8results about How to "Small fluctuation range" patented technology

The invention relates to the technical field of aluminum alloy preparation, in particular to a 7075 aluminum alloy sheet and a preparation method thereof. The preparation method comprises the following steps: A) melting raw materials with specific components, and preserving heat at 720-760 DEG C; (B) carrying out furnace bottom degassing refining on the obtained melt, and then filtering; c) carrying out grain refinement on the obtained melt by adopting a refiner; d) casting the obtained melt under specific casting parameters to obtain a cast ingot; the method comprises the following steps of (1) carrying out primary soaking treatment on a cast ingot, (2) carrying out secondary soaking treatment on the cast ingot, (3) carrying out secondary soaking treatment on the cast ingot, and (4) carrying out rolling deformation on the treated cast ingot to obtain the 7075 aluminum alloy sheet. The cast ingot prepared through the method is fine in grain and compound and more dispersed and uniform in tissue distribution, and the finally obtained 7075 aluminum alloy sheet is stable in mechanical property and small in fluctuation range.

The embodiment of the invention provides a control method of a voltage converter and an energy storage system. The method comprises the following steps: a controller obtains accumulated required power of any control period; the controller judges whether the accumulated required power is greater than or equal to a set sending power threshold value; if the controller judges that the accumulated required power is greater than or equal to a sending power threshold value, the controller sets the output power as the accumulated required power; if the controller judges that the accumulated required power is smaller than the sending power threshold value, the controller sets the output power as a set value, and the set value is smaller than the sending power threshold value; the controller controls whether the voltage converter works or not according to the output power. According to the embodiment of the invention, the stability of power supply is improved, and the electronic equipment connected to the energy storage inverter is protected; generation of electromagnetic interference is reduced, and electromagnetic compatibility of the system is improved.

The invention discloses a smelting method of a low-sulfur copper-containing corrosion-resistant alloy, and aims to solve the technical difficulties that the yield of alloy elements is unstable and components are easy to segregate in the smelting process. The core of the technical scheme provided by the invention is that a'large-tonnage vacuum induction furnace + vacuum consumable electrode furnace 'double-vacuum combined smelting system is innovatively constructed by relying on the first 30-ton ALD imported vacuum induction furnace in China; and engineering mass production of the products is successfully realized through double precise regulation and control of alloy components and microstructures. The method has the beneficial effects that large-scale and engineering mass production of the corrosion-resistant alloy is successfully realized; chemical components are precisely regulated and controlled, so that the element yield stability is greatly improved; by means of refined management and control of a double-vacuum smelting system, the fluctuation range of alloy components is remarkably narrowed, high-quality steel ingots with uniform and consistent chemical components are finally produced by optimizing the process, follow-up product flaw detection standard reaching and performance stability are effectively supported, and macrostructures of finally forged bars are detected to meet relevant standards.

The application discloses a bridge operation modal analysis method based on structural dynamics and Gaussian process fusion, and can be used for bridge structure health monitoring. Acceleration sensors are arranged at key positions of the bridge to collect vibration responses in an operation state; mode force power spectral densities of each mode are extracted through frequency domain analysis as external excitation strength indexes. The indexes are taken as Gaussian process inputs and hidden variables are introduced to quantize influences of excitation changes on natural frequencies, damping ratios and vibration modes; an expectation-maximization algorithm is used to iteratively identify structural dynamics parameters and Gaussian process hyperparameters. Finally, the bridge modal parameters after excitation disturbances such as wind and vehicle flow are removed and the hyperparameters representing working conditions are obtained, and long-term tracking, evaluation and prediction of the bridge structure health are realized.

The application provides a mobile robot self-learning robust control method based on a hybrid Kalman filter and belongs to the technical field of robots.The technical scheme comprises the following steps: step 1, a dynamic model of an uncertainty factor;step 2, real-time estimation of state parameters and model parameters of the mobile robot to optimize the original dynamic model;step 3, introduction of an adaptive forgetting factor recursive least square method to dynamically adjust filter parameters;step 4, design of a non-singular fast terminal sliding mode controller based on a saturation function as a system main controller;step 5, establishment of an error correction RBF neural network and introduction of an adaptive error learning strategy;step 6, completion of stability analysis and proof of the control system by means of Lyapunov stability theory and simulation experiment of the optimized model.The application effectively suppresses the chattering of the sliding mode control and significantly improves the control precision and robust performance of the four-wheel robot.

The invention relates to the technical field of rail transit oxygen supply control, and discloses a variable frequency cooperative control device and method for a membrane separation oxygen generation system of a plateau motor train unit, and the device comprises a variable frequency drive module, a multi-parameter sensing module, a cooperative control module and a redundancy protection module. The variable frequency driving module supports dual-mode operation of AC380V normal power supply and DC110V emergency power supply; the multi-parameter sensing module collects key parameters such as altitude and oxygen concentration in real time; the cooperative control module adopts a double-MCU redundancy design, and dynamically adjusts frequency conversion parameters through a working condition recognition algorithm and PID closed-loop control; and the redundancy protection module realizes double-circuit power supply seamless switching, fault diagnosis and smoke and fire linkage protection. The plateau adaptability, the control precision, the energy-saving effect and the operation reliability of the oxygen generation system of the plateau motor train unit are remarkably improved, and it is ensured that the oxygen concentration of a passenger room is stabilized within the target range of 23.5%-25.0%.

The present application relates to the technical field of conductive slip ring processing control, and discloses a multi-station processing intelligent production control system for conductive slip rings, comprising a servo pressure connection device, a multi-temperature zone curing device, an electrical performance testing device, a conveying mechanism, a material carrier and a main control unit. The main control unit collects time sequence mechanical and displacement signals in the pressure connection stage and synthesizes a predicted deformation vector; collects time sequence dielectric coupling impedance signals in the curing stage to determine a gelation characteristic moment and a compensation time window, calculates target temperatures for each temperature zone according to the predicted deformation vector and outputs temperature distribution control instructions; collects time sequence dynamic contact resistance signals in the testing stage and extracts harmonic characteristics, and performs thermal compensation response model identification and parameter correction. Through the present application, a feedforward compensation and closed-loop control mechanism between the pressure connection, curing and testing processes is established, deformation caused by mechanical residual stress is compensated, and contact resistance fluctuation of the finished conductive slip ring is reduced.

The utility model relates to the field of water sample collection, in particular to natural water area water sample sampling equipment capable of stratified sampling, which comprises a floating object, the lower end of the floating object is fixedly connected with a traction rope, the lower end of the traction rope is fixedly connected with an adjusting assembly, and the lower end of the adjusting assembly is in threaded connection with a water taking device. The multiple adjusting assemblies and the multiple water taking devices are sequentially arranged, the water taking device at the tail end is fixedly connected with a balancing weight through a traction rope, and a positioning chip is arranged in the balancing weight. The traction rope is wound on the traction wheel, so that the distance between the water taking devices is changed, the water taking depth is controlled, the number of water samples can be freely selected through a freely-detachable threaded connection mode, the water taking devices can be kept to be perpendicular through the balancing weight, the fluctuation range of the water taking devices is narrowed, and the water taking device is convenient to use. The water taking device tends to be vertical after taking water, the depth is determined through the positioning chip, and the sampling depth can be controlled more accurately by using the adjusting assembly in a matched mode.