Overhead Rail Research Articles

Design and Experimental Testing of an Overhead Rail Automatic Variable-Distance Targeted Spray System for Solar Greenhouses

Crop cultivation in solar greenhouses is affected by issues such as low levels of automation in spraying machinery, inefficient spraying, and a lack of suitable spraying equipment for vertically cultivated crops, all of which are in urgent need of resolution. To address these problems, this paper proposes a suspended-rail automatic variable-distance targeted spray system. The rated working speed of the spray system is 0.3 m/s, and the rated working pressure is 0.3 MPa. This system achieves precise spraying of crops at varying heights by dynamically adjusting the position of the spray nozzle. To ensure accuracy in spraying, the system employs a laser ranging sensor for real-time measurement of crop positions and spraying distances. Combined with a parameter processing scheme, the system generates control signals to adjust the operation of the electric push rod and electromagnetic valve, thereby dynamically adjusting the spraying distance and timing. Using vertically cultivated potted peppers as experimental subjects, this study compares the performance of fixed- and variable-distance spraying modes. The results indicate that, compared to the fixed-distance mode, the automatic variable-distance mode increases pesticide adherence by 16.65% and reduces pesticide usage by 29.58%. The proposed suspended-rail automatic variable-distance targeted spray system offers an effective technical solution for the precise spraying of vertically cultivated crops in solar greenhouses and thus contributes to improved pesticide utilization efficiency, reduced pesticide residue, and lower environmental pollution.

Analysis of in-service composite insulators used in overhead railway traction

Polymeric based Composite insulators are extensively used for overhead rail electric traction system; these insulators play an important role in the traction electrification which supply power to the locomotives of train. Traction insulators are subjected to a variety of stresses, like mechanical, electrical, environmental, etc., these stresses act in unison, degradation and subsequent failure of traction insulator influences the safety of traction power supply system. To understand the phenomena of degradation and in-service aging, experimental investigations are conducted on in service traction insulators to identify and analyze the structural changes occurred in the field for a specified time, the insulators are of composite silicone polymeric materials rated for 25 kV. The electrical performance on the insulator samples is investigated using leakage current analysis and surface resistance measurements under normal and fog/moisture conditions using a specifically designed fog test chamber. The structural changes are studied by using Scanning Electron Microscopy (SEM), Energy Dispersive X-Ray (EDAX), Fourier Transform Infra-Red (FTIR) and wettability measurements. The study highlights the in-depth analysis conducted on the performance of service insulators compares with the fresh, also suggests mitigation methods to overcome the probable failures in the field. Some interesting results obtained from the study are analyzed and presented.

Improvement and Simulation Analysis of a Swinging Toy Moving with Two Arms on an Inclined Overhead Rail

Improvement and Simulation Analysis of a Swinging Toy Moving with Two Arms on an Inclined Overhead Rail

Why Milk Consumption is the Bigger Problem: Ethical Implications and Deaths per Calorie Created of Milk Compared to Meat Production

Pictures of sides of beef, hanging from overhead rails in refrigerated warehouses and meat-processing plants, often leave a feeling of unease. These pictures provoke the notion that human beings have no right to inflict suffering and death on other sentient beings for the sole purpose of providing food. However, the ethical analysis conducted in this study shows that meat production, if animal welfare and deaths per calorie created are considered, is less of a pressing problem compared to the production of milk. While meat can be provided with minimal suffering to animals, the consumption of milk is always associated with considerable suffering during the dairy cow’s life-span and the lives of their offspring. Moreover, more bovine deaths per unit of calorific value created are associated with milk production compared to meat production. The vegan movement, which is currently growing, wishes to minimise farm animal suffering as much as possible. However, if a vegan diet is not possible, consumers should make an informed decision about the products they consume. Replacement of the calories obtained from meat with those from milk and dairy products is not rational if animal welfare is considered.

Development of a Swinging Toy Moving by Two Arms on an Inclined Overhead Rail

Development of a Swinging Toy Moving by Two Arms on an Inclined Overhead Rail

Dynamic Interaction between Manipulator and Omni-Directional Platform

Recent advancements in mechatronics has led to tremendous development of application of robots for industrial applications involving high health hazards, rough working conditions and difficult to reach locations. Robot assisted welding is one such high risk operation for human being. The industrial arc welding robots are either mounted on the floor, table or on overhead rails. In this scenario, the jobs to be welded are brought to shop floor. However, the on-sight joining of big pipes and structures with precision and speed, demands for mobility of welding robot. In this research work, a novel concept of mounting 5-dof welding robot on the omni-directional platform (Omni-WMR) is implemented to provides immense maneuvering mobility to the manipulator. This paper presents the combined dynamic model of omnidirectional mobile robot for welding operation to study the effect of dynamic interaction between manipulator and mobile platform. Dynamic interaction is carried out to find the variation in torque at manipulator link due to the motion of platform as well as its location on the platform. In addition, the variation in torque developed at platform wheels due to positioning the manipulator at two different locations on platform is accessed. For this, two case studies have been discussed to study the effect of dynamic interaction between manipulator and omni-directional platform.

A Centrifugal Contactor Design to Facilitate Remote Replacement

Advanced designs of nuclear fuel recycling and radioactive waste treatment plants are expected to include more ambitious goals for solvent extraction-based separations, including higher separation efficiency, high-level-waste minimization, and a greater focus on continuous processes to minimize cost and footprint. Therefore, annular centrifugal contactors (ACCs) are destined to play a more important role for such future processing schemes. Previous efforts defined and characterized the performance of commercial 5-cm, model V-02; and 12.5-cm, model V-05, single-stage ACCs in a nonradioactive environment. The next logical step, the design and initial evaluation of remote-capable, pilot-scale ACCs for use in a “hot” or radioactive environment has been completed. This work continues the development of remote designs for ACCs that can process the large throughputs needed for future nuclear fuel recycling and radioactive waste treatment plants. Novel designs were developed for the remote interconnection of contactor units, clean-in-place (CIP) and drain connections, and a new solids removal collection chamber. A three-stage, 12.5-cm-diam rotor module has been constructed and is being evaluated for use in highly radioactive environments. This prototype assembly employs three standard CINC V-05 CIP units modified for remote service and replacement via new methods of connection for solution inlets, outlets, drain, and CIP. Hydraulic testing and functional checks were successfully conducted, and then the prototype was evaluated for remote handling and maintenance. Removal and replacement of the center position V-05R contactor in the three-stage assembly was demonstrated using an overhead rail mounted PaR manipulator. Initial evaluation indicates a viable new design for interconnecting and cleaning individual stages while retaining the benefits of commercially reliable ACC equipment. Replacement of a single stage via remote manipulators and tools is estimated to take [approximately]30 min, perhaps fast enough to support a contactor change without loss of process steady-state equilibrium. The design presented in this work is scalable to commercial ACC models from V-05 to V-20 with total throughput rates ranging from 20 to 650 l/min.

ZeroG: Overground gait and balance training system

A new overground body-weight support system called ZeroG has been developed that allows patients with severe gait impairments to practice gait and balance activities in a safe, controlled manner. The unloading system is capable of providing up to 300 lb of static support and 150 lb of dynamic (or constant force) support using a custom-series elastic actuator. The unloading system is mounted to a driven trolley, which rides along an overhead rail. We evaluated the performance of ZeroG's unloading system, as well as the trolley tracking system, using benchtop and human-subject testing. Average root-mean-square and peak errors in unloading were 2.2 and 7.2 percent, respectively, over the range of forces tested while trolley tracking errors were less than 3 degrees, indicating the system was able to maintain its position above the subject. We believe training with ZeroG will allow patients to practice activities that are critical to achieving functional independence at home and in the community.

Steel Town (review)

Reviewed by: Steel Town Elizabeth Bush Winter, Jonah; Steel Town; illus. by Terry Widener. Atheneum, 2008. 40p ISBN 978-1-4169-4081-4 $16.99 R* 7-10 yrs Part informative treatise on the heyday of the American steel industry, part paean to blue-collar labor, Winter's poetic text traces the fiery journey of ore to iron to steel and celebrates the grinding, sweaty toil of the men who run it through the mill. The relentless heat and din of the 24/7 operation is captured in pulsing repetitions: "Inside the iron mill,/ it's like another world:/ fire and smoke,/ fire and smoke./ No matter the time of day or night,/ the men keep working,/ the machines don't stop:/ fire and smoke,/ fire and smoke." Everywhere there's danger—rivers of molten metal, train cars of bubbling ore that teeter on overhead rails, furnaces that measure degrees in thousands rather than hundreds. The lunchtime whistle heralds the only respite the workers will enjoy, from the time they climb down the stairs on Goat Hill Path at the beginning of the shift until "another shift is over./ Time to punch the time-card./ Time to get paid:/ Three crinkly bills/ in a grimy hand./ That means food." Widener's husky acrylic paintings turn the towering machines, furnaces, and smokestacks into smoldering monuments to industry, and the smoke-infused air grapples with the brilliant orange flames for the right to color the sky. He also takes just enough artistic liberty with scale and perspective to allow the workers to emerge as masters of the beast, trudging home beat but not quite beaten. Blast some Aaron Copland in the background and make this the centerpiece for a Labor Day program. Copyright © 2008 The Board of Trustees of the University of Illinois

Simulation model for the study of overhead rail current collector systems dynamics, focused on the design of a new conductor rail

Overhead rigid conductor arrangements for current collection for railway traction have some advantages compared to other, more conventional, energy supply systems. They are simple, robust and easily maintained, not to mention their flexibility as to the required height for installation, which makes them particularly suitable for use in subway infrastructures. Nevertheless, due to the increasing speeds of new vehicles running on modern subway lines, a more efficient design is required for this kind of system. In this paper, the authors present a dynamic analysis of overhead conductor rail systems focused on the design of a new conductor profile with a dynamic behaviour superior to that of the system currently in use. This means that either an increase in running speed can be attained, which at present does not exceed 110 km/h, or an increase in the distance between the rigid catenary supports with the ensuing saving in installation costs. This study has been carried out using simulation techniques. The ANSYS programme has been used for the finite element modelling and the SIMPACK programme for the elastic multibody systems analysis.

Microbiological quality of hygienically processed buffalo carcasses

Studies were conducted to assess the microbiological quality of buffalo carcasses processed hygienically in a modern abattoir as against those processed in traditional slaughter units of different sites. The hygienic measures followed include abattoir clean up operation, processing on overhead rail, careful removal of skin and viscera, closure of oesophagus and rectum and washing the carcasses with a spray of clean water. The carcasses, meat cuts and minced meat obtained from both the sources were examined for microbial load. A significant (P⩽0.001) difference in microbial load was seen in carcasses obtained from two sources, with carcass from traditional slaughter units showing 1.0–2.50 log higher microbial load. The reduction in microbial load in carcasses processed in a modern abattoir was attributed to the hygienic measures followed. The microbial load was high in shoulder portion and lower in leg portion and the data indicated that samples of shoulder, neck and rib surfaces provide a more realistic estimate of microbial load on buffalo carcasses. The meat cuts obtained from hygienically processed carcass had a shelf-life of six days as against three days for those obtained from traditional slaughter unit. The minced meat from hygienically prepared carcass had a shelf-life of four days as against one day for those obtained from local slaughter unit. The study indicated that by adopting proper hygienic and sanitary practices during processing of buffalo meat would yield meat with acceptable microbiological quality with extended shelf-life.

An ergonomic evaluation of three classes of material handling device (MHD)

The proliferation of material handling devices (MHDs) such as articulated arms and hoists is a direct result of the staggering increases in workers compensation claims attributed to repetitive lifting. In reducing the occurrence of repetitive lifting through MHD use, however, manufacturers have opened a Pandora's Box of other issues, ranging from the asymmetric nature of torso exertions common in MHD use to various job design and motor control issues. This study evaluates the effects of some critical job design parameters such as handled load and movement distance on the movement performance of three major classes of MHD. Ten young healthy male and female subjects used three different types of common MHDs with loads of 10 and 30 kg over distances of 0.6 and 1.8 m. Peak hand forces ranged from 50–80 N for the articulated arm and hoist with overhead rail MHDs, but reached 200 N with a fixed pivot hoist MHD. As a percent of each subjects' strength, peak hand forces generally tended to remain between 30 and 50%, except for the fixed pivot hoist when moving 30 kg over a 1.8 m distance. These conditions exceeded the strengths of 80% of the subjects. Peak velocities ranged from 0.8 to 1.2 m/s with the articulated arm and hoist when moving on an overhead rail, and from 0.8 to 1.6 m/s with the fixed pivot hoist. Subjects showed the fastest movement with the fixed pivot hoist, except with heavy loads. A distinct tradeoff between movement performance and biomechanical safety was discovered. In most cases, the MHD which showed the fastest movement also required the highest stresses. In general, implementation strategies should involve selection of the fastest MHD which does not exceed accepted limits of biomechanical stress. However more sophisticated limits for dynamic back stress must be developed and must reflect the various populations in the workforce. Relevance to industry The proliferation of MHDs in industry to replace repetitive lifting tasks has created a new source of potential musculoskeletal problems. This paper evaluates the comparative movement performance and ergonomic stresses of the three major classes of MHD in an effort to provide industry with some guidance for MHD implementation.

Bacteriological status of beef carcasses at a commercial abattoir before and after slaughterline improvements.

The bacteriological status of beef carcasses was monitored at a commercial abattoir before and after two stages of modernization to the beef slaughterline which included changing from cradle dressing to dressing on an overhead rail, and the introduction of hot water spray cleaning of carcasses. Although small significant (P less than 0.05) differences in bacterial count occurred among carcass sites within modernization stages, significant visit within stage variation and stage X site interactions prevented any significant change in overall count being observed among stages and carcass sites. Principal components analysis revealed small changes in the distribution of bacterial numbers on the sites sampled.

Paper B: A Public-Transport System Using Four-Passenger Self-Routing Cars

The proposed system is an automatic-taxi, public-transport service for towns and cities, capable of 10 000 passengers per hour per track and aimed to be competitive with the private car. Mini-sized cars are used which carry up to four adult passengers, using induction-motor drives powered from an overhead rail. The cars are driverless and route themselves at 35 mile/h to their destination with no stops at intermediate stations, though they are slowed down when changing to another line. The cars move along a light-weight totally-enclosed track of less than 7 ft diameter, which can be supported above existing roadways or buildings. The total capital cost is of the order of λ400,000 per single-track mile and the total operational cost 1 d. to 2 d. per passenger mile. A complete system for a town of 400 000 inhabitants, involving 100 single-track miles, would cost from λ30 million to λ40 million.

The Saskatchewan 1,000-curie cobalt 60 unit.

For the past year a 1,000-curie cobalt 60 unit (Fig. 1) has been in use in Saskatoon. The unit itself consists of a roughly spherical lead-filled steel casing 22 inches in diameter. Inside the casing is a wheel of heavy metal and lead, having at one point on its perimeter a cobalt source 1 inch in diameter and 1/2 inch thick. A tapered opening leads from the perimeter of the wheel through the lead to the exterior. When the cobalt is opposite this opening, a collimated beam escapes; when the wheel is rotated 180 degrees, the cobalt is shielded by 7 inches of “heavy metal” and the machine can then be considered as “turned off.” To turn it on, an electric clock is set to the desired exposure and a switch is turned. The wheel then rotates to the “on” position, and when it reaches this point the clock starts. When the required treatment time has elapsed, the wheel rotates back to the “off” position. A system of interlocks causes the wheel to rotate to the “off” position should the door of the room be opened during a treatment. The whole unit, which is suspended from overhead rails, has three movements—up and down, forward and backward, and vertical rotation. All of these movements are electrically driven and are controlled from a single small box containing six pushbuttons, which is suspended from the ceiling. By means of suitable treatment cones, various fields of 5 × 5 to 15 × 15 cm. can be obtained at 80 cm. source-skin distance. The length of each cone is either 20 cm. or 15 cm., so that ease in porting is assured. Larger fields can be obtained by increasing the source-skin distance. The final limiting diaphragm is located 15 cm. from the skin, so that the surface dose due to secondary electrons is virtually eliminated. The output is approximately 30 r per minute at this distance. Since cobalt 60 has a half-life of 5.3 years, the output falls 1.1 per cent per month. Calibration charts are prepared for each month and are made to be correct in the middle of the month. At the first of the month the output is larger by 0.5 per cent and at the end too small by 0.5 per cent. The unit is mounted with a universal fixture which allows for the simple fitting of a pin and arc director, a back-pointer for beam direction, and an apparatus for measuring and controlling compression of a patient. Set into the floor is a circular platform 8 feet in diameter, which can be made to turn at varying speeds, by an electric motor, so that rotational therapy can be employed. The problem of protection is similar to that with a 3-mev x-ray machine. The walls of the treatment room consist of 1 foot of concrete, which affords adequate protection from scatter, with an observation window containing 8 inches of plate glass. The room beneath is used for storage, and interlocking warning lights prevent anyone entering it when the machine is in use. There are no floors above the treatment room. The beam at all times is directed either toward the floor or the outside wall.