The bottleneck in introducing successful new products quickly to market is moving from factory floor manufacturing to the product design process and interfaces between designers, manufacturers and users. ‘Quality’, for products that contact people, has moved beyond functionality and usability to satisfying people’s subjective and emotional lifestyle needs. Affective (kansei) engineering design offers approaches that can be used to bring the emotional responses of consumers into the design process. In parallel, mass customisation promises the delivery of mass-produced bespoke products to individual users. Together, affective engineering and mass customisation are having a dramatic impact on the ways in which designers, engineers and manufacturers interact with each other. The challenge for leading edge manufacture is to create new product opportunities through integration of and new developments in technology, systems and design.

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Titanium alloys have been widely used in the aerospace, biomedical and automotive industries because of their good strength-to-weight ratio and superior corrosion resistance. However, it is very difficult to machine them due to their poor machinability. When machining titanium alloys with conventional tools, the tool wear rate progresses rapidly, and it is generally difficult to achieve a cutting speed of over 60m/min. Other types of tool materials, including ceramic, diamond, and cubic boron nitride (CBN), are highly reactive with titanium alloys at higher temperature. However, binder-less CBN (BCBN) tools, which do not have any binder, sintering agent or catalyst, have a remarkably longer tool life than conventional CBN inserts even at high cutting speeds. In order to get deeper understanding of high speed machining (HSM) of titanium alloys, the generation of mathematical models is essential. The models are also needed to predict the machining parameters for HSM. This paper aims to give an overview of recent developments in machining and HSM of titanium alloys, geometrical modeling of HSM, and cutting force models for HSM of titanium alloys.

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This paper describes the control of an XY nano-positioning table for a compact nano-machine tool. The aim of its controller design is to provide (1) high motion accuracy, (2) high robustness to disturbance forces and (3) high bandwidth. The controller has a PID element as a tandem compensator and a feedforward compensator. A bandpass filter is added so that the table system can show the mentioned specifications (1) and (2). The reference following characteristic and the robustness to disturbance forces are examined and evaluated theoretically and experimentally. The results prove that the table control system is suitable for a compact ultraprecision machine tool, attaining high positioning accuracy and frequency response up to 500Hz in a circular motion of a 100nm radius.

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This paper deals with an analysis of the chip area by ball end milling of an inclined surface using a contour path method. At first, the modeling of a cutter, an edge, a rake surface and a workpiece with an inclined surface are carried out using 3D-CAD. Secondly, the chip area is calculated by the interference of the rake surface and the chip volume. The influence of the cutting method and the direction of pick feed on the behavior of the chip area and the influence of the inclination angle of the machined surface on the maximum chip area are shown. And, the evaluation value E_d for cutting performance with the multiple by the chip area and the distance from the spindle axis to the center of gravity of the chip area is proposed. The evaluation value of the condition by stepping up pick feed and the inclination angle α=20° shows minimum, so a good cutting performance would be expected for these cutting conditions.

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The study deals with a new method to generate interference-free tool posture for 5-axis control machining using a ball end-mill. The 5-axis control machining can produce complicated shapes and parts consisting of overhanging and or sculptured surfaces such as impellers. However, high degree of freedom of 5-axis control machining center causes a fatal problem that other parts except cutting edges of the tool may interfere with other surfaces of the machining object. Therefore, it is necessary to obtain the adequate tool postures to avoid the interference during machining. The interference avoidance is generally performed by the method that cutting points are generated so as to be arranged on the surface to be machined, and then the interference-free tool posture is determined on each cutting point by the geometrical calculations. However, the method has a problem that it takes long time for calculation. To solve the problem, the study proposes a new interference avoidance method of reversing the order of the above procedure, i.e., that of determining a set of interference-free tool postures before generating cutting points. From the machining results, it is confirmed that the proposed method is available to fabricate complicated shapes since the impeller can be machined by using the method.

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In pocketing with contour parallel (CP) paths, the cutter encounters a varying engagement with the workpiece, which causes variation in chip load and cutting forces. This varying cutting force naturally leads to the variation of tool deflection, hence impairing machined surface accuracy. This paper presents a new tool path modification scheme, which regulates a constant cutting engagement with workpiece in 2.5D end milling. The semi-finishing path, the path prior to the finishing path, is modified by the proposed scheme such that the engagement angle along the finishing path is regulated at a desired level. By maintaining cutting engagement constant, the cutting force can be regulated approximately constant, thus minimizing the variation of tool deflection, and improving machining accuracy. The improvement of machining accuracy by applying the new tool path modification scheme is experimentally validated for the case where the proposed scheme is applied to pocketing. The machining results are analyzed and compared with the cases with conventional contour parallel path and the feed rate control scheme applied in pocketing.

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A virtual machining simulator (VMSim) for the flat end mill has already been developed, hence the VMSim for a ball end mill is developed in this research. This system consists of a geometric simulator and a physical simulator to evaluate the machining process. A direct calculation method of machining error copy points is newly proposed to represent the machining errors due to tool deflection in the geometric simulation, and the cutting force and the machining error prediction models for the ball end mill are also introduced in the physical simulation in this research. Furthermore, a basic modification of tool paths in order to reduce the machining errors is introduced. In case studies, the modification of tool paths is carried out and the feasibility of trial-less machining is discussed.

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A Wolter type I aspheric mirror which is a key optical element used in a soft X-ray microscope requires super smooth surface and highly accurate figure. This paper deals with fabrication of the Wolter type I microscope mirror by an epoxy replication method. The required figure accuracy of the mirror optimized with surface roughness of 2nm rms and photon energy of 539eV was estimated for a prototype soft X-ray microscope. A master mandrel was prepared by single-point diamond turning and polishing, and a precise aspheric gold mirror with axial symmetry was successfully obtained from the master mandrel through replication processes. The fabricated mirror showed surface roughness of 1.12nm Ra and figure error of 34nm rms, and several mirrors could be obtained from only one master mandrel without destroying its surface roughness and shape.

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Germanium is an excellent infrared optical material. On most occasions, single-crystalline germanium is used as optical lens substrate because its homogeneous structure is beneficial for fabricating uniform optical surfaces. In this work, we attempt to use poly crystals as lens substrates instead of single crystals, which may lead to a significant reduction in production cost. We conducted ultraprecision cutting experiments on poly-crystalline germanium to examine the microscopic machinability. The crystal orientations of specific crystal grains were characterized, and the machining characteristics of these crystal grains including surface textures, cutting forces, and grain boundary steps were investigated under various machining conditions. It was possible to produce uniformly ductile-cut surfaces cross all crystal grains by using an extremely small undeformed chip thickness (∼ 80nm) under negative tool rake angles (∼ -45°). This work indicates the possibility of fabricating high-quality infrared optical components from poly-crystalline germanium.

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Effect of atmosphere in ultra-micro cutting has been analyzed using MD (molecular dynamics) simulation carried out in such a way that potentials of surface atoms of diamond tool and silicon workpiece are modified when either of them is exposed to atmosphere. The results of the simulation show that principal cutting force decreases if the rake face of a tool and/or the rear face of chips are exposed to atmosphere during cutting. This result is consistent with the result obtained in microcutting experiments carried out by the authors and also indicates an important role of atmosphere in ultra-sonic vibration cutting.

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Dry drilling of composite/metallic stacks for aircraft components is extremely difficult to keep sufficient hole quality and efficiency of drilling process. Problems of the dry drilling of those kinds of stacks are chip ejection, chip formation and high temperature especially for titanium alloy. To clear these problems, low-frequency vibration (10-50Hz) drilling is proposed in this study. Controlled sinusoidal vibration was given in drill axis direction with constant feed motion. The relationship between vibration conditions, such as vibration amplitude, frequency and drill feed rate, and chip formation and drilling temperature were investigated. As a result, low-frequency vibration drilling can control chip formation to reduce chip jamming and can reduce drilling temperature. Temperature measured at the cap burr decreased by 300 degrees C or more when low-frequency vibration was applied compared with the conventional drilling. Also the wear rate of the drill is decreased when the vibration is applied.

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Series of orthogonal cutting tests of aluminum alloys have been carried out to investigate the chip formation process and adhesion of the work material to the rake face of the cutting tool under near dry cutting conditions. Almost no adhesion of the work material was observed over a wide range of cutting speed tested when the aluminum alloy was cut with the sintered diamond cutting tool. On the other hand, large amount of adhesion of the work material was observed at low cutting speeds, when cut with the carbide and DLC-coated tools. The amount of the adhered material is reduced with an increase in the cutting speed. The average coefficient of friction on the rake face increases almost in linear relation with the amount of adhesion. The chemical components of the adhered layer were also analyzed by EDS and AES techniques.

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To investigate the influence of the WC and Co contents, the cutting of five kinds of cemented carbides was carried out with the PCD tool. Moreover, one of them was the cemented carbides whose binder was Ni, and the influence of the binder was also found out. The tool wear width and the cutting forces were measured, and the worn flank was observed. Summary of results are shown as follows. (1) The tool wear didn’t always increased with increase of the Co content. (2) Not only the WC content but also the WC particle diameter influenced the tool life. (3) The adhesion could be found out in cutting every cemented carbides regardless of the content and composition. (4) The thrust forces were concerned with the flank wear.

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This paper deals with the grinding characteristics of newly developed polycrystalline cBN (cBN-U) abrasives in creep feed profile grinding of nickel-based superalloys. Experiments for producing a V-shaped groove on a flat surface in one pass by creep feed grinding have been carried out using the new polycrystalline cBN-U and representative conventional cBN (cBN-B) grits. When grinding with cBN-U abrasives, both radial wear and profile wear are less, and hence the grinding ratio is around 10 times higher than that with the conventional cBN-B abrasives. Grinding forces in grinding with cBN-U abrasives are reduced by 20-30% compared with those in Grinding with cBN-B abrasives. The cBN-U abrasive is suitable for the applications with a high dimensional accuracy in creep feed profile grinding for nickel-based superalloys, because it gives less profile wear, and hence better form retention, than conventional cBN abrasive.

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In this paper, we describe the formation mechanism of a finished surface in ultrahigh-speed grinding under a peripheral wheel speed higher than 200m/s. Grinding experiments using a grinding machine tool equipped with an active magnetic bearing spindle have been conducted over a range of grinding speeds from 60 to 300m/s. Moreover, grinding tests for producing some individual grooves using a grinding tool with multiple cBN grit have been carried out to clarify the effects of grinding speed on the side swelling formed along both sides of the grinding grooves. From the results of these experiments, we have confirmed that the roughness of the ground surface decreases with an increase in grinding speed, and this decrease is mainly due to the reduction of the swelling ratio with increasing grinding speed.

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The wheel surface topography in the grinding process with vitrified cBN wheels has been investigated on the basis of 3-dimensional analysis using a multi-probe SEM, and the relationships between these results and the grinding characteristic parameters have been discussed. Moreover, the change of the wheel surface profile in the grinding process has been evaluated using fractal analysis. There are two regions: an initial wear region and a steady-state wear region, in the grinding process. In the initial wear region, a rapid decrease of grinding force and a rapid increase of wheel wear occur with increasing stock removal. In the steady-state wear region, the micro self-sharpening phenomenon owing to the micro fracture as well as the attritious wear of cutting edge occurs. The change in fractal dimension of the wheel surface is closely related to the change of grinding force dominated by the wear behavior of grain cutting edges.

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To simulate cutting with abrasive grain in grinding, a random grain shape is modeled. The statistical distribution of the effective rake angles of abrasive grain is obtained by applying Usui’s four models of kinematically admissible velocity fields. The material is removed in the case of complete chip or incomplete chip formation, but is not removed when wall of partial chip or plastic upheaval is generated. Next, residual stock removal by bulging, which occurs due to effect of cutting speed, is presumed. A critical undeformed chip thickness, under which chip forms with great difficulty, is introduced. For further strict modeling, three components of cutting force are evaluated. As a result, a new model of surface generation process in grinding considering upheaval or residual stock removal, which is caused by the effect of grain shape and cutting speed, and of elastic deformation, is proposed.

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Dies made from AISI H10 die steel with narrow and deep gaps were nitrided by various manufacturers of equipment for ionic and gas nitriding. The manufacturers chose the optimum nitriding parameters themselves, based on their experience with extrusion dies. The resulting microstructures showed differences in terms of the presence or absence of a compound layer, the thickness of the layer and its ε/γ′ phase ratio (XRD), the nitriding depth and the microhardness values. The obtained nitriding depths, the maximum microhardness of the nitrided surfaces and the ε /γ^′ phase ratio were usually similar for dies from the same manufacturer, while the dies from different manufacturers tended to have different values. Samples with various nitrided microstructures were laboratory tested for wear resistance with a newly designed test rig that provided a simulation of the tribological conditions for the hot extrusion of aluminium. The results of the study indicate that dies with a greater nitriding depth in combination with a compound layer composed primarily of just one phase (in our case the ε phase) exhibited better wear resistance than those dies with a small nitriding depth and with an equal share of the two phases.

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Direct microjoining using Yttrium-Aluminium-Garnet (YAG) laser beams of copper wire and a plate or substrate board was carried out. The control of the behavior of the molten wire was extremely important to prevent joining defects such as evaporation or constriction of the wire. Both the contact angle between the wire and the plate and the distance from the tip of the wire to the laser irradiation point affected the improvement of the defect. Controlling the input heat by pulse waveform adjustment was also effective in controlling the melt behavior of the wire. Therefore, for plates 100 and 200µm thick, high peeling strength of 4N with little dispersion was obtained. However, for copper foil 70µm thick, the strength was poor and the dispersion was high. Because of the low heat capacity of the foil, the thermal condition of the wire extremely severe. Therefore, more details on input heat control are required.

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In this study, we simulated a wide cortex separation from a cementless hip prosthesis using the bone resorption remodeling method that is based on the generation of high compressive stress around the distal cortical bone. Thereafter, we estimated the effect on late migration quantities of the hip prosthesis produced by the interface state arising from bone ingrowth. This was accomplished using cortical bone remodeling over a long period of time. Two-dimensional natural hip and implanted hip FEM models were constructed with each of the following interface statements between the bone and prosthesis: (1) non-fixation, (2) proximal 1/3, (3) proximal 2/3 and (4) full-fixation. The fixation interfaces in the fully and partially porous coated regions were rigidly fixed by bony ingrowth. The non-fixation model was constructed as a critical situation, with the fibrous or bony tissue not integrated at all into the implant surface. The daily load history was generated using the three loading cases of a one-legged stance as well as abduction and adduction motions. With the natural hip and one-legged stance, the peak compressive principal stresses were found to be under the criteria value for causing bone resorption, while no implant movement occurred. The migration magnitude of the stem of the proximal 1/3 fixation model with adduction motion was much higher, reaching 6%, 11%and 21%greater than those of the non-fixation, proximal 2/3 fixation and all-fixation models, respectively. The full-fixation model showed the lowest compressive principal stress and implant movement. Thus, we concluded that the late loosening and subsequent movement of the stem in the long term could be estimated with the cortical bone remodeling method based on a high compressive stress at the bone-implant interface. The change caused at the bone-prosthesis interface by bony or fibrous tissue ingrowth constituted the major factor in determining the extent of cortical bone resorption occurring with clinical loosening and subsequent implant movement.

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The complicated relationships between hemodynamics and aneurysms have been investigated intensively. However, existing methodologies have inherent limitations in providing real blood flow fields. The authors have proposed Ultrasonic-Measurement-Integrated (UMI) simulation, in which the feedback signals lead to convergence of the calculated blood flow structure to the real one even with incorrect boundary/initial conditions. In UMI simulation, determination of the feedback law is substantially important, but detailed particulars remain to be accounted for. In this paper, first, the effects of density of feedback points and feedback domains are systematically investigated. Improvement of computational accuracy in the feedback domain is achieved even in low density of feedback points of 25%, and such improvement persists in the downstream region. Secondly, the most effective combination of feedback gains for momentum and pressure equations is investigated, confirming the validity of the simple condition to use the same value for the velocity and pressure gains.

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Vibration isolation methods that vary damping and stiffness have demonstrated excellent authority over system vibration, thus, potentially making them attractive for many applications. However, conventional devices for controlling variable stiffness are typically complicated and difficult to implement in most applications. To address this issue a new method is proposed that requires two magnetorheological (MR) fluid dampers placed in series. With this configuration, variable damping and stiffness vibration control is simultaneous achieved by varying a small electric current to the MR dampers. This paper presents a theoretical and experimental analysis of a two degree-of-freedom system that is controlled by the MR dampers. Five different control schemes involving combinations of variable damping and variable stiffness are explored. The time and frequency responses of the two degree-of-freedom system to a random input show that combined variable damping and stiffness control provides the best vibration isolation over a frequency range spanning the system’s two structural vibration modes. The experimental results agree well with the theoretical analysis.

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In this paper, a vehicle driving load estimation scheme in the form of a linear state observer is presented. The signals used in the observer are the transmission output speed and driven wheel speed, which are readily available in any vehicle equipped with an automatic transmission. Because the observer requires the turbine torque as input, the turbine torque itself has been estimated using a neural network. The proposed observer has been evaluated using a vehicle simulator in various driving situations considering transmission oil temperature variations, engine power losses, and variation of load conditions. A nonlinear vehicle powertrain model has been used in the development of the vehicle simulator. The effectiveness of the proposed scheme has been tested through experiments.

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This paper is concerned with attitude estimation using low cost, small-sized accelerometers and gyroscopes. A two step extended Kalman filter is proposed, which adaptively compensates external acceleration. External acceleration is the main source of estimation error. In the proposed filter, direction of external acceleration is estimated. According to the estimated direction, the accelerometer measurement covariance matrix of the two step extended Kalman filter is adjusted. The proposed algorithm is verified through experiments.

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Active noise control (ANC)-based systems provide good low-frequency noise attenuation by destructive interference between the secondary signal from an acoustic actuator (speaker) and the primary noise of the acoustic field (duct). A novel secondary-path model that described by two cascaded transfer functions and two disturbances for speaker-duct systems is first developed in this study. One disturbance is imposed on face velocity of actuator speaker that is usually ignored in ANC systems while the other is on sound pressure at a given location in the duct. The transfer functions are identified with measurements from a developed velocity sensor and a microphone, respectively. A combined design of ANC and face velocity control (FVC) based on the identified secondary-path model is further proposed to set up an adaptive feedback ANC/FVC controller with a modified filtered-X recursive least square (FXRLS) algorithm to update controller coefficients to reduce noise levels near microphone location. Results of experiments show that the adaptive feedback ANC/FVC controller has a noise reduction performance of ∼27-46dB for noise at a frequency between 100-200Hz, as compared with ∼10-35dB for that of the conventional feedback ANC design. Furthermore, the adaptive feedback controller reveals a good capability to reduce the noise level for time-varying noise of a frequency sweeping from 100 to 200Hz. Our data demonstrate a substantial improvement in the low-frequency noise attenuation using the developed controller that includes commonly overlooked factors and support the feasibility of our proposed approach in practices.

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This paper presents a control scheme of pneumatic servo systems for practical use, in which a two-layer neural network is used to construct the inverse system of the plant, and disturbance to the plant is estimated. The influence of the disturbance is eliminated by subtracting the estimated disturbance from the output of the controller. To improve the learning ability of the NN, σ modification method, which is one of the robust parameter adjusting methods of the robust adaptive control, is introduced. To confirm the effectiveness of the proposed control scheme, experiments using an existent pneumatic servo system were conducted. The experimental results showed that the external force was estimated well by the disturbance estimation mechanism, and the influence of the external force to the plant output was eliminated immediately after the external force was applied. In addition, high-speed learning of NN could be realized using the switching σ modification method.

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Synchronous control of mutual position for two vertical-type pneumatic servo systems is discussed for practical use in this study. In the proposed control system, a fuzzy controller is used in each pneumatic servo system so that the output of each plant can follow the reference input. A PD controller is introduced to realize the synchronization of both pneumatic servo systems, in which the outputs from this controller are the inputs for revision to both plants. A fuzzy virtual reference generator that can adjust the reference input to both fuzzy controllers adaptively by fuzzy rules is constructed to improve the transient performances of both axes. In addition, the adjustment controller produces a representative value of both cylinder outputs, which is used to synthesize the inputs to the fuzzy virtual reference generator, in order to reach a compromise between the follow-up ability to the reference input in each axis and synchronization of both axes. The applicability of the proposed method is confirmed by experiments using two existent vertical-type pneumatic servo systems.

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Unskillful operation and rough handling of conventional colonoscope, especially at the sigmoid colon, may lead to perforation or splitting the colon wall. Thus, it is crucial to develop autonomous or semi-autonomous colonoscopes that do not require physical force by the doctors for their motions. In this paper, we report the design and development of a colonoscopic robot system that has a locomotive function based on inchworm-like motion, with a hollow body and a steering system that consists of three pneumatic bellows of 7mm diameter, each located 120° apart from the others at the head part. The steering device can bend up to approximately 90°. In order to evaluate the performance of the colonoscopic robot, in-vitro tests and in-vivo tests were carried out. The experimental results show the feasibility of the prototype colonoscopic robot being used for diagnosis and treatments in colon.

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In this paper, sensitivity of the natural frequencies to the drive system design parameters is analytically investigated. Taking advantage of the highly structured natural frequency and vibration mode properties of the toroidal drive coming from its cyclic symmetry, simple formulae are obtained to calculate eigensensitivities. The general eigensensitivity relations for every natural frequency are formulated and applied to the three classes of different vibration modes. Then, sensitivity of the natural frequency to system parameters are discussed for different modes, respectively. The main influencing factors and their effects on sensitivity of the natural frequency are analyzed systematically.

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In this paper, the problem of asymptotic stability analysis for a class of linear large-scale systems with time delay in the state of each subsystem as well as in the interconnections is addressed in detail. By utilizing a model transformation and the Lyapunov stability theory, a delay-dependent criterion for stability analysis of the systems is derived in terms of some certain linear matrix inequalities (LMIs). A numerical example is given to illustrate that the proposed result is effective.

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This paper presents a method to coordinate an uncalibrated visuo-motor system in a 3D space. In order to handle spaces occluded by obstacles, a 3-camera system and two related self-organizing maps (SOMs) are employed. The self-organizing maps are directly connected to the camera system and are trained to perform position control. Based on the visibility of targets given in the workspace, an appropriate map is adopted. The maps determine the joint angles of the manipulator which make the end effector reach the targets precisely, and make the manipulator take obstacle-free poses. The proposed learning method ensures that the manipulator moves smoothly and consistently in whole workspace even though we use two maps to control it. In our visuo-motor system, neither any priori knowledge about the manipulator nor the camera parameters is required. In addition, the system is robust to change in its geometry. Simulation results are presented to demonstrate the effectiveness of the proposed method and the robustness of the system.

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This study was aimed to investigate the cross-sectional shape of mesenteric arterioles at branching, using confocal laser microscopy. Wistar rats (8 weeks, male) were anesthetized with thiobutabarbital sodium. Blood flow and microvascular network in the mesentery were observed using video microscopy. The rat intestine with mesentery was extracted and the intestinal vasculature was perfused with Krebs-Ringer and then fixed with paraformaldehyde under a static pressure of 100mmHg. A section of mesentery was isolated from the intestine, and spread up to the in vivo geometry based on the intravital microscopic observation. The mesentery section was stained with tetramethyl rhodamine isothiocyanate (TRITC)-phalloidin. The samples were observed under a confocal laser microscope. The cross-sectional image was re-sliced to measure the cross-sectional area and major/minor axes of the best fitting ellipse. The aspect ratio was defined in terms of the minor/major diameter ratio. The extended focus image of mesenteric arterioles showed that the cross-sectional shape was not circular but elliptic-like. The cross-sectional area of the parent vessel decreased from proximal to distal positions. The mean aspect ratio of the parent vessel was approximately 0.5, while that of the branching vessel was approximately 0.8. The flattened shape and variation of the cross-sectional area of arterioles requires some correction of in vivo data of the two-dimensional mesenteric microvasculature obtained using intravital microscopy.

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The technology for Virtual Prototyping could be adopted to take the place of Physical Prototyping so that we could innovate, test and evaluate the products, thus shortening the circle of product development, decreasing its cost and enhancing up an enterprise’s competition. Aiming at the rupture on the base of the remote cylinder during the Plow working, first the plow’s virtual prototype was established by SolidWorks in a computer ; secondly in view of the structure characteristic of the base of the remote cylinder, it was analyzed in kinematics and dynamics, at last with the help of the dynamics simulation software DDM, the plow was simulated working in the field to find out which of the two motion types operating in the field made the plow load larger and to determine the corresponding time the load was larger, supplying the potent data for the optimum design of the plow in the future.

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In humanoid robotic system, many human-body motions such as walking, running, and jumping require large power. As one effort to achieve such high power-to-weight ratio, this paper proposes a new hip design using parallel kinematic chain involving redundant actuators. The kinematics for the hip mechanism is derived and a kinematic index to measure force transmission ratio is introduced. It is demonstrated through simulation that incorporation of redundant actuator into the hip mechanism enhances the power of the mechanism approximately 4 times of the minimum actuation. And the validity of the simulation result was verified through experimental works.

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Molluscan shell is a kind of natural composite with excellent fracture strength and fracture toughness, which can be attributed to its unique microstructures. Scanning electron microscope (SEM) observation shows that Clam shell is a bio-ceramic composite consisting of aragonite and organic materials. These aragonite and organic materials distribute in the shell in the form of layers parallel with the surface of the shell. The observation also shows that the aragonite layers contain numerous thin and long aragonite strips, which are dozens of nanometers in diameter and can be regarded as aragonite fibers. These aragonite fibers align in the layers with different orientations. A kind of particular helicoidal layup of these aragonite fibers is found. The maximal pull-out force of the helicoidal layup of the aragonite fibers is analyzed, which accounts for the high fracture toughness of the shell. A comparative experiment for the maximal pull-out forces of both the helicoidal and the 0° layups is conducted, which shows that the maximal pull-out force of the helicoidal layup is markedly larger than that of the conventional 0° layup.

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There are several methods to estimate the residual capacity of lead-acid batteries. Most of these methods are not able to precisely predict the amount of remaining capacity due to the battery aging effect. This paper presents a method using the electrochemistry theorem to analyze the electrode reaction resistance effect and to estimate the internal energy loss and the electrolyte specific gravity in batteries. Through a series of calculations, the state-of-charge of a lead-acid battery can be estimated. To validate the proposed algorithm, some experiments are conducted and the measured data is applied to the proposed method and two other methods for comparison. The experiment results prove that the proposed algorithm can accurately compute the state-of-charge of lead-acid batteries to a certain extend and can be used in real-time controls.

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