• Journal of Computational Design and Engineering
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• v.3 no.2
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• pp.132-139
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• 2016

In this paper, a minimum time path planning strategy is proposed for multi points manufacturing problems in drilling/spot welding tasks. By optimizing the travelling schedule of the set points and the detailed transfer path between points, the minimum time manufacturing task is realized under fully utilizing the dynamic performance of robotic manipulator. According to the start-stop movement in drilling/spot welding task, the path planning problem can be converted into a traveling salesman problem (TSP) and a series of point to point minimum time transfer path planning problems. Cubic Hermite interpolation polynomial is used to parameterize the transfer path and then the path parameters are optimized to obtain minimum point to point transfer time. A new TSP with minimum time index is constructed by using point-point transfer time as the TSP parameter. The classical genetic algorithm (GA) is applied to obtain the optimal travelling schedule. Several minimum time drilling tasks of a 3-DOF robotic manipulator are used as examples to demonstrate the effectiveness of the proposed approach.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.37 no.9
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• pp.655-662
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• 1988

An adaptive control scheme has been recognized as an effective approach for a robot manipulator to track a deired trajectory in spite of the presence of nonlinearies and parameter uncertainties in robot dynamic models. In this paper, an adaptive control scheme for a robot manipulator is proposed to design the self-tuning controller which controls the extended linearized perturbaton model via the pole placement, and this control. The feasibility of the controller is demonstrated by the simulation about position control of a three-link manipulator with payload and parameter uncertainty.

• The Journal of Korean Institute of Communications and Information Sciences
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• v.21 no.1
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• pp.291-299
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• 1996

A new identification method using a higher order multilayer neural network is proposed for identifying a complex dynamic system such as a robotic manipulator. The input torque data for learning of the neural identifier are generated for producing effective output trajectories by a minimization process of a specific performance index function which indicates the difference between the reference points and the present joint positions and their velocities of the robotic manipulator. Computer simulation results show that the proposed identification method is very effective for identifying the systems with complex dynamics and large moment of inertia.

• 제어로봇시스템학회:학술대회논문집
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• 2003.10a
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• pp.2540-2545
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• 2003

We propose a new technique to the design and real-time implementation of an adaptive controller for robotic manipulator based on digital signal processors in this paper. The Texas Instruments DSPs(TMS320C80) chips are used in implementing real-time adaptive control algorithms to provide enhanced motion control performance for dual-arm robotic manipulators. In the proposed scheme, adaptation laws are derived from model reference adaptive control principle based on the improved direct Lyapunov method. The proposed adaptive controller consists of an adaptive feed-forward and feedback controller and time-varying auxiliary controller elements. The proposed control scheme is simple in structure, fast in computation, and suitable for real-time control. Moreover, this scheme does not require any accurate dynamic modeling, nor values of manipulator parameters and payload. Performance of the proposed adaptive controller is illustrated by simulation and experimental results for a dual arm robot consisting of two 4-d.o.f. robots at the joint space and cartesian space.

• 제어로봇시스템학회:학술대회논문집
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• 1993.10a
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• pp.552-558
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• 1993

In this paper, control of a planar two-link structurally flexible robotic manipulator executing unconstrained and constrained maneuvers is considered. The dynamic model, which is obtained by using the extended Hamilton's principle and the Galerkin criterion, includes the impact force generated during the transition from unconstrained to constrained segment of the robotic task. A method is presented to obtain the linearized equations of motion in Cartesian space for use in designing the control system. The linear quadratic Gaussian with loop transfer recovery (LQG/LTR) design methodology is exploited to design a robust feedback control system that can handle modeling errors and sensor noise, and operate on Cartesian space trajectory errors. The LQG/LTR compensator together with a feedforward loop is used to control the flexible manipulator. Simulated results are presented for a numerical example.

• 제어로봇시스템학회:학술대회논문집
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• 1988.10b
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• pp.981-986
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• 1988

A controller synthesis procedure for precise tracking of reference inputs in the sense of spheres is applied to a 3 d.o.f. robotic manipulator. This methodology applies to a class of nonlinear systems with input uncertainty and parameter uncertainty. The 3 d.o.f. manipulator to be controlled is subjected to varying payloads and is required to follow specified joint trajectories to within prespecified tolerances. The design procedure above lends itself naturally to this type of control problem. The appeal of such a design procedure lies on a special decomposition which exploits linear control theory on the one hand and facilitates a separate treatment of the effects of nonlinearities and the uncertainties on the other.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1992.04a
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• pp.369-373
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• 1992

Force control of a planar two-link structurally flexible robotic manipulator is considered in this study. The dynamic model is obtained by using the extended Hamilton's principle and the Galerkin criterion. A method is pressented toobtain the linearized equations of motion in Cartesian space for use in designing the control system. The approachto solving the control problem is to use feedforward and feedback control torques. The feedforward torques maneuver the flexible manipulatro along a nominal trajectory and the feedback torques minimize any deviations from the nominal trajectory. The linear quadratic Gaussian/loop transfer recovery (LQG/LTR) design methodology is explotied to design a robust feedback control system that can handle modeling errors and sensor noise, and operates on Cartesian space trajectory errors. The Lqg/LTR compenstaor together with a feedforward ollp is used to control the flexible manipulator. Simulated results are presented for a numerical example.

• 제어로봇시스템학회:학술대회논문집
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• 1987.10b
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• pp.41-46
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• 1987

A new control scheme is developed to achieve fast and accurate decoupled tracking for an n-Joint robotic manipulator In the Presence of disturbances and unknown Parameter variations. The control system is designed so that a new type of state trajectories called sliding mode may exist in a phase plane. In order to remove the reaching Phase and high frequency chattering phenomenon which ate the common shortcomings of variable structure control(VSC) scheme, this paper presents the new switching line which is composed of three segments and the continuous control law which is derived from the existence condition of a sliding mode. The Proposed methods in this Paper are applied to a 3-Joint robotic manipulator as a numerical example-The digital simulation results which are compared with those of typical VSC scheme show the validity of accurate tracking capability and robust Performance of the system.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.243-246
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• 1996

Modular robot manipulator is a robotic system assembled from discrete joints and links into one of many possible manipulator configurations. This paper describes the design method of newly developed modular robot manipulator and the methodology of a task based reconfiguration of it. New locking mechanism is proposed and it provides quick coupling and decoupling. A parallel connection method is devised and it makes modular robot manipulator working well and the number of components on each module reduced. To automatically determine a sufficient or optimal arrangement of the modules for a given task, we also devise an algorithm that automatically generates forward and inverse manipulator kinematics, and we propose an algorithm which maps task specifications to the optimized manipulator configurations. Efficient genetic algorithms are generated and used to search for a optimal manipulator from task specifications. A few of design examples are shown.

• The Journal of Korea Robotics Society
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• v.6 no.4
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• pp.344-352
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• 2011

A mobile manipulator is a system with a robotic manipulator mounted on top of a mobile base. It has both indoor and outdoor applications for transporting or transferring materials. When a user gives commands, they are usually at high levels such as "move the object to the table," or "tidy the room." By intelligently decomposing these complex commands into several subtasks, the mobile manipulator can perform the tasks with a greater efficiency. One of the crucial subtasks for these commands is the pick-and-place task. For the mobile manipulator, selection of a good base position and orientation is essential to accomplishing this task. This paper presents an algorithm that determines one of the position and orientation of a mobile manipulator in order to complete the pick-and-place task without human intervention. Its effectiveness are shown for a mobile manipulator with 9 degrees-of-freedom in simulation.