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The paper describes the principle of choosing the optimal size and shape of the supporting element of a walking machine, provided that the maximum possible contact area with the supporting surface is provided for moving on snow or soils with a low bearing capacity. The study was carried out for an orthogonal walking propulsion device, but it can also be used for walking mechanisms of other types.

The prospects of using lidar as an element of technical vision of underwater walking vehicles are discussed. Walking machines appear to be the most suitable for seabed conditions. The proposed elements have a number of advantages over more traditional image sensors. Shown are already existing patents applicable for use in seabed conditions. It is proposed to use lidars for a system of automatic recognition and determination of geometric dimensions of anomalies and structural elements of technological pipelines in the oil and gas industry.

The paper describes the principle of operation of a reversible stepper lift with a jamming type of propulsion, the scheme of which is developed on the basis of an already existing model, and equilibrium equations are provided under the condition of its worst loading on a support.

The results of finite-element modeling of the mechanics of contact interaction of small-sized support elements (feet) of walking machines with weakly bearing soils are discussed. A flat contact task is formulated for rigid feet of a rectangular shape interacting with an elastoplastic supporting surface. Nonlinear models of soil behavior under loading were used. A two-stage iterative algorithm for solving the non-linear problem in the computer system of finite element analysis ANSYS is implemented. The task was solved under conditions of large deformations of the supporting surface. The simulation results showed that a sufficiently large amount of soil is loaded during the interaction of a small foot with a supporting surface. Under normal loading, the greatest stresses and strains occur directly under the foot. Here may be the destruction of the soil. At a standardized depth of 0,5 m, the stress decreases. The top layer of soil remains lightly loaded. In addition to vertical deformations, there is a «squeezing» of soil to the right and left from under the foot. With a tangential load, the stress and strain fields lose their symmetrical nature. The zones of greatest equivalent stresses and strains are shifted towards the action of the tangential load. The greatest ground stresses occur under the foot and on the lateral surface of the foot. In the direction of the tangential load, the entire mass of the soil, including its upper layers, is substantially loaded. Near the foot, in the zone of greatest stresses, a characteristic area appears, where the soil is squeezed up. Here the reverse process of compaction of the soil takes place. It is shown that the use of feet with a small supporting surface leads to an undesirable increase in soil stresses in the contact zone. On the other hand, in small feet, there is a decrease in the soil compaction zone and its upper layer is less loaded. Also, for small feet, the supporting surface is used more efficiently - the stresses along its length are distributed more evenly, and the side surface acts as a grouser.

In underwater conditions walking machines have better ground and shape passability. Control of almost all robotic systems moving on a bottom (underwater bulldozers, cable layers, self-moved ground mining units, etc.) is executed from a surface by the operator according to the visual information from onboard video sensors. Such approach to control of the multi-legged walking machines is not appropriate. The operator cannot to control effectively all legs at the same time and does not manage to make good decisions at emergence of any obstacle in the direction of movement, because of poor visibility. Results of investigation of information opportunities of foot of the cyclic walking mover during collision with an unorganized support surface are discussed. Shown that on the type of self-adapting of foot to an unorganized support surface during collision with an obstacle and the relative movement of the mechanism of walking it is possible to obtain some indistinct information about external working space and the current situation. It can be used at adoption of the correct decisions on control in the conditions of absence of external control signal. In particular, on the basis of fuzzy control algorithms, realization of the standard typical movements which are independently executed by the underwater walking robot for an exception of capsizing and other emergencies is possible.

Industrial exploration of sea bottom requires special underwater technical devices, which moved at sea bottom. Walking machines in seabed conditions, which characterized by sophisticated shape and low bearing ability of the ground, have higher traction properties and possibility, compared with traditional vehicles. In the paper discussed some results of investigation of controlled movement dynamics of walking robot with cyclic mover during obstacle collision without pre-defined parameters. At the base of integration of information from video sensors, was offered situational method to organization behavior of the robot in conditions of incomplete and ambiguous understanding of the current situation and workspace. At the base of fuzzy movement control algorithms were developed typical leg motions, autonomously performed by the robot with the purpose of exclusion of emergency situations. Interactive analysis of the device control system as software model of control object showed, that majority of typical situations on the control can be solved without operator intervention. Experimental verification of gained results of mathematical modeling at the base of underwater walking robot MAK-1 was held. During underwater experiments dynamics of walking device, traction properties and possibility were investigated. In research of possibility were passed local obstacles both straight movement mode and in special maneuvering mode. Some attention during the tests was given to tuning of the robot fuzzy control system in training mode. Results of the work can be demand in underwater walking robotic systems development for underwater technical works and for new industrial technologies of seabed resources reclamation.

Tests show that they are simple and reliable and can work effectively in extreme conditions, for example, on waterlogged and underwater soils. The disadvantage of cyclic walking mechanisms is the constant “program” trajectory of the support point. This limits the abilities of the walking machine on the shape passability. In the underwater walking machine MAK-1, the possibility of adjusting the program movements of the legs was achieved by introducing an additional controlled degree of freedom into the mover. Thus, the control (within a limited range) of the movement of the control points is achieved. Changing the law of motion of the support point leads to a change in the structure of energy consumed by the movement. The paper considers a possibility of mutual compensation of energy consumption for pressing the soil with other components of energy consumption by controlling the movement of the support points of the walking mover. A comparative analysis of energy consumption for the movement of the wheel and walking mover in the low-speed range is also carried out. The analysis is based on the results of dynamic modeling and generalization of experience in the development of experimental walking machines units. It is shown that via controlling the movement of the points of the walking mover, it is possible to achieve a reduction in energy consumption for the ground resistance to the movement of the walking device. The reduction appears at the cost of recuperation of energy spent on lifting the machine body in each cycle of movement.

The expediency of introducing an additional damping device (analog of a shock absorber) into the cyclic walking mechanism of a mobile robot, which provides a dissipative connection of a ski-shaped foot with a support link, is discussed. The influence of the damper on the dynamics of the feet changing and the dynamics of the meeting of the foot with an obstacle is considered. It is shown that dissipation in the hinge of the foot leads to a decrease in the intensity of shock processes when changing feet and when meeting an obstacle, provides a decrease in power losses for vertical vibrations of the body, and also expands the propulsion unit’s capabilities for self-adaptation to an unorganized surface.

Walking machines when working on waterlogged soils can be more efficient than wheeled machines. They provide increased ground passability and destroy the soil to a lesser extent. The paper discusses the results of studies of plant jamming by the feet of walking machines. Stamp tests of contact interaction of feet of various shapes with water-saturated soil were carried out. It was found that the greatest damage to the plant is obtained along the perimeter of the foot. This was the case at any depth of the footprint. Plants damaged by the foot, even in the case of small-sized feet, continued to grow after a period of depression. Wheeled and tracked movers, due to slipping and milling effect, are damaging plants to a higher extent. Mathematical modeling of the contact interaction of the foot with weak-bearing soil by the methods of finite element modeling has been carried out. Dimensional contact model for rigid feet of various shapes interacting with elastoplastic soil is formulated. The task was solved under conditions of large deformations of the supporting surface. The regularities of the stress-strain state of the soil in the zone of its contact with the foot under simple normal loading are obtained. Modeling shows that the greatest stresses occur along the perimeter of the foot, and the soil inside the perimeter is less loaded. This explains the nature of the plant jamming. Thus, the walking mode of movement in irrigated agriculture can provide lower plant jamming in comparison with traditional machines. Considering the smaller area of soil compaction and the absence of a continuous track, which is one of the causes of water erosion of the soil, it can be concluded that it is advisable to use small-sized feet.

In the paper discussed results of investigation of increasing of shape passableness and adaptability to terrain for walking machines and robots with cyclic movers types. Usage of cyclic walking movers allows not to care about gait safety and stability and exclude the necessity in controlled adaptation system. By the other hand, strict trajectory of support points of cyclic type of walking mechanisms restricts abilities of adaptation to support surface and shape passableness of machine. In the paper considered the possibility of passive control of angular position of foot with hinge joint in transfer phase. Cyclic walking mechanism with one controlled degree of freedom was offered, it provides rising of the toe of foot with hinge joint both in straight and reverse movement (without entering an additional controlled actuator). Considered some features of synthesis of similar walking mechanisms. Presented the examples of their design in walking machines, intended for works at weak and waterlogged grounds, the results of real experiments are also shown. Presented, that passive foot control of cyclic mover significantly increases abilities of walking machines to adjust to rough ground and allows to overcome obstacles, which higher than height of support point of walking mechanism by more than two times. Some attention is devoted to the tasks of movement control of walking robotic systems with movers of cyclic type in condidtions of incomplete and ambiguous understanding about obstacle.

Seabed conditions, which are characterized by low bearing ability of ground and rough terrain, often make traditional types of movers inefficient. Walking machines are better for bottom works; they differ in extremely high ground and shape passableness. In underwater conditions, there are certain features of walking mover interaction with ground. In particular, there is “compression effect” on low bearing grounds. At changing of feet, due to rarefaction, which arises under foot in contact phase, the force appears preventing foot breakaway from ground. The paper offers a method of dynamic measurement of the compression effect at subsea ground. The design of electromagnetic stamp device, which is suitable for investigation of the compression effect at subsea ground, is offered. Mathematical modeling its anchor dynamic were carried out during experiments. Based on experimental results of dynamic of the electromechanical system under consideration, a method of processing data of stamp tests has been developed. The obtained results can be useful at development of movers and control systems of underwater walking machines and robots suitable for subsea operations as well as at designing new industrial technologies of seabed resources exploration.