66 results about "Chaotic oscillations" patented technology

The invention relates to a random number generating system and a random number generating method, wherein the random number generating system comprises super-lattice noise source, a power supply module, a quantifying and coding module and an output module; the super-lattice noise source generates a random noise simulating signal; the power supply module is electrically connected with the super-lattice noise source so as to provide offset voltage needed by the super-lattice noise source for processing chaotic oscillation spontaneously; the quantifying and coding module is electrically connected with the super-lattice noise source and the output module respectively and is used for quantifying and coding the random noise simulating signal so as to generate a random number code stream; and the output module outputs the random number code stream. The invention can obtain a random number sequence including true randomness and high quality; a generated speed can reach to more than Gbit/s; and the invention is applied to fields such as data encryption, key management, security protocol, digital signature, identity authentication and the like.

A washing machine includes a tub; a drum rotatably disposed inside the tub; and an ultrasound generator configured to emit ultrasonic waves to washing water loaded in the drum, and to generate bubbles. The ultrasound generator applies ultrasonic energy to the washing water to cause chaotic oscillation of the bubbles.

The invention discloses a fixed time dynamic surface high-order sliding-mode suppression method for chaotic oscillation of a power system. The suppression method comprises the steps of (1) determining the reactive power of the to-be-compensated power system; (2) establishing a mathematical model of a current source type static synchronous compensation controller, and determining the output and reference value of the current source type static synchronous compensation controller; (3) determining a control target value, wherein the output can achieve an adjacent domain with an arbitrarily small reference value within finite time, and the upper bound of the convergence time does not depend on the initial value; (4) designing a fixed time dynamic surface high-order sliding-mode surface and control law to realize target control; and (5) determining the control parameter of the designed control law according to stability analysis of the Liapunov function. By adoption of the method, system stability can be realized within predetermined time under any initial starting condition of the system; and in addition, a buffeting phenomenon is overcome, higher transient response is obtained, the convergence speed is accelerated and the stability of the power system is improved.

The invention discloses a fractional order characteristic driven micro electro mechanical system (MEMS) control method. The control method comprises the following steps: under the condition of considering the input hysteresis characteristic, establishing a mathematical model of the MEMS, by considering the unmeasurable variable, time-varying lagging item, uncertainty and the output constraint thereof of the system, disclosing a chaotic oscillation phenomenon of the MEMS, and constructing time-varying delay in a compensation system state through Lyapunov-Krasovskii function, and proposing a self-adaptive stabilization control scheme for fusing an extension state observer, a Chebyshev neural network, a tangent baffier function and a tracking differentiator in a frame of the backstepping. Thecontrol method has the following effects of accelerating the solving speed, improving the system transient and steady-state performance, broadening the limitation of a physica sensor, reducing the computation workload, simplifying the controller design, cancelling the requirements on the primary function center and width, reducing the dependence on the precise model, improving the precision of atraditional first-order low-pass filter, overcoming an explosion problem of the differential item and guaranteeing that the output constraint condition cannot be violated.

The invention discloses a hyperbolic function sliding-mode control-based chaotic oscillation suppression method of a power system. The chaotic oscillation suppression method is implemented according to the following steps of 1, calculating a relative error e(t) according to a relative rotor angle actual value x<1>(t) and a relative rotor angular speed ideal value x<d>(t) of a second-order interconnection dual-motor power system; 2, setting a sliding-mode controller parameter; 3, calculating a motion state of a system sliding-mode surface according to the relative error e(t) and the sliding-mode controller parameter; and 4, generating a controller output u(t) by joint efforts of the sliding-mode controller parameter and a motion state equation, making the controller output acted on a rotor of a power generator, outputting the current relative rotor angle actual value x<1>(t), forwarding to the step 1, and adjusting the controller output according to the relative error. According to the hyperbolic function sliding-mode control-based chaotic oscillation suppression method of the power system, a chaotic oscillation phenomenon generated in the interconnection dual-motor power system is rapidly and effectively suppressed by the sliding-mode controller of a hyperbolic tangent function.

The invention discloses a PMSM chaotic system neural network dynamic surface control method considering output constraints. The PMSM chaotic system neural network dynamic surface control method considering the output constraints comprises the following steps: 1) establishing a dynamic model of a PMSM system; and 2) using a kinetic model to build an adaptive dynamic surface controller; using the RBF network to approximate a nonlinear unknown term, a nonlinear term and a nonlinear damping term of the system model to overcome external disturbances; and introducing a first-order low-pass filter toreplace the derivative of the virtual control through the dynamic surface defined by a nominal motor speed of the nominal dynamic model and an ideal trajectory signal. The PMSM chaotic system neuralnetwork dynamic surface control method considering the output constraints disclosed by the invention can effectively suppress the influence of unknown parameters, chaotic oscillations and external disturbances on the system; and meanwhile, the output is constrained within a specified range, therefore, the invention has good validity and robustness.

The invention provides an implementation method of a novel chaotic oscillation circuit. According to the implementation method, a first integrator of an integrated operational amplifier U1 is used forrealizing operation of a first equation of a chaotic system; the operation of a second equation of the chaotic system is realized through a first adder and a second integrator of the integrated operational amplifier U1, a second reverse integrator of an integrated operational amplifier U2, and a first multiplier U3; and the operation of a third equation of the chaotic system is realized through asecond adder, a third integrator, a third inverter, a second multiplier U4, a third multiplier U5 and a fourth multiplier U6 of the integrated operational amplifier U2. A hidden attractor exists in the oscillation circuit, and meanwhile a coexistent attractor exists, so that a generated sequence has higher security, higher performance, and a very high reference value and a very good application prospect in the fields of chaotic signal generation, secure communication, character image encryption and the like.

The invention provides a fast suppression method of chaotic oscillation of a two-machine interconnected power system, which is suitable for the field of electrical engineering. According to the theoryof fixed time stability, combined with the traditional adaptive control and fast Terminal sliding mode control, a nonlinear controller is designed to make the control variable reach the neighborhoodwith arbitrarily small reference value in finite time, and the asymptotic stability of global fixed time at the equilibrium point is realized. It can stabilize the system in finite time without relying on the initial value. The stability time range can be guaranteed to have an upper bound, and the upper bound of the stability time can be calculated by the method provided by the invention; The method has strong robustness and anti-jamming ability. Under any initial conditions, the system can achieve global uniform asymptotic stability in a predetermined time, more effectively suppress the chaotic oscillation in the power system, and improve the stability of the power system.

The present invention discloses a chaotic oscillation control method of a brushless DC motor based on a finite time stability theory. The method comprises the following steps of 1) establishing a mathematical model of the brushless DC motor; 2) carrying out the controller design based on the finite time stability theory; 3) simulating and verifying the numerical value of the controller design based on the finite time stability theory. The advantages of the present invention are that: (1) by controlling the parameter change, a system is still located in a stable state, and has a stronger robustness; (2) compared with a general control method, a finite time stability control method has the characteristics of being simple in structure, faster in convergence speed and excellent in control performance, etc.

The invention relates to a fractional order self-sustaining electromechanical seismograph system acceleration stability control method with constraints, and belongs to the field of seismic exploration. The fractional order self-sustaining electromechanical seismograph system acceleration stability control method comprises the following steps of: S1, carrying out system modeling, which is implemented by establishing a mathematical model of a fractional order self-sustaining electromechanical seismograph system according to a Newton's second law and a Kirchhoff's law, and defining constraint conditions; S2, and designing an acceleration stability controller, wherein the design is implemented by constructing an acceleration feedforward controller and an optimal feedback controller, the acceleration feedforward controller is integrated by a molding behavior function based on a fractional order inversion method, a fuzzy wavelet neural network and a tracking differentiator, and the optimal feedback controller is formed by fusing a fuzzy wavelet neural network and an adaptive dynamic programming strategy. According to the fractional order self-sustaining electromechanical seismograph system acceleration stability control method, the boundness of all signals of a closed-loop system is ensured, the safe operation of the system under the constraint condition is ensured, and meanwhile, chaotic oscillation can be suppressed and a minimum cost function can be realized.

The invention relates to a random noise resource and a manufacturing method thereof. The random noise source comprises a two-end semiconductor superlattice device which is fixed on a microwave printed circuit board and electrically connected with the microwave printed circuit board, wherein the two-end semiconductor superlattice device comprises a semi-insulation semiconductor substrate, a first semiconductor contact layer, a semiconductor superlattice layer structure and a second semiconductor contact layer which epitaxially grow on the semi-insulation semiconductor substrate sequentially, a first contact electrode and a second contact electrode, wherein the first semiconductor contact layer, the semiconductor superlattice layer structure and the second semiconductor contact layer are made of compound semiconductor materials in the III-V cluster or II-VI cluster; and n-type impurities are doped in the first semiconductor contact layer, a potential well layer in the semiconductor superlattice layer structure and the second semiconductor contact layer respectively. Due to a solid automatic chaotic oscillation characteristic of the semiconductor superlattice device, the random noise resource with true randomness, high quality and high bandwidth is implemented; and flat broadband chaotic signals with bandwidths of greater than GHz are output.

An a system and method for chaos transfer between multiple detuned signals in a resonator mediated by chaotic mechanical oscillation induced stochastic resonance where at least one signal is strong and where at least one signal is weak and where the strong and weak signal follow the same route, from periodic oscillations to quasi-periodic and finally to chaotic oscillations, as the strong signal power is increased.

The invention provides a method for rapidly retraining harmonic oscillation of an electric power system. The method comprises the steps of at first, giving a principle of a chaos oscillation phenomenon, which occurs in a double-motor interconnected electric power system; and researching a threshold value area where the system generates oscillation and a non-linear oscillation condition by combining a Melnikov method. The method for rapidly retraining the harmonic oscillation of the electric power system is used for quickly restraining the harmonic oscillation of the electric power system by using a simplest self-adaptive controller, so that the conclusion accuracy is verified through a test.

The invention provides a rapid inhibition method for stand-alone infinite electric system chaos oscillation. The method includes the steps that a mechanism of a stand-alone infinite electric system producing a chaos oscillation phenomenon is firstly given, and a condition of the system producing the nonlinearity chaos oscillation is researched. Rapid inhibition for the stand-alone infinite electric system chaos oscillation is achieved by utilizing of the simplest self-adaptive controller, and correctness of conclusions is verified through experiments.

The invention discloses a chaotic oscillating circuit comprising a color circle inductor, a resistor, two chip capacitors and a nonlinear negative resistance circuit, wherein the resistor is a variable resistor, the nonlinear negative resistance circuit is formed by connecting two inverters in parallel in a CMOS (Complementary Metal-Oxide-Semiconductor Transistor) hex inverter chip, and the two inverters are connected end to end. The chaotic oscillating circuit has simple structure and adopts easily-obtained components, thereby being easy to realize; meanwhile, the chaotic oscillating circuit presents chaotic oscillating phenomena difficult to be observed in daily life and has relatively higher oscillation frequency; and in addition, various chaotic phenomena and gradual changes among the various chaotic phenomena in double-eddy chaotic oscillation can be observed only by simply adjusting the value of the variable resistor.

The invention relates to a four-order power system chaotic control method of a bidirectional optimization BP neural network sliding mode variable structure. On the basis of a four-order power system chaotic mathematical model, the power system chaotic oscillation is controlled by using a control method combining a bidirectional optimization BP neural network and sliding mode variable structure control. In the neural network, the excitation function used in the forward direction and the learning rate used in the reverse direction of the algorithm are optimized respectively, so the buffeting phenomenon of sliding mode variable structure control is effectively suppressed, and the chaotic oscillation control is more ideal; compared with the traditional sliding mode variable structure control,the method keeps excellent characteristics of the BP neural network and the sliding mode variable structure control, and on the premise of overcoming the false saturation phenomenon of the neural network, the method improves the generalization ability and reasonably accelerates the learning process, weakens the buffeting phenomenon of the sliding mode variable structure control more effectively, and enables the chaotic control of the power system to be better.

The invention relates to a self-adaptive event trigger control method of a permanent magnet synchronous generator coupling chaotic network system, and belongs to the field of permanent magnet synchronous motors. The method comprises: S1, establishing a dynamic model, wherein K identical permanent magnet synchronous generators, resistors and capacitors are connected to form a coupling network to describe an actual power generation system; S2, performing kinetic analysis on the dynamic model; and S3, in an inversion control framework, estimating unknown items of the dynamic model by using an interval type 2 fuzzy neural network, ensuring the boundaries of the system state through a cosine barrier function, achieving stable control in finite time through an improved saturation function reaching law and a Nussbaum type function, and approaching the unknown function of the dynamic model; and adopting an event triggering strategy and a second-order tracking differentiator to save calculation and communication resources, so that the problem of item explosion related to the inversion process is avoided. According to the method, the inherent chaotic oscillation related to the permanent magnet synchronous generator coupling chaotic network system can be completely suppressed.

A broadband chaotic oscillation circuit comprises a radio frequency triode, a frequency selection network module, a bias module and an output module. Wherein the frequency selection network module isconnected with the base electrode of the radio frequency triode to form a Colpitts oscillator, the bias module is connected with the base electrode and the emitter electrode of the radio frequency triode, and the collector electrode of the radio frequency triode is a signal output node and is connected with the output module. The circuit is based on a Colpitts oscillating circuit, and utilizes double-resistor voltage division bias to supply power to a base electrode of a radio frequency triode. And the resonant network positioned at the base electrode and the emitter electrode is matched withthe radio frequency triode to realize generation of chaotic signals. The signal output node is located at the collector electrode, the load resistor of the output module and the inductor connected with the collector electrode in series form an RLC series resonance network, the resonance network does not affect the circuit state, the signal frequency spectrum can be improved by adjusting the resonance frequency, and then broadband signal output is achieved. The circuit has high load capacity, can generate continuous broadband chaotic signals, has flat signal frequency spectrums, and is suitablefor broadband radio frequency wireless communication.

The invention relates to a fuzzy finite time optimal synchronous control method of a fractional order permanent magnet synchronous generator, and belongs to the technical field of generators. A synchronous model between the fractional order driving permanent magnet synchronous generator and the fractional order driven permanent magnet synchronous generator with capacitance-resistance coupling is established. Rich dynamic behaviors including chaotic oscillation of the system are fully revealed through dynamic analysis, and stability and non-stability boundaries are given through a design numerical method. And then, under the framework of a fractional order backstepping control theory, a fuzzy finite time optimal synchronization control scheme fusing the hierarchical type-2 fuzzy neural network, a finite time command filter and a finite time preset performance function is provided. Stability analysis proves that all signals of the closed-loop system are bounded under the condition that the cost function is minimum. Finally, a numerical simulation result verifies the feasibility and superiority of the method.

The present invention relates to a non-linear system, and in particular, to a spherical five-item quasi-periodic oscillator and a circuit. Currently, a currently common oscillator is a period oscillator, and a chaotic oscillator can generate a periodic oscillation system and a quasi-periodic and chaotic oscillation system with different parameters, but a system that only generates a quasi-periodic oscillator is not yet found. The present invention proposes a five-item spherical quasi-periodic oscillation system, so that a type of the oscillator is increased, thereby providing a new selection for the oscillator applied to engineering practice.

The invention relates to the technical field of micro-electronics and solid-state electronics, in particular to a current mode chaotic oscillator. The current mode chaotic oscillator comprises a first Venn type current mode sine oscillation circuit, a second Venn type current mode sine oscillation circuit and a nonlinear link. After passing through the nonlinear link, output signals of the first Venn type current mode sine oscillation circuit are coupled with output signals of the second Venn type current mode sine oscillation circuit, so that continuous chaotic oscillation signals are obtained. The current mode chaotic oscillator is suitable for being obtained on a single integrated circuit chip and is compact in structure, low in power consumption, and low in voltage. Due to the fact that a current conveyer is used as an active device, the current mode chaotic oscillator has the advantages of being large in frequency bandwidth, high in speed, resistant to noise, and high in practical value. Meanwhile, due to the fact that the symmetry of circuit design of the current mode chaotic oscillator is quite high, the chaotic characteristics of the output signals have high robustness to process change.

The invention discloses a digital-analog hybrid chaotic circuit including a logic device, and an operation method thereof. The chaotic circuit composed of a difference equation and a sign function is realized in a way that the difference equation is realized by use of an analog circuit and the sign function is realized through a logic gate circuit. An analog circuit portion is composed of such routine analog devices as a resistor, a capacitor, an operational amplifier and the like. A digital circuit portion is composed of a signal formation module, a logic operation module and a unipolar-bipolar signal conversion module, wherein the logic operation module is composed of such routine digital circuits as a NOR gate, a NAND gate and the like. Sign function operation in a chaotic system is realized by use of the digital circuit portion, and chaotic oscillation of an actual circuit is realized through cooperation with the analog circuit. According to the invention, digital devices are embedded in an analog chaotic circuit, sign operation is completed, different chaotic systems can be realized in the same circuit through switching different logic operation circuit modules, and the accuracy, the versatility and the applicability are quite high.