A detection, calibration and control method for the stroke and position of an operating mechanism

Abstract

The present invention relates to the field of electrical control technology, and particularly to a detection, calibration and control method for the stroke and position of an operating mechanism, including marking the positions of calibration points of a position encoder according to position markers at known distance intervals; marking the positions of static magnetic grid calibration points corresponding to the calibration points of the position encoder; the PLC / controller detecting the data of the position encoder and the static magnetic grid data of the operating mechanism, and calibrating the linear calculation relationship between the position encoder of the operating mechanism and the stroke in real time in a signal edge triggering manner; the PLC / controller precisely controlling the preset target point of the operating mechanism according to the position of the operating mechanism calculated by the corresponding stroke relationship. This technical solution uses the dual detection data of a position encoder combined with a static magnetic grid sensor to perform real-time multi-point dynamic calibration and precise control on the operating mechanism.

Description

Technical Field

[0001] The present invention relates to the technical field of electrical control, and particularly to a detection and calibration control method for the stroke and position of a running mechanism. Background Art

[0002] For the detection of the stroke and position of the running mechanism of a crane or other transportation machinery, the method of "wheel / roller + encoder" is often adopted. However, this detection method cannot solve the errors caused by slipping and wear, so it is mostly used for stroke detection or stroke deviation detection with low requirements for accuracy and reliability. In addition, there is also a method of using sensors installed in full stroke in different forms for stroke or stroke deviation detection. Its detection accuracy is significantly improved, but the cost and system complexity also increase accordingly. Some detection methods also have the disadvantage of poor environmental adaptability. In this regard, there is a Chinese patent document with the publication number CN203889920U in the prior art, which discloses a deviation correction control device for a large-span gantry crane. The deviation correction control device for a large-span gantry crane disclosed in this patent document can eliminate the short-distance cumulative error by collecting two position information of a position encoder and a deviation correction position travel switch and controlling calibration and zero clearing through a processor. Since the position encoder detection belongs to indirect detection, problems such as slipping and wear are likely to occur during the rotation of the wheel. In long-distance detection, the position encoder cannot eliminate the cumulative deviation in time, and the detection accuracy will become lower and lower until the next calibration and zero clearing; furthermore, if the running mechanism reciprocates and does not pass through the zero point, the position encoder will not be calibrated and zero cleared, and the cumulative deviation caused by slipping and wear cannot be eliminated; finally, the proximity switch has detection errors and is affected by speed, and the accuracy of the calibration and zero clearing point cannot be guaranteed. For the above reasons, the deviation correction control device for a large-span gantry crane cannot fully and effectively guarantee the detection accuracy and reliability of the position encoder.

[0003] Based on the defects existing in the above prior art, a Chinese patent document with the publication number CN109883445A discloses a detection and calibration control method for the stroke and position of a running mechanism to overcome the corresponding defects. However, this method still has the following defects:

[0004] 1) The zero position of the running mechanism is no longer modified after calibration. In this way, the error caused by slipping and wear of the running mechanism will cause the reference zero point to drift. After the drift, the detected reference zero point of the running mechanism will be inconsistent with the actual reference zero point. When calculating the stroke relationship formula, it will be affected by the drift of the reference zero point, resulting in a decrease in accuracy and abnormal data near the reference zero point;

[0005] 2) The relational expression between the position of the operating mechanism and the code value signal of the displacement encoder is calculated and determined by L = Ln / (Xn - Xo)X - Ln*Xo / (Xn - Xo), where Ln is the predetermined permanent magnet position, and Xn is the code value signal value corresponding to the predetermined permanent magnet position. The relational expression is derived from the reference zero point L0 = 0, and the linear relationship correction of the calibration points other than the reference zero point is performed using multiple predetermined permanent magnet positions and encoder code values. Based on this, due to the problem of the data refresh cycle of the encoder and the static magnetic grating, the calibration point of the static magnetic grating cannot be accurately identified during detection, but only a certain area near the calibration point can be identified, that is, the calibration area. This calibration area is affected by the speed of the operating mechanism. The greater the speed, the larger the area, and the greater the data volatility in the area. After calculating the travel relational expression, the error is also greater. Summary of the Invention

[0006] In order to overcome the defects of the above-mentioned prior art, the present invention provides a detection, calibration and control method for the travel and position of an operating mechanism, which is specifically realized by the following technical solutions:

[0007] A detection, calibration and control method for the travel and position of an operating mechanism includes the following steps:

[0008] S1, Install the position encoder on the wheel set of the operating mechanism so that the position encoder rotates synchronously with the wheels, and use the PLC / controller to detect the code value data of the position encoder in real time;

[0009] S2, Set multiple permanent magnet position points at known distance intervals along the track length direction, install permanent magnets on the ground below the track corresponding to the permanent magnet position points, determine the magnet calibration points according to the permanent magnet position points, and then install the static magnetic grating sensor at the lower end of the wheel set of the operating mechanism;

[0010] S3, Start the operating mechanism. During the movement of the operating mechanism, mark the positions of the calibration points of the position encoder based on the magnet calibration points, and input the position data of the calibration points of the encoder into the PLC / controller; at the same time, mark the positions of the static magnetic grating calibration points corresponding to the calibration points of the position encoder, and input the positions of the magnet calibration points read by the static magnetic grating sensor into the PLC / controller;

[0011] S4. Use the PLC / controller to obtain the position encoder data and static magnetic grid sensor data of the operating mechanism, and adopt the signal edge trigger method to calibrate the linear calculation relationship and offset correction relationship of the position encoder of the operating mechanism in real time. Among them, the linear calculation relationship is determined by the position encoder calibration point positions and magnetic steel calibration point positions corresponding to the first and last magnetic steels, and the offset correction relationship is determined by the position encoder calibration point positions and magnetic steel calibration point positions corresponding to the magnetic steels other than the first and last magnetic steels. During this period, every time the static magnetic grid sensor passes through a magnetic steel and passes through the static magnetic grid calibration point position, the position detected by the position encoder is calibrated once, and the relationship between the position encoder and the stroke is updated. By analogy, the detection and calibration control of the operating mechanism stroke and position are completed;

[0012] S5. Use the PLC / controller to accurately control the preset target point of the operating mechanism according to the position of the operating mechanism calculated by the stroke relationship formula of the calibrated position encoder.

[0013] Preferably, in step S1, the position encoder is connected to the wheel set through a coupling, the wheel set drives the position encoder to rotate through the coupling, and the position encoder converts the rotation angle into the position change amount of the operating mechanism.

[0014] Preferably, in step S3, the calibration point of the position encoder refers to the installation position of the magnetic steel corresponding to the position encoder when the magnetic steel is under the static magnetic grid sensor in the stopped state of the operating mechanism. The PLC / controller reads the current position encoder code value signal, that is, obtains the position encoder code value signal value corresponding to the installation position of the current magnetic steel, which is the position encoder calibration point position.

[0015] Preferably, in step S3, the static magnetic grid calibration point refers to when the static magnetic grid sensor moves to directly above the magnetic steel with the operating mechanism, the vertical distance between the static magnetic grid sensor and the magnetic steel is 0 - 15 millimeters, the static magnetic grid sensor senses the magnetic field information of the magnetic steel, the static magnetic grid sensor will induce magnetic field signals at different positions on its body, and finally output the specific calibration point data of the magnetic steel under the static magnetic grid sensor. The static magnetic grid sensor reads the magnetic steel calibration point data sensed by the static magnetic grid sensor according to the position encoder calibration point positions, that is, the static magnetic grid calibration point position.

[0016] Preferably, in step S4, adopting the signal edge trigger method, when the stroke mechanism passes through the first magnetic steel, the linear calculation relationship formula between the position encoder and the stroke calculated by the PLC / controller is: Y = k×X + b; where Y represents the position data of the operating mechanism; k and b are the coefficients in the linear calculation relationship formula; X is the position encoder code value data read by the PLC / controller.

[0017] Preferably, in step S4, when the travel mechanism passes through the first permanent magnet, in the linear calculation relationship,

[0018]

[0019]

[0020] M1 = L1 + P1′ - J1;

[0021] When the travel mechanism passes through the last permanent magnet, in the linear calculation relationship,

[0022]

[0023]

[0024] Mn = Ln + Pn′ - Jn;

[0025] Among them, Ln is the permanent magnet calibration point data of the nth permanent magnet, M1 is the actual detected permanent magnet calibration point position of the first permanent magnet; Xn is the position encoder code value data corresponding to the calibration point position of the nth permanent magnet, and n is equal to the total number of permanent magnets; X1’ is the position encoder code value data read by the PLC / controller in real time when the travel mechanism reaches the calibration point of the first permanent magnet; L1 is the permanent magnet calibration point data of the first permanent magnet, P1’ is the static magnetic grid sensor position data read by the PLC / controller in real time when the travel mechanism reaches the calibration point position of the first permanent magnet; J1 is the static magnetic grid sensor position data marking the calibration point position of the first permanent magnet; Mn is the actual detected permanent magnet calibration point position of the nth permanent magnet; Pn’ is the static magnetic grid sensor position data read by the PLC / controller in real time when the travel mechanism reaches the calibration point position of the nth permanent magnet; Jn is the static magnetic grid sensor position data marking the calibration point position of the nth permanent magnet.

[0026] Preferably, in step S4, the offset correction relationship between the position encoder and the travel is:

[0027] Y = k×X + b + ΔY;

[0028] ΔY = Lm - Ym - Jm + Pm, 1 < m < n;

[0029] ΔY is the offset between the position encoder and the travel; Ym is the position encoder position data calculated by the PLC / controller through the linear calculation relationship used when passing through the previous permanent magnet when the travel mechanism reaches the calibration point position of the mth permanent magnet, Lm is the permanent magnet calibration point data of the mth permanent magnet, Pm’ is the static magnetic grid position data read by the PLC / controller in real time when the travel mechanism reaches the calibration point position of the mth permanent magnet, and Jm is the static magnetic grid position data marking the calibration point position of the mth permanent magnet.

[0030] Advantages of the present invention:

[0031] 1) This technical solution uses a PLC / controller to detect the data of the position encoder of the operating mechanism and the data of the static magnetic grating, and adopts the signal edge trigger method to calibrate the linear calculation relationship of the position encoder of the operating mechanism in real time. The linear calculation relationship is determined by the position encoder calibration points and the magnetic steel calibration points corresponding to the first and the last magnetic steels; the offset correction relationship of the position encoder of the operating mechanism is calibrated in real time by the signal edge trigger method, and the offset correction relationship is determined by the position encoder calibration points and the magnetic steel calibration points corresponding to the middle part of the arranged magnetic steels. Thus, this technical solution uses the dual detection data of the position encoder combined with the static magnetic grating sensor to perform real-time multi-point dynamic calibration and precise control on the operating mechanism. In addition, two different position calibration mechanisms are adopted, which can effectively eliminate the two major defect problems of the corresponding prior art.

[0032] 2) In the present invention, since the magnetic steel position points, i.e., the magnetic steel calibration points, are pre-fixed, the error of the displacement encoder can be effectively corrected through the known fixed magnetic steel calibration points, and the relationship between the position of the operating mechanism and the code value signal of the displacement encoder can be corrected, thereby improving the accuracy of the displacement encoder; compared with other prior arts, the dual data of the displacement encoder combined with the static magnetic grating sensor are used to perform real-time dynamic calibration and precise control on the operating mechanism, significantly improving the accuracy and reliability of detection, and having the characteristics of convenient operation and good adaptability.

[0033] 3) By installing a plurality of magnetic steels at predetermined positions along the track length direction on the ground under the track, with the magnetic steels close to the web side of the track, installing the displacement encoder on the wheels of the operating mechanism, and installing the static magnetic grating sensor at the lower end of the frame of the operating mechanism, it has the characteristics of flexible arrangement and good applicability.

[0034] 4) In the present invention, every time the static magnetic grating sensor passes through a magnetic steel and passes through the static magnetic grating calibration point position, the position detected by the position encoder is calibrated once, and the relationship between the position encoder and the stroke is updated, and so on, to complete the detection and calibration control of the stroke and position of the operating mechanism. Through real-time calibration, the deviation caused by the wear change of the wheel diameter and the running slip can be effectively eliminated, thereby significantly improving the accuracy and reliability of the position detection of the operating mechanism. Description of the Drawings

[0035] Figure 1 is the on-site implementation schematic diagram of this technical solution;

[0036] Figure 2 Real-time calibration of the first magnetic steel Figure Ⅰ ;

[0037] Figure 3 Real-time calibration of the first magnetic steelFigure Ⅱ ;

[0038] Figure 4 Calibrate the real-time for the last magnet Figure Ⅰ ;

[0039] Figure 5 Calibrate the real-time for the last magnet Figure Ⅱ ;

[0040] Figure 6 Calibrate the real-time for the middle magnets Figure Ⅰ ;

[0041] Figure 7 Calibrate the real-time for the middle magnets Figure Ⅱ ;

[0042] Figure 8 Calibrate the real-time for the middle magnets Figure Ⅲ ;

[0043] Figure 9 Calibrate the real-time for the middle magnets Figure Ⅳ ;

[0044] In the figure:

[0045] 1. Operating mechanism; 2. Position encoder; 3. Magnet; 4. Static magnetic grating sensor; 5. Track. Specific implementation manner

[0046] To make the objectives, technical solutions and advantages of the invention clearer, the technical solutions in the present invention will be clearly and completely described below with reference to the accompanying drawings in the present invention. Obviously, the described embodiments are some, but not all, of the embodiments of the present invention.

[0047] Therefore, the detailed description of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely represents selected embodiments of the present invention. All other embodiments obtained by those of ordinary skill in the art based on the embodiments in the present invention without creative efforts fall within the scope of protection of the present invention.

[0048] Embodiment 1

[0049] This embodiment discloses a detection, calibration and control method for the travel and position of an operating mechanism. As a preferred implementation of the present invention, it includes the following steps:

[0050] S1, as Figure 1As shown in the figure, the position encoder is installed on the wheel set of the running mechanism so that the position encoder rotates synchronously with the wheel. Specifically, the position encoder is connected to the wheel set through a coupling, and the wheel set drives the position encoder to rotate through the coupling. The position encoder converts the rotation angle into the position change amount of the running mechanism, and then the PLC / controller is used to detect the code value data of the position encoder in real time.

[0051] S2, as Figure 1 shown in the figure, set multiple magnet position points at known distance intervals along the track length direction (as Figure 1 shown in the figure, the distances from L0 to L1, from L1 to L2, etc. are all the same), install magnets on the ground under the track corresponding to the magnet position points, determine the magnet calibration points according to the magnet position points, and then install the static magnetic grating sensor at the lower end of the wheel set of the running mechanism.

[0052] S3, start the running mechanism. During the movement of the running mechanism, mark the positions of each calibration point of the position encoder based on the magnet calibration points, and input the position data of each calibration point of the encoder into the PLC / controller; at the same time, mark the positions of the static magnetic grating calibration points corresponding to the positions of each calibration point of the position encoder, and input the positions of each magnet calibration point read by the static magnetic grating sensor into the PLC / controller; among them, the static magnetic grating sensor includes a static magnetic grating source (magnet) and a static magnetic grating scale (static magnetic grating). When the static magnetic grating source (magnet) makes a non-contact relative movement along the axis of the static magnetic grating scale, the digital position information is resolved by the static magnetic grating scale (static magnetic grating).

[0053] S4, use the PLC / controller to obtain the data of the position encoder of the running mechanism and the data of the static magnetic grating sensor, and calibrate the linear calculation relationship of the position encoder of the running mechanism and the offset correction relationship of the position encoder of the running mechanism in real time by using the signal edge trigger method; among them, the linear calculation relationship is determined by the positions of the calibration points of the position encoder corresponding to the first and last magnets and the positions of the magnet calibration points, and the offset correction relationship is determined by the positions of the calibration points of the position encoder corresponding to the magnets other than the first and last magnets and the positions of the magnet calibration points; during this period, every time the static magnetic grating sensor passes through a magnet and passes through the position of the static magnetic grating calibration point, the position detected by the position encoder is calibrated once, and the relationship between the position encoder and the stroke is updated, and so on, to complete the detection and calibration control of the stroke and position of the running mechanism.

[0054] Among them, the edge trigger means a conversion from a high level to a low level, or vice versa, and this conversion process triggers a signal action. Due to the high-speed operation of the operating mechanism, there is a signal processing cycle for the position encoder and the static magnetic grid sensor, and the signal processing cycle may cause the system to be unable to read data, that is, a dead zone is generated. To eliminate the influence of the dead zone, taking the calibration point of the static magnetic grid sensor as the midpoint, the dead zone positions are set before and after. The outside of the dead zone positions is at a high level, and the inside of the dead zone positions is at a low level.

[0055] S5. Use the PLC / controller to accurately control the preset target point of the operating mechanism based on the position of the operating mechanism calculated according to the stroke relationship formula of the calibrated position encoder.

[0056] This technical solution uses the PLC / controller to detect the data of the position encoder of the operating mechanism and the static magnetic grid data, and adopts the signal edge trigger method to calibrate the linear calculation relationship of the position encoder of the operating mechanism in real time. The linear calculation relationship is determined by the position encoder calibration point positions and the magnetic grid calibration point positions corresponding to the first and last magnetic steels; the signal edge trigger method is adopted to calibrate the offset correction relationship of the position encoder of the operating mechanism in real time. The offset correction relationship is determined by the position encoder calibration point positions and the magnetic grid calibration point positions corresponding to the middle part of the arranged magnetic steels (except the first and last magnetic steels). In summary, this technical solution uses the dual detection data of the position encoder combined with the static magnetic grid sensor to perform real-time multi-point dynamic calibration and precise control on the operating mechanism. In addition, two different position calibration mechanisms are adopted, which can effectively eliminate the two major defect problems of the corresponding prior art.

[0057] Embodiment 2

[0058] This embodiment discloses a method for detecting, calibrating and controlling the stroke and position of an operating mechanism. As a preferred implementation of the present invention, it includes the following steps:

[0059] A method for detecting, calibrating and controlling the stroke and position of an operating mechanism, characterized by including the following steps:

[0060] S1. Install the position encoder on the wheel set of the operating mechanism so that the position encoder rotates synchronously with the wheel, and use the PLC / controller to detect the code value data of the position encoder in real time.

[0061] S2. Set a plurality of magnetic steel position points at known distance intervals along the track length direction, install magnetic steels on the ground below the corresponding magnetic steel position points, determine the magnetic grid calibration points according to the magnetic steel position points, and then install the static magnetic grid sensor at the lower end of the wheel set of the operating mechanism.

[0062] S3. Start the operating mechanism. During the movement of the operating mechanism, calibrate the positions of the calibration points of the position encoder based on the magnet steel calibration points, and input the position data of the calibration points of the encoder into the PLC / controller. At the same time, mark the static magnetic grating calibration point positions corresponding to the calibration point positions of the position encoder, and input the position data of each magnet steel calibration point read by the static magnetic grating sensor into the PLC / controller.

[0063] Among them, the calibration point of the position encoder refers to the installation position of the magnet steel corresponding to the position encoder when the operating mechanism is in a stopped state and the magnet steel is below the static magnetic grating sensor. The PLC / controller reads the code value signal of the current position encoder, and thus obtains the code value signal value corresponding to the installation position of the current magnet steel, which is the position of the calibration point of the position encoder.

[0064] In addition, the static magnetic grating calibration point means that when the static magnetic grating sensor moves to directly above the magnet steel with the operating mechanism, the vertical distance between the static magnetic grating sensor and the magnet steel is 0 - 15 mm. The static magnetic grating sensor senses the magnetic field information of the magnet steel, and the static magnetic grating sensor will induce magnetic field signals at different positions on its body, and finally output the specific calibration point data of the magnet steel below the static magnetic grating sensor. The static magnetic grating sensor reads the magnet steel calibration point data sensed by the static magnetic grating sensor according to the calibration point positions of the position encoder, that is, the static magnetic grating calibration point position.

[0065] S4. Use the PLC / controller to obtain the position encoder data and static magnetic grating sensor data of the operating mechanism, and adopt the signal edge trigger method to calibrate the linear calculation relationship and offset correction relationship of the position encoder of the operating mechanism in real time; among them, the linear calculation relationship is determined by the position encoder calibration point positions and magnet steel calibration point positions corresponding to the first and last magnet steels, and the offset correction relationship is determined by the position encoder calibration point positions and magnet steel calibration point positions corresponding to the magnet steels other than the first and last magnet steels; during this period, every time the static magnetic grating sensor passes a magnet steel and passes through the static magnetic grating calibration point position, the position detected by the position encoder is calibrated once, and the relationship between the position encoder and the stroke is updated, and so on, to complete the detection and calibration control of the stroke and position of the operating mechanism.

[0066] S5. Use the PLC / controller to accurately control the preset target point of the operating mechanism according to the position of the operating mechanism calculated by the stroke relationship formula of the calibrated position encoder.

[0067] Embodiment 3

[0068] This embodiment discloses a method for detecting and calibrating the stroke and position of an operating mechanism. As a preferred implementation of the present invention, it includes the following steps:

[0069] S1. Install the position encoder on the wheel set of the running mechanism so that the position encoder rotates synchronously with the wheel, and use the PLC / controller to detect the code value data of the position encoder in real time.

[0070] S2. Set multiple magnet position points at known distance intervals along the track length direction. Install magnets on the ground below the corresponding magnet position points, determine the magnet calibration points according to the magnet position points, and then install the static magnetic grating sensor at the lower end of the wheel set of the running mechanism.

[0071] S3. Start the running mechanism. During the movement of the running mechanism, mark the positions of the calibration points of the position encoder based on the magnet calibration points, and input the position data of the calibration points of the encoder into the PLC / controller; at the same time, mark the positions of the static magnetic grating calibration points corresponding to the calibration points of the position encoder, and input the positions of the magnet calibration points read by the static magnetic grating sensor into the PLC / controller.

[0072] S4. Use the PLC / controller to obtain the position encoder data and static magnetic grating sensor data of the running mechanism, and adopt the signal edge trigger method to calibrate the linear calculation relationship of the position encoder of the running mechanism and the offset correction relationship of the position encoder of the running mechanism in real time; among them, the linear calculation relationship is determined by the position encoder calibration point positions and magnet calibration point positions corresponding to the first and last magnets, and the offset correction relationship is determined by the position encoder calibration point positions and magnet calibration point positions corresponding to the magnets other than the first and last magnets; during this period, every time the static magnetic grating sensor passes through a magnet and passes through the static magnetic grating calibration point position, the position detected by the position encoder is calibrated once, and the relationship between the position encoder and the stroke is updated, and so on, to complete the detection and calibration control of the stroke and position of the running mechanism.

[0073] Among them, when the stroke mechanism passes through the first magnet by adopting the signal edge trigger method, the linear calculation relationship formula between the position encoder and the stroke calculated by the PLC / controller is: Y = k×X + b; where, Y represents the position data of the running mechanism; k and b are the coefficients in the linear calculation relationship formula; X is the code value data of the position encoder read by the PLC / controller.

[0074] Further, based on the above linear calculation relationship formula, when the stroke mechanism passes through the first magnet, as Figure 2 and Figure 3 shown, in the linear calculation relationship formula, there is the following set of deduction formulas:

[0075]

[0076]

[0077]

[0078] Further, based on the above linear calculation relationship, when the travel mechanism passes through the last magnet, as Figure 4 and Figure 5 shown, in the linear calculation relationship, there is the following calculation formula group two:

[0079]

[0080]

[0081]

[0082] Among them, Ln is the magnet calibration point data of the nth magnet, M1 is the actual detected magnet calibration point position of the first magnet; Xn is the position encoder code value data corresponding to the calibration point position of the nth magnet, and n is equal to the total number of magnets; X1' is the position encoder code value data read by the PLC / controller in real time when the travel mechanism reaches the calibration point of the first magnet; L1 is the magnet calibration point data of the first magnet, P1' is the static magnetic grating sensor position data read by the PLC / controller in real time when the travel mechanism reaches the calibration point position of the first magnet; J1 is the static magnetic grating sensor position data marking the calibration point position of the first magnet; Mn is the actual detected magnet calibration point position of the nth magnet; Pn' is the static magnetic grating sensor position data read by the PLC / controller in real time when the travel mechanism reaches the calibration point position of the nth magnet; Jn is the static magnetic grating sensor position data marking the calibration point position of the nth magnet.

[0083] Further, the offset correction relationship between the position encoder and the travel is:

[0084] Y = k×X + b + ΔY;

[0085] Among them,

[0086]

[0087] ΔY is the offset between the position encoder and the travel; Ym is the position encoder position data calculated by the PLC / controller through the linear calculation relationship used when passing through the previous magnet when the travel mechanism reaches the calibration point position of the mth magnet, Lm is the magnet calibration point data of the mth magnet, Pm' is the static magnetic grating position data read by the PLC / controller in real time when the travel mechanism reaches the calibration point position of the mth magnet, and Jm is the static magnetic grating position data marking the calibration point position of the mth magnet.

[0088] The values of k and b in the offset correction relation between the position encoder and the stroke are determined by the first set of extrapolation formulas and the second set of extrapolation formulas in the linear calculation relation formula. When the PLC / controller has recently calibrated the linear calculation relation of the first magnetic steel, k and b are determined by the first set of extrapolation formulas; when the PLC / controller has recently calibrated the linear calculation relation of the nth magnetic steel, k and b are determined by the second set of extrapolation formulas.

[0089] S5. Use the PLC / controller to calculate the position of the operating mechanism based on the stroke relation of the calibrated position encoder, so as to accurately control the preset target point of the operating mechanism.

Claims

1. A detection, calibration and control method for the stroke and position of an operating mechanism, characterized in that, Including the following steps: S1. Install a position encoder on the wheel set of the running mechanism, make the position encoder rotate synchronously with the wheels, and use a PLC / controller to detect the code value data of the position encoder in real time; S2. Set multiple magnet position points at known distance intervals along the track length direction, install magnets on the ground under the track corresponding to the magnet position points, determine the magnet calibration points according to the magnet position points, and install a static magnetic grating sensor at the lower end of the wheel set of the running mechanism; S3. Start the running mechanism. During the movement of the running mechanism, mark the positions of the calibration points of the position encoder based on the magnet calibration points, and input the position data of the calibration points of the encoder into the PLC / controller; at the same time, mark the positions of the static magnetic grating calibration points corresponding to the calibration points of the position encoder, and input the position data of each magnet calibration point read by the static magnetic grating sensor into the PLC / controller; S4. Use the PLC / controller to obtain the position encoder data and static magnetic grating sensor data of the running mechanism, and implement a dual calibration mechanism including linear calibration and offset correction in a signal edge-triggered manner to calibrate the linear calculation relationship of the position encoder of the running mechanism and the offset correction relationship of the position encoder of the running mechanism in real time; Linear calibration: Based on the position data of the calibration points of the position encoder corresponding to the first and last magnets and the position data of the magnet calibration points, establish a linear relationship Y = k×X + b; where, Y represents the position data of the running mechanism; k and b are the coefficients in the linear calculation relationship; X is the code value data of the position encoder read by the PLC / controller; When the traveling mechanism passes the first magnet, in the linear calculation relationship, M1 = L1 + P1′ - J1; When the traveling mechanism passes the last magnet, in the linear calculation relationship, Mn = Ln + Pn′ - Jn; Where, Ln is the magnet calibration point data of the nth magnet, M1 is the actual detected magnet calibration point position of the first magnet; Xn is the code value data of the position encoder corresponding to the marked position of the calibration point of the nth magnet, and n is equal to the total number of magnets; X1’ is the code value data of the position encoder read by the PLC / controller in real time when the traveling mechanism reaches the calibration point of the first magnet; L1 is the magnet calibration point data of the first magnet, P1’ is the position data of the static magnetic grating sensor read by the PLC / controller in real time when the traveling mechanism reaches the calibration point position of the first magnet; J1 is the position data of the static magnetic grating sensor marking the calibration point position of the first magnet; Mn is the actual detected magnet calibration point position of the nth magnet; Pn’ is the position data of the static magnetic grating sensor read by the PLC / controller in real time when the traveling mechanism reaches the calibration point position of the nth magnet; Jn is the position data of the static magnetic grating sensor marking the calibration point position of the nth magnet; Offset correction: determined based on the position encoder calibration points corresponding to the magnetic steels except the first and the last magnetic steels and the magnetic steel calibration points; during this period, every time the static magnetic grating sensor passes a magnetic steel and passes through the static magnetic grating calibration point position, the position detected by the position encoder is calibrated once, and the relationship between the position encoder and the stroke is updated, and so on, to complete the detection and calibration control of the stroke and position of the operating mechanism; among them, the offset correction relationship is: Y = k×X + b + ΔY; ΔY = Lm - Ym - Jm + Pm’, 1 < m < n; ΔY is the offset between the position encoder and the stroke; Ym is the position encoder position data calculated by the PLC / controller through the linear calculation relationship used when passing the previous magnetic steel when the stroke mechanism reaches the magnetic steel calibration point position of the m-th magnetic steel, Lm is the magnetic steel calibration point data of the m-th magnetic steel, Pm’ is the static magnetic grating position data read by the PLC / controller in real time when the stroke mechanism reaches the magnetic steel calibration point position of the m-th magnetic steel, and Jm is the static magnetic grating position data marking the magnetic steel calibration point position of the m-th magnetic steel; S5. Use the position of the operating mechanism calculated by the PLC / controller according to the calibrated stroke relationship of the position encoder to precisely control the preset target point of the operating mechanism.

2. The detection, calibration and control method for the stroke and position of an operating mechanism according to claim 1, wherein: In the step S1, the position encoder is connected to the wheel set through a coupling, the wheel set drives the position encoder to rotate through the coupling, and the position encoder converts the rotation angle into the position change amount of the operating mechanism.

3. The detection, calibration and control method for the stroke and position of an operating mechanism according to claim 1, wherein: In the step S3, the calibration point of the position encoder refers to the installation position of the magnetic steel corresponding to the position encoder when the operating mechanism is in a stopped state and the magnetic steel is under the static magnetic grating sensor. The PLC / controller reads the current position encoder code value signal, that is, obtains the position encoder code value signal value corresponding to the installation position of the current magnetic steel, which is the position encoder calibration point position.

4. The detection, calibration and control method for the stroke and position of an operating mechanism according to claim 1, characterized in that: In the step S3, the static magnetic grating calibration point refers to when the static magnetic grating sensor moves to directly above the magnetic steel along with the operating mechanism, the vertical distance between the static magnetic grating sensor and the magnetic steel is 0 - 15 millimeters, the static magnetic grating sensor senses the magnetic field information of the magnetic steel, the static magnetic grating sensor will induce magnetic field signals at different positions on its body, and finally output the specific calibration point data of the magnetic steel under the static magnetic grating sensor. The static magnetic grating sensor reads the magnetic steel calibration point data sensed by the static magnetic grating sensor according to the calibration point positions of the position encoder, that is, the static magnetic grating calibration point position.

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