Long-distance absolute position measuring device

Abstract

The utility model discloses a long-distance absolute position measuring device. The magnetic induction displacement sensor is fixed on the mobile equipment and moves along with the mobile equipment, a certain distance range is kept between the magnetic induction displacement sensor and the magnetic mark, and the magnetic mark is subjected to discrete point arrangement along the movement track of the mobile equipment according to a certain coding mode and is kept stationary. And the signal conversion module calculates real-time absolute position information of the magnetic induction displacement sensor relative to the magnetic mark according to a pulse signal output by the magnetic induction displacement sensor through an algorithm, and outputs the real-time absolute position information to the mobile equipment data acquisition module. According to the magnetic induction absolute position positioning device and algorithm based on space coding, high-precision absolute position positioning with the precision reaching the millimeter level and the length reaching the kilometer level can be achieved, good environment adaptability of the device is guaranteed through non-contact measurement of the magnetic induction principle, the service life is long, and cost is low. And the method has high cost advantage and practical value.

Description

Technical Field

[0001] The utility model relates to an absolute position measuring device, in particular to a long-distance absolute position measuring device. Background Art

[0002] Long-distance absolute position measurement devices are widely used in lifting equipment and automated factories. For example, they are used in unmanned intelligent driving, intelligent steel coil warehouses, gantry crane correction systems and other occasions that require absolute position positioning.

[0003] Currently, long-distance absolute position measurement devices include optical ones, such as laser ranging, steel tape coding rulers (CN117516602A, an absolute position detection device and method), and QR code ranging (CN108726369A, a long-distance vehicle positioning system). However, optical long-distance absolute position measurement devices are often used in relatively safe environments, such as indoor areas free of steam and dust. There are also magnetic induction measurement devices, such as CN206705544U (Automatic Positioning, Stacking, and Packing Unbalanced Load Detection System for Container Gantry Cranes) and CN115417176A (An Automatic Material Distribution System for Unloading Carts Based on Gray Busbars). The Gray busbar positioning system disclosed in CN115417176A includes numerous components, including a starting box, a terminal box, a Gray cable, an address transmitter, an antenna box, and an address detector. This system presents challenges such as complex installation, the high cost and easy damage to the coding cable when replacing it, and its inability to be used in some outdoor applications, resulting in numerous application limitations. For example, CN218566408U (a vehicle positioning system using a magnetic encoder) uses a magnetic encoder based on the Hall principle, which has complex encoding rules and is difficult to mass produce.

[0004] Magnetostrictive displacement sensors are widely used for displacement detection of actuators such as hydraulic cylinders or pneumatic cylinders due to their high reliability, high precision, and non-contact characteristics. They are basically used for displacement measurement over short distances (generally less than 20 meters), but have not yet been used for long-range absolute position measurement. Utility Model Content

[0005] This utility model addresses the difficulties of existing long-range positioning technologies, such as complex structures, inconvenient keystrokes, and difficulty in outdoor environments such as steam, dust, and high temperatures. This measurement device proposes a long-range absolute position measurement device. The device has extremely high fault tolerance and anti-interference capabilities. Furthermore, the magnetic scale is simple to install and easy to maintain, and offers a repeatable positioning accuracy of ±0.5mm. It can be used in harsh outdoor environments such as high temperature, high humidity, and dust. It possesses significant technical advantages and excellent environmental adaptability, enabling kilometer-level long-distance position measurement.

[0006] The technical solutions adopted in this utility model are as follows:

[0007] The measuring device includes a magnetic scale, a magnetic induction displacement sensor, a signal conversion module and a signal acquisition module. Several magnetic scales are arranged in sequence along the motion trajectory of the mobile device. A magnetic induction displacement sensor is fixedly installed on the bottom of the mobile device. The magnetic induction displacement sensor is connected to the signal conversion module, and the signal conversion module is connected to the signal acquisition module.

[0008] N magnetic marks are arranged in a continuous interval to form an interval coding component, N≥3; in each interval coding component, the distance between the N magnetic marks forms a unique coding sequence; in two adjacent interval coding components, the distance between the first magnetic mark of the latter interval coding component and the last magnetic mark of the previous interval coding component is set to a fixed value.

[0009] The sensing range of the magnetic induction displacement sensor covers at least N+1 magnetic marks.

[0010] When there are fewer than N+1 magnetic marks within the sensing range of the magnetic induction displacement sensor or the offset distance of the magnetic mark exceeds a preset offset threshold, the signal conversion module sends an early warning signal and transmits it to the early warning module.

[0011] The motion trajectory of the mobile device is a straight line, a curve, or a combination of a straight line and a curve.

[0012] The above one or more technical solutions in the embodiments of the present invention have at least one or more of the following beneficial effects:

[0013] The utility model provides a long-range absolute position measurement device that can realize non-contact induction of magnetic scales through magnetic induction displacement sensors. By arranging the magnetic scales according to certain coding rules, high-precision absolute position measurement at the millimeter level within a kilometer-level measurement range can be achieved. The actual maximum measurement range is related to the coding of the magnetic scales and can reach 2-3 kilometers or even larger.

[0014] The magnetic scales are arranged according to certain coding rules and remain unique within the measurement range of the entire measuring device, thereby ensuring that the measuring device can achieve absolute position measurement.

[0015] The non-contact magnetic induction measurement makes the use of long-range absolute position measurement devices free of fatigue problems such as wear, and has a longer service life and is more stable.

[0016] The magnetic induction displacement sensor and the magnetic mark have good environmental adaptability, and the signal conversion module can be installed in the control cabinet of the mobile device, so that the measuring device can be used in harsh environments such as high temperature, high humidity, rain, dust, and outdoor.

[0017] In summary, the long-range absolute position measurement device proposed in this utility model realizes millimeter high-precision absolute position measurement within a kilometer-level measurement range in harsh environments such as high temperature, high humidity, rain, dust, and outdoor conditions. Its encoding method has extremely high fault tolerance and anti-interference performance, and the system composition is simple and convenient, with extremely low maintenance costs, and has great practical value and promotion value. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic structural diagram of a long-range absolute position measurement device according to an embodiment of the present invention.

[0019] Figure 2 Schematic diagram of long-range absolute position measurement according to an embodiment of the present invention.

[0020] In the figure: magnetic marker 1, magnetic induction displacement sensor 2, signal conversion module 3, connecting cable 4, signal acquisition module 5, magnetic marker pulse waveform 21. DETAILED DESCRIPTION

[0021] The present invention is further described in detail below with reference to an embodiment and accompanying drawings. Obviously, this is only one embodiment of the present invention, but is not limited thereto. All other embodiments derived by those skilled in the art based on the embodiment of the present invention without creative effort are within the scope of protection of the present invention.

[0022] like Figure 1 and Figure 2 As shown, the long-distance absolute position measurement device proposed by the present invention includes a magnetic marker 1, a magnetic induction displacement sensor 2, a signal conversion module 3 and a signal acquisition module 5. Several magnetic markers 1 are moved along the motion trajectory of the mobile device (i.e. Figure 1The dotted lines in the figure) are arranged in sequence and remain fixed. A magnetic induction displacement sensor 2 is fixedly installed on the bottom of the mobile device and moves with the mobile device; the magnetic induction displacement sensor can simultaneously sense the magnetic field of each magnetic mark in the measurement range through the magnetostrictive effect and its inverse effect, realize non-contact sensing, and characterize the position of each magnetic mark through a pulse signal through the electronic unit module inside the sensor. The magnetic induction displacement sensor can respectively measure the pulse signal of each magnetic mark within the sensor range relative to the sensor electronic warehouse, and transmit the pulse signal to the signal conversion module. The magnetic induction displacement sensor 2 is connected to the signal conversion module 3 through the connecting cable 4. The signal conversion module 3 is connected to the signal acquisition module 5. The signal conversion module 3 and the signal acquisition module 5 are both installed in the mobile device. The magnetic induction displacement sensor 2, the signal conversion module 3 and the signal acquisition module 5 constitute a magnetic induction signal acquisition system. The signal conversion module 3 obtains distance information based on the time difference between the magnetic scale pulse waveform 21 and the starting pulse output by the magnetic induction displacement sensor 2 and multiplies it by the wave propagation speed. Based on this, the signal conversion module 3 calculates the distance between each magnetic scale and thus the real-time absolute position of the magnetic induction displacement sensor 2 relative to the magnetic scale. The signal conversion module 3 outputs the real-time absolute position of the magnetic induction displacement sensor 2 relative to the magnetic scale and outputs it to the mobile device data acquisition module 5, thereby forming a long-range absolute position positioning system.

[0023] The lift-off height of the magnetic induction displacement sensor 2 is between 12 mm and 58 mm, and the lateral deviation distance of the magnetic induction displacement sensor 2 is ±40 mm.

[0024] N magnetic marks 1 are arranged at intervals and form an interval coding component, N ≥ 3; in each interval coding component, the distance between the N magnetic marks 1 forms a unique coding sequence, that is, different interval coding components correspond to different coding sequences, meeting the uniqueness requirement; in two adjacent interval coding components, the distance between the first magnetic mark 1 of the latter interval coding component and the last magnetic mark 1 of the previous interval coding component is set to a fixed value, that is, each interval coding component contains an interval code and a position code.

[0025] The sensing range of the magnetic induction displacement sensor 2 covers at least N+1 magnetic marks 1. In this embodiment, N=3, and the sensing range of the magnetic induction displacement sensor 2 covers at least four or more magnetic marks 1. As shown in Table 1, the interval code is 400 mm, and the remaining two variable intervals are position codes. The magnetic induction displacement sensor can detect four magnetic marks at any given moment, i.e., three magnetic mark intervals. These three magnetic mark intervals include both the interval code and the position code.

[0026] The coding table of the magnetic scale 1 is first arranged according to the coding, and then the spacing between each magnetic scale 1 is measured through the learning mode of the signal conversion module 3, so as to obtain the coding information of the magnetic scale 1 actually arranged on site, forming a set of one-dimensional coding tables and saving them in the EEROM data storage unit of the signal conversion module 3. The coding table is shown in Table 1.

[0027] Table 1 is a sample table of magnetic code arrangement of the embodiment of the present utility model

[0028]

[0029] When the magnetic induction displacement sensor 2 moves to cover the n+1th to n+4th magnetic scales 1, the magnetic induction displacement sensor 2 can convert each magnetic scale 1 within its detection range into an electrical pulse signal 21. The electrical pulse signal 21 includes a start pulse 211 and a magnetic scale pulse 212. The signal conversion module 3 calculates the time difference t1, t2, t3, and t4 between the magnetic scale pulse 212 and the start pulse 211 of each magnetic scale, and multiplies them by the waveguide propagation speed c to obtain distance information. Based on this, the distance c (t j+1 -t j ).

[0030] When there are fewer than N+1 magnetic marks 1 within the sensing range of the magnetic induction displacement sensor 2 or the offset distance of the magnetic mark 1 exceeds the preset offset threshold, the system can still work normally. The signal conversion module 3 sends an early warning signal and transmits it to the early warning module for timely processing.

[0031] Finally, it should be noted that the above embodiments and explanations are intended only to illustrate the technical solutions of the present invention and are not intended to limit them. Those skilled in the art will appreciate that modifications or equivalent substitutions to the technical solutions of the present invention may be made without departing from the spirit and scope of the technical solutions disclosed herein, and such modifications or equivalent substitutions shall be encompassed by the scope of protection of the claims of the present invention.

Claims

1. A long-distance absolute position measurement device, characterized in that: The device comprises a magnetic marker (1), a magnetic induction displacement sensor (2), a signal conversion module (3) and a signal acquisition module (5); a plurality of magnetic markers (1) are sequentially arranged at intervals along the motion trajectory of the mobile device; a magnetic induction displacement sensor (2) is fixedly mounted on the bottom of the mobile device; the magnetic induction displacement sensor (2) is connected to the signal conversion module (3); and the signal conversion module (3) is connected to the signal acquisition module (5).

2. The long-distance absolute position measuring device according to claim 1, characterized in that: N magnetic marks (1) are arranged in a continuous interval and form an interval coding component, N≥3; in each interval coding component, the distance between the N magnetic marks (1) forms a unique coding sequence; in two adjacent interval coding components, the distance between the first magnetic mark (1) of the latter interval coding component and the last magnetic mark (1) of the previous interval coding component is set to a fixed value.

3. The long-distance absolute position measuring device according to claim 2, characterized in that: The sensing range of the magnetic induction displacement sensor (2) covers at least N+1 magnetic marks (1).

4. The long-distance absolute position measuring device according to claim 3, characterized in that: When there are fewer than N+1 magnetic marks (1) within the sensing range of the magnetic induction displacement sensor (2) or the offset distance of the magnetic mark (1) exceeds a preset offset threshold, the signal conversion module (3) issues an early warning signal and transmits it to the early warning module.

5. The long-distance absolute position measuring device according to claim 1, characterized in that: The motion trajectory of the mobile device is a straight line, a curve, or a combination of a straight line and a curve.

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