753 results about "Pressure feedback" patented technology

Various devices, systems and methods for providing effective, long term and reliable use of pressure feedback in VADs. Exemplary embodiments are described which provide for direct LV pressure measurement, non-invasive calibration techniques to detect ventricular collapse and recalibrate the feedback mechanism, improved pressure sensor designs with reduced drift, and barometric pressure correction schemes. These devices and methods may be used alone or in combination with each other, and may also be combined with other feedback mechanisms.

The invention discloses terminal equipment and a method for feeding back pressure by using the same. The terminal equipment can present different information feedback to users according to the pressure born by the terminal equipment, so that the user can determine the pressure applied at present according to the feedback information and perform corresponding processing. The method comprises the following steps: sensing the applied pressure and determining the amplitude of the applied pressure; determining the amplitude range which the amplitude belongs to; acquiring pressure feedback information corresponding to the amplitude range, wherein the corresponding relationship between each amplitude range and the pressure feedback information is preset in the terminal equipment and different amplitude ranges correspond to different pressure feedback information; and performing feedback according to the acquired pressure feedback information. The invention also discloses another terminal equipment and method for feeding back pressure by using the same.

A fuel control system uses a fuel pump powered by a variable speed pump motor controlled by a closed loop electronic feedback system that tracks motor speed and corrects fuel pump motor speed so that the fuel pump delivers flow according to a desired flow schedule based on the pressure feedback from the manifold.

A sound producing system includes a loudspeaker to generate an audible signal. A transducer generates a pressure feedback signal from the audible signal. A controller produces a controlled signal for application to the loudspeaker. The controller derives the controlled signal from the pressure feedback signal and an audio input signal. The controlled signal improves the Sound Pressure Level (SPL) frequency response and reduces distortion within a selected bandwidth of the loudspeaker.

A pneumatic syringe driver having a control module for regulating pressure applied to the plunger of an associated syringe is disclosed. The syringe driver is adapted for receiving a compressed gas canister and for enabling the selective release of gas from the canister into a chamber, one wall of which being formed by the syringe plunger via a three-way valve. The valve also enables the selective venting of gas from the canister into the atmosphere, thereby forming a venturi which reduces the pressure in the chamber and causes the syringe plunger to be withdrawn into the chamber. A pressure sensor in communication with the control module is provided for pressure feedback. Pushbuttons or switches in communication with the control module are provided for defining the syringe driver operation. The device is suited for the selective inflation and deflation of a balloon attached to the syringe driver for a balloon angioplasty procedures.

A gas regulator includes an actuator, a regulator valve, and a secondary device. Downstream pressure feedback is provided to the actuator and the secondary device via a Pitot tube disposed within an outlet of the regulator valve. The Pitot tube has a first branch having an end connected to the actuator to place the actuator control cavity and diaphragm in fluid communication with downstream pressure within the outlet for maintaining the outlet pressure at an actuator setpoint pressure. The Pitot tube also has a second branch having an end connected to the secondary device to place the interior of the secondary device in fluid communication with downstream pressure within the outlet for responding to changes in the downstream pressure when the outlet pressure diverges from a predetermined normal operating pressure range.

A servo motor for driving a die is provided with position and speed detectors. Further, a pressure sensor for detecting the pressure applied to a workpiece is provided. In the servo motor control unit, the smaller one of the speed command obtained by feedback control of the position and the speed command obtained by the pressure feedback control is selected as an output of a comparator. Based on the speed command output from the comparator, feedback control of the speed is performed and the servo motor is driven. In the state where the die does not press against the workpiece, a pressure error is large, the speed command by pressure control becomes large, and the speed command by position control becomes small. Therefore, position control is performed. When the workpiece is pressed, the position error increases, and the pressure error decreases, a speed command by pressure control is employed and pressure control is performed.

A diagnostic system according to the present invention diagnoses system failure of a secondary air injection system. The secondary air injection system includes a pump that provides air to an exhaust system via a conduit and a valve that controls the flow of air through the conduit. A pressure sensor measures pressure in the conduit. A controller predicts pressure in the conduit during first, second and third operational phases of the secondary air injection system. The controller compares the measured pressure to the predicted pressure to evaluate operation of the secondary air injection system. During the first phase, the secondary air injection system is used to reduce vehicle emissions. During the second phase, the valve is shut while the pump is on. During the third phase, the pump is turned off while the valve is closed.

A starter air valve assembly includes a valve body, a flow control valve, a rate control servo mechanism, and a valve actuator. The valve body defines a flow passage having at least an inlet port and an outlet port. The valve is disposed at least partially within the flow passage and is moveable between an open position and a closed position. The rate control servo mechanism is adapted to receive pressurized fluid and is configured, upon receipt of the pressurized fluid, to supply a controlled flow of the pressurized fluid. The valve actuator is coupled to the valve and is in fluid communication with the rate control servo to thereby receive the controlled flow of the pressurized fluid. The valve actuator is configured, upon receipt of the controlled flow of the pressurized fluid, to move the valve between the closed position and the open position at a substantially controlled rate.

The invention relates to a dynamic soft reduction method for detecting the tail end of a solidified liquid core of a casting blank based on pressure feedback, belonging to the technical field of metallurgy continuous casting control. The method comprises the following steps of: firstly, establishing a control platform for remotely and automatically adjusting roll gaps of all sector sections on a continuous casting machine, and calculating the stress of the casting blank in different sector sections by utilizing the detection result of pressure sensors installed on all the sector sections; detecting the stress difference of the casting blank in each sector section during roll gap variation by changing the roll gap contraction size of each sector section; judging the position of the tail end of the solidified liquid core of the casting blank according to the stress difference between the casting blank with the liquid core and the casting blank without the liquid core; and finally, dynamically adopting different reduction quantities in all sector sections of a casting machine by using a soft reduction control system according to the position of the tail end of the liquid core judged by the method. The method for judging the tail end of the solidified liquid core of the casting blank is directly obtained by calculating the real-time stress of the casting blank. Because the calculation of casting blank surface temperature and blank shell thickness does not need a large quantity of mathematical models, the calculation method is simple and effective and ensures the stability and the execution efficiency of a casting machine control system.

A hand-grippable adhesive tape applicator is provided for building construction and other environments. Pressure feedback and integrated slidable cutting mechanism features are included which provide improved tape application performance. Unique tape supply spool and take-up reel assemblies also are provided which enhance tape applicator performance. A patterned applicator roller also is provided to allow tape application to be performed with reduced user-applied force.

The invention discloses a driving and energy recovery system for a hybrid excavator, which is characterized in that a master valve, an engine, a master variable pump, a recovery motor, an auxiliary variable pump, a motor controller and an energy storage element are all connected with a hybrid control unit; the hybrid control unit is also provided with an operating signal input interface and a pressure feedback signal input interface; and a driving motor, a recovery motor, a turning motor and the energy storage element are all connected with the motor controller. The driving and energy recovery system for the hybrid excavator can recover energy comprehensively, has good energy-saving effect and can not affect the stable operation of the engine.

A closed loop turbine speed control system for a turbine power production system including a closed loop hydrostatic transmission system for the transfer of energy from a wind turbine rotor to a generator. A displacement actuator is arranged for receiving a displacement control signal from the control system and for controlling a displacement of the displacement motor. The control system includes a turbine rotor speed feedback control loop for calculating the displacement control signal based on deviations of a turbine rotor actual rotational speed from a turbine rotor set rotational speed. In addition a hydraulic pressure meter measures the hydraulic pressure of the hydrostatic system and provides a hydraulic pressure signal as an input to a pressure feedback control loop for stabilizing the displacement control signal based on the hydraulic pressure signal.

The invention relates to a flow distributing type hydraulic oscillation circumferential impactor. The flow distributing type hydraulic oscillation circumferential impactor comprises a shell connector, a double-bus jet generator, a flow distributor, a gland, a hydraulic drive hammer and a transmission short joint. The double-bus jet generator abuts against the interior of the shell connector. The hydraulic drive hammer is installed at the upper portion of the transmission short joint. The flow distributor and the gland are located between the double-bus jet generator and the hydraulic drive hammer. The transmission short joint is screwed in the lower end of the shell connector and abuts against the gland. An annular groove and a flow releasing channel are formed in the inner wall of the shell connector. The annular groove corresponds to a returned liquid outlet in the outer wall of the double-bus jet generator, and a drainage hole is formed in the transmission short joint. The double-bus jet generator is a cylinder with a center runner. The center runner is divided into a left branch runner and a right branch runner through a check block. The inlet and the outlet of a pressure feedback channel in the double-bus jet generator are communicated with the center runner. Each branch runner is divided into two parts through the flow distributor. The hydraulic drive hammer is provided with symmetric arc bosses. Arc cavities contain the arc bosses. According to the flow distributing type hydraulic oscillation circumferential impactor, no weak part exists, the service life is long, and the impact effect is good.

[Problem] To always perform accurate pressure feedback control, and control the discharge flow rate of liquid chemical with high precision, even in situations in which the pressure setting value of the operation pressure differs due to changes in the type of liquid chemical, etc.

[Means of solution] A pump 11 has a pump chamber 13 and an operation chamber 14 separated by a diaphragm 12 comprised of a flexible membrane, and performs the intake and discharge of liquid chemical in accordance with the change in pressure inside the operation chamber 14. An electro-pneumatic regulator 32 supplies operation air to the operation chamber 14. In addition, in the present system, a plurality of pressure sensors 51, 63 having different pressure detection ranges is provided as pressure detection means for detecting the operation air pressure. A controller 40 selectively employs any of the detection results of the plurality of sensors 51, 63 in accordance with the pressure setting value of the operation air that is set for each use, and performs pressure feedback control.

A hydraulic system of shield spiral conveying machine with ratio feedback control and energy storing device for oil supplement consists of a three-position and four-way solenoid change valve, a motor, a rotation sensor, a one-way valve, a liquid-controlled one-way valve, a throttle valve, a two-position and two-way solenoid reversal valve, a shift sensor, a hydraulic cylinder, a range switch, a stop ball valve, a unloading valve, an overflow valve and an energy storing device. The machine has a sensor to monitor rotation and makes variable pump controlled according soil cabin pressure so as to control soil discharge volume and to achieve a hydraulic control system of a continuous real time controllable spiral-conveying machine. The energy-storing device is used oil supplement to close exhaust outlet reliably when accident occurs to guarantee safety for tunnel engineering. The electric feedback and ratio feedback are used to control turbulence to soil body when shield tunneling and reduce settlement of earth surface. The machine can be adaptable for various strata reliably.

A three-way proportional pressure reducing valve includes a valve body and a cylindrical valve spool. Five chambers are formed between the valve body and the cylindrical valve spool, respectively a fifth chambers, a first chamber, a second chamber, a third chamber and the fourth chamber. The first chamber connected to a high pressure inlet port P, the second chamber connected to a oil port A and the third chamber connected to a low pressure outlet port T. A first control edge being fitted between the first chamber and the second chamber, a second control edge being fitted between the second chamber and the third chamber. A first passage being located between the fifth chamber and the second chamber for connecting the second chamber to the fifth chamber, a second passage being located between the fourth chamber and the third chamber for connecting the fourth chamber to the third chamber. The present invention mainly provides a three-way proportional pressure reducing valve which can be achieved to control arbitrary pressure course change between pressure P at the constant pressure source and the oil tank at zero pressure by two damping adjustable control edges and the pressure feedback means of the chamber. The aim of the present invention is to solve the technological problem of change-over only within two limit value of zero pressure and maximum pressure and unable to control the intermediate pressure, which exists in the technology now available.

A pulse width modulated (PWM) valve-based hydraulic control system is disclosed. In one embodiment, a feedback control system includes a controller that receives a pressure command signal and a pressure feedback signal. The controller generates a duty cycle control signal that controls a PWM valve. The PWM valve provides a control pressure Pc to control a load, such as an actuator of an automatic transmission system. A pressure sensor measures the control pressure Pc and provides the pressure feedback signal. In another embodiment, a compensator provides compensation for linear and nonlinear effects in the pressure feedback signal, based at least in part, on other inputs, such as fluid temperature. In other embodiments, a plurality of controllers are provided, and a controller is selected by a switching logic processor, or by phase-in and phase-out filters, based on the pressure feedback signal and other inputs. A re-calibration process for the Pc versus duty cycle response of the PWM valve is also disclosed. The re-calibration method updates the feedback control system processes to maintain performance despite variations due to wear, temperature, and other factors.