## On Transfer Functions Limitations to Active Vehicle Suspension

Mathematical Modeling, Vol. 7 (2023), Issue 1, pg(s) 18-22

It is often assumed that if practical difficulties are neglected, active suspension systems could produce in principle arbitrary ideal behavior. This paper presents the factorization approach that is taken to derive limitations of achievable frequency responses to active vehicle suspension systems in terms of invariant frequency points and restricted rate of decay at high frequencies. The factorization approach enables the determination of complete sets of such constraints on various transfer functions from the load and road disturbances for typical choices of measured outputs and then chooses the optimal vector of the measurements from the point of view of the widest class of the achievable frequency responses. Using a simple linear two-degree-of-freedom car suspension model, it will be shown that even using complete state feedback and in the case in which the system is controllable in the control theory sense, there are still limitations to suspension performance in the fully active state.

## Disturbance rejection in a one-half vehicle suspension using a fuzzy controller

Trans Motauto World, Vol. 7 (2022), Issue 3, pg(s) 98-102

Generally, passenger ride comfort can be interpreted as an attenuation of sprung mass acceleration or as peak minimization of sprung mass vertical displacement, while good handling can be characterized as an attenuation of unsprung mass acceleration. This effort devoted to passive suspension design is ineffective because improvements to ride comfort are achieved at the expense of handling and vice versa. Instead, the best result can be achieved by active suspension, i.e. when an additional force can act on the system and simultaneously improve both of these conflicting requirements. Another important goal of the control design is to maintain robustness of the closed loop system. In the paper, fuzzy logic is used to simulate active suspension control of a one-half-car model. Velocity and acceleration of the front and rear wheels and undercarriage velocity above the wheels are taken as input data of the fuzzy logic controller. Active forces improving vehicle driving, ride comfort, and handling properties are considered to be the controlled actuator outputs. The controller design is proposed to minimize chassis and wheels deflection when uneven road surfaces, pavement points, etc. are acting on tires of running cars. As a result, a comparison of an active suspension fuzzy control and a spring/damper passive suspension is shown using MATLAB simulations.

## Hydrometric monitoring of rivers and canals-technological innovations

The protection of soils and waters is an extremely important issue for humanity. The main task to be done by the scientific staff is to monitor and control the water quantities leaving the water management facilities. Measurements of kinematic quantities can be used not only for quantitative assessment of runoff, but also for verification of theoretically derived hydraulic dependency in different forms of water movement. They are the basis for experimental determination of a number of theoretically introduced coefficients measurement of the hydraulic quantities determining them. Hydro metric measurement of non-pressure currents is a specific activity that has gained wide application around the world. When determining the water quantities, observations of the river outflow are made, also the measured parameters can be used for other engineering tasks in the construction of hydro technical facilities.[1]

## Mobile antenna for underwater system for remote control “SOM_l”

Security & Future, Vol. 5 (2021), Issue 1, pg(s) 39-41

Mobile hydroacoustic antennas have been developed after theoretical optimization of their directivity characteristics. The directivity characteristics in the plane passing through their axis in radiation mode have been determined experimentally. A comparison is made between the calculated and experimentally obtained results for the orientation characteristics

## On electromagnetic actuator control in the active suspension systems

Trans Motauto World, Vol. 5 (2020), Issue 1, pg(s) 6-9

In the paper, the design of a linear motor as an actuator in vehicle active suspension systems will be presented. The attention is focused on several interesting design aspects of a non-traditional actuator (a linear synchronous permanent magnet motor with electronic commutation) controlled to obtain a variable mechanical force for a car active suspension. The main advantage of such a solution is the possibility to generate desired forces acting between the unsprung (wheel) and sprung (car body) masses of the car, providing good insulation of the car sprung mass from the road surface disturbances. In addition, under certain circumstances it is possible to reduce or even eliminate the demands concerning the external power source.

## Information-measuring system for monitoring the sanitary condition of tree stands

Industry 4.0, Vol. 5 (2020), Issue 3, pg(s) 142-147

The article presents the results of the development of an information-measuring system for monitoring the sanitary status of tree stands. The main purpose of such a system is to minimize the impact of the operator on the results of monitoring the sanitary status of tree stands by indirectly controlling the quality characteristics of the tree sap (by establishing the dependence of these characteristics on climatic factors) with the possibility of remote monitoring and control of the process of express control. The developed monitoring system allows to conduct a contactless (remote) survey of sensors, which are recorded in close proximity to the root system of selective trees from an array of tree plantations, and further, by mathematical treatment of climatic characteristics (acidity and salinity index, air temperature) zoning temperature health status. The system also allows you to predict the dynamics of extending the areas of tree planting. This enables those responsible for tree planting to take preventative measures to prevent such droughts. The main advantage of the developed information measurement system is its complete computerization, which eliminates a number of external subjective influences by the operator or the responsible person (necessity of visual inspection of the maximum number of trees in the array, erroneous perception of visual information, etc.). This, in turn, avoids systematic methodological errors, thereby improving the accuracy, speed and reliability of the monitoring and control results of this system.

## Energy control principles in an automotive active suspension system

Trans Motauto World, Vol. 4 (2019), Issue 3, pg(s) 107-110

In the paper, energy recuperation and management in automotive suspension systems with linear electric motors controlled using a proposed H∞ controller to obtain a variable mechanical force for a car damper is presented. Vehicle suspensions in which forces are generated in response to feedback signals by active elements obviously offer increased design flexibility compared to the conventional suspensions using passive elements such as springs and dampers. The main advantage of the proposed solution using a linear AC motor is the possibility to generate desired forces acting between the unsprung and sprung masses of the car, providing good insulation of the car sprung mass from the road surface disturbances. In addition, under certain circumstances using linear motors as actuators enables to transform mechanical energy of the vertical car vibrations to electrical energy, accumulate it, and use it when needed. Energy flow control (management) enables to reduce or even eliminate the demands concerning the external power source.

## Limitations to suspension performance in a two-degree-of-freedom car active suspension

Innovations, Vol. 7 (2019), Issue 3, pg(s) 111-114

It is often assumed that if practical difficulties are neglected, active systems could produce in principle arbitrary ideal behavior. This paper presents the factorization approach that is taken to derive limitations of achievable frequency responses for active vehicle suspension systems in terms of invariant frequency points and restricted rate of decay at high frequencies. The factorization approach enables us to determine complete sets of such constraints on various transfer functions from the load and road disturbance inputs for typical choices of measured outputs and then choose the “most advantageous” vector of the measurements from the point of view of the widest class of the achievable frequency responses. Using a simple linear two degree-of-freedom car suspension system model it will be shown that even using complete state feedback and in the case of in which the system is controllable in the control theory sense, there still are limitations to suspension performance in the fully active state.

• ## The problem of control of the viscous incompressible liquid motion through a pipeline system

Mathematical Modeling, Vol. 3 (2019), Issue 1, pg(s) 10-19

In this paper the solution to the inverse problem of hydrodynamics of the viscous incompressible liquid, moving through pipes of the circular cross-section without a free surface, is given. For a given mass flow at one of the outlets of the pipeline system, the required pressure at its inlet is determined. The numerical simulation of the change in liquid velocity in the pipeline system is carried out for the given pressure variation at the inlet of the system.

• ## Formation of an enterprise`s system of investment activity monitoring

Machines. Technologies. Materials., Vol. 13 (2019), Issue 3, pg(s) 140-143

It has been proposed to the main stages of controlling based on its business investment principles. The main features of certain types of business investment controlling have been given. An example of a priorities system of an enterprise net investment returns` controlled indicator has been formed. It has been proposed the key stages of the monitoring system` building regarding investment activity controlled indices`. Business investment activity monitoring system has been worked out.

• ## Application of electronic systems for control and navigation in agriculture

The agricultural machines become more and more complex and complicated systems aimed to produce cheaper and plenty of agricultural products. The modern farmers uses computer technology and equipment not only for monitoring and analysis of the financial results from his activity, but also for expert assessment of yields, state of soil, crops, animals, machinery, product parameters, climatic conditions. Being acquainted with the principles of operation, structure, parameters and modes of adjustment and work with such electronic systems is becoming an obligatory part of the training of agricultural production experts.

• ## Monitoring and control of cyber-physical systems – the backbone of Industry 4.0

Industry 4.0, Vol. 3 (2018), Issue 4, pg(s) 155-157

Monitoring and control of Cyber-Physical Systems (CPS) have many challenges related to the heterogeneous environment, the high degree of interaction between the components and the high requirements for functionality and scale. The paper presents an analysis of the state of the art in this area and proposes an approach for monitoring and control of CPS through the integration of the IEC-61499 based models for distributed control systems and the IEC-61512 standard providing domain specific models for design and control of batch production processes as well as the Signal- Interpreted Petri Nets used for the purpose of formal specification and verification of unit procedures. The approach is illustrated with an example of CPS for loading a batch tank and mixing of liquid flow.