Coordinate measuring machine control system and method

Abstract

The invention relates to the field of three-coordinate measurement technology, and in particular to a three-coordinate measuring machine control system and method. The control system comprises a main controller, which comprises a main control module, a motion control module, a probe trigger control module, a bus communication module, a first error compensation module, a second error compensation module and a state monitoring module. The main controller is connected to a probe controller via a trigger through cable, and a contact probe is connected to the output end of the probe controller. The main controller is also connected to a single-axis drive controller via a power cable, a bus cable, a coordinate latch through cable and an emergency stop through cable. The probe trigger control module receives a probe controller trigger signal and drives the coordinate latch through cable to latch coordinate data. The invention ensures that coordinate data is latched and read in real time and an emergency stop command is transmitted in time when the contact probe is triggered. The measurement errors caused by temperature and dust are compensated, and the accuracy of measuring workpieces by a measuring machine is improved.

Description

Technical Field

[0001] The present invention relates to the technical field of three-coordinate measurement, and in particular to a three-coordinate measuring machine control system and method. Background Art

[0002] The structure of the three-coordinate measuring machine control system is divided into two types: upper and lower computer type and integrated type; the integrated upper computer adopts a standard PC or industrial control computer, Windows operating system, and the control card is also inserted into the upper computer. The upper computer not only installs and runs the measurement software, but also installs and runs the motion control software. The measurement software and the control software communicate through DDE and other trial methods, and use Windows' time-sharing control to achieve multi-task processing; for the integrated structure of the CNC system, the instability of the Windows system itself seriously affects its stability and reliability; because the user can operate the computer at will, it is easy to be attacked by viruses, and the control program may be damaged due to misoperation, etc., resulting in measurement errors caused by the bus transmission delay when the data is locked using the bus. At the same time, when using the three-coordinate measurement system for measurement, the surrounding temperature and dust will accumulate and increase over time, and the corresponding measurement error value will also increase accordingly, resulting in inaccurate measurement by the measuring machine.

[0003] Therefore, it is necessary to propose a three-coordinate measuring machine control system and a control method thereof that can improve the above problems. Summary of the invention

[0004] The purpose of the present invention is to overcome the defects of the prior art and provide a three-coordinate measuring machine control system and method.

[0005] The present invention provides a three-coordinate measuring machine control system, characterized in that it comprises a main controller; The main controller includes a main control module, a motion control module, a probe trigger control module, a bus communication module, a first error compensation module, a second error compensation module and a state monitoring module; The main controller is connected to a probe controller via a trigger through cable, the output end of the probe controller is connected to a contact probe, and the main controller is also connected to a single-axis drive controller via a power cable, a bus cable, a coordinate latch through cable and an emergency stop through cable, the probe trigger control module receives a trigger signal from the probe controller to drive the coordinate latch through cable to latch the coordinate data, and then reads it through the bus communication module; The single-axis drive controller is also connected to the linear grating ruler, the rotary encoder, the DC motor, and the limit switch, and is used to receive the motion command of the main controller, directly read the linear grating ruler and the rotary encoder data, and transmit the motion planning data to the single-axis drive controller through the motion control module to realize the three-loop control of the position loop, the speed loop and the current loop, and control the driving DC motor to realize the measurement of the workpiece; The first error compensation module is used to calibrate and correct the error of the linear grating scale; The main controller also includes a temperature detection module and a temperature error compensation module; The temperature detection module is used to detect the actual temperature of the coordinate measuring machine control system; A temperature error compensation module is used to calculate a first error compensation amount caused by a temperature change of a three-coordinate measuring machine control system according to actual temperature data and a preset temperature-error relationship model, and to compensate for the error of the three-coordinate measuring machine control system; The second error compensation module is used to calculate the second error compensation amount caused by the change of the temperature and operating state parameters of the three-dimensional coordinate measuring machine control system according to the actual temperature data and the preset temperature-error relationship model, and compensate for the measurement error between the contour of the workpiece to be measured and the contour of the standard workpiece; The main controller is connected to the temperature detection module, the temperature error compensation module and the second error compensation module. When the main controller determines that the temperature of the three-coordinate measuring machine control system exceeds a set threshold range, the temperature error compensation module and the second error compensation module cooperate to perform measurement error compensation. The main controller adjusts the motion control signal of the measuring machine according to the first error compensation amount and the second error compensation amount to achieve accurate compensation for the error of the three-coordinate measuring machine control system.

[0006] Further, the second error compensation module includes a drawing module, a display module, a calculation module, an adjustment module and a judgment module connected in sequence; The drawing module is also connected to the main control module, and is used to draw the standard workpiece contour as the first image through the main machine of the three-dimensional coordinate measuring machine, and the contact probe measures the contour of the workpiece to be measured as the second image; The display device is used for displaying a first image of the standard workpiece contour and a second image of the contour of the workpiece to be measured by the contact probe; The adjustment module is used to make the contour boundary of the first image close to the contour boundary of the second image; The calculation module is used to calculate the distance between any contour point of the first image and the corresponding contour point of the second image; The judging module is used to store a distance threshold and judge the size between the distance and the distance threshold.

[0007] Furthermore, the second error compensation module further comprises a probe error compensation module, which is connected to the judgment module and is used to perform probe wear error compensation on the workpiece to be measured.

[0008] Furthermore, it also includes an operating handle; the bus communication module is also connected to the operating handle via a bus cable; A control method for a three-coordinate measuring machine comprises the following steps: Step 1: a trigger through cable is set between the probe controller and the main controller, and a power cable, a bus cable, a coordinate latch through cable and an emergency stop through cable are set between the main controller and the single-axis drive controller. The probe trigger control module receives the trigger signal of the probe controller, and drives the coordinate latch through cable to latch the coordinate data, and latches the rotary encoder and linear grating ruler data in each single-axis drive controller in real time, and then reads it through the bus communication module, so as to ensure that the coordinate data is latched and read in real time and the emergency stop command is transmitted in time when the contact probe is triggered; Step 2: The motion planning data is transmitted to the single-axis drive controller through the motion control module to realize the three-loop control of the position loop, speed loop and current loop. The single-axis drive controller controls the drive DC motor to realize the measurement of the workpiece; Step 3: The state monitoring module is used to obtain the coordinate data fed back by the single-axis drive controller of the three-dimensional coordinate measuring machine during operation, the limit switch status, the status of the probe trigger control module, and the status information of the operating handle in real time, and the status information data is analyzed to obtain the overall performance indicators for evaluating the three-dimensional coordinate measuring machine; Step 4: Calibrate and correct the linear grating ruler error through the first error compensation module, calculate the second error compensation amount caused by the change of the temperature and operating state parameters of the three-dimensional coordinate measuring machine control system through the second error compensation module according to the actual temperature data and the preset temperature-error relationship model, and compensate for the measurement error between the contour of the workpiece to be measured and the contour of the standard workpiece; when the main controller determines that the temperature of the three-dimensional coordinate measuring machine control system exceeds the set threshold range; the temperature error compensation module and the second error compensation module cooperate to compensate for the measurement error, and the main controller adjusts the motion control signal of the measuring machine according to the first error compensation amount and the second error compensation amount, so as to realize accurate compensation for the error of the three-dimensional coordinate measuring machine control system; Step 5: An emergency stop direct cable is set between the main controller and the single-axis drive controller. The main controller sends an emergency stop command to the single-axis drive controller through the emergency stop direct cable, so that the single-axis drive controller receives the emergency stop command in real time and controls the DC motor to stop rotating.

[0009] Further, step 4 also includes compensating the measurement error between the contour of the workpiece to be measured and the contour of the standard workpiece by a second error compensation module; Obtain the coordinate value of the contour of the workpiece to be measured by the current contact probe; Presetting a three-dimensional coordinate deviation threshold range between the coordinate values ​​of the workpiece contour to be measured by the contact probe and the standard workpiece contour; Determine whether the three-dimensional coordinate value difference between the contour coordinate value of the workpiece to be measured by the current contact probe and the contour coordinate value of the standard workpiece is within the three-dimensional coordinate deviation threshold range; if not, adjust the parameters of the current workpiece to be measured and the contact probe through the adjustment module so that the contour boundary of the first image is close to the contour boundary of the second image; if so, it means that the current workpiece to be measured is close to the contour measured by the probe, the contact probe is not worn, and no error compensation is required; if not, the contact probe is worn, and the probe wear error compensation is performed on the workpiece to be measured, and then measure again after compensation; Compared with the prior art, the present invention has the following beneficial effects: The three-coordinate measuring machine control system provided by the present invention is provided with a trigger through cable, a coordinate latch through cable and an emergency stop through cable; a trigger through cable is added between a probe controller and a main controller, and a coordinate latch through cable and an emergency stop through cable are added between the main controller and a single-axis drive controller; the coordinate latch through cable is controlled by the main controller to directly generate a latch signal, and real-time rotary encoder and linear grating ruler data in each single-axis drive controller are latched in real time, and then a command is read through a bus communication module, and the latched data is read from each single-axis drive controller, so as to ensure that the coordinate data is latched and read in real time and the emergency stop command is transmitted in time when the contact probe is triggered, thereby avoiding the measurement error caused by the bus transmission delay when the data is latched in a bus manner; at the same time, a first error compensation module and a second error compensation module are provided, the first error compensation module is used for calibrating and correcting the error of the linear grating ruler; the second error compensation module is used for compensating for the measurement error between the contour of the workpiece to be measured and the contour of the standard workpiece, and the measurement error compensation is performed in coordination with the second error compensation module and the temperature error compensation module, so as to compensate for the measurement error caused by temperature and dust, so that the workpiece is measured with more accurate precision. BRIEF DESCRIPTION OF THE DRAWINGS

[0010] The following drawings are only used to illustrate and explain the present invention, and are not used to limit the scope of the present invention, wherein: FIG1 is a schematic diagram of the main controller structure of the present invention; FIG2 is a schematic diagram of the control system structure of the present invention; The main structure in the figure is: 1-main controller, 2-single-axis drive controller, 3-operating handle, 4-emergency stop direct cable, 5-coordinate latch direct cable, 6-bus cable, 7-linear grating ruler, 8-rotary encoder, 9-DC motor, 10-contact probe, 11-probe controller, 12-trigger direct cable, 15-bus communication module, 16-status monitoring module, 17-motion control module, 18-main control module, 19-probe trigger control module, 20-first error compensation module, 21-second error compensation module. DETAILED DESCRIPTION

[0011] In order to make the purpose, technical solution, design method and advantages of the present invention clearer, the present invention is further described in detail by specific embodiments in conjunction with the accompanying drawings. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not used to limit the present invention.

[0012] like Figure 1-2 As shown, the present invention provides a three-coordinate measuring machine control system, including a main controller 1; The main controller 1 includes a main control module 18, a motion control module 17, a probe trigger control module 19, a bus communication module 15, a first error compensation module 20, a second error compensation module 21 and a state monitoring module 16; The main controller 1 is connected to a probe controller 11 via a trigger through cable 12, a contact probe 10 is connected to the output end of the probe controller 11, and the main controller 1 is also connected to a single-axis drive controller 2 via a power cable, a bus cable 6, a coordinate latch through cable 5 and an emergency stop through cable 4, the probe trigger control module 19 receives a trigger signal from the probe controller 11 to drive the coordinate latch through cable 5 to latch the coordinate data, and then reads it through the bus communication module 15; and the bus communication module 15 also communicates with the single-axis drive controller 2 and the operating handle 3; The single-axis drive controller 2 is also connected to the linear grating ruler 7, the rotary encoder 8, the DC motor 9, and the limit switch, and is used to receive the motion command of the main controller 1, directly read the data of the linear grating ruler 7 and the rotary encoder 8, and transmit the motion planning data to the single-axis drive controller 2 through the motion control module 17 to realize the three-loop control of the position loop, the speed loop and the current loop, and control the driving DC motor 9 to realize the measurement of the workpiece; It should be noted that the three-coordinate measuring machine control system is composed of a main controller 1, three single-axis drive controllers 2, a probe controller 11, an operating handle 3 and other components; The main controller 1 is an ARM chip with built-in serial communication function; this embodiment uses its high computing speed to realize a large amount of calculation and system processing in motion control, uses the USB bus to communicate with the computer host, and uses its serial bus to realize communication between various controllers in the control system.

[0013] The ARM main control chip implements functions including the main control module 18, the motion control module 17, the bus communication module 15, the first error compensation module 20, the second error compensation module 21 and the state monitoring module 16; Wherein, the first error compensation module 20 is used to calibrate and correct the error of the linear grating ruler 7; The main controller 1 also includes a temperature detection module and a temperature error compensation module; The temperature detection module is used to detect the actual temperature of the coordinate measuring machine control system; A temperature error compensation module is used to calculate a first error compensation amount caused by a temperature change of a three-coordinate measuring machine control system according to actual temperature data and a preset temperature-error relationship model, and to compensate for the error of the three-coordinate measuring machine control system; The second error compensation module 21 is used to calculate the second error compensation amount caused by the change of the temperature and operating state parameters of the three-dimensional coordinate measuring machine control system according to the actual temperature data and the preset temperature-error relationship model, and compensate for the measurement error between the contour of the workpiece to be measured and the contour of the standard workpiece; The main controller 1 is connected to the temperature detection module, the temperature error compensation module and the second error compensation module 21, and is used to determine through the main controller 1 that when the temperature of the three-dimensional coordinate measuring machine control system exceeds the set threshold range; the temperature error compensation module and the second error compensation module 21 cooperate to perform measurement error compensation, and the main controller 1 adjusts the motion control signal of the measuring machine according to the first error compensation amount and the second error compensation amount to achieve accurate compensation for the error of the three-dimensional coordinate measuring machine control system.

[0014] It should be noted that the master control module 18 is responsible for coordinating the work between the various functional modules within the main controller 1, ensuring that the motion control module 17, the probe trigger control module 19, the bus communication module 15, the first error compensation module 20 and the state monitoring module 16 can operate in an orderly and coordinated manner. For example, during the measurement process, when the motion control module 17 executes the motion instruction of the measuring machine, the master control module 18 will coordinate the bus communication module 15 to obtain the position information and state data of each axis in a timely manner, and at the same time notify the first error compensation module 20 and the second error compensation module 21 to make real-time corrections to the measurement data, ensuring the accuracy and stability of the entire measuring machine system; The motion control module 17 completes motion decomposition and planning according to the host motion command, divides the displacement motion mode and the speed motion mode, and transmits the planning data to the single-axis drive controller 2 through the bus to realize three-loop control; The probe trigger control module 19 receives the trigger signal of the probe controller 11 to drive the coordinate latch through cable 5 to latch the coordinate data, and then reads it through the bus communication module 15. The bus communication module 15 also completes the communication function with the single-axis drive controller 2 and the operating handle 3. The first error compensation module 20 compensates and corrects the error of the linear grating ruler 7, and monitors the state of the three-dimensional coordinate measuring machine through the state monitoring module 16.

[0015] The single-axis drive controller 2 realizes data reading and drive control, including reading relevant data and realizing three-loop control according to the motion planning instructions of the main controller to ensure the response speed and control performance rigidity; Among them, the single-axis drive controller 2 realizes the motion control and drive of one axis in the three-dimensional coordinate measuring machine, as well as the two functions of data reading. The single-axis drive controller 2 adopts the architecture of DSP (Digital Signal Process) + FPGA (Field-Programmable Gate Array), which can be used to realize high-speed logic processing functions, read linear grating ruler 7 data, rotary encoder 8 data, etc., which can effectively make up for the shortcomings of DSP in this regard; In order to solve the problem of bus transmission delay, a trigger through cable 12, a coordinate latch through cable 5 and an emergency stop through cable 4 are provided to ensure that the coordinate data is latched and read in real time and the emergency stop command is transmitted in time when the contact probe 10 is triggered; According to the motion command sent by the main controller 1, the single-axis drive controller 2 converts the command into a suitable current or voltage signal and outputs it to the DC motor 9, controls the speed, direction and torque of the DC motor 9, and makes the measuring machine move according to the predetermined trajectory and speed to achieve the measurement operation of the workpiece. For example, when the contact probe 10 of the measuring machine needs to move in a certain direction for measurement, the single-axis drive controller controls the rotation of the DC motor according to the motion plan, and converts the rotational motion of the DC motor 9 into the linear motion of the probe through the mechanical transmission mechanism to complete the measurement task; The probe trigger control module 19 is implemented by analog circuit and transistor direct drive amplification mode; the module receives the probe trigger signal from the probe controller 11, and directly drives the coordinate latch through cables 5 on the three single-axis drive controllers 2 with this signal; The probe controller 11 is connected to the contact probe 10. When the probe of the contact probe 10 captures the trigger signal, the three single-axis drive controllers 2 can immediately receive the trigger pulse. The first error compensation module 20 in the main controller 1 provides two functions: error calibration and error correction. When the three-dimensional coordinate measuring machine leaves the factory, the error calibration function is used to read the deviation between the laser interferometer data and the linear grating ruler 7 data to obtain the correction value of each calibration position; during the normal operation of the three-dimensional coordinate measuring machine, the error correction function corrects the linear grating ruler 7 data read from the single-axis drive controller 2 in real time, and feeds the corrected value back to the host for calculation to ensure high measurement accuracy; Further, the second error compensation module 21 includes a drawing module, a display module, a calculation module, an adjustment module and a judgment module connected in sequence; The drawing module is also connected to the main control module 18, and is used to draw the standard workpiece contour as the first image through the host of the three-dimensional coordinate measuring machine, and the contact probe measures the contour of the workpiece to be measured as the second image; The display device is used for displaying a first image of the standard workpiece contour and a second image of the workpiece contour to be measured by the contact probe; The adjustment module is used to make the contour boundary of the first image close to the contour boundary of the second image; The calculation module is used to calculate the distance from any contour point of the first image to the corresponding contour point of the second image; The judging module is used to store a distance threshold and judge the size between the distance and the distance threshold.

[0016] Furthermore, the second error compensation module further comprises a probe error compensation module, which is connected to the judgment module and is used to perform probe wear error compensation on the workpiece to be measured.

[0017] Furthermore, it also includes an operating handle 3; the bus communication module 15 is also connected to the operating handle 3 via a bus cable 6; It should be noted that, for the problem of synchronous acquisition of coordinate data when the contact probe 10 is triggered, the present embodiment adopts a contact probe 10 trigger signal directly connected to the single-axis drive controller 2, the probe controller 11 is connected to the main controller 1 through a trigger direct cable 12, and the probe controller 11 is connected to the contact probe 10; the main controller 1 is connected to the single-axis drive controller 2 through a coordinate latch direct cable 5, and the single-axis drive controller 2 is connected to the rotary encoder 8 and the linear grating ruler 7; The probe controller 11 is connected to the main controller 1 through a trigger direct cable 12, and the main controller 1 and the three single-axis drive controllers 2 are connected through coordinate latch direct cables 5 respectively; the trigger direct cable 12 directly sends the trigger signal of the probe controller 11 to the probe trigger control module 19, and the probe trigger control module 19 directly drives the coordinate latch direct cables 5 on the three-way single-axis drive controllers 2; the coordinate latch direct cable 5 controls the direct generation of a latch signal, and then reads the command through the bus communication module 15, and reads the latched data from each single-axis drive controller, so as to ensure the real-time latching and reading of the coordinate data and the timely transmission of the emergency stop command when the contact probe is triggered, thereby avoiding the measurement error caused by the bus transmission delay when the data is latched in the bus mode; This embodiment also adopts an emergency stop direct cable 4 solution similar to the coordinate lock direct cable 5. The main controller 1 and the single-axis drive controller 2 are connected via the emergency stop direct cable 4. The emergency stop command sent by the main controller 1 can be directly transmitted to the single-axis drive controller 2, so that the single-axis drive controller 2 can receive the emergency stop command in real time without any additional delay, so as to ensure the safety of the three-coordinate measuring machine or the operator in extreme situations.

[0018] The control method of the coordinate measuring machine includes the following steps: Step 1: a trigger direct cable 12 is set between the probe controller 11 and the main controller 1, and a power cable, a bus cable 6, a coordinate latch direct cable 5 and an emergency stop direct cable 4 are set between the main controller 1 and the single-axis drive controller 2. The probe trigger control module 19 receives the trigger signal of the probe controller 11, and drives the coordinate latch direct cable 5 to latch the coordinate data, and latches the real-time data of the rotary encoder 8 and the linear grating ruler 7 in each single-axis drive controller 2 in real time, and then reads it through the bus communication module 15, so as to ensure that the coordinate data is latched and read in real time and the emergency stop command is transmitted in time when the contact probe 10 is triggered; Step 2: The motion planning data is transmitted to the single-axis drive controller 2 through the motion control module 17 to realize the three-loop control of the position loop, the speed loop and the current loop. The single-axis drive controller 2 controls the driving DC motor 9 to realize the measurement of the workpiece; Step 3: The state monitoring module 16 is connected to the single-axis drive controller 2, the probe trigger control module 19, and the operating handle 3 to obtain the coordinate data, the limit switch status, the status of the probe trigger control module 19, and the status information of the operating handle 3 fed back by the single-axis drive controller 2 during the operation of the three-dimensional coordinate measuring machine in real time, and analyze the status information data to obtain the overall performance indicators for evaluating the three-dimensional coordinate measuring machine; the overall performance indicators include measurement accuracy, repeatability, and stability; the state monitoring module 16 can analyze the relevant data to find out the factors that may affect the measurement accuracy (such as too fast movement speed, unstable contact probe triggering, etc.), and make optimization suggestions to the operator or maintenance personnel, such as adjusting the movement parameters, checking the probe trigger device, etc., to improve the overall performance of the measuring machine; Step 4: Calibrate and correct the error of the linear grating ruler 7 through the first error compensation module 20, calculate the second error compensation amount caused by the change of the temperature and operating state parameters of the three-dimensional coordinate measuring machine control system through the second error compensation module 21 according to the actual temperature data and the preset temperature-error relationship model, and compensate for the measurement error between the contour of the workpiece to be measured and the contour of the standard workpiece; when the main controller 1 determines that the temperature of the three-dimensional coordinate measuring machine control system exceeds the set threshold range; the temperature error compensation module and the second error compensation module 21 cooperate to compensate for the measurement error, and the main controller 1 adjusts the motion control signal of the measuring machine according to the first error compensation amount and the second error compensation amount, so as to realize accurate compensation for the error of the three-dimensional coordinate measuring machine control system; Step 4.1: The first error compensation module 20 calibrates and corrects the error of the linear grating ruler 7; Step 4.2: The main controller 1 further includes a temperature detection module and a temperature error compensation module; The temperature detection module is used to detect the actual temperature of the coordinate measuring machine control system. A temperature error compensation module is used to calculate a first error compensation amount caused by a temperature change of a three-coordinate measuring machine control system according to actual temperature data and a preset temperature-error relationship model, and to compensate for the error of the three-coordinate measuring machine control system; The main controller 1 is connected with the temperature detection module, the temperature error compensation module and the second error compensation module 21, and is used for, when the main controller 1 determines that the temperature of the three-dimensional coordinate measuring machine control system exceeds the set threshold range, the temperature error compensation module and the second error compensation module 21 cooperate to perform measurement error compensation, and the controller adjusts the motion control signal of the measuring machine according to the first error compensation amount and the second error compensation amount, so as to achieve accurate compensation for the error of the three-dimensional coordinate measuring machine control system; It should be noted that when the temperature error compensation module determines that the temperature exceeds the threshold range through the main controller 1, the temperature error compensation module calculates the first error compensation amount caused by temperature change based on the actual temperature data detected by the temperature detection module and the preset temperature-error relationship model (the model is a linear model, that is, error = a×temperature + b; where a and b are coefficients to be determined; the model describes the quantitative relationship between temperature change and measurement error). For example, if the model shows that the measured length of a certain axis will increase by 0.01mm for every 5°C increase in temperature, and the current temperature is 10°C higher than the normal temperature, then the temperature error compensation module will calculate that the measurement error of the axis at the current temperature is 0.02mm; the second error compensation module 21 is used to further correct and adjust the error calculated by the temperature error compensation module based on the temperature and other operating status parameters (such as movement speed, load conditions, etc.) of the three-coordinate measuring machine control system during the measurement process. For example, when the measuring machine is running at high speed and with a large load, even if the temperature changes are the same, the impact on the measurement accuracy may be different from that at low speed and no load. The second error compensation module 21 will calculate the second error compensation amount caused by the change in the temperature and operating state parameters of the three-dimensional coordinate measuring machine control system based on these comprehensive factors; the temperature error compensation module and the second error compensation module 21 work together to achieve measurement error compensation, and compensate for the measurement error between the contour of the workpiece to be measured and the contour of the standard workpiece; for example, when measuring the diameter of a circular workpiece, if the measuring axis of the measuring machine expands due to the increase in temperature, thereby causing the measurement result to be larger, the main controller 1 will make corresponding corrections to the measurement result according to the error compensation amount to make it closer to the true value, thereby ensuring that the three-dimensional coordinate measuring machine control system can maintain a high measurement accuracy under different temperature environments, and improving the reliability and accuracy of the measurement results; The second error compensation module 21 is used to calculate the second error compensation amount caused by the change of the temperature and operating state parameters of the three-dimensional coordinate measuring machine control system according to the actual temperature data and the preset temperature-error relationship model, and further compensate for the measurement error between the contour of the workpiece to be measured and the contour of the standard workpiece; specifically includes: Obtaining the coordinate value of the contour of the workpiece to be measured by the current contact probe 10; A threshold range of three-dimensional coordinate deviation between the contour of the workpiece to be measured and the coordinate value of the contour of the standard workpiece measured by the contact probe 10 is preset; Determine whether the three-dimensional coordinate value difference between the contour coordinate value of the workpiece to be measured by the current contact probe 10 and the contour coordinate value of the standard workpiece is within the three-dimensional coordinate deviation threshold range; if not, adjust the parameters of the current workpiece to be measured and the contact probe through the adjustment module so that the contour boundary of the first image is close to the contour boundary of the second image; if so, it means that the current workpiece to be measured is close to the contour measured by the probe, the contact probe 10 is not worn, and no error compensation is required; if not, the contact probe 10 is worn, and the probe wear error compensation is performed on the workpiece to be measured, and then measure again after compensation; Step 5: The main controller 1 is connected to the single-axis drive controller 2 through the emergency stop direct cable 4, and the emergency stop command sent by the main controller 1 is transmitted to the single-axis drive controller 2 through the emergency stop direct cable 4, so that the single-axis drive controller 2 receives the emergency stop command in real time; the DC motor 9 is controlled to stop rotating; It is worth noting that the coordinate measuring machine control system of the present invention adopts a distributed control method with a serial bus structure, adds a trigger through cable 12 between the probe controller 11 and the main controller 1, and adds a coordinate lock through cable 5 between the main controller 1 and the single-axis drive controller 2. The coordinate lock through cable 5 is controlled by the main controller 1. The control directly generates a latch signal, and latches the real-time rotary encoder 8 and linear grating ruler 7 data in each single-axis drive controller 2 in real time. Then, the command is read through the bus communication module 15, and the latched data is read from each single-axis drive controller 2, so as to ensure that the coordinate data is latched and read in real time and the emergency stop command is transmitted in time when the contact probe 10 is triggered, thereby avoiding the measurement error caused by the bus transmission delay when the data is latched in the bus mode. At the same time, a first error compensation module and a second error compensation module are set. The first error compensation module is used to calibrate and correct the error of the linear grating ruler 7; the second error compensation module is used to compensate for the measurement error between the contour of the workpiece to be measured and the contour of the standard workpiece, wherein the second error compensation module and the temperature error compensation module are used to coordinately perform measurement error compensation, and the measurement errors caused by temperature and dust are compensated, so that the accuracy of the workpiece measurement is more accurate.

[0019] The serial numbers of the above embodiments of the present invention are only for description and do not represent the advantages or disadvantages of the embodiments.

[0020] The above description is only a preferred embodiment of the present invention and is not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc. made within the spirit and principle of the present invention should be included in the protection scope of the present invention.

Claims

1. A three-coordinate measuring machine control system, characterized in that: comprising a main controller (1); The main controller (1) comprises a main control module (18), a motion control module (17), a probe trigger control module (19), a bus communication module (15), a first error compensation module (20), a second error compensation module (21) and a state monitoring module (16); The main controller (1) is connected to a probe controller (11) via a trigger through cable (12); an output end of the probe controller (11) is connected to a contact probe (10); and the main controller (1) is also connected to a single-axis drive controller (2) via a power cable, a bus cable (6), a coordinate latch through cable (5) and an emergency stop through cable (4); the probe trigger control module (19) receives a trigger signal from the probe controller (11) to drive the coordinate latch through cable (5) to latch coordinate data, which is then read via a bus communication module (15); The single-axis drive controller (2) is also connected to the linear grating ruler (7), the rotary encoder (8), the DC motor (9), and the limit switch, and is used to receive motion commands from the main controller (1), directly read the data of the linear grating ruler (7) and the rotary encoder (8), and transmit the motion planning data to the single-axis drive controller (2) through the motion control module (17) to realize three-loop control of the position loop, the speed loop and the current loop; and control the driving DC motor (9) to realize the measurement of the workpiece; The first error compensation module (20) is used to calibrate and correct the error of the linear grating ruler (7); The main controller (1) also includes a temperature detection module and a temperature error compensation module; The temperature detection module is used to detect the actual temperature of the coordinate measuring machine control system; A temperature error compensation module is used to calculate a first error compensation amount caused by a temperature change of a three-coordinate measuring machine control system according to actual temperature data and a preset temperature-error relationship model, and to compensate for the error of the three-coordinate measuring machine control system; The second error compensation module (21) is used to calculate a second error compensation amount caused by changes in the temperature and operating state parameters of the three-dimensional coordinate measuring machine control system based on actual temperature data and a preset temperature-error relationship model, and to compensate for the measurement error between the contour of the workpiece to be measured and the contour of the standard workpiece; The main controller (1) is connected to a temperature detection module, a temperature error compensation module and a second error compensation module (21), and is used to determine through the main controller (1) that when the temperature of a three-dimensional coordinate measuring machine control system exceeds a set threshold range; the temperature error compensation module and the second error compensation module (21) cooperate to perform measurement error compensation, and the main controller (1) adjusts the motion control signal of the measuring machine according to the first error compensation amount and the second error compensation amount, thereby realizing accurate compensation for the error of the three-dimensional coordinate measuring machine control system.

2. A three-coordinate measuring machine control system according to claim 1, characterized in that: The second error compensation module (21) comprises a drawing module, a display module, a calculation module, an adjustment module and a judgment module which are connected in sequence; The drawing module is also connected to the main control module (18) and is used to draw the standard workpiece profile as a first image through the main machine of the three-dimensional coordinate measuring machine, and the contact probe (10) measures the profile of the workpiece to be measured as a second image; The display device is used for displaying a first image of the standard workpiece contour and a second image of the workpiece contour to be measured by the contact probe; The adjustment module is used to make the contour boundary of the first image close to the contour boundary of the second image; The calculation module is used to calculate the distance from any contour point of the first image to the corresponding contour point of the second image; The judging module is used to store a distance threshold and judge the size between the distance and the distance threshold.

3. A three-coordinate measuring machine control system according to claim 2, characterized in that: The second error compensation module further comprises a probe error compensation module, which is connected to the judgment module and is used to perform probe wear error compensation on the workpiece to be measured.

4. A three-coordinate measuring machine control system according to claim 1, characterized in that: It also includes an operating handle (3); the bus communication module (15) is also connected to the operating handle (3) via a bus cable (6).

5. A control method for a three-coordinate measuring machine, characterized in that: The method comprises the following steps: Step 1: a trigger through cable (12) is arranged between the probe controller (11) and the main controller (1); a power cable, a bus cable (6), a coordinate latch through cable (5) and an emergency stop through cable (4) are arranged between the main controller (1) and the single-axis drive controller (2); the probe trigger control module (19) receives a trigger signal from the probe controller (11), and drives the coordinate latch through cable (5) to latch coordinate data; real-time latches the data of the rotary encoder (8) and the linear grating ruler (7) in each single-axis drive controller (2); and then reads the data through the bus communication module (15), so as to ensure that the coordinate data is latched and read in real time and the emergency stop command is transmitted in time when the contact probe (10) is triggered; Step 2: The motion planning data is transmitted to the single-axis drive controller (2) through the motion control module (17) to realize the three-loop control of the position loop, the speed loop and the current loop. The single-axis drive controller (2) controls the drive DC motor (9) to realize the measurement of the workpiece; Step 3: obtaining coordinate data fed back by the single-axis drive controller (2), the limit switch status, the status of the probe trigger control module (19), and the status information of the operating handle (3) in real time during the operation of the three-dimensional coordinate measuring machine through the status monitoring module (16), and analyzing the status information data to obtain the overall performance index for evaluating the three-dimensional coordinate measuring machine; Step 4: Calibrate and correct the error of the linear grating ruler (7) through the first error compensation module (20); calculate the second error compensation amount caused by the change of the temperature and operating state parameters of the three-dimensional coordinate measuring machine control system through the second error compensation module (21) according to the actual temperature data and the preset temperature-error relationship model, and compensate for the measurement error between the contour of the workpiece to be measured and the contour of the standard workpiece; when the main controller (1) determines that the temperature of the three-dimensional coordinate measuring machine control system exceeds the set threshold range; the temperature error compensation module and the second error compensation module (21) cooperate to perform measurement error compensation, and the main controller (1) adjusts the motion control signal of the measuring machine according to the first error compensation amount and the second error compensation amount, so as to achieve accurate compensation for the error of the three-dimensional coordinate measuring machine control system; Step 5: An emergency stop direct cable (4) is provided between the main controller (1) and the single-axis drive controller (2). The main controller (1) sends an emergency stop command which is transmitted to the single-axis drive controller (2) via the emergency stop direct cable (4), so that the single-axis drive controller (2) receives the emergency stop command in real time and controls the DC motor (9) to stop rotating.

6. A control method for a three-dimensional coordinate measuring machine according to claim 5, characterized in that: Step 4 also includes compensating the measurement error between the contour of the workpiece to be measured and the contour of the standard workpiece by a second error compensation module (21); Obtaining the coordinate value of the contour of the workpiece to be measured by the current contact probe (10); Presetting a threshold range of three-dimensional coordinate deviation between the contour of a workpiece to be measured and the coordinate value of the contour of a standard workpiece measured by the contact probe (10); It is determined whether the three-dimensional coordinate value difference between the contour coordinate value of the workpiece to be measured by the current contact probe (10) and the contour coordinate value of the standard workpiece is within the three-dimensional coordinate deviation threshold range; if not, the parameters of the current workpiece to be measured and the contact probe are adjusted by an adjustment module so that the contour boundary of the first image is close to the contour boundary of the second image; if so, it means that the current workpiece to be measured is close to the contour measured by the probe, the contact probe (10) is not worn, and error compensation is not required; if not, the contact probe (10) is worn, and the probe wear error compensation is performed on the workpiece to be measured, and then measurement is performed after compensation.

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