361 results about "Geometric error" patented technology

The invention discloses a method for measuring a geometric error parameter value of a rotary oscillation axis of a five-axis linkage numerical control machine tool. The method comprises the following steps of: measuring displacement errors of X, Y and Z directions on at least three positions under different rotating angles of the rotary oscillation axis respectively by using a ballbar, wherein translation axis linkage coordinates provided by a revolving tool central point (RTCP) cutter central point movement control function of a five-axis machine tool serve as measurement datum; and performing data processing according to the displacement errors to identify and calculate the geometric error of each rotating angle of the rotary oscillation axis. The rotary oscillation axis is measured independently by the method, so the geometric error value of the five-axis linkage numerical control machine tools of various structures at each rotary oscillation angles can be obtained. The method is not limited by the structures of the machine tools, is convenient to arrange and has high measuring precision.

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.

A thermal deformation error compensation method for a coordinate measuring machine creates thermal deformation and geometric error data at different ambient temperatures including temperatures and machine kinematic parameters to obtain a thermal deformation and geometric error model, and inputs the model into central control unit of the coordinate measuring machine, and converts a 3D error compensation to obtain a thermal deformation and geometric error compensation model, and uses the thermal deformation and geometric error compensation model for performing compensations, so as to complete a thermal deformation and geometric error compensation of the coordinate measuring machine.

The invention discloses a numerical control machine tool translational shaft geometric error measuring device and measuring and identifying method. A laser tracker is used for successively measuring axial feed movements of three fixed points of a single machine tool translational shaft at four different positions, the real-time poses of the translation shaft is calculated by the special continuous moving trajectory of the three fixed points, and errors of a machine tool are identified. Due to the fact the real-time poses of the translation shaft are measured, the acquired machine tool information is much richer than the information acquired by only measuring cutter moving trajectory, and error identification algorithm is quite simple. The method suitable for fast data processing, machine tool error fast compensation and precision detection in the field of machine tools has the advantages of high precision, fast and simple operation, rich measuring information, and the like.

The invention relates to a time-domain ground-air electromagnetic detection system and a calibration method, in particular to a system consisting of an induction signal recording device connected with a ground recording device global position system (GPS) synchronization unit, a closed abnormal ring and a data quality evaluation system, and a calibration method for the time-domain ground-air electromagnetic detection system. The closed abnormal ring and the induction signal recording device are adopted, the induction current and induction voltage are simultaneously recorded, and the 24-bit 200Hz sampling rate, a bandwidth of 0-13KHz and a dynamic range of an amplifier of 160dB are achieved. Moreover, the system is synchronous with a ground transmitter and an air receiver GPS, and during measurement, by removing earth background field data, a pure closed abnormal ring electromagnetic signal containing a geometric error is extracted, is input into the data quality evaluation system, andis compared and fitted with the computed closed abnormal ring theoretical value, the system error, the geometric parameter error and the detection resolution of the time-domain ground-air electromagnetic detection system are determined, and the performance of the electromagnetic detection system is tested and calibrated.

The invention provides a concrete mixing blade die-face design system and a method based on springback compensation, which comprises three modules, that is, a die-face automatic springback compensation design module based on numerical simulation, a die-face CAD reconstruction design module, and a die-face correction module based on reverse engineering, thus a concrete mixing blade die-face CAD-CAE-CAD integrated system based on the springback compensation is formed, and geometric errors produced after the blade being formed are required to satisfy design requirements on the level of numerical simulation, thus reducing correction times; and the process of converting a CAE model after a virtual die repair into a CAD geometric model which can be designed and manufactured is finished, a digital model after the blade being actually pressed is acquired by utilizing a reverse engineering technology and then is compared with the required design shape of the blade, and springback deviation is obtained so as to be used for guiding the actual die repair process of the blade, thus correcting the residual springback deviation and further improving the precision of the springback compensation on the basis of numerical simulation springback compensation.

The invention provides a method for analyzing the machining precision reliability sensitivity of a numerically-controlled machine tool, belongs to the field of machine tool precision design, and particularly relates to a space error modeling method of a three-axis machine tool and a method for analyzing the machining precision reliability and the machining precision reliability sensitivity of the machine tool. A multi-body system motion feature analysis method is used for setting up a space error model of the machine tool, and combined with a Monte-carlo digital analogy method for analyzing the machining precision reliability of the machine tool, and the degree of influence on the machining precision reliability from the wave action of all items of geometric errors of the machine tool, so that the critical geometric errors influencing the machining precision reliability are identified. Guiding advice can be given for designing, assembling and machining of the machine tool, and the machining precision reliability of the machine tool is improved fundamentally.

The invention discloses a LaserTRACER-based method for detecting and identifying geometrical errors of translational shafts of a numerical control machine tool. The geometrical error detecting and identifying method comprises the following steps of: constructing a measuring system consisting of the numerical control machine tool and LaserTRACER, and measuring by utilizing the measuring system to obtain machine tool tail end pose errors; establishing a mapping model between 21 geometrical errors of the numerical control machine tool and the abovementioned machine tool tail end pose errors; establishing a mapping model between the machine tool tail end pose errors and multinomial coefficient vectors of the 21 geometrical errors; establishing an identification equation set of the abovementioned multinomial coefficient vectors; carrying out identifiability analysis on the identification equation set of the multinomial coefficient vectors p; and carrying out simulating optimization on a measurement trajectory in a working space by use of Matlab, and the like. On the premise of measuring a relatively small amount of data, a relatively good identification effect is achieved, and data support is provided for machining capability evaluation and error compensation of the numerical control machine tool.

The invention provides a three-axis numerical control machine tool key geometric error identification method based on global sensitivity analysis, belongs to the field of machine tool accuracy design, and particularly relates to a three-axis machine tool space error modeling method and a three-axis machine tool geometric error global sensitivity analysis method. On the basis of machine tool space error models built through the multi-body theory and geometric error measurement, global sensitivity analysis is conducted on various geometric errors of a machine tool, and influence on machining accuracy of the coupling effect of the geometric errors is obtained. A new machine tool design concept is provided, and the problem of machine tool accuracy is fundamentally solved. Guiding suggestions can be put forward for practical assembly and machining, therefore, output of errors is reduced, the machining accuracy of the numerical control machine tool is improved, and the problem of the machine tool accuracy is fundamentally solved.

The invention discloses a muti-constraint-based high-precision binocular camera calibration method. The method comprises the steps that initial binocular camera parameters are calculated through a Zhang zhengyou calibration method, and re-projection errors and polar line errors are calculated, and then according to feature point coordinates in left and right camera images and the binocular cameraparameters, three-dimensional feature points are rebuilt; 3D geometric errors formed by adjacent distance errors, collinear errors and right angle errors are calculated. An optimized objective function formed by re-projection error cumulative sum, adjacent distance error cumulative sum, collinear error cumulative sum and right angle error cumulative sum is built, the optimized objective function is solved through a Levenberg-Marquardt method, and the optimal binocular camera parameters are obtained. Compared with the Zhang zhengyou calibration method, a binocular camera is calibrated, the distance measurement errors, collinear errors and right angle errors are obviously lowered.

The invention belongs to the field of geometric error measurement for machine tools and relates to a method for measuring dynamic space track errors of the machine tools by means of binocular vision, in particular to a dynamic error vision measurement method for a five-axis numerical control machine tool. The measurement method includes the steps that according to a three-dimension perceptive function of binocular vision measurement, multiple errors are measured and separated at a single time; and four types of spherical mark points are reasonably distributed at a machine tool cutter end and on the surface of a working table, and the position relation among a vision coordinate system, a machine tool reference coordinate system and a machine tool cutter principal axis coordinate system is calibrated by means of feature information of the spherical mark points. During measurement, a vision measurement system continuously, statically and dynamically collects images of the spherical mark points, then moving errors of all machine tool axes are solved, and the obtained theoretical value and actual machine tool moving amount are combined, so that the moving errors of each axis are solved. According to the dynamic error vision measurement method for the five-axis numerical control machine tool, the machine tool space track errors are measured by means of a binocular high-speed camera, so that the error measurement accuracy is improved, the measurement range of the machine tool moving track is widened, the measurement method is simple and reliable, and the measurement process is simplified.

A geometric error identification method of multi-axis machine tool includes a measuring step of indexing a position of a target ball mounted on one of a main spindle and a table into a plurality of angles around an rotation axis, and measuring the position of the target ball at respective indexed positions by using a touch probe mounted on the other one of the main spindle and the table, a geometric error calculation step of calculating a geometric error from the measured position of the target ball, an ellipse-expression calculation step of calculating an ellipse approximate expression by an arc trajectory measured by operating the rotation axis, and an error correcting step of calculating and correcting a scaling error of translation axes from the calculated ellipse approximate expression.

A method and apparatus for estimating error in a multi-axis controlled machine is applicable to any type of machine configuration in order to estimate and confirm in advance the final position and the posture of the machine, which are produced when geometric errors of the machine are synthesized. The method includes defining the structure of the multi-axis controlled machine subjected to error estimation; and defining parameters, which represent behaviors of drive axes having geometric error and relationships between the drive axes according to the defined structure of the multi-axis controlled machine, adding the defined parameters by applying the parameters to a generalized error synthesis model, and generating an error synthesis model of the multi-axis controlled machine by applying a result of parametric modeling in response to a result of the adding.

The invention discloses a numerical control precision progressive forming device and a precision progressive forming method for plates, and belongs to the technical field of plate processing. The device comprises a five-axis numerical control forming machine, a plate fixture, a data acquisition system and an optimal control module, wherein the plate fixture is arranged on a worktable of the machine; the data acquisition system is connected with the five-axis numerical control forming machine and the optimal control module respectively, and transmits processing parameters and control instructions; the tail end of a spindle of the five-axis numerical control forming machine is provided with a forming pressure head or a laser ranging system; and the laser ranging system is connected with thedata acquisition system and transmits a laser ranging signal. By alternately using the forming pressure head and the laser ranging system, cyclic operation including plate progressive forming, error measurement and formed path modified forming is completed. The device can save development cost of a die, avoid occupying a press, ensure the dimensional accuracy of sheet metal parts, and reduce material loss due to geometric errors in actual production.

Methods and systems for evaluating the performance of multiple patterning processes are presented. Patterned structures are measured and one or more parameter values characterizing geometric errors induced by the multiple patterning process are determined. In some examples, a primary, multiple patterned target is measured and a value of a parameter of interest is directly determined from the measured data by a Signal Response Metrology (SRM) measurement model. In some other examples, a primary, multiple patterned target and an assist target are measured and a value of a parameter of interest is directly determined from the measured data by a Signal Response Metrology (SRM) measurement model. In some other examples, a primary, multiple patterned target is measured at different process steps and a value of a parameter of interest is directly determined from the measured data by a Signal Response Metrology (SRM) measurement model.

The invention discloses an analysis method on the basis of distribution characteristics of a space machining error of a numerical control machine tool, belongs to the field of accuracy design of a machine tool and particularly relates to an analysis method on the basis of the distribution characteristics of the space error. On the basis of space geometric error deterministic modeling and geometric error measurement which are established by a multibody system and the matrix total differential and random process principle, a space error deterministic analysis model of a precision horizontal machining center is established and the distribution characteristics of a geometric error and the space machining error of the machine tool are analyzed. The invention discloses a novel machine tool design concept and fundamentally solves the problem of accuracy of the machine tool. Guiding suggestions also can be given to actual assembling and machining, so that output of the error is reduced, machining accuracy of the numerical control machine tool is improved and the problem of accuracy of the machine tool is fundamentally solved.

The invention relates to a method for evaluating geometrical error of a compound spatial moulding surface, belonging to the field of mechanic parts geometrical error evaluation. The method comprises the following steps: (1) a three-dimensional CAD model of a work piece to be evaluated is read and an ideal work piece model is reconstructed; (2) geometrical data of the work piece to be evaluated is measured to obtain the coordinate information of each measured point; (3) the error value of the measured moulding surface is calculated according to the geometrical error evaluation items of the work piece to be measured including spatial straightness accuracy, cylindricity and punch combination compound position; and (4) the error evaluation result is compared with the read ideal work piece model for analyzing, the processing error information is displayed by adopting colour cloud points, and the error evaluation report is obtained finally. The invention, by the approaching process for constructing minimum zone, realizes fast and accurate evaluation on the geometrical error of the compound spatial moulding surface.

The invention belongs to the field of machine tool accuracy designing, and relates to a method for designing geometric accuracy of a multi-axis numerical control machine tool to improve processing accuracy reliability, in particular to a modeling method of space errors of the multi-axis numerical control machine tool and an analyzing method of processing accuracy reliability and reliability sensitivity of the machine tool. A space error model of the multi-axis numerical control machine tool and a processing accuracy reliability model as well as a processing accuracy sensitivity model of the multi-axis numerical control machine tool under a multi-failure mode are built, geometric error items high in processing accuracy reliability sensitivity are optimized, processing accuracy reliability of the machine tool is improved, a basis is provided for acquiring interrelation among geometric errors of the multi-axis numerical control machine tool and setting accuracy grade of main transmission components of the machine tool, and the problem of accuracy distribution of the machine tool is solved fundamentally.

The invention discloses an assessment method for geometric errors of a five-axis tool machine, and the assessment method can be applied to a five-axis processing machine. The assessment method includes the steps that an R-test measuring tool with a probe and a standard ball is arranged on the five-axis machining machine, the sphere center of the standard ball serves as the original point of a reference coordinate system, a five-axis synchronous movement path serves as a measuring path to measure the assembly error of the five-axis tool machine, the assembly error obtained through measuring and a known mechanism parameter of the five-axis tool machine are substituted in a geometric error model, and values of 11 items of geometric errors of the five-axis tool machine are obtained through solving by using a method of least square. The assessment method has the advantages of being fast and accurate.

Along with increasing demand on machining precision, how to reasonably configure geometric error of a machine tool under the premise of ensuring the machining performance of the machine tool to balance the cost and machining precision is the problem demanding a prompt solution in manufacturing of the machine tool. The invention provides a novel multi-target optimal distributing method for geometric accuracy based on the manufacturing cost and quality loss of parts. The method comprises the following steps of: establishing a comprehensive spatial error model of geometric error of the machine tool by a multibody system theory; establishing a manufacturing cost model of a machine tool part according to the machining characteristic of the machine tool part which affects the geometric error to the maximum extent; meanwhile, combining the quality loss cost to establish a cost-based target function; establishing an optimal model associated to precise level of the part by identifying the geometric error, namely, maximizing European norms of all precision parameter variables as another target function; and realizing optimal distribution through Isight and Matlab integrated and combined with NSGA-II (Nondominated Sorting Genetic Algorithm-II).

The invention relates to the technical field of machine tool geometric error measuring and calibration, in particular to a five-axis gear making machine tool position independent error detection method based on a small-cutting-amount test piece. The detection method comprises the following steps that firstly, a track is compiled according to the shape of a designed test piece, a processing code is generated, small-amount cutting is conducted on the designed test piece, and a cutting test piece with a specific to-be-tested object is obtained; secondly, sensitive direction coordinates of the cutting surface of the specific to-be-tested object on the cutting test piece are detected and acquired by utilization of an on-line measuring head, and coordinate mismatching values corresponding to the cutting surface are calculated; thirdly, a homogeneous kinematic equation containing a position independent error is established, and the mapping relation between the coordinate mismatching values corresponding to the cutting surface, and the position independent error is determined; and fourthly, a position independent error item is obtained according to the mapping relation between the coordinate mismatching values corresponding to the cutting surface, and the position independent error. The fixe-axis gear making machine tool position independent error detecting and identifying method is efficient and easy to operate.

The invention discloses a machine tool rotating shaft geometry error six-circle identifying method based on measuring of a ball bar instrument. The method comprises the following steps of determining six measuring positions of the ball bar instrument according to the type and position of a machine tool rotating shaft, obtaining the relation of the readings of the ball bar instrument at all positions and the geometry error of the rotating shaft according to the influence of the geometry error of the rotating shaft to the machine tool precision and in combination with the direction of the ball bar instrument at six measuring positions, obtaining an identifying matrix M of the geometry error of the rotating shaft, by combining each geometry error definition of the rotating shaft, obtaining an identifying formula of the geometry error of the rotating shaft, selecting appropriate coordinates for the six measuring positions to install the ball bar instrument, operating corresponding machine tool codes, obtaining the corresponding readings of the ball bar instrument at the six positions of the rotating shaft, substituting the readings of the ball bar instrument and the measuring position coordinates into the identifying formula of the geometry error of the rotating shaft, and obtaining all 10 geometry errors of each rotating shaft. The method is suitable for the rotating shafts in different types without principle error, the system entry is good, the measuring is convenient, and the identifying precision is high.

The invention discloses a numerical control program post-processing method for five-coordinate linkage machine tools, which includes the following steps: (1) a machine tool geometric error compensation parameter method is adopted to compile a numerical control program, so that codes can be universally used on machine tools with like systems; (2) the numerical control program points generated by the machine tool software are reversely calculated into the points in a programming coordinate system, the points in the programming coordinate system are then normally calculated into machine tools with other systems, and therefore the codes are universally used on machine tools with various systems. The method solves the problem that programs complied in the conventional mode cannot be universally used, and also solves the contradiction between the RPCP (Rotation Around Part Center Point) and RTCP (Rotation Around Tool Center Point) programming modes and the conventional program-debugging habit of workshop workers, debugging is simple, rapid and reliable, and mistakes are prevented.

The invention discloses a five-axis linkage machine tool RTCP dynamic precision calibrating apparatus and a calibrating method thereof. The apparatus comprises a support, and a first face contact type dial gauge and a second face contact type dial gauge both arranged on the support. The central axes of the two face contact type dial gauges are perpendicular to each other and located in the same plane. The apparatus satisfies the following formula: d1=d2<=r-3mm. d1 is the distance between the measuring end face of the first face contact type dial gauge to the vertically intersecting point of the central axes of the two face contact type dial gauges. d2 is the distance between the measuring end face of the second face contact type dial gauge to the vertically intersecting point of the central axes of the two face contact type dial gauges. r is the bulb radius of a bulb test rod for calibration. By using the two face contact type dial gauges arranged on the support, the apparatus prevents complex equation solving processes, conventional dial gauge calculating errors and measuring geometric errors, and complex operations during a conventional calibration method using process. The calibration efficiency and the calibration precision are thus greatly improved. The invention further discloses a calibrating method for the five-axis linkage machine tool RTCP dynamic precision calibrating apparatus.