Patents by Hassan Hussein Hariri
The present invention relates to a piezoelectric device (1) comprising: a flexible plate (2), at ... more The present invention relates to a piezoelectric device (1) comprising: a flexible plate (2), at least three unaligned piezoelectric transducers (3) attached onto a single surface of the plate (2), and a sinusoidal voltage generator (4) that generates sinusoidal voltage and is connected to at least one piezoelectric transducer (3) such as to generate a traveling wave in the flexible plate (2). The piezoelectric device (1) is characterized in that the flexible plate (2) supporting the at least three piezoelectric transducers (3) is mobile, the generated traveling wave being capable of moving the flexible plate (2).
Papers by Hassan Hussein Hariri
— In small mobile robots, decreasing the number of actuators is usually desirable to reduce the s... more — In small mobile robots, decreasing the number of actuators is usually desirable to reduce the size and weight of the robot, but it is usually at the expense of the robot's degree of freedom (DOF). This work presents the development and preliminary experimental testing of a novel Legged Piezoelectric Miniature Robot (LPMR) driven only by a single piezoelectric unimorph actuator and yet fully capable of being maneuvered to move forward, turn right, or turn left. The underactuated motion is achieved by exploiting the bending vibration modes disparity of the piezoelectric actuator at different driving frequencies and designing specific positions of the robot's legs to generate a differential-drive-like mechanism. The speed of the robot can be controlled through regulating the magnitude of the applied voltage. The proposed underactuated system is experimentally verified and a preliminary characterization of the LPMR in terms of its forward and turning speed versus applied voltage and payload is investigated and reported.
This paper presents the design and development of a new type of piezoelectric-driven robot, which... more This paper presents the design and development of a new type of piezoelectric-driven robot, which consists of a piezoelec-tric unimorph actuator integrated as part of the structure of a four-bar linkage to generate locomotion. The unimorph actuator replaces the input link of the four-bar linkage and motion is generated at the coupler link due to the actuator deflection. A dimensional synthesis approach is proposed for the design of four-bar linkage that amplifies the small displacement of the piezoelec-tric actuator at the coupler link. The robot consists of two such piezo-driven four-bar linkages and its gait cycle is described. The robot speed is derived through kinematic modelling and experimentally verified using a fabricated prototype. This result will be important for developing a motion planning control strategy for the robot locomotion, which will be part of future work.
—In this paper, we developed a kinematic model for a legged piezoelectric miniature robot driven ... more —In this paper, we developed a kinematic model for a legged piezoelectric miniature robot driven by standing wave. The robot consists of a piezoelectric bending actuator with rigidly attached legs. The kinematic model allows us to compute the velocity analytically so that the robot motion can be predicted. To construct the kinematic model, the behaviour of the robot at the contact instances with the ground during the up and down stages is studied. A prototype is fabricated so as to verify our kinematic model experimentally, measured using a motion capture system. The result shows that the measured speed was in close agreement with that as predicted by our model.
To ensure safety and comfort, the automotive industry employs sensors to monitor the vehicle dyna... more To ensure safety and comfort, the automotive industry employs sensors to monitor the vehicle dynamics, with growing interest in intelligent tires. This paper specifically presents the design and validation of a dynamic load sensor proposed for integration in tires to allow active control of noise inside the cabin of the car. The concept of using tire surface strain measurement is first experimentally investigated using a quarter-car test bench, through coherence evaluation between the vertical force injected at the wheel hub and the out-of-plane velocity field over the lateral surface of the tire, as measured using a scanning laser Doppler vibrometer (LDV). The tire sidewall deformations are found to correlate well with vertical road excitations, suggesting that strain measurement on the tires could a useful signal for noise control. Specifications are then established for a sensor to measure strain on the tire, leading to the design and fabrication of a Capacitive Strain Transducer (CST) using printed electrodes on a flexible substrate. A number of CSTs are bonded on the tire and characterized to determine optimal sensor locations. The coherence achieved between the CST measurements and the excitation force is compared with a reference Macro Fiber Composite (MFC) transducer. The CST shows promise for providing the reference signal required in feedforward algorithms for active noise and vibration control inside the car, since it shows good coherence with the force reference
— This paper describes the design and evaluation of a Legged Piezoelectric Miniature Robot (LPMR)... more — This paper describes the design and evaluation of a Legged Piezoelectric Miniature Robot (LPMR) propelled by standing wave locomotion where the vibrations of legs are similar to the bounding gait locomotion of animals. The LPMR comprises of one piezoelectric patch, a metal beam, two contact joints, two rigid legs and contains all necessary power electronics required for tether-less operation. Through analysis of the bending modes of vibrations and driving frequency, a forward and backward motion is achieved by choosing specific positions for the legs. At 100 V amplitude and without embedded mass, the LPMR with the weight of 6.27 g, the length of 50 mm, the width of 10 mm and the height of 1.5 mm achieves maximum linear speed of 246.5 mm/s for forward motion and 302 mm/s for backward motion. The LPMR is able to carry 100.8 g at a speed of 49.6 mm/s for forward motion and 87.9 mm/s for backward motion when applying 100 V amplitude. The LPMR has a blocking force of 12 mN for forward motion and 9.8 mN for backward motion at 100 V amplitude. An experimental characterization for the LPMR in terms of speed versus applied voltage, speed versus embedded mass and blocking force for different applied voltages is explored and evaluated in this study.
— In this paper, we will study the locomotion behaviour of a meso scale legged piezoelectric mobi... more — In this paper, we will study the locomotion behaviour of a meso scale legged piezoelectric mobile robot driven by standing wave. The design exploits the use of standing waves to be transmitted to its legs to propel the robot forward. A piezoelectric robot is designed and discussion are provided regarding the dynamic modelling of the mobile robot. An experimental measure of the speed according to the applied voltage is given herein on acrylic substrate. We have shown that 50 mm by 10 mm piezo actu-ator have demonstrated a bi-directional walking speed on acrylic substrate of up to 4 cm/s when a 40 V voltage is applied.
Curved and Layered Structures, 2014
The system studied in this paper consists of thin structure with several piezoelectric patches bo... more The system studied in this paper consists of thin structure with several piezoelectric patches bonded on its surface. The patches are used as actuators and sensors. Based on Kirchhoff-Love hypothesis, linear constitutive relations, plane stress formulation and Hamilton principle, we have developed a 2D model for this system using the finite element method. It is not a standard 2D model, since the calculation is performed on a structure that does not have symmetries that allow such easy assumptions. The originality of the work consists in the use of the concept of neutral plane to model this asymmetric system in 2D. This technique, beside good precision, saves computational time. An experimental device has been also built and tested to validate the model. The structural damping is included in the model to match the damping behavior of the real system. Optimizations of the thickness of piezoelectric patches and materials used in the thin structures are also presented in the paper.
ABSTRACT Inspired from linear traveling wave ultrasonic motors, a dual piezoelectric beam robot i... more ABSTRACT Inspired from linear traveling wave ultrasonic motors, a dual piezoelectric beam robot is presented. It consists of an aluminum beam structure, with two non-collocated piezoelectric patches bonded on its surface. The aim of this article is to study the effect of the piezoelectric patches’ positions on the performance of the robot. For a given robot dimension, a finite element model developed in a previous work for the robot structure is verified experimentally here and then used to determine the optimal piezoelectric patches’ position. It has been found that locating the piezoelectric patches near the ends of the beam will lead to best performance, and that the traveling wave is mainly generated between the two patches. Two prototypes have been manufactured for this aim and have shown good agreement with simulation results.
Smart Materials and Structures, 2014
ABSTRACT In this paper, the operation principles of a traveling wave piezoelectric beam robot are... more ABSTRACT In this paper, the operation principles of a traveling wave piezoelectric beam robot are presented. A prototype consisting of an aluminum beam structure, with two non-collocated piezoelectric patches bonded on its surface, was fabricated and tested to demonstrate the generation of a traveling wave on the beam based on the one mode excitation and the two mode excitation operation principles for propulsion. A numerical model was developed and used to study and optimize the generated motion of the piezoelectric beam robot. Experimental characterization of the robot for the two types of operation has been carried out, a comparison between them is made and results are given in this paper.
A new piezoelectric miniature robot design inspired from linear traveling wave ultrasonic motors ... more A new piezoelectric miniature robot design inspired from linear traveling wave ultrasonic motors is introduced and a comparison between the robot and some linear traveling wave ultrasonic motors is done. To model the robot, a finite element model based on Hamilton principle is developed. A prototype has been manufactured. The optimal operating frequency has been determinate using the model and validated experimentally. Then, to characterize the robot, we measured the robot speed on a smooth glass flat surface for different applied voltages and for different embedded masses. We measured also the robot speed as a function of the mechanical load at a given applied voltage, to determine the nominal operating point of the robot.
In this paper, the operation principle of a new type of piezoelectric miniature robot for terrest... more In this paper, the operation principle of a new type of piezoelectric miniature robot for terrestrial locomotion is
presented. A prototype consists of an aluminum beam structure, with two non-collocated piezoelectric patches
bonded on its surface was fabricated and tested to demonstrate the generation of a traveling wave based on a
two modes excitation on the beam for propulsion. A numerical model was developed and used to study and
optimize the generated motion of the robot. An experimental characterization of the robot has been done and
results are given in this paper.
Keywords: Piezoelectric miniature robot, terrestrial locomotion, a two modes excitation, modeling,
experimental characterization.
The system studied in this paper consists of a beam structure, with two non-collocated piezoelect... more The system studied in this paper consists of a beam structure, with two non-collocated piezoelectric patches attached to its surface. One patch produces the mechanical displacement of the beam by applying an electrical voltage, while the other converts this mechanical displacement into electrical energy which is then dissipated through passive electrical networks. By using the notion of neutral axis for this asymmetric system and Hamilton principle, a finite element model, incorporating the electrical dynamics of the connected passive electrical circuits is presented. Series and parallel RL circuits are considered here. Basing on the finite element model, an iterative method to determine optimum values of the RL circuits is studied; performance comparison between series and parallel RL circuits for vibration suppression is made
The system studied in this paper is a piezoelectric unimorph actuator. Considering the Love-Kirch... more The system studied in this paper is a piezoelectric unimorph actuator. Considering the Love-Kirchhoff hypothesis, the linear constitutive relations and the uniaxial stress, we have developed analytic and finite element models for the piezoelectric unimorph actuator in static and dynamic operation. In this analysis we have used the notion of neutral axis for asymmetric structure and Hamilton principle. Furthermore, the structural damping is included in the two models. To evaluate models, results are compared with 3D finite element software. After validation, the actuator design is studied for different passive layers including optimal thickness of the piezoelectric active layer and frequency for the unimorph piezoelectric actuator.
Piezoelectric miniature robots are mobiles robots with a size of a few cm3 actuated by piezoelect... more Piezoelectric miniature robots are mobiles robots with a size of a few cm3 actuated by piezoelectric materials. In this paper, we will study the locomotion principles for piezoelectric miniature robots. They are mostly inspired from the animal locomotion and are classified by their displacement through a fluid medium or on a solid substrate. We will discuss wheeled locomotion, walking locomotion, inchworm locomotion, inertial drive, resonant drive, and Friction drive as locomotion’s on a solid substrate. In liquid, locomotion for mobile miniature robots is totally inspired from animal locomotion and is divided into locomotion inside liquid and locomotion at the liquid surface. A brief description of animal locomotion in liquid is given. In air, locomotion for mobile miniature robots is divided into flapping wings, rotary wings, fixed wings and gliding wings. Flapping wings is the only method described in this paper. After definition of each locomotion principle, some piezoelectric m...
Http Www Theses Fr, Nov 28, 2012
The objective of this thesis is to design and realize a piezoelectric mobile for cooperative use.... more The objective of this thesis is to design and realize a piezoelectric mobile for cooperative use. The term piezoelectric mobile is used in this thesis to describe a piezoelectric miniature robot. This mobile miniature robot is actuated by piezoelectric materials. The aim of the thesis is the design and the realization of a robot that can be miniaturized and could therefore be used in the context of biological mimicry swarms (ants, bees ...) for a cooperative operation.The realized robot consists of a thin support and piezoelectric patches. Piezoelectric patches are bonded on the support on an intelligent manner in order to move the support on land. In this context, the thesis is divided into three parts.The first part is devoted to the modeling of such a system (thin support with piezoelectric patches on one of its faces). Modeling by the finite element method is developed for this system based on the variational principle of Hamilton and considering the Love-Kirchhoff hypothesis. The originality of this model lies in the use of the concept of the neutral plane to model this asymmetric system. This allows modeling the system studied by a finite element model in two dimensions (2D), taking into account the third dimension in the calculation.The second part presents the operating principle of the robot which is inspired by the linear traveling wave ultrasonic motors. This section presents all the stages of the optimal design to create the necessary movements. The optimal design is investigated using finite element modeling obtained in the first part.The third part of this thesis is devoted to the realization of an experimental prototype. The manufacturing process and the associated electronics for the robot are presented in this section. The robot is characterized experimentally by measuring the speed according to the applied voltage, the speed versus mass loaded by the robot and the speed according to the force provided by the robot. This robot is also compared with other similar systems.
Le système étudié dans le présent document est une structure constituée d’une plaque encastrée à ... more Le système étudié dans le présent document est une structure constituée d’une plaque encastrée à une extrémité munie de plusieurs patches piézoélectriques collés sur une même face. Les patches sont utilisés comme des actionneurs et de capteurs à la fois. Considérant l'hypothèse de Love-Kirchhoff, les relations linéaires constitutives, la formulation de contrainte plane et le principe d’Hamilton, nous avons développé un modèle élément fini 2D de la structure. L’objectif du travail présenté est de valider expérimentalement le modèle élément fini. L'amortissement structural est inclus dans le modèle élément fini pour tenir compte des pertes mécaniques. L’originalité du travail réside dans l’utilisation de la notion du plan neutre pour modéliser ce système asymétrique, ce qu’il le rend le premier article qui traite ce genre de problème dans la littérature. Cette technique permet de gagner du temps de calcul
Le système étudié dans le présent document est une structure constituée d’une poutre encastrée à ... more Le système étudié dans le présent document est une structure constituée d’une poutre encastrée à une extrémité munie de deux patchs piézoélectriques collés sur une même face. Considérant l'hypothèse d’Euler-Bernoulli, les relations linéaires constitutives, la contrainte uniaxiale et en appliquant le principe d’Hamilton, nous avons développé une modélisation simplifiée de la structure. Deux cas sont étudiés, dans le premier, un patche piézoélectrique est utilisé comme actionneur et l’autre comme capteur; dans le deuxième cas, les deux patchs sont utilisés comme actionneurs. L’objectif du travail présenté est de valider expérimentalement le modèle simplifié. L'amortissement structural est inclus dans le modèle pour tenir compte des pertes mécaniques. L’originalité du travail réside dans l’utilisation de la notion d’axe neutre pour modéliser ce système asymétrique. Cette technique permet de gagner du temps de calcul. La modélisation en incorporant la notion d’axe neutre peut se faire en utilisant la méthode des différences finies ou la méthode des éléments finis. Après validation expérimentale du modèle par éléments finis simplifié, une étape d’optimisation est présentée.
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Patents by Hassan Hussein Hariri
Papers by Hassan Hussein Hariri
presented. A prototype consists of an aluminum beam structure, with two non-collocated piezoelectric patches
bonded on its surface was fabricated and tested to demonstrate the generation of a traveling wave based on a
two modes excitation on the beam for propulsion. A numerical model was developed and used to study and
optimize the generated motion of the robot. An experimental characterization of the robot has been done and
results are given in this paper.
Keywords: Piezoelectric miniature robot, terrestrial locomotion, a two modes excitation, modeling,
experimental characterization.
presented. A prototype consists of an aluminum beam structure, with two non-collocated piezoelectric patches
bonded on its surface was fabricated and tested to demonstrate the generation of a traveling wave based on a
two modes excitation on the beam for propulsion. A numerical model was developed and used to study and
optimize the generated motion of the robot. An experimental characterization of the robot has been done and
results are given in this paper.
Keywords: Piezoelectric miniature robot, terrestrial locomotion, a two modes excitation, modeling,
experimental characterization.