The reaction time, which is also referred as reflex delay in the literature, is an important factor in human balancing, since reaction time highly affects the ability of self stabilization. Increased reaction time delay may cause dangerous fall-over accidents related to elderly people. Reaction time depends on age, health, everyday activities, the general and actual physical and mental state of the individual and the environmental conditions.The reaction time is considered as a parameter in many of the mathematical models of the neural processes in human balancing. It is beneficial in many cases to estimate the reaction time based on experimental data.The present paper introduces the prototype of a complex reaction time tester instrument. The novelty of the instrument is that the reaction time can be measured in various combinations of sensory organs and reaction movements. The reaction time is defined as the time duration in between the initial time instant of the stimulus of the sensory organs (input signal) and the onset of the response that is typically indicated by a button or a pedal. Another novelty is that the instrument is free of any uncertain time delay, which is not the case for several instruments available.Usually, human simple reaction time is considered to be roughly about 200 ms. The shortest (aural) reaction time for skilled athletes is 85ms. In our measurements the shortest reaction time was 97 ms, and the mean about 190 ms in simple reaction cases. So our collected experimental data are in agreement with the literature.

Spatial pose estimation devices for mobile and cable-suspended robots have been rapidly developed. The HTC Vive sensor, which operates with swept laser beams, has aroused many researchers' interest. We present experiments with a double pendulum robot equipped with the HTC Vive Tracker. A linear feedback controller ensured the tracking of pre-defined end-effector trajectories of various speeds. The pose feedback of the controller was provided by the HTC Vive. As a reference, the realized trajectory was measured by the OptiTrack motion capture system. We report that the motion control of a spatial double pendulum robot can be achieved by using a linear feedback controller together with cable winch and fan actuators providing six independent inputs. The accuracy of the HTC Vive was proved to be sufficient for the feedback position control of indoor mobile robots. We report that the error strongly correlates with the linear/angular velocity, the acceleration and the jerk.

The paper presents the first results of an exploratory research work, aiming the experimental evaluation of the mechanical contact between conforming surfaces of metallic bodies. The proposed procedure—that is based on the measurement of electric potentials—is able to determine the actual contact pattern and estimate the force distribution on the opposing surfaces. In the present paper, the contact properties along a curve are evaluated, but the basic principles supporting the solution of the more general surface contact problem are also laid down. The goal of this research work is to provide a reliable basis for the investigation of contact-related effects on the modal properties of structures and machines. The distribution of electric contact resistivity can also be assessed using this method, opening the way to the refined characterization of electric switches and connectors. During the application of the method, measured electric voltage values are processed by a neural network trained on a data set generated by finite element software. The resulting electric contact conductivity distribution is used to determine the contact force distribution, taking into account the equilibrium of forces and moments. The results are also checked by available alternative experimental methods.

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