Magnetic Ball Research Articles

Teenage Curiosity: Magnetic Attraction Gone Wrong

A 13-year-old male presented with suprapubic pain, hesitancy, and dysuria beginning seven hours prior to arrival. After initial evasiveness, the patient admitted to inserting small, magnetic ball bearings into his penis. Vital signs and physical exam were unremarkable aside from mild suprapubic tenderness to palpation. Pelvic radiograph demonstrated about 45 radiopaque beads within the urethra and bladder. While urethral foreign body (FB) is an uncommon diagnosis, it is essential to identify quickly as lifelong complications can arise. Magnetic FBs are particularly concerning due to possible ischemia from compression injury and difficulty of removal. Safety concerns led to temporary market removal of neodymium magnetic toys, but sales resumed in 2016.

Improving the Intelligent Control of Magnetic Levitiation Ball Using Artificial Neural Network

Forecasting the time series behavior of magnetic levitation system has been a major research objective for the last five decades. This is due to the challenges presented as a result of its dynamic nature in motion. Initially this problem was supposed to be solves by control engineering researchers using predictive control modeling. However, due to the robust nature of the technological application (high speed train, maglev ball, e.t.c), precision in the control system has been a major challenge according to Earnshaw’s theorem. This paper improves intelligent control of a magnetic levitation (ball) system using artificial neural network. First the maglev system plant is identified and then a Neuro controller is designed to predict the dynamic behavior of this system using feedback linearization process. The system will be design and simulated using neural network tool and Mathlab.

Thermoelectric properties of BiSbTe/graphene nanocomposites

In this work, BiSbTe based graphene composites with different vol% of graphene were processed by the pressure assisted high frequency induction heated sintering. The exfoliated graphene was uniformly dispersed in the BiSbTe powder through magnetic stirring and ball milling. The pristine BiSbTe and composites powders were consolidated by the high frequency induction heated sintering. Thermoelectric properties of the developed bulks were investigated in the temperature range 300–500 K. The results suggest that ball milling as well as incorporation of graphene substantially changes the transport properties of nanostructured BiSbTe composites from pristine bulk. The electrical conductivity of the composites degraded somewhat gradually with the addition of graphene. The effective thermal conductivity reduces by incorporation of graphene, which is attributed to increased phonon scattering by the enormous nanostructured phase boundaries and graphene. The enhanced Seebeck coefficient accompanied by the reduction in thermal conductivity leads to improved figure of merit up to ~ 1.2 at ~ 375 K for 0.5 vol% graphene/BiSbTe composite.

Incremental SMC-based CNF control strategy considering magnetic ball suspension and inverted pendulum systems through cuckoo search-genetic optimization algorithm

A kind of incremental sliding mode control (SMC) approach in connection with the well-known composite nonlinear feedback (CNF) control strategy is newly considered in this research to deal with the nonlinear magnetic ball suspension and inverted pendulum systems, as well. The incremental SMC approach is in fact proposed to handle the aforementioned underactuated systems under control, which have a lower number of actuators than degrees of freedom. Based on the outcomes of the investigation presented here, the small overshoot and short settling time of the system response are fulfilled. In fact, the proposed CNF control strategy comprises two parts: the first term assures the stability of the closed-loop nonlinear system and provides a fast convergence response. The second term reduces its overshoot. The genetic-cuckoo hybrid algorithm is designed to minimize tracking errors for the purpose of finding the most suitable sliding surface coefficients. Finally, the finite time stability for the closed-loop system is proved, theoretically.

Design of Fuzzy Controller rule base using Bat Algorithm

The work in this paper revolves fundamentally around the main axes of fuzzy control of the type Takagi-Sugeno (T-S) zero order for dynamic, complex nonlinear systems. In this paper, we present method for designing Fuzzy controller rule base using a new swarm intelligence algorithm, which is based on the Bat algorithm. The Bat algorithm is one of the most recent swarm intelligence based algorithms that simulates the intelligent hunting behavior of the bats found in nature. The main objective is to design the fuzzy rule base of fuzzy controller respecting the desired performance. To demonstrate the efficiency of the suggested approach, a control of a Magnetic Ball Suspension System is selected. Simulation results shows that the proposed approach could be employed as a simple and effective optimization method for achieving optimum determination of fuzzy rule base parameters.

Levitation of Conductive and Magnetically Anisotropic Ball

This paper presents the analytical solution of levitation problem for both magnetically anisotropic and conductive balls. The magnetic field exerts eddy currents in magnetic and conductive balls. The forces, both Lorentz (of eddy current) and material (caused by inhomogeneity of reluctivity), lead to the levitation of the ball. The electromagnetic field is determined by means of variable separation method. The forces, both Lorentz and material acting upon the ball, are calculated. Power losses are calculated twice by means of Joule volume integral and Poynting surface integral. The total force is evaluated three times by Maxwell, coenergy, and Lorentz methods. Levitation force and power losses versus frequency are presented. Asymptotic relations for levitation force and power losses are derived. The comparison to levitating disk at the same volume is presented.

Two-dimensional triboelectric-electromagnetic hybrid nanogenerator for wave energy harvesting

The earth has abundant water resources, and efficient harvesting of energy from waves is always a research hotspot. In this paper, we fabricate a box-like triboelectric-electromagnetic hybrid nanogenerator for harvesting water wave energy, which is composed of the triboelectric nanogenerator (TENG) and the electromagnetic generator (EMG). In the case of TENG, the contact and separation between the aluminum film-coated PMMA cylinder and the silicone film covered interdigitated Ag electrodes is formed by ocean waves. In the case of EMG, a rolling magnetic ball is placed on the four coils to generate magnetic flux changes, thus generating electricity. Several experiments are conducted to validate the availability. Experimental results show that the instantaneous maximum output power of TENG is 0.08 mW at a load of 100 MΩ, and the instantaneous maximum output power of EMG is 14.9 mW at a load of 1 kΩ. The hybrid nanogenerator can light up 60 LEDs at the same time. After storing energy in the capacitor, the output DC signal can provide a continuous energy supply with the temperature sensor. More important, the nanogenerator can power the wireless acoustic sensing system.

3-D magnetic graphene balls as sorbents for cleaning oil spills

A 3-D magnetic graphene ball (MGB) material was prepared using cellulose as the carbon source. Carbon-encapsulated iron nanoparticles (CEINs) were first prepared by hydrothermal carbonization of cellulose powder at 180°C. Then, the prepared CEINs were catalytically graphitized to graphene-encapsulated iron nanoparticles (GEINs) at 900°C. Finally, GEINs were treated in carbon dioxide at 700°C, during which the iron core was oxidized to magnetite (Fe3O4) nanoparticles, and graphene shells were peeled off from the iron cores to form graphene nanoplatelets. The graphene nanoplatelets consist of 1–10 layers graphene with the in-plane size of 20–30 nm. The prepared 3-D MGB was investigated for the removal of oil from water, which demonstrated outstanding adsorption performance and excellent recyclability.

Single-axis driven measurement method to identify position-dependent geometric errors of a rotary table using double ball bar

With the development of error compensation technology, reliability and stability of error identification deserve much attention. And rotary axis errors of five-axis machine tool are the main error sources which result in machining inaccuracy. Hence, a new method for position-dependent geometric error (PDGE) identification of a rotary table using double ball bar was proposed in this paper. Especially, only the targeted rotary table was driven during the ball bar test, which can reduce the impact of interference error sources. During the measurement, the ball on the spindle holds still, and the ball on the rotary table rotates around the rotation axis. There are three mounting positions of magnetic socket on the rotary table. Total six measurement procedures of cone test are executed to obtain enough measuring results by setting different positions of magnetic socket ball. These measuring results are used to construct the identification model based on homogeneous transformation matrix (HTM). The impact of installation errors of the double ball bar on identified results was analyzed. The uncertainty of identified errors could be reduced with the single-axis driven and the installation parameter optimization. At last, testing experiments on a five-axis machine tool were conducted to verify the proposed method. The results confirm that the method is an effective way to identify PDGEs of a rotary axis, and the accuracy of identified results is improved.

Output control design and separation principle for a class of port‐Hamiltonian systems

SummaryUsing a structure preserving observer, a dynamic output controller is proposed for a class of port‐Hamiltonian systems. The core of this method is based on the notion of contractive port‐Hamiltonian systems. The proposed method utilizes an extended form of IDA‐PBC (interconnection and damping assignment passivity‐based control), a well‐known controller design method for port‐Hamiltonian systems and paves the way for using IDA‐PBC in output control design of challenging control objectives, such as output tracking for underactuated mechanical systems. In the line of output control design, a useful separation principle for a class of port‐Hamiltonian systems is achieved, which is valuable in the field of nonlinear systems. Some simulations on magnetic levitation and ball on wheel testbeds show the potency and applicability of the proposed method.

The effects of machining strategies of magnetic assisted roller burnishing on the resulted surface structure

The aim of this paper is to investigate the effect of different burnishing strategy on a C45 steel machining. Burnishing is a well-known, cold working surface improving technology, it is usually applied for cylindrical workpiece. In the reported research a novel developed magnetic assisted ball burnishing (MABB) tool was applied which was designed for MABB machining of flat and harmonic surfaces. To increase its efficiency, different types of machining strategies were applied. After the burnishing process the machined surfaces were measured by surface roughness tester to determine the most important Rsk and Rku tribological parameters. According to the results it can be stated that all different burnishing strategies have special application areas where they can be used efficiently (e.g. sliding surface, moulding tool and after- or pre-machining for ultra-precision machining).

On disturbance rejection in magnetic levitation

Magnetic levitation systems belong to an important and challenging class of control engineering problems with nonlinear uncertain dynamics, multiple disturbances and large sensor noise. To obtain a simple and practical solution that does not depends on the exact model information, a time-varying active disturbance rejection solution is proposed and validated in both numerical and experimental results. The proposed method is confirmed with rigorous analysis of transient performance and noise attenuation. Moreover, the proposed solution is tested in a magnetic levitation ball system with disturbances and measurement noise. The results show that the proposed solution is effective and practical.

A fully enclosed, 3D printed, hybridized nanogenerator with flexible flux concentrator for harvesting diverse human biomechanical energy

Human body motion is highly regarded as a promising source of energy for powering body-worn electronic devices and health monitoring sensors. Transforming the human biomechanical energy into an electrical energy provides a sustainable energy to drive those devices and sensors, reducing their battery dependency. This work presents a fully-enclosed wrist-wearable hybridized electromagnetic-triboelectric nanogenerator (FEHN) for effectively scavenging energy from the low-frequency natural human wrist-motion (≤ 5 Hz). The FEHN incorporates the rolling electrostatic induction and electromagnetic induction using a freely moving magnetic ball inside a hollow circular tube. The materials used in 3D printing technology are used as energy harvesting material for easy, quick and worthwhile fabrication of the FEHN. A thin flexible flux concentrating material is introduced to increase the emf and enhances the electromagnetic output performance. The FEHN can harvest energy under the diverse circumstances and irregular wrist-motions, such as swinging, waving, shaking, etc. Following the experiments, the FEHN achieves an average power density of 0.118 mW cm−3 and can drive a commercial wrist-watch continuously for more than 23 min from just 5 s of wrist motion. This successful demonstration renders an effective approach for scavenging wasted biomechanical energy and provides a promising solution towards the development of sustainable power supply for wearable electronic devices and self-powered healthcare monitoring sensors.

A human locomotion driven hybrid energy harvester for wrist wearable applications

In this work, a human locomotion driven hybrid energy generator has been proposed and experimentally validated for scavenging significant biomechanical energy from natural motion of arm swinging, to be used for wrist-wearable smart device applications. A proposed hybrid electromagnetic (EM) and triboelectric (TE) generator can deliver much higher output power than that of the individual harvesting device unit due to the combinational operation of EM and TE mechanisms under the same applied mechanical movements. A novel curved structural design based energy harvester is proposed from the comparative analysis of human hand swinging motion with double pendulum motion, which helps to enhance the output performance and design it fit to wear on wrist. The swinging of human arm during walking and running initiates a freely movable magnetic metal ball to oscillate inside the curved structure through both EM and TE part. The EM part consists of two coils wrapped around the curved body, one at each end and micro-structured Polydimethylsiloxane (PDMS) film is attached on the inner wall of curved body along with copper electrode for TE part. A prototype of the hybrid harvester has been fabricated and tested. The EM and TE devices are capable of delivering maximum 84.37mW peak power at 49.2Ω matching load resistance and 1.86μW peak power at 10MΩ load resistance respectively which are considerably higher than the trending state-of-the-art devices.

A Ball-Impact Piezoelectric Converter Wrapped by Copper Coils

This letter presents a composite piezoelectric and electromagnetic converter with a ball-impact structure. It is composed of a magnet ball enclosed among two piezoelectric diaphragms, which arranged in a copper coils wrapped cube. A theoretical model is proposed to simplify the motion of the ball in a cycle as three steps and to estimate output voltages. Experiments were conducted to measure output voltages of both piezoelectric and electromagnetic units. The observed experimental results are in good agreement with the theoretical ones.

CDM Based Servo State Feedback Controller with Feedback Linearization for Magnetic Levitation Ball System

This paper explains the design of Servo State Feedback Controller and Feedback Linearization for Magnetic Levitation Ball System (MLBS). The system uses feedback linearization to change the nonlinear model of magnetic levitation ball system to the linear system. Servo state feedback controller controls the position of the ball. An integrator eliminates the steady state error in servo state feedback controller. The parameter of integral gain and state feedback gains is achieved from the concept of Coefficient Diagram Method (CDM). The CDM requires the controllable canonical form, because of that Matrix Transformation is needed. Hence, feedback linearization is applied first to the MLBS then converted to a controllable form by a transformation matrix. The simulation shows the system can follow the desired position and robust from the position disturbance. The uncertainty parameter of mass, inductance, and resistance of MLBS also being investigated in the simulation. Comparing CDM with another method such as Linear Quadratic Regulator (LQR) and Pole Placement, CDM can give better response, that is no overshoot but a quite fast response. The main advantage of CDM is it has a standard parameter to obtain controller’s parameter hence it can avoid trial and error.

Adaptive TOPSIS fuzzy CMAC back-stepping control system design for nonlinear systems

This paper aims to propose a more efficient control algorithm for nonlinear systems. A novel adaptive Technique for Order of Preference by Similarity to Ideal Solution (TOPSIS) fuzzy cerebellar model articulation controller (FCMAC) back-stepping control system is developed. The proposed adaptive TOPSIS FCMAC (ATFCMAC) incorporates a multi-criteria decision analysis with a fuzzy CMAC structure to determine the optimal threshold values for selecting suitable firing nodes, improving the computational efficiency, reducing the number of firing rules, and achieving good performance for nonlinear systems. A back-stepping technique is employed for the control system design. The proposed control system comprises an ATFCMAC and a robust compensator; the ATFCMAC is used to approximate an ideal controller and the robust compensator is used to reduce the influence of residual approximation error between the ideal controller and the ATFCMAC. The parameters of the proposed ATFCMAC are tuned online using the adaptation laws that are derived from a Lyapunov stability theorem, so that the stability of the control system is guaranteed. The simulation and experimental results for a Duffing–Holmes chaotic system and a magnetic ball levitation system are used to verify the effectiveness of the proposed control scheme.

Rare foreign body in bladder

Rationale:The bladder is the most common site of foreign bodies in the urinary tract. Presenting complaints in patients with a foreign body are urinary retention, dysuria, frequent urination, decreased urine volume, nocturia, hematuria, painful erection, as well as pain in the urethra and pelvis.Patient concerns:A 50-year-old married male presented with complaints of severe lower abdominal pain and dysuria.Diagnoses:A plain radiograph of the pelvis showed a metallic dense foreign body that was composed of many small magnetic balls in the pelvic region.Interventions:The foreign body was removed under cystoscopy, and 67 magnetic balls were detected without any surgical or postsurgical complications.Outcomes:During operation, A cystoscopic examination confirmed no residue.Lessons:The bladder is the most common site of a foreign body in the urinary tract.Most intravesical foreign bodies can be removed transurethrally and with minimum access. The best mode of management depends on the nature of the foreign body, lodged site, expertise of the surgeon, and available instruments.

Note: A simple magnetic field design for dichroic atomic vapor laser lock.

The dichroic atomic vapor laser lock (DAVLL) is a very useful scheme for frequency stabilization. A bias field on the order of 100 G is required to get the error signal for frequency locking. Here we report a simple design for the bias field with the permanent magnetic balls. It is really simple and easy to adjust the magnitude. Since the DAVLL lock is not sensitive to the bias field, such a design is very suitable.

A human locomotion inspired hybrid nanogenerator for wrist-wearable electronic device and sensor applications

The availability of realistic, wearable efficient energy harvesters for powering body-worn IoT devices and health monitoring sensors is essential, in order to reduce the dependence of these wearable electronic devices, on batteries. Herein, we demonstrate a novel curve-shaped wearable hybridized electromagnetic-triboelectric nanogenerator (WHEM-TENG), operating as a fully-enclosed light-weight low-frequency energy harvester, driven by human motion. The WHEM-TENG incorporates the swinging behavior of a human arm during locomotion, and the freestanding rolling mode of a magnetic ball. Simulations of the magnetic flux density and the triboelectric surface potential assisted in improving the design and performance of the nanogenerator. The harvester device was manufactured using a 3D-printing method, which makes the fabrication process faster, easier, and more cost-effective than traditional methods. The 3D-printing material was used as triboelectric material for the nanogenerator. Experiments illustrate that at the low input frequencies characteristic of walking and running, the electromagnetic generator (EMG) and triboelectric nanogenerator (TENG) deliver peak power densities of 5.14 mW/cm3 and 0.22 µW/cm3, across load resistances of 49.2 Ω and 13.9 MΩ, respectively. Moreover, we also demonstrate that the WHEM-TENG can drive a commercially available electric wrist-watch continuously for 410 s from the power generated by just 5 s of running activity. Also, we demonstrate a self-powered heart-rate sensor driven by the nanogenerator. The electrical output of this distinctively structured device is promising for optimization of similar hybrid wearable energy harvesters, and for practical applications, towards the development of self-powered wearable smart bands/watches and fitness/health monitoring sensors.