Search

The paper deals with a problem of position and orientation errors of mobile platform of large-sized parallel cabledriven robots. The advantages of parallel cable-driven robots are simplicity of structure and scalability. At the same time, parallel cable-driven robots are difficult to design due to the specific problems such as collision of cables, geometric and structural nonlinearity in the mathematical models of the main elements of the robot. In this paper, we consider the problem of eliminating the uncertainty associated with deformations of the elements of the robot structure. Such a configuration of the cable system is selected, in which the proximal anchor points of some cables can be considered without errors relatively to given positions. The cable system of a large-sized robot is mounted on the towers. The errors in the proximal anchor points relatively to given positions become significant due to the significant deformations of upper sections of the towers. The deformations of the towers in lower sections can be considered insignificant, and the proximal anchor points have to be located no higher than the middle of the tower to be considered corresponding to a given position. The aim is to compensate the position and orientation errors of the mobile platform of large-sized parallel cable-driven robot due to deformations of the cables and towers. The task suppose uncertainty about the coordinates of the proximal anchor points of the upper cables. Cable deformations are determined from Hooke’s law using tensile forces measurement in cables. The problem of compensations is solved in two stages. At the first stage, the approximate bias of the center of mass of the mobile platform along the vertical coordinate is found. It is defined as the height of the truncated pyramid, the edges of which are formed by stretched lower cables. At the second stage, rotation angles of the mobile platform are determined. Using the rotation matrix, biases in the heights of each distal anchor points are found in the tool coordinate system. In the studied cases PID regulation is used, however, more advanced techniques of automatic regulation, for example, optimal control, can provide better results. The tasks are applied to the model of large-sized symmetric parallel eight-cable-driven robot.

The article deals with a description of design and modeling of neuro-fuzzy regulator (ANFIS) which provides a compensation of deviations of mobile platform of parallel cable-driven robot. The regulator uses adjusting of lengths of unwounded cables. Evaluation of the control system has been made according to the quality criterion as an elongation of each cable comparatively to given values.

A laboratory model and simulation of the movement of a mobile robot with a sectional propeller are considered. The results of mathematical modeling of motion dynamics are presented.

The method of overcoming an obstacle of the "moat" type by a walking machine with cycle movers is considered. Quantitative characteristics of the profile passability in indicator are described. The results of experimental research of the proposed method of increasing the profile passability of a walking machine with cycle movers are presented.

The problem of stability of the plane motion of mobile robots, including those with walking propulsion devices, is considered. Two modes of propulsion devices are compared: "pushing" and "pulling". The solution of two model problems on the plane motion of a solid body caused by kinematic and force action is presented.

A study of the specific time of 3D printing using the FFF technology of one gram of material is being carried out. It describes the methodology of the study, using software, and configure it in a study, an analysis of the data and the final results.

We construct a programmed motion of the drive to adapt a walking mover to the supporting surface based on the optimality criterion that takes into account the energy costs of movement, the shockless interaction with the ground, and the traction–coupling properties in stepping.

A few indicators characterizing the efficiency of mobile robots in general and walking robots in particular, as well as operational (motion comfort and energy efficiency) and structural (pace) indicators are considered. A weighted quality functional of quality is constructed and its extreme value is sought. An analytical solution is obtained making it possible to perform a multicriteria optimization depending on the significance of a given indicator and on this basis to determine the optimal motion modes and the walking mover parameters.

The problem of choosing the program regime of a cycle mechanism motion on the basis of complex estimates of its energy and dynamic parameters is solved. An optimization criterion is formed as a functional consisting of the introduced parameters, which are determined by solving some differential equations describing the mechanism motion. For a specific mechanism, an example of complex estimate of its efficiency is given. An application procedure for the proposed method is discussed.

A method for determining programmed motion laws of a modular multisupport walking machine with several twin orthogonal rotary movers is considered. Arbitrary planar motion of this machine without slippage of the feet on the ground is studied. The machine control is formed by a matrix of control actions. Simulation results are discussed.

We consider cyclic mechanisms with one degree of freedom driven by engines of various types such as alternating and direct current motors, internal combustion engines, etc. We pose the problem of modifying the mechanism structure by joining additional links or by varying the parameters or operation mode of the original mechanism so as to minimize the thermal losses in the driving motor. The solution is based on the minimization of the functional determining the irreversible power losses. We show that, for the engines considered, all cyclic mechanisms with one degree of freedom should satisfy a fundamental condition ensuring the minimum of losses. We consider two examples, one of which corresponds to actually existing mechanisms.

We consider the problem of control of motion of a many-legged statically stable locomotion machine ensuring the choice of a minimal-power motor. We show that the machine frame can be used as a kinetic energy recuperator, thus providing a significant decrease in the reactive power.

The issues around problem of increasing efficiency of walking machine motion have been discussed in this paper. Among them: ground or bearing cross-country ability, profile cross-country ability, maneuverability, the energy consumption.

The walking machines of ground practicability are under consideration. The methods of calculations of the dynamic movement characteristics have been elaborated. The real walking machine has been designed, produced and tested on the basis of proposed methods of calculations.

Multilegged statically stable walking machines of soil cross-country capability with propellers on the basis of cycle mechanisms are under consideration. The turn both of existing and elaborating walking machines moving on comparativelly flat surface with poor carrying ability was learned out. Methods of parameters calculations of the kinematic scheme and control system for the new elaborating walking machine providing stable motion has been developed.

Multilegged statically stable walking machines of ground practicability with gears on basis of cycle mechanisms are under consideration. The dynamics of walking machines moving on comparatively flat surface with poor carrying layer was learned out both theoretically and experimentally in environmental conditions. Variations of improving the kinematic characteristics of moving of supporting point of walking mechanism were proposed and analyzed.