Control of dynamic biped walking machine with limited friction in foot | Author : Borina A.P. | Abstract | Full Text | Abstract :A non-trivial problem in the biped walking is the preservation of stability under external influences without slowing down velocity. A dynamic walking control algorithm with a hierarchical structure is proposed in the article. The lower control level is organized according to the principle of tracking drives and ensures the position of the robot`s body using all given possible coordinates. The problem of traffic stabilization is solved at the upper level. An ideal mechanism — a flat inverted mathematical pendulum is considered in the feedback circuit. Its equations are synchronized by the moment of the step ending. Particular attention is paid to the interaction of the robot foot with the support surface to determine the conditions for the absence of slippage. Proposed control approach makes it possible to control the current position of the robot`s structure in the space in different walking modes without slowing down velocity. Critically assessing the results and prospects of the research, we can conclude about their use-fulness in the development of artificial intelligence cooperation with humans, about possible applications in everyday life, a specific environment and industry. The proposed approach may be applicable to the control of the walking mechanisms of similar mobile robots. |
| Modeling the position of tracked chassis in motion in the event of mechanical characteristics of separate drive electric motors of track contours | Author : Goncharov K.A. | Abstract | Full Text | Abstract :Deviation of the mechanical characteristics of electric motors from the nominal values during their simultaneous operation in the structure of multi-motor drives can destabilize the accuracy of predicting the behavior of the entire mechanical system. The use of electric motors in the structure of a separate drive of the tracked chassis circuits with a random combination of deviations of their sliding can both enhance the factors contributing to the relative run-up of the circuits and compensate for them depending on the function of the change in the motion resistance coefficient over time. This article provides a description of the process and results of modeling the position of the tracked chassis in motion when the mechanical characteristics of the electric motors of the separate drive of the tracked circuits deviate. The proposed mathematical model, on the one hand, takes into account the possibility of changing the coefficient of resistance to movement over time, and on the other hand, it operates with a variable approach to determining the speed of movement of tracked circuits based on a system of sliding deviations of electric motors. Taking into account the results obtained, recommendations were proposed for the selection of electric motors for the circuits of tracked chassis. |
| Experimental modeling of the relationship between adhesion and friction forces in assessing the stickiness of materials | Author : Grigorev P.A., Sladkova L.A. | Abstract | Full Text | Abstract :Sticking of various materials on contacting surfaces is a problematic task in various areas of the national economy, as it leads to an increase in digging efforts, a decrease in productivity and, as a result, an increase in economic costs. For ground-based transport and technological complexes, soil sticking is characteristic of the surfaces of the working bodies of earthmoving and agricultural machines, conveyor belts, walls of mixing plants, etc. The process of sticking has not been fully studied, both from the standpoint of experimental and theoretical studies. Experimental modeling of the detection and evaluation of stickiness will reveal not only its physical nature, but also find certain relationships and dependencies in the evaluation of the friction forces of the soil, which indicates their change in the direction of increase with a decrease in the speed of movement of the contacting body. The reason for this is the presence of sticky forces between the contacting surfaces. The results obtained were achieved on the basis of mathematical apparatus and energy efficiency, as well as modeling the process of changing friction forces de-pending on the adhesive properties of the surface. |
| Improving the traction calculation of dump conveyor belts for mobile construction and road vehicles | Author : Grishin A.V. | Abstract | Full Text | Abstract :A modification of the design method for dump belt conveyors of mobile construction and road machines is proposed, based on the introduction into its structure of refined recommendations for choosing the coefficient of resistance to the movement of the belt, developed on the basis of experimental studies of the heating process of conveyor elements from the moment of its start to exit to operating temperature. Using the example of a dump conveyor of a mobile washing plant, patterns of operation of short conveyors have been identified, which make it possible to increase the efficiency of their design process, as well as to obtain a positive economic result from the use of the proposed modification. |
| Approximation of the static elastic line of the carrying rope in the traction calculation of single-span mobile ropeways | Author : Lagerev A.V. | Abstract | Full Text | Abstract :During the operation of cargo and passenger aerial ropeways, carrying-traction ropes are subject to natural sagging under the influence of their own weight, transported cargo or passenger cabins, wind and temperature effects. The ability to model the geometric shape of a rope, taking into account the conditions and operating modes of ropeways, is necessary when designing and modeling work processes in the rope system, optimizing the design and characteristics of the drive and tension mechanisms. This article presents a method for determining the analytical dependence approximating the configuration of the static elastic line of the carrying-traction rope, in relation to the problem of trac-tion calculation of single-channel single-span mobile ropeways. The peculiarity of the proposed approach is to take into account the inequality of the tension forces of the carrying-traction rope at the ends of the span, which makes it possible to more adequately reflect the real situation. |
| Mathematical model of a stacker crane with a slewing boom | Author : Korytov M.S., Bezrodina A.E. | Abstract | Full Text | Abstract :The widespread use of racking stacker cranes is due to the spread of automated warehouses. Reduction of energy costs when using stacker cranes is one of the main directions of their improvement. The development of mathematical simulation models of stacker cranes allows to determine the energy costs of cargo movement at the stage of design and research. For a new design of the racking crane-stacker, having a rotary boom with a cargo carriage moving along it in the radial direction, a mathematical model in the form of a system of Lagrange differential equations of the second order has been developed. The system of differential equations took into account the energy losses according to the model of viscous friction in the moving links of the boom and the load carriage of the crane. For this purpose, when deriving the differential equations, the Rayleigh function was used, as well as analytical expressions of the potential and kinetic energies of the moving links of the crane, which were differentiated. With the help of typical blocks of the Russian simulation modeling system SimInTech, the obtained system of differential equations was realized in the form of a block diagram. The use of blocks of proportional-integral-differentiating regulators in the simulation model allowed to realize the principle of working out the given trajectory of movement of the crane links, and the numerical integration of the current powers of the boom and carriage drives allowed to determine the accumulated total energy consumption of the drives at a given displacement. The current values of drive powers were determined as products of moments and forces of drives on the speeds of the corresponding links of the boom and carriage. As an example, when running the simulation model, the time dependences of the coordinates of the boom and load carriage of the crane, as well as the moments and forces of the drives, power and work during the movement from a point with zero coordinates to a point with specified coordinates and back. The developed simulation mathematical model is intended to determine the energy costs in the drives of a new design crane with a rotating boom at given displacements of links, as well as, in the future, to verify the control algorithms. |
| Analysis of technical and organizational capabilities of special wheeled chassis for the deployment of mobile ropeways based on airmobile rope units | Author : Shatunova E.A., Lagerev I.A. | Abstract | Full Text | Abstract :Mobile ropeways based on airmobile rope units are a new constructive type of cargo and cargo-passenger ropeways for the rapid deployment of transport and overloading activities in hard-to-reach areas and high-altitude territories. The article analyzes the technical and organizational capabilities of the method of ground delivery of the necessary main and auxiliary technological equipment to the place of loading on air transport using special wheeled chassis of increased load capacity and cross-country capability. Based on the example of Russian-made multi-axle all-terrain vehicles and based on the analysis of their technical characteristics, recommendations for their use are made based on the required overall dimensions and weight of airmobile rope units. Based on the principle of ensuring the universality of the overall dimensions of airmobile rope units in transport condition for combined transportation by various modern types of ground, air and water transport, the possibilities of using road transport for the transportation of airmobile rope units, the overall dimensions of which correspond to the dimensions of universal and aviation transport containers, are considered. |
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