The Development of an Optimally-Tuned PID Control for the Actuator of a Transport Robot

An optimally-tuned PID control for a transport robot actuator based on an induction motor was developed. Continuous-discrete and continuous mathematical models of the actuator were obtained. The parametric synthesis of PID controller on the basis of continuous and discrete actuator models were performed. Numerical simulations using SimInTech for the adaptive regulator taking into account the cargo weight (from empty to maximum loaded) were carried out. The scheme of automatic selection of actuator PID coefficients considering the cargo weight was proposed. The scheme of automatic selection of coefficients of PID regulator for an actuator with regard to the cargo weight was suggested. As a result of parametric synthesis of discrete PID control law optimum values of its amplification coefficients were determined. There was no overcontrol and the transient time, which satisfied the initial requirements for the optimization of the control algorithm by angular velocity.

ADJUSTMENT OF FUZZY ADAPTIVE REGULATOR OF COMPRESSOR UNIT FOR LIQUEFACTION OF NATURAL GAS

The main properties of the object are studied, as well as the methods by which new parameters can be found for the regulator of the compressor unit for liquefaction of natural gas. The main properties of the adaptive regulator itself are studied, as well as the method by which the work was performed is developed. A comparison was also made with other types of automatic control systems that can be used in this facility. The sequence of construction of the adaptive controller and its interaction with the object is studied. The initial results of the adaptive controller and their comparison with other automatic control systems are investigated. The general properties and rules of construction of the adaptive regulator, the basic subtleties at work with it are studied. New possibilities for regulation of the compressor installation for liquefaction of natural gas are fully considered and the basic rules concerning application of this adaptive regulator are deduced. A study of the effectiveness of the adaptive regulator for this object was conducted and conclusions were made on the work of the regulator and the effectiveness of its results. A special sequence of work was also developed for the construction of an adaptive controller and its application on site. In general, the basic rules for working with such a regulator and its application in a natural gas liquefaction plant are derived. The behavior of the plant is investigated and new settings for the regulation of the natural gas liquefaction plant are derived. The main types of regulation of this object are applied and new rules for finding settings for the main regulator of the compressor unit are derived. The work on comparison of already traditional types of regulation with the adaptive regulator is made and conclusions on application of this or that type of regulation of compressor installation comparing results of regulation are made. The possibility of real use of this regulator on a constant basis in production is investigated, conclusions on the main work of the regulator and also shortcomings which can arise at a choice of regulation with the adaptive regulator are made.

Active vibration control development in ultra‐precision machining

This study presents a combined feedback–feedforward adaptive regulator applied to an active vibration control tool holder platform to contain the effect of machining vibrations. The proposed mechatronic solution can be integrated in a milling machine tool as an interface between the beam ( Z-axis) and the tool holder. The aim is to counteract vibrations in the broadband frequency range (100 Hz–900 Hz), controlling the tool position in real time. The active vibration control system is based on the harmonic steady-state concept due to the sinusoidal representation of the disturbance signals. The study focuses on the regulator architecture and the main logics applied to satisfy the required performance. A full investigation is executed through simulations and experimental campaigns, proving the disturbance reduction. The active vibration control system is implemented on a 4-axis machine tool and validated using multitonal disturbances. The system is evaluated in compensating a set of undesired effects, such as vibrations generated by unbalanced tools or hard material cutting processes. The obtained results show a maximum reduction of the vibration amplitude by 43.7% at the critical frequency.