250 results about "Contour error" patented technology

The invention discloses propeller type surface contour error measurement instrument and method. The propeller type surface contour error measurement instrument is characterized in that a gantry structure is adopted, a left upright, a right upright and a top cross beam are arranged on a base, and a revolving spindle is arranged on a cross beam; the lower end of the revolving spindle is horizontally and fixedly connected with a measuring arm; a linear guiderail is arranged on the bottom surface of the measuring arm along the radial direction of the revolving plane of the measuring arm, a working platform capable of doing linear movement along the linear guiderail is arranged on the linear guiderail, and a displacement sensor is arranged on the working platform; and a Y-direction working platform and an X-direction working platform are arranged on the base in an overlapping, and the blade of a detected propeller is arranged in a positioning groove at the top surface of the X-direction working platform. The measuring device and the measuring method are established by adopting a cylindrical coordinate system according to the axial symmetry structure characteristics of the propeller blade. The measuring device and the measuring method are fast in data acquisition, have no objective errors of an operator, and are simple in follow-up error processing and analysis, and can be used for precision measurement on size parameters and geometric error parameters of large revolving parts.

The invention discloses a digit control machine double-shaft synchronization control device, comprising a clock, an input and output interface, a double-shaft position check module, a control unit, a system parameter list and a pitch compensation list, wherein the double-shaft position check module processes position and synchronization error check for two synchronous shaft motor encoders and provides the check information to the control unit, the control unit selects a working mode corresponding to the parameters of the system parameter list, according to the position and error information of the two synchronous shafts provided with the double-shaft position check module and the process corresponding to the selected working mode, the control on the two synchronous shafts can be realized. The invention resolves the problem of the common digit control system which can not realize synchronous control, realizes the real-time character between transfer and adjustment, avoids the profile error of processed elements caused by delayed transfer time, and avoids the serious dynamic synchronous error caused by long adjustment.

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 provides a parameter curve cutter path oriented numerical control system contour error control method which comprises the following steps of: 1) calculation of the contour error; 2) calculation and control of the contour error compensation quantity, and is characterized in that: in the step 1), in each sampling period for performing curve interpolation on the parameter curve cutter path, the contour error epsilon is calculated according to the current actual cutter location point and the interpolation point on the tracked parameter curve cutter path, namely the shortest distancefrom the current actual cutter location point to the tracked parameter curve cutter path is calculated; in the step 2), the components of the contour error epsilon along the X axis, Y axis and Z axisare calculated, and the contour error compensation quantities are obtained by proportional control and superposed with the location control quantities for the following error on the X axis, Y axis and Z axis respectively; and then the result is output to a servo execution mechanism to perform contour error compensation control. The method provided by the invention has the advantages that: the contour error calculation precision is high, the contour error compensation method is simple and effective, and the contour precision can be obviously improved.

The invention relates to an acceleration and deceleration look-ahead control method for the high-speed machining of a numerical control machine tool. The method comprises the following operation steps of: (1) cutting the curve data of a CAD/CAM (Computer-Aided Design/Computer-Aided Manufacturing) model into a NC (Numerical Control) curve data model according to a contour error; (2) inputting system parameters, such as interpolation cycle T, maximum speed Vmax, and the like, on the basis of a NC code; (3) carrying out microfield integral S-shaped speed planning on the basis of the system parameters and determining the corresponding speed (i is equal to 1:N, N is a look-ahead field number, that is to say, a speed value from the first field to the Nth field is determined) of all fields on a S-shaped speed curve; (4) determining a microfield adapting angle allowed passing speed (i is equal to 1:N); (5) determining a point at which the adapting angle allowed speed is smaller than planned speed; (6) outputting a machining interpolation point; and (7) executing the information and finishing the machining of parts by a motion control system. In the step (5), the reasonable speed at which the microfield machining can be carried out is determined on the basis of comparing the speed on the S-shaped speed curve with the adapting angle allowed passing speed, and thereby, the S-shaped speedcurve with highest efficiency is obtained; and finally, the machining interpolation point is output to the motion control system. According to the method, the machining precision is ensured, the machining efficiency is greatly increased, the flexible impact of the machine tool is effectively prevented and the service life of the machine tool and cutters is prolonged.

The invention belongs to the field of numerical control machine tool dynamic error compensation and relates to a novel contour error estimation method, particularly to a curved surface tool path contour error compensation method based tool location point correction. The method comprises, on the basis of identifying the servo gain of a machining feed shaft control system, estimating practical machining points off line according to a following error model and linear interpolation machining codes; estimating contour error vectors according to a method similar to accumulated chord length parametric cubic spline of ideal tool paths; computing the contour error compensation according to the components of the contour error vectors on every axis to obtain compensated tool location points and further to generate linear interpolation numerical control machining codes for practical machining. The curved surface tool path contour error compensation method based tool location point correction can improve the dynamic precision of a numerical control machine tool and is high in precision, stable in computation, free from online measurement, easy to implement and wide in application range.

The invention discloses a track planning and control method of a free curve of an industrial robot based on double quaternions. Control point data of the Cartesian space are adopted for describing the contour of the space free curve, and meanwhile an Adams differential equation is adopted for NURBS interpolation compacting calculation, and interpolation speed is adjusted in a self-adaption manner with the maximum contour error and maximum acceleration as constraint conditions; and then the position and posture of the robot in the Cartesian space are converted to a four-dimensional space through a short linear segment obtained through interpolation by adopting the double quaternions, the motion trail of the robot is subjected to spherical linear interpolation through hyperspherical rotation, and finally the track of the NURBS free curve of the industrial robot is planned.

The invention discloses an error compensation method of numerical control grinding contour of a camshaft, comprising the following steps: a. performing offline measurement on the contour line of a processed cam sheet by multiple trail cut processing to obtain practical contour line data for respectively lifting; b. calculating the lifting error value of one circle of the whole cam sheet by comparing theory lift and actual measurement lift data, analyzing the lift error, and predicting the error; c. building a virtual lift table, and performing secondary fairing processing to the virtual lift;d. adopting a post-processed virtual lift table to replace an original lift table, and performing numerical control processing of the camshaft which has the same type with a trail cut camshaft under the same technological condition. Based on the above steps, the invention programs and develops the error analysis and compensation processing software of numerical control grinding contour error of acamshaft and realizes the intelligent and automatic application of a technical method; the lift error value of the whole contour line of the processed cam sheet is integrally reduced, molded line precision is obviously improved, no burn or waveness exists on the surface of the contour, surface quality is favorable, and error compensation effect is obvious.

The invention relates to an on-line measurement method for an axis orbit of a main shaft under cutting condition of a numerical control lathe. The on-line measurement method comprises the following steps of arranging three displacement sensors on a to-be-measured circular surface along the circumferential direction of the main shaft, collecting displacement signals and main shaft rotary angle signals before cutting, converting into rotary angle interval sampling signals, adopting a three-point method to separate the contour error of the to-be-measured circular surface, extracting the displacement signals of the two vertical displacement sensors, and calculating the installation eccentric error; according to the contour error and the installation eccentric error, obtaining an interference signal guided by the to-be-measured circular surface; under the cutting condition, adopting an interpolation method to calculate the interference signal corresponding to the main shaft rotary angle signal, removing the interference signal from the displacement signal under the cutting condition, and obtaining the axis orbit of the main shaft. The method has the advantages that the influence on the separation calculation by the speed fluctuation of the main shaft is avoided, the requirements of separation accuracy and rotary error quick separation are met, and the on-line quick separation of the rotary error is realized.

The invention discloses an in-process evaluation based complex spatial surface error feedback compensating method. The method comprises the following steps of processing a complex surface cutting force module through a ball-end cutter, performing dynamic compensation for a target cutter location point for workpiece pre-processing; performing in-process detection for the pre-processed workpiece to obtain geometrical information of an actual contour; evaluating error for the pre-processed workpiece through a contour degree error evaluation model; when the contour error is greater than tolerance, determining a compensation point position U1 corresponding to each contact point; guiding the compensation point position corresponding to each contact point to three-dimensional CAD (Computer-Aided Design) to obtain a compensating process contour to generate a compensating processing tool track; and performing static compensation and processing for the pre-processed workpiece and finishing the flow. Under the premise of ensuring the processing precision of part surface, the processing precision of the part is detected in process without investing fund to purchase more detection devices, so that the conveying and loading time of workpieces is shortened.

The invention provides a direct-driven XY table profile control method based on predictive control and cross coupling, and belongs to the technical field of automatic control. The device comprises a signal collector, a position setter, a predicating controller, a cross coupling controller and a driving device, wherein the cross coupling controller comprises a profile error estimating device and a profile error compensating device. The direct-driven XY table profile control device and method based on predictive control and cross coupling are provided by the invention according to the characteristics of a direct-driven XY platform; the predicating controller is adopted to control a single shaft, so that the tracking error in the system can be reduced, and the precision in positioning of double shafts can be indirectly improved; and the cross coupling controller is adopted on the dual-shaft for decoupling, so that the profile error of the system can be directly compensated, and the precision in processing can be improved.

The invention relates to an auto-disturbance rejection controller-based iterative learning contour error control method for a networked multi-axis motion control system. According to the method, firstly, the uncertainty of the system caused by time-varying delay is dynamically processed as one part of the total disturbance of the system, and the total disturbance of the system is expanded into a new variable. In this way, an augmented model of a networked single-axis servo control system is established. Secondly, an expanded state observer is designed to estimate the state of the augmented system, and then a linear self-disturbance rejection controller based on the expanded state observer is adopted to realize the tracking control of a single-axis trajectory. Thirdly, the contour error model of the system at the current moment is calculated. According to an obtained contour error, a contour error compensation controller based on an iterative learning control algorithm is designed. In this way, the high-precision tracking control on the contour of the system is achieved. The method realizes the good tracking control performance for the single-axis trajectory, and the good anti-disturbance capability for the model uncertainty of the system. The high-precision tracking control performance for the contour of the system is also achieved.

The invention discloses a method for preparing a high-precision arc-blade diamond lathe tool, and the method comprises the steps: firstly fixing the diamond lathe tool on a work bench which can rotate and swing, fixing a CCD camera above the diamond lathe tool; collecting real-time images of the diamond lathe tool to a computer by an image collection card; extracting contour lines of the arc part which needs to be processed and is arranged at the front end of the diamond lathe tool and the edge line parts at two ends for forming a contour line point group; segmenting the point group of the arc part at the front end from the extracted contour line pint group for obtaining an initial arc center of the contour of a cutting blade of the lathe tool, thereby obtaining the contour error of each point on an arc of the contour of the cutting blade of the lathe tool; adjusting the initial arc center of the lathe tool to be coincided with a rotation center of a grinding system and then fixing; driving the lathe tool to rotate and driving a grinding wheel to feed for processing the arc blade of the lathe tool according to the contour error and position information of each point on the arc. The use of the method can realize the stable, high-efficient and high-precision processing of the arc-blade diamond lathe tool.

The invention discloses a machine tool plane contour error monocular measuring method, belongs to the field of computer vision measurement and relates to the contour error measuring method suitable for an ideal motion trail and an actual motion trail of a machine tool plane. The measuring method comprises the steps that a monocular camera and a numerical control machine tool are integrated; a measuring basis with matrix arrangement code mark points is designed at first, and the position relation between every two code mark points is made to be precise and known; the measuring basis and the monocular camera are fixed to the machine tool during measuring, and motion images of the measuring basis are gathered through the monocular camera; and during image processing, the multiple code mark points which are in each frame of the images and close to the centers of the images are identified and positioned, and the motion trail of the machine tool is calculated according to the known position relation between every two code mark points. According to the machine tool plane contour error monocular measuring method, the problems that the plane motion trail range needing to be measured is large and any tails are difficult to measure due to the fact that the stroke of the machine tool is large are solved, and the high-speed motion plane contour error of the machine tool is measured in a wide range and high precision mode, and the measurement precision is effectively improved.

The invention provides a double-linear-motor contour compensation device and method based on a fuzzy RBF network integral sliding mode with respect to a double-linear-motor numerical control feeding system with the axial direction being in mutual vertical movement. A real-time contour error is used as the input of a controller, the powerful self-learning ability of the controller enables the contour error to tend to zero within limited time, and thus contour machining precision is improved. The double-linear-motor contour compensation device comprises a commutating and voltage-stabilizing unit, an IPM inverter, a DSP, a Hall sensor, a grating ruler, a current detection unit, a position and speed detection unit, an optical coupling isolation circuit, a driving protection circuit and a fault detection and protection circuit. The DSP comprises a QEP circuit of an event manager EVA, an ADC module, a PWM unit, a Flash storage module, a program storage, a timer and a PDPINT pin. A PI controller of a position signal setter, a linear motor position loop, a speed loop and an electric current loop, a contour error calculator, a fuzzy RBF network integral sliding mode contour compensator and a driver device are further arranged inside the DSP. The double-linear-motor contour compensation device is good in robustness, suitable for contour machining tasks of any track and capable of achieving high-precision contour control.

An apparatus for detecting an error in a contour of a lesion includes an extracting unit configured to extract a contour of a lesion in each of a plurality of two-dimensional image frames that form a three-dimensional image, and an error determining unit configured to determine a presence or an absence of an error in a contour of a lesion in a target image frame of the two-dimensional image frames based on estimation information about the lesion in the target image frame and/or an energy value that corresponds to the contour of the lesion in the target image frame.

A method for controlling cascade-stage iteration learning cross coupling contour errors of a triaxial numerical control system, comprises the procedures of confirming practical reference input quantity of the triaxial numerical control system, a following error formula of an X axle, a following error formula of a Y axle and a following error formula of Z axle, deducing the convergence conditions for cascade-stage iteration learning control (ILC), obtaining the necessary convergence condition as a formula (2) of the cascade-stage ILC according to a formula (1), and realizing the contour error control of the triaxial numerical control system by getting a iteration learning law and a contour error controller meeting the conditions of the formula (2). The method for controlling the cascade-stage iteration learning cross coupling contour errors of the triaxial numerical control system has excellent dynamic compensation and smooth contour errors and being capable of improving the control performance.

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 belongs to the technical field of precision high-efficiency numerical control machining, and relates to a contour error real-time estimation method based on spatial arc approximation in a spline curve interpolation process. According to the method, a parameter initial value for Newton iteration on a parameter curve is calculated based on a first-order Taylor series expansion method before a perpendicular foot is calculated in each Newton iteration, and then a single iteration parameter final value is calculated according to the parameter initial value by using a Newton iteration method. In order to avoid greatly increasing the calculation time of the algorithm, circulation is ended under double constraints of an iteration terminating precision condition and a maximum iteration number condition to obtain a parameter estimation value of the perpendicular foot, and a contour error vector estimation value is calculated. The method still can effectively guarantee the estimation precision of a contour error when the follow-up error is relatively large, and has great significance for improving the spline curve interpolation machining contour precision of a high-grade numerically-controlled machine tool.

The invention discloses a high-dynamic wide-range any contour error monocular six-dimensional measurement method of a numerical control machine tool, belongs to the field of machine tool dynamic errordetection, and relates to a high-dynamic any wide-range contour error six-dimensional measurement method of a numerical control machine tool. In the high-dynamic any wide-range contour error six-dimensional measurement method, the monocular vision measurement technology cooperates with short-time stroboscopic illumination and a prior standard plate. In the method, a measurement tool and a measurement system are designed, and the monocular vision pose algorithm is combined with priori knowledge to increase the dimensionality and range of the machine tool interpolation contour capable of beingmeasured by vision. Through combination with the error distribution principle, a small measurement view field is utilized for improving the view field measurement precision of coding elements; the method is adopted for carrying out traversal shooting on each frame of image, and the actual six-dimensional motion contour of the machine tool can be obtained; and through comparison with the nominal motion contour of the machine tool, six-dimensional errors generated by the interpolation contour of the numerical control machine tool can be resolved. By means of the method, the monocular vision posealgorithm is combined with a datum conversion method, and the dimensionality of the machine tool interpolation contour measured by vision is improved; and wide-range any contour error six-dimensionalmeasurement of the numerical control machine tool in the small view field is achieved.

The invention discloses a real-time self-adaptive contour error estimation method, which can be used for a numerical control system or a contour controller of a robot. The contour error estimation method comprises the steps: generating extra interpolation points by properly modifying a conventional parameter curve interpolation method, wherein the generated extra interpolation points are only used for contour error estimation and do not serve as reference instructions of a motion controller; searching among original interpolation points the nearest point from an actual cutter position, preliminarily determining a search scope; and further determining foot points through a binary search method. A distance between the foot points and an actual cutter point is an estimated contour error. Compared with conventional estimation methods, the real-time self-adaptive contour error estimation method is more accurate in estimation precision. In particular, the method can still have a great effect and exhibit excellent algorithm robustness when the estimation effects of the conventional methods suddenly become bad in a condition with high speed movement and high curvature of a curve. Moreover, the method needs moderate computational complexity, fully meets the requirement of real-time applications, and is highly practical.

The invention discloses multi-scale automatic detection system and method for profile errors of a T-shaped guide rail. A high-precision linear guide rail is arranged on a detection platform, wherein two laser sensors respectively in a horizontal direction and a vertical direction are put at one end of a measurement rack on the guide rail, while the other end of the measurement rack is connected with a synchronous belt driven by a stepper motor so as to ensure that the measurement rack moves along the guide rail; two proximity switches and two limit switches arranged at both ends of the guide rail are used for controlling start and stop positions of the measurement rack and protecting the measurement rack; a side face of the detection platform is provided with a pair of supporting shafts and three positioning blocks, which are used for supporting and positioning a workpiece; the stepper motor is controlled to drive the measurement rack to move through a programmable logic unit; meanwhile, displacement values of the position of the measurement rack and the two laser sensors and the states of the two proximity switches and the two limit switches are acquired, and the communication with an upper computer is realized; and noise removal and filtration are carried out on measured data by the upper computer so as to obtain multi-scale indexes of profile errors of the measured workpiece. The invention can accomplish the measurements of the side face and the top face of the T-shaped guide rail.

The invention relates to the field of numerical control machine tools, and particularly discloses a contour error suppression method for a digital twin-driven multi-axis numerical control machine tool. The method comprises the steps of S1 establishing a virtual model of a digital twinborn body corresponding to a physical entity, and adopting a multi-parameter gain scheduling control strategy based on a global task coordinate system, so as to obtain a time-varying coupling mechanism model of a multi-axis feeding system; establishing a data driving model of the multi-axis feeding system by using signal testing and machine learning; S2 performing virtual-real synchronization, and establishing a bidirectional sensing relationship between the digital twinborn body and the physical entity through a communication protocol with strong compatibility; S3 dynamically estimating a contour error; and S4 contour error suppression: according to the pre-estimation model, adopting a multi-objective optimization algorithm to obtain an optimal motion control parameter and a track maximum limiting speed corresponding to the optimal motion control parameter. By adopting the technical scheme of the invention, the contour error can be effectively reduced.