Portal frame

About: Portal frame is a research topic. Over the lifetime, 1778 publications have been published within this topic receiving 7210 citations.

Numerical Simulations and Control of Offshore Energy Harvesting Using Piezoelectric Materials in a Portal Frame Structure

Abstract: Buoy systems are an alternative for micropowering small devices in remote locations. Portal frames are very useful to harvest the energy of the waves into usable energy. Thus, using the current models for a portal frame in the literature and the spectrum of available energy in sea waves, a nonlinear mathematical model accounting for the coupling of a nonlinear piezoelectric material is considered. The neighbour of selected variables is analyzed and then optimized by a process utilizing the particle swarm optimization (PSO) algorithm. Furthermore, an optimal control using the linear-quadratic regulator (LQR) controller is applied to control the load resistance of the piezoelectric circuit. The optimization process and the LQR show to be effective. The results show a general gain due to optimization and a relatively small gain using the controller.

Low-and-medium-frequency surface shape rapid detecting device and method for large-caliber optical elements

Abstract: The invention discloses a low-and-medium-frequency surface shape rapid detecting device and method for large-caliber optical elements The device comprises a numerical control computer case, a main control computer, a measuring portal frame, a dynamic interferometer, an interferometer fine adjusting mechanism, a working platform and air floatation guide rails The dynamic interferometer is mounted on the interferometer fine adjusting mechanism which is mounted on a beam of the measuring portal frame, and the measuring portal frame is disposed on the air floatation guide rails The measuring portal frame and the interferometer fine adjusting mechanism are connected with the numerical control computer case through cables The main control computer is connected with the numerical control computer case and the dynamic interferometer through signal lines Measuring main control software, dynamic interferometer measuring software and global wave surface fitting evaluation software are mounted on the main control computer By means of the device, sub-aperture data global wave surface fitting can be performed to obtain low-and-medium-frequency surface shapes of large-aperture surfaces to be tested, and accordingly, the sensitivity of interference measuring towards the environment is reduced, the requirement for measuring system geometric accuracy is reduced, the equipment integration level is high, the detection efficiency is high, and the measuring can be extended to be performed in the workshop environment

Light tilting-type rapid elevating forklift truck

Abstract: The invention relates to the field of elevating forklift truck devices, and discloses a light tilting-type rapid elevating forklift truck device made of a metal material. The device is provided with a high door-shaped portal frame and a low door-shaped portal frame, wherein the low portal frame is fixedly mounted on legs; the high portal frame and the legs are flexibly mounted together through support shafts at the lower end, and can tilt to facilitate the loading and unloading operation of objects. According to the device, hand wheels are pulled by double hands to drive a reel to wind and unwind a steel wire rope, so that the objects are supported and elevated by a pallet fork; the steel wire rope penetrates through a pulley block consisting of a fixed pulley suspended on the high portal frame and a movable pulley on a goods shelf frame, so that a labor-saving effect is achieved; the radiuses of the hand wheels are larger than or equal to the radius of the reel, so that the labor-saving effect is also achieved; by virtue of rollers at the four corners of the goods shelf frame, the goods shelf frame can be balanced and stably move up and down in the planes of the portal frames.

Solar backplane lamination equipment

Abstract: The utility model discloses a solar backplane lamination equipment, lamination equipment is including being arranged in the frame board in the press and fit process bearing, frame board top is provided with the portal frame, be provided with the pressfitting driver part on the portal frame, pressfitting driver part and pressfitting working head are connected and are driven the pressfitting working head and reciprocate, the frame board with be provided with the support between the pressfitting working head, be provided with on the support and place the regular positioning mechanism in position to solar backplane, be provided with ejecting driver part on the frame board, it places the part to be provided with the work piece that is used for placing solar backplane between frame board and the pressfitting working head, the work piece is placed the part and is driven by ejecting driver part The utility model has the characteristics of simple structure, convenient to use, production efficiency promotes in the especially adapted industry more also than higher simultaneously, especially is fit for the production and processing of little medium -sized enterprise