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Advanced Intelligent Mechatronics, 2009. AIM 2009. IEEE/ASME International Conference on

Date 14-17 July 2009

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Displaying Results 1 - 25 of 339
  • A step towards home-based robotic rehabilitation: An interface circuit for EEG/SEMG actuated orthosis

    Publication Year: 2009 , Page(s): 1998 - 2003
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (855 KB) |  | HTML iconHTML  

    The effectiveness of rehabilitation will be increased substantially (e.g. stroke patients) if the patients are able to use a robotic rehabilitation system at home, after having trained on it at the hospital. Due to high cost and complex architecture, most robotic orthoses are limited to use in the hospital. The "active" orthoses that make use of bio-signals for control purposes, are at present limited in their versatility, portability and usability. At the same time, studies show that rehabilitation speeds up when the level of patient engagement is higher. To make home-use a reality, it is of paramount importance that the system is low-cost, portable, reliable and simple to operate. An acquisition and control system which satisfies these goals will create a significant impact on patient adoption of robotic rehabilitation devices. The sub-system design that is described in this paper is part of a wider research work to develop an accelerated stroke rehabilitation platform utilizing an EEG/SEMG based upper extremity robotic orthosis. This sub-system forms the 'interface' between the patient and the computer / controlling device used for signal processing and orthosis control. Cost and weight is reduced significantly. The circuit can interface with industry standard data acquisition devices and switch seamlessly between surface electromyography (SEMG) and electroencephelography (EEG) operation. Test results are presented both with simulated signals as well as actual SEMG signals. View full abstract»

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  • Evaluation of wire bond integrity through force detected wire vibration analysis

    Publication Year: 2009 , Page(s): 1 - 5
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1080 KB) |  | HTML iconHTML  

    This paper studies the feasibility of using force measurement to detect wire vibration for the evaluation of wire bond integrity. In this system, a tapping probe sends a single pulse or multiple pulses of controlled motion to the substrate adjacent to a bond end. This mechanical shock induces vibration propagation to the wire along and through the neighbouring materials. Another probe of a micro force sensor is put in touch with the wire to pick up the wire vibration, which in turn, correlates to the bonding status of the joined materials. By interpreting the vibration signals in time, frequency, and phase domains, bond integrity, including fully bonded, partially bonded, and touching yet not-bonded, has been determined. The results show that the proposed approach is promising for finer and denser wire bond evaluation non-destructively, accurately, and at low cost. View full abstract»

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  • A two-way flexural rotation manipulator using opposing shape memory alloy wires

    Publication Year: 2009 , Page(s): 6 - 11
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (760 KB) |  | HTML iconHTML  

    This paper presents the design, fabrication, and control of a two-way rotational manipulator using opposing shape memory alloy (SMA) wire actuated flexures. Monolithic flexure mechanisms have no friction/backlash and are capable of miniaturization. SMA exhibits large stroke, high energy density, and requires low driving voltage. Combining SMA as driver and flexure as force/motion transmitter makes them well-suited for tasks that required high precision and packed space. To explore flexure shapes beyond traditional notch hinges and leaf springs, we present a general design method to find the optimal flexure shapes for maximal rotation without yield. The advantages gained from shape variations are shown through a simulation example. By parallel connecting two flexure mechanisms with two opposing one-way SMA wires, the manipulator achieves two-way motion without sacrificing stroke. By actively contracting and extending, two-way manipulators are much faster than owe-way manipulators that rely passively on bias spring to extend. A feedback PID control algorithm with fuzzy-tuning gains is implemented to precisely control the response of the manipulator. We illustrate the two-way performance by several tracking response experiments. With the merits shown, we expect this type of manipulator can be utilized in meso to micro scale applications. View full abstract»

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  • A shape memory alloy actuated microgripper with wide handling ranges

    Publication Year: 2009 , Page(s): 12 - 17
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (859 KB) |  | HTML iconHTML  

    A compliant two-fingered microgripper was designed, fabricated, and demonstrated. To accommodate objects of various sizes and weights, the gripper is distributively actuated by shape memory alloy (SMA) wires so that high gripping range to gripper length ratio and mechanical advantage are achieved. A SMA actuated gripper model is presented to predict SMA strain and gripper deflection by using measurements from force sensors. Based on this model, design of finger shape and specification of SMA wire dimension are facilitated. Two grippers with different stiffness are prototyped and their motion characteristics demonstrated. Due to the large stress provided by SMA wires, high gripping force can be obtained. The SMA contraction force to deflect gripper and produce gripping force may be adjusted by changing the input power to SMA wire. We further investigate the feasibility of self-sensing contraction force by using SMA resistance signal. With the capabilities of the gripper shown, we expect that it can be applied for miniature robotic manipulations. View full abstract»

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  • Vision-based compliant-joint polymer force sensor integrated with microgripper for measuring gripping force

    Publication Year: 2009 , Page(s): 18 - 23
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (403 KB) |  | HTML iconHTML  

    A vision-based sensing system is developed for the measurement of gripping force in a polymer microgripper system. The system is implemented by a force sensing arm integrated with a microgripper, a CCD with microscopic system, and an image processing algorithm. The integrated force sensor and microgripper mechanism is fabricated by utilizing polyurethane film. The microgripper is actuated by shape memory alloy. The gripping force on a copper rod of diameter 20 mum is analyzed, measured, and calibrated. The main specifications of the gripper system are: maximum force resolution (@0.86 mum/pixel) of 1 muN, sensitivity of 988.24 muN-mum/deg, maximum gripping force of 15 muN, maximum gripping size of 40 mum, and mechanism and actuator size of 937 times 477 times 600 mum3. View full abstract»

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  • Synchronization strategy research of pneumatic servo system based on separate control of meter-in and meter-out

    Publication Year: 2009 , Page(s): 24 - 29
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (431 KB) |  | HTML iconHTML  

    In the pneumatic synchronization system based on separate control of meter-in and meter-out, both motion trajectory and pressure trajectory could be tracked in a single pneumatic cylinder and then the cylinder could be controlled completely without internal dynamics. In this paper, an adaptive robust pressure controller is used to keep the pressure level in chamber of cylinder on an even keel when the pneumatic cylinder is moving, which will result in small variation of cylinder's friction force and facilitate the precise modeling of friction force, and an adaptive robust motion controller is designed to improve the motion tracking accuracy of pneumatic cylinder, and on-line parameter estimation of the flow coefficient is utilized to have improved model compensation, and moreover a synchronization controller is added to further reduce the synchronization error. Experimental results demonstrate that this synchronization strategy could not only make two cylinders synchronized moving accurately, but also obtain very smooth control inputs which indicate the effectiveness of model compensation. View full abstract»

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  • Effects of bio-joint models on compliant exoskeleton design

    Publication Year: 2009 , Page(s): 30 - 35
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (719 KB) |  | HTML iconHTML  

    This paper presents a method taking advantage of medically available MRI (Magnetic Resonance Imaging) data to derive the kinematics of a knee joint. The bio-joint model is applied to the design of a compliant sensing mechanism with two examples. The first investigates the effect of materials and characteristic geometry of the compliant mechanism on the knee joint, while the second (utilizing the bio joint model as boundary conditions to measure the knee joint rotation and internal forces involved) provides a better understanding on the interaction between the human knee and compliant sensing mechanism. The results potentially help establish a new topic of accommodating human bio-joint variations and nature degrees-of-freedom movements in the design of an exoskeleton. View full abstract»

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  • A master-slave control system with energy recycling and force sensing for upper limb rehabilitation robots

    Publication Year: 2009 , Page(s): 36 - 41
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (336 KB) |  | HTML iconHTML  

    An innovative bilateral master-slave control method for an upper limb rehabilitation robot system which can afford training for hemiplegic patients is introduced. The system consists of two identical motors with the master motor working in the generating state and the slave motor working in the electro motion state. Based on hemi-disabled characteristic of hemiplegic patients, the healthy limb is used to operate the master motor to generate electric energy, which in turn powers the slave motor to rotate and support impaired limb in motion imitation, thus realizing rehabilitation training. An experimental prototype with energy supplement control was developed. The appropriate amount of energy is provided for the master-slave closed-loop circuit to compensate the inside energy loss, and further to achieve good motion tracking performance. Test experiments were conducted and the results confirm that the proposed system is capable of achieving motion tracking, energy recycling, and force sensing without force sensors. Thus, this master-slave control system has a great potential for application in rehabilitation robot systems. View full abstract»

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  • Numerical and experimental studies on temperature field of rotary MRF dampers

    Publication Year: 2009 , Page(s): 42 - 46
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (479 KB) |  | HTML iconHTML  

    In this paper, the heat generation principle of rotary MRF (MagnetoRheological Fluids) dampers was investigated, a mathematical model of heat source distribution was proposed, the temperature field caused by the heat sources was numerically simulated by means of ANSYS software, and the law of temperature distribution and rise was revealed. On the basis, a forced water-cooling system for the MRF dampers was designed to solve the temperature rise problem. Experiments were also conducted. Both numerical and experimental studies showed that, during the running of the dampers without any cooling measures being taken, the temperature of the dampers would continuously rise to a very high level before heat exchange balance was reached; while a forced water-cooling system was applied, the time for arriving at the heat exchange balance would be much shorter, and the temperature rise could be controlled within 20degC that is permissible for the practical application of the dampers. View full abstract»

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  • Dual differential rheological actuator for robotic interaction tasks

    Publication Year: 2009 , Page(s): 47 - 52
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (303 KB) |  | HTML iconHTML  

    Robots fail to perform complex manipulation or locomotion tasks when using simple force or motion controllers applied to classic actuators. Stability and safety issues arise for reasons such as high output inertia and the non-collocation of sensing and actuating transducers. This paper presents a new actuation concept, integrating a DC motor and two differentially coupled magnetorheological brakes, promising safe and versatile interaction capabilities. This paper focuses on the underlying mechanism and a case study with a proof-of-concept prototype. View full abstract»

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  • A novel approach to fabric control for automated sewing

    Publication Year: 2009 , Page(s): 53 - 58
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (861 KB) |  | HTML iconHTML  

    This paper describes a novel fabric manipulation method for fabric control during the sewing process. It addresses issues with past attempts concerning fabric position and tension control. The method described involves replacing the current sewing feed mechanism with a servo controlled manipulator to both feed and control the fabric. The manipulator is coupled with a machine vision system that tracks the threads of the fabric to provide real-time position control that is robust with respect to fabric deformations. A prototype of the manipulator is used to demonstrate the feasibility of the concept, reaching accelerations up to 27 g's and following a closed loop trajectory with open loop control while operating in coordination with an industrial sewing machine. The system described also offers a general solution to high accuracy and high acceleration position control systems. View full abstract»

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  • Throwing of cylinder-shaped objects

    Publication Year: 2009 , Page(s): 59 - 64
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (2006 KB) |  | HTML iconHTML  

    In a research project we are working at a new high performance technology for the transportation of objects within production systems. Objects shall be thrown or shot from one working station to another. Up to now only ball-shaped objects were thrown, where no orientation had to be considered. At real objects in real production systems however it is important to retain the orientation of the objects during the transportation. In this paper it is presented how cylinder-shaped objects can be thrown accurate and with a stable orientation over distances of about 3 meters. View full abstract»

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  • Towards the position control of conducting polymer trilayer bending actuators with integrated feedback sensor

    Publication Year: 2009 , Page(s): 65 - 70
    Cited by:  Papers (5)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (397 KB) |  | HTML iconHTML  

    Conducting polymers have a wide range of reversibly controllable properties, leading to a number of potentially useful devices for robotic applications, including actuators, sensors and batteries. Conducting polymers have the advantages of low weight, low cost, flexibility, small activation potentials (<2V), biocompatibility and the ability to be manufactured using relatively straightforward techniques. Trilayer bending actuators which utilise the controllable change in volume of conducting polymers are potentially useful devices, but their speed and positioning ability must be improved. Significant research effort has been directed towards improving conducting polymer actuator performance through its chemistry, but the use of compensating control systems has had relatively little focus. This paper experimentally investigates three potential control systems for a trilayer bending actuator - feedforward gain control, feedforward inversion-based control and inversion-based PI control. It was found that the inversion-based PI control system provided the best performance, but the implementation utilised a large laser displacement sensor. To limit the requirement for such a large feedback sensor, a trilayer bending actuator with an integrated displacement sensor is proposed, exploiting the additional sensing capability of conducting polymers. View full abstract»

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  • Precision smart force platform

    Publication Year: 2009 , Page(s): 71 - 75
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1138 KB) |  | HTML iconHTML  

    The precision smart force platform is divided into three main sections; the platform, data acquisition circuit, and software. The purpose of this research work is to design and to develop a precision force platform, which can be widely used to measure vertical ground reaction force of the human body in various daily activities i.e. walking, jogging and jumping. To produce precise and accurate measurement of the ground reaction force, FlexiForce A201-100 is utilized as the main sensing device. This sensor uses the electrical property of resistance to measure the applied force. Inside the force platform, these force sensors are arranged in an array form to measure the applied force. Measurements collected from the force platform are sent to a computer for further processing and data analysis. To enhance the mobility of the force platform, the force platform is designed in such a way that it is foldable, light and durable. The board is designed to have dimension of 500 mm times 450 mm with thickness of 12 mm. In addition, the sensors are encased in exquisite acrylic layers giving it a futuristic and pleasing appearance. View full abstract»

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  • Performance evaluation of a flexure-based five-bar mechanism for micro/nano manipulation

    Publication Year: 2009 , Page(s): 76 - 81
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (472 KB) |  | HTML iconHTML  

    This paper presents the design, fabrication and experimental methodologies for a flexure based five bar mechanism, which is indispensable for the applications of micro-nano scale operations. To overcome the limited displacement of such a flexure based mechanism driven by piezoelectric actuators, lever mechanisms are used to enlarge the working range in Cartesian space. The mechanical design of the micro-manipulator is firstly described. Based on the configuration of the proposed flexure based mechanism, the kinematic model is developed. The linearised relationship between the actuation space and the Cartesian space is derived according to the kinematic analysis. Finite element analysis (FEA) is carried out to guarantee the long-term repeatability accuracy and examine the performance of the developed compliant mechanism. Experiments are implemented to cross validate the characteristics of the developed flexure-based mechanism. View full abstract»

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  • Modeling and analysis of a new flexure-based micropositioner for precision manipulation

    Publication Year: 2009 , Page(s): 82 - 87
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (278 KB) |  | HTML iconHTML  

    This paper focuses on the development of a new high precision micropositioning device that is capable of traveling in translational and rotational motions. The device was modeled via the application of flexural cantilever structure to harness the precision and accuracy in implementing the positioning routine. This attribute is paramount to enable further manipulation procedures such as grasping, injecting, mounting, assembly and machining to be performed. A new hinge configuration was specifically designed to provide the micropositioner platform with 3-degree of freedom motion capability (x-y-thetas). Furthermore, a new approach in delivering the actuated motion has been devised via the utilization of slander beam profile acting in pressing mode which is critical in improving the performance of the device particularly in extending its capability to operate within high frequency range. The modeling procedure was realized via the combination of Pseudo Rigid Body Model (PRBM) and Finite Element Analysis (FEA). Analysis was performed within simulation environment to observe and verify the performance of the proposed model under various modes of motions. The analyses authenticate the capacity of the micropositioner to demonstrate high accuracy and fidelity motion. View full abstract»

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  • Real-time vision-based microassembly of 3D MEMS

    Publication Year: 2009 , Page(s): 88 - 93
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (1954 KB) |  | HTML iconHTML  

    Robotic microassembly is a promising way to fabricate micrometric components based three dimensions (3D) compound products where the materials or the technologies are incompatible: structures, devices, Micro Electro Mechanical Systems (MEMS), Micro Opto Electro Mechanical Systems (MOEMS), etc. To date, solutions proposed in the literature are based on 2D visual control because of the lack of accurate and robust 3D measures from the work scene. In this paper the relevance of the real-time 3D visual tracking and control is demonstrated. The 3D poses of the MEMS is supplied by a model-based tracking algorithm in real-time. It is accurate and robust enough to enable a precise regulation toward zero of a 3D error using a visual servoing approach. The assembly of 400 mum times 400 mum times 100 mum parts by their 100 mum times 100 mum times 100 mum notches with a mechanical play of 3 mum is achieved with a rate of 41 seconds per assembly. The control accuracy reaches 0.3 mum in position and 0.2deg in orientation. View full abstract»

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  • Towards automated robotic nanomanipulation systems

    Publication Year: 2009 , Page(s): 94 - 99
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (821 KB) |  | HTML iconHTML  

    This paper describes the key components that need to be developed, implemented and integrated in order to make full automation on the nano-scale possible. Multiple nanohandling robots are integrated into a flexible robot cell that can quickly adapt to different manipulation scenarios. An approach for the physical actuation of the employed smart actuators is given. A real-time capable control architecture makes efficient and reliable automation possible. With specialized methods of collision avoidance and path planning, the actual automation sequences can then abstract from the complex task of motion planning for individual robots. Furthermore, the major challenges when performing calibration and adjustment on the nanoscale are highlighted. View full abstract»

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  • Robust gait control for steady swimming of a carangiform fish robot

    Publication Year: 2009 , Page(s): 100 - 105
    Cited by:  Papers (2)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (838 KB) |  | HTML iconHTML  

    The sinusoidal gait, which is commonly seen in the steady swimming of fish, is applied and controlled on a carangiform fish robot in this paper. Because of the unmodeled hydrodynamics and the uncertainties among parameters of mathematical model of fish tail, it is critical for the motorized tail system to track the sinusoidal gait functions in water environment. The periodical oscillation of the caudal fin results in continuously varying drag forces from water, which brings strong disturbance to the control system. Two methods are used to solve this problem. Firstly, the disturbance is treated as a linear velocity damping with a constant damping coefficient. A PD controller is applied to regulate the tracking system. However, this method shows limited capabilities when the frequency and amplitude of gait functions change. The second method is to incorporate the mathematical model of the disturbance into the controller design. The robust tracking is then provided in an extended error space. Compared with the result of PD control, the system response with the robust design shows superior performance in tracking sine input and reducing disturbance caused by the interaction force with water. Derivation of the equations for the controller design is presented. Experiment setup and results are also described. View full abstract»

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  • A variable stiffness MR damper for vibration suppression

    Publication Year: 2009 , Page(s): 106 - 111
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (223 KB) |  | HTML iconHTML  

    This paper presents the development of a magnetorheological (MR) fluid-based variable stiffness damper and analysis its applications in vibration suppression. The MR fluid isolator used a MR valve control unit and bladders to achieve the variable stiffness and damping in stepless and relative large scope. A mathematical model of the isolator was derived, a prototype of the MR fluid isolator was fabricated and its dynamic behavior was measured in vibration under various applied magnetic fields. The effective stiffness and damping coefficients of the isolator under various magnetic fields were identified and the dynamic performances of isolator were evaluated with simulation. The results demonstrated that the developed MR bladder system can efficiently suppress the structural vibrations. View full abstract»

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  • Input-output transition models for discrete-time switched nonlinear systems

    Publication Year: 2009 , Page(s): 112 - 117
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (216 KB) |  | HTML iconHTML  

    Switched systems are usually given in the state space form, as state space models provide a more complete description of the system dynamics. In practice, however, we often make use of input-output models for identification and control purposes. Vast literature acknowledges that if we have one input-output model corresponding to each subsystem of the switched system, then at the switching instants, none of these input-output models can properly describe the system behavior. In our earlier work, we derived for switched linear systems the explicit form of the input-output models at the switching instants, which are termed as the transition model. In this paper, we show that similar input-output transition models also exist for switched nonlinear systems. Simulation shows that utilizing these transition models improves the identification of switched nonlinear systems significantly. View full abstract»

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  • Determining the mass and angular position of the unbalanced load in horizontal washing machines

    Publication Year: 2009 , Page(s): 118 - 123
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (260 KB) |  | HTML iconHTML  

    Horizontal washing machines use significantly less water and energy as opposed to conventional machines. Unbalanced load in washing machines limit the performance, and therefore accurate estimation of unbalanced loads, including their magnitudes and locations in washing drum, is required. In this paper, we propose an approach to evaluate the angular position and mass of the unbalanced load. A simulation model of the system was developed and various experiments were performed. The proposed algorithms and the developed experimental system can estimate the angular position of the unbalance load with maximum %3 error. The research on unbalanced load increase the performance of the washing machine and in addition to this, this research can be used to eliminate unbalanced load in future studies. View full abstract»

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  • Towards the deployment of industrial robots as measurement instruments - An extended forward kinematic model incorporating geometric and nongeometric effects

    Publication Year: 2009 , Page(s): 124 - 129
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (244 KB) |  | HTML iconHTML  

    In the area of mounting and spot-welding of body-in-white, absolutely accurate robots are installed as measuring instruments, replacing expensive coordinate and other external measuring machines. Measurement technologies based on industrial robots play an increasingly important role. Such applications require highly accurate robots. Prior to deployment of highly accurate robot, however, it needs to be ensured that the implemented robot model fits the real model. Robot calibration can offer a significant opportunity to improve the positioning accuracy and to cut production costs. Existing calibration approaches fail to capture geometric and elastic effects occurring in the robot forward kinematics. Therefore, in this work an extended forward kinematic model incorporating both geometric and elastic effects has been developed in which the positioning accuracy of a manipulator, with or without an accurate internal robot model in the robot controller, is improved. View full abstract»

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  • Axial position and speed vector control of the inset permanent magnet axial gap type self bearing motor

    Publication Year: 2009 , Page(s): 130 - 135
    Cited by:  Papers (1)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (543 KB) |  | HTML iconHTML  

    Magnetic bearing motors have many advantages such as no friction loss, no abrasion, lubrication-free quality, very high speed and so forth. However, they are not widely used due to their high cost, complex control and large size. In order to solve these problems, a self-bearing motor is a reasonable trend in current researches. This paper will introduce an inset permanent magnet type axial gap self bearing motor, which is an electrical combination of an axial thrust bearing and an axial flux motor, as well as the method of controlling axial position and rotating speed of the motor. First, the axial force and the motoring torque are analyzed theoretically and then the control method is derived. In order to confirm the proposed technique, a motor has been made and tested. The experimental results confirm that the motor works stably with the proposed vector control, and the rotating torque and the axial force can be controlled independently. View full abstract»

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  • A hierarchical fuzzy inference method for skill evaluation of machine operators

    Publication Year: 2009 , Page(s): 136 - 141
    Cited by:  Papers (3)
    Save to Project icon | Request Permissions | Click to expandQuick Abstract | PDF file iconPDF (267 KB) |  | HTML iconHTML  

    In machine work, the productivity, energy efficiency, and the quality of the work depend strongly on the skills of the human operator. This paper proposes a hierarchical method for skill evaluation of human operators in machine work during their normal work. The method refines skill metrics obtained from work cycle recognition-based evaluation system proposed earlier by the authors. The proposed skill components are: machine controlling skills, control parameter tuning skills, knowledge of the work technique and strategy, and planning and decision making skills. The skill components in each task are evaluated by a dedicated fuzzy inference system, whose rule base is generated automatically. The method is utilized to evaluate skills of nine operators of a cut-to-length forest harvester. View full abstract»

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