An intelligent waveform control system with micro-controller is developed for robotic high-speed CO2 arc welding. In order to resolve the problems of bad weld formation and heavy spatter in high-speed CO2 arc welding,...
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ISBN:
(纸本)9783540733737
An intelligent waveform control system with micro-controller is developed for robotic high-speed CO2 arc welding. In order to resolve the problems of bad weld formation and heavy spatter in high-speed CO2 arc welding, A new method of welding current waveform control is investigated, which controls the short-circuit current and its rising rate in short-circuit period, and adopts the two-step constant current control to adjust the arc energy in arc period. The control principle of the method is discussed, the system structure and the control software are introduced, and the optimized waveform control parameters are provided by experiments. The results show that this system can precisely control the arc energy by the two-step constant current method and improves the performance of high-speed welding process obviously.
A real-time automatic inspection algorithm of weld defects in X-ray images was developed in this paper. Using optimized image smoothing and image information fusion based heuristic best-first search techniques, the al...
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ISBN:
(纸本)9783540733737
A real-time automatic inspection algorithm of weld defects in X-ray images was developed in this paper. Using optimized image smoothing and image information fusion based heuristic best-first search techniques, the algorithm can detect different kinds of defects in weld, such as slag inclusion, blow hole, incomplete penetration, lack of fusion and undercut etc. Experiments show that the algorithm is efficient, reliable and can be used for industrial purpose.
In vision-based robotic arc welding had some degree of autonomy functions, sensors must be used to detect the position and orientation of a weld seam and determine its path in order to carry out the autonomy of weldin...
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ISBN:
(纸本)9783540733737
In vision-based robotic arc welding had some degree of autonomy functions, sensors must be used to detect the position and orientation of a weld seam and determine its path in order to carry out the autonomy of welding process. This paper represented a method to recognize whole seam in complex robotic welding environment. According to the parameter we defined to judge the degree of image noise, then different size of filter windows were selected to preprocess the image. Algorithm to eliminate effect of complex changing background is proposed. Parameters are defined to judge if it is necessary to use this algorithm. The threshold and edge detect algorithms that adapt to the recognition for robotic welding environment is also addressed in this paper. The experiments give the recognition results of two different shapes and material of seams. The results showed that the recognized method was robust to the recognition of macroscopic seam for complex robotic welding environment.
This paper presents an energy optimization method of the safety door's motion control. Considering the multiple factors that affect the safety door's energy consumption, we establish an objective function and ...
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ISBN:
(纸本)9783540733737
This paper presents an energy optimization method of the safety door's motion control. Considering the multiple factors that affect the safety door's energy consumption, we establish an objective function and a constraint equation, and propose an energy optimization method based on Sequential Quadratic Programming (SQP) algorithm. The controllable curve of the instantaneous linear velocity for the safety door based on the optimization design can be finally obtained. This method has been proved to be effective by experiments.
Enlargement of electrode face diameter in resistance spot welding was the main factor that led to undersize nugget diameter. A mathematics model was established to estimate electrode face diameter by applying the char...
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ISBN:
(纸本)9783540733737
Enlargement of electrode face diameter in resistance spot welding was the main factor that led to undersize nugget diameter. A mathematics model was established to estimate electrode face diameter by applying the characteristic that servo gun can detect axial wear online but not equip additional measurement apparatuses. Firstly the precision of servo gun was compensated to assure it can meet the requirement of axial wear measurement online. Then the model was established to estimate electrode face diameter online by a minimum amount of experiment data to determine the numerical constant in the model. To verify the model, electrode life tests for welding different galvanized steels were carried out. It was shown that estimation results of the model agreed well with the experiment results and spot welding the steels with higher electrode wear rate would result in a shorter electrode life.
An energy balance equation with respect to a control contact system provides port outputs which are conjugated to inputs. These conjugate variables are used to define the composition of port contact systems in the fra...
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ISBN:
(纸本)9783540738893
An energy balance equation with respect to a control contact system provides port outputs which are conjugated to inputs. These conjugate variables are used to define the composition of port contact systems in the framework of contact geometry. We then propose a power-conserving interconnection structure, which generalizes the interconnection by Dirac structures in the Hamiltonian formalism. Furthermore, the composed system is again a port contact system, as illustrated on the example of a gas-piston system undergoing some irreversible transformation.
A particular family of Hamiltonian functions is considered. Such functions are quadratic in the moment variables and arise in spaceflight mechanics when the averaged system of energy minimizing trajectories of the Kep...
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ISBN:
(纸本)9783540738893
A particular family of Hamiltonian functions is considered. Such functions are quadratic in the moment variables and arise in spaceflight mechanics when the averaged system of energy minimizing trajectories of the Kepler equation is computed. An important issue of perturbation theory and averaging is to provide integrable approximations of nonlinear systems. It turns out that such integrability properties hold here.
Total Energy Shaping is a controller design methodology that achieves (asymptotic) stabilization of mechanical systems endowing the closed-loop system with a Lagrangian or Hamiltonian structure with a desired energy f...
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ISBN:
(纸本)9783540738893
Total Energy Shaping is a controller design methodology that achieves (asymptotic) stabilization of mechanical systems endowing the closed-loop system with a Lagrangian or Hamiltonian structure with a desired energy function-that qualifies as Lyapunov function for the desired equilibrium. The success of the method relies on the possibility of solving two PDEs which identify the kinetic and potential energy functions that can be assigned to the closed-loop. Particularly troublesome is the PDE associated to the kinetic energy which is nonlinear and non-hornogeneous and the solution, that A defines the desired inertia matrix, must be positive definite. In this paper we prove that we can eliminate or simplify the forcing term in this PDE modifying the target dynamics and introducing a change of coordinates in the original system. Furthermore, it is shown that, in the particular case of transformation to the Lagrangian coordinates, the possibility of simplifying the PDEs is determined by the interaction between the Coriolis and centrifugal forces and the actuation structure. The example of a pendulum on a cart is used to illustrate the results. Copyright (C) 2006 IFAC.
As a key part of the photo-etching facility, the wafer prealigner uses mechanical or optical aligning method to save the time and guarantee the quality of manufacturing. In this paper, a new wafer prealigner is propos...
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ISBN:
(纸本)9783540733737
As a key part of the photo-etching facility, the wafer prealigner uses mechanical or optical aligning method to save the time and guarantee the quality of manufacturing. In this paper, a new wafer prealigner is proposed based on the mass center calculation method. The mass center is measured by a reflection-style laser sensor from the wafer's radial direction, and the position is measured by the notch angle detection using the penetration-style laser senor. A dynamic error compensation method is applied to eliminate the radial runout and wobble of the rotary stage, which have effects on measuring the wafer's mass center. The accuracy is improved through two steps: firstly, a coarse alignment is made by adjusting the mass center;secondly, a precise alignment is processed by aligning the wafer's notch. Experiments show that the accuracy of the wafer prealigner satisfied the system requirement.
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