Approach to the analysis of nonlinear dynamic systems structural identifiability (SI) under uncertainty is proposed. This approach has difference from methods applied to SI estimation of dynamic systems in the parametrical space. Structural identifiability is interpreted as of the structural identification possibility a system nonlinear part. We show that the input should synchronize the system for the SI problem solution. The S-synchronizability concept of a system is introduced. An unsynchronized input gives an insignificant framework which does not guarantee the structural identification problem solution. It results in structural not identifiability of a system. The subset of the synchronizing inputs on which systems are indiscernible is selected. The structural identifiability estimation method is based on the analysis of framework special class. The structural identifiability estimation method is proposed for systems with symmetric nonlinearities. The input parameter effect is studied on the possibility of the system SI estimation. It is showed that requirements of an excitation constancy to an input in adaptive systems and SI systems differ.

Progress of minimally invasive surgery stimulates the development of sensory techniques. The present study is related with creation of a mechatronic clamping laparoscopic device (forceps) that allows transferring tactile sensations from the jaws of the clamp to the handles of the master manipulator operated by surgeon. The user presses the handles of the manipulator. The change in the angle between the handles is synchronized with the change in the angle between the jaws of the forceps (slave link) that grasps the soft tissue. The contact load is identified based on the voltage applied to the electric motor connected to the forceps and then transferred to the control unit. This control unit adjusts the operating frequency of the piezoelectric actuator in such a way as to generate a force corresponding to the measured load. This force is applied to handles of the manipulator. It creates a moment in the handle, which is felt by the user. Thus, the system provides the tactile feedback. In order to describe the dynamics of the piezoelectric actuator, a finite-dimensional empirical model is used. In order to describe the dependence of the moment, with which the soft tissue acts upon the jaws of forceps, on the span angle between the forceps, a mathematical model is proposed. This model takes into account the properties of the soft tissue (which is assumed elastic) and geometry of the surface of forceps jaws. An algorithm for identification of the moment acting from the tissue on the forceps is proposed. Numerical simulation of dynamics of the system is performed. The results of calculations confirm the efficiency of the algorithm for identifying the moment created by tissue.

An algorithm of adaptive estimation of the magnetic flux for the non-salient permanent magnet synchronous motor (PMSM) for the case when measurable electrical signals are corrupted by a constant offset is presented. A new nonlinear parameterization of the electric drive model based on dynamical regressor extension and mixing (DREM) procedure is proposed. Due to this parameterization the problem of flux estimation is translated to the auxiliary task of identification of unknown constant parameters related to measurement errors. It is proved that the flux observer provides global exponential convergence of estimation errors to zero if the corresponding regression function satisfies the persistent excitation condition. Also, the observer provides global asymptotic convergence if the regression function is square integrable. In comparison with known analogues this paper gives a constructive way of the flux reconstruction for a nonsalient PMSM with guaranteed performance (monotonicity, convergence rate regulation) and, from other hand, a straightforwardly easy implementation of the proposed observer to embedded systems.

The parametric structural schemes, structural-the parametric models and the transfer functions of the electroelastic actuators for the nanomechatronics systems are obtained. The transfer functions of the piezoactuator are determined under the generalized piezoelectric effect. The changes in the elastic compliance and the stiffness of the piezoactuator are found, taking into account the type of control. The decision wave equation and the structural-parametric models of the electroelastic actuators are obtained. Effects of the geometric and physical parameters of the electroelastic actuators and the external load on its static and dynamic characteristics are determined. The parameteric structural schemes for the electroelastic actuators for the nanomechatronics systems are obtained. The transfer functions are determined. For calculation of the automatic control systems for the nanometric movements with the electroelastic actuators are obtained the parametric structural schemes and the transfer functions of actuators. Static and dynamic characteristics of the electroelastic actuators are determined. The application of electroelastic actuators solves problems of the precise matching in microelectronics and nanotechnology, compensation of temperature and gravitational deformations, atmospheric turbulence by wave front correction. By solving the wave equation with allowance for the corresponding equations of the piezoelectric effect, the boundary conditions on loaded working surfaces of the electroelastic actuator, the strains along the coordinate axes, it is possible to construct the structural parametric model of the actuator. The transfer functions and the parametric structural schemes of the electroelastic actuator are obtained from the equations describing the corresponding structural parametric models and taking into account the opposed electromotive force of the electroelastic actuator for the nanomechatronics systems.

The motion of a wind powered land boat is studied. It is supposed that the land boat moves along a straight line in a steady horizontal wind flow. The axis of rotation of the Savonius rotor is vertical. The rotation of the Savonius rotors induces the Magnus force that maintains the motion of the load boat. Such vehicles can be used to perform transportation in large open areas, where there is an access to free wind. In this paper, the mathematical model of the land boat driven by the Savonius rotor is constructed. The quasi-steady approach is used to describe the aerodynamic action upon the system. Corresponding aerodynamic coefficients are approximated basing on experimental data. The angle between the wind velocity and the velocity of the boat is a varied parameter of the model. The equations of the model are presented as a dynamic system of the second order. The conditions of existence and stability of stationary modes of the dynamic system motion are obtained. It is described how the boat speed at steady motion depends upon the angle formed by the velocity of the boat and direction of the wind. In particular, it is shown that the maximum of the boat speed is achieved on the close-hauled course, that corresponds to the recommendations of the sail settings known in sea navigation.

The work studies the flight phase (a part of jumping motion) of a jumping robot. The robot consists of the body with wheeled base and a jump booster module installed in the body. The jump booster module allows the robot to accelerate in a given direction up to a predetermined speed, allowing to control the velocity of the robot at the moment when it breaks contact with the supporting surface. The goal of this study is to develop a control system for the robot’s wheels, allowing to use their inertial properties to control the robot orientation at the moment of landing. This is achieved by controlling the wheels’ orientation throughout the duration of the motion. The goal of controlling the orientation of the robot at the moment of landing is to be able to land on all four wheels and avoid tipping over. The paper studies the supporting surfaces (from which the robot jumps and to which the robot lands) described by piecewise linear functions, including a horizontal and slopped linear sub-functions. In this work, four types of supporting surfaces were distinguished, which the distinction based on the slope of the mentioned about sub-function. Another varying parameter is the point where two sub-functions connect. For the purpose of this study a kinematic and dynamic model of the robot were developed, and a control system design was proposed. The proposed control system includes a trajectory planner that allows to plan the robot’s motion resulting in the desired orientation of the robot’s body at the moment of landing. This problem was formulated as an optimization problem. Simulation results showed the dependencies between the three supporting surface parameters (two angles describing linear sub-functions and the point where the sub-functions intersect) and the duration of the robot flight, the achieved velocities of the robot’s wheels and required motor torques. The influence of those parameters on the maximal and minimal values of the wheels’ angular velocities achieved during the flight were demonstrated. This could be used in designing this type of robots, in particular it could help to set specifications for the robot’s wheel motors.

In this article it is described the operation principle of a robotic manipulator ARMino device and the connection diagram of its electrical components. The device includes: An Arduino Mega control board, four servos, four potentiometers, a prototyping board, a computer. Turning the shafts on the potentiometer adjusts the position of the servo spindles. When the voltage on the potentiometer’s pin changes, the voltage at the analog inputs of the microcontroller changes. Then, in the microcontroller, the voltage is scaled to the value of the servo rotation angle. After that, the joints of the robotic manipulator are rotated. During the operation of the ARMino robotiс arm, a contact bounce problem appeared, significantly reducing the accuracy of positioning and the smooth movement of the ARMino joints. To solve this problem, a digital filter was developed. This article describes the digital filter working algorithm, which consists of four steps. One of the steps consists on finding the digital filter coefficients, which regulate the signal voltage level transmitted to the servo motors, and its transition process time which forms the signal edge. The main problem developing a digital filter is that the standard procedure of finding the digital filter coefficients, the coefficients are given by a recommended range of values, which complicates choosing from this range, a single value and transmitting it to the servos. To solve this problem, a fuzzy digital filter was developed, the algorithm of which consists of six steps. The first step determines the input variables degree of truth. The second step is to calculate the degrees of truth of the fuzzy rules preconditions. The third step is to calculate the degrees of truth of the fuzzy rules conclusions by using the process of finding the maximum values. The fourth step is the defuzzification stage in which a precise value of the fuzzy digital filter coefficient is calculated. The fifth step is the output voltage transmitted to the servos. In the sixth step, the output voltage in the microcontroller is converted to the angle value and the servo is given the command to rotate. This article presents numerical simulation of the fuzzy digital filter algorithm, using as an example the servo responsible of the ARMino base rotation. Experimental studies on the functioning of the fuzzy digital filter have been carried out, confirming the expediency of its use. The graphics of the transition process of the robotic manipulator base movement without and with the use of a digital filter are given.

Several various missile homing systems (MHS) have been developed in recent years. However, to the best of our knowledge, these systems do not take into account the dynamic characteristics of the measurement elements (ME). Such existing systems can only work well when the MEs have a small inertia and large damping. Thus in general case, it is necessary to consider the dynamic characteristics of the MEs with the big inertia. In addition, using the MEs with the big inertia, the MHSs is able to remove the high-frequency noise. However, taking into account the dynamic properties of the MEs causes difficulties in determining the transfer function (PF) of the normal acceleration stability system and the synthesis of MHSs. Therefore, in this paper, we propose an effective mathematical model of the missile homing system, which takes into consideration the dynamic characteristics of the MEs. In addition, this model allows synthesizing the high accuracy MHSs, and utilizing the MEs with the inertia equivalent to the inertia of the rudder actuator. To accomplish that, the proposed system is composed of two stages. In the first stage, the MHSs, which do not incorporate the dynamic characteristics of the MEs, is presented in detail. Then, we analyze and estimate the effect of the dynamic characteristics of the MEs on the performance of the MHSs. In the second stage, we propose a novel MHS, which takes into account the dynamic characteristics of the MEs. The proposed system is implemented based on the basic functions in the Control system toolbox in MATLAB, and designed by the parametric optimization method. The simulation results indicate that, our proposed system outperforms the conventional MHSs in term of reducing the negative effects of the dynamic characteristic of the MEs on the quality of the MHS.