International Scientific Journals
of Scientific Technical Union of Mechanical Engineering "Industry 4.0"

Pneumatic artificial muscles (PAM) have many useful properties (low cost, high power to weight ratio, flexibility…), but present a challenge if we want to achieve accurate position control due to their nonlinear characteristics. In this paper we present the development of the new control algorithm for the accurate position control of two antagonistically coupled PAM’s. We tested the algorithm on an experimental setup (rotational one-DOF pneumatic actuator with two PAM’s) for measuring muscles’ response. Newly developed control algorithm is an upgraded A-PID (Adaptive PID) control algorithm (by M. Pipan), that was developed for a linear actuator with only one pneumatic artificial muscle. The final part of this paper contains the comparison of experimental results to two other similar systems.

This paper describes the development of a simulation model. The model deals with the role of assembly worker in the virtual environment with an emphasis on ergonomics and time analysis. Firstly, we analyse time reports of common tasks in manufacturing processes like reaching, lifting etc. We receive time reports from three different methods: analytical MTM method, Siemens JACK 8.4 simulation and practical experiment. Secondly, we look into influential parameters, dimensions and mass of object, which affect the time reports. The results of our research show us that the parameters have different weight of importance. The main goal of this paper is to propose suggestions and guidelines for a worker-friendly environment from an automated generated ergonomic report of JACK simulation. We also ergonomically evaluate the task of lifting with the NIOSH method and propose improvements.

Main purpose of the paper is to present high-response hydraulic linear drive, which is controlled with new digital piezo valve and where the new position transducer is integrated as a part of hydraulic cylinder. The new linear drive has great potential for the use in modern adaptive position control systems integrated into the smart machines. Hydraulic digital piezo valve with main static and dynamic characteristics as well as its functionality is presented in detail. The main static and dynamic characteristics of digital piezo valve which influence directly on the linear drive performance are high resolution of the volume flow rate and high response of the valve. Beside valve characteristics the new integrated position transducer, the digital controller and control method, presented in the paper, have major impact on linear drive performance. At the end of the paper the step response and position resolution of the hydraulic linear drive controlled with the new digital valve is shown and compared with the results of reference hydraulic drive controlled with high response proportional valve.