No abstract

In this paper semi-active control of the suspension of an all-terrain vehicle is considered. A seven degree of freedom suspension model is presented first. A fuzzy approach for controller synthesis is then proposed. Expert knowledge is stored in the form of IF-THEN rules. The Takagi-Sugeno inference system is employed, with triangle membership functions. The fuzzy system output is the damper coefficient. In contrary to many other control algorithms, the presented fuzzy algorithm does not require inverse modelling of the magnetorheological damper. Instead, some scaling parameters are set. They can be chosen experimentally, or a bio-inspired strategy can be applied. The fuzzy control is then compared with the Skyhook control in simulations, in terms of road holding and driving comfort indicators. Obtained results are similar. However, lack of necessity to use an MR inverse model allows the fuzzy system to provide successful performance in case of different operating conditions, what is an important benefit.

Abstract:Comparison of dry and wet grinding process in an electromagnetic mill is presented in this paper. The research was conducted in a batch copper ore grinding. Batch mode allows for precise parametrization and constant repetitive conditions of the experiments. The following key aspects were tested: processing time, feed size, size of the grinding media, mass of the material and graining media, and density of the pulp. The particles size distribution of the product samples was analyzed in the laboratory after each experiment. The paper discusses the experimental results as well as the concept of dry and wet grinding and classification circuits for the electromagnetic mill. The main points of the discussion are the size reduction effectiveness and power consumption of the entire system.

In this article, multiple input-multiple output adaptive feedback control techniques for acoustic noise control in a headrest system are developed. The main goal underlying their design is to provide acoustic comfort to the user, i.e. high noise attenuation level over possibly large areas at the ears. Classical Internal Model Control system does not yield acceptable performance. An approach based on estimates of the residual noise at the ears is then proposed. It is shown that increase in the number of secondary sources to operate for one channel improves the performance. The experiments of tonal noise control are performed on an originally set-up prototype of the active headrest system. The results obtained are illustrated in the promoted form of distribution of zones of quiet.

The paper presents an innovative construction and installation of dry grinding in electromagnetic mill that provides a significant reduction of energy consumption when compared to traditional mills. The installation constitutes complex multi-objective plant. To gain control over all the objectives, hierarchical structure of control system was developed where different time-horizons involve multi-rate scheme of steering. The paper presents solutions for the direct regulation, supervisory control, and optimization level. The electromagnetic mill installation constitutes a unique setup that causes open loop instability and implies the application of novel control schemes at all of the levels. The paper presents these solutions and illustrates them with the results of experiments carried out on the electromagnetic mill installations.