Crawler Tracks Research Articles

Intelligent Assisted Travel Wheelchair Based on Image Recognition Technology

This paper introduces an intelligent image recognition system integrated into a wheelchair based on deep learning in cold environments, aiming to improve the convenience and safety of disabled individuals. The system adopts advanced image recognition technology to monitor road conditions in real-time through the camera and to detect and measure distance to foreign objects on the road. The system visualizes the detection results on the wheelchair screen to assist the user in avoiding and improving the safety of their daily travel. In addition, the system also includes crawler tracks, seat heating, snow and rain protection, and other functions. The wheelchair has a wide range of application prospects and development potential. It is expected to be widely used in the future, providing a strong guarantee for the safe travel of disabled individuals in China.

Automatic Stair Climbing Trolley

Abstract: A step climber is fundamentally a streetcar which is being utilized to convey the heap or baggage, so that moving turns out to be a lot more straightforward through steps and labor is decreased successfully. Additionally, it is broadly utilized in ventures and assembling plants where lift or lifts frameworks are not accessible, so that stacking or dumping of material becomes more straightforward and furthermore builds the general consumer loyalty and market prerequisites to which the business is trading or bringing in. Likewise Step climbing streetcar chiefly comprises of 2 kinds either physically worked (TriStar Wheel Streetcar) or it tends to be driven consequently utilizing battery and mechanized track framework. For our situation it is completely computerized and just the administrator needs to provide a guidance utilizing the handle and the streetcar will be pushed or pulled up or down strides on a flight of stairs. It depends on rack and pinion component in which the alternating movement of pulley or stuff is sent to a straight responding movement. Additionally, the stuff box mechanized framework is utilized to diminish the stuff proportion and subsequently to build the precise speed of the associated shaft. Alongside that polymer crawler tracks are being utilized which will be at the foundation of the streetcar to give an excellent hold and contact with the surface which is the main piece of the streetcar to choose its movement over the steps

Selecting pre-tensioning of rubber reinforced track on agricultural tractor with cushion suspension

Rubber reinforced tracks and cushion suspension are becoming increasingly common on agricultural tractors. They increase environmental friendliness, provide asphalt driving ability and allow for higher transport speed of crawler tractors, improving working conditions for the tractor driver. The crawler tracks of these thrusters have a high degree of suppleness, so a loss of stability of the rubber reinforced track on the drive wheel can be a problem when operating under high traction loads. The most effective measure to increase the stability of the rim in the mover is to increase the pre-static tension. However, high track tension increases losses in the undercarriage and stresses the undercarriage, resulting in reduced undercarriage life and loss of performance. Analytical dependencies are derived to determine the rational pre-static tension of rubber reinforced crawler tractors with cushion and blocked suspensions during start of moving and moving modes. The required static pre-tensioning of rubber reinforced tracks for Belarus 1802, 2102 and 2103 tractors is determined. It has been found that the greatest necessary static pre-tensioning of the rubber reinforced tracks is required at the maximum forces on the driving wheels of the tractor. It is shown that locking the suspension when operating the tractor with high traction loads at low speed allows to reduce the required static pre-tensioning of rubber reinforced tracks and, as a consequence, their loading. The results of this research can be used in design and operation of tractors with rubber reinforced tracks.

Designing and Manufacturing of Automatic Robotic Lawn Mower

This study is about the manufacturing of a personified automatic robotic lawn mower with image recognition. The system structure is that the platform above the crawler tracks is combined with the lawn mower, steering motor, slide rail, and webcam to achieve the purpose of personification. Crawler tracks with a strong grip and good ability to adapt to terrain are selected as a moving vehicle to simulate human feet. In addition, a lawn mower mechanism is designed to simulate the left and right swing of human mowing to promote efficiency and innovation, and then human eyes are replaced by Webcam to identify obstacles. A human-machine interface is added so that through the mobile phone remote operation, users can choose a slow mode, inching mode, and obstacle avoidance mode on the human-machine interface. When the length of both sides of the rectangular area is input to the program, the automatic robotic lawn mower will complete the instruction according to the specified path. The chip of a Digital Signal Processor (DSP) TMS320F2808 is used as the core controller, and Raspberry Pi is used as image recognition and human-machine interface design. This robot can reduce labor costs and improve the efficiency of mowing by remote control. In addition to the use as an automatic mower on farms, this study concept can also be used in the lawn maintenance of golf courses and school playgrounds.

GROUND LOADING BY TRACKS OF TRACK MACHINES: REVIEW OF DESIGN SCHEMES

The results of investigations in the field of existing soil loading schemes by tracks of tracked vehicles and their effect on the traction force realized by a caterpillar propulsion device are presented. The review shows that most researchers emphasize the important role of lugs in the creation of tractive effort. However, most of the existing methods of calculating the traction force on the clutch are based on one or another specific design scheme that does not depend on the loads acting on the tracks, on the combination of the parameters of the grousers and on the physical and mechanical properties of the soil. The use of these methods does not allow us to consider the sequence and alternative variants of soil disruption, and also to establish a relationship between the magnitude of the tangential force acting on the tract with a wide range of combinations of geometric parameters of the grousers, and to link it to the physical processes taking place in the soil. Consequently, these methods do not fully describe the interaction of the crawler tracks with the ground, which makes it difficult to use them to optimize the geometric parameters of the lugs. The authors proposed an analytical method for analyzing the interaction of soil with a track of a caterpillar engine based on the regularities of the theory of the limiting state of ground masses and the main provisions used in the theory of cutting soil, taking into account the revealed features of this interaction, which makes it possible to investigate the interaction of tracks of a caterpillar propulsion with soil, taking into account the multiphase and alternative options for the destruction of soil between the grousers. This method allows you to choose the parameters of the lugs, providing an improvement in traction and coupling properties of crawler tractors.

Rigid multi-body kinematics of shovel crawler-formation interactions

Large capacity shovels are deployed in surface mining operations for achieving economic bulk production targets. These shovels use crawler tracks for effective terrain engagement in these environments. Shovel reliability, maintainability, availability and efficiency depend on the service life of the crawler tracks. In rugged and challenging terrains, crawler wear, tear, cracks and failure are extensive resulting in prolonged downtimes with severe economic implications. In particular, crawler shoe wear, tear, cracks and fatigue failures can be expensive in terms of maintenance costs and production losses. No fundamental research has been undertaken to understand the crawler-formation interactions in challenging and rugged terrains in surface mining operations. This study forms the foundations for providing long-term solutions to crawler failure problems. The kinematic equations governing the crawler-formation interactions have been formulated to characterise the crawler motions during shovel production. These equations capture the motions governing the link pin joint, oil sand terrain joint and driving constraints based on the multi-body rigid theory. Crawler propel is achieved by using prescribed velocities along a translational degree of freedom (DOF) and a translational and rotational DOF. The crawler kinematic solutions show that the 3-D crawler–terrain model results in 132 DOFs and requires dynamic modelling to obtain the unknown degrees of freedom. A 3-D virtual prototype model is built to capture the crawler-formation interaction in MSC ADAMS based on the rigid body crawler kinematics. The virtual prototype simulator is supplied with mass properties of crawler shoe, mass, stiffness and damping characteristics of oil sand and external loads due to machine weight and contact forces to obtain the time variation of position, velocity and acceleration for the crawler–terrain engagement for given driving constraints. The results from the driving constraints yield a non-linear longitudinal motion of the crawler track assembly. The crawler track lateral and vertical displacements during translation-only motion fluctuates with maximum magnitudes of 0.7 and 3.6 cm. Similarly the fluctuating longitudinal, lateral and vertical velocities and accelerations have maximum magnitudes of 0.22, 0.046 and 0.56 m/s and 7.41, 1.73, and 34.9 m/s2, respectively. This research provides a strong foundation for further study on developing flexible crawler track model for predicting crawler shoes dynamic stress distributions, cracks development and propagation and fatigue analysis during shovel operations.

Characterization and System Identification of an Unmanned Amphibious Tracked Vehicle

Experimental testing of an unmanned amphibious tracked vehicle on dry sand, in the surfzone and in water, has been performed to explore its maneuvering and performance characteristics for the planned future development of an automatic control system. The 2.69-m-long, 295-kg concept vehicle utilizes a small waterplane area twin hull (SWATH) configuration with integrated crawler tracks and twin propellers for propulsion. Maximum traversable incline tests on dry sand reveal that the vehicle has a drawbar pull (DP) of about 1000 N (about one third of its weight) and can operate on slopes of 15 ° briefly and 10 ° for extended periods of time. Maneuvering tests were performed on flat, dry sand, as well as into and out of a surfzone at a beach site with inclines ranging from about 3 ° to 6 ° . In each of the tests, the track forces, speed over ground, and both linear and rotational accelerations were measured. Also recorded were environmental conditions, such as wind speed, significant waveheight/period, and ground slope. The tests reveal that the vehicle has a maximum straight-line flat ground speed of about 2 m/s, a minimum flat ground turning radius of 2.4 m, an in-water minimum turning radius of 1.9 m, and a maximum straight-line waterborne speed of 1.2 m/s. It is also shown that system identification applied to the data recorded from the flat ground and waterborne maneuvering tests can be used to find a linear, parametric state-space model for the vehicle that adequately reproduces its motion. Land-to-sea transition tests in two different seas of one-third significant waveheights of 8 and 28 cm (both measured at a distance of 6 m from the mean waterline on the beach) show that the vehicle exhibits substantial track slip as it traverses into the surfzone and its weight becomes increasingly supported by the displacement of its hulls. The tractive force model developed by Wong (Theory of Ground Vehicles, New York, NY, USA: Wiley, 2001) is modified to account for the reduction in track-supported vehicle weight as the vehicle becomes waterborne. It is shown that this adapted model captures the main physical features of the measured track forces. The waveheights and periods recorded during surfzone transition tests are used to examine the seakeeping properties of the vehicle. It is found that the vehicle's natural frequency of roll is near the dominant wave frequencies measured. A Froude-Krylov strip theory simulation shows that the wave forces acting on the vehicle in 28-cm waves may be slightly larger than the force measured on each track when the DUKW-Ling is crossing the transition zone between the beach and surfzone and should not be ignored in modeling and simulation studies.

Investigation of the Stress-Strain state of Rubber-Reinforced Crawler Tracks by the Finite Element Method. Part 2. Results

Investigation of the Stress-Strain state of Rubber-Reinforced Crawler Tracks by the Finite Element Method. Part 2. Results

Investigation of the Stress-Strain state of Rubber-Reinforced Crawler Tracks by the Finite Element Method. Part 1. description of Design and Modelling

Investigation of the Stress-Strain state of Rubber-Reinforced Crawler Tracks by the Finite Element Method. Part 1. description of Design and Modelling

Influence of residual stresses on the precision of crawler tracks’ hollow fingers under high-temperature thermomechanical treatment with deformation by screw cogging

Residual stresses formed under screw cogging deformation in the high-temperature thermomechanical treatment mode were considered. They facilitate the increase of hot-rolled metal pipe precision up to precision level of cold-calibrated rolled metal by outside diameter.

Interactive and Dynamic Integrated Module for Mobile Cranes Supporting System Design

Analyzing and designing a crane supporting system can be time-consuming process. In particular, the dynamic nature of mobile crane operations entails a variety of reaction values for truck and crawler cranes. The platform of a mobile crane can either be set on outriggers—denoted as a truck crane, or on a crawler tracks—denoted as a crawler crane. Designing of a mobile crane supporting system depends on the lifting configuration, type of crane and the type of materials to be used under the crane outriggers or crawler tracks. This paper presents an automated system which is designed to assist practitioners in calculating the mobile crane’s support reactions and in designing the supporting system. This system is developed such that it can generate a 2D reaction influence chart which shows the reactions for each outrigger at varying horizontal swing angles and vertical boom angles to the ground. Most of the geometric configurations needed to perform the support design are not ordinarily given in crane manufacturer’s manual and to address this deficiency, this newly developed system has been integrated with a previously developed crane database which contains information on widely used mobile cranes for construction along with a crane selection system. A case example is described in order to demonstrate the use and effectiveness of the presented system in automating crane lift analysis.

Development of “Souryu‐IV” and “Souryu‐V:” Serially connected crawler vehicles for in‐rubble searching operations

AbstractThe authors have developed Souryu‐I, Souryu‐II and Souryu‐III, connected crawler vehicles that can travel in rubble. These machines were developed for the purpose of finding survivors trapped inside collapsed buildings. However, when conducting experiments in post‐disaster environments with Souryu‐III, mechanical and control limitations have been identified. This led the authors to develop novel crawler units using crawler tracks strengthened with metal, and develop two improved models, called Souryu‐IV (composed of three double‐sided crawler bodies, a joint driving unit, a blade‐spring joint mechanism, and cameras) and Souryu‐V (composed of mono‐tread‐crawler bodies, elastic‐rod‐joint mechanisms, and cameras). The authors then conducted basic motion experiments and teleoperated control experiments on off‐road fields with Souryu‐IV and Souryu‐V. Their high performance in experiments of urban rescue operations was confirmed. However, several problems were identified during the driving experiments, and are reported in this paper, as well as a few possible solutions to solve them. This paper describes Souryu‐IV and Souryu‐V, their mechanisms, their cameras, and the experiments to test their mobile performance. © 2008 Wiley Periodicals, Inc.

Adverse effects of simulated harvesting of short-rotation willow and poplar coppice on vertical pressures and rut depths

Little is known of the effects of mechanized harvesting on ground conditions during the harvesting of short-rotation coppice. An investigation was therefore carried out in which different vehicles were used to simulate the effects of wheeling from heavy and light harvesters and crop removal equipment. The experiments were carried out on sites containing Bowles hybrid willow ( Salix viminalis) and poplars ( Populas rap) and on clay and sandy loam soils. The effect of different vehicles was assessed in terms of rut damage and direct measurements of soil stress using buried sensors. Maximum stresses measured 0.3 m below tractor wheels ranged from 50 to 200 kPa, but the greatest stresses, 350 kPa, were recorded under laden trailer wheels. Maximum stresses measured beneath crawler tracks were only 25 kPa. Similarly, substantial ruts were caused by vehicles simulating wheeled harvesters, the deepest ruts were caused by laden trailers but crawler tracks created least disturbance. Wheeling was carried out at soil water contents above the plastic limit and the deepest ruts were created on clay rather than sandy loam soil. The effects of the stresses generated in the soil could impede future root growth, and the deeper ruts formed could damage existing root systems of coppice.

The Healing Hand

This article focuses on engineers who are making unique contributions behind the headlines of the World Trade Center disaster. To do the job, engineers at the site had been using technology created by distant colleagues. Excavators, specialized vehicles, and robots are navigating the area, and teams of workers and technologists are slowly removing the concrete and steel shards of the fallen buildings. Robots moved on crawler tracks to carry video and infrared cameras into the ruins. Some worked at the ends of tethers as they dragged power and communications links behind them. High-flashpoint fuels are being discussed as a way of mitigating the damage if all else fails. Additives, for instance, could preclude violent explosions, but they are also likely to make the fuels less efficient. There are also highly sensitive sensors that can detect minute quantities of substances such as explosives, and improved 3D luggage-screening technologies to help airport personnel interpret what they see.

A gantry crane system for handling outdoor container- grown nursery stock

This paper describes an experimental gantry crane system for handling hardy ornamental nursery stock to and from outdoor standing out beds. The battery electric-powered machine has an 8 m span and runs on lightweight rubber crawler tracks, thus avoiding the need for special ground preparation. Containers are transferred from trailers running on roads parallel to the beds in 1 × 1·2 m pallets which can be picked up using a simple hoist. The basic manually controlled experimental gantry increases workrate by 27% compared with manual handling. The implementation of electro-mechanical automatic guidance and a computer control system improves workrate to at least double that achieved by manual handling. Further improvements in workrate can be gained by increasing the size of the pallets.

Leader cable guidance of an experimental field gantry

A leader cable guidance system for a 9 m span experimental gantry running on crawler tracks has been designed and evaluated, both theoretically and practically. The system is described and the theory behind the control of this machine explained. Field trials have shown that the path of the experimental gantry is consistent over repeated passes under automatic control to ±60 mm. These results confirm the predictions of a computer model which shows that further improvements could be made at modest cost. The use of straight line automatic guidance and control of a commercial field gantry is discussed and economic aspects considered. It is concluded that such a system can be economically viable for intensive field vegetable production.

The development of a nine metre span gantry for the mechanized production and harvesting of cauliflowers and other field vegetables

A wide span self propelled gantry running on crawler tracks was designed and constructed for the mechanized production and harvesting of vegetable and salad crops such as cauliflowers, cabbages and lettuces. The particular benefits are the avoidance of damage to the growing crop by the passage of wheels during selective harvesting and the ability to travel on the land at any time. The specification of the experimental vehicle is discussed and consideration is given to possible developments to meet particular requirements. Some observations are made on the performance of a commercially constructed gantry operating on a vegetable growing farm.

Terramechanics research in the Soil Section of the Scottish Institute of Agricultural Engineering

This is a documentary article describing the Institute's work concerning terramechanics. A brief history of the Soil Section outlines its purpose in relating the characteristics of agricultural machinery, the physical properties of soils and crop growth behaviour. The facilities of the Soil Section are described and its success in developing a high-resolution gamma-ray probe to measure soil bulk density and a recording penetrometer is described. Soil compaction measurements have been carried out for alternatives to the conventional tractor wheel and use of a drop-cone to measure soil plastic limit has been developed. Current efforts are focused on performance measurements of multiple-wheel configurations, four-wheel-drive tractors, consideration of soil compaction under modern crawler tracks and research on the effects on crop yield of soil loosening below normal ploughing depth. Development of prediction models for soil compaction is a major interest.

The national tillage machinery laboratory

The development of any science is the accumulation and systematic arrangements of facts about a subject. The facts may come from deductive reasoning or experimentation bu in the final analysis the general laws developed must be tested and accepted. At the National Tillage Machinery Laboratory, a research facility of the U. S. Department of Agriculture, the staff is engaged in determining and studying the laws which govern the reaction of soil to forces. The primary aim is to learn about factors which can be applied to the design and use of tillage implements and tractive devices, such as wheel and crawler tracks. Many of the studies are cooperative with industry and state and federal research groups.