Kinematically-redundant manipulators present considerable difficulties, especially from the view of control. A high number of degrees of freedom are used to control so-called secondary tasks in order to optimize manipulator motion. This paper introduces a new algorithm for the control of kinematically-redundant manipulator considering three secondary tasks, namely a joint limit avoidance task, a kinematic singularities avoidance task, and an obstacle avoidance task. For path planning of end-effector from start to goal point, the potential field method is used. The final inverse kinematic model is designed by a Jacobian-based method considering weight matrices in order to prioritize particular tasks. Our approach is based on the flexible behavior of priority value due to the acceleration of numerical simulation. The results of the simulations show the advantage of our approach, which results in a significant decrease of computing time.

The field of continuum robotics is rapidly developing. The development of new kinematic structures, locomotion principles and control strategies is driving the development of new types of sensors and sensing methodologies. The sensing in continuum robots can be divided into shape perception and environment perception. The environment perception is focusing on sensing the interactions between the robot and environment. These sensors are often embedded on an outer layer of the robots, so the interactions can be detected. The shape perception is sensing the robot’s shape using various principles. There are three main groups of sensors that use the properties of electricity, magnetism and optics to measure the shape of the continuum robots. The sensors based on measuring the properties of electricity are often based on measuring the electrical resistance or capacitance of the flexible sensor. Sensors based on magnetism use properties of permanent magnets or coils that are attached to the robot. Their magnetic field, flux or other properties are then tracked, and shape reconstruction can be performed. The last group of sensors is mostly based on leveraging the properties of traveling light through optical fibers. There are multiple objectives of this work. Objective number one is to clearly categorize the sensors and make a clear distinction between them. Objective number two is to determine the trend and progress of the sensors used in continuum robotics. And finally, the third objective is to define the challenges that the researchers are currently facing. The challenges of sensing the shape or the interaction with the environment of continuum robots are currently in the miniaturization of existing sensors and the development of novel sensing methods.

The subject of this paper is the solution to specific problems in the measurement of the coefficient of the sliding friction of material pairs using a variable incidence tribometer. The aim of this work was to solve the questions of the measurement of the static coefficient of friction using a variable incidence tribometer from the perspective of metrology. In particular, we intended to research the expression of the credibility of this measurement and the possibility of increasing the credibility of the measurement. Another problem that needs to be solved is the method of carrying out the measurement, which has an impact on its achieved uncertainty. Sliding friction is a phenomenon that depends on many material properties such as contact area roughness, moisture, lubricants, temperature, and relative motion velocity. If environmental conditions are defined, the main input parameter is the relative motion velocity. For this input quantity, friction force becomes a symmetrical problem, and it is only necessary to explore this phenomenon for positive values of velocities. Symmetry in this area simplifies the research of this science topic.

Robotic football with humanoid robots is a multidisciplinary field connecting several scientific fields. A challenging task in the design of a humanoid robot for the AndroSot and HuroCup competitions is the realization of movement on the field. This study aims to determine a walking pattern for a humanoid robot with an impact on its dynamic stability and behavior. The design of the proposed technical concept depends on its stability management mechanism, walking speed and such factors as the chosen stability approaches. The humanoid robot and its versatility, along with the adaptability of the terrain, are somewhat limited due to the complexity of the walking principle and the control of the robot’s movement itself. The technical concept uses dynamic stability as the potential force of the inertial bodies and their parts so that the humanoid robot does not overturn. The total height of the robot according to the rules of the competition will be 50 cm. In the performed experiment, only the lower part of the humanoid robot with added weight was considered, which is more demanding due to the non-use of the upper limbs for stabilization. The performed experiment verified the correctness of the design, where the torso of the robot performed eight steps in inclinations of a roll angle +4/−2° and a pitch angle +4/−6°.

The paper deals with the proposed concept of a biped robot with vertical stabilization of the robot’s base and minimization of its sideways oscillations. This robot uses 6 actuators, which gives good preconditions for energy balance compared to purely articulated bipedal robots. In addition, the used linear actuator is self-locking, so no additional energy is required for braking or to keep it in a stable position. The direct and inverse kinematics problems are solved by means of a kinematic model of the robot. Furthermore, the task is aided by a solution for locomotion on an inclined plane. Special attention is focused on the position of the robot’s center of gravity and its stability in motion. The results of the simulation confirm that the proposed concept meets all expectations. This robot can be used as a mechatronic assistant or as a carrier for handling extensions.

This article deals with the modernization of an existing loading system for the analysis of elastic–plastic properties of sheet metals in plane stress. The identification of the beginning of plastic deformation of sheet metal in plane strain is important in the cold pressing of sheet metal and in the assessment of the load capacity of thin-walled structures in the automotive and aerospace industry. The design of the control structure of the hydraulic part of the loading system for cross testing was carried out to automatize the whole process of experimental evaluation. For this purpose, proportional pressure-reducing valves together with control electronics were designed. Thus, the loading system is a control system for which a control algorithm has been designed and implemented on a PC. A computer simulation was performed to verify the functionality of the load system. An FEM simulation was performed to verify the correctness of the proposed numerical models and to confirm the experimental results. A numerical nonlinear model of the selected material was applied for the specification of plastic deformations. From the results, it is possible to state the appropriateness of the used models as well as the appropriateness of using modernized equipment for subsequent analysis of the plastic deformation of cruciform specimens.