800results about How to "Prevent overshoot" patented technology

A voltage comparator of a power supply apparatus detects overshoot by comparing an output voltage with a threshold voltage. The power supply apparatus is provided with three switches. Upon detection of overshoot, the boosting operation of a booster circuit is suspended and the first through third switches are turned on. While the boosting operation is being suspended, the second switch operates to lower the output voltage. Concurrently, the first and third switches operate to forcibly lower an input voltage to allow the output voltage, occurring after the boosting operation is resumed, to approach a preset voltage.

The invention discloses a method for controlling an inverter compressor. According to the method, a target temperature and a dividing temperature point are preset, and a sensor monitors an actual temperature value. The method comprises the following steps that: a controller judges whether the difference between an actual temperature and the target temperature is zero, and the compressor operates at a minimum frequency for a certain period if the difference between an actual temperature and the target temperature is zero; the controller judges whether the target temperature is reached, and thecompressor stops operation if the target temperature is reached, or the controller initializes a PID parameter to allow an inverter to make the compressor start to raise frequency quickly if the target temperature is not reached; the controller judges whether the preset dividing temperature point is reached, and the PID parameter is adjusted if the preset dividing temperature point is reached, orthe PID parameter is kept constant if the reset dividing temperature point is not reached; and the controller judges whether the target temperature is reached, and the compressor operates at a constant frequency and the frequency inversion is finished if the target temperature is reached, or the compressor raises frequency while keeping the original PID parameter if the target temperature is not reached. Correspondingly, the invention also provides a device for controlling the inverter compressor. The method and the device can realize a quick, energy-saving and stable frequency inversion process at the same time.

The invention discloses a nonlinear self-adaption control method of near-space hypersonic vehicle (NHV), which belongs to a flight control method in the technical field of aerospace. The control method mainly comprises three control law parts: a nominal nonlinear generalized predictive control law (NGPC), a B-spline recursive functional linkage network (BRFLN) self-adaption control law, and a robust control law of gain self-adaption adjustment. The invention integrates the simplicity of the NGPC method and the effectiveness of dynamic uncertainty of the BRFLN learning, targets the immeasurable dynamic uncertainty and fast interference of an attitude system in the flight of the NHV, brings favorable learning effect, and realizes the nonlinear accurate control to the attitude angle.

Image sharpening is performed by applying variable contrast stretching to pixels of interest in a digital image. For each pixel of interest, the amount of contrast stretching is a function of minimum and maximum intensity values in a local pixel neighborhood.

The invention discloses a stepping motor control system and a control method thereof. The stepping motor control system comprises a controller, a stepping motor controller, a stepping motor, a transmission mechanism, a load and a photoelectric encoder, wherein the controller sends a plurality of pulses with a certain frequency and a certain quantity to the driver which receives the pulse information and a direction signal and acts on the stepping motor, the stepping motor drives the load through a driving mechanism, and the photoelectric encoder feeds back and transfers position information to the controller. The invention realizes high-accuracy positioning through a fuzzy control method, achievesprovides higher operation effect by adopting the combination of dual compensation feedback and open-loop control, has the desynchronizing detection function for compensatingrehending and feeding back failure information and also hasprovides higher failure suitability.

A voltage comparator of a power supply apparatus detects overshoot by comparing an output voltage with a threshold voltage. The power supply apparatus is provided with three switches. Upon detection of overshoot, the boosting operation of a booster circuit is suspended and the first through third switches are turned on. While the boosting operation is being suspended, the second switch operates to lower the output voltage. Concurrently, the first and third switches operate to forcibly lower an input voltage to allow the output voltage, occurring after the boosting operation is resumed, to approach a preset voltage.

A high-speed PWM control apparatus with adaptive voltage position and a driving signal generating method thereof is provided. The present invention automatically detects a change in the loading and adjusts the voltage position instantaneously for stabilizing the voltage and reducing the loading output power consumption. The present invention does not require a clock signal to generate a driving signal and does not require an error amplifier to control the modulation. Therefore, the present invention has a fast transient response that responds to the change of the loading instantaneously and has a stabilizing effect. When the apparatus is on a continuous conduction mode (CCM), the switching frequency of the controller is still fixed even though the input voltage Vin and the output voltage Vout are changed. The electrical-magnetic noise disturbance is improved.

The invention provides a permanent magnet synchronous motor servo driving device and a position control method thereof. The permanent magnet synchronous motor servo driving device mainly comprises a controller, a power inverter, a current sensor, a position sensor and a permanent magnet synchronous motor. Besides the adoption of the controller structure, correction information of velocity feedback is also used for effectively reducing position following deviation. The position control method for the permanent magnet synchronous motor servo driving device compensates disturbance by designing and using torque observation of velocity model deviation. The implementation is simple, the torque observation result is not affected by velocity change, the quickness of position follow is improved, and the disturbance adaptability of a load is improved.

The invention relates to a thermal power generating unit reheated steam temperature controlling method. According to the operating characteristics of the boiler reheater and the theoretic study on a steam-temperature control system, a state feedback control method based on incremental state observer is adopted, and the concept of an algebraically equivalence observer is used to direct the parameter setting of an incremental state observer; in addition, a special control circuit is arranged in the steam-temperature control circuit to resolve the problems that the process of steam-temperature adjustment is relatively long when the reheated steam temperature set value is changed, non-linearity exists during steam-temperature control, the process of steam-temperature variation is very slow, etc., and variation parameter PID regulator is combined to jointly form a comprehensive reheated temperature automatic adjusting system. The invention is capable to ensure reheated steam temperature control to escape spray water upon large-range load variation, and effectively overcomes the disadvantage of the poor effect of the traditional PID regulation on the control of big lagged object; the reheated temperature control effect is improved remarkably; and a sample is provided for controlling the controlled object with big inertia and serious lagging in relation to reheated steam temperature.

The invention provides an automatic aperture adjusting device and method based on self-adaptive adjustment. The automatic aperture adjusting device comprises an automatic aperture lens, an average brightness calculation unit, an automatic aperture control unit and an automatic aperture motor, wherein the automatic aperture lens is used for collecting images; the average brightness calculation unit is used for calculating the average brightness of an image acquired by the automatic aperture lens; the automatic aperture control unit is used for generating a control signal which controls the size of the aperture according to the difference of the average brightness calculated by the average brightness calculation unit and target brightness; and the automatic aperture motor is used for controlling the size of the aperture of the automatic aperture lens according to the control signal outputted by the automatic aperture control unit. The size of the aperture can be adaptively controlled byanalyzing the current state of the aperture, so that the device can be applied to various automatic aperture lenses, and avoids the problems such as manually adjusting parameters and the like.

The invention provides a composite control method for piezoelectric ceramic positioning. In the method, different control combination ways are adopted in an entire process; a threshold value delta is set; composite control of feedback control and PID (Proportion Integration Differentiation) control, or composite control of feedback control and PD (Proportion Differentiation) control is used selectively according to the magnitude relation between a displacement deviation e (kT) and the threshold value delta. According to the method, a mathematical model is required to be established, the lag and nonlinearity of a piezoelectric ceramic driver are described by adopting the conventional Preisach model, and the parameter of PID or PD is self-tuned on line by using fuzzy control, so that optimal control of a system can be realized, and the system has the advantages of flexibility, high adaptability and the like of fuzzy control. In the method, a selective control method combination is used for the first time, so that the positioning accuracy of piezoelectric ceramic is increased effectively, the stability and interference resistance are enhanced, the response rise time is shortened, and lag and creepage are eliminated effectively simultaneously.

A device for limiting the temperature of cookware on a cooktop to a threshold level that corresponds to an oil ignition temperature. The device includes a temperature sensor that is positioned adjacent a bottom of the cookware on the cooktop. A control device in combination with each of the temperature sensor and the cooktop monitors the temperature and adjusts a heating element of the cooktop as needed to avoid cooking oil ignition. The temperature sensor can be a spring loaded temperature sensor to ensure and / or absorb contact with the cookware.

A shipborne camera shooting stabilized platform control method with an active disturbance rejection control technology adopted includes the following steps that (1) a discrete time state-space model of a shipborne camera shooting stabilized platform control system is built; (2) a tracking differentiator is designed, and the rotation angle of a camera shooting stabilized platform can track the reference angle as soon as possible without overshoot; (3) an extended state observer is designed to estimate the rotation angle, the rotation angular speed, the rotation angular acceleration and the total disturbance of the camera shooting stabilized platform; (4) tracking errors of the angle, the angular speed and the angular acceleration are obtained according to the output of the tracking differentiator and the output of the extended state observer, and then a nonlinear control rule and a disturbance compensation strategy are designed according to the error information. By means of the shipborne camera shooting stabilized platform control method, the tracking accuracy and rapidity of the camera shooting stabilized platform are guaranteed, and the high disturbance rejection capacity is provided.

The invention relates to a piezoelectric switch type valve positioner control method and a piezoelectric switch type valve positioner control system. The system consists of a 4-20mA current source, a current-to-voltage (I / V) conversion circuit, a voltage conversion module, a control signal amplifying and filtering circuit, a feedback signal amplifying and filtering circuit, 2 external analog-to-digital converter (ADC), an ultra-low power consumption singlechip, a liquid crystal keyboard module, an electrically erasable programmable read-only memory (EEPROM), a passive crystal, and a piezoelectric valve driven amplifying circuit. The control method comprises the steps of: determining the optimum pulse width modulation (PWM) duty cycle during the self-tuning of parameters; and adopting a five-step switching method with reverse PWM during the control. The piezoelectric switch type valve positioner control method and the piezoelectric switch type valve positioner control system can effectively avoid the overshoot phenomenon during the control of a valve positioner, solve the non-linear problem of an actuating mechanism, and have stronger universal applicability.

An automatic transmission ratio shift control system and method for a powertrain having an engine and multiple-ratio gearing controlled by friction elements actuated by hydraulic pressure, an electronic controller for establishing torque transitions among the friction elements as the gear ratio changes, the engine speed being controlled by an electronic throttle control. The strategy employs an electronic throttle and closed loop engine speed control and uses fuel and air as an energy source to increase engine speed during a power-off downshift. The engine speed is boosted to a level close to the synchronous speed in conjunction with release of the off-going friction element. The on-coming friction element is then applied as the engine speed approaches a desired speed. The engine speed increase is timed to lead an increase in torque converter speed.

The invention discloses a photovoltaic energy storage refrigerator car hybrid refrigeration system and a switching method thereof under different working conditions. The photovoltaic energy storage refrigerator car hybrid refrigeration system comprises a refrigeration system body composed of an electric compressor, a mechanical compressor, an expansion valve, a condenser and an evaporator. The power source of the mechanical compressor is an engine. The power source of the electric compressor is a photovoltaic power supply system. The photovoltaic power supply system comprises a photovoltaic panel, a photovoltaic controller, a super capacitor, an inverter and a storage battery. The photovoltaic controller has an effect of controlling the super capacitor and the storage battery to reasonably charge and discharge, the service life of the storage battery is beneficially prolonged, and the discharging efficiency is improved. According to the photovoltaic energy storage refrigerator car hybrid refrigeration system and the switching method thereof under the different working conditions, the mode of double compressors is adopted, thus, the engine can be used to provide the refrigeration power source during refrigerator car transportation, a solar power generating system can be used to supply power for refrigerating during resting halfway, at night and when a carriage needs to be precooled, the problem that an external power source is needed when a refrigerator car is stopped is solved, and the delivery range is greatly expanded.

The invention discloses an ultrasonic intelligent bird scarer which is characterized in that the bird scarer comprises a power module (2), a radar signal detection module (3), an ultrasonic bird scaring module (4) and a microprocessor control module (1); the power module, the radar signal detection module, the ultrasonic bird scaring module and the microprocessor control module are all connected with the microprocessor control module; the microprocessor control module is formed by a single chip microprocessor; the power module consists of a solar cell and a 12V storage cell; the radar signal detection module comprises a plurality of doppler radars; and the ultrasonic bird scaring module consists of more than two ultrasonic high frequency horns.

Each boosting cell includes: a first n-transistor having a diode connection; a second n-transistor whose gate and drain are connected to a power supply voltage and whose source is connected to the source of the first n-transistor; and a boosting capacitor provided between the drain of the first n-transistor and a boosting clock input terminal to which a clock signal is input. The boosting capacitor is connected to n auxiliary boosting capacitors in parallel via connection switching circuits controlled with boosting ability switching signals as control signals input from the outside.

The invention discloses a direct-current pre-excitation starting method for the VVVF (Variable Voltage Variable Frequency) control of an asynchronous motor under flux linkage control, belonging to the technical field of the starting control of asynchronous motors. The direct-current pre-excitation starting method for the VVVF control of the asynchronous motor under the flux linkage control is characterized in that an included angle for synthesizing an excitation current vector and a starting voltage vector in a starting process is 90 degrees; a current is decomposed according to a known voltage vector direction for the VVVF control to obtain a reactive current feedback value; and the reactive current feedback value is converted into a voltage regulation value by gain amplification to control the flux linkage. In the invention, the direct-current pre-excitation and the starting process are controlled sequentially by using a DSP (Digital Signal Processor) chip. The method has an inhibition effect on the peak current subsequently appearing in the starting process.

A device for limiting the temperature of cookware on a cooktop to a threshold level that corresponds to an oil ignition temperature. The device includes a temperature sensor that is positioned adjacent a bottom of the cookware on the cooktop. A control device in combination with each of the temperature sensor and the cooktop monitors the temperature and adjusts a heating element of the cooktop as needed to avoid cooking oil ignition. The temperature sensor can be a spring loaded temperature sensor to ensure and / or absorb contact with the cookware.

The present invention relates to a receiver apparatus, analog-to-digital converter apparatus, and method of converting an analog input signal into a digital output signal, wherein an additional direct feedforward path is introduced to compensate for peaking of feedforward structures while preserving frequency selectivity of the feedforward topology. In particular, the direct feedforward path (72) is provided with a scaling by a direct feedforward coefficient (ao) greater than zero and less than one. As a result, overshoot or peaking of classical feedforward topologies can be suppressed while providing interferer immunity, anti-aliazing effects and loop stability.

A supercharger control device for an internal combustion engine is preferably applied to a system having a first supercharger and a second supercharger. A switching supercharging pressure setting unit sets a switching supercharging pressure used in case of switching a mode for operating the first supercharger and the second supercharger, based on a difference between a target supercharging pressure and an actual supercharging pressure. When the actual supercharging pressure reaches the switching supercharging pressure, a switching control unit performs a control of switching the mode. Therefore, it becomes possible to appropriately prevent the overshoot of the supercharging pressure at the time of switching the mode.

A motor control method with high dynamic response speed and high control precision features that the current loop control instead of speed loop control is used, in which the optimized PI control method is used, the depth of throttle is directly relative to the current iq for dynamically detecting the current value, and the difference between the target current and actual current is used as the input of current loop.

The invention discloses a self-powered vehicle vibration damping device which comprises a vibration damping device body and a vibration damping device controller, wherein the vibration damping device body comprises a first cylinder body, a piston rod, a piezoelectric generating unit, a transmission force spring unit, a magneto-rheological damping unit and an electromagnetic induction unit; the piezoelectric generating unit comprises a plurality of piezoelectric modules, and a plurality of piezoelectric vibrators are inlaid in each piezoelectric module; the transmission force spring unit comprises an upper spring pressing plate, a lower spring pressing plate, a lower spring clamping seat, an upper spring clamping seat and a transmission force spring; the magneto-rheological damping unit comprises an outer cylinder, an inner cylinder, a permanent magnet protecting cover, an upper damp channel, a lower damp channel, a magnet exciting coil and a piston; and the electromagnetic induction unit comprises a leakage-proof magnetic sleeve, a second cylinder body, a permanent magnet and an electromagnetic induction coil. The invention further discloses a control method for the self-powered vehicle vibration damping device. The self-powered vehicle vibration damping device provided by the invention is high in energy-regenerative efficiency, good in work stability, high in reliability, can adjust the damping force in real time, and ensures that a vehicle is in an optimal vibration damping state.

Provided is a four-rotor aircraft output-limited backstepping control method based on an integral sliding mode obstacle Lyapunov function. For the dynamic system of a four-rotor aircraft, an integralsliding mode obstacle Lyapunov function is selected, and a four-rotor aircraft output-limited backstepping control method based on the integral sliding mode obstacle Lyapunov function is designed. Theintegral sliding mode obstacle Lyapunov function is designed in order to ensure that the output of the system is limited within a certain range, avoid too large overshoot and reduce the time of arrival. Therefore, the dynamic response performance of the four-rotor aircraft system is improved. The invention provides a four-rotor aircraft output-limited backstepping control method based on an integral sliding mode obstacle Lyapunov function, which enables the system to have a good dynamic response process.

The invention provides a digital optimization control method and system for synchronous rectification of an LLC full bridge converter. The drain terminal voltage before and after the shut-off of a synchronous rectification tube at the full bridge LLC secondary side is respectively sampled; the twice sampling results are subjected to logic comparison through a comparator; a microcontroller regulates the shot-off time of the synchronous rectification tube at the full bridge LLC secondary side according to the logic comparison result; the precise sampling of the drain terminal voltage before and after the shut-off of the synchronous rectification tube at the full bridge LLC secondary side is realized by using the interruption matching of the microcontroller; the shut-off of the synchronous rectification tube at the full bridge LLC secondary side at the optimum shot-off time is realized through comparing the time command to be regulated given by the microcontroller in real time; and the whole efficiency of the full bridge LLC is improved.

The present invention provides a PD-type compact-format model-free adaptive navigational speed control method for an ocean vehicle. The method comprises the steps of: issuing an expected navigationalspeed instruction to an ocean vehicle, namely y*(k); employing a compass to measure a current actual navigational speed of a ship, and calculating a navigational speed error absolute value as input ofa PD-type CFDL_MFAC controller; solving the expected instruction by the controller, receiving and executing the expected instruction by an ocean vehicle feed mechanism to change the navigational speed of the ocean vehicle; and measuring the navigational speed of the ocean vehicle at the next moment through the compass carried on the ocean vehicle, performing difference of the navigational speed and an expected navigational speed, obtaining an absolute value, and taking the absolute value as input of the CFDL_MFAC controller at the next moment. The PD-type compact-format model-free adaptive navigational speed control method for the ocean vehicle considers the influence of environmental disturbance on the navigational speed of the ocean vehicle, and repeatedly performs the process mentionedabove until the actual navigational speed of the ocean vehicle is subjected to stable convergence to the expected navigational speed. The PD-type compact-format model-free adaptive navigational speedcontrol method for the ocean vehicle have a prediction effect on dynamic evolution of the navigational speed of the ocean vehicle so as to reduce the overshoot of the navigational speed control system and perform steady-state regulation of time consuming.

The invention discloses a motion control method for the autonomous berthing of an unmanned surface vessel and belongs to the unmanned surface vessel autonomous berthing motion control field. The method includes the following steps that: a current control system mode is determined according to the current berthing state of the unmanned surface vessel; the current actual speed or heading of the unmanned surface vessel is obtained, and the control deviation and deviation change rate of the heading or speed are obtained; with the control deviation and deviation change rate of the heading or the speed adopted as the input of a fuzzy controller, an appropriate control parameter variation quantity is selected on the basis of the current control system mode, and a control parameter is updated; andwith e(t) adopted as the input of the controller, and the controller outputs a desired control command to an actuator. According to the motion control method of the invention, improvement is made onthe basis of the traditional PID controller, and the controller has two modes, namely, a remote end mode and a nearshore mode; an adaptive fuzzy control rule is added, so that the controller can dynamically and adaptively adjust the control parameter according to berthing behavior change; and therefore, a motion control problem under the influence of weak maneuverability, large disturbance and a strong bank effect during the autonomous berthing of an under-driven unmanned surface vessel can be solved.

An actual detected current value and a target voltage value of an electric motor are subjected to a low-pass filter process, and amounts of change per time in the filtered actual current value and the filtered target voltage value are calculated. If the amount of change in the actual current value on the increase side is greater than a criterion value and the amount of change in the target voltage value on the decrease side is greater than a criterion value, it is judged that the stroke end has been reached. Then, the upper limit value of the target current value is set at the actual current value obtained in the immediately previous cycle of the feedback control, so as to prevent generation of unnecessary torque.