scholarly journals Modeling Movement of Supports of Walking Machines with Dynamic Stability by Using a Stand

2021 ◽  
Vol 31 (1) ◽  
pp. 80-96
Author(s):  
Yury G. Aleynikov ◽  
Otari N. Didmanidze
Keyword(s):  
Experimental Studies ◽  
Electronic Systems ◽  
Process Data ◽  
Walking Machine ◽  
Walking Machines ◽  
Load Sensor ◽  
Cyclic Algorithm ◽  
Algorithmic Model ◽  
Support Motion ◽  
Modern Technologies

Introduction. Walking machines have been interesting for decades. Modern technologies make it possible to create new designs with digital control. Creating software that allows a walking machine to move independently is a difficult task. Walking machine onboard computer needs to process data from sensors in real time. The article demonstrates design and algorithms used to control the motion of an experimental walking machine. Materials and Methods. To simulate the motion of a walking machine and experimental studies, a stand replicating all the electronic systems of the machine was made. The order of rearrangement of the supports during the motion and the trajectory of the support movement are shown. The design of sensors and their principle of operation are considered. The simulation bench with a description of its electronic components is demonstrated. Results. The optimal parameters of the support motion are determined. A cyclic algorithm for specifying the motion of a support along a trajectory consisting of rectilinear segments is described. The problem of synchronization of motion of a set of supports using multithreaded asynchronous programming adapted for multidimensional processors has been solved. The process of lowering the support to the surface and the response of the cyclic algorithm to changes in the shock and load sensor readings are simulated. Discussion and Conclusion. An algorithm for propulsion with reaction to changes in sensor readings has been developed. The conducted research allowed us to obtain an optimal algorithmic model of motion, to which it is easy to add new reactions of the automatic motion control system based on sensor readings.

Features of slopes overcoming by walking devices

2021 ◽  
Vol 9 (3) ◽  
pp. 234-240
Author(s):  
Vadim Chernyshev ◽  
Vladimir Arykantsev ◽  
Anton Goncharov ◽  
Nikolay Sharonov
Keyword(s):  
Mobile Robots ◽  
Experimental Studies ◽  
Field Tests ◽  
Soil Conditions ◽  
Adhesion Properties ◽  
Walking Machines ◽  
Volgograd Region ◽  
Propulsion Unit ◽  
Force Characteristics ◽  
Robot Body

For mobile robots designed to work in extreme conditions, an important characteristic is the value of the overcoming slope. For wheeled and tracked vehicles, the angle of the overcoming slope is limited by the adhesion properties of the soil. The walking device can provide overcoming of higher slopes, since the analogue of the adhesion coefficient for walking machines, with a large footprint track depth, can be significantly greater than 1. The paper discusses the results of experimental studies of the features of overcoming slopes by a walking device in weak soil conditions. When mobile robots overcoming inclines, they may overturn or slide downhill. It is shown that on soft soils the sliding of walking machines downhill is unlikely because of significant deformations of the soil under the support elements. On the other hand, the deformation of the soil worsens the resistance of the walking vehicle to overturning. A method of increasing resistance to overturning by controlling the position of the robot body by separately regulating the conditional clearance of walking mechanisms is considered. The possibility of adjusting the clearance in the propulsion unit on the basis of Umnov-Chebyshev cyclic walking mechanisms is shown. Climbing slopes requires a certain amount of traction. The values of the additional power and the force characteristics of the walking device’s drive necessary for successful overcoming of slopes have been determined. The results of the work can be demand in the development of walking machines and mobile robots. Key words Mobile robots, walking machines, interaction with the ground, traction and coupling properties, overcoming slopes, tipping resistance, mathematical modeling, field tests. Acknowledgements Research was partially supported by RFBR and the Administration of the Volgograd region, research projects no. 19-08-01180 a, 19-48-340007 p_a.

Research on Heat and Mass Transfer of Flat Grooved Heat Pipes

2015 ◽  
Vol 733 ◽  
pp. 599-602
Author(s):  
Lei Cao ◽  
Guo Chang Zhao ◽  
Li Ping Song ◽  
Tian Dong Lu
Keyword(s):  
Heat Transfer ◽  
Mass Transfer ◽  
Temperature Control ◽  
Experimental Studies ◽  
Heat Pipes ◽  
Electronic Systems ◽  
Temperature Uniformity ◽  
Flat Surfaces ◽  
Flow And Heat Transfer ◽  
High Degree

Flat grooved heat pipes, which are especially useful in obtaining a high degree of temperature uniformity on flat surfaces, have been successfully used in the temperature control of electronic systems, however, the mechanisms governing the flow and heat transfer of this kind of heat pipes are still under scrutiny as some reported results cannot be reproduced by others or some assumptions have been proven to be unreasonable or ideal. The theoretical and experimental studies on flat grooved heat pipes and introduce work performed on modeling flat grooved heat pipes are reviewed in this paper.

Design and Underwater Tests of Subsea Walking Hexapod MAK-1

2016 ◽  
Author(s):  
Vadim V. Chernyshev ◽  
Vladimir V. Arykantsev ◽  
Andrey E. Gavrilov ◽  
Yaroslav V. Kalinin ◽  
Nikolay G. Sharonov
Keyword(s):  
Movement Control ◽  
Experimental Tests ◽  
Energy Usage ◽  
Walking Machine ◽  
Walking Machines ◽  
Sea Bottom ◽  
Different Types ◽  
Robotic Devices ◽  
And Control ◽  
System Power

An important role among machines for sea bottom exploration is assigned to the autonomous ground devices. Some rescue tasks also require subsea robotic devices. The main purpose of the work is to investigate and improve adaptive characteristics, traction properties and control methods of cyclic walking movers in underwater conditions. Traction properties of walking machines, which moves at sea bottom was analyzed. Some experience of development and experimental tests of the walking robot “Vosminog”, designed for work at weak and waterlogged grounds. Dynamic model of a walking machine has been shown. Studied an opportunity to increase adaptive characteristics and shape passableness of walking machines. Also design and results of underwater tests of subsea walking unit MAK-1 are discussed. During tests the performance of a walking unit has been checked and the influence of design features of a walking mover on its traction characteristics and ground passability has been investigated. Some details about control system, power system and energy usage, vertical motions and accelerations for different types of walking and conditions of movement has been given. Also, certain attention was given to testing of methods of standalone movement control of subsea unit in conditions of incomplete and ambiguous vision of current situation. Tests have shown that walking movers in subsea conditions can provide higher traction properties, in comparison with wheeled and tracked ones. The unit can be used for exploration of seabed resources and for rescue tasks.

The Mechanics of Parallel Mechanisms and Walking Machines

1994 ◽  
Vol 208 (6) ◽  
pp. 367-377 ◽  
Author(s):  
S J Zhang ◽  
D J Sanger ◽  
D Howard
Keyword(s):  
Parallel Mechanism ◽  
Virtual Work ◽  
The Body ◽  
Position Vector ◽  
Parallel Mechanisms ◽  
Active Joint ◽  
End Effector ◽  
Walking Machine ◽  
Walking Machines ◽  
Fixed Base

A parallel mechanism is one whose links and joints form two or more serially connected chains which join the fixed base and the end effector The mechanism of a multi-legged walking machine can be considered as a parallel mechanism whose base is not fixed and whose configuration changes during different phases of its gait. This paper presents methods for analysing the mechanics of parallel mechanisms and walking machines using vector and screw algebra Firstly, displacement analysis is covered; this includes general methods for deriving the position vector of any joint in any leg and for calculating the active joint displacements in any leg. Secondly, velocity analysis is covered which tackles the problem of calculating active joint velocities given the velocity, position and the orientation of the body and the positions of the feet. Thirdly, the static analysis of these classes of mechanisms using the principle of virtual work and screw algebra is given. Expressions are derived for the actuator forces and torques required to balance a given end effector (or body) wrench and, in the case of a walking machine, the ground reactions at the feet. Numerical examples are given to demonstrate the application of these methods.

Optimal tripod turning gait generation for hexapod walking machines

Robotica ◽  
2000 ◽  
Vol 18 (6) ◽  
pp. 639-649 ◽  
Author(s):  
S. Miao ◽  
D. Howard
Keyword(s):  
Rotation Angle ◽  
Gait Generation ◽  
Walking Machine ◽  
Walking Machines ◽  
Machine Layout ◽  
The Stability

This paper describes an algorithm for generating a tripod turning gait which, when given an arbitrarily located turning centre, firstly maximises the rotation angle (angular stride) and then secondly optimises the stability. It does not require a specific walking machine layout or leg workspace shape, and it can deal with changes in the position of the CG caused by walking on a gradient or by uneven loading.

Basic Design and Synchronized Motion Control for Hexapod Walking Machine

1993 ◽  
Vol 5 (6) ◽  
pp. 511-515
Author(s):  
Katsuhiko Inagaki ◽  
◽  
Hisato Kobayashi
Keyword(s):  
Motion Control ◽  
Distributed Control ◽  
Gasoline Engine ◽  
High Energy ◽  
Basic Design ◽  
Walking Machine ◽  
Walking Machines ◽  
Clutch System ◽  
High Energy Efficiency ◽  
Electromagnetic Clutch

This paper discusses a new mechanism and a new method of motion control for a multi-legged walking machine. The new mechanism provides high energy efficiency which is one of the most important points of walking machines. This problem is solved combining a gasoline engine and an electromagnetic clutch system. In addition, synchronized motion control is also proposed for this mechanism. This control is based on the notion of an autonomous distributed control. Thus, this system has sufficient flexibility and reliability.

Crank Arrangement on the Dynamics of a Quadruped Walking Machine

2015 ◽  
Vol 764-765 ◽  
pp. 213-217
Author(s):  
Fu Chen Chen ◽  
Shang Chen Wu ◽  
Yung Cheng Chen
Keyword(s):  
Dynamic Response ◽  
Dynamic Characteristics ◽  
Pitch Angle ◽  
Walking Machine ◽  
Design And Optimization ◽  
Future Design ◽  
Walking Machines ◽  
The One

The purpose of this study is to investigate the effect of crank arrangement on the dynamics of a quadruped walking machine. The dynamic characteristics of the walking machine, including the stance leg sequence, pitch angle and dynamic response of the quadruped walking machine are investigated and compared with the existing design. The results show that the phrase angle between front and rear legs on the same side should be 0o or 90o and the one between the legs on the different sides should be 180o. The results of this study can serve as a reference for future design and optimization of quadruped walking machines.

Workspaces of a walking machine and their graphical representation. Part II: static workspaces

Robotica ◽  
1996 ◽  
Vol 14 (2) ◽  
pp. 219-226 ◽  
Author(s):  
S.J. Zhang ◽  
D. Howard ◽  
D.J. Sanger
Keyword(s):  
Static Analysis ◽  
Graphical Representation ◽  
Machine Design ◽  
Walking Machine ◽  
Walking Machines

SUMMARYPart I of this paper was concerned with kinematic workspaces of walking machines, while this paper addresses the static workspaces of a walking machine and their graphical representation. The results of static analysis are presented; the static workspace constraints are established; an algorithm for investigation of static workspaces is presented; and the position static workspaces are analysed and graphically represented for an example walking machine design.

Thermal Metamaterials for Heat Flow Control in Electronics

2017 ◽  
Author(s):  
Ercan M. Dede ◽  
Feng Zhou ◽  
Paul Schmalenberg ◽  
Tsuyoshi Nomura
Keyword(s):  
Heat Flow ◽  
Flow Control ◽  
Printed Circuit Board ◽  
Experimental Studies ◽  
Building Blocks ◽  
Circuit Board ◽  
Electronic Systems ◽  
Holistic View ◽  
Anisotropic Thermal Conductivity ◽  
Primary Focus

Rapid advancement of modern electronics has pushed the limits of traditional thermal management techniques. Novel approaches to the manipulation of the flow of heat in electronic systems have potential to open new design spaces. Here, the field of thermal metamaterials as it applies to electronics is briefly reviewed. Recent research and development of thermal meta-material systems with anisotropic thermal conductivity for the manipulation of heat flow in ultra-thin composites is explained. An explanation of fundamental experimental studies on heat flow control using standard printed circuit board technology follows. From this, basic building blocks for heat flux cloaking, focusing, and reversal are reviewed, and their extension to a variety of electronics applications is emphasized. While device temperature control, thermal energy harvesting, and electro-thermal circuit design are the primary focus, some discussion on the extension of thermal-guiding structures to device-scale applications is provided. In total, a holistic view is offered of the myriad of possible applications of thermal metamaterials to heat flow control in future electronics.

Functional fixation and the balanced scorecard

2014 ◽  
Vol 10 (4) ◽  
pp. 540-566 ◽  
Author(s):  
Joachim Schauß ◽  
Bernhard Hirsch ◽  
Matthias Sohn
Keyword(s):  
Cognitive Processes ◽  
Balanced Scorecard ◽  
Management Accounting ◽  
Experimental Studies ◽  
Process Tracing ◽  
Structural Modelling ◽  
Input Output ◽  
Process Data ◽  
Content Type ◽  
Financial Measures

Purpose – This paper aims to examine how balanced scorecard (BSC) users change their judgement processes according to qualitative changes in the BSC. Prior experimental studies have found that decision-makers do not fully adapt their judgements according to changes in financial reports, known as functional fixation. Although previous research has examined functional fixation in several management accounting-related disciplines, the research has not been completely successful in developing a deeper understanding of the cognitive processes that are responsible for the occurrence of this judgemental bias. Design/methodology/approach – To fill this gap, a combination of structural modelling and a process tracing method that monitors participants’ information acquisition to better understand the underlying cognitive processes that affect BSC users’ judgements is used. Findings – Overall, the results indicate that functional fixation is present both from an input–output (structural modelling) and a process tracing perspective. Stable general individual differences, particularly in terms of intuitive versus deliberative preferences in decision-making, influence the probability of functionally fixated behaviour. Additionally, previous findings concerning the over-reliance on financial information in the BSC setting is replicated. Using process data, it was found that BSC users rely more on financial measures than on non-financial measures in the pre-decisional phase of exercising their judgement. Originality/value – This paper contribute to management accounting research on the BSC by investigating two cognitive biases (functional fixation and overreliance on financial measures) from an input–output and a process tracing perspective.

Sign in / Sign up

Export Citation Format

Share Document