Miniature DC Motor Research Articles

Failure Probability Modeling of Miniature DC Motors and Its Application in Fault Diagnosis

This paper proposes a fault diagnosis method for miniature DC motors (MDCMs) in the presence of the uncertainties caused by material and random factors of the production process. In this method, the probability models of fault multiple features are established based on the advantage criterion of the maximum overall average membership to determine the distribution of fault multiple features. The fault diagnosis algorithm is synthesized to obtain the threshold ranges of fault multiple features according to different confidence levels. Experimental test results are presented and analyzed to validate the efficiency and performance of the proposed fault diagnosis method.

Smart Soft Actuators and Grippers Enabled by Self‐Powered Tribo‐Skins

AbstractSoft end effectors or grippers capable of grasping objects dexterously and efficiently have attracted increasing attention in a broad range of applications. This article describes a smart soft finger‐like actuator with fast response, accurate control, self‐powered pressure, and bending sensing capability by combing the cable‐driven actuation with soft triboelectric nanogenerators (TENGs). The soft actuator, driven by a miniature DC motor, is designed to have multiple segments of elastomer body split with triangular cuts to facilitate the bending actuation and conformal contact with target objects. Two types of TENGs are integrated with the soft actuator: a single‐electrode‐mode TENG to measure the contact pressure and an inner contact–separation‐mode TENG to detect the bending. With micropyramid structures, the tribo‐skin patches possess high sensitivity and good compatibility with the actuator and can actively detect proximity, contact, and pressure via self‐generated electricity. Based on the modular design approach, a gripper with three fingers is fabricated and tested for its grasping, sensing, and self‐powering performance. This gripper is capable of picking up different kinds of objects, providing sensory feedback, and generating electricity, which shows great potential for use in robot–human and robot–environment interaction applications.

Novel morphing wing actuator control-based Particle Swarm Optimisation

AbstractThe paper presents the design and experimental testing of the control system used in a new morphing wing application with a full-scaled portion of a real wing. The morphing actuation system uses four similar miniature brushless DC (BLDC) motors placed inside the wing, which execute a direct actuation of the flexible upper surface of the wing made from composite materials. The control system of each actuator uses three control loops (current, speed and position) characterised by five control gains. To tune the control gains, the Particle Swarm Optimisation (PSO) method is used. The application of the PSO method supposed the development of a MATLAB/Simulink® software model for the controlled actuator, which worked together with a software sub-routine implementing the PSO algorithm to find the best values for the five control gains that minimise the cost function. Once the best values of the control gains are established, the software model of the controlled actuator is numerically simulated in order to evaluate the quality of the obtained control system. Finally, the designed control system is experimentally validated in bench tests and wind-tunnel tests for all four miniature actuators integrated in the morphing wing experimental model. The wind-tunnel testing treats the system as a whole and includes, besides the evaluation of the controlled actuation system, the testing of the integrated morphing wing experimental model and the evaluation of the aerodynamic benefits brought by the morphing technology on this project. From this last perspective, the airflow on the morphing upper surface of the experimental model is monitored by using various techniques based on pressure data collection with Kulite pressure sensors or on infrared thermography camera visualisations.

Design and demonstration of a bio-inspired flapping-wing-assisted jumping robot

Jumping insects such as fleas, froghoppers, grasshoppers, and locusts take off from the ground using a catapult mechanism to push their legs against the surface of the ground while using their pairs of flapping wings to propel them into the air. Such combination of jumping and flapping is expected as an efficient way to overcome unspecified terrain or avoid large obstacles. In this work, we present the conceptual design and verification of a bio-inspired flapping-wing-assisted jumping robot, named Jump-flapper, which mimics jumping insects’ locomotion strategy. The robot, which is powered by only one miniature DC motor to implement the functions of jumping and flapping, is an integration of an inverted slider-crank mechanism for the structure of the legs, a dog-clutch mechanism for the winching system, and a rack-pinion mechanism for the flapping-wing system. A prototype of the robot is fabricated and experimentally tested to evaluate the integration and performance of the Jump-flapper. This 23 g robot with assisted flapping wings operating at approximately 19 Hz is capable of jumping to a height of approximately 0.9 m, showing about 30% improvement in the jumping height compared to that of the robot without assistance of the flapping wings. The benefits of the flapping-wing-assisted jumping system are also discussed throughout the study.

Torque measurement method based on the Lorentz force law for miniature DC motor

This paper describes a torque measurement method for a miniature DC motor. The measurement principle is the Lorentz force law, that is, the equivalence in power between the electromagnetic torque and the motional electromotive force. The test bench that embodies the measurement needs no torque meter. Only a set of the same motors under test are sufficient, except for a digital oscilloscope, a DC power supply, and several resistors. The intrinsic measurement error related to the measurement principle is formulated by an equivalent circuit analysis of the DC brush motor. In addition, the superficial measurement error due to unevenness in electrical or mechanical characteristics between the two motors is clarified from the analysis. These measurement errors are experimentally evaluated for miniature DC motors on the market and the measurement accuracy is discussed. © 2017 Institute of Electrical Engineers of Japan. Published by John Wiley & Sons, Inc.

Matlab Simulink Simulation of Respiratory Effort Energy Harvester Using Electromagnetic Generator

Electromagnetic generator as respiratory effort energy harvester is designed as a renewable energy source to generate a low power and exploiting human motion to extract energy. By selecting respiratory effort as energy harvester it can be carried out 24 hours as long as the electromagnetic generator is wearing on the human chest. It is because the electromagnetic generator functions when there is a motion of the chest wall. The electromagnetic generator basically constructed with two miniature dc motor generator, pulley, belt, gear and chest belt. The generator operates when there is change in chest wall circumstance during exhalation breathing process. The low power that produces can be apply on low power devices such as sensor or microcontroller. Simulation is done using Matlab Simulink to verify that respiratory effort able to produce the minimum required power to power up low power devices. Result from the simulation showing good outcome with 2.5mW of output power.

Sensing and Force-Feedback Exoskeleton (SAFE) Robotic Glove.

This paper presents the design, implementation and experimental validation of a novel robotic haptic exoskeleton device to measure the user's hand motion and assist hand motion while remaining portable and lightweight. The device consists of a five-finger mechanism actuated with miniature DC motors through antagonistically routed cables at each finger, which act as both active and passive force actuators. The SAFE Glove is a wireless and self-contained mechatronic system that mounts over the dorsum of a bare hand and provides haptic force feedback to each finger. The glove is adaptable to a wide variety of finger sizes without constraining the range of motion. This makes it possible to accurately and comfortably track the complex motion of the finger and thumb joints associated with common movements of hand functions, including grip and release patterns. The glove can be wirelessly linked to a computer for displaying and recording the hand status through 3D Graphical User Interface (GUI) in real-time. The experimental results demonstrate that the SAFE Glove is capable of reliably modeling hand kinematics, measuring finger motion and assisting hand grasping motion. Simulation and experimental results show the potential of the proposed system in rehabilitation therapy and virtual reality applications.

Output Feedback Control of a Dual‐Excenter Vibration Actuator via qLPV Model and TP Model Transformation

AbstractVibration actuators are widely used in handheld devices to provide vibrotactile feedback or silent notification to the users. In most cases, miniature DC motors with eccentric rotors or the so‐called coin‐type shaftless vibration motors are utilized. The common disadvantage of the single rotor designs is that the frequency and the intensity of the generated vibration cannot be adjusted separately. The construction composed of two independently driven coaxial eccentric rotors – which makes a strongly coupled nonlinear system – allows for the separate control of the frequency and amplitude by the adjustment of the angular speed and the total eccentricity. This paper presents a complete control design approach based on quasi‐linear parameter varying (qLPV) modelling and linear matrix inequality (LMI)‐based synthesis utilizing the tensor product (TP) model transformation to determine the convex polytopic representation of the parameter dependent nonlinear system. The design approach is demonstrated via a concrete numerical example using the parameters of a real dual‐excenter prototype device. The control performance is validated through numerical simulations. This case study goes through a complete nonlinear control problem from the modelling phase to the implementation‐ready controller, while drawing generalizable conclusions for qLPV modelling.

An all-fiber-optic endoscopy platform for simultaneous OCT and fluorescence imaging.

We present an all-fiber-optically based endoscope platform for simultaneous optical coherence tomography (OCT) and fluorescence imaging. This design entails the use of double-clad fiber (DCF) in the endoscope for delivery of OCT source and fluorescence excitation light while collecting the backscattered OCT signal through the single-mode core and fluorescence emission through the large inner cladding of the DCF. Circumferential beam scanning was performed by rotating a 45° reflector using a miniature DC motor at the distal end of the endoscope. Additionally, a custom DCF coupler and a wavelength division multiplexer (WDM) were utilized to seamlessly integrate both imaging modalities to achieve an entirely fiber-optically based dual-modality imaging system. We demonstrated simultaneous intraluminal 3D OCT and 2D (surface) fluorescence imaging in ex vivo rabbit esophagus using the dual-modal endomicroscopy system. Structural morphologies (provided by OCT) and fluorophore distribution (provided by the fluorescence module) could be clearly visualized, suggesting the potential of the dual-modality system for future in vivo and clinical applications.

Bioinspired Aquatic Microrobot Capable of Walking on Water Surface Like a Water Strider

Walking on the water surface is a dream of humans, but it is exactly the way of life for some aquatic insects. In this study, a bionic aquatic microrobot capable of walking on the water surface like a water strider was reported. The novel water strider-like robot consisted of ten superhydrophobic supporting legs, two miniature dc motors, and two actuating legs. The microrobot could not only stand effortlessly but also walk and turn freely on the water surface, exhibiting an interesting motion characteristic. A numerical model describing the interface between the partially submerged leg and the air-water surface was established to fully understand the mechanism for the large supporting force of the leg. It was revealed that the radius and water contact angle of the legs significantly affect the supporting force. Because of its high speed, agility, low cost, and easy fabrication, this microrobot might have a potential application in water quality surveillance, water pollution monitoring, and so on.

Seeking Out the Spaces Between: Using Improvisation in Collaborative Composition with Interactive Technology

This article presents findings from experiments into piano and live electronics undertaken by the author since early 2007. The use of improvisation has infused every step of the process—both as a methodology to obtain meaningful results using interactive technology and as a way to generate and characterize a collaborative musical space with composers. The technology used has included pre-built MIDI interfaces such as the PianoBar, actuators such as miniature DC motors and sensor interfaces including iCube and the Wii controller. Collaborators have included researchers at the Centre for Digital Music (QMUL), Richard Barrett, Pierre Alexandre Tremblay and Atau Tanaka.

Design of a Wearable Fingertip Haptic Braille Device

Existing technologies and devices have facilitated the interaction of the blind or visually impaired (BVI) with their surroundings. However, reading remains an area where the potential of these technologies is not fully utilized. This work presents preliminary studies for the design of a finger-wearable E-Braille device that will allow the BVI to read electronic documents as they would read any document in Braille. The proposed device is wearable on a single finger on of the distal and middle phalanges (dorsal side). The main elements of the device are electrotactile display and force sensor. The electrotactile display is an electric board containing a matrix of electrodes that sends current to the fingertip for stimulating the touch feeling of a particular Braille character. By sending a sequence of Braille characters to this board, information can be sent to the user of the device through the generated electrotactile feeling. The force sensor is used in a feedback control loop to maintain steady contact pressure between the fingertip and the display board throughout the reading process. The entire finger-wearable E-Braille tactile display device is composed of a housing that can be customized to individual users, a miniature dc motor, mechanical components, and main elements. The initial testing of the proposed device is underway. Preliminary results indicate that the device can provide tactile sensation similar to that of reading a Braille document. The initial assessment of the device usability is underway.

Simulation of a miniature DC motor: Investigating the use of haptics and sound in detecting ripple torque

The numerical analysis of electromagnetic devices can generate large volumes of data describing the performance of the device. To date, this information has been provided to the user either as sets of numeric data or in graphical form. However, modern personal computers are actually capable of producing other forms of output. Among these are force feedback and sound systems. These are common in computer gaming but have not been explored in any depth in scientific result evaluation. This paper investigates the possible benefits in result understanding which may accrue from using these systems

Mesoscopic systems: bridging from micromachined devices to macroscopic systems

Mesoscopic systems are the bridge forming the micromachining domain into the macro-world. Additional challenges and opportunities are presented by mesoscopic systems. They require more 3-dimensionality than micromachined structures, provide the mechanical interface to the environment (i.e. act as the package) and must resolve the difference in tolerances between the macro-fabricated devices and the high precision microfabricated devices. An ideal fabrication technology for mesoscopic system is deep X-ray lithography (DXRL) and assembly. The high precision in the X, Y and Z dimensions of the DXRL-fabricated components provide unique opportunities for increased functionality and 3-dimensionality of mesoscopic systems. The fabrication, assembly, tolerance and metrology issues of DXRL fabrication of mesoscopic systems are presented. Application of these design issues to mesoscopic fluidic systems will be presented, with specific examples including a magnetically coupled gear pump, a gear pump driven directly by miniature brushless DC motor, and the fluid flat-pack, a general purpose packaging methodology for fluidic devices.

A device for low-temperature crystal reorientation in data collection with the oscillation method

A cold finger attached to the second refrigeration stage of a DE-201 Displex closed-cycle helium refrigerator has been equipped with a miniature DC motor. The device allows reorientation of the crystal at low temperature, without remounting or warming to ambient temperature. The axis around which the crystal is rotated is inclined by 45° to the cryostat axis, which gives a 90° change in orientation of the crystal upon 180° rotation.

Micro SCARA Robot for Miniature Parts Assembling

In this report, application of newly developed ultra-small servo actuators to a micro SCARA robot is presented. An ultra-small servo actuator consists of a miniature brushless DC motor, a reduction gear, and an optical encoder for monitoring the rotation of the motor. Two prototypes of different sizes were developed: one is 3mm in diameter and 10mm in length, and the other is 5mm in diameter and 18mm in length. Including the vertical positioning of the hand the robot has three degrees of freedom. First, the structure of the ultra-small servo actuator is shown and then the output characteristics of the 3mmdiameter and the 5mm diameter servo actuators are described, respectively. Next, the structure and control system of the micro SCARA robot, which has a 24.5mmlong arm, are described. Finally, flexible micro actuators, combined in parallel and acting a miniature handling system, are reported. They enable the gentle handling of small, fragile objects. The prototype of this micro SCARA robot enables the assembly of miniature objects in a small space. In the future, we expect this robot to find application as an inspection robot in narrow spaces, such as in small-diameter pipelines.