963 results about "Linear control" patented technology

A foot operable controller for a surgical instrument having a main foot pedal assembly providing either proportional or linear control signals when moved laterally and in a vertical direction. Friction between an operator's foot and the foot pedal is minimized by a foot pad having a rotating heel plate. A neutral zone between left and right control positions of the foot pedal enables the operator to move his foot freely without changing control settings. Vertical displacement of the foot pedal is indicated by a plurality of mechanical detents during both upward and downward travel. Changing detent resistance alerts the operator to the vertical position of the foot pedal, indicating that further vertical displacement will change an instrument control signal corresponding to the new foot pedal position, thus providing sensory feedback to the operator indicating a change in the functional mode when the foot pedal is moved.

The invention discloses a three-dimensional formation reconfiguration method for multiple unmanned aerial vehicles based on particle swarm optimization and genetic algorithm. The method considers the position of the unmanned aerial vehicle in the ground coordinates and the speed, track angle and course angle of the unmanned aerial vehicle when establishing a formation model, carries out subsection linear disposal of the control input of each flying unit in the unmanned aerial vehicle, replaces the approximate subsection linear control input with the continuous control input, then carries out global search by the genetic algorithm, subsequently carries out partial searching by the particle swarm optimization algorithm, on the base thereof, the particle swarm optimization is used to guide the genetic algorithm to search a global optimum solution so as to figure out the subsection linear control input. Compared with the traditional method, the method provided by the invention has good real-time performance and rapidity and can be used for solving the formation reconfiguration problem of multiple space robots under complex and dynamic environment.

A catheter for use in a patient's heart, especially for mapping a tubular region of the heart, has a catheter body, a deflectable intermediate section and a distal a mapping assembly that has a generally circular portion adapted to sit on or in a tubular region of the heart. A control handle of the catheter allows for single-handed manipulation of various control mechanisms that can deflect the intermediate section and contract the mapping assembly by means of a deflection control assembly and a linear control assembly. The deflection control assembly has a deflection arm and a rocker member. The linear control assembly has a linear control member, an inner rotational member and a cam. A pair of puller members are responsive to the deflection control assembly to bi-directionally deflect the intermediate section. A third puller member is responsive to the linear control assembly to contract the generally circular portion of the mapping assembly.

A controller for use with a power converter including a switch configured to conduct to provide a regulated output characteristic at an output of the power converter, and method of operating the same. In one embodiment, the controller includes a linear control circuit, coupled to the output, configured to provide a first control signal for the switch as a function of the output characteristic. The controller also includes a nonlinear control circuit, coupled to the output, configured to provide a second control signal for the switch as a function of the output characteristic. The controller is configured to select one of the first and second control signals for the switch in response to a change in an operating condition of the power converter.

System and method for providing a programmable power supply. The programmable power supply may include a programmable hardware element (PHE) that couples to a power supply (DC-DC converter) and which in turn couples to a linear regulator. The PHE may implement a PID control algorithm that receives a measurement of the output power and may use PID and / or non-linear control to ensure that the power supply and the linear regulator maintain similar power levels. The PHE may be configured based on a graphical program, thus enabling fast and efficient modifications to the programmable power supply.

A circuit and method for controlling a switching regulator utilize a combination of variable off-time control (or frequency control) and variable peak current control to achieve high efficiency at a wide range of load conditions. A non-linear control circuit receives an error voltage and generates a first control signal for controlling a frequency control circuit and a second control signal for controlling a peak current control circuit. The frequency control circuit and the peak current control circuit operate in conjunction over the entire range of load conditions with the frequency control dominates at light load (or low power) conditions and the variable peak current control dominates at moderate to heavy load (or high power) conditions. The switching regulator transitions smoothly between frequency control and peak current control with continous loop gain throughout the transition region.

Abstract of Disclosure A computer-based system is described that provides users with the ability to develop high-fidelity digital quantitative representations of physical and chemical phenomena, and to employ an optimization-based approach to control associated physiochemical processes. The system includes a computational environment, intuitive user interface(s), integrated software libraries, analytical tools, and visualization / rendering engine that together provide an integrated framework for nanoscale modeling, analysis, simulation, and synthesis. Additionally, the system includes an optimal linear control synthesis methodology that incorporates a first order dynamic mathematical representation (of the conceptual molecular system) suitable for applying various pragmatic control system techniques including optimization of structured singular values, linear quadratic performance functions, Lyapunov criteria, or similar, for the purposes of nanoscale fabrication and molecular assembly.

System and method for managing batch fermentation in a biofuel production process. A nonlinear control model of yeast growth and fermentable sugar concentration for biofuel (e.g., fuel ethanol) production in a batch fermentation process (pure and / or fed-batch fermentation) of a biofuel production process is provided. Process information for the batch fermentation process is received, and the nonlinear control model executed using the process information as input to determine values of one or more fermentation process variables for the batch fermentation process, e.g., fermentation temperature and / or enzyme flow, for substantially maximizing yeast growth and achieving target fermentable sugar concentrations. The batch fermentation process is then controlled in accordance with the determined values for the one or more fermentation process variables to substantially maximize yeast growth and achieve target fermentable sugar concentrations, where substantially maximizing yeast growth and achieving target fermentable sugar concentrations substantially maximizes biofuel production in the batch fermentation process.

Embodiments discussed herein provide improved control of an unmanned aerial vehicle camera gimbal. In some embodiments, a linear control circuit is described that uses an operational amplifier that allows the system to retain its passive isolation of high frequency disturbances.

A voltage regulator with current-mode, dual-edge pulse width modulation (PWM) and non-linear control. The voltage regulator may include a top switch (e.g., MOSFET) configured to couple a power supply supplying an input voltage to a load. A linear control circuit of the regulator may use a first ramp signal to control turning ON of the top switch and a second ramp signal to control turning OFF of the top switch. A non-linear control circuit may turn ON the top switch upon detection of a load current step-up change to maintain an output voltage of the regulator within its regulation band. The non-linear control circuit may turn OFF the top switch upon a load current step-down change to prevent output voltage overshoot.

A linear motion control device for use in a linear control system is presented. The linear motion control device includes a coil driver to drive a coil that, when driven, effects a linear movement by a motion device having a magnet. The linear motion control device also includes a magnetic field sensor to detect a magnetic field associated with the linear movement and an interface to connect an output of the magnetic field sensor and an input of the coil driver to an external controller. The interface includes a feedback loop to relate the magnetic field sensor output signal to the coil driver input.

The invention discloses a linear control based automobile steering system, which comprises a signal acquisition part, a control unit part and a mechanical execution part and is characterized in that the signal acquisition part acquires a steering signal and a torque signal of a steering wheel, an angle signal of a wheel, a speed signal of the whole automobile, an acceleration signal and a side angular speed, and transmits the signals to the control unit part; and the control unit part analyzes and judges the signals, and outputs a control signal to control the motion of the mechanical execution part. The automobile steering system adopts the control of double motors, wherein an upper motor realizes real simulation of road induction, and a lower motor can realize the accomplishment of steering motion. Because the mechanical connection between the steering and the execution is cancelled, the steering and the execution have a modularized product respectively, so that the system is convenient to update and assemble so as to improve the safety factor of the automobile steering system.

A motor-driven electronic hydraulic braking system comprises a brake pedal, a pedal displacement sensor, a secondary master cylinder, a pedal simulator pressure sensor, a pedal simulator, pedal simulator solenoid valves, a push rod, an electrically-controlled linear movement module, a brake master cylinder and an ABS / ESP (anti-skid brake system / electronic stability program) module. The electrically-controlled linear movement module drives the push rod to move by means of driving a movement regulating mechanism through a motor, the motor is controlled through a displacement signal, and linear control on braking pressure is realized. The brake master cylinder passes the ABS / ESP module to be hydraulically coupled with vehicle wheel brakes. The ABS / ESP module can passively regulate pressure transmitted from the master cylinder to the wheel brakes, and can actively regulate the pressure of the brake of each wheel. The motor-driven electronic hydraulic braking system has the advantages of rapid response, accurate control on brake fluid pressure, capabilities of well simulating brake pedal feeling of a driver and maximally recovering braking energy, and the like; meanwhile, the system is designed with a dual failure protection mode, thereby having high safety and reliability.

The invention discloses a soft start device that can realize linear control, which comprises a working circuit, a soft start circuit and a start control circuit; the working circuit comprises a DC power source, a load capacitance, a power tube and a feedback circuit which are connected between the DC power source and the load capacitance and also a soft start circuit and a start control circuit, and the power tube is provided with a control end; the soft start circuit comprises a voltage generator, the output voltage of which is increased gradually after start, and an error amplifier, the input end of which is connected with the output end of the voltage generator; the input end of the error amplifier is connected between the output end of the power tube and the ground, while the output end of the error amplifier is connected to the control end of the power tube; when the start control circuit detects that the start begins, the soft start circuit is set to be in normal working state and a feedback circuit is set to be in off working state. The adoption of the device of the invention can avoid surge current at the moment when the power source charges the load capacitance at the instance when the circuit is electrified, can repeatedly use the existing error amplifier in the original circuit structure and save the areas and energy consumption of chips.

A voltage regulator may be configured to detect variation in load current and control transient response when the load current has a high slew rate or varies at high repetition rates. A linear control circuit may be employed to control charging of an output capacitor and a load of the regulator. Upon detection of high load current step-up change at high slew rates, a non-linear control circuit may be activated. The fast load current step change may be detected by comparing an output voltage of the regulator to a feedback input of an error amplifier of the linear control circuit. The output of the error amplifier may be clamped to prevent output voltage ring-back when using the non-linear control circuit or to control load release dip. Output voltage overshoot may be controlled by turning OFF a top switch that charges the output capacitor before the inductor current becomes zero.

The invention discloses a method for controlling a four-switch buck-boost DC-DC converter. The method integrates the advantages of the linear control and the nonlinear control, adopts the control of a current mode during the steady state and carries out the voltage sampling at a voltage output terminal; the sampling voltage and the benchmark voltage are input in an error amplifier; the output signal of the error amplifier is used as the benchmark input of a current comparator; the output terminal of the error amplifier is also connected with a compensation network which consists of resistances and capacitors; when the loaded jumps, the nonlinear control is carried out. The invention also discloses a device used for implementing the method. The invention realizes the application of the nonlinear control on the four-switch buck-boost topology, simultaneously solves the technical problem that the oscillation occurs when the load jumps during the nonlinear control process, thereby leading the output voltage to reach the stable value quickly, and improving the response speed of the buck-boost converter.

The invention relates to an LED driver with an adjustable conduction time. The LED driver with the adjustable conduction time comprises one way or multiple ways of LEDs, a conductive threshold value setting module and a controlling module, wherein the LEDs are conducted when power supply voltage rises to LED conduction voltage, the conductive threshold value setting module is used for setting the LED conductive time, and the controlling module is used for disconnecting the one way or the multiple ways of LEDs when the power supply voltage rises to exceed an LED conduction voltage setting threshold value, and connecting the one way or the multiple ways of LEDs when the power supply voltage reduces to exceed the LED conduction voltage setting threshold value according to the conduction time of the LEDs, wherein the setting threshold value is related to the LED conduction threshold value. Due to comparison of an input voltage and an LED voltage drop, conduction time of the LEDs is controlled, the problem that voltage differences of the input voltage and the LED voltage are too large is solved, efficiency of a linear LED driving circuit is improved, circuit heating value is reduced, and application reliability is enhanced. In addition, the LED driver with the adjustable conduction time flexibly achieves the compromising design of high efficiency of the linear controlling scheme and a PF value through controlling the LED conduction time.

The invention discloses an autonomous vehicle following system. The system is provided with a front anti-collision millimeter-wave radar installed in front of a vehicle. The front anti-collision millimeter-wave radar outputs signals to a main control unit through a CAN bus. The main control unit outputs alarm signals to an alarm reminding unit and outputs brake signals to a linear control brake unit. Each of the two sides of the front anti-collision millimeter-wave radar is provided with an ultrasonic radar which outputs signals to an ultrasonic radar control unit. The ultrasonic radar control unit outputs signals to the main control unit through the CAN bus. The autonomous vehicle following system has the beneficial effects that in combination with the low-cost ultrasonic radar, the relative distance of a near-distance target is accurately measured, and the defect that the near-distance measurement error of the millimeter-wave radar is large is overcome.

The invention discloses an iterative learning trajectory tracking control and robust optimization method for a two-dimensional motion mobile robot. The method includes the steps that firstly, a kinetic equation of a two-dimensional motion mobile robot discrete non-linear motion system model is established; a discrete non-linear state space expression is established; a P type open-closed loop iterative learning controller based on the iterative learning control technology is established; then the robust convergence of the established discrete non-linear control system is theoretically analyzed; then parameter item splitting is conducted on control gains of the P type controller, meanwhile, a quadratic performance index function based on controller parameters is designed, and the purpose is to optimize the control parameters; finally, monotone convergence characteristics of output errors and parameter selection conditions generated when a control algorithm acts on a controlled system are analyzed and optimized, and the two-dimensional motion mobile robot can rapidly track an expected motion trajectory at high precision. The method has the advantages that the robust optimization iterative learning controller is suitable for tracking control in an ideal state and suitable for trajectory tracking tasks under the condition that interference exists outside. A designed iterative algorithm is simple and efficient, introduction of a large number of additional parameter variables is not needed, and engineering realization is easy.

In a magnetic disk storage apparatus, when a drive current of the voice coil motor is small, the head drive control circuit executes the linear drive mode under which the voice coil motor is driven in a linear control manner, whereas when the drive current is large, the head drive control circuit executes the pulse drive mode under which the voice coil motor is driven in a pulse width control manner. Both modes are carried out by employing a commonly-used output amplifier that is arranged as a push-pull type output circuit made of both a push-driving output transistor and a pull-driving output transistor. An operation mode of this output amplifier is set to an AB-class operation during the linear drive mode, whereas the operation mode of this output amplifier is set to a B-class operation during the pulse drive mode.

The invention relates to a variable propeller pitch control system of a wind driven generator which is characterized in that the variable propeller pitch control system consists of a central control cabinet, a plurality of shaft cabinets connected in parallel and controlled by the central control cabinet as well as a group of DC motors and transmission devices which are singly controlled by each shaft cabinet; the central control cabinet includes a PLC control unit and a control interface. The PLC control unit of the system of the invention realizes the multiple functions of closing the loop at the rotating angle position of a blade, charge control for a battery, controlling the temperature of a box body, fault processing, etc. An upper computer transmits a single position signal to the PLC control unit; when an error does not happen or happens to the position signal, then the PLC control unit considers the error to be a fault and sends out a command duly to adjust the blade to a safe position, namely a feathering position, thereby simplifying the control procedure of the blade and increasing the running reliability of the blade; the driving of the blade is realized by the DC motor; the control characteristic is more stable due to linear control.

A self-sourcing exercise bike with a linear digital control magnetic resistance braking apparatus comprises a generator, a power converter, a digital control system, a magnetic braking resistance and a LED control panel. This apparatus uses a linear control method to control the change of the magnetic resistance, and the magnetic resistance braking apparatus uses a method of changing inductance and a controlling way thereof to achieve the goal of controlling the variation of the magnetic resistance braking force. This bike makes the user or rehabilitant to linearly adjust the resistance force or torque according to the speed of the exercise bike and the presetting resistance force, and easily start up the power system in the initial stage.

A system for controlling a soft start for a switching converter includes a digital feedback control system for receiving an analog voltage signal representing the output of a switching converter, for digitally processing the analog voltage signal by comparing it to a corrected reference voltage to generate a voltage error signal and for generating drive signals to control the operation of the switching converter to provide a regulated output. A microcontroller providers a secondary feedback loop for generating the corrected reference voltage. The secondary feedback loop enabling the output voltage signal to vary linearly over time during a soft start.

A method and apparatus is featured for providing linear control of a regulated electrical property (e.g., current or voltage) in a switch mode power supply of a thermal processing system that includes an inductive element and at least one switching element. The method and apparatus feature structure, or steps, for generating a nonlinear model that predict values for a regulated electrical property of the inductive element based on a given duty cycle of the at least one switching element and structure, or steps, for generating a nonlinear model that determines a duty cycle for the at least one switching element based on the nonlinear predictive model for the regulated electrical property, the nonlinear model determining the duty cycle such that a linear relationship results between the regulated electrical property and a selected value. A method and apparatus is also featured for providing cross regulation between pre-regulator and post-regulator power stages of a switch mode power supply of a thermal processing system.

The invention discloses a composite linear control method of a hysteresis characteristic of a piezoelectric ceramic actuator and a realization circuit thereof. The composite linear control method comprises a feedforward linear control process and a closed-loop linear control process, wherein in the feedforward linear control process, a built mathematical model of the piezoelectric ceramic actuator is utilized to construct a hysteresis component observer which observes the hysteresis components of the piezoelectric ceramic actuator under the action of control voltages, compensating voltages required by compensating the hysteresis components are calculated, and the compensating voltages and the control voltages are overlapped to obtain actual driving voltages which are acted on the piezoelectric ceramic actuator to generate displacement output; in the closed-loop linear control process, a displacement sensor is utilized to obtain feedforward linear errors and the closed-loop control is utilized to reduce the errors to be zero; and a composite linear controller comprises a control signal generator, an analog to digital converter, a composite linear controller, a digital to analog converter, a power amplifier, the displacement sensor and a signal conditioning circuit. According to the invention, the hysteresis nonlinearity relation between the output displacement of the piezoelectric ceramic actuator and the control voltages can be linearized, thus simplifying a control algorithm of the piezoelectric ceramic actuator greatly and improving the positioning accuracy of the piezoelectric ceramic actuator.

The invention relates to a photoelectric light-guide switch module controlling and adjusting photoelectric signals to be input into a device. According to the invention, an SMD IR tube and an SMD PT tube are adopted as an optical signal transmitting and receiving device. A light guide tube or an optical fiber structure is utilized for realizing the switching off and switching on of the photoelectric switch and the precise control of intensity of the photoelectric signals. The photoelectric light guide switch module includes a cross-shaped mechanical shaft, a spring and an upper shell and a lower shell having a buckling lock structure. The switch module also includes the SMD IR tube, a coupling component, a light guide tube or an optical fiber, a focusing part, the SMD PT tube and a prism, a light gate or other switch control components in linkage with a mechanical key shaft. According to the invention, the switching on and off of the photoelectric switch can be realized through moving the switch control component relative to the light guide tube or the optical fiber. Also, linear control of photoelectric signals is realized and game players can feel speed and power in game operation. The switch module is especially suitable for game players.