38results about How to "Reduce contour error" patented technology

The invention discloses a contour control method of a complex track. The invention is combined with a cross-coupling control framework with contour error pre-compensation function, establishes adaptive data models for the axles participating in the servo movement, determines the identification parameters of the controlled servo objects according to the current target position points and a plurality of historical position point values, and real-timely sets the control parameters with a pole placement algorithm. The method which adjusts the controlled output on the basis of a historical control output and a future control output effectively curbs bounded process interference and improves the accuracy of the contour control and the stability of the process.

The invention discloses a control method for motion stability and outline machining precision of a multi-shaft linkage numerical control system. The control method achieves control on the motion stability and outline machining errors of the multi-shaft linkage numerical control system by using a compound control mode of multi-shaft parameter module predictive control and non-linear self-adaptive fuzzy proportional-integral-derivative (PID) control. Simultaneously, error module calculating efficiency is improved by building an outline error module, a speed error module and an acceleration error module. By means of performance optimization indexes, tracking errors, outline errors, speed errors and acceleration errors of the system are minimum, and control performance of a multi-shaft servo control system is improved. Multi-shaft parameter module predicative control increment is solved through a simplified calculating module so as to meet real-time requirements of the control system. Robust property of the multi-shaft linkage numerical control system is improved by adopting the non-linear self-adaptive fuzzy PID control method. The control method effectively improves the motion stability and outline machining precision of the multi-shaft linkage numerical control system.

The invention discloses a contour error cross-coupling control method based on interference observation sliding mode variable structure. The method provides a control strategy combining sliding mode variable structure control, a disturbance observer and cross-coupling control and comprises steps of: designing a single-axis servo sliding mode variable structure controller based on disturbance observation; performing stability analysis on a sliding mode variable structure control algorithm based on disturbance observation; designing a cross-coupling controller based on a PID control algorithm; and performing result simulation and analysis. The sliding mode variable structure control based on disturbance observation can eliminate the influence of disturbance, enhancs system robustness and achieves accurate tracking of single-axis motion. The cross-coupling control is configured to eliminate the influence of gain parameters and dynamic mismatch between axes, reduces the contour error to achieve multi-axis coordinated motion. Finally, the effectiveness and superiority of the control method are proved by a two-axis system simulation model, and the tracking error and contour error are effectively compensated.

The invention relates to a servo system contour control method, in particular to a servo system contour control method based on a task polar coordinate system. The servo system contour control method based on the task polar coordinate system comprises the first step of establishing an XY motion platform kinetic equation, the second step of establishing the task polar coordinate system based on osculating circle proximity according to expected track information and calculating the corresponding coordinate transformation relation, the third step of converting a system kinetic equation under a Cartesian coordinate system into an error kinetic equation under a task polar coordinate, and the fourth step of designing a feedback PD controller based on the feedforward compensation and achieving the decoupling control on the error kinetics. The decoupling contour control method based on the task polar coordinate system has the advantage that the contour error caused during the high-speed and large-curvature contour machining process can be greatly reduced.

The invention belongs to the field of robot milling machining and discloses a milling machining robot attitude optimizing method and device considering the minimum contour error. The method comprisesthe following steps that S1, the cutting force simulation of a cutting process is carried out according to a to-be-machined workpiece and the path of a cutter, and cutting force data at a discrete cutter location point are obtained; S2, the cutter location point data under a workpiece coordinate system are converted into the cutter location point data under the robot base coordinate system; S3, equal interval division is carried out on all cutter location points within the feasible range of the cutter shaft angles; S4, the nose point deviation at each cutter shaft angle is calculated; S5, thecutter location point contour error of the cutter milling machining is calculated; S6, for a single cutter location point, the robot attitude corresponding to the minimum cutter location point contourerror in all the cutter shaft angles is searched for under a given limit and constraint condition, and the robot attitude with the minimum cutter location point contour error is obtained; and S7, thesixth step is carried out on all the cutter location points, and the milling machining robot attitude with the minimum contour error is obtained.

The invention discloses a control algorithm for a contour error of a servo system. A single-axis sliding mode tracking controller, a fuzzy controller and a two-axis cross-coupling controller are designed according to steps. The single-axis motion control uses a fuzzy-based sliding mode control algorithm and the interference is eliminated by using switching gain of the sliding mode control. On thebasis of the single-axis sliding mode control, the fuzzy controller is introduced and the switching gain of the sliding mode control is adjusted by the continuous output of the fuzzy controller; and the upper bound of the disturbance is estimated by the integral method, so that the advantage of the high robustness of the system uncertainty and external disturbance by the sliding mode control is kept and the system buffeting is eliminated effectively. On the basis of the cross-coupling control algorithm, problems that the gains between the two axes is not matched and the external unbalanced disturbance is high are solved; and the correction amounts of all axes are compensated in real time by variable gains; the e overall contour error of the system is reduced effectively; and the two-axis linkage control is realized.

The invention relates to a method for improving machining accuracy of internal honing wheel strong gear honing. The method comprises the following steps that 1, according to an internal honing wheel strong gear honing technology of a machined gear, the gear honing process parameters influencing the gear machining accuracy are extracted, the gear honing process parameter combination is designed, the gear honing machining experiment is conducted, and the tooth surface outline error indexes of the machined gear are obtained; 2, according to the gear honing process parameter combination and the tooth surface outline error indexes of the machined gear, the mathematical model of the tooth surface outline error is constructed through the response surface nonlinear fitting method; 3, on the basis of the anticipated machining precision value corresponding to each tooth surface outline error index, the weight ratio is applied to each tooth surface outline error model, and the tooth surface comprehensive outline error mathematical model is constructed; and 4, based on the artificial immune clone selection algorithm, the gear honing process parameters are optimized, and the optimal honing process parameters are obtained. According to the method, the machining accuracy of the internal honing wheel strong gear honing is improved, and the theoretical basis is provided for the practical selection of the internal honing wheel strong gear honing process parameters and the improvement of the gear precision.

The invention discloses a finite control set model predictive contour control method suitable for a double-axial or tri-axial feed driving system. On the basis of unified modelling, unified control architecture of the double-axial or tri-axial feed driving system for finite control set model predictive control is provided; output information of various axes are interacted; furthermore, various axis loop controllers are integrated; simultaneously, under the control architecture, a compact non-cascade predictive controller is designed; a unified value function is established by taking the contour error, the running performance of a motor and the current amplitude limitation as evaluation indexes; and thus, multi-variable cooperative optimization control is realized. Different from the traditional contour control strategy, a finite control set model predictive control strategy can perform predictive control before the contour error occurs; furthermore, the dynamic response speed and the contour precision at the position of a trajectory turning point can be increased; and simultaneously, the method in the invention has the advantages of being intuitional to model, simple in structure and the like.

The embodiment of the invention discloses a method for estimating the reversely calculated control points of an NURBS. The method is characterized by comprising the following steps of 100, simplifyingthe cutter location points through the known cutter location points and a set error threshold, and selecting the cutter location points representing a typical contour; 200, taking the simplified cutter location points as the control initial values, and calculating the control points required for interpolating the cutter location points; 300, fitting the NURBS by taking the calculated control points as the fitting initial values, and calculating a contour error after fitting; 400, comparing the contour error after each time of calculation with the error threshold value, increasing or decreasing the control points according to a comparison result, and repeating the steps 200 to 400 until the minimum control points meet the error threshold value. According to the method, the defects of a traditional mode are overcome, the more accurate control points are estimated according to the known contour threshold value, and on the basis, the needed control points are calculated through multiple iterations, so that the reversely calculation efficiency of the NURBS can be greatly improved.

The invention discloses a curve cross coupling contour error compensation adjustment control system, which comprises a numerical control PC, a curve cross coupling contour error compensation adjustment motion control card, a driver, a servo motor module, and a position feedback and detection module. The numerical control PC comprises a numerical control PC body, a display and a PCI interface chip, wherein one end of the numerical control PC is connected with the display to realize man-machine conversation, and the other end is connected with the curve cross coupling contour error compensation adjustment motion control card through the PCI interface chip, so as to realize compensation of curve cross coupling contour errors. Meanwhile, the invention further discloses a control method for curve cross coupling contour error compensation. The curve contour error compensation adjustment control system and the error compensation method have the advantages of high regulation and control efficiency, good stability, high practicality and the like, realizes cross coupling compensation of curve contour errors; and the contour error compensation adjustment control method can greatly reduces contour errors, improves interpolation control precision, and can produce good economic and social benefits.

The invention discloses a crystal grinding control method and system based on closed-loop cross coupling iterative learning. The method comprises the following steps: S10, establishing a mathematicalmodel of a crystal grinding servo system; S20, establishing a discrete closed-loop cross coupling iterative learning controller to control the position; S30, generating a new control signal by a discrete closed-loop iterative learning controller; S40, acquiring a new tracking error according to the expected position information and the actual information by the controller; and S50, compensating each shaft through a contour error distribution model to eliminate the influence of each shaft on other shafts.

The invention discloses an optimization control method and system for the acceleration and deceleration motion of an industrial manipulator, wherein the method for optimizing the acceleration and deceleration motion of an industrial manipulator comprises: acquiring kinematic parameters and a processing path of the industrial manipulator, and obtaining the kinematic parameters and processing path of the industrial manipulator, and obtaining the kinematic parameters of the industrial manipulator through the kinematic parameters. Build an acceleration and deceleration control model; process the machining path into micro-segments and obtain the mutation point in the machining path, and set constraints according to the kinematic parameters and the geometric features of the machining path; calculate the speed of the mutation point through the constraint conditions Planning, generating the maximum running speed of the industrial manipulator at the locus of the trajectory; sending the maximum running speed to the interpolation module, and realizing the error compensation of the error acceleration and deceleration movement through the interpolation module. The invention ensures the continuous operation of the industrial manipulator by planning the speed of the turning point in the processing path, and simultaneously improves the control efficiency of the acceleration and deceleration movement.

The invention discloses a processing track local fairing method for synchronous design of geometric fairing and speed planning. The processing track local fairing method comprises the following steps: 1, acquiring a fairing length upper limit value of a fairing curve; 2, calculating a reachable speed value according to the fairing length upper limit value obtained in the step 1; 3, calculating the shortest fairing length when the normal constraint is satisfied according to the reachable speed value obtained in the step 2; 4, determining the optimal fairing length according to the fairing length upper limit value obtained in the step 1 and the shortest fairing length calculated in the step 3; 5, according to the optimal fairing length determined in the step 4, carrying out fairing curve and speed planning synchronous design. According to the method, on the premise of geometric constraint, the fairing curve is designed according to the actual reachable speed, so that contour errors are reduced on the premise that the processing efficiency is ensured by a synchronous design strategy. The method has important significance in occasions with important machining efficiency and contour precision.