35results about How to "Reduce the degree of non-linearity" patented technology

The invention belongs to the technical field of vibration and noise control and relates to a relatively-high-applicability passive isolation technology for ultralow-frequency vibration. In order to effectively solve the problem between the low-frequency vibration transmissibility and the high-frequency vibration attenuation rate of the vibration isolator, the invention provides the stiffness-adjustable magnetic vibration isolator with quasi zero stiffness, which adopts rectangular permanent magnets generating negative stiffness and an elastic capsule providing positive stiffness; and when a load is changed, the working position of the elastic capsule is controlled unchanged, the positive stiffness of the elastic capsule is changed because the pressure inside the elastic capsule is changed, and then, the negative stiffness is matched with the positive stiffness through regulating the distance among the rectangular magnets, so that the stiffness-adjustable magnetic vibration isolator with quasi zero stiffness is adaptable to vibration isolation objects with different weights. The stiffness-adjustable magnetic vibration isolator with quasi zero stiffness is simple in structure, convenient to mount, adjustable in bearing capacity, excellent in vibration isolation property, compact in structure, light in weight and suitable for popularization and application.

The invention discloses a novel negative stiffness structure capable of providing a stable negative stiffness value, and belongs to the technical field of low-frequency vibration isolating. The novelnegative stiffness structure comprises a supporting seat, a base and at least one pair of negative stiffness units. Each negative stiffness unit comprises a connecting rod transmission mechanism, an upper magnet, a middle magnet and a lower magnet, wherein the upper magnet, the middle magnet and the lower magnet are sequentially arranged at intervals from top to bottom in a corresponding mode, andthe middle magnet repels the upper magnet and the lower magnet. Each connecting rod transmission mechanism comprises an upper connecting rod, a middle connecting rod and a lower connecting rod. The top ends of the upper connecting rods are connected with the supporting seat in a hinged mode, and the bottom ends of the upper connecting rods are connected with the middle connecting rods in a hingedmode. The middle connecting rods are fixedly connected with the middle magnets. The top ends of the lower connecting rods are connected with the middle connecting rods in a hinged mode, and the bottom ends of the lower connecting rods are connected with the base in a hinged mode.

The invention discloses an internal sequence heterogeneous material topological optimization method specifically comprising the steps of 1, building a finite element model of a design domain, initializing parameters in an algorithm, sorting materials in a descending order according to modulus sizes, and meanwhile setting an outer iteration serial number Nout to be equal to 1, and setting an inner iteration serial number i to be equal to 1; 2, after the step 1, finding an optimal solution for an i-th sub-problem; 3, setting the i to be equal to m, which means that volume constraints of all materials are met, continuing to execute the next step, and entering to the step 4; 4, after the step 3, judging whether to converge; if a convergence condition is met after computing, continuing the step 5; and otherwise, setting the Nout to be equal to Nout+1, and then returning to the step 2; and 5, ending, thus completing optimization. According to the internal sequence heterogeneous material topological optimization method provided by the invention, the phenomenon that a heterogeneous material optimization model is difficult to converge due to an overhigh nonlinear degree can be avoided.

The present invention relates to a method for evaluating the reliability of engineering structure based on a distributed hybrid collaborative agent model, comprising the following steps: decomposing the engineering structure into multiple subsystem layers; selecting random input variables of engineering structure sub-objects in the lowest subsystem layer, And obtain the input samples of random input variables; establish the finite element model of the engineering structure sub-object in the lowest subsystem layer, and obtain the output indicators of each engineering structure sub-object; establish different types of agents for the engineering structure sub-object in the lowest subsystem layer Model, the proxy model with the highest precision is the optimal proxy model of the sub-object of the engineering structure at the lowest subsystem layer, and the optimal proxy model of the engineering structure is obtained layer by layer for reliability evaluation. Compared with the prior art, the present invention decomposes the overall complex structure into sub-objects distributed in multiple levels, reduces the number of sub-object parameters, reduces the degree of nonlinearity, and reduces the amount of calculation, which is conducive to improving the approximation accuracy and simulation speed of the engineering structure proxy model .

The invention relates to an adaptive alignment method under the fixed earth coordinate system, the steps: (1) select the earth fixed coordinate system as the navigation coordinate system, and use the additive quaternion of position error, velocity error and attitude misalignment angle The numerical error is used as the system state variable. (2) The state equation consists of position error equation, linearized velocity error equation and attitude error equation. (3) Using the velocity and position observation information of the GNSS receiver to construct the observation equation. (4) Design an adaptive linear Kalman filter algorithm for initial alignment. The invention does not require static leveling, the amount of real-time calculation is small, the alignment process converges quickly, and the alignment accuracy is high.

The invention relates to a process optimization system for improving the stability of the manufacturing quality of automobile coverings which is used in the technical field of automobile manufacturing, wherein, a GUI model is a graphic user interface and used for realizing the interaction between users and other models; a variable attribute model saves attribute of controllable process, attributeof noise factor and attribute of quality inspection indicators which are input by the users; a variable filtering model filters the controllable process and the noise factor that impose most significant impact on the quality inspection indicators; a response surface modeling model builds a response surface model among the controllable process, the noise factor and the quality inspection indicator; a noise factor random attribute model saves noise factor random attribute input by users; a random response surface modeling model builds a random response surface model between the average value and standard balance of the controllable process and the quality inspection indicators; and a process optimization model adopts multiple-target optimization algorithm for processing so as to obtain optimum process conditions. The process optimization system can realize the improvement of the stability of the manufacturing quality of the automobile coverings and the reduction of the defective index.

The invention discloses a multi-phase structure of a two-channel orthogonal mirror image filter bank and a coefficient design method of thereof. At present, most known two-channel QFMB design methodsare optimization design of prototype filter coefficients, and do not pay much attention to reduction of hardware implementation complexity of a QMFB structure. The multi-phase structure of the two-channel orthogonal mirror image filter bank comprises an H0 module, an M (z) module, q modules, a module connecting part, a main input port Input, a main output port Output0 and a main output port Output1. According to the multi-phase structure of the two-channel QMFB analysis filter bank part provided by the invention, a traditional QMFB prototype filter coefficient is converted into a form of an extrapolation pulse response filter, and LU decomposition is adopted, so that more 0 and 1 exist in the coefficient, and multiplier and adder resources are saved.

The invention discloses a corrugated tube encircling gas inertial container, which comprises a cylindrical tank body, a corrugated pipeline, a piston, a piston rod, a baffle plate and a horizontal baffle. The cylindrical tank body is provided with a horizontal baffle plate. The partition divides the cylindrical tank into two independent and disconnected cavities. The upper cavity is the cylinder and the other is the stroke chamber. The piston is fixed on the piston rod, the baffle is fixed on the bottom surface of the piston rod, and the piston The upper end of the rod protrudes from the center of the top surface of the cylinder, so that the piston is located in the cylinder, the baffle is located in the stroke chamber, the corrugated pipe is fixed on the outer wall of the cylindrical tank, and the two nozzles of the corrugated pipe communicate with the cylinder. A section of liquid is housed in the corrugated pipe, and this section of liquid can only flow back and forth in the corrugated pipe and cannot enter the cylinder. When the inertia works, the piston moves back and forth in the cylinder. The baffle plays the role of restricting the relative displacement of the two end points, which can prevent the liquid in the corrugated tube from entering the cylinder so that the inertial capacity cannot work normally.

The invention discloses a stochastic optimization method for output and topology of AC / DC system units, the steps include: S1. constructing an optimization model; S2. setting the state of all branch switches in the optimization model to a closed state; S3. setting step S2 The optimized model obtained after processing is decomposed into multiple sub-models, and each sub-model contains only one N-1 fault or does not contain any faults; S4. Solve each sub-model separately to obtain the solution result of the first-stage optimized model; S5. According to the solution results of each sub-optimization model, the effective switch set is obtained; S6. In the optimization model constructed in step S1, the state of the remaining switches other than the effective switch is set to the closed state, and the second-stage optimization model is obtained; S7. Solve the second The stage optimization model is used to obtain the final joint optimization results of topology structure and unit output. The invention can efficiently optimize the unit output and topology of the AC and DC system at the same time, and has the advantages of high calculation efficiency and the like.

The invention discloses a reduced-order kernel function-based high-order polynomial phase signal parameter estimation method, and aims at solving the technical problem that the existing high-order polynomial phase signal parameter estimation method is low in estimation precision. The method is realized through the following steps of: uniformly sampling white Gaussian noise-mixed high-order polynomial phase signals to obtain a phase signal sequence; constructing a reduced-order kernel function of the phase signal sequence; carrying out spline interpolation on the phase signal sequence to obtain a non-uniform interval sequence; calculating a reduced-order signal sequence; carrying out fast Fourier transform on the reduced-order signal sequence; calculating estimators of to-be-estimated parameters in the phase signal sequence and outputting the estimators; demodulating the phase signal sequence to obtain a reduced-order demodulated sequence; updating the phase signal sequence, circularly constructing the reduced-order kernel function, calculating estimators of the to-be-estimated parameters in the updated phase signal sequence in sequence and outputting the estimators; and updating the reduced-order signal sequence to obtain a first-order phase signal sequence, calculating estimators of first-order parameters and outputting the estimators.

The invention relates to a graphene field effect transistor, in particular to a manufactured method of a transistor based on the graphene field effect. According to the method, metal gas source Ga ions are used for illuminating the surface of graphene, hole doping is carried out on the graphene, the Ga ions can lead pressure stress into the graphene, and the heat generated by illumination has an annealing function for the graphene. For the transistor based on the modified graphene field effect, the annealing function relieves the output nonlinearity of the field effect transistor, the led-in pressure stress opens the energy band structure of the graphene, the switch ratio of the graphene field effect transistor is improved, and the application of the field effect transistor in a logic circuit is promoted.