30results about How to "Achieve precise tracking control" patented technology

The invention relates to a three-dimensional elliptical vibration cutting device, belonging to the field of cutting and ultra-precision cutting machining of materials which are difficult to machine. A diamond cutter is guided through flexible hinge mechanisms respectively along an X direction, a Y direction and a Z direction, and further, is driven by three piezoelectric stacks respectively alongthe X direction, the Y direction and the Z direction; the piezoelectric stacks of the X direction and the Z direction are preloaded by preloading screw bolts along respective axial direction; the piezoelectric stack of the Y direction is preloaded through a screw bolt screwing wedge; the preloading processes of the three directions are mutually independent; through regulating and matching the initial phase position and the amplitude of a driving signal for each of the three piezoelectric stacks, the projections of the cutter location point movements of the diamond cutter in an X-Y plane and aY-Z plane are elliptical motions, and the projection of the cutter location point movements of the diamond cutter in an X-Z plane is reciprocating elliptical motion or linear motion. The three-dimensional elliptical vibration cutting device has a novel and simple structure, is easy to implement, and is beneficial to obtaining the best cutting machinability of the diamond cutter.

The invention provides an underactuated UUV plane trajectory tracking control method based on dynamic speed adjustment, relating to the motion control technology of an underactuated underwater unmanned vehicle. The invention aims to realize the precise tracking control of an underactuated UUV plane trajectory. The method comprises the steps of (1) a UUV obtains position and attitude information according to a current task, (2) position and attitude error variables are obtained by using the mathematical model of an underactuated UUV, (3) a method of defining a virtual speed error variable to calculate a virtual control rule, (4) combined with a biologically inspired model, the dynamic adjustment of a speed error is carried out, and (5) the control signal generated by a speed adjustment controller is deduced, and the underactuated UUV plane trajectory tracking control is realized. According to the method, the dynamic adjustment of the speed of the underactuated UUV can be carried out, a singular value when a first direction angle error is equal to 90 degrees in a traditional backstepping method is avoided, and the tracking of a circular trajectory in an external constant disturbance is realized.

The invention provides an under-actuated AUV (autonomous underwater vehicle) three-dimensional trajectory tracking control method based on biological speed regulation. The method comprises the following steps: (1) giving expected trajectory position information by an AUV according to the current task, and obtaining current position and attitude information; (2) obtaining position and attitude error variables by use of the mathematical model of an under-actuated UUV (unmanned underwater vehicle); (3) calculating a virtual control law by a method of defining a virtual speed error variable; (4) finishing dynamic regulation of the speed error through a biological inspiration model; and (5) deducing a dynamic speed regulation controller. In the method provided by the invention, the speed error of the under-actuated AUV can be dynamically regulated, the performance of the controller is improved while the singular value of the traditional back-stepping method occurring when the heading angle error is 90 degrees is avoided, and accurate tracking of a time-varying three-dimensional trajectory is realized under external constant disturbance.

The invention provides a UUV trajectory tracking control method for preventing the differential explosion based on the differential output characteristics of a biological instructive model. The method comprises the following steps of 1, conducting the initialization; 2, obtaining position and attitude error variables based on an under-actuated UUV mathematical model; 3, calculating a virtual control law, and replacing a virtual expectancy control law with the output value of the biological instructive model; 4, constructing a Lyapunov function, and transferring the ballast of a position error to the ballast of a speed error, avoiding the differential explosion phenomenon through the real-time derivation of replacing a virtual control variable with the output of the biological instructive model, and realizing the ballast of the speed error; and 5, designing a trajectory tracking controller. According to the technical scheme of the invention, the differential explosion phenomenon caused by the repeated derivation of the traditional back-stepping method can be avoided, and the complexity of the controller is simplified. Meanwhile, in combination with the controller of the biological instructive model, the time constraint requirements of the thrust constraints and the under-actuated UUV trajectory tracking of a propeller on position, speed and attitude can be met.

An adaptive control method for a robotic arm servo system based on a time-varying asymmetric obstacle Lyapunov function comprises the following steps of step 1, establishing a mathematical model of the robotic arm servo system, and designing the time-varying asymmetric obstacle Lyapunov function; step 2, designing an adaptive controller by using the time-varying asymmetric obstacle Lyapunov function and combining an inversion method; and step 3, analyzing stability. By setting the parameter value of a constraint boundary function, the adaptive control method provided by the invention can effectively solve the system output constraint problem and ensure the steady-state performance and transient performance of the system. In addition, the uncertain part of a neural network approximation model and the derivative of the virtual control quantity are used to effectively simplify the design of the controller, improve the robustness of the system to a certain extent, and enable the robotic arm servo system to achieve accurate and fast tracking control.

The invention relates to a robot arm system preset performance control method based on a neural network. The robot arm system preset performance control method based on the neural network comprises the following steps of: S1, establishing a mathematical model of a robot arm servo system, and designing a tangential barrier Lyapunov function; S2, designing a preset performance adaptive controller bycombining the tangential barrier Lyapunov function with an inversion method; and S3, carrying out stability analysis. According to the robot arm system preset performance control method based on theneural network, by setting parameter values of a constraint boundary function, steady-state performance and transient-state performance of the system can be ensured. Moreover, the neural network is utilized to approach an uncertain part of the model and a derivative of a virtual control quantity, so that design of the controller is effectively simplified, robustness of the system is improved to acertain degree, and the robot arm servo system can implement accurate and rapid tracking control.

The present invention relates to an unmanned helicopter heading compensation route transition method. During the deflection process of an unmanned helicopter, a transverse path adopts lateral zero speed maintaining control; a heading path adopts yaw angle rate maintaining control; a yaw angle rate instruction is generated according to heading deviation containing a heading compensation quantity; the heading compensation quantity is determined according to real-time side deviation, a yaw angle rate upper limit corresponding to a current flight speed and a heading compensation quantity threshold, so that a yaw angle speed instruction and a roll angle instruction are obtained; and therefore, when the unmanned helicopter rotates too quickly when swerving due to disturbance, a heading compensation mechanism enables a compensation effect for reducing the speed of rotation; and when the helicopter rotates too slowly when swerving due to disturbance, the heading compensation mechanism continuously gives out heading compensation instructions, and the helicopter continues to complete swerving until the heading deviation and side deviation of the helicopter meet requirements. The heading of the helicopter is corrected through the side deviation, so that the unmanned helicopter can accurately track a target route and achieve precise tracking and control of the route.

The invention relates to a navigation control technology for a cableless autonomous underwater vehicle (AUV). A control method comprises the following steps of: calculating a distance deltaS between the current position of the underwater vehicle and a planned path; substituting the distance deltaS into a PID (Proportion Integration Differentiation) algorithm to obtain control quantity deltaS control of a navigation path offset; calculating navigation control quantity deltaH control of the underwater vehicle reaching a target point; and distributing the sum of the control quantity deltaS control and the navigation control quantity deltaH control serving as a total control quantity to each propeller motor according to the propeller arrangement situation of the underwater vehicle to realize track control over the underwater vehicle. According to the method, accurate track control over the cableless AUV can be realized under an ocean current situation, the distance between the practical track of the AUV and the planned path can be controlled within two meters during stable navigation, and navigation guarantee is provided for accurate completion of a track tracking task by the cableless AUV.

The invention discloses a gas path optimal control system of an electric assisted turbocharged diesel engine, and belongs to the technical field of diesel engine electric control. The gas path optimalcontrol system of the electric assisted turbocharged diesel engine aims at multiple executers and multiple control targets of an electric assisted turbocharged system and is provided with constraintdifficulty. An oil path sensor module, a gas path sensor module and an oil path controller module are set up, a lower-layer NMPC based gas path tracking controller is designed by facing a three-ordermodel of a gas path of the e electric assisted turbocharged diesel engine of multi-target gas path tracking control, and then an upper-layer optimal controller is designed. According to the multi-target requirements of the electric assisted turbocharged gas path control system, precise tracking control of the multi-gas-path state and optimal management of energy transmission in the system are achieved, and therefore the comprehensive performance of the electric assisted turbocharged diesel engine is improved.

The invention discloses a hypersonic aircraft guaranteed-performance fault-tolerant control method considering faults of an executing mechanism, relates to the field of flight vehicle control, and mainly solves the problem of accurate tracking control of a given height/speed instruction under a limited fault condition of a hypersonic flight vehicle. The method comprises the following steps: constructing a novel preset performance mechanism based on a Korean tracking differentiator to realize priori adjustment of errors, and overcoming the problem of transient buffeting caused by rapid constraint of traditional preset performance control; designing a minimum parameter learning (MLP) neural network learner with low computational complexity to eliminate the influence of lumped disturbance onthe AHV model in real time; finally, integrating the MLP observer and a novel preset performance mechanism, and achieving accurate tracking control over a given height/speed instruction under the limited fault condition. According to the method, the MLP observer and a novel preset performance mechanism are integrated, and the method is of great significance in realizing accurate tracking control of a given height/speed instruction under a limited fault condition.