45 results about "Random switching" patented technology

The invention discloses a satellite route management and control switching method and system, and belongs to the field of satellite communication, and the satellite route management and control switching method comprises the following steps: monitoring satellite signal quality, collecting satellite data, judging whether nodes need to be switched or not, and if yes, switching the nodes; the triggering condition comprises that the signal quality decline is lower than a threshold value, and the communication equipment is about to break away from the current satellite network coverage range; when nodes need to be switched, an optimal switching target is selected from the candidate nodes, the signal quality of the optimal switching target is judged, and if the signal quality meets the use requirement, compared with the prior art, the method has the beneficial effects that when the coverage edge overlapping area of the multiple satellite networks is too small and the signal quality is judged to be poor, the optimal switching target is selected from the candidate nodes; according to the method, the switching node is limited, the random switching of the node is not allowed in the set time, the set time can be adjusted according to the actual condition, different conditions are matched, and the problems of communication quality degradation, network resource waste, terminal energy consumption increase and the like are reduced.

The invention relates to a true random number generation circuit and a chip, the true random number generation circuit comprises a clock signal generation module and a sampling module, the output end of the clock signal generation module is connected with one input end of the sampling module; the clock signal generation module is used for randomly switching the input current or voltage of the clock signal generation module according to a random signal so as to generate a jitter clock signal, and the sampling module is used for sampling a target clock signal according to the jitter clock signal so as to generate a true random number. The switching action of switching the input current or voltage can introduce jitter, and the input current or voltage is randomly switched through the random signal, so that the input time of the input current or voltage is random, the jitter degree of the generated jitter clock signal can be effectively increased, and the randomness of the generated true random number can be effectively enhanced; and the quality of the true random number can be effectively improved.

The invention discloses an event-triggered adaptive fixed time control method for a random nonlinear switching system. The method comprises the following steps: constructing a model of the random nonlinear switching system; introducing an event triggering mechanism; designing a fixed time control strategy; and designing an event-triggered fixed-time adaptive controller based on a backstepping method design framework. According to the event-triggered adaptive fixed time control method for the random nonlinear switching system, an event-triggered control strategy is adopted to reduce the communication burden of the system. A new controller is stably constructed by using fixed time, and the upper bound of convergence time is irrelevant to initial conditions; meanwhile, by introducing nonlinear mapping, a random nonlinear system with symmetric and asymmetric output constraints is converted into a new unconstrained system, and random switching of the control system is realized by using a switching signal.

The utility model relates to the technical field of monocular night vision device supports, and particularly discloses a monocular night vision device left and right eye switching support which is easy to operate and comprises a positioning plate, L-shaped plates are connected to the two sides of the top of the positioning plate, an arc-shaped mounting plate is fixedly connected to one side of each L-shaped plate, and an adjusting groove is formed in the positioning plate. A sliding block is slidably connected to the interior of the sliding groove, a square block is fixedly connected to the top of the connecting block, a monocular night vision device body penetrates through the interior of the round hole, an adjusting knob is in threaded connection with the interior of the threaded hole, and an extrusion block is fixedly connected to the bottom end of the adjusting knob. According to the monocular night vision device, the square block, the adjusting knob, the extrusion block, the sliding groove, the connecting block, the compression spring, the adjusting plate and the fastening knob are matched for use, so that the monocular night vision device body can be freely switched between the left eye and the right eye during use, the operation mode is simple during switching, and workers can conveniently use the monocular night vision device; and the height of the arc-shaped mounting plate can be adjusted as required.

The multifunctional multi-station flexible cleaning machine comprises an installation support, installation plates are fixedly installed on the two sides of the installation support at the corresponding heights, a plurality of independent lifting adjusting devices are correspondingly installed on the installation plates, and the independent lifting adjusting devices are correspondingly provided with different cleaning assemblies. Through the structural arrangement, the cleaning machine has the characteristics of multiple functions and multiple stations, and different cleaning procedures are set, so that different products can be randomly switched, or the stations can be exchanged according to different product objects, even more cleaning stations can be added, and different workers can be conveniently selected to clean the surfaces of the products.

The present application relates to a kind of multi-vehicle random switching flexible total assembly system for medium and large-sized passenger cars, including assembly platform and upper piece area, the upper piece area of assembly platform two sides respectively stores the side wall of two sides of the same vehicle;Upper piece area includes upper piece track and storage track, storage track is located in the two sides of upper piece track, upper piece track is equipped with assembly sliding table and welding robot sliding table, storage track is equipped with clamp, mobile tooling table and traction dolly, traction dolly connects mobile tooling table, clamp is fixed on mobile tooling table and connects two-way pneumatic-electric switching component, clamp clamps side wall and keeps clamping state when clamping side wall.Compared with prior art, the present application has the advantages that the clamp is fixed on the mobile tooling table and connected with the two-way pneumatic-electric switching component, the clamp is provided with air supply and power, the power and control signal of the clamp are not interrupted during transportation, the clamp keeps clamping state, the position of the side wall does not change, and the accuracy of the side wall assembly position is ensured.

The application provides a multi-target switching device, which comprises a target frame, a target plate, a driving mechanism and a base, the target frame comprises two power edges and two fixed edges; the target plate comprises an upper target plate and a lower target plate; one end of the first fixed edge is hinged to the base, and the other end is hinged to one end of the first power edge; the first fixed edge is arranged in a vertical state, can be tilted backward and fixed back; the second power edge is located in front of the first fixed edge, one end of the second power edge is connected to the driving mechanism and can rotate around the driving mechanism; the two ends of the second fixed edge are respectively hinged to the other ends of the two power edges; the upper target plate is fixedly connected to the second fixed edge, and the lower target plate is fixedly connected to the second power edge; when the two power edges are in a vertical state, the upper target plate and the lower target plate are located in the same plane; a shifting block is arranged on the second power edge. The application can independently realize random switching of the tactical posture of a combat unit and more realistically simulate the tactical action of the combat unit in actual combat.

The invention discloses a switching method and device without a random access process, a base station and a storage medium, and belongs to the technical field of wireless communication, the method comprises the following steps: receiving a switching request sent by a source station, the switching request comprising first spatial position information of a to-be-accessed terminal relative to a target station, and according to recorded second spatial position information of each successfully switched reference terminal relative to the target station, determining whether the to-be-accessed terminal satisfies an RACH-LESS switching condition, if the to-be-accessed terminal satisfies the RACH-LESS switching condition, sending RACH-LESS switching request confirmation information to the source station based on the switching configuration information of the reference terminal, and if the to-be-accessed terminal satisfies the RACH-LESS switching condition, sending the RACH-LESS switching request confirmation information to the source station. The to-be-accessed terminal executes a non-random switching process at the target station based on the received RRC reconfiguration connection request message sent by the source station, and the RRC reconfiguration connection request message carries switching configuration information. According to the invention, the switching time delay and the RACH resource overhead can be reduced, and the RACH-LESS switching success rate can be improved.

The present invention relates to the technical field of intelligent locks, and discloses a method, device, computer device and medium for password verification and unlocking of an electronic device. The method includes: detecting an unlocking operation on a display screen of the electronic device to be unlocked; displaying a password verification interface on the display screen according to the unlocking operation, wherein the password verification interface can be randomly switched to multiple password modes; obtaining a dynamic password trajectory input on the password verification interface, and determining contact interaction information and path information based on the dynamic password trajectory; verifying the contact interaction information and the path information based on dynamic restriction conditions corresponding to the current password mode to obtain a verification result, and controlling the electronic device to be unlocked to perform an unlocking operation according to the verification result. The present invention solves the problems of weak anti-attack ability and poor user experience caused by the low security of the static password mode, the difficulty for special users to remember complex passwords, and the single dynamic verification mechanism of traditional electronic devices to be unlocked.

The invention discloses a hysteresis current control method and system for a two-level grid-connected converter, and belongs to the technical field of converter control. The method comprises the following steps: fixing the switching frequency of the converter through a frequency inner ring; generating a reference square wave and collecting a switch square wave; multiplying and accumulating the two in each control step length, and taking an accumulated value as a phase discrimination result at the rising edge of a switching period to finish switching phase discrimination; comparing a phase discrimination result with a phase reference value, and processing the phase discrimination result by a PI (Proportional Integral) controller; pI output is processed and then fed back to a frequency instruction, a phase outer ring is formed through a frequency-phase integral relation, and closed-loop control of a switch phase is achieved. The technical problems that a traditional hysteresis control switch is random in phase and multi-machine parallel ripple offset cannot be achieved are solved, the advantage of dynamic performance of hysteresis control is kept, meanwhile, accurate fixing of the switching frequency and the phase is achieved, the system performance is remarkably improved, and the application scene of the system is expanded.

The present invention relates to a sliding mode control method for an inverted pendulum system based on a random communication protocol, belonging to the field of automatic control technology. The method combines sliding mode control for an inverted pendulum system based on a continuous dwell time with sliding mode control based on a random communication protocol to construct a coordinated controller. A discrete-time uncertain switching system model with a PDT switching rule is constructed, and combined with a random communication protocol scheduling mechanism, the random switching behavior of nodes accessing the network is described through a Markov chain. A token-dependent sliding mode control law is designed to dynamically adjust control parameters to accommodate SCP scheduling and PDT switching. A sliding mode function and a Lyapunov function are designed to ensure the accessibility of the sliding mode. The present invention effectively utilizes the advantages of a networked control method based on a continuous dwell time switching rule under random communication protocol scheduling, such as strong robustness, resource optimization, and reliable stability, effectively improving the operating efficiency of the inverted pendulum system.

The multi-vehicle-type random switching flexible total splicing system comprises a splicing platform and part feeding areas, and side walls on the two sides of the same vehicle type are stored in the part feeding areas on the two sides of the splicing platform correspondingly; the workpiece feeding area comprises a workpiece feeding rail and storage rails, the storage rails are located on the two sides of the workpiece feeding rail, a splicing sliding table and a welding robot sliding table are arranged on the workpiece feeding rail, a clamp, a movable tool table and a traction trolley are arranged on the storage rails, the traction trolley is connected with the movable tool table, and the clamp is fixed to the movable tool table and connected with a two-way pneumatic-electric switching assembly. And the clamp is kept in a clamping state when clamping the side wall. Compared with the prior art, the device has the advantages that the clamp is fixed to the movable tool table and connected with the two-way pneumatic-electric switching assembly, an air source and electric power are provided for the clamp, power and control signals are kept uninterrupted in the clamp transportation process, the clamp is kept in the clamping state, the position of the side wall is not changed, and the accuracy of the splicing position of the side wall is guaranteed.

The invention discloses an anti-electromagnetic interference method for an electronic device in an electric dragging system, which comprises the following steps of: 1, respectively analyzing conduction and radiation type interference in the electric dragging system; 2, a second-order RLC low-pass filter is adopted; 3, selecting a control strategy and an algorithm; fourthly, inductance, capacitance and resistance parameters of the conducted interference filter are calculated; 5, selecting a random switching frequency modulation strategy; and 6, designing a rotary transformer signal processing circuit and filtering an output position angle of a decoding chip of the rotary transformer. In combination with an electrical principle of a motor driving device, firstly, an interference filter is selected, then, algorithm selection operation is performed according to selection of a control strategy, and finally, anti-interference design of electronic devices related to resolver calculation is performed, so that conduction type electromagnetic interference at a power supply end is effectively inhibited, the switching frequency harmonic content is reduced, and the reliability of a resolver is improved. And the rotor position angle is accurately tracked.

The embodiment of the invention provides an online answer sheet method and a question generation method, and the online answer sheet method comprises the steps: responding to a selected target component, and determining a component type corresponding to the target component; under the condition that the component type is a random switching question, determining a selected timestamp of the target component; according to the selected timestamp, a target question group is determined from a target question pool, and the target question group is used for generating a target answer sheet; and displaying the target answer sheet on an answer interface. According to the technical scheme provided by the embodiment of the invention, the maintenance cost of the system or equipment can be effectively reduced, and the answer sheet generation efficiency can be improved.

The invention discloses a multi-band random switching frequency high-frequency harmonic suppression method for a permanent magnet motor, which comprises the following steps of: generating a random numbers by a linear congruence method, performing Chebyshev mapping, survival into b random numbers, forming a random number matrix with a rows and b columns, randomly extracting one number from each row, forming a group of random numbers, and generating random switching frequency; the spread spectrum range of the random switching frequency is set, the random switching frequency is divided into n sections, and the adjacent sections are partially overlapped; representing the upper and lower limits of each section of switching frequency by using the center frequency and the random number of the section, and writing an overlapping area expression of two adjacent sections according to the upper and lower limits of each section of switching frequency; the optimal solution of the harmonic dispersion coefficient is substituted into the overlapping area expression, the center frequency and the random number of each section are solved, the random switching frequency of the section is determined, and a pulse width modulation signal is obtained. The variable quantity of the adjacent switching frequencies is reduced while the occurrence probability of the center frequency is reduced, and high-frequency harmonics can be effectively suppressed.

The invention relates to the field of medical detection, and provides a sample priority switching method and device, equipment and a medium, which can query a to-be-switched sample, switch the priority of the to-be-switched sample according to the modification of a user to obtain a target sample when a signal that the user modifies the priority of the to-be-switched sample through a priority switching interface is received, and send the target sample to the user. The priority switching interface is used for assisting a user in modifying the priority of the to-be-switched sample so as to assist a detector in flexibly switching the priority of the sample according to the actual demand and issuing the target priority to a drive-by-wire, and switching information is recorded according to the target priority of the to-be-switched sample and the target priority of the to-be-switched sample. And the target samples are processed on the assembly line according to the target priorities through drive-by-wire, so that random switching of the sample priorities on the assembly line is realized, and the flexibility requirement of medical detection is met.

The invention provides a sensor network distributed filtering method and system based on adaptive event triggering under replay attack and topology switching, and relates to the technical field of signal processing. The invention aims to solve the problem that the estimation performance is reduced when the existing distributed filtering method has the problems of communication resource limitation, topology random switching, replay attack and the like in a sensor network. The method is characterized by comprising the following steps: establishing a state space model and a sensor output model of a discrete nonlinear time-varying stochastic system, and adopting a self-adaptive event triggering mechanism to enable the measurement of a distributed filter to be available; a replay attack compensation mechanism is established, and the influence caused by the replay attack on the sensor network is processed in time; the developed adaptive event-triggered distributed filter design algorithm is in a recursive form and is very suitable for online application. The method can effectively cope with multiple challenges such as bandwidth limitation, topology change and network security threats, has good applicability and practicability, and is more suitable for practical engineering application.

The invention provides a dual-random control method and system combining a dual-three-phase motor random switching sequence and a random carrier frequency. When a dual three-phase motor adopts space vector pulse width modulation, concentrated high-frequency harmonic waves exist at the switching frequency and the integral multiple of the switching frequency of phase current, and vibration noise is caused. The invention provides a double-random control method for a double-three-phase motor to suppress high-frequency harmonic waves, two different switch sequences are designed in each sector, and one switch sequence is selected through random numbers in each carrier period. And in the aspect of random carrier frequency, random number constrained variable delay control is provided, so that the carrier period is randomized, the high-frequency harmonic amplitude of the dual three-phase motor is finally reduced, and the vibration and noise of the motor are suppressed.

The invention discloses a two-path switching data weighted average circuit and an analog-to-digital converter, and belongs to the technical field of signal processing.The two-path switching data weighted average circuit comprises a first data selector, a second data selector, a first DWA sub-circuit and a second DWA sub-circuit, the input end of the first data selector is connected with a binary input signal, and the input end of the second data selector is connected with a binary output signal; the first output end and the second output end of the first data selector are respectively connected with the input end of the first DWA sub-circuit and the input end of the second DWA sub-circuit, and the output end of the first DWA sub-circuit and the output end of the second DWA sub-circuit are respectively connected with the first input end and the second input end of the second data selector. Based on the characteristic that an input signal has randomness, according to the fact that the lowest bit of the input signal is' 0 'or' 1 ', random switching is carried out in two paths of data weighted average circuits, and spurious generation is restrained.

1. The name of the design product: the main body of the expression input graphical user interface for electronic devices. 2. The use of the design product: an electronic device. 3. The design points of the design product: the part in the graphical user interface, the part outside the dotted line is the claimed part. 4. The picture or photo that best shows the design points: design 1 front view. 5. Design 1 is designated as the basic design. 6. The use of the graphical user interface: the overall interface is used for expression input and sending; the claimed part of the interface is used for expression assembly and switching. 7. The human-computer interaction mode of the graphical user interface: in design 1 front view, the user can click the "complete" control to enter the current expression combination into the input box, long press the rounded rectangle expression card control to expand the preview switching window of the corresponding expression library, click the "structure" control to switch the card structure, and click the "random" control to randomly switch the expression combination under the current card structure. The human-computer interaction modes of design 2 and design 3 are the same as those of design 1. In design 4 front view, the user can click the "complete" control to enter the current expression combination into an input box, long press the rounded rectangle expression card control to expand the preview switching window of the appropriate expression library, click the "structure" control to switch the card structure, click the "random" control to randomly switch the expression combination under the current card structure, and click the color disc control at the bottom of the interface to select the color combination to randomly generate the expression combination with the corresponding color. In design 5 front view, when the user clicks the "+ expression combination" control, it enters design 5 interface change state diagram 1; when the user clicks the "complete" control, it enters design 5 interface change state diagram 2. In design 6 front view, when the user clicks the "+ expression combination" control, it enters design 6 interface change state diagram 1; when the user clicks the "structure" control, it randomly switches the expression card structure and enters design 6 interface change state diagram 2. In design 7 front view, when the user clicks the "+ expression combination" control, it enters design 7 interface change state diagram 1; when the user clicks the "random" control, it randomly switches the expression combination and enters design 7 interface change state diagram 2. In design 8 front view, when the user clicks the "+ expression combination" control, it enters design 8 interface change state diagram 1; when the user long presses the leftmost expression card control, it enters design 8 interface change state diagram 2. In the design 9 main view, when the user clicks the "+ emotion combination" control, enter the design 9 interface change state diagram 1; when the user long-presses the middle expression card control, enter the design 9 interface change state diagram 2. In the design 10 main view, when the user clicks the expression combination control at the lower right of the "+ emotion combination" button twice, enter the design 10 interface change state diagram 1; when the user clicks the "send" control, enter the design 10 interface change state diagram 2.

The utility model discloses a pen capable of randomly switching and displaying patterns, which comprises a penholder, a refill, a first spring and a telescopic locking mechanism are respectively arranged in the penholder, a button is movably arranged at the rear end of the penholder, the first spring is arranged between the refill and the penholder, and the rear end of the refill is in linkage fit with the front end of the button through the telescopic locking mechanism. The pen holder is further connected with a pattern random switching display device, the pattern random switching display device comprises a shell, a rotating disc and a transmission piece, the shell is connected to the outer side of the pen holder and located on the side portion of the rear end of the pen holder, the rotating disc is rotatably arranged in the shell, a plurality of patterns are arranged at one axial end of the rotating disc, the shell is provided with a window, and the transmission piece is connected with a button. And the front end of the transmission part is in transmission fit with the turntable. The pen capable of randomly switching the display patterns is simple in structure, convenient to assemble and better in holding feeling.

The application relates to a high-frequency harmonic suppression method based on a motor control system, in particular to the technical field of motor control, and comprises the following steps: S1, calculating a modulation rate according to collected motor rotating speeds; S2, comparing the collected motor rotating speeds with preset motor rotating speeds n1, and taking different modes to suppress high-frequency harmonics according to comparison results; S3, when the motor rotating speed is less than n1, a random switching frequency method is used to suppress high-frequency harmonics in an asynchronous modulation mode; S4, when the motor rotating speed is greater than or equal to n1 and the modulation rate is less than a preset modulation rate k1, a random zero vector method is used to suppress high-frequency harmonics; and S5, when the motor rotating speed is greater than or equal to n1 and the modulation rate is greater than or equal to k1, an SVPWM method is used to suppress high-frequency harmonics. Different harmonic suppression modes are set according to different scenes, and the efficiency of suppressing harmonics is effectively improved.

The utility model provides an angle adjusting mechanism and a projector support, which belongs to the technical field of machinery and specifically comprises a fixed seat, a gear ring, a movable part, a fixed shaft, an elastic block assembly, an adjusting rod assembly, a gasket and a screw. According to the technical scheme, the adjusting rod with coaxial cylindrical sections of different diameters is adopted to be matched with the elastic block assembly and the gear ring, angle adjustment is achieved, random switching between a locking state and an unlocking state can be achieved, and the structure is simple.

The utility model relates to the technical field of card feeding devices, in particular to a card feeding device capable of switching double card boxes, which comprises a printing piece, a card feeding device shell is fixed at the front end of the printing piece, a push-in mechanism used for pushing in cards is arranged on one side of the card feeding device shell, and the printing piece is fixed on the printing piece. A clamping mechanism used for clamping cards is arranged in the card feeding device shell, and a switching mechanism used for switching the card boxes is arranged in the printing piece. And the switching mechanism comprises a first printing head, the first printing head is arranged at the lower end of the interior of the printing piece, a second printing head is installed above the first printing head, and connecting pieces are fixed to the right side of the second printing head and the right side of the first printing head correspondingly. Through the arranged switching mechanism, the upper surface and the lower surface of the card can be printed, then the effect of switching the double card boxes is achieved, random switching can be achieved in the printing process, the card does not need to be taken out and placed again, and the printing efficiency is improved.

The utility model discloses a folding type fruit and vegetable plastic box which comprises a fixed box body, the fixed box body comprises a bottom plate located at the bottom, two opposite first fixed side plates and two opposite second fixed side plates, the two first fixed side plates and the two second fixed side plates are fixedly connected to the upper surface of the bottom plate, a first movable plate is arranged between the two first fixed side plates, and a second movable plate is arranged between the two second fixed side plates. A second movable plate is arranged between the two second fixed side plates, and a first mounting clamping strip is arranged on the upper surface of the first fixed side plate; compared with the prior art, when the size of the fruit and vegetable plastic box needs to be reduced, storage of the first movable plate and the second movable plate is achieved, the interior of the fruit and vegetable plastic box is partitioned, when the size of the fruit and vegetable plastic box needs to be enlarged, overall capacity expansion of the fruit and vegetable plastic box can be achieved, the structure is simple, operation is convenient and fast, and practicability is high. Random switching can be achieved according to actual requirements, and the use flexibility of the fruit and vegetable plastic box is greatly improved.

The invention discloses an oversampling successive approximation type analog-to-digital converter for suppressing capacitor mismatch. The oversampling successive approximation type analog-to-digital converter comprises a sampling switch, a high-order equivalent capacitor array, a binary weighted capacitor bank, a C-2C step network, a comparator, a noise shaping module, a successive approximation control logic and a dynamic element matching circuit, wherein the successive approximation control logic module performs time domain modulation on the binary weighted capacitor bank and the C-2C ladder network, and harmonic waves caused by capacitor mismatch are shifted to a high frequency band; the dynamic element matching circuit performs pseudo-random switching control on the high-order equivalent capacitor array, and harmonic energy caused by element mismatch is averaged and then transferred to the noise floor of a frequency spectrum by using the rotation selection circuit. The noise shaping module forms a loop through a residual voltage feedback mechanism and pushes quantized noise away from a signal frequency band; on the premise that an additional calibration circuit is not introduced, the problem of performance deterioration caused by capacitor mismatch due to manufacturing process fluctuation of a traditional successive approximation type framework is effectively restrained, the overall precision and linearity of analog-to-digital conversion are remarkably improved, and the analog-to-digital conversion circuit is suitable for high-resolution application scenes.

The invention relates to an inverted pendulum system random communication protocol sliding mode control method based on continuous residence time, which belongs to the technical field of automatic control, and combines sliding mode control based on the inverted pendulum system based on the continuous residence time and sliding mode control based on a random communication protocol to construct a coordination controller; constructing a discrete time uncertain switching system model with a PDT switching rule, and describing a random switching behavior of a node access network through a Markov chain in combination with a random communication protocol scheduling mechanism; a token-dependent sliding mode control law is designed, control parameters are dynamically adjusted to adapt to SCP scheduling and PDT switching, a sliding mode function and a Lyapunov function are designed, and the accessibility of a sliding mode is ensured. The advantages of a networked control method based on a continuous residence time switching rule under random communication protocol scheduling are effectively utilized, the advantages of high robustness, resource optimization, stability and reliability and the like are achieved, and the operation efficiency of the inverted pendulum system is effectively improved.

The invention relates to the technical field of motor control, and particularly discloses a double-random PWM motor noise suppression method based on a Mersen rotation algorithm. Comprising the following steps that S01, double random modulation is established, the double random modulation comprises random pulse position modulation and random switching period modulation, the random pulse position modulation is used for conducting controllable random offset on the geometric center position of a carrier signal, and the random switching period modulation is used for conducting random offset on the geometric center position of the carrier signal; the random switching period modulation changes the frequency fs of the triangular carrier wave to realize randomization of the random switching period Tn of the system; and S02, generating a pulse position offset coefficient required by random pulse position modulation and a periodic random number required by random switching period modulation by adopting a Meisson rotation algorithm, and dispersing PWM harmonic energy to other frequency intervals so as to suppress a switching frequency sub-harmonic amplitude and a switching frequency sub-second harmonic amplitude.

The present invention relates to the technical field of sports training equipment, and specifically relates to a physical fitness training device based on an intelligent football goal. After the power is turned on and the switch is pressed, it enters the training mode. Twelve groups of induction plates randomly light up. If the ball hits the induction plate that is lit next time, points are scored; if it misses, other induction plates are randomly switched; a gravity sensor is installed on the back of the induction plate, with high sensitivity. By scoring, it can more intuitively record and evaluate the user's shooting skills. The user can understand the advantages and disadvantages of their own shooting angles through recording, and better carry out targeted training. At the same time, it is convenient to assemble and disassemble and is easy to use.

The application discloses a harmonic suppression method and device for silicon carbide semiconductors and a storage medium, belongs to the technical field of semiconductor design, and comprises the following steps: obtaining random numbers under a target number through a two-state Markov chain random number generator; performing asymmetric processing on the action time of a basic vector pair under the target logarithm through the random numbers in a random pulse position harmonic suppression method; performing adaptive improvement on a triangular carrier signal in a PWM waveform for the basic vector pair after the asymmetric processing; and performing modulation judgment on the opening and closing states of each silicon carbide semiconductor in a three-phase inverter bridge according to the improved triangular carrier signal, and obtaining a required asymmetric pulse signal. The asymmetric random pulse signal disperses high-frequency harmonics concentrated around the switching frequency and multiples to a greater extent, achieves the purposes of random zero vector step and random switching frequency, and reduces harmonics in a low-frequency operation state of a motor and EMI noise in a high-frequency operation state.