43 results about "Exponential stability" patented technology

A six degree-of-freedom trajectory linearization controller (TLC) architecture (30) for a fixed-wing aircraft (46) is set forth. The TLC architecture (30) calculates nominal force and moment commands by dynamic inversion of the nonlinear equations of motion. A linear time-varying (LTV) tracking error regulator provides exponential stability of the tracking error dynamics and robustness to model uncertainty and error. The basic control loop includes a closed-loop, LTV stabilizing controller (12), a pseudo-inverse plant model (14), and a nonlinear plant model(16). Four of the basic control loops (34, 36, 40, 42) are nested to form the TLC architecture (30).

A controller design for switching between m linear multivariable controllers each of whom stabilizes a linear plant has been presented. A Youla-Kucera factorization was exploited in the interest of obtaining a closed-loop system that is exponentially stable for any switching signal σ(t) in the absence of plant model uncertainty. Robustness to practical model uncertainty was also considered and lower and upper bounds on the tolerable magnitude of unstructured additive plant uncertainty were presented. Numerical example demonstrated that the two controller degrees of freedom in the proposed controller design could be used to separately modify the closed-loop steady-state (with respect to σ(t)) performance and the switching transients.

The invention discloses a bridge crane control method based on a sliding mode surface, and provides a novel control method based on a sliding mode surface for positioning and anti-swing tasks in a bridge crane conveying process. The method comprises the steps that an original crane model is converted into a line-similar mode through coordination transformation at first; then, the novel sliding mode surface is designed, and a corresponding nonlinear control algorithm is built for keeping the system state always in the sliding mode surface; and finally, the Lyapunov method strictly proves that a system balance point can reach approximate exponent stability as long as parameter selection meets conditions given in the method. Compared with an existing crane control method (which can only ensure asymptotic convergence), the method is higher in convergence speed (approximate to exponential convergence). In addition, control input is smoother compared with general full-state feedback methods and is beneficial to practical application. Stimulation and experiment results prove that the method is high in positioning speed, good in anti-swing effect and quite high in robustness for various kinds of external disturbance.

A method controls a micro-grid connected to a power distribution system. The method determines parameters of a model of dynamics of the micro-grid using measurements of power flow at a point of common coupling (PCC) of the micro-grid with the power distribution system. The model is exponentially stable on a voltage set-point at the PCC and the method determines, using the parameters of the model, an amount of reactive power required to maintain the voltage at the PCC asymptotically stable on the voltage set-point. Next, the method controls a generator of the micro-grid to produce the amount of reactive power.

The present invention discloses a non-fragile dissipative filtering method of a nonlinear networked control system. The method comprises the steps of firstly establishing a nonlinear networked filtering error system model on the conditions of considering the time delay and the packet loss of the nonlinear networked control system and the perturbation of the filter parameters, then constructing a Lyapunov function, and then utilizing a Lyapunov stability theory and a linear matrix inequality analysis method to obtain the sufficient conditions of the mean square exponential stability of a nonlinear networked filtering error system and the existence of a non-fragile dissipative filter, utilizing a Matlab LMI tool kit to solve, and definding a non-fragile dissipative filter parameter matrix. The method of the present invention considers the random time delay and the pocket loss situations between the sensors and the filters, is suitable for the general dissipative filtering including the H-infinite filtering, and enables the conservatism of the non-fragile dissipative filter design to be reduced. Moreover, a non-modeling state of the system is considered when a full-order filter is designed, thereby being able to reduce the calculation burdens and the design cost.

A simple and robust discrete-time induction motor control technique employs a control algorithm that estimates load torque and rotor resistance from the measured rotor velocity of the motor to be controlled. The estimates of load torque and rotor resistance are employed to generate periodic estimates of parameters that are employed to control first and second harmonic signal generators. A switch controls which of the signal generators supplies a control signal to the motor at any given moment. The two signal generators work in turn such that while one produces the motor control signal, the other one is being readjusted to the new set of parameters by the parameter controller. The control method can be considered as a generalization and modification of Field Oriented Control. In a "non-adaptive" modification, it ensures global exponential stability of a closed-loop system, if at least local stabilization of the system by static control is possible, for given parameter estimates. In an adaptive version, it provides identification and global exponential stabilization of the system.

The invention provides an anti-saturation self-adaptive pseudo-proportion integration differentiation (PID) sliding mode fault-tolerant control method for a high-speed train and the method can improvethe effect of tracking a desired track of a high-speed train. The method includes the following steps: establishing a high-speed train dynamic model having an actuator fault, actuator asymmetric nonlinear saturation constraint and integral quadratic disturbance; giving the position and speed of a desired track, and establishing a desired track model; establishing an actuator auxiliary saturationcompensation system; based on the established high-speed train dynamic model, desired track model and actuator auxiliary saturation compensation system, calculating a track tracking error; based on the calculated track tracking error, constructing a pseudo-PID sliding mode surface; and based on the constructed pseudo-PID sliding mode surface, determining self-adaptive control laws, wherein the self-adaptive control laws include: a nominal control law for realizing exponential stability, a compensation control law for suppressing actuator faults and the influence of integral quadratic disturbance, and a self-adaptive law. The invention relates to the technical field of rail transportation control.

The invention discloses a random fault detection method of a networked control system with packet loss. The method, which takes into account the fact that a networked control system has the problems of random packet loss, quantization error and random faults, includes the following steps: building a model of a networked control system with random faults; building a model of a fault detection filter; introducing a residual evaluation mechanism to detect whether there is a fault; obtaining sufficient conditions for the exponential stability in mean square of an augmented system and the existence of a fault detection filter through the Lyapunov stability theory and a linear matrix inequality analysis method; using a Matlab LMI tool kit to solve the optimization problem, and giving optimal parameters (as shown in the description) of the fault detection filter; and judging whether there is a fault according to the established residual mechanism. The method takes into account the fact that a fault occurs randomly and the occurrence probability of faults satisfies the Bernoulli distribution. The technical scheme is suitable for general fault detection methods. The conservative property is reduced.

The invention discloses a noise and disturbance inhibition method for an optical voltage sensor based on dual closed-loop detection, belonging to the technical field of fiber voltage sensors. The method comprises that a mathematic model of an optical voltage sensor system is established based on a four-mode modulation technology; a state equation and a dynamic equation of the system are established; and a feedback gain matrix Kc is determined, so that the optical voltage sensor closed-loop system satisfies the index stability. Based on the four-mode modulation technology, the method combines influential factors which influence the detection precision for the optical voltage sensor to provide a robustness control scheme, so that cross interference between two closed loops can be realized, and the optical voltage sensor can be widely applied to power systems.

The invention discloses an Hinfinite control method of a networking linear parameter changing system. On the condition that random packet loss exists in signal transmission of the networking linear parameter changing system, a closed-loop networking linear parameter change changing control system model is established firstly, and then an appropriate Lyapunov function is constructed, thereby obtaining a sufficient condition of a fact that a stable mean square index of the networking linear parameter changing control system is realized and an Hinfinite controller exists. By means of an approximate primary function and grid technology, a problem of solving an original infinite-dimensional linear matrix inequality set is approximated to a problem of solving a finite-dimensional linear matrix inequality set, and the gain of a corresponding Hinfinite controller is defined to K(rho)=VB1<-1>(rho)P11<-1>(rho)B1(rho)V<T>M. According to the Hinfinite control method, a packet loss condition in a process of sensor-controller and a process of controller-executor are considered. The packet loss probability accords with Bernoulli distribution, and higher practical value is obtained. Hinfinite performanace restriction which depends on a parameter is presented. Conservatism of the Hinfinite control method is reduced.

Systems, methods, and computer program products for autonomous car-like ground vehicle guidance and trajectory tracking control. A multi-loop 3DOF trajectory linearization controller (300) provides guidance to a vehicle having nonlinear rigid-body dynamics (332) with nonlinear tire traction force, nonlinear drag forces and actuator dynamics. The controller (300) may be based on a closed-loop PD-eigenvalue assignment and a singular perturbation (time-scale separation) theory for exponential stability, and controls the longitudinal velocity (Vx,sen) and steering angle (delta) simultaneously to follow a feasible guidance trajectory. A line-of-sight based pure-pursuit guidance controller (502) may generate a 3DOF spatial trajectory that is provided to the 3DOF controller (300) to enable targetpursuit and path-following/trajectory-tracking. The resulting combination may provide a 3DOF motion control system (500) with integrated simultaneous steering and speed control for automobile and car-like mobile robot target pursuit and trajectory-tracking.

The invention discloses a signal detection method and circuit for a high precision optics voltage transformer and belongs to the technology field of an optics voltage transformer. The signal detection method and circuit for the high precision optics voltage transformer utilizes a band-pass filter of a narrow-band to replace the band-pass filter of a wide-band, utilizes a digital low pass filter and a control unit to replace a primary signal processing unit; and utilizes a robust control algorithm to obtain index stability during the signals detection process to improve the optics voltage transformer dynamic property which varies with the luminous intensity. The signal detection method and circuit for the high precision optics voltage transformer restrains white noises very well to obtain a closed loop error signal of high precision. By utilizing the detection method and circuit, the optics voltage transformer obtains +/- 0.2% precision, 24.5 kilohertz wide-band and 25.2 microseconds speediness step response which satisfy the application of electricity measuring and electricity protection fields.

The invention discloses a near-infrared non-invasive detection method for the concentration index of human hemoglobin. The near-infrared non-invasive detection method comprises the following steps offirstly respectively placing a photoelectric receiving tube on three positions of the surface of a human tissue to be detected, arranging three light-emitting diodes LS with different light-emitting wavelengths at the same positions of the extending lines of the connecting lines of the three photoelectric receiving tubes; then detecting the scattering light intensity received by all the photoelectric receiving tubes, calculating the optical density OD, and calculating the relative change amount delta OD (lambda i) of the optical density when the wavelength is lambda i according to the OD (k, lambda i); finally, calculating the concentration index tHI of the hemoglobin concentration index of the tissue to be detected according to the calculated delta OD(lambda i). The near-infrared non-invasive detection method disclosed by the invention has the beneficial effects that by adoption of three-wavelength light sources and three detectors, the benefit for improving the detection accuracy andeliminating the influence of the outer-layer covering tissue is achieved; the light-emitting diodes are adopted as the light sources, so that the detected the hemoglobin concentration index of the tissue is reliable; the detected the hemoglobin concentration index of the tissue is in direct proportion to the total concentration of the hemoglobin in the tissue, and the percentage of the concentration change of the hemoglobin in the tissue to be detected can be reflected.

The invention discloses a time delay compensation method of a networked inverted pendulum system having input constraints. The time delay compensation method comprises the steps of: firstly, acquiringa state-space equation of the inverted pendulum system; secondly, establishing a discrete switching system model of a networked inverted pendulum control system based on the obtained state-space equation; and finally designing a state feedback controller satisfying the input constraints, so that the networked inverted pendulum control system is exponentially stable. The time delay compensation method solves the problem of time delay compensation in a networked control system, further solves the input constraint problem existing in the actual system, and realizes stable pendulum control of thenetworked inverted pendulum system having the input constraints; in addition, the time delay compensation method is not limited to the example, and the result of the time delay compensation method isof important reference significance to an actual networked control system.

The invention discloses a random fault detection method of a nonlinear networked control system and belongs to the field of networked control systems. The method includes the following steps: firstly,random packet loss and random time delay are described by a unified model, a discrete networked control system model is established, a fault detection wave filter is designed subsequently, a wave filter error system is constructed, a residual error evaluation mechanism is introduced to judge whether a fault occurs or not, sufficient conditions of the mean square exponential stability of the wavefilter error system and the existence of the fault detection wave filter are obtained by using the Lyapunov stability theory and a linear matrix inequality (LMI) method, and an optimization problem issolved by a Matlab LMI toolbox to provide optimal fault detection wave filter parameters. The method of the invention takes into account sensor saturation, random faults, packet loss, time delay andnonlinearity in the system in actual situations, meets Bernoulli distribution during occurrence of conditions, is suitable for general fault detection and reduces the conservatism.

The invention discloses a design method for an optimal controller of a linear discrete time system with control time delay. The method converts the linear discrete time system with control time delayinto an equivalent linear discrete time system with no control time delay through a multi-step transformation of a memorized memory; then obtains a controller of the linear discrete time system with control time delay by designing a finite time optimal controller of the equivalent linear discrete time system without control time delay; and obtains the controller of the linear discrete time systemwith control time delay by designing an infinite time optimal controller of the equivalent linear discrete time system without control time delay. According to the design method for optimal controllerof linear discrete time system with control time delay, an optimal control for multi-step transformation of a linear discrete time system with control time delay is provided on the basis of memoryless transformation, , and the dimension of the system will not increase and the obtained optimal controller can stabilize a closed-loop system index when using such transformation.

The invention discloses a high-dynamic control method for a fiber-optic gyroscope. The high-dynamic control method comprises the following steps that: 1, the dynamic performance of a fiber-optic gyroscope is analyzed; 2, a mathematical model of a closed-loop control system of the fiber-optic gyroscope is established under the condition of considering noise, time lag and parameter uncertainty; and 3, a control algorithm of the fiber-optic gyroscope is optimally designed, and a state feedback control law is optimally designed, so that the exponential stability of the system is improved, the closed-loop system is still a solution to the control problem meeting the performance index requirement under the condition that noise, time lag and parameter uncertainty exist, and finally, the robust stability of the system can be improved.

The invention discloses a switching system method and system for 12-1[infinity] control based on a network control system, a controller and a control method. The method comprises the following steps:establishing a continuous time network control system model; discretizing the continuous time network control system to establish a discrete time sampling system; according to the number of lost packets, modeling a sampling system into a discrete time switching system, designing a sampling controller for ensuring the index stability and 12-1[infinity] performance of the system. Due to the design of the steps, a plurality of complex systems which cannot be described by a single model can be described, the stability of the system under the condition of packet loss can be researched, and externalinterference can be suppressed.

The invention provides a method for analyzing the global stability of a fluid conveying pipe-nonlinear energy trap system, and belongs to the technical field of system stability proving and analyzingin a control system. According to the method, a high-order partial differential model of a fluid conveying pipe-nonlinear energy trap system is established on the basis of a target energy transfer theory, is discretized into a second-order nonlinear ordinary differential form through a Galerkin approximation method, and is further converted into a quadratic model containing gradient information for the first time; and a global stability criterion of the system is obtained through an energy disturbance technology, and a theoretical result is finally verified through a numerical method. According to the method, the theoretical proving problem of the effectiveness of the nonlinear energy trap in the aspect of vibration control of the fluid conveying pipe is solved for the first time, and thestrict analysis process that the global stability is exponential stability is given.

The invention discloses a noise spectrum analysis and signal-to-noise ratio optimization method for a fiber-optic gyroscope. The method comprises the following steps of: 1, demodulating by using a sine wave modulation technology to obtain a closed-loop error of a closed-loop fiber-optic gyroscope system; 2, based on the closed-loop error model, establishing a dynamic equation of the fiber-optic gyroscope by considering parameter uncertainty; and 3, designing a feedback control matrix Kc of the closed-loop fiber-optic gyroscope system, so as to enable the fiber-optic gyroscope to meet the exponential stability and to optimize the linearity and the detection precision of the fiber-optic gyroscope system under the conditions of parameter uncertainty, nonlinearity and disturbance on the premise of ensuring that the fiber-optic gyroscope has the required H infinity performance. According to the invention, the closed-loop error is modulated to high frequency so as to eliminate the influence of interference light intensity and stray light interference, the nonlinear interference effect, light intensity fluctuation and inevitable noise are considered, and a dynamic model of a closed-loop fiber-optic gyroscope system is established. Then, a robust control algorithm is designed to optimize the performance of the fiber-optic gyroscope system.

The invention discloses an index stability analysis method of a DC/DC converter. The method at least comprises the following steps: establishing an augmented cycle switching system model of the DC/DCconverter according to an operation mode of the DC/DC converter; establishing a DC/DC converter system index stability judgment basis according to a discontinuous control theory; converting the augmented cycle switching system model about a working equalization point to obtain a system state space equation of the DC/DC converter system suitable for a discontinuous control index stability judgmentbasis; and analyzing the system state space equation according to a preset parasitic parameter and a judgment basis to obtain an index stability analysis result of the DC/DC converter system. According to the index stability analysis method and system for the DC/DC converter provided by the invention, the index stability analysis result of the DC/DC converter system can be accurately obtained without approximation.