Waveform control method was commonly adopted to reduce the spatter of CO2 arc welding and improve the weld formation. It certainly would reduce the self-regulation ability of arc due to the adoption of segmented const...Waveform control method was commonly adopted to reduce the spatter of CO2 arc welding and improve the weld formation. It certainly would reduce the self-regulation ability of arc due to the adoption of segmented constant current control which especially led to arc＂ blowout with the abrupt change oat＂ arc＂ length or downward welding. Therefore alterative wire-feed system based on arc voltage negative feedback was put forward to improve the .stability of arc＂ length in this paper. Double closed-loop and double fuzzy P1 regulation were adopted in this system. Fuzzy control of induced voltage was adopted in the inner-loop which improved the stability and fast response of wire-feed system. Fuzz）＂ control of arc＂ voltage negative feedback was used in the outer-loop whose output .served as the input of negative feedback regulation of inner-loop induced voltage. This method could remain arc＂ length and weld penetration unchan, ged on the basils of reducing spatter and improving formation and it was proved by downward welding tests.展开更多
The subject matter of this paper is the representation of the solution of the linear differential equation Y = AY - YB, Y(0) = Yo, in the form y(t) = eΩ(t)Y0 and the representation of the function n as a generalizati...The subject matter of this paper is the representation of the solution of the linear differential equation Y = AY - YB, Y(0) = Yo, in the form y(t) = eΩ(t)Y0 and the representation of the function n as a generalization of the classical Magnus expansion. An immediate application is a new recursive algorithm for the deriVation of the Baker- Campbell-Hausdorff formula and its symmetric generalization.展开更多
文摘Waveform control method was commonly adopted to reduce the spatter of CO2 arc welding and improve the weld formation. It certainly would reduce the self-regulation ability of arc due to the adoption of segmented constant current control which especially led to arc＂ blowout with the abrupt change oat＂ arc＂ length or downward welding. Therefore alterative wire-feed system based on arc voltage negative feedback was put forward to improve the .stability of arc＂ length in this paper. Double closed-loop and double fuzzy P1 regulation were adopted in this system. Fuzzy control of induced voltage was adopted in the inner-loop which improved the stability and fast response of wire-feed system. Fuzz）＂ control of arc＂ voltage negative feedback was used in the outer-loop whose output .served as the input of negative feedback regulation of inner-loop induced voltage. This method could remain arc＂ length and weld penetration unchan, ged on the basils of reducing spatter and improving formation and it was proved by downward welding tests.
文摘The subject matter of this paper is the representation of the solution of the linear differential equation Y = AY - YB, Y(0) = Yo, in the form y(t) = eΩ(t)Y0 and the representation of the function n as a generalization of the classical Magnus expansion. An immediate application is a new recursive algorithm for the deriVation of the Baker- Campbell-Hausdorff formula and its symmetric generalization.
