characteristics of variance-based sensitivity analysis and their advantages with respect to other concepts of sensitivity analysis. The main benefit are qualitative and quantitative correct results independent of the model characteristics. The author focuses on kinematic positioning as required for car navigation, driver assistance systems or machine guidance. The paper compares two different Kalman filter approaches using variance analysis and variance-based sensitivity analysis. The approaches differ with respect to their measurement quantities (input), their state quantities (output), as well as their dynamic vehicle model. The sensitivity analysis shows that each model has its different advantages and input-output relations. Furthermore it is shown that the variance-based sensitivity analysis is well suited to detect the share of the influence of the input quantities on the output quantities, here the estimated positions. Even more important, changes in deterministic and stochastic models lead to obvious effects in the respective variances and sensitivity measures. This emphasises the possibility to optimise the filter models by use of the variance-based sensitivity analysis.

Engineering Aspects of Production and Harvest Mechanization for Fresh and Processed Vegetables

Production and harvesting systems for processing vegetables have been highly mechanized, however, field efficiencies are generally low, and high field losses and fruit damage continue to limit profits for several crops. By comparison, the number of fresh market crops currently machine harvested is small, and research to develop new harvesting technology for these crops is limited. Current mechanization research includes improvements to existing production systems, development of harvesters for crops currently hand-harvested, and the integration of new technologies into current (and future) production systems. Mechanical harvester-based production systems are evolving that reduce field losses and fruit damage, improve recovery, and decrease the foreign materials in the harvested product. However, improved cultural production systems and crop varieties that are adapted for once-over machine harvest are needed. An integrated approach in which crop characteristics along with planting, cultivating, and harvesting techniques are considered will be necessary to develop profitable and highly efficient alternatives to hand-harvest production. The integration of new technologies including differential global positioning systems (DGPS), automatic machine guidance, and computer-based vision systems offers significant performance benefits, and is a substantial component of current vegetable production and harvesting research in the U.S. In time, as the costs of these technologies decline, commercial adoption of these new methods is expected to increase.

Safety aspects for automatic guidance of agricultural machines and low-cost solutions

Automatic steering devices for farm machinery and tractors have the task to relieve the driver from the physical and mental stress of monotonous steering work. Simultaneously, they are intended to help exploit machines and tractors closer to their full performance and improve the quality of work. However, it is not possible to rule out malfunctions or breakdowns of sensors, gaps in guidance lines, obstacles in the field such as ditches or pylons, temporary hazards like the sudden appearance of animals in front of a moving machine or a temporary lack of concentration of the operator. Most of these problems may be prevented by a safety system for automatically steered agricultural machinery developed at the Department of Agricultural Engineering of the Martin-Luther-University in Halle. The function of the components of the safety system and preliminary results obtained in field experiments are introduced and discussed.

03/01617 Australian mine pioneers new technology for satellite-based machine guidance: Anon., Coal Age, 2003, 108, (3), 30–32

03/01617 Australian mine pioneers new technology for satellite-based machine guidance: Anon., Coal Age, 2003, 108, (3), 30–32

Factors in Productivity and Unit Cost for Advanced Machine Guidance

This paper presents an initial step in seeking to understand just how the adoption of advanced machine guidance technology, especially global positioning systems, leads to improvements in performance by the earthwork contractor. Two grading scenarios and one dozing scenario are examined based upon site observations and interviews with field personnel. Analysis demonstrated that productivity and unit cost improvements result from a reduction in surveying support, grade checking, an increase in operational efficiency, and a decrease in the number of passes. These results are in agreement with published results of benefits of 3D guidance over 2D guidance.

Non‐chemical weed management in organic farming systems

Concern about potential increases in weed populations without the use of herbicides has limited the uptake of organic farming. However, as both public demands for organic produce and the profile of organic farming have increased in recent years, so too has the range of weed control options. Progress in cultural methods of weed control has included the use of novel weed‐suppressing cover crops, and the identification of specific crop traits for weed suppression. Direct weed control has also seen developments, with new implements appearing on the market that could benefit in the future from sophisticated machine guidance and weed detection technology. Advances in novel techniques such as steaming have also been made. Many weed control operations in organic systems present the grower with conflicts, and both these and many of the most recent developments in organic weed control are reviewed. An increase in our understanding of weed biology and population dynamics underpins long‐term improvements in sustainable weed control. The outcome of these studies will benefit conventional and organic growers alike. Emphasis is given to the need for flexibility and a combination of weed biology knowledge, cultural methods and direct weed control to maintain weed populations at manageable levels.

A High-Performance, High-Accuracy RTK GPS Machine Guiadance System

As technology matures, Real Time Kinematic (RTK) global positioning system (GPS) receivers are providing increased performance in accuracy, on-the-fly (OTF) initialization times, measurement speed, and latency. Leica's Dozer 2000 machine guidance system combines an MC1000 GPS sensor, graphic intensive guidance software, a digital terrain model, and a digital site plan. Figure 1 shows the operator's view of the system. The end results is a highly accurate, extremely responsive local navigation system. Engineers can easily upload design information onto a touch-screen machine guidance personal computer (PC) and greatly reduce earthmoving costs while simultaneously recording “as-built” inspection data. The Leica MC1000 machine control sensor is a true 10-Hz, centimeter-level-accuracy, open-architecture GPS sensor specifically designed for machine guidance and control. At the heart of the MC1000's performance are a very stable oven-controlled oscillator (3 × 10−11/s short-term stability), a low-power Intel 486-DX4-80 processor, and four user-configurable input/output (I7O) ports. Special algorithms mitigate the effects of multipath and Selective Availability (SA) while providing centimeter accuracy up to 10 times per second with only 30 milliseconds' latency. The high update rate and low latency are essential for machine guidance and control. The MC1000 GPS reference station is capable of outputting RTK and Differential GPS (DGPS) data simultaneously, providing and entire site with GPS information for machine guidance and control, tracking and dispatching of vehicles, and support of survey crews. This article describes how recent advances in technology have combined to produce the Leica Dozer 2000 – a machine guidance system that is ideal for a wide range of earthmoving and inspection applications. © 2000 John Wiley & Sons, Inc.

Machine vision reaches top gear

The power and simplicity of a new generation of machine vision systems have done much to overcome the automotive industry's reluctance to invest in this technology. Most vision applications in the automotive industry are for machine guidance or quality inspections. In quality control inspections, the vision system determines whether parts or sub-assemblies are acceptable or defective and then directs motion control equipment to reject or accept them. Machine guidance applications use vision systems to improve the accuracy and speed of assembly robots and automated materials handling equipment in several areas. The most advanced machine vision systems enable a robot to locate the part or sub-assembly on which it is working, regardless of rotation or scale. In most applications, machine vision provides real-time data and live feedback to guide robots as they go through programmed sequences of operations. The new generation of vision systems can be trained to look for detailed patterns and shapes that match templates for correctly made subassemblies. Powerful pattern recognition capabilities allow vision systems to find missing material, chips, scratches, dents, misplaced markings and a variety of other flaws. As well as ensuring the quality of finished parts and products, they also enable manufacturers to reduce costs by eliminating defective pieces before wasting additional material and time on them.

Vision helping the automotive industry to better customer choice

The application of vision is providing the automotive industry with greater flexibility. Examines applications in both machine guidance and inspection. Examples of robot guidance from windscreen insertion using 2D data to painting of car bodies, which requires 3D vision. Inspection examples are of body‐in‐white measurement and the quality of rear axle units ready for assembly.

User responses to constraints in computerized design tools (extended abstract)

This study sought to improve our understanding of user attitudes, perceptions, satisfaction and behavior in reference to constraints within computerized design tools. It also attempted to examine the differences in perspective between tool builders and tool users regarding appropriate design practices, as communicated via design tools.The study created a typology of constraints and described a set of strategies users employ in the negotiation of constraints encountered in of computer-aided systems engineering (CASE) tools. Also addressed were (a) the cognitive fit between tool users and tool builders in terms of appropriate and necessary constraints, and (b) issues of creativity in the design of computer software.An eight-page questionnaire containing 61 questions was developed by conducting structured interviews with tool users and managers, in industry. Following a pre-test, the questionnaire was administered to an international sample of tool users, tool builders and non-CASE software application developers (a control group). More than 200 questionnaires were returned (half via electronic mail) from respondents largely in North America, but also from Europe, Australia and New Zealand.Analysis followed a factorial design that evaluated the impact of normative attitudes toward and perceptions of control upon satisfaction and behavior. Most respondents reported not feeling especially encumbered with constraints in their tools, although most also reserved the right to override or work around constraints, depending upon circumstances.The study found that normative attitudes toward control have a significant impact upon behavior in response to constraints in computerized design tools. (Favorable attitudes toward control are associated significantly with conforming behavior.) It also found that perceptions of control have a significant impact upon satisfaction and behavior. (Perceptions of high control are associated significantly with low satisfaction and with resistant behavior.) No significant differences were observed between tool users and tool builders in terms of key constructs.Suggestions for future research include investigation of concerns raised by the current study, examination of similar effects in other domains (such as architectural design), and development of the potential for intelligent machine guidance in creative design activities.

The effect of orderly vibration on pickforce sensing

ABSTRACT Pickforce sensing is a method developed for automating the guidance of coal mining machines. Its objective is to determine the vertical location of a rotary cutting machine from the force measured at the point of contact between the machine and the coal seam. A phenomenon that may degrade the reliability of the pickforce data is vibration, and is the concern of this study. The effects of vibration may either be orderly or chaotic. The focus of this paper is on the orderly (repetitive) effect which may mask the pickforce data. To analyze this effect, a vibration model of the cutting process is first developed. Subsequently, the vibration model is explored to (a) demonstrate that the orderly effect does no reduce the reliability of the pickforce data, and (b) suggest alternative means in improving the quality of pickforce records by modifying parameters of the cutting machine

Remnant roof coal thickness measurement with passive gamma ray instruments in coal mines

The need to leave coal on the roof of a mined-out area occurs on both continuous miner and longwall sections and is derived from considerations of ground control, quality control, machine guidance, or simply good operating practice. Efforts at measuring boundary coal thickness using the nucleonic method is described. Natural gamma devices are the instruments of choice, and the use of gamma-ray backscatter sensing is discussed. The calibration of natural gamma background (NGB) instruments is described, and it is concluded that they cannot be used in areas where NGB radiation is not present. This radiation is ordinarily present in the fine-grained sedimentary rocks that bound many coal seams. >

The Integrated Controls Platform

Factory automation can be defined by four basic technology elements; intelligence, motion control, sensors, and mechanisms. Historical controls design has seen engineers perform an integration role, combining various pieces of hardware, software, and interfaces into a system. The factory automation marketplace of the 1990 s is seeing a convergence of these technology elements which is requiring a new generation of controller, the Integrated Controls Platform, providing better functionality at reduced cost with reduced engineering and support effort. The functional requirements for design of an Integrated Controls Platform, including motion control, machine guidance vision, cell control, operator interface, and system software will described.

Real-time positioning of moving objects by dynamic target tracking

Positioning and navigation of construction machines are one aim in the Special Research Center on “High Precision Navigation”, an interdisciplinary project at the university of Stuttgart (FRG). The positioning is done by a system of several electronic cameras containing lateral effect photodiodes in the image planes. Two modes of measurement are described: With a minimum of two fixed cameras the positioning is possible in a limited working space. The elimination of reflections along with system calibration leads to a high accuracy in object space of at least 1 : 10000. As an example the dynamic survey of an industrial robot is presented. With electronic cameras mounted on a motorized theodolite the system works as a highly precise dynamci surveying robot for guidance of machines on construction sites. This system is a powerful dynamic measurement tool in competition with CCD-cameras-based systems and works already with small desktop computers.

Improving the User Guidance of Ticket Slot Machines

The user guidance of ticket slot machines has been improved by developing design principles for the front-plate. The work was carried out by collecting material of ticket machines all over FRG, by recordings of eye-movements, by analyzing of passenger1s-behaviour, and by experiments with a simulator. Field experiments and laboratory experiments showed, that a new panel with integrated push buttons in two dimensional matrix organisation is significantly better (minimizing time and errors) than the usual panels with undefined organisation, The new panel, basing on an operating sequence diagram, is installed at the Stuttgart transport association since January 1983.