42results about How to "Reduce the amplitude of the shock" patented technology

The invention discloses a cantilever beam robustness self-adaptation control method. An ideal cantilever beam dynamic model is designed and contains frequency signals rich enough to serve as a reference trajectory of a system, it is guaranteed that the actual cantilever beam trajectory can track the reference trajectory for the whole self-adaptation control system, an ideal dynamic property is realized, and compensation of manufacturing errors and environment disturbance is achieved. The parameters of a cantilever beam are taken as unknown system parameters, a parameter error vector theta is formed, a slip form function is designed, the derivative of the slip form function is made to be zero, an equivalent controller is obtained, a feedback term and a robustness term serve as an input signal on this basis, the self-adaptation rule of the parameter theta of the controller is designed based on the Lyapunov method, the stability of the system is guaranteed, tracking error is converged to zero, and all the parameters are converged to true values.

The invention provides a method for determining the optimal operational number of variable-frequency pump units. The method comprises the following steps of drawing a flow-efficiency curve chart containing different operational numbers N of the variable-frequency pump units, and obtaining a theoretical switching node AN,N+1(QN, eta N), wherein N is a continuous integer greater than or equal to 0, and when N is greater than 1, the variable-frequency pump units are parallel variable-frequency pump units; within the range of QN+/-5%QN, performing trial running on two groups of variable-frequency pump units, with the operational numbers of N and N+1 respectively by the same flow value, and obtaining a switching node when the corresponding power PN' and PN+1' is same, wherein the switching node is an actual switching node AN,N+1'(QN', eta N'); and if the total flow Q of the variable-frequency pump units in actual operation is greater than or equal to QN' and less than or equal to QN+1', the optimal operational number of the variable-frequency pump units is N+1. Correspondingly, the invention furthermore provides a method for controlling the increment or reduction of the optimal operational number of the variable-frequency pump units to solve the problems of low efficiency and high energy consumption in a method for determining the number of variable-frequency pump units and a method for controlling the increment or reduction of the number of variable-frequency pump units in the prior art.

The invention relates to a method for improving the transient stability of a system by combining a crowbar circuit and an energy storage device. The method is applied to a multi-machine system with afan; and a rotor-side crowbar protection circuit is employed and a superconducting energy storage device is installed at the exit of a wind power plant. The method comprises: when the system works normally, the superconducting energy storage device works in a work mode of stabilizing output fluctuation of the fan; when a short-circuit fault occurs at the system, the voltage at the grid-connected point of the fan is reduced, the rotor current reaches a set value, the rotor-side crowbar protection circuit starts to work, and the work mode of stabilizing output fluctuation of the fan is changed into a work mode with a fault after the superconducting energy storage device detects a crowbar signal change; the superconducting energy storage device starts detecting a power angle difference signalbetween two synchronous machines of the two-machine systems; and when the absolute value of a difference between a power angle difference signal at a current time and a power angle difference signalat a previous time is larger than a set value epsilon, the superconducting energy storage device works continuously in the work mode with a fault.

The invention provides a direct-current speed regulation system where a prediction PI algorithm and a combined integral link are combined. The system is characterized in that the system comprises the combined integral link and a prediction PI controller which are connected in series; an input voltage signal is filtered through the combined integral link so that the input voltage signal can ascend uniformly; an output signal of the combined integral link is conveyed to the prediction PI controller, an output signal of the prediction PI controller is conveyed to a direct-current motor, and an output value of the direct-current motor is fed back to the input end of the prediction PI controller. The control strategy where the combined integral link and the prediction PI algorithm are combined, average filtering is performed on an input signal so that a deviation voltage can not become large suddenly in the starting process, and a current limiting effect is achieved; the prediction PI controller can effectively control the stable and dynamic performance of the system. On the basis of current limiting protection, rapidity of the system is obviously improved, the stable performance and the anti-interference capacity of the system are excellent, and meanwhile the anti-interference capacity and robustness are high.

The invention discloses a maximum power tracking method for a vehicle waste heat power generation system. The three-stage maximum power tracking method combines a constant voltage method and a small-step-size hysteresis comparison method; according to the first stage, the constant voltage method is used for rapidly tracking the position nearby the maximum power point of a temperature difference power generation system; according to the second stage, the small-step-size hysteresis comparison method is adopted for accurately tracking the maximum power point of the temperature difference power generation system; according to the third stage, a timer is applied for performing timing skipping, the system collects open-circuit voltage again for tracking the maximum power, and therefore rapid maximum power point tracking and high-precision maximum power point operation are achieved. The problem that oscillation, misjudgment and the like are caused near the maximum power point according to a conventional perturbation and observation method can effectively solved, the tracking speed is increased, the tracking precision is improved, and rapid high-precision maximum power tracking operation of the vehicle waste heat power generation system is achieved.

According to the embodiment, the invention provides a heat-preserving control method of an electric kettle and the electric kettle. The method comprises the following steps: detecting temperature of liquid in the electric kettle when the electric kettle is under a state that a heat-preserving function is opened; and controlling the electric kettle to intermittently heat the liquid when the temperature is less than a first preset temperature until the temperature of the liquid is greater than or identical to a second preset temperature, wherein the second preset temperature is greater than or identical to the first preset temperature. According to the embodiment, different from a mode of implementing heating continuously at full powder, the intermittent heating is slow in temperature-rising speed; therefore, the embodiment can avoid the rise of a great amount of bubbles, and a phenomenon that a great mount of bubbles appear continuously is prevented, so that an oscillating amplitude of the liquid in the electric kettle is reduced, the generation of noise is relieved and influence to user's work and life is prevented.

The invention discloses an output shaft cooling and lubricating device for an axial flow fan. The device comprises a cylinder body, wherein a rotating motor is horizontally arranged in the center of the inner part of the cylinder body, fan blades are vertically arranged on one side of the rotating motor, the rotating motor is rotationally connected with the fan blades through a power output shaftin the center of the side wall of the rotating motor, a protective sleeve is arranged around the outer wall of one end, close to the rotating motor, of the power output shaft in a surrounding mode, aspiral copper pipe is arranged around the outer wall of the protective sleeve in a surrounding mode, and protective nets are vertically and fixedly connected to the two sides of the cylinder body. According to the output shaft cooling and lubricating device for the axial flow fan, heat of the protective sleeve is absorbed through cooling liquid in the spiral copper pipe, and a second conical geardrives spiral blades to rotate through a first conical gear so that liquid flowing in the interior can be further achieved; and in addition, a surrounding water pipe is located at an air outlet, the heat can be taken away through flowing air so that cooling of the cooling liquid can be achieved, and meanwhile, a second rotating rod drives a rubber block to rise, and therefore the device has the advantages of efficient cooling and automatic lubrication.

The invention discloses a Chinese humor classification model based on reverse translation, and belongs to the field of natural language processing, and comprises S1 a text input layer, S2, a BERT embedding layer; s3, a Chinese phonetic alphabet feature embedding layer; s4, a text part-of-speech feature embedding layer; s5, a feature fusion layer; s6, a BiGRU layer; s7, a full-connection layer, wherein the full-connection layer finally completes classified output of Chinese text humor. The method has the beneficial effects that on the basis of a method of combining a reverse translation technology with a linguistic humor theory, a basic model BERT-BiGRU-Softmax is proposed to perform classification research on Chinese text humor, different humor features are gradually added into the model, a feature fusion model BERT + POS + Homophony-BiGRU-Softmax is realized, and the model has an effect on finally judging whether the Chinese text is humor or not.

The invention relates to a sectional type guaranteed cost shape control method for cold-rolled steel strips, comprising the following steps of: considering the saturation characteristics of actuators of a six-roller cold-rolling mill by a sectional type multivariable optimization control indicator function, wherein the actuators comprise a roll inclining device, a working roll bending device, an intermediate roll bending device and other shape regulation and control devices, and the saturation characteristics of the actuators are respectively the maximum plus-minus strokes and the limit physical positions of the roll inclining device and the roll bending devices; calculating the control regulating quantity when the indicator function achieves the minimum value by solving the local deviation of the indicator function based on the sectional condition; based on the saturation physical characteristics of all the actuators of the six-roller cold-rolling mill, checking and correcting the control regulating quantity acquired by calculating for the first time; and performing optimization calculation on the regulating quantity of the actuator which does not achieve the saturation state, thus exerting the maximum regulation and control ability of the rolling mill to eliminate the shape deviation, and acquiring a cold-rolled steel strip product of high quality. The sectional type guaranteed cost shape control method also optimizes the cost for rolling process control.

The invention provides an engine oil pan. The engine oil pan comprises an oil baffle and a guide pipe, wherein the oil baffle is fixed to an inner cavity of a shell body of the engine oil pan, dividesthe inner cavity of the shell body into a shell body large end area and a shell body small end area and can block most lubricating oil in the shell body large end area, so that the engine oil pan isin an inclined state, an oil suction port can suck the oil, a first guide pipe end of the guide pipe is fixedly connected to a through hole formed in the oil baffle, in addition, the first guide pipeend is provided with a one-way valve allowing the lubricating oil to pass through in a one-way mode, and a second guide pipe end of the guide pipe extends to the bottom of the shell body large end area, so that the guide pipe can guide the lubricating oil in the shell body small end area into the shell body large end area through the one-way valve.

The invention belongs to the technical field of building construction, and discloses a steel column pulling auxiliary device and a pulling method.The steel column pulling auxiliary device comprises a connecting piece and a support, the support is detachably connected to the first position of the bottom end of a to-be-pulled steel column through the connecting piece, and in the initial state of pulling, the support is detachably connected to the second position of the bottom end of the to-be-pulled steel column through the connecting piece; the edge, abutting against the placing face, of the bottom end of the to-be-pulled steel column is an abutting edge, and the first position and the abutting edge are arranged in a spaced mode. The steel column pulling method comprises the steps that the support is installed at the bottom end of a to-be-pulled steel column through the connecting piece; hooking a steel wire rope connected with the to-be-pulled steel column by utilizing hoisting equipment; hoisting equipment is hoisted upwards; in the lifting process, the support makes contact with the placing face till the steel column to be lifted is perpendicular to the placing face; the steel column to be pulled is vertically and upwards lifted, and the support is disassembled; and the to-be-pulled steel column is put down to the placing surface. According to the invention, the oscillation amplitude of the to-be-pulled steel column during pulling can be reduced, and a batten can be saved.

An embodiment of the invention discloses a radio frequency signal receiving circuit, a circuit board, a chip and a terminal. The radio frequency signal receiving circuit comprises an antenna circuit,a first filter circuit, a switch circuit, a second filter circuit, a low-noise amplifying circuit and a mixing circuit; the second filter circuit includes a first sub-filter circuit and a second sub-filter circuit; the first sub-filter circuit includes first filter device F1, second filter device F2, third filter device F3 and fourth filter device F4; the first end of the first filter device F1 isconnected with the first end of the first filter device F2, the second end of the first filter device F1 is connected with the first end of the first filter device F3, the second end of the first filter device F3 is connected with the first end of the first filter device F4, and the second end of the first filter device F4 is connected with the second end of the first filter device F2. The radiofrequency signal receiving circuit enables signal processing effect of a modulator to be improved to certain degree.

An auxiliary balance device for the spin-drying barrel of a lead pendant type washing machine, which is composed of a lead pendant connected with a wire post; a section of the thread post is connected to the shaft head of a pulley installed at the lower end of the washing machine spin-drying barrel, and a lead pendant is connected to the thread post. The lead pendant is connected into one body through the thread hole and the wire post; the lead pendant can effectively lower the center of gravity of the spin-drying bucket when the washing machine spins, and has a compensating effect on the eccentric rotation of the spin-drying bucket.

The invention discloses a voltage pre-stabilizing circuit and a power supply. The pre-voltage-stabilizing circuit comprises a controllable voltage-stabilizing source, a first voltage dividing module, a second voltage dividing module, a voltage limiting module, a first power supply input end, a second power supply input end, a first power supply output end and a second power supply output end, the first end of the first voltage dividing module is electrically connected with the first power supply input end, the second end of the first voltage dividing module is electrically connected with the first end of the controllable voltage stabilizing source, and the voltage dividing output end of the first voltage dividing module is electrically connected with the first end of the voltage limiting module; the second end of the controllable voltage stabilization source is electrically connected with the second power supply input end, and the reference end of the controllable voltage stabilization source is electrically connected with the voltage division output end of the second voltage division module; the second end of the voltage limiting module is electrically connected with the first end of the second voltage dividing module and the first power supply output end; and the second end of the second voltage division module is electrically connected with the second power supply input end and the second power supply output end. According to the invention, the controllability and precision of the output voltage of the pre-voltage-stabilizing circuit can be improved.