192results about How to "Reduce chattering" patented technology

The invention belongs to the field of autonomous flight control research of small-scale rotary wing type unmanned aerial vehicles, and provides a control method for an unmanned helicopter. The control method achieves rapid and accurate stabilization control over the unmanned helicopter, and has the good robustness for system uncertainty. According to the adopted technical scheme, the control method for a neural network and a nonlinear continuous unmanned helicopter attitude comprises the steps of firstly, analyzing a dynamic model of the small-scale unmanned helicopter, and giving the following rigid body dynamics model which is shown in formula in the specification; secondly, controlling the unmanned helicopter attitude to obtain the following closed-loop system which is shown in the formula of the specification. The control method is mainly applied to design and manufacturing of the small-scale rotary wing type unmanned aerial vehicles.

The invention provides a method for achieving tooth space compensation for a flexible joint of a space manipulator. The method comprises the following steps that the position command signals yd of a direct current motor and the position signals y output by a kinetic model, with space influences taken into consideration, of the flexible joint of the space manipulator are collected, a sliding mode variable structure controller is designed, and a sliding-mode control law is obtained; the control input of a control system of the flexible joint after linear decoupling processing is carried out is obtained by adopting a differential geometry feedback linearization method according to the sliding-mode control law; according to the control input of the control system of the flexible joint after linear decoupling processing is carried out, a disturbance observer is designed for the kinetic model, with the space influences taken into consideration, of the flexible joint of the space manipulator, the control input, under compensation space nonlinear influences, of the flexible joint, and therefore it is guaranteed that the position output of the control system tracks the expected position signals with needed precision. According to the technical scheme of the method for achieving the tooth space compensation for the flexible joint of the space manipulator, influences of the space on the system position precision can be compensated for effectively, high-precision tracking control can be achieved, and the happening frequency of the buffeting phenomenon is reduced at the same time.

The invention discloses an inversing global SMFC (sliding mode fuzzy control) method for a micro-gyroscope based on a neural network. An inversing global SMFC system based on the neural network consists of an inversing global sliding mode fuzzy controller, a neural network dynamic characteristic estimator, and a fuzzy uncertainty estimator. Global sliding-mode control can iron out a defect that an arrival mode in the conventional sliding-mode control does not have robustness, speeds up system response, and enables a system to have robustness in the whole process of response. The method enables a lyapunov function of the system and the design process of a controller to be systematic and structuralized through inverse design during the inversing control. Fuzzy control is used for approximating a switching function term, and a switching term in sliding-mode control is converted into continuous fuzzy control output, thereby weakening vibration in sliding-mode control, and achieving a stronger capability of adaptive tracking. Therefore, the method improves the transient performance and robustness of a sliding-mode control system, estimates the unknown dynamic characteristics of the micro-gyroscope, and reduces the vibration in the control of a sliding-mode control structure.

The invention discloses a permanent magnet synchronous motor predicted current control method and system based on FOSMC; the method comprises the following steps of carrying out comparing on the rotorangular speed and a given rotating speed to obtain a rotating speed difference, and inputting the rotating speed difference into a fractional order sliding mode controller; next, enabling an equivalent current of a dq axis at the current moment to pass through a sliding mode disturbance observer to obtain a voltage compensation quantity and a current estimation value under the parameter change, and enabling the current estimation value and the reference current at the next moment to be input into a non-differential-beat current prediction controller; and finally, carrying out compensating onthe obtained voltage vector and the voltage compensation amount of the dq axis at the current moment, carrying out coordinate transformation, space vector modulation and inversion, and obtaining a three-phase voltage to the permanent magnet synchronous motor, so that the stable operation of the motor is ensured. According to the method and the system disclosed by the invention, fractional order calculus and sliding mode variable structure control are combined, the fractional order calculus has more freedom degree, and the shaking of the system in the sliding mode process can be weakened, so that the control precision of the rotating speed is improved.

The invention belongs to the field of autonomous flight control research of mini-type rotary wing type unmanned aerial vehicles and discloses a method for nonlinear control over an unmanned helicopter posture and a verification platform. An unmanned helicopter is rapidly, accurately and stably controlled. Dependence on prior knowledge of a model by a controller is low and in terms of the uncertainty, the robustness of the system is good. According to the technical scheme, the method for nonlinear control over the unmanned helicopter posture comprises the following steps that firstly, experimental modeling is conducted through a sweep frequency method and a following dynamic model is given; secondly, an unmanned helicopter system is identified; thirdly, the unmanned helicopter posture is controlled. The method is mainly used for controlling autonomous flight of the mini-type rotary wing type unmanned aerial vehicle.

The invention discloses an UUV four degree-of-freedom dynamic positioning adaptive anti-interference sliding mode control system and a control method. The system comprises a first differentiator, a second differentiator, an adaptive anti-interference sliding mode controller, a filter and data fusion unit, a Doppler sensor, an electric gyrocompass, a thrust allocation unit, an UUV, an accelerometer and a gyroscope , wherein the adaptive anti-interference sliding mode controller comprises a sliding mode controller, an adaptive disturbance compensation controller and a data processing unit; the sliding mode controller is used for realizing UUV four degree-of-freedom dynamic positioning variable structure control and eliminating pose errors; and the adaptive disturbance compensation controller is used for estimating uncertainty errors of an actually controlled object model and wave disturbance effects in an online mode. A dynamic process during which the system state approaches to the sliding mode surface is improved, steady-state anti-interference performance is improved, and compared with a common sliding mode control method, dynamic performance is better, and buffet of the system under disturbance effects can be reduced.

The invention discloses a fractional order sliding mode control method of a flexible joint mechanical arm. To overcome buffeting and problems on trace tracking control about integral order sliding mode dynamics control of flexibility of a mechanism arm, the method is as follows: through advantages of sliding mode variable structure control, a fractional order calculus theory is introduced, and a novel fractional order sliding mode variable structure controller high in robustness and interference resistance and having a better buffeting weakening effect is provided by means of quick convergence, information memory and heredity of fractional order differential operators, so a joint flexibility dynamics control system of the mechanical arm exhibits better continuity, rapidity, robustness andgood interference resistance. Finally, the design of a fractional order sliding mode variable structure control method is realized.

The invention discloses an enhanced-type double-power reaching law sliding-mode control method for a four-rotor-wing unmanned plane system. The enhanced-type double-power reaching law sliding-mode control method is designed for the four-rotor-wing unmanned plane system through combining with a double-power reaching law sliding-mode control method. The design of an enhanced-type double-power reaching law aims at guaranteeing that the sliding mode of the system can reach a sliding mode plane more quickly while the vibration of the system is not increased, thereby achieving the quick and stable control of the system.

The invention belongs to the field of flight control of a small-scale single-rotor unmanned helicopter and aims to realize finite-time convergence for unmanned helicopter attitude tracking control. Therefore, the technical scheme is that a nonlinear robust control method with the finite-time convergence capacity for an unmanned helicopter attitude error comprises the following steps: 1, a small-scale unmanned helicopter dynamic model is determined; 2, small-scale unmanned helicopter attitude control is defined as follows: eta d(t)=[phi d(t), theta d(t), psi d(t)]<T>, wherein T is a given reference vector of an attitude angle, phi d(t), theta d(t) and psi d(t) are a given roll angle, a given pitch angle and a given yaw angle, and the relationship and relevant parameters are shown in the specification. For writing convenience, the variables do not carry the time t, and for example, eta d(t) is directly written as eta d; the attitude tracking error is defined as follows: e= eta d-eta. The method mainly applies to flight control of the small-scale single-rotor unmanned helicopter.

The invention discloses a rotating-speed-estimation-based self-adaptive fuzzy and sliding-mode control method of an ESC, and belongs to the field of automobile hydraulic power assisted steering systems. The control method includes the following steps: 1, an outer rotor of the ESC is connected with an engine, an inner rotor of the ESC is connected with a steering pump, and an ESC type electronic control hydraulic steering system is built; 2, a rotating speed signal of the steering pump in the ESC type electric control hydraulic steering system is collected through an ECU; 3, an ESC dynamic equation is built based on the rotating speed in the step 2, wherein a mathematical model of the ESC under the d-q axis is built; and 4, based on the mathematical model in the step 3, a rotating-speed-estimation-based self-adaptive fuzzy and sliding-mode controller is designed. According to the rotating-speed-estimation-based self-adaptive fuzzy and sliding-mode control method, the beneficial effects of self-adaptive fuzzy control and fuzzy sliding-mode control are adopted, satisfied system responses are generated through a dynamic self-adaptive law, interference is obviously eliminated, and buffeting is reduced.

The invention discloses a finite time integral sliding mode terminal guidance law based on a super-twisting algorithm. The guidance law comprises the following steps: step 1, establishing a three-dimensional target-missile relative motion equation; step 2, designing a guidance law. A stability analysis is conducted on the guidance law. The invention provide the finite time integral sliding mode terminal guidance law based on the super-twisting algorithm by combining an integral sliding mode, a super-twisting algorithm and a finite time disturbance observer. According to the finite time integral sliding mode terminal guidance law based on the super-twisting algorithm, the finite time can be converged, the buffeting phenomenon can be eliminated, so that the maneuvering acceleration of a target can be better estimated, and the guidance accuracy is high; and the guidance law can be used for intercepting high-speed large-maneuvering targets such as unmanned aerial vehicles, ballistic missiles and the like, and has a wide application prospect.

The invention discloses a multi-motor servo system active disturbance rejection sliding mode speed control method based on inertia identification. The method comprises the steps that: a kinetic equation of a multi-motor servo system is constructed; the load inertia input by the multi-motor servo system is identified by using a model reference adaptive method; a first-order active disturbance rejection model is constructed according to disturbance in a first-order tracking differentiator, a second-order extended state observer and a multi-motor servo system speed loop to obtain a nonlinear state error feedback control law; and a reaching law is improved based on a hyperbolic tangent softening switching function, sliding mode control with integration is constructed to compensate and optimizethe nonlinear state error feedback control law, a final control law is obtained, and then active disturbance rejection sliding mode speed control of the multi-motor servo system is achieved. Comparedwith partition PID control and integral sliding mode control, under the condition of variable inertia, the composite control strategy has better adaptability to the inertia change condition, a bettercontrol effect can be obtained, and the robustness of the control system is high.

The invention relates to a self-adaptive finite time convergence sliding-mode control method of a robot and belongs to the technical field of control. The method comprises steps as follows: establishing a robot kinetic equation considering uncertainty, determining a sliding mode surface, then introducing n-dimensional self-adaptive updating rate, calculating value of active power/moment required for driving the robot finally, and driving a robot system based on the value so as to enable generalized coordinate vectors of the robot to converge to a steady-state or trace command signals in finite time. The method has the characteristics and benefits as follows: firstly, the problem of chattering of the sliding-mode control is solved greatly while high-precision control is realized; secondly, possible influence of different dynamic characteristics in all directions of freedom degrees of the robot system can be eliminated; thirdly, the problem of moment saturation and chattering of the robot system at the starting stage can be solved; fourthly, kinetic compensation guaranteeing real-time performance of the control can be realized. The method is applicable to the robot systems with structure types of parallel connection, series connection, series-parallel connection and the like.

The invention claims to protect an integral sliding mode control method of a permanent magnet synchronous motor speed regulating system based on interference compensation, Firstly, the speed controller based on integral sliding mode is designed according to the mathematical model of permanent magnet synchronous motor (PMSM). Secondly, a generalized proportional-integral observer (GPIO) is designedfor disturbance compensation. Finally, a hybrid speed controller is designed by using the speed controller and the disturbance estimate. Compared with the uncompensated integral sliding mode controlmethod, this method can compensate the disturbance to restrain the disturbance, has small fluctuation amplitude, fast speed regulation and good tracking effect, and can meet the application requirements of high-performance permanent magnet synchronous motor speed control system.

The invention discloses a sensorless control method for a permanent magnet synchronous motor based on a sliding mode observer, which specifically comprises the following steps: firstly, according to amathematical model of a surface-mount permanent magnet synchronous motor in a two-phase stationary coordinate system, using an observation error of stator current as a sliding mode surface to write asliding mode current observer equation; then, carrying out the stability analysis of the sliding mode current observer equation; based on the sliding mode current observer, constructing a back electromotive force observer equation on the basis of a back electromotive force model for separating a back electromotive force signal and then estimating the rotor position and rotational speed, and carrying out the stability analysis of the back electromotive force observer equation; secondly, based on the sliding mode current observer, identifying the stator resistance of the motor; and finally, adjusting the feedback gain in real time according to the running speed of the motor. The sensorless control method for the permanent magnet synchronous motor based on the sliding mode observer in the invention solves the problem that the chattering phenomenon of the observation signal in the sliding mode observer existing in the prior art is big, low-pass filtering and rotor angle compensation are required, and the observation precision is not high.

An indirect adaptive fuzzy sliding mode control method of a SISO discrete time system is disclosed. The method comprises the following steps: step 1. selecting an offline parameter; step 2. constructing a sliding mode controller with a fuzzy subsystem; step 3. performing online adjustment to a parameter vector of a fuzzy system and calculating control input. An adaptive law with parameter projection is used to on-line adjust the parameter vector of the fuzzy system. According to the invention, through introducing the sliding mode control, system uncertainty, an adverse effect of unknown external interference on system stability and dynamic performance can be overcome. Through introducing a unknown function and switching control in the fuzzy system approximation sliding mode control law of the parameter vector adaption adjustment, dependence of a control method to a system prior model can be eliminated, flutter caused by the switching control can be mitigated and even completely eliminated and precision for system output to track a given track can be increased. By using the method of the invention, the system stability and the dynamic performance can be simultaneously considered and practical value is possessed.

The invention discloses a neural network based inversion global sliding mode fuzzy control method for an active power filter. A neural network based inversion global sliding mode fuzzy control system is composed of an inversion PID global sliding mode controller, a neural network dynamic property estimator and a fuzzy uncertainty approximator. Global sliding mode control can overcome shortcomings of robustness insufficiency of an arrival mode in traditional sliding mode control and accelerates system response so as to enable the system to have robustness in the whole process of response. Due to approximation of switch function items by adopting fuzzy control, switch items of sliding mode control are converted to continuous fuzzy control output, so that chattering in sliding mode control is relieved and comparatively high self-adaptive tracking capability is achieved. Therefore, through combination of inversion PID global sliding mode control and neural network fuzzy control, advantages of inversion PID global sliding mode control and neural network fuzzy control can be fully played, transient performance and robustness of the sliding mode control system can be improved and chattering in variable structure control is reduced.

The invention discloses a turning method of a thin-wall vane of a leaf disc type part, which comprises the following steps: a polyurethane foaming agent is filled in each flow channel of an impeller, i.e. a gap between two vanes; after the polyurethane foaming agent is solidified, the impeller is positioned and clamped by a special fixture, and the periphery molded surface of the vane is turned after the impeller is aligned by a lathe; and after turning is completed, the polyurethane foaming agent is eliminated by cutting or sanding. Because the polyurethane foaming agent adopted in the method has certain strength after being filled, no adverse effect is caused to the leaf disc type part, and the cutting is easy. Filling the polyurethane foaming agent between the two vanes is equivalent to supporting the vanes, so the rigidity of each vane in turning is effectively enhanced, the discontinuity of turning is simultaneously improved, and chattering and deformation in processing are relieved so as to improve the processing accuracy of the periphery molded surface of a vane of a semi-open impeller, particularly a three-dimensional impeller with a wide and deep flow channel.

The invention discloses a finish-milling feeding speed optimizing method based on integral impeller blade shape. The method comprises the steps of generating a finish-machining cutter track source file of a spherical head cutter blade with the radius as RT and based on a spherical head according to a geometrical shape of an integral impeller blade, introducing a single impeller blade model, judging the cross line between a runner and the blade according to the distance between a point on the blade and the center of an impeller, extracting the cross line, discreting the cross line into W points according to equal chord heights, composing a point set U through W points, setting the longitudinal depth acceleration proportion omega between the top end of the blade and the tail end of the blade, sequentially reading and analyzing the cutter track source file generated in the step 1 line by line, and extracting cutter point information of all cutting paths in the cutter track source file generated in the step 1. In addition, the cutter track source file records cutter point coordinates under a processing coordinate system and cutter axis vectors corresponding to the cutter point coordinates. The finish-milling feeding speed optimizing method solves the technical problems that an existing method is low in processing efficiency, poor in processing quality and serious in cutter abrasion.

A centrifugal clutch is disclosed, which comprises a drive unit, a friction unit and an assistant unit. The drive unit comprises a base disc and a drive disc. The friction unit comprises a plurality of shaft rods, a plurality of centrifugal counter weights pivoted on each shaft rod, a plurality of friction pieces disposed on each centrifugal counter weight, a plurality of elastic elements connecting the two adjacent centrifugal counter weights, and an outer cover surrounding the friction pieces. The assistant unit comprises a plurality of location pins, a plurality of drive pins, a plurality of linkage pieces sleeved on the location pins and the drive pins, and a location ring disposed on the drive disc. An acting force on each centrifugal counter weight is increased, and the friction force between each centrifugal counter weight and the outer cover is increased by the drive pins, the linkage pieces and the location pins, thereby efficiently avoiding a slip as well as reducing friction heat and vibration.