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The goal of this thesis is to design and fabricate a four degrees freedom underwater manipulator for small to midsize remotely operated vehicles. DC servo motors were used to actuate the manipulator joints such that the size and the necessary auxiliary components can be reduced. In terms of hardware design process, the selection of servo motors and their arrangement is the key to the overall performance of the manipulator. The design of any joint, including its location and fixture to the frame, is coupled with that of the neighboring joints such that the design itself is an iterative process. Proper choice of the torque and power of an actuator not only reduces its size but also ease the loading the joints proximal to the base. In this project, the water resistance between stationary and rotary interfaces are achieved by O-ring and mechanical seals respectively. A gripper, synthesized and analyzed with kinematic chain theory, was implemented with a single degree freedom six-bar linkage as the end-effector of the manipulator. Because the robot is designated to operate in underwater environment, the dynamics of the system is relative slow and insignificant. Therefore, the only the linearized kinematics of the manipulator is concerned, and the motion controller is implemented with Jacobian in Visual Basic. Under 50 Hz servo rate, gravity compensation is added for operation in the air, and in the water as well. For the operating speed limited to 20 mm/sec, the overall positioning error is confined to be less than 1 mm for all time.

To expand the ability of collecting underwater targets of "Remotely Operated Vehicle II", developed by National Sun Yat-sen University and National Cheng Kung University, this research will develop an underwater manipulator system which can be integrated with ROV II to have enough degrees of freedom to carry out sampling. The goal will focus on mechanism design and to distinguish the assemble restrictions from other mechanism modules. To avoid use of hydraulic pressure apparatus, the manipulator system will use electric motors as the source of drive, which feeds on ROV II's electricity. In mechanical design, water tightness of underwater manipulator system is first considered to avoid damage of internal electric components. Therefore, in this research, suitable waterproof components will be selected separately for static and dynamic machine parts, and dimension and tolerance of assembly of waterproof components will be analyzed. Then, according to decided design conditions, the number of degrees of freedom of the manipulator and range of length of the arm will be decided. The final design model will be constructed, and selection of motors will be finished by 3D Computer Aided Solid Drawing Software. To have a manipulator system which can deal with different targets, the gripper design needs to consider to easily replacement. In the aspect of systematic control, commercial motor control card and motor driver chip are used to carry out the structure of the entire control system, and develop control interface by C language to easily control each joint of the manipulator system.

For amanipulator to carry outmultiple sampling tasks in a single ROV dive, the samples collected need to be stored temporarily in a secure space to free the gripper for the next sampling. The goal of this research is to design and fabricate a sample holding device to improve the efficient of the ROV which was developed jointly by National Sun Yat-sen University and National Cheng-Kung University. The sample bay mounted on a linear track, moves forward to be in the workspace of the manipulator for the storage service. Upon completion of the sample storage tasks, it retrieves back into the ROV frame to prevent itself from being hit or damaged when the ROV is in motion. The development includes the design for a linear track, an underwater motor and its controller, and sample holder. The design of the sample holder was implemented by decision weighting matrix to choose the most appropriate prototype. The efficacy of the system was verified by several joint tests with the manipulator.

Graduate

The purpose of this thesis is to present a comprehensive and practical approach for the time-optimal motion planning and control of a general purpose industrial manipulator. In particular, the case of point-to-point path unconstrained motions is considered, with special emphasis towards strategies suitable for efficient on-line implementations. From a dynamic model description of the plant, and using an advanced graphical robotics simulation environment, the control algorithms are formulated. Experimental work is then conducted to verify the proposed algorithms, by interfacing the industrial manipulator to the master controller, implemented on a personal computer. The full rigid-body non-linear dynamics of the open-chain manipulator have been accommodated into the modelling, analysis and design of the control algorithms. For path unconstrained motions, this leads to a model-based regulating strategy between set points, which combines conventional trajectory planning and subsequent control tracking stages into one. Theoretical insights into these two robot motion disciplines are presented, and some are experimentally demonstrated on a CRS A251 industrial arm. A critical evaluation of current approaches which yield optimal trajectory planning and control of robot manipulators is undertaken, leading to the design of a control solution which is shown to be a combination of Pontryagin's Maximum Principle and state-space methods of design. However, in a real world setting, consideration of the relationship between optimal control and on-line viability highlights the need to approximate manipulator dynamics by a piecewise linear and decoupled function, hence rendering a near-time-optimal solution in feedback form. The on-line implementation of the proposed controller is presented together with a comparison between simulation and experimental results. Furthermore, these are compared with measurements from the industrial controller. It is shown that the model-based near-optimal-time feedback control algorithms allow faster manipulator motions, with an average speed-up of 14%, clearly outperforming current industrial controller practices in terms of increased productivity. This result was obtained by setting an acceptable absolute error limit on the target location of the joint (position and velocity) to within [2.0E-02 rad, 8.7E-03 rad/s], when the joint was regarded at rest.

Zugl.: Rostock, University, Diss.

This thesis is a feasibility study for a manipulator for an automated assembly of inductors for the automotive industry. Firstly there is an analysis of the current production status. Secondly there is a proposed concept for mechanical, electrical and pneumatic parts of such a machine. Next is the description of the production and completion of the manipulator. And the final part deals with the implementation of this device.

A kinematically redundant four degrees of freedommanipulator arm, a knuckle boom, is studied. Three joints arerevolute and one linear. Since only three degrees of freedomare needed for positioning, we have one redundant degree offreedom. Three different kinematic control strategies arestudied. One is based on the maximization of velocity (localoptimisation). This strategy is non-repeatable and cansometimes lead to kinematically unfavourable positions. In thesecond strategy, which is based on the maximization of staticlifting capacity (local optimisation), one of the degrees offreedom (the linear joint) is made a function of the toolcentre point position. The third strategy, which is based ondynamic programming (global optimization), calculates theshortest time that is possible for the tool centre point to gofrom one point to another point in the working area. The threestrategies are compared in a simulation study. The simulationsshow the necessary speed requirements for all joints whenperforming straight paths in the manipulator work area. Thesimulations also show the difference in time consumptionsbetween the three control algorithms and also what happens whenthe joints reach their maximum velocity limits. KeywordsManipulator, Kinematic Control, RedundantLanguage

A novel algorithm for the simplified tele-operation of mobile-manipulator systems is presented. The algorithm allows for unified, intuitive, and coordinated control of mobile manipulators, systems comprised of a robotic arm mounted on a mobile base. Unlike other approaches, the mobile-manipulator system is modeled and controlled as two separate entities rather than as a whole. The algorithm consists of thee states. In the rst state a 6-DOF (degree-of-freedom) joystick is used to freely control the manipulator's position and orientation. The second state occurs when the manipulator approaches a singular configuration, a con guration where the arm instantaneously loses a DOF of motion capability. This state causes the mobile base to proceed in such a way as to keep the end-effector moving in its last direction of motion. This is done through the use of a constrained optimization routine. The third state is triggered by the user: once the end-effector is in the desired position, the mobile base and manipulator both move with respect to one another keeping the end-effector stationary and placing the manipulator into an ideal configuration. The proposed algorithm avoids the problems of algorithmic singularities and simplifies the control approach. The algorithm has been implemented on the Jasper Mobile-Manipulator System. Test results show that the developed algorithm is effective at moving the system in an intuitive manner.