Operator Cab Research Articles

A real-time augmented reality system to see through forklift components

Limited visibility during the operation of forklifts is one of the most significant sources of danger in in-plant material handling. Existing systems record concealed areas via cameras and display them directly on monitors in the operator's cab. The operator has to temporarily turn his attention to a screen and is unable to perceive the real information necessary for the driving task. We developed the first augmented reality based driver assistance system for safety improvement in intralogistics. The results show the capability to eliminate view restrictions directly in the operator's field of view and create the illusion of transparent vehicle components.

О неэффективности нагнетательного способа проветривания при решении задачи нормализации пылевой обстановки в тупиковом забое калийного рудника

When potash ore is mined, a large amount of the harmful impurities, including dust, are released into the mine environment. Although potash dust is not toxic, at constant high concentrations it adversely affects the miner health. Hygroscopic properties of rocks in the potash mines do not allow the use of water to control dust. Ventilation approaches to the normalization of the dust environment also do not give positive results. Forced method of the ventilation of the dead-end mine workings used in all the mines in Russia is distinguished by the long-range air jet from the ventilation stack. This allows to create intensive vortex formation in the bottomhole part of the mine working for avoiding the occurrence of stagnant zones. However, during forced ventilation, a large vortex occurs. Results of studying the dynamics of dusty air streams in the space of a dead-end tunneling and cleaning working are presented in the article. In the mining face, there are two main sources of dust formation: the working face, where the rock mass is destroyed, and the bunker-loader, where the broken ore is poured. Both the first and second sources are identical in terms of dust formation power. The vortex formed during the forced ventilation method returns to the combine operator cab through the ore pouring area into the bunker. As a result, the composition of the atmosphere in the bottom hole significantly deteriorates. The greater the amount of air supplied during the forced ventilation method, the greater the dustiness of the bottomhole part of the mine. Conducted studies allow to conclude that the injection method of the ventilation of dead-end combine workings of the potash mines is ineffective to normalize the dust environment.

Wirtualne prototypowanie kolejki podwieszonej w aspekcie zwiększenia jej dopuszczalnej prędkości jazdy w kopalniach węgla kamiennego

Due to the longer distance of moving the crew to the workplace in hard coal mines, the possibility of increasing the maximum permissible speed of suspended monorails was considered. To ensure an adequate level of safety, decelerations affecting the crew in the case of emergency braking in various travelling conditions were analysed. The computational model was verified based on the results of the bench tests on a dedicated test track. The article presents a comparison of results of numerical calculations with measurements at the test stand, and results of numerical simulations in relation to the criterial states that could not be checked at the test stand as well as the analysis of overloads that affect the crew during the emergency braking. These overloads have a significant impact on safety of the operator and passengers, and their determination and analysis may be the basis for assessing the degree of safety as well as for the development of guidelines for designing the additional equipment for the operator's cabs and passenger cars, i.e. components increasing their safety

Analysis of unrestrained crawler-crane counterweights during tip-over accidents

Crawler crane designers continually extend the height of the machines. Models that reach over 500 feet high are commercially available. Of course, as the crane height increases, so do the hazards associated with tip-over accidents. Destabilizing tip-over moments are generated by the boom and the suspended payload when they extend beyond the base of support. Stabilizing moments are generated by the crane base and counterweights. Counterweights are normally secured by mechanical fasteners such as pins, bolts, or chains. However, some cranes use unrestrained counterweights that are held in place only with friction. This paper investigates the dynamic behavior of such unrestrained counterweights during tip-over accidents. The analysis shows that counterweight blocks can break free and slide off the crane when the tip angle is as small as 20 degrees. Scale-model testing of cranes with unsecured counterweights demonstrates that the fall path of the spilling counterweights on certain crane models intersects the operator cab and thus presents a deadly hazard.

INCREASING THE PRODUCTIVITY OF THE BRIDGE CRANE DUE TO THE INTRODUCTION OF ARDUINO'S HARDWARE AND SOFTWARE BASE IN ITS CONTROL SYSTEM

The research results of the possibility of increasing the productivity of the bridge crane through the introduction of hardware and software base Arduino in its control system are given in the article. The indexes of technical productivity of batch operation lift and carry machines of periodic action are analyzed and the working cycle duration has been shortened. Several cases (successive execution –- each subsequent movement only begins after the end of the previous one; partial combination – combine only a few separate movements are combined; full alignment – all crane movements with the load are combined in time) is considered. In this article, based on the results of the analysis, the control of the load-lifting machine was built due to of the introduction of telecommunication systems and technologies, namely the use of microcontrollers with the implementation of control using wired (Ethernet) or wireless (Bluetooth, Wi-Fi) network. Because there is the need to increase the productivity of lift and carry machines, to improve the working conditions of personnel, to improve the reliability and durability of machine elements, causes the creation of new, more advanced systems of machine management and partial or complete automation of their work. Safety in the production will increase significantly with this technology, as it will be possible to implement protection against overload, excess speed, rocking, moving cargo to areas where people are located and so on the results of the article are shown. Crane management can be done either from the operator's cab, directly controlled by the controller, or remotely, by transmitting signals over wired (Ethernet) or wireless (Bluetooth, Wi-Fi) networks.

The Use of Noise Dampening Mats to Reduce Heavy-Equipment Noise Exposures in Construction.

The performance of sound barriers was evaluated to determine their technical effectiveness and practicality in reducing noise exposures to operating engineers in construction. Commercially purchased sound dampening mats (SDMats) were installed inside three heavy-equipment engine compartments. Sound pressure levels (SPLs) were measured before and after installing the SDMats while the equipment was on idle and full-throttle settings where it normally operates. SPLs inside the heavy-equipment operator cabs were significantly reduced by 5.6–7.6 dBA on the full-throttle setting following installation of the SDMats (p < 0.01). The evaluated engineering control intervention was simple to install, affordable, and substantially reduced the engine noise reaching the heavy-equipment operator, potentially reducing reliance on hearing-protection devices to protect construction workers from noise exposures.

Identification of the Types of Measured Acoustic Modes Inside the Operator's Cab in a Bulldozer

Abstract The aim of the study was to identify acoustic and structural modes in the spectrum obtained exper-imentally inside an operator's cab in a bulldozer. Measurements were taken inside the operator's cab in a caterpillar-track bulldozer Polremaco TD12NPH2E-2000, designed for work in underground mine enclosures. The acoustic pressure spectrum was obtained for varied rotational speeds of the engine during the free run of the machine. The reverberation time of the cab was determined basing on the pulse-type excited pressure response, followed by identification of the spectral components registered by measurements. Thus, identified frequencies were compared with natural acoustic frequencies registered inside the operator's cab and with frequencies associated with the valves and ignition frequencies due to rotational speed and natural frequencies of structural vibrations of the cab's walls. This study was conducted in an attempt to reduce the noise inside the operator's cab using passive methods

A Practical Real-Time Motion Cueing Algorithm for Crane Simulator

This paper addresses motion simulation issues involved in a crane simulator with a 6-Degree-Of-Freedom platform. The crane dynamical models in terms of a range of motion equations are built for the operator cab in various main operating conditions. The ways to make the motion to be reproduced are investigated and the corresponding real-time motion cueing algorithm is proposed based on a special curve-merging approach. The algorithm is of simplified form and the needed computing time is very short, which makes it very practicable. The crane simulation system with this algorithm being adopted has been successfully developed and put into practice. The field application showed that the algorithm is able to ensure achievement of satisfied motion cueing effects. The proposed motion simulation models and the corresponding algorithm will provide significant reference value for developing similar motion simulation systems for all types of large-scale cranes or construction machinery.

The Evaluation of Bitumen Fume Capture Efficiency for Road Pavers

INRS has evaluated the performance of fume extraction systems on road pavement asphalt pavers over a two year period between 2009 and 2011. These systems are used to reduce operator exposure by capturing fumes at the auger, where most emissions are generated, and discharging them above the paver at sufficient velocity to prevent fumes blowing back towards the operator cab. Evaluation was conducted using a tracer gas (SF6), based on the NIOSH-proposed protocol (1997). Initial tests revealed the limits of this methodology, which included adverse effects on measurement resulting from the paver being located in a test hall; panelling installed to isolate the machine from draughts seriously distorted the flow field. Further tracer gas tests conducted outside, under conditions more representative of real operation, showed that the fume capture system must be integrated into the machine design. Special attention should be given when implementing various cooling systems (diesel engine, hydraulic compressor) since air draughts from these, if improperly directed, may greatly degrade fume capture efficiency.

A Perception-Based Method for the Noise Control of Construction Machines

Abstract During operation, construction machines generate high noise levels which can adversely affect the health and the job performance of operators. The noise control techniques currently applied to reduce the noise transmitted into the operator cab are all based on the decrease of the sound pressure level. Merely reducing this noise parameter may be suitable for the compliance with the legislative requirements but, unfortunately, it is not sufficient to improve the subjective human response to noise. The absolute necessity to guarantee comfortable and safe conditions for workers, requires a change of perspective and the identification of different noise control criteria able to combine the reduction of noise levels with that of psychophysical descriptors representing those noise attributes related to the subjective acoustical discomfort. This paper presents the results of a study concerning the “customization” of a methodology based on Sound Quality for the noise control of construction machines. The purpose is to define new hearing-related criteria for the noise control able to guarantee not only reduced noise levels at the operator position but also a reduced annoyance perception.

Case study analysis of construction excavator H&amp;S overturn incidents

PurposeConstruction plant and equipment harbour significant health and safety hazards. One particular item, the mini‐excavator, presents a hazard from its inherent instability and tendency to overturn during use. The purpose of this paper is to investigate turnover incidents to observe prominent factors and contribute to development of best practice guidance for improving health and safety relating to mini‐excavator use.Design/methodology/approachComprehensive documentary data from eight case study incidents, along with anecdotal data from a further three, were qualitatively analysed in terms of: machine weight, machine activity, ground type/topography, operator competence, type of overturn, damage to property, and injury to person(s). Results were presented to experts in the field for comment and conclusions/recommendations accordingly developed.FindingsObserved prominent casual factors include: inadequate assessment of risk and non‐adherence to safe working practice, working on poor ground, and working on inclined surfaces. The use of sealed operator cabs and proprietary seat restraint mechanisms seem to mitigate risk of personal injury to operators during overturn incidents. A need for cyclic training to reiterate good operator and banksman practice is emphasised, while construction managers should also be aware of the risks, and help implement risk controls.Research limitations/implicationsFindings will inform construction plant management research generally, and the subject of mechanised workplace transport stability specifically.Practical implicationsBest practice protocol will inform health and safety management of mini‐excavators at the workplace.Originality/valueAcademic research into mini‐excavator stability is embryonic; this paper furthers evolving knowledge in the field.

Design and Evaluation of a Suspension Seat to Reduce Vibration Exposure of Subway Operators: A Case Study

Subway operators have complained about discomfort caused by whole-body vibration. To address this problem, a suspension seat with extensive ergonomic features has been adapted to the confined space of the subway operator cab. The suspension was modified from an existing suspension in order to reduce the dominant frequency of the subway vertical vibration (2.4 Hz). The suspension seat has been extensively tested on a vertical hydraulic shaker. These tests have shown that the SEAT value was lower for a higher vibration level, for higher subject weight, and for the suspension adjusted at median height. The seat also produces a lower SEAT value when there was a predominance of the 6 Hz vibration component. The horizontal seat adjustments had no influence on the suspension SEAT value. Removing the suspension damper also decreases the SEAT value for all the tested configurations. The final version of the suspension seat prototype was validated during normal subway operation with 19 different operators having weight in the 5th, 50th and 95th percentile of the operator population. Accelerations were measured with triaxial accelerometers at the seat cushion, above the suspension and on the floor. In addition to the vibration measurements, each operator was asked about his perceived discomfort from vibration exposure. Globally, the suspension seat attenuated the vertical vibration (SEAT values from 0.86 to 0.99), but discomfort due to amplification of the 2.4 Hz component occurred when the suspension height was adjusted at the minimum, even when the global weighted acceleration was lower (SEAT value < 1). These results suggest that in order to reduce the discomfort caused by whole-body vibration, the transmissibility of the seat should also be considered, in particular when there is a dominant frequency in the vibration spectra.

Noise controls for drills in the dimension stone industry

Drills in the dimension stone industry have proven to be a problem when it comes to overexposures to noise. These drills include, but are not limited to slot drills, down-hole drills, and horizontal lift-hole drills. Although drills with acoustically treated operator cabs exist for this industry, most drills encountered do not have them. Considerable effort has been made by both the Mine Safety and Health Administration (MSHA) and industry to achieve compliance with the noise standards stated in Code of Federal Regulations (CFR) Title 30, part 62 for the drills without operator cabs. Several individual noise controls are available for these drills. They include exhaust mufflers, operator control barriers, hammer covers, face shields, and three-sided enclosures. A joint noise study was conducted by MSHA and a cooperative mining company to determine the effectiveness of these individual noise controls alone and in various combinations. Previously, these noise controls were studied separately under varying conditions and some found to provide significant noise reductions. The study was conducted to determine their effectiveness under the same conditions and to quantify not only their reduction in sound level, but also overall noise dose.

Field assessment of control techniques and long-term dust variability for surface coal mine rock drills and bulldozers

ABSTRACT Airborne respirable dust surveys were conducted at six surface coal mines to investigate the effectiveness of dust control methods used on rotary rock drills and bulldozers. Dust controls commonly used on drills include a dry dust collection system, exhausting from a shrouded area around the collared hole, and an enclosed drill operator cab, filtering airborne dust from the cab. Bulldozers are also typically equipped with an enclosed operator cab as a dust control measure. Airborne respirable dust sampling was conducted near each equipment's source of generation and inside its enclosed cab. Silica analysis was performed on the dust samples to determine the percent silica content in the dust generated at the six mining operations. An additional eight-month follow-up of dust sampling was also conducted in the enclosed operator cabs of several rock drills and bulldozers. Data were analyzed for long-term variability of accepted control methods to abate dust and silica levels. The highwall rock drill was the major and most variable dust source as compared to the bulldozer, generating dust levels, on average, one order of magnitude higher than dust levels of the bulldozer. Four of the six drills surveyed had dust containment and capture problems at the shrouded drill table above the hole. Repairs or modifications to three of the drill dust collection systems were shown to reduce dust levels by more that 50% next to the shrouded drill table. The enclosed operator cabs provided more than 90percnt; and more than 40% lower dust levels than at the dust source for the drill and bulldozer, respectively. Long-term sampling of several of these highwall drills and bulldozers showed that the dust levels in the drill cabs were frequently higher than 0.2 mg/m3 and more variable than in the bulldozers. The bulldozer dust levels were frequently below 0.2 mg/m3. Future research should focus on improving some of the deficiencies present in the drill/s primary dust collection system, and developing quality control methods to ensure the integrity of enclosed cab protection for equipment operators.

Ergonomics of grab unloaders for bulk materials handling

An ergonomic study of operator cabs for grab unloaders is presented herein. Our results demonstrated that the drivers adopted poor postures, partially owing to the basic geometry of the situation and partially because they used only the central lower front window for downward vision and control boxes obstructed vision. These problems have been exacerbated by introducing extremely large bulk carriers that have a wider hold than the previous ships used. Relevance to industry This study evaluated the workplace and workspace design of a cab of grab unloaders for bulk materials handling from an ergonomics perspective. Recommendations for improvements are also presented.

The Anthropometry of Forest Machine Operators in the Southern USA

Anthropometric dimensions critical to the design of operator workspaces and cab access in grapple skidders were collected from a sample of Southern United States loggers. The data were then compared to existing SAE and ILO anthropometric recommendations and data. Results indicated that southern grapple skidder operators are generally taller in stature, sitting height and seated eye height than the worldwide population measured to determine the SAE and ILO guides. Southern operators are also heavier than subjects measured for the SAE recommendations.

Design of an active suspension for a heavy duty truck using optimal control theory

The optimal active suspension for the cab in a tractor-semitrailer vehicle model is obtained using the linear stochastic optimal control theory. Two state controllers, full state and limited state feedback, are determined. The control law minimizes a performance function representing operator discomfort and cab suspension travel. The randomly profiled road is modelled as a filtered white noise excitation and time delays due to the multiaxle excitation inputs are included. The performance of the optimally active controlled system is compared with the performance of an optimal passive system.

Safety and ergonomics in the maintenance of heavy forest machinery

Occupational accidents and ergonomic problems in the maintenance (i.e. the servicing and repairing) of heavy forest machinery are investigated on the basis of the literature, accident reports, interviews, and observations. Heavy forest machinery includes those machines used in logging operations—forwarders, processors, harvesters, and agricultural tractors equipped for forest work. The machinery is maintained by the operators mainly in the forest. The main problems in the work environment are caused by: cold in winter; the necessity of working barehanded; the handling of oil or solvents; the risk of slipping and falling associated with climbing up to and working on machines; troublesome working postures; the temporary need for great strength in handling heavy machine parts. The accident rate of maintenance work is high compared to the one of operating machines—nearly as high as in logging work with chain saws. The prevention of health hazards and accidents related to maintenance work is a difficult but essential question. The improved work conditions in the operator's cabs of the machinery have not, of course, improved the work conditions in the maintenance carried out mainly outdoors.

A Monitor for Crop Moisture and Combine Cylinder Speeds

ABSTRACT THE electronic circuitry to display the moisture con-tent and optimal combine cylinder speed for varying moisture contents has been designed and tested. It can be operated from inside the operator's cab and uses the combine's electrical system for power. The system has an accuracy of 1 percent moisture or 30 rpm and is compati-ble with the adjustment capabilities of the combine.

From the window of the steel-ladle-car operator's cab (in competition)

From the window of the steel-ladle-car operator's cab (in competition)