Analysis of planned motion trajectories for scalable micro-robots

Prototypes of micro-robots and geometric path planning algorithms are presented in this paper. Geometric motion trajectories are generated by switching contacts, control points and tangents methods. Analysis of high-speed formation of trajectories using switching contacts method revealed that the geometric path depends on orientation angle of a micro-robot. Investigation of formation of high-precision trajectories demonstrated that there is minimal deviation from the given motion trajectory at which micro-robot stops. This paper presents methodologies for evaluation of optimal orientation angle of a micro-robot and minimum deflection from the given trajectory. The methodologies are verified by experiments

Research and development of piezoelectric active supports for precise shafts

Design and investigation of active piezoelectric block, having a precise V-shaped groove for checking the roundness or concentricity of precise shafts is presented. Piezoelectric V-block realizes the rotation and translational motion of the precise shaft and is characterized by zero base errors of motion generation system. Numerical modeling based on finite element method is performed to find resonant frequencies and modal shapes of the piezoelectric actuator. The trajectories of the contacting points for shaft – piezoelectric actuator is defined. Results of numerical and experimental studies are presented

Development of traveling wave actuators using waveguides of different geometrical forms

The paper covers the research and development of piezoelectric traveling wave actuators using different types of the waveguides. The introduced piezoelectric actuators can be characterized by specific areas of application, different resolution, and torque. All presented actuators are ultrasonic resonant devices and theywere developed to increase amplitudes of the travelingwave oscillations of the contact surface.Three different waveguides are introduced, that is, symmetrical, asymmetrical, and cone type waveguide. A piezoelectric ring with the sectioned electrodes is used to excite traveling wave oscillations for all actuators. Operating principle, electrode pattern, and excitation regimes of piezoelectric actuators are described. A numerical modelling of the actuators was performed to validate the operating principle and to calculate trajectories of the contact points motion. Prototype actuators were made and experimental study was performed.The results of numerical and experimental analysis are discussed

Analysis of planned motion trajectories for scalable micro-robots

Prototypes of micro-robots and geometric path planning algorithms are presented in this paper. Geometric motion trajectories are generated by switching contacts, control points and tangents methods. Analysis of high-speed formation of trajectories using switching contacts method revealed that the geometric path depends on orientation angle of a micro-robot. Investigation of formation of high-precision trajectories demonstrated that there is minimal deviation from the given motion trajectory at which micro-robot stops. This paper presents methodologies for evaluation of optimal orientation angle of a micro-robot and minimum deflection from the given trajectory. The methodologies are verified by experiments

Excitation of 2D resonant oscillations in piezoelectric plate with additional masses

This article presents results of investigation of piezoelectric transducer which consists of rectangle homogeneous piezoceramic plate with two additional masses glued on the top surface of the transducer. Because of additional masses and a certain sectioning of piezoelectric electrodes, the vibration forms of the plate and resonant frequencies are changed, therefore, the plate generates 3D longitudinal and bending vibrations. Numerical and experimental investigation showed that the masses glued at the surface of piezoelectric plate obtain elliptical trajectories of motion when the first mode of longitudinal vibrations of the plate is excited. Such form of vibrations of the masses enables using them for various piezoelectric drive mechanisms as contact elements and to transform high-frequency vibrations into the directional or rotational movement of the rotor or slider. In order to examine the deformations and dynamic characteristics of the homogenous piezoelectric plate with two additional masses, the numerical modelling of such piezo transducer and the experimental study have been carried out

Cylindrical piezorobot’s trajectory planning and control

This paper analyses the movement of piezoelectric actuator. The goal of this work was to create an algorithm for trajectory planning of piezorobot, create a system for trajectory control, develop software and verify the functioning of the algorithm in practice. Movements of piezorobot are very small and very frequent therefore it is difficult to measure trajectories using standard equipment. Design of a novel measurement system and trajectory adjustment was created in this paper. An experimental system for control and trajectory movement tracking of piezorobot was developed. It consists of cylindrical piezorobot, control signal forming and image processing system for trajectory tracking. The cylindrical piezorobot moves in specific trajectories on the plane and is controlled with sinusoidal signals. They are generated by trajectory forming and control software using MATLAB and LabVIEW. The control signals are monitored using a system with oscilloscope. The trajectory of piezorobot was monitored and measured using video camera and video processing software developed by LabVIEW. The software contains image processing and object path tracking, and is implemented using LabVEW and MATLAB. Experimental results showed that trajectories forming algorithm and developed control software is suitable for controlling robots moving on plane

Piezoelectric laser beam deflector for space applications

Optical beam deflectors are used to control direction of the optical beam therefore accuracy of the optical system strongly depends on dynamic characteristic of the deflector. Three degrees of freedom (3DOF) piezoelectric micro-actuator for optical beam deflector is investigated in the paper. Piezoelectric micro-actuator consists of piezoelectric cylinder and ferromagnetic hemisphere that contacts the cylinder in the three points. Electrodes of the outer surface of the cylinder are divided into three sections. Three harmonic electric signals are used for piezoelectric cylinder excitation. Numerical and experimental study was performed to analyse dynamic characteristics of the piezoelectric actuator. Results of the studies are compared and discussed

Excitation of 2D resonant oscillations in piezoelectric plate with additional masses

This article presents results of investigation of piezoelectric transducer which consists of rectangle homogeneous piezoceramic plate with two additional masses glued on the top surface of the transducer. Because of additional masses and a certain sectioning of piezoelectric electrodes, the vibration forms of the plate and resonant frequencies are changed, therefore, the plate generates 3D longitudinal and bending vibrations. Numerical and experimental investigation showed that the masses glued at the surface of piezoelectric plate obtain elliptical trajectories of motion when the first mode of longitudinal vibrations of the plate is excited. Such form of vibrations of the masses enables using them for various piezoelectric drive mechanisms as contact elements and to transform high-frequency vibrations into the directional or rotational movement of the rotor or slider. In order to examine the deformations and dynamic characteristics of the homogenous piezoelectric plate with two additional masses, the numerical modelling of such piezo transducer and the experimental study have been carried out

Piezoelectric laser beam deflector for space applications

Optical beam deflectors are used to control direction of the optical beam therefore accuracy of the optical system strongly depends on dynamic characteristic of the deflector. Three degrees of freedom (3DOF) piezoelectric micro-actuator for optical beam deflector is investigated in the paper. Piezoelectric micro-actuator consists of piezoelectric cylinder and ferromagnetic hemisphere that contacts the cylinder in the three points. Electrodes of the outer surface of the cylinder are divided into three sections. Three harmonic electric signals are used for piezoelectric cylinder excitation. Numerical and experimental study was performed to analyse dynamic characteristics of the piezoelectric actuator. Results of the studies are compared and discussed

Piezoelectric laser beam deflector for space applications

Optical beam deflectors are used to control direction of the optical beam therefore accuracy of the optical system strongly depends on dynamic characteristic of the deflector. Three degrees of freedom (3DOF) piezoelectric micro-actuator for optical beam deflector is investigated in the paper. Piezoelectric micro-actuator consists of piezoelectric cylinder and ferromagnetic hemisphere that contacts the cylinder in the three points. Electrodes of the outer surface of the cylinder are divided into three sections. Three harmonic electric signals are used for piezoelectric cylinder excitation. Numerical and experimental study was performed to analyse dynamic characteristics of the piezoelectric actuator. Results of the studies are compared and discussed