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This paper presents an algorithm to identify the handwritten and the printed texts among document images. The characteristic of stroke thickness is used and a kind of calculating method is designed for this feature. The proposed method, which is clearly defined and easily realized, calculates the stroke thickness feature by counting edge pixels in a neighborhood. Document images are generally divided into text lines or characters. However, the line and the character are not conducive to the judgment between handwritten and printed text distinction. The line is too rough and the character is too small. Using the stroke thickness characteristics, combined with layout analysis, the text line in the document image is further divided into the area of uniform thickness. This kind of area is more detailed than text line and larger than a single character. So more stable features can be extracted from it. Last, the features of these regions are divided by using SVM. The proposed algorithm obtained better performance in the document image database including handwritten and printed texts.

Increasingly freeform prototypes and molds for high volume replication are being manufactured using diamond machining. Nevertheless, stroke limits of established fast tools require using time consuming slow tool processes reducing productivity. Further, freeform measurements require high efforts. The UPC 400 overcomes these limitations. Utilizing a fast tool with an industry leading stroke length permits machining a wide range of freeform optics in the shortest time while increasing productivity and accuracy. Machine integrated, optical metrology allows for comfortable freeform measurements without having to remove the optic. Besides precise measurements, this enables corrective machining to create surfaces of the highest quality.

Circular dielectric electro-active polymer (DEAP) membrane actuators are easy to manufacture and therefore can be uniquely designed to perform optimally for specific applications. The performance of these actuators is naturally dependent on the materials used, and also dictated by the specific geometry of the circular design. For a given overall actuator size, changing their internal geometry will directly change the force and stroke output. In addition the DEAP technology itself is a promising technology for constructing lightweight, cost and energy efficient sensor and actuator systems. Thus, several potential applications like pressure sensors, pumps, valves, micro-positioners and loudspeakers were already proposed. The circular DEAP membrane actuators used in this study consist of a silicone based elastomer, carbon ink based electrodes, and are held together with a stiff frame. Experimentally collected force-displacement curves for these actuators can be used to determine force and stroke output of the actuators as described by Hodgins et al. in. This work presents an efficient method to predict these force-displacement plots and thus stroke and force output for different actuator geometries. These results than can be used to adapt the actuator geometry to the needs of a specific application with its particular force and stroke requirements. The prediction method is based on an average stress-stretch calculation for training samples. The calculated stress-stretch data is then geometry independent and can be used to predict desired geometry dependent force-displacement data for stroke and force output analysis.

This paper presents an experimentally verified static three-dimensional model for core free tubular dielectric elastomer actuators with anisotropic compliant metal electrodes. Due to the anisotropy of the electrodes, the performance (force versus voltage, force versus stroke, and stroke versus voltage) of the actuators depends strongly on their geometry. Based on the three-dimensional model, the performance of the actuators is optimized by means of the length of the axes of their inner elliptical cross section and their wall thickness.

This paper proposes a method for the design of governor foot mechanism on high-speed printing press. According to the technological conditions, an optimal design model is presented to achieve the minimum deviation between the desired and actual track points. The physical dimensions of the linkages and the angular stroke of the driven cam can be gained by solving the presented optimum model.Then the driven cam’s profile is calculated. The effectiveness of the proposed method is proved through an illustrative design example of a governor foot mechanism for high-speed operation . Keywords: Cam-Linkage Mechanisms, Optimum Design, Governor Foot Mechanism, Printing Press. 1. INTRODUCTION In high-speed offset press, the feed system has the task of picking up the sheets from the feed pile, separating them via suction head, conveying them to the feed table, and aligning them at the feed guides [1]. The suitable design of this feed system is very important to ensure the precision of overprint and the quality of the press products, especially in high-speed operation. The governor foot mechanism is one of the key components of the suction head, which is used to separate the sheets and convey them to the feed table one by one. The suction head, also called feeder, has another two main components besides governor foot: lifting sucker and forwarding sucker. Each individual sheet is separated via the well coordinating of them: (1) the lifting sucker lifts the first sheet at the top of the feed pile; (2) the governor foot steps on the top surface of the rest of the feed pile, then its blower blows to help the lifting sucker separate the first sh eet completely; (3) the forwarding sucker moves back, gets the sheet from the lifting sucker, and conveys it to the feed table, (4) the governor foot makes way to the lifting sucker, the latter moves down to suck the second sheet up. Via these repeated technological actions, the sheets are separated and conveyed to the feed table one by one. In the process of stepping on the surface of the feed pile, the governor foot also has task of detecting the height of the pile, a signal will be sent from time to time, and the feed pile will be lifted accordingly to keep its height and en sure the successive separating of sh eets and normal printing process. It is obvious that the structural design, accuracy of manufacturing, the kinetic and dynamic characteristic of the suction head will affect the performance of the printing press in many aspects, such as the printing speed, the precision of overprint and of paper sheet changeover, and the quality of the press products, etc [1]. Hence, as one of the key components of the feeder, suitable design is needed for the governor foot mechanism. Cam-linkage mechanisms are widely used to meet the requir ements of the governor foot used in the feed system on printing press. As shown in Fig.1, is a diagrammatic sketch of a widely used design scheme of the governor foot mechanism. When the driven cam rotates, its follower will swing up and down around a fixed central pointA , and through the planar linkage mechanism, the link foot F P will accordingly complete a series of movements such as stepping on the feed pile, staying for a while and blowing to help the lifting sucker separate the sheet at the top of the pile, and leaving away to let the lifting sucker separate another sheet, etc. This paper proposes a method to solve this kind of design problem. In section 2, we first explain the requirements to the trajectory path of the foot link F P , and then present an optimum model, which is used to achieve the mi nimum deviations between the desired and actual track points of the foot link, to synthesize the linkages’ dimensions and the angular stroke of the driven cam. In section 3, we present the parametric expressions for the driven cam profile. An illustrative design example based on the proposed method is given in section 4, and the effectiveness of the design method was proved by the calculation results. This proposed

This paper presents a linear-rotary micr o-stage that can generate motions along and about the Z-axis using piezoelectric elements (PZTs). The small stroke of a PZT is extended by repeating the PZT motions based on a mechanism of impact friction drive. The friction drive mechanism has a simple driving unit, which only consists of a PZT element and a friction element. The moving element of th e stage, which is a steel cylinder, is supported and actuated by a driving unit, which consists of two PZTs and a friction component made by permanent magnet. The magnetic force is employed for holding the moving element and stabilizing the driving condition. The dimension of the stage is 7.0 mm × 8.8 mm × 7.5 mm. The moving ranges of the stage are about 5.0 mm in the Z-direction and 360 degrees in the z -direction, respectively. The maximum moving speeds are approximately 30 mm/s and 84 rpm in the two directions, respectively. Keywords: micro-stage, two-axis, rotary, linear, pr ecision positioning, PZT, friction drive

Compact actuation that is integrated into a structure's material system has the potential to provide rapid structural reconfiguration while reducing weight. The effect of scale (diameter, overall length and segment length) on the performance of cylindrical fiber-reinforced McKibben-like Rubber Muscle Actuators (RMA) was investigated. An "activation" pressure was observed for all actuators at a value that depended upon the actuation construction. Upon pressurization past the activation threshold, the overall force, stroke, and work capacity increased with increasing actuation length and diameter. The actuation force per unit RMA cross-sectional area was predicted, and experimentally observed, to be roughly constant after activation. By segmenting a longer actuator, a larger contraction and lower actuation force could be achieved. Though actuation forces decreased as actuator diameter and length decreased, the force per unit actuator volume was shown to increase with decreasing diameter including a roughly 4-fold increase in force/volume between the 0.5" and 0.05" actuators. However, due to the small amount of total contraction for the smaller diameter actuators, the relative work per actuation volume was decreased by roughly 35% in comparing those same actuators. Thus, small diameter RMAs have great potential to provide needed linear actuation force within adaptive material systems.

A bidirectional magnetostrictive actuator with millimeter stroke and a blocked force of few tens of Newtons has been developed based on a Terfenol-D driver and a simple hydraulic magnification stage. The actuator is compared with an electrodynamic actuator used in active powertrain mounts in terms of electrical power consumption, frequency bandwidth, and spectral content of the response. The measurements show that the actuator has a flat free-displacement and blocked-force response up to 200 Hz, suggesting a significantly broader frequency bandwidth than commercial electromagnetic actuators while drawing comparable amounts of power.

In this paper, PMN-PT single crystal piezoelectric stack actuators and flextensional actuators were designed, prototyped and characterized for space optics applications. Single crystal stack actuators with footprint of 10 mm x10 mm and the height of 50 mm were assembled using 10 mm x10mm x0.15mm PMN-PT plates. These actuators showed stroke > 65 - 85 microns at 150 V at room temperature, and > 30 microns stroke at 77 K. Flextensional actuators with dimension of 10mm x 5 mm x 7.6 mm showed stroke of >50 microns at room temperature at driving voltage of 150 V. A flextensional stack actuator with dimension of 10 mm x 5 mm x 47 mm showed stroke of approx. 285 microns at 150 V at room temperature and > 100 microns at 77K under driving of 150 V should be expected. The large cryogenic stroke and high precision of these actuators are promising for cryogenic optics applications.

We report on test results on the delay line system for the MRO Interferometer, currently under construction in Cambridge, UK. The delay lines are designed to provide 380 metres of vacuum path delay in a single stage, offering rapid star-to-star slews, high throughput and high transmitted wavefront quality. Details of the final design adopted for these delay lines are presented, together with lessons learnt from successful performance tests of the full-scale prototype trolley in a 20-metre long vacuum test rig. Delivery of the first production trolley is expected in New Mexico in early 2009.

Devices based on SOI technology are subject to bow due to residual stress induced by the buried oxide. We have designed and fabricated a compact tunable piston tip-tilt mirror device in which the shape and the arrangement of the suspension beams result in both a reduced stress in the suspension beams and an optically flat mirror. The piston tip-tilt mirror is characterized by an accurate vertical displacement of up to 18 mm @ 80 V with good repeatability, and a tip-tilt of up to 2 mrad @ 50 V.

An important technological barrier in the development of microrobotic systems is the lack of compact sensor-actuator systems. This paper presents a piston-cylinder fluidic microactuator with an integrated inductive position sensor. Such positioning systems offer great opportunities for all devices that need to control a large number of degrees of freedom in a restricted volume. The main advantage of fluidic actuators is their high force and power density at microscale. The outside diameter of the actuator developed in this research is 1.3 mm and the length is 15 mm. The stroke is 12 mm, and the actuation force is more than 0.4 N at a supply pressure of 550 kPa. The position sensor consists of two coils wound around the cylinder of the actuator. The measurement principle is based on the change in coupling factor between the coils as the piston moves in the actuator. The sensor is extremely small since one layer of 25 μm copper wire is sufficient to achieve an accuracy of 10 μm over the total stroke. Measurements showed that the actuator achieves a positioning accuracy of 20 μm in closed loop control.

A closed-loop sensorless stroke control system for a linear compressor has been designed. the motor parameters are identified as a function of the piston position and the motor current. they are stored in rom table and used later for the accurate estimation of piston position. some experimental results are given in order to show the feasibility of the proposed control schemes for linear compressors.

Shape memory polymers (SMPs) are attracting a great deal of interest in the scientific community for their use in applications ranging from light weight structures in space to micro-actuators in MEMS devices. These relatively new materials can be formed into a primary shape, reformed into a stable secondary shape, and then controllably actuated to recover their primary shape. The first part of this presentation will be a brief review of the types of polymeric structures which give rise to shape memory behavior in the context of new shape memory polymers with highly regular network structures recently developed at LLNL for biomedical devices. These new urethane SMPs have improved optical and physical properties relative to commercial SMPs, including improved clarity, high actuation force, and sharper actuation transition. In the second part of the presentation we discuss the development of SMP based devices for mechanically removing neurovascular occlusions which result in ischemic stroke. These devices are delivered to the site of the occlusion in compressed form, are pushed through the occlusion, actuated (usually optically) to take on an expanded conformation, and then used to dislodge and grip the thrombus while it is withdrawn through the catheter.

We present herein a new out-of-plane MEMS actuator array. Previously, we developed out-of-plane MEMS actuators having a 180-μm stroke in the out-of-plane direction. However, the maximum output force, scale of integration and density of integration were limited to 0.087 mN, four actuators and 4 mm 2 /actuator, respectively. In the present paper, we propose a new calculation method by which to estimate the maximum output force and driving voltage according to conventional mechanics of materials. The improved shape of the actuator was derived using this method, and the maximum output force was increased up to 0.83 mN, which is approximately 10 times larger than that of the previous actuator. The scale and density of integration were improved via multilayer interconnection up to 100 actuators (25 times) and 1 mm 2 /actuator (a four-fold increase), respectively. In addition, we examined the driving behavior of the actuator array.

Conventional translation micromirrors for adaptive optics use attractive electrostatic force and therefore have two limitations: 1) the stroke is limited to less than one third of the initial gap distance between the mirror plate and the substrate. Normally the stroke is in the range of submicrometers; 2) stiction happens during operation. A novel translation micromirror, which uses a repulsive electrostatic force, is presented in this paper. This novel translation micromirror completely overcomes the limitations associated with conventional translation micromirrors and its stroke is not limited by the initial gap distance between the mirror plate and the substrate and therefore is able to achieve a much larger vertical stroke to modulate lights over a wider spectrum than that achieved by conventional translation micromirrors. The novel translation micromirror has no stiction problem and is highly compatible with mature surface micromachining technology. An analytical model is derived for the novel translation micromirror and prototypes are fabricated. The prototype of the novel translation micromirror, which is deliberately not optimized so it could be fabricated using MUMPS, achieved a vertical stroke of 1.75μm using a driving voltage of 50 volts, which is three times the stroke of conventional MUMPS translation micromirrors. It is expected that if standard surface micromachining is used instead of MUMPs, the design of the novel translation micromirror can be optimized and a much larger vertical stroke can be achieved.

A new actuator design is introduced, which utilizes a pair of matching piezoelectric stack elements within the actuator housing. The stack elements are utilized in a mechanically opposing configuration and are electrically operated out-of-phase. Conventional piezoelectric stack actuators usually incorporate a compressive preload mechanism to protect the stack from tensile stresses. A common preload method is to incorporate a mechanical spring in parallel with the stack. However, the mechanical spring reduces the free stroke capabilities of the stack actuator. To demonstrate the performance advantages of the new concept, an analytical and experimental comparison study is conducted. The dual stack actuator is compared with two conventional internally preloaded single stack actuators in a parallel configuration, thus both actuator configurations are utilizing equivalent volumes of the piezoelectric material. The analysis indicates the dual stack actuator produces greater free stroke, output energy, and energy efficiency than two parallel single stack actuators. For experimental evaluations, a dual stack actuator and an internally preloaded single stack actuator are fabricated using the same materials, similar construction techniques, and the same piezoelectric stack elements. A testing procedure is formulated to determine the free stroke and blocked force of both actuators. Comparison of the experimental data reveals a number of performance advantages of the dual stack actuator over two traditional preloaded actuators in parallel: the free stroke is 1.3-1.2 times greater; the blocked force is 1.4-1.2 times greater; the output energy is 1.8-1.5 times greater; the specific output energy is 2.4-1.9 times greater; and the energy efficiency is 1.8-1.5 times greater.

Piezohydraulic actuation is the use of fluid to rectify the motion of a piezoelectric actuator for the purpose of overcoming the small stroke limitations of the material. In this work we study a closed piezohydraulic circuit that utilizes active valves to rectify the motion of a hydraulic end affector. A linear, lumped parameter model of the system is developed and correlated with experiments. Results demonstrate that the model accurately predicts the filtering of the piezoelectric motion caused by hydraulic compliance. Accurate results are also obtained for predicting the unidirectional motion of the cylinder when the active valves are phased with respect to the piezoelectric actuator. A time delay associated with the mechanical response of the valves is incorporated into the model to reflect the finite time required to open or close the valves. This time delay is found to be the primary limiting factor in achieving higher speed and greater power from the piezohydraulic unit. Experiments on the piezohydraulic unit demonstrate that blocked forces on the order of 100 N and unloaded velocities of 180micrometers /sec are achieved.

This paper reports the design of a piezoelectrically-driven microfabricated valve for high frequency control of large pressure fluid flows. The enabling concept of the valve is the ability to convert the small displacement of a piezoelectric element into a large valve cap stroke through the use of a hydraulic fluid, while maintaining high force capability. The current valve design, with operating frequency of 24 kHz and valve stroke of 40 micrometer, has been tailored for use in microhydraulic actuation and energy-harvesting devices, which require high-frequency regulation of approximately 1 ml/sec fluid flows across pressure differentials of 1-2 MPa.

This paper presents the design and preliminary test results of a piezoelectric stack (piezostack) driven leading-edge flap actuator. The actuator uses six commercially available piezostacks with a curved contact tip for force and stroke profile tailoring. Force requirements were calculated using a quasi-steady aerodynamic model. Stroke amplification is achieved through a single lever. Initial results show that the current prototype is not ready to achieve the desired stroke output, but potential problems are identified and action is being take to rectify these problems.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

A hybrid piezohydraulic pump is under development for smart structures applications. Structural control applications often require large force be delivered over a large displacement. Piezoelectric actuators produce a large force over a small displacement. This can be repeated many times per second. Step and repeat piezoelectric devices, such as inchworm motors, increase the power output of the actuators and have the potential to produce large forces and large displacements simultaneously. The piezohydraulic pump makes use of the step and repeat capability. The pump utilizes a piezoelectric stack actuator to drive a piston in a cylinder. The forward stroke pressurizes the hydraulic fluid in the cylinder and forces it out through a check valve. The reverse stroke draws fluid into the cylinder through a second check valve. The prototype pump has produced a working pressure of 6.9 MPa (1000 psi) and a flow rate of 45 ccm.© (1999) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

Force actuators used for vibration control, such as shakers and proof-mass actuators, typically use single-phase electromagnetic linear motors that have a range of travel limited to a few inches. For proof-mass actuators, the stroke limitation can be especially constraining because it also limits the force output of the actuator at low frequencies. To overcome this low output at low frequency, we have developed an inertial, long stroke, linear actuator (ILSLA). The ILSLA is built around a three-phase linear motor that is driven by a commutating amplifier to achieve strokes of almost unlimited length. Vibration control applications that can benefit from this technology include precision space structures and large- scale robots.

Optically accessible D.I Diesel engine with a rectangular combustion chamber was constructed to visualize the behavior of sprays and flames in the combustion chamber with close conditions of pressure and temperature of actual engine. The behaviors of sprays and flames in the combustion chamber at compression stroke and expansion stroke in accordance with operating conditions were photographed with high speed camera by Back Illumination Scattering Method and Schlieren method. With photographs taken by these methods, behavior of evaporating sprays and spray droplets, ignition points, the flame propagation were observed and analyzed at a time- and space-dependent fashion with image processor.© (1995) COPYRIGHT SPIE--The International Society for Optical Engineering. Downloading of the abstract is permitted for personal use only.

The possibility of concentrating all the transmitted energy into one spectral order is established for a triangular groove dielectric grating for which a thin layer of per fectly conducting metal is evaporated on the small facet. The reflected energy is then only equal to the Fresnel reflectance (i. e. " 4 ). When an antireflection coating is evaporated on the large facet the transmitted efficiency can reach 100 into the first order.