Kinematic Diagram Research Articles

The choice of the transmission structure of a wheeled machine for the mechanization of thinning

The article reflects the relevance of the mechanization of work and individual operations in the course of planned thinning in forests of various types. The specific operating conditions of machines used for this type of forestry work are determined. The principles of construction of transmissions of machines for various purposes are considered, a method for determining external parameters and constructing a kinematic diagram of an inter-axle controlled power distribution mechanism in its composition is proposed. The results of kinematic and force analysis for the considered example of the mechanism are presented. Prospects for using the mechanisms of this family are formulated.

Методика решения кинематических задач для произвольной конструкции робота

In this work, we aim to develop a methodology for solving kinematic problems for a robot with a serial connection of links of various movement types. The research methodology included the methods of trigonometric transformations, algorithmization, and programming. As a result, a program for solving direct and inverse problems, and a kinematic diagram of the robot and its working area was developed. The program can be used to optimize the process of developing automated lines based on robots in the field of organizing space or selecting the design of a manipulator. The presented algorithms can be applied in control systems to transform coordinates, thereby shifting from positioning by specifying displacements to positioning by Cartesian coordinates.

Hybrid transmission of a multi-axle wheeled vehicle

The features of the formation of traction and dynamic characteristics of multi-axle wheeled transport vehicles are analyzed. The prospects for the use of electromechanical (hybrid) transmissions of various types as part of the chassis of transport and transport-traction wheeled multi-axle vehicles are analyzed. The principles for constructing kinematic diagrams of hybrid transmissions are proposed, allowing for complete control over changes in the traction forces of individual drive wheels when using the principle of parallel and parallel-series hybrids. Examples of kinematic diagrams of inter-axle and inter-wheel controlled power distribution mechanisms are considered, as well as principles for determining and implementing the values of their external parameters. Attention is paid to the issues of control technology for such mechanisms based on the principle of controlled slipping of the disc friction control element, as well as the prospect of localizing the production of components and assemblies of such transmissions at enterprises of the Russian Federation. Keywords transport vehicle, transmission, power distribution mechanism, mobility, controllability, motion stability

DESAIN KONTROL ROBOT MANIPULATOR KAPASITAS 1.25 kgf

A robotic manipulator is one type of popular industrial robot which has a shape and movement that resemble a human arm. Robotic Manipulator mainly consists of a base, arm, gripper, and control system. This research focused on the control aspect of robot manipulators to handle 1.25 kgf load through experiment as a model of the robot with inverse kinematics. The design of the robot control uses 5 degrees of freedom using a servo motor as its actuator to achieve an accurate and stable movement on its x, y, and z coordinates using a microcontroller to calculate the inverse kinematic in real-time. The robot’s control involved the kinematic system, control diagram, microcontroller, and robot programming. From the experiment, it was found that the robot manipulator was able to grip and move an object from one coordinate to another position accurately and stable with a deviation in each axis were 2-3 mm on the X, 2 mm on the Y, and 1-3 mm on the Z. As for the movement timeframe deviation that was obtained between the programmed and measured was o seconds.

Kinematic joint matrix and block diagram for a group of parallel manipulators

AbstractThere are various matrices to represent parallel mechanisms. It is essential to design a kind of approach to not only denote the parallel structures but also disclose the joint directions. In this paper, a novel methodology called the kinematic joint matrix (KJM) is proposed. It possesses the mapping relations with parallel manipulators with three kinds of kinematic joints. The size of such matrix is smaller when compared with that of topology matrix. A series of two to six degrees-of-freedom parallel architectures is denoted by the KJM. A convenient approach using a special block diagram is introduced to distinguish various kinds of kinematic joint matrices. In addition, detailed comparisons between KJM and topology matrix are investigated. Three regulations are proposed for the latter to be applicable to parallel mechanisms.

Mathematical modeling and computer simulation of the wheeled vibration-driven in-pipe robot motion

The in-pipe robots are currently of significant interest, considering numerous recent publications on this subject. Such machines can use various locomotion principles: wheeled, tracked (caterpillar), walking (legged), screw-type, worm-type, snake-type, etc. In most cases, such robots are equipped with an active drive system transmitting the torque from a motor shaft to the corresponding locomotion mechanism (wheels, tracks, etc.). The present paper is devoted to the wheeled in-pipe robot that doesn’t need a complex transmission. In such a case, the idea of implementing the vibratory locomotion system driven by an internal unbalanced mass is proposed. The corresponding kinematic diagram of the wheeled vibration-driven in-pipe robot is developed, and the differential equations describing the robot motion are deduced. In order to carry out the virtual experimental investigations, the robot’s simulation model is designed in the SolidWorks software. The major scientific novelty of the present research consists in developing the theoretical foundation for designing and practical implementation of the in-pipe robots driven by the inertial vibration exciters and equipped with the unidirectionally rotating wheels and overrunning clutches. The results of numerical modeling and computer simulation of the robot motion substantiate the possibilities and expediency of implementing the proposed vibration-driven locomotion principles while creating novel designs of the in-pipe robots.

Device for generating electrical energy based on thermal expansion of a solid material

Popular renewable energy sources such as hydraulic, wind and solar energy, taken together, cannot completely replace natural sources. As a new alternative, this paper considers the thermal expansion energy of a solid material. A kinematic diagram and the principle of operation of a device that converts the thermal expansion energy of a steel rod into electricity are presented. Calculations show that new materials with given characteristics are needed to produce sufficient power.

Kinematic diagram of the mechanism and algorithm for controlling the width of the indoor structure exhaust opening

The results of theoretical studies of the possibility of reducing the lack and excess of heat in the cultivation structure by substantiating the parameters and algorithm of the mechanism of real-time control width of the exhaust opening are presented. A kinematic diagram of a flat lever mechanism for controlling the width of the draft opening with a drive from an electric linear actuator has been developed. Dependences of the angle of inclination of the leading link of the mechanism and the width of the exhaust opening on the stroke of the actuator rod are determined. The maximum travel of the actuator rod is 225 mm, which allows you to change the width of the exhaust opening from 0 to 900 mm. In this case, the angle of the axis of the master link position sensor varies from 0 to 90 degrees. Based on the analysis of the operation process of the mechanism and the requirements of the plants to the ambient air temperature, an algorithm for controlling the width of the opening was developed, providing for three possible situations. As long as the air temperature meets the biological requirements of the plants, the width of the exhaust opening does not change. If the air temperature exceeds the upper limit, the width of the opening is increased by the value determined by the angle change step of the mechanism driving link. If the air temperature is less than the lower limit, the controller turns on the linear actuator to reduce the opening width. This ensures that the tilt angle of the master link changes by the step dA, which is set during the programming. Logic operators compare the current value of the angle of inclination of the master link with the calculated value and switch the actuator on and off. Thus, the proposed algorithm consistently approximates the state of the system to the optimum zone and reacts to the changes in external conditions.

Mobility Analysis of Reciprocal Frames

Reciprocal Frame (RF) is a three-dimensional grillage structure that consists of mutually supported elements. In RF, whatever the composition that is built, the geometry should always have two members that are connected at a time. Moreover, at least three members should be connected to create a grid, but there is no limit for the maximum. In the research that has been done until today, the geometry of RF, form-finding issues, connections, structural behavior, fabrication methods were studied, but there is very limited number of studies about kinetic RF. In this study RF structures for single loop 3-, 4-, and 5-nexor configurations are analyzed in terms of their motion capabilities. The kinematic diagrams are drawn and their mobilities are calculated. Zero, single, and multi Degrees of Freedom (DoF) configurations are obtained. It has been found that the configurations with revolute joint series get minimum value and also it is not necessary to use as many joints as possible or joints with as many DoF as possible in the configuration to get maximum mobility value.

Use of microelectromechanical measuring systems to stabilize the spatial position of the platform

With the growth of sea freight, as well as cargo operations at sea, in particular the transfer of cargo in difficult climatic conditions, there is a need for automated systems. Such systems can compensate for the disturbing effects of the rolling of ships and allow the safe transfer of cargo on the high seas. One such system is an automated cargo receiving platform located on the receiving vessel. To assess the feasibility of its construction and efficiency of work, a physical model of an automatic stabilized platform has been developed using micromechanical measuring systems that ensure its stabilization in the horizontal plane. In the course of building the model, its functional and kinematic diagram was developed. The problem of processing the received «raw» data from microelectromechanical sensors: a gyroscope and an accelerometer has been solved. Control algorithms are constructed using a PID controller in the program code, as well as a complementary filter for combining accelerometer and gyroscope readings. The work of the model is to keep the platform in a horizontal plane; regardless of the movement of the base (the vessel on which it is installed). The created model showed high efficiency, fast response, positioning accuracy. The stabilization system developed on the basis of the simulated one is capable of working in difficult conditions, ensuring safety when loading on the open sea. Based on the developed model of the automatic stabilized platform, the adaptive output control algorithms were tested.

A temporal classification method based on behavior time series data in patients with behavioral variant of frontotemporal dementia and apathy

BackgroundApathy is a common behavioral syndrome that occurs across neurological and psychiatric disorders. An influential theoretical framework defined apathy as the quantitative reduction of self-generated voluntary and purposeful behaviors. There is evidence in the literature of the multidimensional nature of apathy with cognitive, behavioral, and emotional dimensions. To date, apathy has been assessed using various scales and questionnaires. Alternative objective and ecological measurements of apathy are needed. New methodWe used the ECOCAPTURE protocol and an ethological approach to investigate behavior in bvFTD patients under ecological conditions (a waiting room) while they freely explored a novel environment. Data were collected by behavioral coding from 7-minute video using an ethogram and transformed into behavior time series data. We present an approach considering behavioral kinetics to assess behavior. We aimed to construct a new behavior analysis method, called ECOCAPTURE kinetics, using temporal classification for behavior time series data analysis. To develop our classifier, we retained a nonelastic Euclidian metric, combined with a convolutional approach. ResultsWe applied the ECOCAPTURE kinetics method to a cohort of 20 bvFTD patients and 18 healthy controls. We showed that bvFTD patients can be classified according to their behavioral kinetics into three groups. Each subgroup was characterized by specific behavior disorders and neuropsychological profile. Comparison with Existing Method(s)The ECOCAPTURE kinetics method is different from those of the classical approach of measuring behavior, producing time budgets, frequency of behavior occurrences, or kinematic diagrams. ConclusionsThis approach can be extended to any behavioral study encoding time.

Rationale for the Design of the Stand for Dynamic Testing of Drive Wheels of Agricultural Transport and Technological Machines

Introduction. The development of agricultural production technical support implies the creation of new working tools and machines for soil treatment, and their improvement and research. This process is continuously associated with the use of soil channels and experimental facilities that help to determine the nature of interaction of working elements and wheeled drivers of agricultural machinery, including means of small-scale mechanization, with the soil. The purpose of this study is to provide the rationale for the design of the stand for testing the working elements of tillage units and wheels of transport and technological machines in the agro-industrial complex. Materials and Methods. In order to obtain reliable experimental data on the interaction of wheeled propellers of small-scale mechanization with the soil, the analysis of the basic design of the experimental stand to study the working elements of agricultural machinery was conducted. The requirements for the experimental stand were defined. The experimental-measuring complex “Soil Channel” was developed and manufactured on the basis of production facilities of the Prof. Leshchankin Chair of Mobile Power Tools and Agricultural Machinery of the Institute of Mechanics and Power Engineering of National Research Mordovia State University. Results. The analysis of ensuring the stability of translational motion of the experimental stand movable module is given, the technical solution to ensure the uniformity of its motion is substantiated and the choice of the electromagnetic powder brake type size is made. The kinematic diagram and a prototype of the movable module of the experimental stand for the investigation of the driving wheels of power tillers are developed. Discussion and Conclusion. Improvement of the soil channel design by introducing a removable module into it, will provide tests not only of active, traction and traction-driven working tools of tillage machines, but will also allow studying the nature of interaction of their driving wheels with the soil, carrying out simultaneous control of traction force and slipping. These data can be used for modernization of existing machines and working tools, and for developing new units.

Аналитическое решение первой задачи динамики манипуляторов

The aim is to solve the problem of deriving an explicit analytical form and the cumbersome of the equa-tions of dynamics of body systems. The research methods refer to the mechanics of body systems and systems analysis. The research results allow to write out formulas for calculating forces and moments of forces in the joints of the systems of bodies with one open branch. It is demonstrated in examples of writing out analytical types of equations of dynamics of industrial robot arms with three and six degrees of freedom in space. Three kinds of equations of dynamics were obtained for such manipula-tors. The first equations are written out in scalar-coordinate form with explicit quasi-accelerations and ve-locities, whose role is played by the projections of absolute angular accelerations and velocities of bodies on their connected axes. The second ones are written in vector-matrix form and are obtained from the former in the process of replacing quasi-accelerations by relative linear and angular accelerations of bodies with the allocation of a symmetric matrix of inertial coefficients. The third kind of equations of dynamics is ob-tained from the second one in the process of replacing quasi-velocities by relative linear and angular veloci-ties of bodies. In the third form, the centrifugal, Coriolis, and gyroscopic inertial forces are clearly ex-pressed. Gyroscopic inertial forces allow us to simplify the formula for calculating the power consumption of drives, as well as to simplify the Timofeev formula for calculating the driving forces and moments of forces that provide control of the program motion of manipulator bodies with a given quality. A technique for reusing formulas for manipulators with matching kinematic diagrams of their subsystems is demonstra-ted in the examples . Geometric, kinematic, static and inertial parameters of bodies are explicitly expressed in the equations of dynamics The multipliers for accelerations and products of velocities in the equations of dynamics are optimal in the sense of the minimum of arithmetic operations (additions and multiplica-tions) required for their calculations. Conclusion. All analytical types of equations of dynamics are veri-fied. They occupy several lines of text and further simplification is practically impossible.

Development of a typical structural diagram of the hydraulic system of short-haul passenger aircraft

The article develops a typical structural diagram of the hydraulic system of short-haul passenger aircraft, obtained on the basis of an analysis of the hydraulic system diagrams of aircraft of this class. This made it possible to carry out a generalized calculation of the required energy characteristics of consumers and the system as a whole for the modes: takeoff, flight and landing, as well as to develop a kinematic diagram and calculate the hydraulic cylinder-lift of the front landing gear. Also in the article, a verification calculation of the cylinder for stability in the supportive position of the rod for compression was carried out.

ПОВЫШЕНИЕ ЗАПАСА ПОПЕРЕЧНОЙ УСТОЙЧИВОСТИ ТРАНСПОРТНОГО СРЕДСТВА ЗА СЧЕТ СОВЕРШЕНСТВОВАНИЯ КОНСТРУКЦИИ ПОДВЕСКИ

The purpose of the study is to develop a suspension design for an energy-saturated heavy-duty vehicle that allows for an increased margin of lateral stability. Transportation work can account for up to half of the total cost of energy and production time. In cargo transportation, vehicles with high energy saturation are increasingly used. At the same time, it is always important to ensure road safety, including through the use of new technologies, materials, and structures. Worldwide, road traffic crashes are one of the leading causes of death and disability. The source of a vehicle accident can be loss of stability and, as a result, its rollover. The article considers the design of the vehicle suspension, designed to increase the lateral stability margin. A general view of the vehicle with the proposed suspension is given, listing the main components and parts. A kinematic diagram of the transfer of forces between suspension elements is given. In addition, a diagram showing improvements in stability parameters as a result of movement of the vehicle body in a straight and curved trajectory is presented. A description of the principle of operation of the proposed design is given. Presented relationship of torque relative to tipping point versus centrifugal force dependent on turning radius, vehicle weight and speed. The above formulas allow a comparative calculation of the performance of serial and vehicles equipped with a suspension of the proposed design. Due to the use of the design of the proposed suspension, an increase in the average speed and, as a result, the productivity of transport operations is due.

Частотний аналіз вала електромеханічного приводу малого мобільного робота

Problem statement and the research purpose. The implementation and use of mobile robots in the most diverse spheres of human activity is currently an urgent task. At the same time, ensuring their reliable operation and functioning determines their effectiveness to a certain extent. Using the appropriate calculations during the designing process of various machines, in particular of mobile robots, it is possible to increase the reliability and reduce the material consumption of the developed machine prototypes, and therefore to reduce the cost of its production and maintenance. Methodology of the study. For a small mobile robot with an electromechanical transmission, a number of calculations were carried out according to the developed methodology. The latter contains geometric, kinematic, dynamic, energy, technical and economic calculations, strength and rigidity analysis, and modal analysis of resonance frequencies of oscillations of the workpiece being designed. Results of the investigations. On the basis of the kinematic diagram of the robot’s electromechanical transmission, a solid-state model of the traction (driving) sprocket shaft of the crawler (track-type, caterpillar) drive was developed, for which the necessary safety assurance factor of the shaft material was determined on the basis of the schematized (linearized) Serensen-Kinasoshvili diagram of the critical stresses. Scientific novelty. The article presents an example of a modal analysis of a designed robot’s transmission shaft and determines the resonance frequencies of its oscillations. It was established that the most dangerous resonant frequencies for the designed shaft are equal to 11 Hz, 170 Hz, and 914 Hz. Practical value of the results. The developed technique can be effectively implemented while designing new experimental and industrial prototypes of mobile robots. Scopes of further investigations on the subject of the paper. Further research can be focused on the development of a complex methodology for calculating and designing the electromechanical drives of mobile robots taking into account geometric, kinematic, dynamic, energy, technical and economic calculations.

Creation and analysis of a flight attendant platform

Flight simulators have been used for a long time to train pilots of any type of aircraft. This type of training is more economical. The flight simulator improves control skills in extreme situations with minimal risks for the future pilot. Training on a flight simulator makes it possible to reproduce adverse weather conditions at any time. The pilot is on the ground in a special cockpit, which is mounted on a movable platform. This system is needed to ensure flight conditions as close to real as possible. The subject of the research in the article is an aviation simulator on the Stewart platform. The aim is to create and analyze an flight simulator platform using software. The paper presents the already existing flight simulator and its characteristics. Taking into account its dimensions and weight, the platform is modeled in SolidWorks. The kinematic diagram of the type design (6-6) is selected and presented. The basic equation of dynamics for calculating platform motion law for given values of the control forces is given. Also using this equation it is possible to find the controlling forces knowing the law of motion. The developed 3D model consists of two platforms, a movable and a stationary one. The legs with automatically variable length are attached to the platform using hinges. Selected material aluminum alloy type 2024 from which the platform is created. Selected material aluminum alloy type 2024 from which the platform is created. Static analysis of the loaded platform was performed. By loaded platform is meant that in the places where the simulator and the pi-lot's seat are installed, loads equal in weight to the simulator and the maximum weight of the seat with the pilot are applied. The anal-ysis includes such epurfaces: loads to assess whether the structure can support a given weight, displacement, deformation, safety margins and a Design Insight plot to evaluate design details. Identification of elements that are most likely to start collapsing under the weight of the simulator. The research was performed using SolidWorks Simulation software. Based on the data obtained from the plot, conclusions were made about the performance and safety of the developed platform.

ASPECTS REGARDING THE KINEMATIC ANALYSIS OF POWER TRANSMISSION FROM HELICOPTER DESIGN

The main power transmission of helicopters is a complex technical system, which fulfills its functional role of transforming the kinematic parameters from the turboshaft into the kinematic parameters necessary for the optimal operation of the main rotor of the helicopter. The paper presents a method of kinematic analysis of the power transmission for the main rotor and the anti-torque rotor of a helicopter. Based on the kinematic diagram of this mechanical transmission, the angular velocities and the transmission ratios achieved by the double-planetary gearbox of the main and the secondary transmission are determined.

Physical features of control of the surface relief of precision products

The quality precision measurements of the product manufacturing or their surface treatment are considered. The importance of high-precision measurements at high speed, which does not require delivering the product to a special control laboratory, is shown. A precision laser measuring system is developed and manufactured, its kinematic diagram is presented and the calibration process is described. The verification of the measuring process results is given on the example of the parts obtained by polishing and grinding the surface. The dependence of the measurement error calculation is given, it is shown that the error of the measuring system is within acceptable limits. The presented measuring system has the capabilities of processing measurement results and constructing 3D images. Thus, the possibility of obtaining the surface topography parameters in accordance with ISO 25178-1, 25178-2 is shown. The methods of the surface treatment and filtering are used to improve the result accuracy of measuring the manufactured part quality, among which the elimination of the average slope, median filtering, and Wiener filter are described. It is shown that the highest accuracy of measurement results in the nanometre range with minimizing distortion losses is possible using the Wiener filter.

THE DESIGN OF THE TOROIDAL PLANETARY TWO-ROW VARIATOR OF VEHICLES WITH INCREASED REQUIREMENTS FOR THE RANGE OF GEAR RATIOS AND SMOOTH RUNNING

The article presents the design of the toroidal planetary two-row variator, variants of designs of control units of this variators and a method for calculating planetary mechanisms with inclined axes of satellites. (Research purpose) The research purpose is in developing kinematic and schematic diagrams of a two-row planetary variator; formulating and propose the methodology for calculating gear ratios, angular velocities of satellites and geometric transmission parameters; proposing variants of the variator control unit for the purpose of adaptation or unification with agricultural machinery units. (Materials and methods) The research used data from domestic and foreign authors concerning the design and theoretical description of in-line and planetary friction variators, including toroidal. Authors conducted a patent study of design options for friction planetary variators, the gear ratio of which is changed by changing the position of the satellite axes. Kinematic schemes of the proposed design options were compiled in order to develop a method for calculating gear ratios. (Results and discussion) The article presents the design that can be used in transmissions of transport and traction machines operating in the agricultural sectors. It favorably compares with analogues in small axial and overall dimensions, less wear of friction surfaces and a large range of regulation. The range of such planetary variators, designed on the basis of a combination of increasing and decreasing rows, favorably compares with the range of friction variators with toroidal rolling bodies. The article also presents the methodology for calculating gear ratios that can be used for planetary mechanisms with satellite axes that are not parallel to the main axis of the mechanism. A parametric scheme allows you not only to obtain the values of the variator gear ratios for given geometric parameters, but also to calculate these parameters automatically at the required gear ratios. (Conclusions) The developed concept of a combination of series gear ratios can be applied in the designs of planetary variators and used as a basis in further scientific developments.