機械手機器人外文翻譯-水下機器人的理論和設計問題【中文3150字】【PDF+中文WORD】
機械手機器人外文翻譯-水下機器人的理論和設計問題【中文3150字】【PDF+中文WORD】,中文3150字,PDF+中文WORD,機械手,機器人,外文,翻譯,水下,理論,設計,問題,中文,3150,PDF,WORD
【中文3150字】
國際控制會議，儀器儀表和機電工程（CIM'07）
Johor Bahru，Johor,，Malaysia，5月28-29,2007
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水下機器人的理論和設計問題
Irfan Abd Rahman,Surina Mat Suboh, Mohd Rizal Arshad
馬來西亞理科大學
摘要
在本文中，我們將討論水下機械手設計的理論和實現面臨的問題。這是以前的研究人員在工作中提取的信息的方法。本文介紹了一些建模參數，這是通常包含在水下機器人的外觀設計，增加質量，增加科里奧利力，阻力和浮力。模擬所有這些參數使用MATLAB通過修改一些運行代碼，是由彼得·柯克通過他的機器人工具箱完成的。通過對一個土地基礎的設計和水下機械手的設計進行了比較， 作為水下機械手需要執行其工作添加參數，指出增加轉矩要求做出類似的運動關節鏈接。在本文中，我們使用了彪馬560配置，這作為我們的手動工具的機器人工具箱內部生成的。本文給出了提高和改進的下一個方向。?
1．介紹
探索海洋已經成為一個新興的研究領域，由于許多資源位于深海之下。深?？碧浇o人類帶來了不同的挑戰，因為人類不能夠承受一些嚴酷的條件，因此為了避免在深海中的人為因素干預，機器人的研究已進入深海。當前熱門的研究領域主要集中在AUV（自主水下載具）的開發和部署。AUV的一些應用程序能讓水下機器人操縱自己進入深海。這將消除人類被暴露在危險環境中的水下勘探,包括檢查。水下機器人配備了照相機來執行其檢查周圍覆蓋面積。預計水下AUV將在未來取代人類從事海洋探險，并在減小危險中起到至關重要的作用。
機械手的設計和應用是深入到另一個領域的研究,將使機器人復制人類的手臂和手的功能。各個實用的應用程序已被研究如擰緊裝配零件等。機械手的設計通常由它能夠執行或“操縱”本身的度數決定,或換句話說是DOF(自由度)。自由度是指機械手擁有的基本關節的數量。機械手的自由度數字越高意味著移動更加靈活。接頭可以分為兩種不同的類型：棱柱和回轉。柱狀關節使關節平移運動而轉動關節可以使關節做旋轉運動。
水下機器人機械手系統（UVMS）在機器人研究界得到普及，因為它提供了水下機器人更大的靈活性和更廣泛的應用。更多的應用程序使以前需要制導武器的人由更靈巧的機械手取代。操縱器能夠執行各種任務，如從海床，鉆床拿起對象，加入零件和零件的組裝都配備了水下機器人。由于這樣的事實，即它必須考慮水下存在的流體力學，更好的設計與使用現存的機械手是唯一可能的事。
水下機器人機械手系統在感興趣的研究者中構成了不同的挑戰。這包括增加的質量，浮力，阻力和摩擦。由于從流體動力學添加效應，這將改變機械手的動力學。
這篇文章的目的是討論一些包括裝備水下車輛與機械手的設計問題。本文著重給出了對五個方面的設計標準：自由度、工作區范圍、末端執行器的最大速度和可重復性、操縱器的精度。在本文中,我們進行了模擬以顯示水下機械手和表面機械手的區別，包括水動力效應的機械手的動態功能。在這個測試中我們使用6自由度的轉動關節對配置的所有復制末端執行器進行定位。所有的連接參數被正確地指定，如力矩的慣性張量、重力齒輪比和摩擦。
在參數模擬時改變質量變化的參數，也可聯系浮力變化。利用機器人工具箱函數對MATLAB的工作區所有的模擬進行了研究。比較著重于轉矩要求，以實現水下和表面機械手操作之間的位置的分配。通過使用逆動態算法牛頓歐拉法的遞歸得到的扭矩，基于關節的位置、速度和加速度計算出扭矩。通過公正的分析和模擬受到流體動力學影響的水下機械手的運動結論變化的多少，從而保證在水下機械手的設計中對這一因素有足夠的考慮。通過利用電源模擬，我們能夠觀察到由于流體力學，我們的扭矩值等某些參數的變化的效果。這將確保機械手一個更好的設計。
2.?設計考慮
水下機器人機械手系統在感興趣的研究者中構成了不同的挑戰是由于，事實上，它研究的流體力學存在于水下。在本文中注重的是對五個方面的設計：自由度、工作區范圍內、承載能力、末端器最大速度和重復性、操縱器準確性。除此之外，了解動態運動的機械手的運動學是非常重要的。運動學是不考慮導致運動的力的研究。機械手的運動涉及幾何的研究和基于時間的運動屬性，特別是如何移動各個環節，并隨著時間的推移相互對應。在機械手的路徑規劃中，更多的是使用逆運動學的解決方案，使關節角度達到指定的末端執行器的所需位置。該解決方案是關于Denavit-Hartenberg表示法確定聯合鏈接參數。機械手動力學涉及運動方程，機械手動作響應扭矩應用的執行機構或外力。N-軸運動的操縱器一般方程為：
如果附加質量、浮力、液壓阻力和摩擦水下機械手的動態參數都會增加，當機器人在水下移動時，額外的力和力矩系數也會添加，圍繞機器人的流體必然會促進機器人有效質量變化。這些系數是額外的（虛擬）的質量，由于力系數線性和角加速度增加如轉動慣量和交叉耦合項等。水下具有n關節的機械手的運動方程如下：
其中?q是關節角的位置，M是慣性矩陣，C為科氏力，離心力，G代表重力包括浮力的影響，F是摩擦條件，D是機械手相對海流和海浪的速度造成的液壓阻力，τ是向量，這實際上是應用關節力矩控制輸入。
2.1?DOF（自由度）
操縱器可以在3-D空間中執行的獨立的運動的的數目被稱為自由度的數量。機械手臂可以提供多個自由度,下面的圖1展示的是先進的卡夫遙控機器人捕食者7。機械臂基本上有兩種類型的運動：平移和旋轉。即表示沿三個垂直軸直線運動，通過三軸指定主體的位置和角的旋轉運動及繞主體的旋轉方向。自由度由該機械手的任務決定。一個常見的設計策略是基于三自由度實現任意位置，并添加在一個3自由度球面手腕上以實現任意方向的運動。手頭的任務通常并不需要一個完整的6 - DOF，例如：任務對象表現出對稱時，或在沒有工作區中的障礙，或簡單的任務時，涉及有限的運動方向。很顯然設計最低自由度的操縱實現任務是最佳的。這將減少成本、簡化分析。大部分的商業水下機器人在水下航行器做安裝操作。其中一些只設計很少的自由度，因為車輛本身也有它自己的自由度。然而，JASON有一個通用的六自由度機械手。圖2顯示了JASON的機械臂。
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圖1：卡夫?遙操作機器人系統?“捕食者”-7
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圖2：JASON的機械臂
2.2工作范圍
一個機械手的工作空間被定義為一個操縱器的工作區中的空間體積，在該空間機械手是能夠找到它的末端。因此，在這種分析中工作區是指在周圍的水下。有時需要考慮工作區的形狀?！C械手的工作空間的特征是機械接頭限制除了配置、鏈接長度和數量以外的機械手的自由度。被指定工作區存在或不存在的解決方案屬于逆運動學問題。通過原點的端部區域，可以達到至少一個方向的效應子被稱為可達工作空間（RWS）。如果工作空間中的一個點只在一個方向可以達到，末端器的可操作性是非常差，只用一個固定的方向是不可能符合任何實際工作要求的。因此，它必須找到可以達到在一個以上的方向的點工作區。末端可以達到每點所有的方向的空間被稱為靈巧工作區（DWS），如果一個特定的機械手可確定構成，沒有解決方案，這種配置被稱為“奇異”。分為奇異性的邊界和或內部的奇點。對應于這些奇異點代表在工作區中的奇異表面的表面補丁。因為奇異的表面是移動操縱器的不可能的前端沿，無論選擇哪個關節率，它們是操作期間應被避免。任何位于一個奇異表面上的點都將具有零可操作性。
2.3承載能力
電動機的大小、關節和鏈接的結構完整性決定了機器人的負載。對于相同的結構完整水平，作為工作區的體積增大，有效載荷能力會下降。
2.4?末端執行器的最大速度
機械手比單純自動化或人工可以實現更快、更可行地完成任務。周期時間是達到一個完整的移動花費的時間，是一個與速度有關的函數，而且還可能與加速在加速和減速階段有關。因此，加速能力也是重要的。
2.5可重復性和準確性
這是任何機器人的關鍵性能之一。構建具有高精度和重復性的機器人是昂貴的，需要更嚴格的鏈接，更嚴格的公差，位置傳感，建模等。目標應該是任務所需要的最小精度和可重復性。外部傳感，特別是力感應，在很多減少所需的水平或準確性的任務中是一種有效手段。這也仍然是一個活躍的研究領域。
Theory and Design Issues of Underwater Manipulator Irfan Abd Rahman,Surina Mat Suboh,Mohd Rizal Arshad Univesiti Sains Malaysia ,sue_,rizaleng.usm.my Abstract In this paper we discuss the theory and implementation issue that is faced by underwater manipulators designers.It is collective information and method that was extracted from work by previous researchers.The paper presented some of the modeling parameters which is normally included in the underwater robotic designs which are add mass,added corriolis,drag force and buoyancy.Simulations of all these parameters were run using the MATLAB by modifying some of the code which was created by Peter Corke through his robotic toolbox.A comparison between land based design and underwater manipulator design were done which indicates an increase in the torque required to make similar movement in the link joints due to the added parameters as the manipulator perform its work underwater.In this paper we have used the PUMA 560 configuration which is generated inside the robotic toolbox as our manipulator tool.The paper then concludes with next direction of the project and improvement.1.Introduction Oceanic exploration has become an emerging field of research due to many human resources which is located beneath the deep sea.Deep sea exploration poses a different challenge to human being since we are not able to withstand the harsh condition that it poses.Therefore robotic research has come into place in order to prevent human intervention in the deep sea.Current field of intense research focuses on the development and deployment of AUV(Autonomous Underwater Vehicle)which is able to maneuver itself into the deep ocean.This will remove human from being exposed to the hazardous environment during underwater exploration.Some of the application of the AUV includes inspection whereby the AUV is equipped with camera to perform its duty to inspect the surrounding of the required area.Underwater AUV are expected to play a vital role in the future in replacing humans from the danger of ocean exploration.Manipulator design and application is another area of intense research which will enable robot to replicate the function of the human arms and hands.Various applications have been researched such as the use for placing and screwing assembly parts.Manipulator design are normally governs by the number of degrees that it is able to perform or manipulate itself or in other words DOF(degrees of freedom).Degree of freedom refers basically to the number of joints that the manipulator possesses.The higher the number of DOF means that the manipulator is more flexible to move around.Joints can be classified into two different types which are the prismatic and revolute.Prismatic joints are joints that are making translational motion while revolute joints are joints which are able to make rotational motion.Underwater Vehicle Manipulator System(UVMS)has gain popularity in the robotic research community as it offers underwater robots more flexibility and wider range of application.More application which previously requires the guided arms of human is being replaced by the more dexterous robotic manipulator.Underwater vehicle which are equipped with manipulator are able to perform various task such as picking up object from the ocean bed,drilling,joining parts and even part assembly.This is only possible with the use of better design existed in the manipulator.Underwater Vehicle Manipulator System poses a different challenge upon interested researcher due to the fact that it has to take the consideration of the hydrodynamics that existed underwater.This includes the added mass,buoyancy,drag and friction.This will change the dynamics of the manipulator due to the added effect from the hydrodynamics.The objective of this paper is to discuss some of the design consideration that has to be included when equipping underwater vehicle with manipulator.In this paper attention are given towards five aspects of the design criteria which are the DOF,workspace extent,end effector maximum speed and repeatability and accuracy of the manipulator.In this paper we have International Conference on Control,Instrumentation and Mechatronics Engineering(CIM07),Johor Bahru,Johor,Malaysia,May 28-29,2007725conducted simulation to show the difference between the underwater manipulator and surface manipulator by including the hydrodynamic effect in the dynamic function of the manipulator.For this test we have use 6 DOF of PUMA configuration with all revolute joints to replicate the end effector positioning.All the links parameters are properly specified such as the moment of inertia tensor,gravity the gear ratio and friction.Among parameters that were simulated are the change mass change in the link parameters and also the buoyancy change.All the simulation was conducted in the MATLAB workspace by utilizing the robotic toolbox function.The comparison focuses on the torque requirement in order to achieve the assigned position between manipulator which operates underwater and also the surface.The torque is obtained by using the inverse dynamic algorithm of recursive newton euler method,which calculates the torque based on the position,velocity and acceleration of the joints.From the analysis and simulation a fair conclusion was made indicating how much the change of the hydrodynamic will impact the movement of the underwater manipulator and thus will ensure enough consideration given towards this factor in the underwater manipulator design.By utilizing the power of simulation we are able to observe the effect on our torque value as we vary certain parameters in the hydrodynamics.This will ensure a better design of the manipulator.2.Design Consideration Underwater Vehicle Manipulator System poses a different challenge upon interested researcher due to the fact that it has to take the consideration of the hydrodynamics that existed underwater.In this paper attention are given towards five aspects of the design criteria which are degree of freedom(DOF),workspace extent,load carrying capacity,end-effector maximum speed and the repeatability and accuracy of the manipulator are needed to be considered.Besides that,it is very important to know about the kinematics and dynamic motion of manipulator.Kinematics is a study of motion without regard to the forces which cause it.The kinematics of manipulators involves the study of the geometric and time based properties of the motion,and in particular how the various links move with respect to one another and with time.Of more use in manipulator path planning is the inverse kinematic solution which gives the joint angles required to reach the specified end-effector position.The solution is regarding to the Denavit-Hartenberg notation to identifying joint-link parameters.Manipulator dynamics is concerned with the equations of motion,the way in which the manipulator moves in response to torques applied by the actuators,or external forces.The general equation of motion for an n-axis manipulator are given by =M(q,q)+C(q,q)q+F(q)+G(q)If added mass,buoyancy,hydraulic drag and friction are added on the underwater manipulator dynamics.As the robot moves underwater,additional force and moment coefficients are added to account for the effective mass of the fluid that surrounds the robot and must be accelerated with the robot.These coefficients are meant by added(virtual)mass and include added moments of inertia and cross coupling terms such as force coefficients due to linear and angular accelerations.Dynamic equation of an underwater manipulator which has n-joints is as follows:=M(q,q)+C(q,q)q+F(q)+G(q)+D(q,q)where q is the joint angular position,M is the inertia matrix,C denotes the Coriolis,centrifugal forces,G represents the gravity forces which include buoyancy effects,F is the friction terms,D is the hydraulic drag forces which caused by the relative velocity of manipulator to ocean current and waves,is the vector of applied joint torques which are actually control inputs,2.1 Dof(Degrees of Freedom)The number of independent movements that the manipulators can perform in a 3-D space is called the number of degrees of freedom.Manipulator arms can provide multiple degrees of freedom,as shown on the following figure1 of the advanced Kraft TeleRobotics Predator-7.Basically,there are two types of movement for manipulator which is translation and rotation.Translation represents linear motions along three perpendicular axes,specify the position of the body and rotation represents angular motions about the three axes,specify the orientation of the body.The determination of dof depends on the task of that manipulator.A common strategy in design is to put a 3-dof base to achieve arbitrary position,and add a 3-dof spherical wrist to achieve arbitrary orientation.Often the task at hand does not require a full 6-dof,e.g.when task objects exhibit symmetry,or when no obstacle in workspace,or simply when the task involves limited directions of movement.Obviously,it is optimum to design the manipulator with the minimum dof that will achieve the task.This reduces cost and simplifies the analysis.Most of the International Conference on Control,Instrumentation and Mechatronics Engineering(CIM07),Johor Bahru,Johor,Malaysia,May 28-29,2007726commercial underwater manipulators operate by mounting on the underwater vehicles.Some of them are just designed with a small number of dof because the vehicle itself has its own dof.However,JASON has a general purpose manipulator with six dof.Figure2 shows the manipulator arm of JASON.Figure 1:Kraft TeleRobotics Predator Figure 2 :Manipulator arm of JASON 2.2 Workspace extent The workspace of a manipulator is defined as the volume of space in which the manipulator is able to locate its end-effector.Thus,in this analysis the workspace is referring to the underwater surrounding.Sometimes the shape of the workspace needs to be considered.The manipulator workspace is characterized by the mechanical joint limits in addition to the configuration,link length and the number of degrees of freedom of the manipulator.The workspace gets specified by the existence or nonexistence of solutions to the inverse kinematics problem.The region that can be reached by the origin of the endeffector frame with at least one orientation is called the reachable workspace(RWS).If a point in workspace can be reached only in one ormanipulatability of the end-effector is very poor and it is not possible to do any practical work satisfactory with just one fixed orientation.It is,therefore,necessary to look for the points in workspace,which can be reached in more than one orientation.The space commercial underwater manipulators operate by mounting on the underwater vehicles.Some of them are just designed with a small number of dof because the vehicle itself has its own dof.However,JASON has a general purpose manipulator with six dof.shows the manipulator arm of JASON.Predator-7:Manipulator arm of JASON The workspace of a manipulator is defined as the volume of space in which the manipulator is able to effector.Thus,in this analysis the workspace is referring to the underwater surrounding.space needs to be considered.The manipulator workspace is characterized by the mechanical joint limits in addition and the number of degrees of freedom of the manipulator.The workspace nonexistence of solutions to the inverse kinematics problem.The region that can be reached by the origin of the end-effector frame with at least one orientation is called the(RWS).If a point in workspace can be reached only in one orientation,the effector is very poor and it is not possible to do any practical work satisfactory with just one fixed orientation.It is,therefore,necessary to look for the points in workspace,which n one orientation.The space where the end-effector can reach every point from all orientations is called dexterous workspaceno solution can be determined for a particular manipulator pose that configuration is said to be singular.These singularities represent the boundary and/or the internal singularities.Surface patches corresponding to these singularities represent the singular surfaces within the workspace.As it is impossible to move the tip of the manipulator along the singular surfaces,no matter which joint rates are selected,they are to be avoided during manipulation.Any point lying on a singular surface will have zero manipulability.2.3 Load carrying capacity The load required to be carried by the robot will govern the size of its motors,and theintegrity of its joints and links.For the same level of structural integrity,the payload capacity will decrease as the workspace volume increases.2.4 End effector maximum speed The faster a task can be achieved,is the robot compared to hard automation or human workers.Cycle time,the time taken to achieve a complete move,is a function endalso on the accelerations possible during the acceleration and deceleration phases.capability is also of importance.2.5 Repeatability and accuracy This is one of the critical properties of any robot.Constructing a robot with high accuracy and repeatability is expensive:stiffer links,tighter tolerance joints,position sensing,and modeling and etc.The aim should be for the minimum accuracy and repeatability required by the task.External sensing,particularly force sensing,is a means in many tasks to reduce the required level or accuracy.This has been and still is a current active research area.effector can reach every point from all dexterous workspace(DWS).If no solution can be determined for a particular manipulator pose that configuration is said to be singularities represent the boundary and/or the internal singularities.Surface patches corresponding to these singularities represent the singular surfaces within the workspace.As it is impossible to move the tip of the manipulator along the faces,no matter which joint rates are selected,they are to be avoided during manipulation.Any point lying on a singular surface will have zero The load required to be carried by the robot will ize of its motors,and the structural integrity of its joints and links.For the same level of structural integrity,the payload capacity will decrease as the workspace volume increases.2.4 End effector maximum speed The faster a task can be achieved,the more viable is the robot compared to hard automation or human workers.Cycle time,the time taken to achieve a complete move,is a function end-effector speed,but also on the accelerations possible during the ration and deceleration phases.So acceleration 2.5 Repeatability and accuracy This is one of the critical properties of any robot.Constructing a robot with high accuracy and repeatability is expensive:stiffer links,tighter tolerance joints,position sensing,and modeling and for the minimum accuracy and eatability required by the task.External sensing,particularly force sensing,is a means in many tasks to reduce the required level or accuracy.This has been and still is a current active research area.International Conference on Control,Instrumentation and Mechatronics Engineering(CIM07),Johor Bahru,Johor,Malaysia,May 28-29,20077273.Manipulator Kinematics and Dyanmics In this section we will reviewed the 2 important aspect of designing of robotic manipulator.Robotic manipulator is required to follow a trajectory to manipulate a certain object and to perform the task required in its given workspace.The first aspect is the kinematic analysis of the manipulator and the second parameter is the dynamics.3.1 Kinematic Kinematic model describes the spatial position of the joints and links and position and orientation of the end-effector 1.It is basically a way to establish a relationship between the joints variables and the link position and orientation.The forward kinematics involves the process of establishing the position and orientation of the end effector with based on the joint variables.Inverse kinematic on the other hands involves relates the joint variables when the end effector position and orientation has been ascertain.In this work we have used the Denavit-Hartenberg convention in naming the link and frame.This corresponds with the method which is also been applied to the torque computation which is been used by Peter Corke 2.Figure 3:Denavit-Hartenberg Convention 1 As we can see in this frame naming convention the frame i,for link i is located at the distal end of the link.The following are the definition for the link parameters.i)Link length,ai ii)Link twist,is the angle of between zi and zi-1 which is read from xi.iii)Link offset,di,is the distance from origin of frame i-1 to frame i.iv)Joint angle,is the angle between the xi-1 to xi from zi Another convention that is being used is the modified denavit-hartenberg convention which utilizes the framei to be the same as jointi3.The linear velocity of frame i,will be determine by the following equation?i,is the frame D,is the position matrix with respect to frame i The angular velocity of the link with respect to the base frame is described as follows?w,is the angular velocity 3.2 Dynamics Dynamic behavior of a robotic manipulator is defined as a time-varying movement of the manipulator.This time varying movement is controlled by the torque which is applied through the link joints.The internal torque generated is caused by the motion of the links itself while the external force which acts upon the links includes load and the gravitational forces.There are a number of dynamic modeling method which is applicable.The most common are the Langrange-Euler(LE)and Newton-Euler(NE).Tarn,Yang,Shoults 4,has used kanes method instead for their dynamic modeling of underwater manipulator.Kanes method is a combination of both EL and LE.In this method it actually eliminates the non-working link interaction forces.In this paper we have simulated the dynamics using the NE.The newton euler methods relys on the fundamental principle of newtons motion law and the dAlembert principle.The force that is action at the center of the mass of the link is given by?F,Force m,mass,?linear acceleration of the link The euler equation for rotational movement is defined and characterize by the following equation.The angular velocity,wi and the moment of the inertia tensor Ii relates to the total moment,Ni as follows?International Conference on Control,Instrumentation and Mechatronics Engineering(CIM07),Johor Bahru,Johor,Malaysia,May 28-29,2007728 In the recursive newton euler method,involves two part of computation.The first part is the forward iteration which involves the calculation of the velocity and acceleration starting from the base and moving towards the end-effector.The second part is the backward iteration whereby we use the velocity and acceleration that was computed initially and starting from the end-effector to calculate the force and moment and moving backwards towards the base frame.The following equation summarizes the backward iteration calculation?whereby iRi+1 is the rotational matrix of frame i+1 with respect to frame i,D is the position matrix.f and n is the force that is acting at the joints itself.is the torque which is required for the joints which depends either the joints are prismatic or revolute.4.Hydrodynamics In order to accurately model underwater manipulator,we are required to take into account additional effect that is caused by the motion of the incompressible fluids itself.These forces are a result from incompressible fluids which is determined by the Navier-Stokes equation5.In this paper we would consider 4 major hydrodynamics effect which are the added mass,added coriolis and centripetal,drag force and buoyancy.4.1 Added Mass The added mass is generated when a rigid body moves in a fluid.The fluid will also be accelerated by the movement of the body which requires an additional force.This effect is neglected in typical industrial robotic due to the low density of the air
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