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Crankshaft three degrees of freedom use the same parallel micro-mechanical structure of the experimental designAbstract: Crankshaft in mechanical structure design of the small general has been replaced mechanical connection and extensive use. However, the wrong model will be reduced Crankshaft precision mechanical structure. In this paper, in order to get the correct model Crankshaft and design of a 3-DOF planar the same type of micro-mechanical structure. To that end, an initial analysis of kinematics including inverse kinematics, internal kinematics and coordination of the work of a fixed model has been raised. First of all, take into account a freedom Crankshaft cycle type, but FEM based on the simulation results is inconsistent with the analysis of the results. This is because small axial direction along the connecting rod extended to hinder the accuracy of the mechanical connection. To address this problem, including an additional sports bodies such as the prism connecting the two degree of freedom model Crankshaft has already begun to use some. According to this model, ensure the accuracy of the mechanical structure. Through simulation and test showed that the accuracy of this model is effective. This work emphasized the model Crankshaft Crankshaft guarantee the accuracy of the micro-mechanical structure tied to the use of great significance.IntroductionMicro-mechanical devices in many areas is a key and essential techniques, such as scanning electron microscopy, X-ray lithography, mask alignment and micro-machinery. Recently, a lot of Crankshaft on the use of micro-mechanical structure of the analysis and experimental research. The majority of previous studies (Moriyama 1, 2, such as Taniguchi, Tomita, etc. 3, 4, such as Ryu, Chang, etc. 5, 6 Peng, etc., etc. 10 - 13 ) is the freedom to use an arm for recycling Crankshaft, three degrees of freedom for Crankshaft spherical arm, and thus the production model. However, sometimes even a small total, will do Crankshaft linear motion. Some researchers believe that there is a Crankshaft additional degree of freedom. However, they ignored the model in the process of easy mobility, but also not to micro-mechanical structure in the correct use of the fixed model. This led to the failure of the implementation of micro-systems. Therefore, the focus of this work will be easy mobility is based on the analysis of the accuracy of model Crankshaft.Introduction of the campaign because of the number of independent variables were constrained, and these independent variables, in order to find the relevant links between objects must be clearly defined. Above formula can be adopted (1) to describe the type of M, N, L, respectively Fi j and that movement, freedom of space operations, the number of links, as well as linking of the number of mobile connections i freedom. Exercise also shows that the minimum functioning of the system. When M N bigger than the sport become redundant system.Figure 1 shows a Crankshaft have freedom of the three micro-mechanical structure. Usually, these systems can be Crankshaft rotary connector of the model. Outlined in Figure 2 of the model Crankshaft. If all Crankshaft have a degree of freedom, then the movement of the system are three degrees of freedom. However, in the past, based on such assumptions are the result of the failure of this model because of the inaccuracy of Crankshaft. On the other hand, if all are Crankshaft model of the rotary connector and prism of connections, then the campaign structure reached 12 degrees of freedom. Even if the limit of program analysis and theoretical analysis will enable the two degree of freedom model Crankshaft than one degree of freedom model Crankshaft more accurate results, but need 12 to control the operation of three degrees of freedom rather expensive. Therefore, not only the design of Crankshaft to campaign structure to a minimum, but also to ensure that the structure of precision machinery and sufficient working space.In this paper, we designed two types of Crankshaft. The first type used only a relative degree of freedom to produce thicker neck parts, as shown in Figure 2, this shows that the thickness of the hinge. The second type is used to produce two-DOF relatively thin neck parts. Therefore, the second Crankshaft is a freedom with the rotary connector and a freedom connected to the prism production model. If the system of each chain are two degrees of freedom by a hinge and a two degree of freedom of the hinge, then the campaign structure is 6. Therefore, this Crankshaft through six operating structure to operate.Papers content in the next there will be further development. The second part describes the structure of the system. Kinematic analysis and three campaigns campaign structure and six fixed structural system analysis model respectively in the third and fourth part of a demonstration. Part V describes the two comparative freedom and freedom of a Crankshaft precision simulation results, but also embodies the six recommended by the movement of the systems benefits. Correct the effectiveness of this model can be reflected through experiments. .the system structureThe text of the proposed three-DOF tied in the same mechanical structure is a working platform and composed of three chains, each chain has three Crankshaft, as shown in Figure 1. This mechanical link in the use of all the Crankshaft, and all are connected through the pressure of the movement and operation factors. February 2 chain of three intervals between 120 . This symmetrical structure reduced due to temperature differences and the impact of temperature imbalance. Each chain connecting the first and the third are at the bottom with the machines connected to a pressure campaign structure to operate the contrary. All the movement to promote structural connections of each round good sliding surface and rotation.In the example in Figure 2 a type Crankshaft. This rotational movement Crankshaft equivalent to the displacement of I2 and h () and. In the X direction of the linear motion distance of A (). . three campaign kinematic structure of the system In order to demonstrate a degree of freedom model of the movement of Crankshaft, we will be presented in Figure 3 of this three movement kinematics model of the system. All the previous model Crankshaft only one degree of freedom, and this system has three campaign structure. Passed the map can clearly understand this kinematic analysis.A first kinematics First kinematics connected to the output rate vector and vector rate independent of the connection. Below, G said Jacobian, the lower left-hand corner of G machinery that tied the hands of the chain of consecutive numbers. G top right hand corner and lower right corner of the symbols that were related or independent parameters. Gu (, j) and Gu (i, ) were expressed that a cylindrical j and i Pai Gu . Gu (i, j) Gu (i, j) element. i, j expressed that the first i-chain chain j consecutive rate perspective. The rate for each chain relations through the formula (4) to describe the formula (4) in the output rate vector and i consecutive rate vector angle chain were defined as u and i . Three in a row because of the chain have the same rate in the platform, there will be a formula (5) and the formula (6). If the three foundations of a connecting link of an independent, as far as this case, the selection of three each in the chain of Jacobian contrary to the first row constitutes a separate connections to the output vector and the velocity vector of relations, and this rate relations constitute a body, the text following formula (7) indicated, a = 112131 T iG u = iGu -1. Now, reverse the formula (7) in the relationship between the output of the first order for the kinematics of the system linked by formula (8) can understand that these Gua = Gau -1.B、a fixed model Assumptions used in Figure 1 Crankshaft only in the Z axis, a rotary movement, while neglecting the other direction on the transfer. Crankshaft can connect all being used as a spring, in the strength of the needs or the needs of start or bending moment (or compressed). Therefore, in order to calculate input to the operation of machinery, we must use the same output as a reference to obtain the analysis of the fixed model.Be fixed ontology of the i-chain can be written (9), including iKj said that the first paragraph i j-linked connections of fixed structure. In a state of equilibrium, the machinery of the potential energy storage can be used (10), which iG u said that contrary Jacobian and u make a fine replacement, can inversus iG u access. Kuu that fixed by the bulk of the operational space. Formula (10), we can see that the output can be fixed Ontology (11) said. According to the formula (11), an effective vector output attributed to the transfer of u, is defined as (12), which we should pay attention to is that when the system is symmetrical structure and the same location of the three chains have the same fixed link of the , Kuu is a diagonal. with six movable structure kinematic analysis system。. with six movable structure kinematic analysis systemWhen each of the link was considered Crankshaft Figure 3 (b) shown with two degrees of freedom, the movable structure is six. Records of each chain according to the first axis direction Crankshaft has extended an additional three-vector form of connectivity. Will be described below in the kinematic analysis of this situationA first kinematics Each of the chain, the center position (x, y) and the operating platform of the position were expressed as (13), (14), (15). Figure 3 of the length of the actual connectivity for Li1 said, the i-hi2 said that the chain of three-vector form of the transfer link, that link Iij of fixed length. Distinguish between the chain on each row between the first time kinematic output equation can be used (16) said. Because of three consecutive platform in the center of the chain have the same rate of the output vector, we have the formula (17), (18). Here, we think that every first and third chain of connections is independent of the connection. Therefore, a total of six separate connections. If rearranging (17), (18), then independent of the connection ( a) and the associated connectivity of ( p) by the relationship between the (19) was. To (19) Insert (16) in (20). Finally, the output of separate connections and the relationship between the rate adopted (21) available.B, on the contrary kinematics The platform is a central location (x, y) position and a point of , all tied location of the chain links are available. But because small and mobile (21) equal relations from (22) available. In the six movable structure system, a u scope than the large scale. Therefore, (22) to the contrary relations from (23) available, which add to the Gua pseudo-opposite decomposition Gua + said. This shows that the potential energy system will be kept to the minimum extent is the best split (22) for the conditions. K aa that an effective fixed ontology and six independent of the connection, see (24), which said that Kpp ontology and related fixed line connecting devices. Finally, the independent connectivity products and the transfer of related links from (25), (26) was.C, a fixed model And connecting independent subsidiary of the fixed link of the respective body languages (27), (28), which iKj expressed that the first i-j chain of fixed connections. Ontology compliance with the output (24) equal to the fixed body, expressed as (29), which Caa = K aa -1. Therefore, the effective output vector attributable to the u, defined as (30), = Kuu Cuu -1. .Simulation Test FEM analysis can be used to prove the feasibility of a fixed model. Given the inherent minimal transfer platform for the operation of power systems transfer vector formula can be adopted (12) or formula (30) calculated. In FEM environment, the force applied to real vector model. Eventually, by comparison, from the initial analysis model is the transfer of FEM model output displacement vector can be tested based on dynamic analysis of the feasibility of a fixed model.Working space in the x and y direction is 0 100 um, in the direction of 0 0.1 . FEM simulation test results in Figure 4 to can be seen in Figure 6. Variable structure has three micro-mechanical devices in order and all other direction have shown a serious mistake. On the other hand, with six of the variable structure in order micro-mechanical devices showed 5 to 10 per cent of the small mistakes, and in other aspects of performance are only some small mistakes negligible, therefore, have six variable structure System than three variable structure of the system of higher precision. .fixed-analysis testCrankshaft from nine developed a mechanical hand can produce a metal Machine. Six contrary piezo-actuator launched and put into use. Piezo-actuato diameter is 17.4 um. Machines in the x and y directions to the extent permitted by the 0 100 um, in the direction of 0 0.1 . In this part, we have done a number of simulation experiments to prove the validity of test results. These trials are designed to simulate and forecast through fixed, the machine proved developed operational trends and the development of fixed value. Figure 8 shows the experimental operation. In Figure 9 describes in more detail. Experimental estimates will be operational in fixed below. A cylindrical rod link in the system of six sports centre. A level Hengmu links in the top rod, which is used to measure root Hengmu fixed the rotation. Shoring success is a central part of the operation through a PICOMOTOR, terminal operations through LVDT to measure the displacement of. Engine installed in manipulator links at the bottom of the F / T for measurement in the x and y directions can be fixed on the distribution of accurate information to estimate the strength, and this information can be passed force F / T measurement of the reaction to estimate.Through the promotion of standards and measurement Hengmu freedom for the three rotating mechanical devices and the rotation axis to measure rotation fixed. Figure 10 shows the results. Slope of three degrees of freedom in the mechanical device in each direction on fixed. Observation showed that in the x and y directions are identical to the fixed This proves that the previous 9 reported the results of the analysis. From the test and simulation of workable get stuck in Table 1 lists, which kxx, kyy, k that tilt terminology kww. As shown in Figure 1, simulation and test results between about 30% of the theoretical error rate. It is not perfect, but since the shooting parameters of the micro-system, it is sensitive to the satisfaction of people. The error rate in part because of manufacturing errors, and the other was partly due to measurement errors caused. We believe that these errors can be improved through the design and the actual design of Calibration technology improvements to make up for.conclusions Crankshaft inaccurate model can not ensure that the operation of micro-mechanical precision. In this paper, bearing in mind the precise Crankshaft production model, a 3-DOF planar parallel micro-mechanical devices is recommended. We have already pointed out that the article begins with a three movable structure of 3-DOF planar parallel micro-mechanical model can not ensure that the location of system accuracy. On the other hand, with six movable structure of the show had a very good position accuracy. We demonstrate this simulation experiments to confirm the validity of test results. We concluded that the right model can improve the micro-mechanical design of location accuracy. The device is expected in the SEM, X-ray lithography, mask alignment and micro-mechanical technology, as well as other similar effective use.
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