This study was aimed at optimizing the structural design of the robot in regards to two main aspects: link shape and link dimension. This paper presents a method to find an optimal function of link cross-sectional rad...
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This study was aimed at optimizing the structural design of the robot in regards to two main aspects: link shape and link dimension. This paper presents a method to find an optimal function of link cross-sectional radius that provides uniform bending stress along the length of a hollow shaft. This method was successfully applied to some other cases such as a hollow rectangle. We also present a method to determine the optimal link lengths of a manipulator with six revolute joints based on the method introduced in [1]. These optimized dimensions minimize average required torque at each joint.
This paper describes the development and verification of a dynamic model for a Cartesian manipulator. Experiments and simulations are performed in order to determine the parameters of the established model. Optical sh...
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This paper describes the development and verification of a dynamic model for a Cartesian manipulator. Experiments and simulations are performed in order to determine the parameters of the established model. Optical shaft encoder feedback was proven to be unsatisfactory predominantly due to elasticity of the couplings and ball-nut backlash. As a result, a laser interferometry-based measurement system was used for position data acquisition. Experimental results highlight the occurrence of limit-cycles due to inherent friction by the rails, ball-nuts and bearings. The derived model parameters were determined both by theoretical calculations and experimental response observation.
In this paper, a new method for adjusting the height of a cylindrical pair in a static environment is presented. Generic force formulations are established. A technique to uniquely identify the type of contact based o...
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In this paper, a new method for adjusting the height of a cylindrical pair in a static environment is presented. Generic force formulations are established. A technique to uniquely identify the type of contact based on the force and torque data provided by a wrist mounted F/T sensor is developed. For small clearances between the links, the assumption of using zero misalignment in the formulations is justified by means of simulations. Friction, which is a key parameter for contact type identification is experimentally determined. Preliminary experimental results indicate that the presented technique is effective in determining the type of contact for the height adjustment operation.
This paper presents a methodology to create 3D visualization of discrete event simulation. This methodology connects discrete event simulation directly to 3D animation with its novel methods of analyzing and convertin...
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This paper presents a methodology to create 3D visualization of discrete event simulation. This methodology connects discrete event simulation directly to 3D animation with its novel methods of analyzing and converting discrete simulation results into animation events to trigger 3D animation. Discrete simulation results are analyzed and displayed in a graph structure that reveals all possible sequences of simulation events. In addition, a 3D animation framework is constructed for the visualization of discrete simulation results. This framework supports the reuse of both the existing 3D animation objects and behavior components, and allows the rapid development of new 3D animation objects by users with no special knowledge in computer graphics. This methodology has been implemented with the software component technology. Results in an electronics assembly factory are also provided in the paper to demonstrate the feasibility of this approach.
This paper presents the development of a full order sliding mode controller for tracking problem of direct drive robot manipulators. By treating the arm as an uncertain system represented by its nominal and bounded pa...
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This paper presents the development of a full order sliding mode controller for tracking problem of direct drive robot manipulators. By treating the arm as an uncertain system represented by its nominal and bounded parametric uncertainties, a new robust full order sliding mode tracking controller is derived such that the actual trajectory tracks the desired trajectory as closely as possible despite the nonlinearities and input couplings present in the system. A proportional-integral sliding surface is chosen to ensure the stability of overall dynamics during the entire period i.e. the reaching phase and the sliding phase. Application to a three DOF direct drive robot manipulator is considered.
This paper presents a methodology for optimum dynamic balancing of planar parallel manipulators typified with a variable speed 2 DOF parallel manipulator articulated with revolute joints. The dynamic balancing is form...
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This paper presents a methodology for optimum dynamic balancing of planar parallel manipulators typified with a variable speed 2 DOF parallel manipulator articulated with revolute joints. The dynamic balancing is formulated as an optimisation problem such that a sum-squared values of bearing forces, driving torques, shaking moment, and the deviation of the angular momentum from its mean value are minimized throughout an operation range of the manipulator, provided that a set of balancing constraints consisting of the shaking force balancing conditions, the sizes of some inertial and geometric parameters are satisfied. Sets of optimisation results corresponding to various combinations of the elements of the objective function are evaluated in order to quantify their influence on the resulting bearing forces, the driving torques, shaking moment and force. The results prove that the proposed optimisation approach can be used to minimize any desired combination of the forces, moments, and torques involved in any parallel mechanism by choosing a suitable set of weighting factors. The method is systematic, versatile and easy to implement for the optimum balancing of the parallel manipulator and more general parallel manipulators.
Since teleoperation systems are mostly executed in the extreme environment, there are constraints in designing the mechanism and choosing sensors. This paper presents a novel quantitative comparison method of teleoper...
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ISBN:
(纸本)0780384636
Since teleoperation systems are mostly executed in the extreme environment, there are constraints in designing the mechanism and choosing sensors. This paper presents a novel quantitative comparison method of teleoperators based on H∞, framework. The upper H∞ norm bound of the system including H∞ sub optimal controller is used as the performance index. As a case study, the method is applied to a real teleoperation system to study the effects of sensory configuration and back-drivability of the mechanism on the performance of the system in tasks which involve different environment impedances. It can be important criteria to design a teleoperator from the control point of view.
In this paper we describe the design and implementation of a nonlinear adaptive disturbance rejection approach for single-input-single-output linear-time-invariant uncertain systems subject to sinusoidal disturbances ...
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In this paper we describe the design and implementation of a nonlinear adaptive disturbance rejection approach for single-input-single-output linear-time-invariant uncertain systems subject to sinusoidal disturbances with unknown amplitude and frequency. This is an extension of our earlier study to a more complicated plant, a two-degrees-of-freedom (2DOF) system representing a vibration absorber setting. The controller design is based on a single Lyapunov function incorporating both the error states and the update laws and, hence, global stability and improved transient performance are readily achieved. Utilizing only the system output, a virtual control input is used in place of non-measurable and unknown signals. The performance of the adaptation algorithm is demonstrated through real-time simulations, both for regulation and tracking, on a 2DOF system representing an active vibration absorber setup. It is shown that when the primary system is subjected to an unknown sinusoidal disturbance, the proposed controller in the absorber subsection completely suppresses the primary system vibration in the presence of unknown disturbance.
＜正＞In this paper a new version of the Cassino parallel manipulator （CaPaMan 2） is presented. A model describing the multibody system through mixed coordinates has been created, and a simulation program has been d...
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＜正＞In this paper a new version of the Cassino parallel manipulator （CaPaMan 2） is presented. A model describing the multibody system through mixed coordinates has been created, and a simulation program has been developed to perform both kinematic and dynamic analysis of the manipulator. This program uses an entirely symbolic formulation of the equations of motion for the mechanism.
Drive-by-wire is becoming a new technology in automobile replacing the current mechanically linked systems with electronic ones. Lately, it has attracted considerable attention, because of considerable advantages incl...
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Drive-by-wire is becoming a new technology in automobile replacing the current mechanically linked systems with electronic ones. Lately, it has attracted considerable attention, because of considerable advantages including safety, cost reduction, flexible interior design, reducing the weight and etc. With the ‘by-wire’ system, drivers could use different types of control devices in shape and function for the existing steering wheel and pedals, or even drive by one control device integrating the brake pedal, accelerator pedal and other functions. In this paper, a new drive-by-wire system is built by using the Electric Power Steering (EPS), Accelerator Pedal Module (APM) and a simple actuating mechanism for brake pedal. Especially, we concentrate on steer-by-wire system. To improve the accuracy and safety in steering, a new type of integrated reactive joystick and control algorithm is developed. The new joystick has larger displacement than general commercial joysticks and can generate the reactive force which promotes safe driving by preventing too fast steering. The new control scheme is one of the bilateral controls that stands on the base of the teleoperation control. Therefore, drivers could get more information about the status of car. The experiment is performed by a field test using a real car and shows the performance of this steer-by-wire system with control algorithm.
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