International Journal of Mechatronics and Automation (15 papers in press)
Verification of Unique Cloth Handling Performance Based on 3D Recognition Accuracy of Cloth by Dual-eyes Cameras with Photo-model-based Matching
by Khaing WIN PHYU, Ryuki FUNAKUBO, Fumiya IKEGAWA, Mamoru MINAMI
Abstract: Nowadays, innovative robotic technology has been implemented in the garment companies.rnHowever, robots have been confronted with difficulties in recognizing and handling deformable object such as cloth, string etc., especially if the object is unique. rnSpecifically, the cloth placed in front of the robot is rightly the intended one to be handled and to pick and place (handle) at a designated position automatically are two main problems during 3D cloth recognition and handling performance by a robot.rnIn this paper, model generation method from cloth photograph and model-based matching method (recognition method) utilizing Genetic Algorithm (GA) are presented. rnThe proposed system uses dual-eyes cameras to recognize the target cloth and estimate the pose of that cloth for handling.rnThe proposed system is used to verify the 3D handling under predetermining position and orientation range.rn100 times handling experiment has been executed, having shown the effectiveness of proposed photo-model-based cloth recognition system.
Keywords: Genetic Algorithm; Photo-model-based Matching; Dual-eyes Cameras; 3D Recognition; Unique Cloth Handling.
Homogeneous Light Transport (HLT) Matrix estimation based 3D shape measurement
by Naoya Chiba, Koichi Hashimoto
Abstract: We introduce Homogeneous Light Transport (HLT) Matrix for efficient 3D measurements. Which is an extension of the Light Transport (LT) matrix. The LT Matrix is a model of light transportation between a projector and a camera. It describes weights for all combinations of the projector pixels and the camera pixels. The HLT Matrix includes background lights information with LT Matrix. By using the HLT Matrix, we can estimate LT Matrix without backgrounds measurement. In the traditional methods, it is assumed that the light ray reflects only once in the scene. However, in the actual scenes, it may reflect multiple times due to specular reflections or subsurface scatterings; thus 3D measurement may become difficult in some cases. The LT Matrix can express multiple times reflection. In this paper, we demonstrate that 3D points can be measured by using ``1-pixel projection\'\' and considering the epipolar geometry, for measurement targets which are difficult to measure by traditional methods. This measurement is the same as the measurement using the LT Matrix approach. We use a compressive sensing method for estimation to reduce the number of projection and capture.
Keywords: 3D Measurement; Homogeneous Light Transport Matrix; Compressive Sensing; Projector-Camera System.
Integrated Optimization of the Flexible Resource Workload Balancing and Investment Project Scheduling Problem
by R.E.N. Yifei, L.U. Zhiqiang
Abstract: In this paper, we investigate the extension of the Resource Investment Project Scheduling Problem: the Flexible Resource Workload Balancing and Investment Project Scheduling Problem (FRWBIP). The integrated optimization of FRWBIP is established with the objective of minimizing the weighted resource availability cost and workload balancing penalty. A heuristic algorithm is designed to obtain the upper and lower bounds of resource requirements. The skills of the flexible resources are effectively allocated by the minimum cost-maximum flow flexible resource allocation model. A genetic algorithm with an improved serial schedule generation scheme and the resource usage adjustment module is proposed to solve FRWBIP. Every individual of the population is constructed from two lists: the activity priority list and the resource capacity list. Finally, a series of computational experiments are carried out by using the modified standard example library PSPLIB, and the effectiveness of the algorithm is verified by comparison with other literature algorithm.
Keywords: Flexible resources; Workload balancing; Resource Investment; Project Scheduling Problem; Genetic Algorithm.
Modeling, Design, and Real Time Implementation of Robust H-infinity Position Control of Piezoelectric Actuator Drive
by Mouhanned Brahim, Yves BERNARD, Imen BAHRI
Abstract: This paper deals with the modeling, design, and implementation of robust H-infinity position controller of Piezoelectric Actuator Drive (PAD). The PAD is an accurate rotary piezoelectric motor that employs the elongation of stack actuators and the micro-toothed ring and shaft to generate precise rotation motion. The motor position depends on precise adjustment between the motor ring and shaft and therefore demand a closed loop control to overcome the maladjustment problems. In this paper Simulink model of the PAD is firstly proposed. Robust H∞ position controller is then designed, implemented, and validated by simulation and experimental tests.
Keywords: Piezoelectric motor; PAD; H-infinity Robustness Position control.
Design and Control of an Assistive Exoskeleton with Passive Toe Joint
by Ali Taherifar, Afshin Shariat, Reza Khezrian, Ahmad Zibafar, Amir Reza Rashidi, Hossain Rostami, Golamreza Vossoughi, Ali Selk Ghafari
Abstract: Several exoskeletons with various configurations and degrees-of-freedoms (DOFs) have been introduced in the literature, but not many have addressed the optimal selection of the mechanisms DOFs. In the proposed system a semi-passive toe joint is introduced to achieve several advantages during walking with various speeds, including extended joints ranges of motion for kneeling and climbing of higher steps. The performance of the proposed novel passive toe joint is evaluated experimentally. In addition, the semi-passive abduction/adduction DOFs in the hip joint and eversion/inversion DOFs in ankle joint is proposed to facilitate turning while providing more comfort during normal walking. The effect of passive DoFs existence on the user comfortability is studied with the aid of three kinematic indices.rnIn the proposed mechanism, a set of compact, low-backlash rotary series elastic actuators are designed and incorporated to actuate the joints. The performance of the prototype exoskeleton is evaluated during the walking. A novel torque control is also introduced and evaluated experimentally. Results show good performance of the robot in zero-force control and impedance control during swing phase of motion.rn
Keywords: Lower Limb Exoskeleton; Passive Toe Joint; Kinematic Indices; Human-Robot Interaction; Zero-Force Control; Assistive Robot; Rehabilitation; Impedance Control; Series Elastic Actuator;.
Performance of Flux Switching Integrated Starter-Generator system with dual-mode control circuit
by Minchao Cui, Shengdun Zhao, Yoshihiro Deguchi, Chao Chen, Dengzhu Fan
Abstract: Flux Switching Integrated Starter-Generator (FSISG) system was employed to solve the global environmental problems and energy issues. The output performance is vital to the application of FSISG system in Hybrid Electric Vehicle (HEV). In order to investigate the performance of FSISG system, a design methodology of FSISG, a dual-mode control circuit and the relevant control methods were discussed and studied in this paper. Then the experimental investigations were carried out based on the drivers which were manufactured according to the designed dual-mode control circuit. The results demonstrate the excellent performance of FSISG system with dual-mode control circuit. In generating mode, the output voltages of FSISG show a high precision and a well stability in wide rotational speed range. In starting mode, FSISG system shows a well dynamic performance under the different load conditions and load variation condition.
Keywords: Integrated Starter-Generator; Hybrid Electric Vehicle; dual-mode control circuit; experiments; performance.
Bilateral Human-In-The-Loop Tele-Haptic Interface for Controlling a Robotic manipulator
by Jose James, Dhivin Davis, Gokulnath K, Bhavani Rao R
Abstract: Effective human-robot interaction is a factor deemed necessary for control of industrial robots and manipulators. Fine manual control and calibration tasks for an industrial manipulator can be daunting for novice users. In current manipulator systems, the human operator often times has to access the robot work space in order to manually set the robot parameters. In this paper, the authors proposed a bilateral haptic interface for controlling a robotic manipulator using a haptic device. This allows the human operator to intuitively jog and fell the manipulator from a remote station. The proposed system architecture consists of slave robot manipulators which controlled by moving the master haptic devices that can give haptic feedback to the user. Such a human-in-the-loop approach to control a remote robotic system offers a pragmatic solution when the robotic system is operating under dynamically changing environments and dexterous tasks. The proposed system has been initially tested on the simulation interfaces like V-REP and MATLAB that receives the position control signals from Chai3D in order to manipulate a virtual manipulator and finally implemented on real robot manipulator arm. The inclusion of haptic feedback offers the potential to augment the operators control task and overcome the limitations of visual perception within the robots operating environment. This paper also covers the force sensor experiments that help in classifying object properties that are needed to render haptic feedback as the slave robot touches both rigid and deformable surfaces.
Keywords: Tele-haptics; Human-Robot interaction; Haptic interface; Robotic Manipulator.
Hovering control of a quadcopter using linear and nonlinear techniques
by Harikrishnan Suresh, Abid Sulficar, Vijay Desai
Abstract: This paper presents a comparative study on linear and nonlinear control techniques for the near-hover attitude stabilization of a quadcopter. A dynamic model of the quadcopter is developed using Newton-Euler equations, which is inherently nonlinear. Firstly, the classical PID controller is implemented directly on the nonlinear system by decoupling the attitude dynamics and using separate controllers for each attitude variable. Linear controllers can also be implemented on this system by linearising it about an operating point, which is shown for the Linear Quadratic Regulator. Such a linear approximation may not always retain the actual system dynamics and are not very efficient in the real world scenario. Model based nonlinear controllers prove to be superior in such instances, and one such popular technique - Feedback Linearisation using dynamic inversion is discussed in this paper. The proposed control algorithms are tested on the quadcopter model using numerical simulations in MATLAB/Simulink and analysed in terms of fall time, percentage undershoot and computation time.
Keywords: Quadcopter; Newton-Euler formulation; Attitude control; Nonlinear control; PID control; Linear Quadratic Regulator; Model based control; Feedback linearization; Dynamic inversion; MATLAB/Simulink.
Application of Artificial Neural Networks for the Fault Detection and Diagnosis of Active Magnetic Bearings
by Anand Reddy, Praveen Kumar Agarwal, Satish Chand
Abstract: Active magnetic bearings (AMBs) are the class of advanced mechatronic systems. It is found that the stable operation of AMBs mainly depends on the normal operation of its sensors and actuators. Also these components have higher chances of getting malfunctioned under varying environmental conditions. Malfunctioning in any one of it may disturb the stability of AMB rotor. Therefore, to certify the reliability and security of AMB systems, on-line fault detection and diagnosis (FDD) of the sensors and actuators of AMB system is very essential. Various model based and redundant component based methodologies have been proposed for the FDD of sensors and actuators of AMBs. Model based fault diagnosis methods require complex mathematical modelling and have higher chances of subjected to modelling errors. Redundant sensors and actuators based methods incur additional cost and also require additional space for installation. Therefore, in the present work, simulation data driven Artificial Neural Network (ANN) based methodology is proposed for the FDD of AMBs. Fault in single position-sensor or actuator as well as multiple sensors and actuators are detected and diagnosed simultaneously. Various types of faults such as; bias, multiplicative and noise addition are considered for the diagnosis.
Keywords: Active magnetic bearing; sensors and actuators; fault detection and diagnosis; artificial neural network.
Fabrication and Characterization of RF MEMS Capacitive Switches Tuned for X and Ku Bands
by E.S. Shajahan, M.S. Bhat
Abstract: MEMS capacitive switches discussed in this paper employ electrostatic
actuation to perform switching action. Capacitive switches are designed by employing inductive tuning for excellent switching characteristics in X and Ku bands. Typical isolation characteristics of RF MEMS switches show a moderate value of -30 dB extending over a wider bandwidth. Employing inductive tuning is found to increase the switch beam inductance by a few tens of pico henries. This enhances the Q factor and has the effect of tuning the isolation performance of the switch over a narrow band of frequencies.Inductive tuning is achieved by creating recess in the ground plane of coplanar waveguide (CPW)in close proximity to the switching membrane. Membrane inductance enhancement can also be achieved by employing folded suspension beams. Since the current is concentrated on the edges of the conductor carrying RF signal, the part of the beam over the CPW
gaps will have dominating eect over the beam inductance. Beam inductance can be
extracted from the simulated isolation characteristics of the switch by curve fitting. This paper presents design, fabrication and characterization of inductive tuned MEMS capacitive switches with good isolation characteristics tuned for X and Ku bands. The devices are fabricated on high resistive (10 K Ohm
) silicon substrate by a ve mask surface-micromachining process. The electromechanical characterization of the fabricated devices are conducted using Cascade probe station and high frequency Power network analyzer. Characterization results show an actuation voltage of 18.5 volts. The insertion loss and isolation are better than 0.5 dB and -40 dB respectively in the 8-18 GHz band. The excellent RF characteristics make the switches suitable for high frequency applications.
Keywords: Inductive; MEMS; Electrostatic; Isolation; Surface-micromachining;Membrane; Fabrication; Proximity; RF characteristics; Insertion-Loss.
Fault diagnosis and prognosis in discrete event systems using statistical model and neural networks
by Mohammed Msaaf, Fouad Belmajdoub
Abstract: This paper deals with fault diagnosis and fault prognosis in discrete event systems described by sequences of events. We are interested in large industrial systems where the modelling with tools usually used for discrete event system (automata, Petri net) is a complex task. The description of DES is made with a statistical model composed of events recorded from the considered DES and regrouped in form of temporal windows. In the first phase, the theoretical framework is developed to perform diagnosis and prognosis using statistical model and temporal window concept. The second phase uses the result of the first phase to train radial basic function neural networks that preform on-line diagnosis and on-line prognosis. A case study and several examples serving to illuminate the developed approach are given.
Keywords: Discrete Event Systems; Fault Diagnosis; Fault Prognosis; Statistical Model; Neural Networks; Radial Basic Function Neural Network.
Optimal Controller Design for Fully Decoupled 3D Transnational Pantograph Manipulator for High-Speed Pick and Place
by Manar Lashin
Abstract: In this work, a new controller called inverse optimal PID with Feed-Forward control which is designed in H∞ framework has been introduced and compared with PD like fuzzy controller for a new 3D translational pantograph manipulator. The new manipulator performs pure decoupled translational motions, high speed, rigidity besides its large workspace to size ratio. The dynamic model of this manipulator shows a complexity that prevents using conventional model based control methods. Therefore, a straightforward method is used to obtain a simpler nominal plant. However, an explicit form of the nominal Coriolis and centrifugal matrix still cannot be obtained. The new controller is designed to deal with such complexity and requires no explicit form of the dynamic model matrices. This work investigates, through a comparative study, the performance of the proposed controller and PD like fuzzy controller for the novel 3D pantograph manipulator under two standard pick and place cycles with different speeds and payloads. PD like fuzzy controller is chosen because it suits complex and nonlinear systems. The dynamic simulation is carried out via co-simulation of MSC-ADAMS and MATLAB/Simulink software. The simulation results show the robustness of the proposed controller against speed/payload variations up to $4$[kg].
Keywords: Optimal control; Robust controller; Feed-Forward; Pantograph; PD like fuzzy.
Real-Time 3D Measurement System for Micro-manipulation
by Kenichi Ohara, Shota Takagi, Masaru Kojima, Mitsuhiro Horade, Kazuto Kamiyama, Yasushi Mae, Tatsuo Arai
Abstract: Construction of an activated three-dimensional (3D) tissue outside the human body is highly desirable, and it is expected that micro-manipulation should be used to construct 3D organizations. rnIn micro-manipulation, it is difficult to obtain depth information, as an object is usually observed using an optical microscope. Thus, empirical techniques that require extensive practice are employed. To overcome this problem,rn a system that can perform real-time 3D measurements is indispensable. rnIn this study, an improvement in the speed of 3D measurements in a microhabitat is obtained, which would facilitate micro-manipulation and the construction of 3D cellular organizations.
Keywords: GPGPU; All-in-Focus Image; 3D Measurement; 3D Reconstruction; Micro Manipulation.
Installation Angle Offset Compensation of Puncture Robot Based on Measurement of Needle by CT Equipment
by Akisato Nagao, Takayuki Matsuno, Tetsushi Kamegawa, Takao Hiraki
Abstract: A medical procedure called Interventional Radiology(IR) is paid much attention in recent years. rnIR can be performed percutaneously while a doctor observes patient's fluoroscopic image. Therefore this surgical method is low-invasiveness method. rnIn this surgery, computed tomography (CT) equipment is often used. rnBut a doctor is exposed to strong radiation from CT. rnThus, we have developed a remote-controlled surgery support robot called "Zerobot". rnBecause Zerobot is placed in front of CT equipment by human, an angle offset from installation target position occurs.rnIf a doctor punctures without noticing that Zerobot has an installation angle offset, there is danger of hurting the part that should not be hurt around a target cancer.rnIn order to solve this problem, we propose the installation angle offset derivation method using a CT equipment and an angle offset compensation method is proposed.rnThen, effectiveness of proposed method is confirmed through experiments.
Keywords: Surgery Support Robot; Interventional Radiology; Puncture Robot.
Crawling and Foot Trajectory Modification Control for Legged Robot on Uneven Terrain
by Takashi Matsuzawa, Ayanori Koizumi, Kenji Hashimoto, Xiao Sun, Shinya Hamamoto, Tomotaka Teramachi, Nobuaki Sakai, Shunsuke Kimura, Atsuo Takanishi
Abstract: In this paper, we propose a crawling motion that a legged robot makes its feet and torso contact with the ground alternately. The crawling motion aims to reduce the risk of malfunction due to the impact forces caused by falling down for traveling across uneven terrain. In addition, we propose the foot trajectory modification method based on information obtained from force sensors and an attitude sensor. The control method contributes to avoiding a collision between its feet and the surface of uneven terrain. To verify the effectiveness of the proposed method, we suggested a model of uneven terrain using a dynamics simulator and conducted an experiment that a four-limbed robot gets over the modelled terrain. From the experimental results, it is confirmed that the robot can traverse uneven terrain by using the crawling motion and that the foot trajectory modification control method can improve the locomotion capability of the robot.
Keywords: Crawling; Foot Trajectory modification control; Legged Robot; Uneven Terrain; Disaster Response.