Locomotion System Research Articles

Experimental Analysis of Corrective Insoles Materials

AbstractThe corrective static insole is a medical device meant to protect and support the locomotion system. In case of afflictions or lesions of this system, the insoles play a part in healing and rehabilitation. This study aims at analyzing a personalized insole, designed according to rapid prototyping approach with low expenses in order to assist the rehabilitation of pathologies like flat foot and adjacent complications, redistribution of plantar pressures at feet level but also adjusting postural attitude of walking and standing. The insole is developed following a thorough medical examination in order to establish a diagnosis and then an expert in biomechanics and medical engineering will design the product according to the subject's needs and anthropometric dimensions. The paper also performs the analysis of the materials used for manufacturing the corrective insoles, especially from mechanical point of view by determining the static and dynamic loads that may act upon the device. The study is conducted in Solidworks software environment and provides a finite element analysis of the material used for the personalized insole, in order to provide an efficient and convenient methodology in supporting feet imbalance following a pathology.

Development and assessment of a cleaner locomotive powering system with alternative fuels

Transportation research is critical in every domain of the transportation sector, including the rail sector. For sustainable rail transportation, alternative/cleaner powering options are badly needed which can only be possible with cleaner fuels. This paper presents a proposed hybrid combined engine system consisting of a gas turbine and a molten carbonate fuel cell combined with an internal combustion engine. The proposed system uses ecofriendly fuels in order to increase the engine performance and reduce carbon emissions. The hybrid combined engine is modeled using Aspen Plus and is thermodynamically analyzed. The alternative fuels chosen for this study are hydrogen, methanol, ethanol, and dimethyl ether. It was found that the proposed powering system can produce 4200 kW, which is doubled the power of the internal combustion engine, with 43% and 55% thermal and exergetic efficiencies, respectively. The cooling load of the absorption refrigeration system varies from 442 kW to 615 kW with maximum energetic and exergetic co-efficient of performances of 18.29% and 9.54%, respectively. The CO2 emissions dropped by more than 60% using alternative fuels. In addition, parametric studies are conducted in the operating pressure of the molten carbonate fuel cell (MCFC) and gas turbine (GT). The best performance can be fulfilled at 200 kPa for the MCFC and 900 kPa for the GT. Therefore, the hybrid combined engine can provide high power with less CO2 emissions and high performance.

Analysis of models for image processing when implementing an object detection system on a railway track

With the development of the railway industry, informatization of society and the automation of many technological processes, it becomes possible to create an automatic control system, diagnostics and safety of locomotive movement. One of the most important systems of this complex is the system for detecting objects on railway tracks, ruptures of the railway bed and its turns. Such a system can be developed in the form of a camera installed on a locomotive and information processing systems on board each rolling stock, or a global system for remote processing of information from several locomotives. Regardless of the implementation of the system, there is a need to create a block for detecting objects on images coming from cameras. The implementation of this block is possible using interacting full-convolutional and convolutional neural networks and training on a dataset covering various situations occurring on the railway tracks.

Advances in Agriculture Robotics: A State-of-the-Art Review and Challenges Ahead

The constant advances in agricultural robotics aim to overcome the challenges imposed by population growth, accelerated urbanization, high competitiveness of high-quality products, environmental preservation and a lack of qualified labor. In this sense, this review paper surveys the main existing applications of agricultural robotic systems for the execution of land preparation before planting, sowing, planting, plant treatment, harvesting, yield estimation and phenotyping. In general, all robots were evaluated according to the following criteria: its locomotion system, what is the final application, if it has sensors, robotic arm and/or computer vision algorithm, what is its development stage and which country and continent they belong. After evaluating all similar characteristics, to expose the research trends, common pitfalls and the characteristics that hinder commercial development, and discover which countries are investing into Research and Development (R&D) in these technologies for the future, four major areas that need future research work for enhancing the state of the art in smart agriculture were highlighted: locomotion systems, sensors, computer vision algorithms and communication technologies. The results of this research suggest that the investment in agricultural robotic systems allows to achieve short—harvest monitoring—and long-term objectives—yield estimation.

Advances in Forest Robotics: A State-of-the-Art Survey

The development of robotic systems to operate in forest environments is of great relevance for the public and private sectors. In this sense, this article reviews several scientific papers, research projects and commercial products related to robotic applications for environmental preservation, monitoring, wildfire firefighting, inventory operations, planting, pruning and harvesting. After conducting critical analysis, the main characteristics observed were: (a) the locomotion system is directly affected by the type of environmental monitoring to be performed; (b) different reasons for pruning result in different locomotion and cutting systems; (c) each type of forest, in each season and each type of soil can directly interfere with the navigation technique used; and (d) the integration of the concept of swarm of robots with robots of different types of locomotion systems (land, air or sea) can compensate for the time of executing tasks in unstructured environments. Two major areas are proposed for future research works: Internet of Things (IoT)-based smart forest and navigation systems. It is expected that, with the various characteristics exposed in this paper, the current robotic forest systems will be improved, so that forest exploitation becomes more efficient and sustainable.

Responsive navigation of a biped robot that takes into account terrain, foot-reachability and capturability

A control architecture for robust biped navigation that takes into account traversability on terrain, foot-reachability, and capturability all at once in dynamic situations is proposed. It consists of online mapping of terrain and quick decision of foot placement. A grid map with elevation, normal direction and the standard deviation of measurement is proposed for the former and is named the stochastic Elevation-and-Normal Grid (ENG) map. It is incrementally updated as depth sensor information comes in every cycle. The traversability of each grid can be easily checked based on the associated information. The latter stands upon the canonical biped track (CBT), which is a pair of continuous paths that the feet track. It is drawn along a nominal collision-free path on the ENG map. The most efficient foot placement at the next step from the viewpoint of the foot-reachability is chosen on them as the initial candidate, around which a feasible placement accommodated with traversability and capturability is found by the breadth-first search. An autonomous biped locomotion system is completed by combining the above architecture with a foot-guided controller based on the terminal capturability. The efficacy of the proposed method was validated through some computer simulations.

Pipeline Inspection Tests Using a Biomimetic Robot.

This paper presents a biomimetic prototype of a mobile robot that can be used to inspect the subdrainage conditions of pipelines located along different highways in Mexico. Computer-aided design tools have been used to size each of the prototype components as inspired by anatomical spider structure. Springs are integrated to generate proper contact pressure against the pipe walls. The robot locomotion system is implemented with adaptable behaviour for the irregularities of pipelines along its journey. The robot prototype is manufactured in 3D printing with the advantage of having its spare parts easily replaceable. Reported results show internal pipe status through a mini video camera on the top of the robot.

Development of the performance control algorithm of the blower motors of electric locomotives for various operating modes

The widespread use of electric motors in various electric drive systems and the automatic regulation of their performance are largely determined by the reliability of these machines, the failures of which cause significant material damage and are caused by significant yard time at the depot repair positions. Improving their reliability is a major scientific and technological challenge. When electric locomotives operate on the East Siberian Railway, severe climatic conditions have a direct impact on the reliability of electrical equipment, so the development of an algorithm to control the performance of blower motors for various operating modes is an urgent task. The main parameters of the entire electric locomotive energy system, which largely determine the safety of trains and the amount of throughput capacity of the sections, are the reliability of cooling machines and the algorithm of their operation in different operating modes, taking into account weather and climatic conditions. The immediate accounting and analysis of the causes of the failure of asynchronous electric motors with a short-circuited rotor in the blower drive, the use of which is justified by the simplicity of the design, was the basis for the development of the algorithm proposed in this article. The electric locomotive cooling control algorithm is focused on eliminating or minimizing snow, dust insulation of traction electrical equipment in a given range of regulation. Elimination of the unauthorized shutdown of cooling machines by locomotive crews while the train runs in the slow-down mode, as well as the elimination of the start processes of asynchronous electric motors of the blower motor actuator, will improve the reliability of the entire electric locomotive in general.

Models of Locomotive Traction Drives for the Improvement of Sand Feeding System

In this research, we calculated the key characteristics and parameters of the pneumatic injector using the set input and output gas flow values. We simulated the ejection of excessive air from the ambient to increase the flow rate of the air-and-sand mixture from the outlet chute of the sand feeding system of a locomotive using the CFD package of the FlowSimulation extension of the SolidWorks solid object design environment. We achieved the reduction of the compressed air consumption as compared to the standard locomotive sand-feeding systems.

Jump takeoff in a small jumping spider.

Jumping in animals presents an interesting locomotory strategy as it requires the generation of large forces and accurate timing. Jumping in arachnids is further complicated by their semi-hydraulic locomotion system. Among arachnids, jumping spiders (Family Salticidae) are agile and dexterous jumpers. However, less is known about jumping in small salticid species. Here we used Habronattus conjunctus, a small jumping spider (body length ~ 4.5mm) to examine its jumping performance and compare it to that of other jumping spiders and insects. We also explored how legs are used during the takeoff phase of jumps. Jumps were staged between two raised platforms. We analyzed jumping videos with DeepLabCut to track 21 points on the cephalothorax, abdomen, and legs. By analyzing leg liftoff and extension patterns, we found evidence that H. conjunctus primarily uses the third legs to power jumps. We also found that H. conjunctus jumps achieve lower takeoff speeds and accelerations than most other jumping arthropods, including other jumping spiders. Habronattus conjunctus takeoff time was similar to other jumping arthropods of the same body mass. We discuss the mechanical benefits and drawbacks of a semi-hydraulic system of locomotion and consider how small spiders may extract dexterous jumps from this locomotor system.

On the issue of increasing operational energy efficiency of eight-axle passenger DC electric locomotives

Mass of a passenger train and, accordingly, number of cars in its composition is selected based on the amount of passenger traffic on the section, determined by the seasonal demand for transportation in each direction. In one direction of the section serviced by an electric locomotive, the mass of a passenger train may differ several times from the opposite direction, which depends on the destination station of the train and the period of its circulation. At present, in addition to 6-axle electric locomotives of the ChS2T and EP2K series, more powerful 8-axle electric locomotives of the ChS7 series operate in the same schedule for traction of passenger trains on railway sections electrified with direct current with a voltage of 3 kV catenary. All three series of the considered electric locomotives are designed for a maximum operating speed of up to 160 km/h. In this regard, there is a situation with the underutilization of the maximum speed and excess power of the ChS7 electric ocomotives, especially when operating with passenger trains of medium and low weight and a limited speed of 120 km/h. The comparative data on the specific power consumption of the EP2K 6-axle electric locomotives and the ChS7 8-axle electric locomotives operating in the same schedule, presented in the article, indicate the need to find additional reserves for saving the specific power consumption when servicing passenger trains of medium and low weight with ChS7 electric locomotives. The electric locomotive power system includes traction and auxiliary electric machines. The article discusses ways to turn off part of traction motors, which can be carried out with a standard electric locomotive circuit. However, when one section of the electric locomotive is turned off, the power of the four traction motors remaining in operation is not always sufficient to drive a passenger train according to the schedule. Therefore, a variant of improving the power circuit of an electric locomotive in the process of carrying out its overhaul is proposed. This option represents the modernization of the power circuit of the ChS7 electric locomotive when operating on a series-parallel connection with a pair of traction motors disconnected. As a result, the power circuit of the 8-axle electric locomotive operates similarly to the circuit of 6-axle DC electric locomotives with a collector traction drive. The expected savings in specific power consumption can reach 15% in comparison with the operation of an 8-axle electric locomotive ChS7 in normal mode. Switching off one section of the electric locomotive and further running the train on four traction electric motors will reduce the specific power consumption by up to 25%.

Design, Modeling, and Control of a Single Leg for a Legged-Wheeled Locomotion System with Non-Rigid Joint

This article presents an innovative legged-wheeled system, designed to be applied in a hybrid robotic vehicle’s locomotion system, as its driving member. The proposed system will be capable to combine the advantages of legged and wheeled locomotion systems, having 3DOF connected through a combination of both rigid and non-rigid joints. This configuration provides the vehicle the ability to absorb impacts and selected external disturbances. A state space approach was adopted to control the joints, increasing the system’s stability and adaptability. Throughout this article, the entire design process of this robotic system will be presented, as well as its modeling and control. The proposed system’s design is biologically inspired, having as reference the human leg, resulting in the development of a prototype. The results of the testing process with the proposed prototype are also presented. This system was designed to be modular, low-cost, and to increase the autonomy of typical autonomous legged-wheeled locomotion systems.

Exact Isoholonomic Motion of the Planar Purcell's Swimmer

In this article we present the discrete-time isoholonomic problem of the planar Purcell's swimmer and solve it using the discrete-time Pontryagin maximum principle. The 3-link Purcell's swimmer is a locomotion system moving in a low Reynolds number environment. The kinematics of the system evolves on a principal fiber bundle. A structure-preserving discrete-time kinematic model of the system is obtained in terms of the local form of a discrete connection. An adapted version of the Discrete Maximum Principle on matrix Lie groups is then employed to come up with the necessary optimality conditions for an optimal transfer from a given initial state while minimizing the mechanical energy expended in the presence of constraints on the controls. These necessary conditions appear as a two-point boundary value problem and are solved using a numerical technique. Results from numerical experiments are presented to illustrate the algorithm and compared with the existing results for a similar case in the literature.

Formation of new principles and models of operation of structural units of the industry under the conditions of implementation of digital technologies

The construction of a high-tech modern model “Digital Railroad” is currently a key element, the implementation of which is planned for the near future. The project will create new principles and models for the work of all structural divisions of the industry in the context of the widespread penetration of digital technologies. The emergence of digital technologies will make it possible to transfer the organization and technology of functioning of transport and other systems to a qualitatively new level, new information technologies will make it possible to optimize the operation of rolling stock. According to the results of the analysis of the performance indicators of the service locomotive depot Irkutskoye, according to the model of “full service” of the locomotive fleet, it was revealed that the indicators negatively affects the financial results of the depot and negatively affects the quality of the repair performed in general. To solve this problem, it is proposed to use an automated locomotive fleet reliability management system in the Irkutsk service locomotive depot, the implementation of which will increase the availability factor, reduce downtime in repair depots, and minimize resource consumption for all types of repair and maintenance. The main consumer of the services of the locomotive fleet reliability management system is, first of all, the Russian Railways holding company and the traction directorate. They are interested in the reliable operation of the rolling stock, since during the operation of locomotives there are risks: comments on the operation of the locomotive fleet, failures and malfunctions of various degrees of complexity, cases violations of train traffic safety.

Integrated Management System for Coal Mine Locomotive Transportation

<p>Combined with the reconstruction project of underground locomotive transportation system in Guqiao Coal Mine of Huainan Mining Group, the dissertation studies the comprehensive management system of coal mine locomotive transportation. The accuracy of ZigBee wireless positioning technology is improved through Gaussian filtering to make it applicable to more complex underground coal mine environment. Frequency conversion control is used in the motor control circuit to realize real-time calculation of the running speed of the locomotive. By analyzing the control scheme of the turnout and traffic lights, the explosion isolation and essential safety control sub-station suitable for gas mine are designed. Communication platform construction of the system is realized through wireless base station of Benan mine and industrial network of coal mine. System relevant data can be uploaded to the ground dispatching center in real time, so that the scheduling staff can reasonably arrange the scheduling tasks in a timely manner. The optimized logistics management and storage management system makes the material dispatching and transportation more reasonable and scientific. Through the analysis of the running data, the construction and personnel management of the locomotives are realized.</p>

Simulation Method for the Transport System of a Small-Sized Reconfigurable Mobile Robot

This study focuses on the features of transport (locomotion) systems of mobile mini-robots (MMR), i.e., small unmanned ground vehicles of a portable type measuring several tens of centimeters and weighing no more than 15 kg. A distinctive feature of the considered MMR is the possibility of its both structural reconfiguration (i.e., the ability to function in two options—tracked and wheeled) and geometric reconfiguration in the tracked option (i.e., chassis geometry variation). Thus, the transport system of such a mobile robot is divided into two components: a locomotion subsystem and a chassis geometry variation subsystem. The article examines the factors that are necessary for the correct mathematical description of such a small-sized and relatively high-speed transport system. A method for constructing a computer model of the transport system as an electromechanical device only is proposed. Such a computer model of the MMR transport system is developed for two types of chassis configurations: tracked and wheeled. The experimental studies performed and the comparison of the experimental and simulated data obtained showed their close convergence, within 5 to 7%. Thus, it is shown that the revealed features of the MMR transport systems along with the proposed method for their computer model development considering these features make it possible to increase the accuracy and adequacy of the MMR motion simulation in comparison with previously known approaches used in the computation of larger vehicles. The results obtained make it possible to consider the proposed computer model of the transport system as an electromechanical component of the complete model of a mobile robot.

Functional Design of a Hybrid Leg-Wheel-Track Ground Mobile Robot

This paper presents the conceptual and functional design of a novel hybrid leg-wheel-track ground mobile robot for surveillance and inspection, named WheTLHLoc (Wheel-Track-Leg Hybrid Locomotion). The aim of the work is the development of a general-purpose platform capable of combining tracked locomotion on irregular and yielding terrains, wheeled locomotion with high energy efficiency on flat and compact grounds, and stair climbing/descent ability. The architecture of the hybrid locomotion system is firstly outlined, then the validation of its stair climbing maneuver capabilities by means of multibody simulation is presented. The embodiment design and the internal mechanical layout are then discussed.

Design and implementation of a maxi-sized mobile robot (Karo) for rescue missions

Rescue robots are expected to carry out reconnaissance and dexterity operations in unknown environments comprising unstructured obstacles. Although a wide variety of designs and implementations have been presented within the field of rescue robotics, embedding all mobility, dexterity, and reconnaissance capabilities in a single robot remains a challenging problem. This paper explains the design and implementation of Karo, a mobile robot that exhibits a high degree of mobility at the side of maintaining required dexterity and exploration capabilities for urban search and rescue (USAR) missions. We first elicit the system requirements of a standard rescue robot from the frameworks of Rescue Robot League (RRL) of RoboCup and then, propose the conceptual design of Karo by drafting a locomotion and manipulation system. Considering that, this work presents comprehensive design processes along with detail mechanical design of the robot’s platform and its 7-DOF manipulator. Further, we present the design and implementation of the command and control system by discussing the robot’s power system, sensors, and hardware systems. In conjunction with this, we elucidate the way that Karo’s software system and human–robot interface are implemented and employed. Furthermore, we undertake extensive evaluations of Karo’s field performance to investigate whether the principal objective of this work has been satisfied. We demonstrate that Karo has effectively accomplished assigned standardized rescue operations by evaluating all aspects of its capabilities in both RRL’s test suites and training suites of a fire department. Finally, the comprehensiveness of Karo’s capabilities has been verified by drawing quantitative comparisons between Karo’s performance and other leading robots participating in RRL.

Modelling and control strategies for a motorized wheelchair with hybrid locomotion systems

Several kinematic and dynamic models of conventional motorized wheelchairs in the literature presume the wheelchair movement only on flat surfaces, disregarding the effects of gravitational forces and rolling friction. In addition, there are no many studies clearly describing how the dynamic properties of a conventional wheelchair and stair-climbing wheelchair with a track mechanism are formulated. However, the design of a good controller generally involves the formulation of a comprehensive wheelchair model. This work contributes to the modelling of the motorized wheelchair with hybrid locomotion systems (MWHLSs), which have wheel and track mechanisms to move the wheelchair, regarding the formulation of kinematic and dynamic models for each locomotion system, considering the effects of gravitational forces and rolling friction, on flat and inclined surfaces and climbing stairs. From the mathematical model for each locomotion system, the gearmotor torque control is used, since the torque provides smooth and precise driving. Thus, the open-loop and closed-loop control techniques, such as control Lyapunov function, Backstepping control, and Proportional-Integral-Derivative controller, are designed due to their well-known characteristics. The robustness analysis of these controllers, taking into account the occurrence of external disturbances, indicates which one best assists wheelchair users, providing a safer and more efficient navigation with the MWHLS.

Design of a modular locomotion system for autonomous mobile robots

Autonomous mobile robots are becoming more popular today and are successfully integrated into many civil and industrial projects. In the industrial sectors flexibility and modularity have an important role, so the production can be diversified and achieved with low costs. This paper presents the conceptual and functional design of a modular locomotion system for an autonomous mobile platform that can be configured according to the needs of the industrial environment it serves. The architecture of the locomotion system is based on a spring suspension system and three types of wheels: conventional wheels, omnidirectional wheels and mechanum wheels. The calculations for the chosen suspension system are presented, which ensure the contact with the ground for each type of wheel and the resignation calculations for the engine that will drive the wheel. Finally, some variants of configurations are presented that can be made on an autonomous mobile platform with these modules.