481results about How to "Reduce overshoot" patented technology

Systems and methods for haptic feedback effects for control knobs are described. One method comprises the steps of receiving a sensor signal associated with a motion of a manipulandum in a degree of freedom, and determining a direction of the motion of the manipulandum in the degree of freedom based on the sensor signal. The method further comprises outputting a first force signal if the determination indicates that the manipulandum moves in a first direction in the degree of freedom, and outputting a second force signal if the determination indicates that the manipulandum moves in a second direction in the degree of freedom.

A circuit and method for controlling a spread spectrum transition are presented comprising a first circuit and a second circuit. The first circuit may be configured to generate a clock signal in response to (i) a reference signal, (ii) a sequence of spread spectrum ROM codes, and (iii) a command signal. The second circuit may be configured to synchronize the command signal to a feedback signal. The sequence of spread spectrum ROM codes may be generated according to a predetermined mathematical formula and optimized in accordance with predetermined criteria.

The invention discloses a switch converter, a control circuit of the switch converter, and a control method of the switch converter. By conditioning ramp compensation signals according to the load condition, the overshoot degree of the output voltage of the switch converter is reduced during the instantaneous descending of load current while stable operation of the switch converter is maintained, and the transient response of the switch converter is improved.

A method for referencing a polyphase stepper motor by monitoring the current step response in at least one driven phase is presented. The coil current step response is compared to past step responses in order to determine when an increase in or maximum load is present. A combination of step to step variance, step response variance from mean current magnitude, and average current magnitude variance, as well as other measures can be combined to create an algorithm output. The output is compared to a pre-determined threshold and if the value is greater than the threshold, the motor is commanded to halt its position, which remains magnetically synchronous. This position is then used as a reference point to zero, or to home the motor.

The present invention provides haptic sensations for a haptic feedback device and especially for a rotational device such as a knob. Force effects such as a hill force effect and barrier force effect allow easier selection of menu items, menus, values, or other options by the user. Force models are also described to allow greater selection functionality, such as a scrolling list with detents and rate control borders, a jog shuttle, a push-turn model, a double-push model, and a cast control model.

The invention provides a self-disturbance control method for a permanent magnet synchronous motor, and belongs to the technical field of permanent magnet synchronous motor control. The method comprises the steps of: designing a hyperbolic tangent function expansion state observer, adopting the saturation characteristics itself of the hyperbolic tangent function to effectively suppress a differential peak appearing in a traditional expansion state observer so as to improve the system control performance. The non-linear feedback control rate based on the new adaptive sliding mode control is proposed which is characterized by designing a new adaptive shifting index approach law which introduces a first-order norm of the state variable, and an approaching speed is adaptively regulated according to the distance of the state variable from the balance point to reduce the dependence of the self-disturbance control on the parameter robustness so as to achieve the high-precision and high robustness control of a permanent magnet synchronous motor. When the system is disturbed and a load fluctuates, the rotation speed is rapidly tracked, the response speed of the system is improved, the systemovershoot and the steady state static difference are reduced, and the system robustness is greatly enhanced.

An audio peak limiter in which the lower sideband of the modulation distortion spectrum is canceled. The peak limiter is realized by multiplying the input signal by a control signal. The Hilbert transform of the control signal is multiplied by the Hilbert transform of the input signal and the outputs of the two multipliers are added. This cancels the lower sideband of the modulation process. Various filters can be added to eliminate aliasing in digital realizations, to band-limit the output signal, and to control peak overshoot.

The invention relates to a low dropout linear voltage regulator (LDO) without an off-chip capacitor for improving transient response and increasing power supply rejection ratio (PSRR). The LDO without the off-chip capacitor comprises an error amplifier, a reference voltage source module, a power adjusting tube, an NMC Miller's compensating circuit, a PSRR enhanced network and a transient response intensifier circuit. According to the LDO without the off-chip capacitor, the NMC compensation technique is used for meeting the system stability requirement; a second-stage gm improved circuit of the amplifier is used for increasing the charging and discharging currents to the grid of the power tube; a slew rate intensifier circuit is introduced, needed currents can be provided for a load when the load of the LDO is subjected to step hopping from small to large, and thus the transient response capacity of the LDO is improved under the double actions. In addition, the PSRR enhanced network is additionally arranged to be used for controlling the PSRR feedback factors beta of the system, an original zero point is pushed to the position with higher frequency, and therefore the PSRR characteristic of the system is improved. The LDO without the off-chip capacitor is improved on the aspect of transient response and the aspect of PSRR.

The invention relates to a two-position three-way inverse proportion decompression electromagnetic valve for an AT (Automatic Transmission). The two-position three-way inverse proportion decompression electromagnetic valve is mainly formed by a main valve and a proportion electromagnet, wherein the main valve is formed by a valve body, a valve core which is positioned at the inner part of the valve body, a valve seat which is sleeved on the valve body and an inner valve core which is positioned at the inner part of the valve core and close to one side of the valve seat, and the proportion electromagnet is formed by a sliding bearing, a bearing seat, a pole shoe, an armature, a top rod, a stroke gasket, a stop iron, a spring seat, a regulating spring, a baffle plate, a regulating screw, a baffle plate cushion, a coil and a yoke iron. According to the two-position three-way inverse proportion decompression electromagnetic valve disclosed by the invention, the problems such as lower response speed, larger pressure fluctuation, short service life, large leakage rate and high manufacturing cost of an existing inverse proportion decompression electromagnetic valve for the AT are solved, and the two-position three-way inverse proportion decompression electromagnetic valve disclosed by the invention has the advantages of high response speed, small pressure fluctuation, long service life , small leakage rate, lower manufacturing cost and the like.

The invention discloses a gallium-nitride-based light emitting diode capable of improving electron injection efficiency. The gallium-nitride-based light emitting diode comprises a substrate, a gallium nitride nucleation layer, a buffer layer, an n-type contact layer, a lower multicycle n-type electron coupling layer, a lower tunneling potential barrier layer, an upper multicycle n-type electron coupling layer, an upper tunneling potential barrier layer, a multicycle active luminous layer, a negative electrode, a p-type electron blocking layer, a p-type contact layer and a positive electrode, wherein the gallium nitride nucleation layer is manufactured on the substrate; the buffer layer is manufactured on the gallium nitride nucleation layer; the n-type contact layer is manufactured on the buffer layer; a table top is formed on one side of the upper surface of the n-type contact layer; the lower multicycle n-type electron coupling layer is manufactured on the other side of the table top on the n-type contact layer; the lower tunneling potential barrier layer is manufactured on the lower multicycle n-type electron coupling layer; the upper multicycle n-type electron coupling layer is manufactured on the lower tunneling potential barrier layer; the upper tunneling potential barrier layer is manufactured on the upper multicycle n-type electron coupling layer; the multicycle active luminous layer is manufactured on the upper tunneling potential barrier layer; the negative electrode is manufactured on the table top of the n-type contact layer; the p-type electron blocking layer is manufactured on the multicycle active luminous layer; the p-type contact layer is manufactured on the p-type electron blocking layer; and the positive electrode is manufactured on the p-type contact layer to form the structure of the gallium-nitride-based light emitting diode.

PID control performs integral control using an integral value of a deviation between a set temperature and current temperature. In particular, when a proportionality factor Kp is large, a fixing belt reaches a target temperature quickly but overshoot increases. On the other hand, when the proportionality factor Kp is small, the output is reduced gradually, and therefore the fixing belt reaches a target temperature slowly but the overshoot is small. Thus, a heat value control section changes the control value of the PID control according to the temperature (belt temperature) of a fixing belt at the start of heating as detected by a temperature detector. More specifically, a proportionality factor Kp of a calculation expression of the PID calculation is changed according to the belt temperature of the fixing belt. This makes it possible to reduce an overshoot when the temperature of the fixing belt increases.

Charge pump circuit. A charge pump circuit is provided for use in a phase-lock loop circuit. The charge pump circuit comprises a charge pump core circuit that outputs a control voltage. The charge pump circuit also comprises a replica circuit that is coupled to the charge pump core circuit, wherein the replica circuit receives the control voltage and produces one or more bias signals that are coupled to the charge pump core circuit to minimize the difference between charge up and charge down currents generated by the charge pump core circuit.

A wireless user terminal (42) and system (40) implementing a mixed signal CODEC (100) including an improved sigma-delta ADC (18) which limits input signals into a switched capacitor configuration and avoids adding circuit overhead in the signal path is disclosed herein. This sigma-delta analog-to-digital converter (18), having an input signal and an output signal, includes a switch (sw1), a clipping circuit (20), and a known sigma-delta ADC (34). It solves the clipping signal problem by limiting the signal right at the input of the sigma-delta ADC (34). The clipping circuit (20) couples to the switch (sw1) and the sigma-delta ADC (34) for switching the voltage applied to the sigma-delta ADC between the input signal (vin) and at least one threshold voltage (Vn and Vp).

A voltage generating circuit that drives multiple output terminals in alternating positive and negative cycles has two resistor ladders, one resistor ladder generating voltages for the positive cycles, the other resistor ladder generating voltages for the negative cycles. Single-ended amplifiers are connected directly to the resistor ladders, and a switching circuit connects each output terminal to a selectable one of the amplifiers. The output terminals may be precharged to opposite potentials at the beginning of positive and negative cycles, and the resistor ladders may include switching elements that initially set all generated voltages to these potentials so that the amplifiers start each cycle with equal input and output levels, reducing overshoot and undershoot. This voltage generating circuit saves space and power in driving, for example, a display panel in a mobile telephone.

An active hybrid circuit for a full duplex channel generates a duplicated voltage at the current output stage to reduce the energy of the transmitter transmitted to the receiver. The active hybrid circuit cancels the energy of the transmitter transmitted to the receiver when it is operated in a full duplex channel with high-speed transmission. The active hybrid circuit for full a duplex channel comprises a transmit digital-to-analog converter for generating an analog transmit signal, a receive analog-to-digital converter for receiving an analog receive signal, a duplicated voltage digital-to-analog converter for generating a corresponding duplicated voltage according to the analog transmit signal of the transmit digital-to-analog converter, and a plurality of signal combiners for subtracting the duplicated voltage from the analog transmit signal to cancel the influence of analog transmit signal to the analog receive signal.

A flight control system for an aircraft receives a selected value of a first parameter, which is either the airspeed or inertial velocity of the aircraft. A primary feedback loop generates a primary error signal that is proportional to the difference between the selected value and a measured value of the first parameter. A secondary feedback loop generates a secondary error signal that is proportional to the difference between the selected value of the first parameter and a measured value of a second flight parameter, which is the other of the airspeed and inertial velocity. The primary and secondary error signals are summed to produce a velocity error signal, and the velocity error signal and an integrated value of the primary error signal are summed to produce an actuator command signal. The actuator command signal is then used for operating aircraft devices to control the first parameter to minimize the primary error signal.

This invention relates to a correctional method of water level in the steam drum based on the temperature and pressure that belongs to the heat process control field including the following steps: the temperature difference DeltaT is linear to the water supply flow increment in small range, DeltaQ=-kDeltaT, theDeltaQ is used as the feedforward value in the main circuit of the cascade control of the water level in the steam drum, to eliminate the adverse effect of 'false water level' on the water supply control. When the load increases,DeltaQ>0, and the steam drum working condition is nearly stable, the correctional value is 0; when the load decreases, the controlled water supply is suppressed, DeltaQ<0; when the water flow increases, the temperature T of the steam drum decreases and the water supply flow increment DeltaQ<0; when the water supply flow is nearly constant, the correctional value is 0; when the water supply flow decreases, the controlled supply flow increases, DeltaQ>0. This method introduces the effect of steam drum pressure and water temperature on the steam bubble in the steam drum water to correct the water level control, which suppresses the overshoot phenomenon and ensures the steady operation of the boiler.

The invention relates to a large-scale open channel water level automatic control method based on storage capacity dynamic regulation. The method comprises the steps of determining a feed-forward flow regulating value; determining whether the feed-forward flow regulating value needs to be subjected to feedback correction or not; calculating a feedback correction value of a feed-forward control flow; calculating a flow regulation target value; calculating the actual opening of a gate; adjusting the opening of the gate. The method disclosed by the invention adopts a feed-forward flow control mode and fully considers the influences of division flow and water level dead areas for controlling a water surface profile of the whole channel section, so that water level fluctuation at local points can be flattened and filtered out, the sensitivity to movement dead areas of the gate is reduced, and accordingly frequent operation for the gate is reduced. Storage capacity compensation conditions required by stable water delivery are conveniently realized, so that the phenomenon of water level overswing is effectively reduced, and stability can be more quickly realized. The control principle is simple and clear and easy to realize and grasp, the influences of various disturbance factors can be effectively avoided, the operation and management cost of an open channel is reduced, the water delivery safety is ensured, and the water delivery efficiency is improved.

The invention provides a three-phase voltage type rectifier and a control method thereof. Through providing the high-robustness three-phase voltage type rectifier, a better inhibition effect on both overshooting and steady state error of a system is achieved while the high utilization rate of the voltage of an electric grid is guaranteed. The three-phase voltage type rectifier and the control method thereof have the following advantages: 1, the utilization rate of the electric grid can be increased by 15.4% through adopting an SVPWM (Space Vector Pulse Width Modulation) method compared with that achieved by an ordinary PWM (Pulse Width Modulation) method; 2, a voltage loop adopts a sliding-mode variable structure control (VSC) algorithm to replace the traditional PID (Proportion Integration Differentiation) control algorithm, thus the three-phase voltage type rectifier can rapidly respond to the voltage change of a direct current side; and 3, the voltage loop adopts a PID and VSC combined control method to replace the traditional PID control algorithm, so that the three-phase voltage type rectifier can rapidly respond to current change and can output stable control signals, and then, the overshooting and steady state error of the direct current side are reduced.

The invention discloses a medical perfusion type irrigator, belonging to the technical field of medical equipment. The medical perfusion type irrigator comprises a microprocessor module and a peristaltic pump, wherein the microprocessor module sends signals to the peristaltic pump to control the liquid outlet pressure and liquid outlet flow speed of the peristaltic pump; the microprocessor module is connected with a keyboard module, a pressure sensor, a flow speed sensor and a display module. The medical perfusion type irrigator disclosed by the invention can provide irrigation fluids with two flow speeds and four pressures, and can accurately control the temperature of the irrigation fluids and realize continuous irrigation as well as intermittent irrigation; with human-machine interaction, the irrigator is friendly and convenient to operate; moreover, in a special situation, the irrigator can give an alarm through sound and light to remind the medical personnel to handle exception in time. The medical perfusion type irrigator disclosed by the invention is applicable to multiple operations and the irrigation of multiple operative sites or tissues.

The invention discloses a control method for preventing excessive adjustment of coal feed for a boiler in the process of varying load, which is characterized in that a set value of main stem pressure obtained via a sliding pressure function is subjected to inertial filtering by four variable parameter inertial procedures, the change of the set value of the main steam pressure within a varying load starting period of a unit is delayed, the deviation between the set value of the main steam pressure and actual steam pressure within the starting period is reduced, and accordingly the excessive adjustment of coal feed for the boiler in the process of varying load is lessened, and influence of main steam pressure fluctuation on stability of the whole unit is prevented. By the control method, operational stability of the unit can be improved effectively.

The invention discloses a method, transport layer protocol entity, device and system of transmitting data in a communications network. The method comprises opening and configuring a port of a transport layer protocol and determining a context profile for the port. The transport layer protocol entity sends data packets e.g. to the Internet Protocol layer according to the context profile.

The invention discloses an anti-saturation PID (Proportion Integration Differentiation) control method for a motor speed regulation system. An integral predictor is added into a common PID controller; when an executor is saturated, the integral state predictor utilizes an error e of a control command value and a system output value, a differential value of the error and a limiter output value together to calculate a stable-state integral state value; and after the stable-state integral state value is processed by a low pass filter, integral items are reset. The method can be used for effectively inhibiting the integral saturation phenomenon, so that the controller can obtain smaller overshooting and shorter desaturation time in the case of saturation. The anti-saturation PID control method can be applied to the PID controllers of various motor speed regulation systems.

The invention discloses a current switching circuit for a high-speed current rudder digital-to-analog converter, comprising a switch main body circuit, a constant-current circuit which provides a constant flow source for the switch main body switch, a switch drive circuit which provides difference switching signals to the switch main body circuit and a four-phase control signal generating circuit which provides difference control signals for the switch drive circuit. A pre-breakover pull-down MOS (Metal Oxide Semiconductor) tube is adopted in the switch drive circuit , and a clock feedthrough compensation structure is applied to the switch main body circuit, thus overshooting of the difference switching signals is greatly weakened, falling edges of the difference switching signals at the initial stage of hopping become gentle, symmetry of rising and falling edges of the difference switching signals in case of low swing amplitude is improved and clock feedthrough errors resulting from the difference switching signals are effectively reduced. The current switching circuit is especially applicable to the high-speed and high-precision digital-to-analog converter.

A method for referencing a polyphase stepper motor by monitoring the current step response in at least one driven phase is presented. The coil current step response is compared to past step responses in order to determine when an increase in or maximum load is present. A combination of step to step variance, step response variance from mean current magnitude, and average current magnitude variance, as well as other measures can be combined to create an algorithm output. The output is compared to a pre-determined threshold and if the value is greater than the threshold, the motor is commanded to halt its position, which remains magnetically synchronous. This position is then used as a reference point to zero, or to home the motor.

The present invention discloses a low voltage drop linear voltage regulator comprising a switch element, an operational amplifier and an overshoot suppression circuit. The switch element possesses a source, a drain and a grid, the source is coupled with an input voltage, and the drain is used to output an output voltage. The operational amplifier possesses a first input end, a second input end and an output end, the output end is coupled with the grid of the switch element, and the first and second input ends are coupled with a reference voltage and a feedback voltage respectively. The overshoot suppression circuit is coupled among the input voltage, the switch element and the operational amplifier. At the transient state period of starting the input voltage, the overshoot suppression circuit outputs a suppression voltage to the switch element, so that the switch element is cut off. When the input voltage reaches an operation steady state period, the overshoot suppression circuit cuts off, and the operational amplifier control the conduction or cut-off of the switch element.

The invention relates to a permanent magnet synchronous motor current increment prediction algorithm which comprises the following steps: (1) a stator d shaft voltage equation and a stator q shaft voltage equation of a permanent magnet synchronous motor in a synchronous rotating reference frame are established; (2) according to the stator q shaft voltage equation in the step (1), discrete voltage equations of the permanent magnet synchronous motor are established in the current period and the previous period respectively; (3) changes in voltage items relevant to rotating speed are ignored, and the discrete voltage equations of the permanent magnet synchronous motor are subtracted to obtain a current increment formula of the permanent magnet synchronous motor; (4) a pulse transfer function between a current predicted value and a current detected value in the current period is obtained according to a transfer function of the permanent magnet synchronous motor and the current increment formula of the permanent magnet synchronous motor; (5) a closed loop pulse transfer function of a q shaft current loop by means of the current increment prediction algorithm is obtained according to the pulse transfer function, a pulse transfer function of a traditional current loop PI regulator, and the transfer function of the permanent magnet synchronous motor. The permanent magnet synchronous motor current increment prediction algorithm can be widely applied to the field of permanent magnet synchronous motor servo control.

The invention relates to a Buck converter based on variable conduction time control, belonging to the technical field of analog integrated circuits. An error current signal and an error voltage signalis generated by using a double-input and double-output error amplifier, and the error voltage signal is compared with a sampled voltage signal containing inductance current information to serve as aninput signal of a duty ratio modulator; variable current generated by a current multiplier is used as charging current of a charging capacitor, and the conduction time of the Buck converter is variable; the voltage at the switching node of the Buck converter is filtered and then compared with the voltage of the charging capacitor to serve as another input signal of the duty ratio modulator, a logic signal with a controlled duty ratio is generated and serves as a gate driving signal of a power tube of the Buck converter after dead zone control and driving, response speed is effectively improved, and undershoot or overshoot of the output voltage VOUT is reduced.

Disclosed are a circuit and a method for adaptively biasing a voltage regulator with minimal output overshoot. The circuit includes an adaptive bias current mirror circuit further including a first transistor and a second transistor, the first transistor and the second transistor having source nodes coupled to a drain node of the first transistor. The circuit includes a common node coupled to the source node of the first transistor and the source node of the second transistor, wherein a source degenerate resistor is coupled to the adaptive bias current mirror circuit and is coupled to the common node and wherein the source degenerate resistor is configured to limit an output peak current of the voltage regulator circuit.